Environmental study of Hogtown Creek in Gainesville, Florida

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Environmental study of Hogtown Creek in Gainesville, Florida
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Florida Water Resources Research Center Publication Number 59
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Huber, Wayne C.
Brezonik, Patrick L.
Heaney, James P.
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University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

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Abstract:
Hogtown Creek Drainage Basin is situated within the growing urban area of Gainesville, Florida. Draining the predominately residential and commercial areas of western Gainesville, Hogtown Creek and its tributaries are being affected by the changing volume and quality of runoff associated with urbanization. These changes are manifested in: 1. increased citizen concern; 2. increased presence of visible and floatable material; 3. increased flows due to greater runoff resulting from increased imperviousness of the area; 4. increased aesthetic degradation; 5. increased turbidity; 6. high fecal and total coliform counts. The creek system is also bearing the impact of an industrial waste and a municipal wastewater effluent. This study was undertaken to analyze the impact of urbanization on the receiving stream. Efforts included: a review of previous investigations and affiliated literature, field surveys, weather monitoring, stream gaging,water quality sampling, sediment sampling, and an examination of benthic communities. The results·of these investigations provide a baseline understanding of Hogtown Creek with regard to climate, geology, soil types, land use, hydrology, ecological communities, point and nonpoint pollution sources, stream flow and water quality.

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Publication No. 59


AN ENVIRONMENTAL STUDY OF HOGTOWN CREEK IN GAINESVILLE, FLORIDA



by




Wayne C. Huber, Patrick L. Brezonik and

James P. Heaney










March 1981


AN ENVIRONMENTAL STUDY OF HOGTOWN CREEK IN GAINESVILLE, FLORIDA



by





Wayne C. Huber, Patrick L. Brezonik and


James P. Heaney


Faculty Investigators


and


Michael G. Cullum, Donald J. Polmann and

Gary F. Goforth

Student Investigators


Dept. of Environmental Engineering Sciences
University of Florida
Gainesville, Florida 32611


Sponsored by

Florida Dept. of Environmental Regulation
Tallahassee, Florida

and

Engineering and Industrial Experiment Station
University of Florida
Gainesville, Florida









ABSTRACT


Hogtown Creek Drainage Basin is situated within the growing urban
area of Gainesville, Florida. Draining the predominately residential
and commercial areas of western Gainesville, Hogtown Creek and its
tributaries are being affected by the changing volume and quality of
runoff associated with urbanization. These changes are manifested in:

1. increased citizen concern;
2. increased presence of visible and floatable material;
3. increased flows due to greater runoff resulting from increased
imperviousness of the area;
4. increased aesthetic degradation;
5. increased turbidity;
6. high fecal and total coliform counts.

The creek system is also bearing the impact of an industrial waste and a
municipal wastewater effluent.

This study was undertaken to analyze the impact of urbanization on
the receiving stream. Efforts included: a review of previous invest-
igations and affiliated literature, field surveys, weather monitoring,
stream gaging, water quality sampling, sediment sampling, and an exami-
nation of benthic communities.

The results of these investigations provide a baseline under-
standing of Hogtown Creek with regard to climate, geology, soil types,
land use, hydrology, ecological communities, point and nonpoint pol-
lution sources, stream flow and water quality.









TABLE OF CONTENTS

Abstract . . . . . . . ii
Table of Contents . . . . .. . iii
List of Figures . . . . . . v
List of Tables . . . . . . vii
Acknowledgements . . . . . . viii
I Introduction and Objectives . . . . 1
Hogtown Creek . . . . . 1
Project Objectives . . . . . 2
II The Gainesville Area . . . . . 3'
Drainage Basins . . . . . 3
Rainfall . . . . . ... 3
Land Use/Population . . . . 7
Geology . . . . . . 7
Soils . . . . . .... 12
III Previous Investigations . . . . . 16
Hydrology . . . . . 16
Ecology .. . . . . . 16
201 Plan . . . . ... . 16
Industrial Waste . . . . . 17
Dredge and Fill Permits . .. . . 17
IV Site Inspections .. . . . . . 18
Objectives . . . . .. . 18
Point Source and Nonpoint Source Locations . . 18
Point Sources . . . . 18
Nonpoint Sources .. . . . 18
Current Flood Management Structures Detention Basins 23
L iin Descriptions . . . . 23
Application of SWMM . . . . 23
Visual Impacts of Stormwater Runoff . . 23
Sampling Network . . . . . 27
V Ecological Survey . . . . . 28
Riparian Communities . . . ... 28
Aerial Phota aphs . . . . . 31
VI Quantity Monitoring . . . . . 33
Stream Flow Gaging . . . . . 33
Weather Monitoring . . . . . 33
VII Stream Quality Monitoring . . . . 37
Introduction . . . . . 37
Methods . . . . . . 37
Sampling Sites . . . . 37
Sampling and Analytical Methods . . 38
Chemical and Physical Characteristics of Stream
Sediments . ..... . . . 40
Benthic Invertebrates . . . . 40
Results and Discussion . . . . 42
Weekly Sampling of Hogtown Creek . . 42
Weekly Sampling of Detention Basins . . 60
Summary of Weekly Sampling . . . 63
Surface Water Synoptic Sampling . . 64
Summary of Synoptic Studies . . . 76
Water Quality in Hogtown Creek during a Storm Event 76
Sediment Studies . . . . 77



iii










TABLE OF CONTENTS

VIII Summary and Conclusions . . . . . 89
Significance of Urban Development . . . 89
Data Base . . . . ... . 90
Water Quality Monitoring . . . . 91
Detention Ponds . . . . . 93

References . . . . . . . 94

Appendix A: Photographs of Detention Basins and Creek Sample
Sites . . . . . . 97
Appendix B: Physical Characteristics of Selected Detention Basins 103
Appendix C: Rainfall Recorded at Gainesville, Florida . 112
Appendix D: Description of Vegetative Communities . . 115
Appendix E: Water Sampling Data . . .. . 120










LIST OF FIGURES


Figure Page

II-1 Location of Gainesville, Florida . . 4

11-2 Drainage Basins in the Gainesville Urban Area 5

11-3 Flood Prone Areas of Hogtown Creek-Existing
Development . . . ... 6

11-4 Proposed Land Use, Gainesville, Florida . 9

11-5 Population Districts, Gainesville, Florida 10

11-6 Soil Types in the Study Area . . 14

IV-1 Location of Sampling Sites and Rain Gages 19

IV-2 Identified Point and Nonpoint Pollution Sources. 21

IV-3 Location of Stormwater Detention Ponds .. 24

V-1 Schematic of Riparian Communities . 29

V-2 Vegetation and Land Use of Hogtown Creek
Drainage Basin . . . 30

VI-1 Minimum Daily, Maximum Daily, Average Monthly
Flows for Hogtown Creek . . 34

VI-2 Monthly Averages of Rainfall, Evaporation and
Creek Discharge . . . 35

VI-3 Daily Rainfall Totals, Gainesville, Florida,
February-July, 1980 . . . 36

VII-1 pH vs. Weekly Sample Period . . 44

VII-2 pH vs. Color, Three Weekly Sites . . 46

VII-3 Dissolved Oxygen vs. Weekly Sample Period 47

VII-4 Nitrate + Nitrite vs. Weekly Sample Period 50

VII-5 TKN vs. Weekly Sample Period . . 51

VII-6 TKN Load vs. Weekly Sample Period . 52

VII-7 Nitrate + Nitrite Load vs. Weekly Sample Period 53

VII-8 Ammonia Load vs. Weekly Sampling Period . 54









Figure Page

VII-9 SRP vs. Weekly Sampling Period .......... .... 56

VII-10 Total Phosphorus vs. Weekly Sample Period 57

VII-11 SRP vs. Weekly Sample Period . . 58

VII-12 Total Phosphorus Load vs. Weekly Sample Period 59

VII-13 Suspended Solids vs. Distance Upstream High
Flow Sampling 4/3/80 . . 65

VII-14 Suspended Solids vs. Distance Upstream Low
Flow Sampling 5/14/80 . . 66

VII-15 Turbidity vs. Distance Upstream High Flow
Sampling 4/3/80 . . . 67

VII-16 Turbidity vs. Distance Upstream Low Flow
Sampling 5/14/80 .. . . ... 69

VII-17: Color vs. Distance Upstream High Flow
S sampling 4/3/80 . .. . ....... 70

VIi-18 Color vs. Distance Upstream Low Flow
Sampling 5/14/80 . . ... 71

VII-19 BOD, vs. Distance Upstream Low Flow
Sampling 5/14/80 . . . 72

VII-20 TOC vs, Distance Upstream High Flow
Sampling 4/3/80 . . . 74

VII-21 TOC vs. Distance Upstream Low Flow
Sampling 5/14/80 . . . 75

VII-22 Cluster Analysis of Fifteen Sites . 76

VII-23 Storm Hydrograph and Conductivity Levels, Single
Rain Event, January 22-23, 1980 .. .. 78

VII-24 TKN and Turbidity vs. Time, Single Storm Event 79

VII-25 Soluble Nutrient Concentrations vs. Time, Single
Storm Event . . ... 79

VII-26 Concentrations of Major Ions vs. Time, Single
Storm Event . . . .. 80

VII-27 Concentrations of Carbon Forms vs. Time, Single
Storm Event . . . 80









LIST OF TABLES


Table Page

II-1 Long Term Average Precipitation . . 8

11-2 Long Term Average Temperature . . 8

11-3 Population by District, Gainesville, Florida 11

11-4 Soil Type Characteristics . . ... 15

IV-1 Location of Sampling Sites and Rain Gages . 20

IV-2 Identified Point and Nonpoint Pollution Sources -
Number of Storm Sewer Pipes ... . 22

IV-3 Location of Stormwater Detention Ponds . 25

V-I Representative Vegetation in Riparian
Cc':'Li ies .... ................. 28

V-2 Vegetation and Land Use of Hogtown Creek Drainage
Basin Index to Figure VI-2 . . 32

VII-1 Chemical andi Bio logical Parameters . 39

VII-2 Biological and Chemical Data Summary for Three
S..eekly Instream Sites . . 43

VII-3 Duncan Multiple Range Test for Selected
Parameters, Weekly Sample Period . 61

VII-4 Characteristics of Stormwater from Florida Sites 81

VII-5 Sediment Analysis Results . . . 82

VII-6 Number of Benthic Invertebrate Species and
Shannon-Weaver Site Diversity, H' .. 84

VII-7 Composite Benthic Invertebrate List. Each Number
Represents the Number of Benthic Organims
per Square Meter . . .. 85










ACKNOWLEDGEMENTS


Gratitude is expressed to the many people and agencies which aided
the study: Ron Ferland of the Alachua County Pollution Control District;
Dave Zeno and Emery Swearingen of the City of Gainesville Department of
Transportation; John Cox, Richard Drew, and John Ruddell of the Florida
Department of Environmental Regulation; the North Central Florida Regional
Planning Council; and the FAA Flight Service Station at the Gainesville
Airport.

At the University of Florida, the Agronomy Department supplied data
and Ron Best, Pete Wallace and Bill DeBusk, from the Center for Wetlands
made ecological evaluations. Within the department of Environmental
Engineering Sciences special thanks are extended to Elaine Wallace for
field samplnzi and chemical analyses and to Randy Schultz for benthic
invertebrate determinations. Among those also responsible for chemical
analyses or other assistance were Charlie Fellows, Carl Miles, Debra
Preble, Jim Butner, Jack Tuschall, Larry Baker, Donna Iozia, Curt Pollman,
Chuck Hendry, Eric Edgerton, Kurt Batsell, Carlos Muniz, Greg McIntyre,
and Bob Chamberlain. Acknowledgement for the unpublished rainfall event
data is extended to L. Baker, B. Debusk, D. Iozia, S. Russell and S.
Zoltewicaz. Computer summaries were prepared by Robert Dickinson and
computer modeling assistance was provided by Stephan Nix. Figures were
drawn by Amy Alford and Anelia Crawford and typing executed by Linda
Trawick, Alicia Maxwell and Jeanette Heeb. Computations were performed
at the Northeast Regional Data Center at the University of Florida.


viii










I. INTRODUCTION AND OBJECTIVES

HOGTOWN CREEK

About two thirds of the City of Gainesville, Florida is drained by
Hogtown Creek, a stream of about ten miles in length along the main
branch, originating in pine flatwoods in the north central part of
Gainesville, and draining to Haile Sink, to the southwest of the City.
Although the tributary land use is predominantly residential, there are
also several commercial and light industrial sites within the approxi-
mately 23 square mile-basin. And, of course, the creek is the recipient
of many miles of highway drainage.

Base flow is provided by continual entry of groundwater from the
surficial aquifer. But, as in most urban areas, the flow during wet
weather consists mainly of nonpoint source runoff from the urban land
uses combined with subdivision drainage ditches and storm sewer outfalls,
although there are still large, undeveloped portions of the flood plain
extant along the creek. As urbanization intensified, especially in some
of the headwaters areas of the creek (e.g., Possum Creek), noticeable
changes have occurred in color, sediment load and visible "pollutants"
(e.g., floatables and foam). At the headwaters of the main branch,
special odor, aesthetic and possible public health problems have arisen
because of seepage of phenolic wastes into the creek. In addition, one
small sewage treatment plant in the Northwood subdivision of Gainesville
discharges into the headwaters of Possum Creek.

Most observers would agree that along most of its length, Hogtown
Creek is aesthe-tically and visually pleasing, with mature mixed hardwood
forests and flood plain swamps. It is popular as a recreation area for
hiking, nature walks, etc. Although not generally perceived as a stream
used for water contact, children frequently play in it. There have also
been instances of tubing in the creek during high water. It is both
anomalous and discouraging that one of the most attractive reaches,
behind the Gainesville Mall Shopping Center, has been the recipient of
well over 100 junked shopping carts. Aesthetic impacts are thus.very
important; however, increasing concern is also being expressed regarding
chemical and biological water quality characteristics. This is especially
relevant downstream, since Haile Sink interacts with the Floridan Aquifer,
a potable water supply.

An interesting feature of the basin is the presence of many storm-
water detention ponds, in place due to a city (and similar county)
ordinance that requires storage of the additional runoff (over and
beyond what occurred under natural conditions) due to development, for a
four year return period storm volume. (According to the City, most
developers actually provide for a ten year storm.) These detention
and retention ponds have been instituted for flood control, but it is
assumed that they also improve water quality because of the detention
provided in the ponds. They also induce groundwater recharge. However,
little is known of a quantitative nature as to the ability of such ponds
to improve water quality.










All of these considerations have led to considerable interest in
Hogtown Creek at a local and state level with regard to the effects of
urbanization and point and nonpoint source runoff on the creek, and the
effect of detention and retention ponds on runoff quality. Are water
quality standards violated? Are beneficial uses such as water supply
and recreation impaired? Is the creek likely to suffer further degrada-
tion? What is its character at the moment? How well do the detention
ponds function? These are some of the questions that have led to this
present study.

The Florida Department of Environmental Regulation (DER) must
prepare plans for control and prevention of nonpoint source water
pollution problems associated with urban activities. Hogtown Creek is
an ideal test watershed for this purpose, in which can be studied impacts
and controls. Specific project objectives follow.

PROJECT OBJECTIVES

1. Evaluate the significance of urban development in terms of
impaired beneficial use of the waters of Hogtown Creek. This is to be
accomplished in part through a literature review, a field survey of the
creek and data collection.

2. Refine the techniques and data base necessary for the above
determination. The methodology used in the study is to be well documented
and data needs specified.

3. Establish a water quality monitoring program at several locations
in the basin to service the needs of objectives 1 and 2.

4. Document the quality performance of selected detention ponds
within the- basin.

A very useful byproduct of the study is the preparation of maps,
tables, etc. that detail the hydrologic, ecologic and demographic charac-
teristics of the Hogtown Creek basin.










II. THE GAINESVILLE AREA


DRAINAGE BASINS

Gainesville is located in the north-central region of Florida, as
illustrated in Figure II-1, and encompasses the major portion of the
metropolitan area of Alachua County. Most of the Gainesville Urban Area
(GUA) lies in an area of approximately 300 square miles from which there
is no surface outflow. All urban, agricultural and wetland runoff in
this area is returned to the upper zone of the Floridan aquifer by a
system of local streams flowing to naturally occurring sink holes. The
principal systems of the urban area are the Sweetwater Branch/Alachua
Sink system, which drains eastern Gainesville, and the Hogtown Creek/Haile
Sink System draining western Gainesville. The proximity of these systems
to other drainage basins in the area is illustrated in Figure 11-2,
which presents an overview of the GUA. Hogtown Creek has its headwaters
in the north-central region of Gainesville and drains in a southwesterly
direction. The major tributary to Hogtown Creek is Possum Creek, contrib-
uting flow from the northwest area of the city. The boundary of Hogtown
Creek Drainage Basin has been delineated in the North Central Florida
Regional Planning Council (NCFRPC) report, prepared by Sverdrup & Parcel,
subtitled Drainage (1974), and is shown in Figure 11-2. The report also
identified sub-basins within the Hogtown System, flood-prone areas (see
Figure 11-3), major -structures, and the topography of the overall basin.
A complete set of maps accompanies the NCFRPC report in scales of 1-
inch:100-feet and 1-inch:200-feet. The basin boundaries are not constant
inasmuch as developments along the perimeter contribute new area through
drainage channels that enter the basin.

Surface flow in the basin receives a contribution from two springs
along the flood channel. In the USGS publication, Springs of Florida,
there is a flow record for Glen Springs, located adjacent to Hogtown
Creek near NW 23rd Blvd. The latest flow measurement was reported in
1972 as 0.30 ft /sec. A second spring is located behind the Gainesville
Mall parking lot, just north of 23rd Blvd. and below the outlet of the
storm sewer pipes. No quantity or quality data were available for this
spring.

The area encompassed by the Hogtown Basin has been reported by
several sources, but with quite a disparity. Christensen et al. (1974)
reported a value of 22 square miles obtained from the Army Corps of
Engineers, while their own calculations showed 27.38 square miles. The
NCFRPC reported 20 square miles, while the USGS reported a value of 41.6
square miles. Based on maps furnished with the NCFRPC report, the total
land area within the basin boundary was calculated on a Hewlett-Packard
model 9864A digitizer to be 22.5 square miles. Inside the boundary are
3 square miles of depression basins which do not contribute surface
flows to Hogtown Creek. Therefore, the total drainage area for the
creek was calculated to be 19.5 square miles.

RAINFALL

Rainfall in the Gainesville area is abundant and temperatures are
mild. Long term monthly averages for rainfall and temperature are


































































Figure II-1. Location of Gainesville, Florida and Hogtown Creek.




4











































) NEWNAN S



PAYNE'S
PRAIRIE 0 1 MILE




Figure 11-2. Drainage Basins in the Gainesville Urban Area.
From North Central Florida Regional Planning Council, 1974.

















































I CLEAR LAKE
2 DOWNSTREAM SR 26A TO 34TH ST.
3 8TH AVENUE
4 SPRINGSTEAD AND PINE FOREST CREEK
5 POSSUM CREEK AT 16TH AVENUE
6 THREE LAKES CREEK AT 34TH ST.


Figure 11-3. Flood Prone Areas of Hogtwon Creeek Drainage Basin Existing Development









presented in Tables II-1 and 11-2, respectively. The yearly average
temperature is about 70F. Rainfall averages about 54 inches per year
and has ranged from as little as 35 inches to as much as 80 inches. In
a typical year about 60 percent of the annual rainfall occurs from June
through September as local afternoon or evening thunderstorms and showers.
Rainfall during other periods is usually the result of large scale
frontal systems. Periods of deficient rainfall occur in many years,
particularly between November and May. Precipitation, temperature and
pan-evaporation in Gainesville are recorded daily at a University of
Florida Agronomy Department station. Data are available through the
National Climatic Center, Asheville, N.C., as part of NOAA Climatological
Data. Various other sources of unpublished data exist in the area such
as the FAA Flight Service Station at the Gainesville Airport and intermit-
tent university studies. Two weighing bucket rain gages were utilized
as part of this study.

LAND USE/POPULATION

Proposed land use within Hogtown Basin is illustrated in Figure II-
4, which summarizes the Comprehensive Land Use Plan developed by the
Department of Community Development, City of Gainesville. The plan is
intended to cover the period 1980-2000. Hogtown Basin is predominantly
a residential area, as is much of Gainesville. Population projections
for Gainesville have been prepared for 18 planning districts by the
Department of Community Development. The districts are shown in Figure
11-5 with-corresponding populations given in Table 11-3. The Metropol-
itan Transportation Planning Organization (a department of NCFRPC)
report entitled Socioeconomic Growth Analysis (1979) established 235
traffic analysis zones in the GUA. For each zone, the number of high
density dwelling units, the-total number of dwelling units and the total
population is reported for 1977, and projected for the years 1990 and
2005.

It may be observed that several of the population zones in the
Hogtown Basin are projected to increase by 2000 or more persons in the
next 20 years. As already mentioned, the increased imperviousness and
intensified land use associated with such an increase in population can
be expected to aggravate water quantity and quality problems within the
creek system.

Whether the proposed natural buffer adjacent to the creek will
actually be provided depends at present upon the generosity of land
owners who may donate the land to the City. If a $2.5 million bond
issue on the November 1981 ballot is approved, the City .could purchase
much of the land. This would be highly desirable since the flow retarding
and cleansing action of the flood plain could thus be preserved. A
moratorium on construction within 25 ft of the creek center line is in
existence since November 1980. It may be expanded in the future pending
various feasibility and engineering reports.

GEOLOGY

The geology and geomorphology of Hogtown Basin are examined in a
thesis by S.R. Marcus (1971) and can be summarized as follows. Alachua










Table II-1. Long Term Average Precipitation, Gainesville, Florida.

Month Rainfall, Inches/Month

January 2.84
February 3.70
March 4.26
April 3.02
May 3.54
June 6.81
July 8.03
August 8.25
September 5.67
October 3.67
November 1.92
December 2.88

Yearly average 54.59 inches

-Period of Record 1941-1970.

From NOAA, Climatological Data
Gainesville Station-3 WSW
University of Florida Agronomy Department




Table 11-2. Long Term Average Temperature, Gainesville, Florida

Month Temperature, F

January 57.0
February 58.6
March 63.6
April 70.0
May 75.8
June 80.0
July 81.1
August 81.2
September 79.1
October 71.8
November 63.3
December 57.8

Yearly average 69.9

Period of Record 1941-1970.

From NOAA, Climatological Data
Gainesville Station-3 WSW
University of Florida Agronomy Department










___________ ~ ~


4


2 7Y 7



7 75


7>7


-r<~j~KY3


5


7


c 4


5 37


3 -l






I 7




'7jN I Q,'T 3 2





3,



ilt S AVF


5
77
----. -- NW 2.3 AVE


7 7 --
2?2
I-



27
5
IT]2 q
5


-5




//


I MILE i

I PLANNED RESIDENTIAL DEVELOPMENT
--2 MULTIPLE FAMILY
3 RECREATION BUFFER
4 INSTITUTIONAL
5 COMMERCIAL/ INDUSTRIAL/ OFFICE/ UTILITY
6 AGRICULTURAL
7 SINGLE FAMILY


Figure 11-4 Proposed Land Use, 1980-2000, Gainesville, Florida
From Department of Community Development, 1979.


5 3a
2 5 5 W. UNIVERSITY AVE C












HALE SINK SW 20AVE/ -- ---^
7 5


FQ-





















































Figure 11-5. Population Districts, Gainesville, Florida.










Table 11-3. Population by District, Gainesville, Florida


POPULATION PROJECTIONS BY PLANNING DISTRICT 1979 2000


1979*


1980


900


1985


1, 200


1990


1,500


1995


1,800


2000


F 2,050


2 4,948 (795) 4,950 54 50 6 22_5 7,000 8,000
3 2,390 2,650 2, 50 3,100 3,350 3,700
4 3,699 (206) 3,850 4,550 5,150 5,750 6,250
5 3,252 3,500 4,000 4,075 4,150 4,200
6 6,916 7,550 8,250 8,850 9,450 9,900
7 2,604 3,150 3,950 4,600 5,250 5,800
4 8 3,922 4,400 5_400 6,550 7,700 9,250
1 9 8,285 (19) 8,200 8,650 9,250 9,850 10,500
10 8,019.(1480) 8,500 9,250 9,950, 10,650 11,550
. 11 5,647 (24) 5,700 6,000 6,650 7,300 8,050
q 12 3,788 3,950 4,750 5,900 7,050 8,500
13 5,187 5,600 6,300 7,600 8,900 10,650
14 6,521 (148) 6,500 7,000 7,700 8,400 9,200
15 8,941(6920) 8,900 8,900 8,900 8,900 8,900
16A 2,166 2,175 2,200' 2,250 2,300 2,350
17A 6,725 6,800 7,400 8,050 8,900 9,800
19A 1,674 1,800 2,300 2,850 3,300 4,000



Total 85,437 89,075 98,400 109,150 120,000 132,650


*Estimated population January 1, 1979.
group quarters.


Figures in brackets represent people living in


Department of Community Development, Planning Division, February, 1979.










County is divided into two major topographic regions, a western karst
plain about 90 feet above sea level and an eastern plateau, the Okeefeno-
kee Terrace, ranging from about 175 feet down to 150 feet above sea
level. Hogtown Creek is now cutting headwards into the plateau, working
to reduce it to the level of the karst plain. The karst plain has been
lowered by solution to the present level of lakes and prairies, at or
near the local water-table base level. The major structural feature of
the area is the Ocala Arch, the crest of which is now occupied by the
karst plain. East of the axis of the arch the Okeefenokee Terrace has
been uplifted to around 175 feet, whereas it is found elsewhere to be
around 120 to 140 feet. The slope of the plateau is eastward. A
distinct drainage divide exists in the Gainesville area between Hogtown
Creek and Little Hatchet Creek. In other areas of the terrace, a distinct
pattern of drainage is lacking. Thus, most of the Okeefenokee Terrace
is a pine-palmetto flatland with extremely poor surface drainage.

Hogtown Creek lies within the Central Highlands physiographic
province of Florida. Gently rolling hills are scattered with sink
holes, and lakes are found at the margins of a flat terrace. Underground
drainage is predominant in these areas, being highly developed west of
Gainesville. Surface runoff dominates in the terraced areas, with much
of the runoff eventually disappearing into sink holes.

One prominent terrace and a secondary terrace extend from near the
headwaters of Hogtown Greek downstream two-and-one-half miles, or about
one-half the length of these tributaries. Incised meanders occur along
the terraced stretches of Hogtown Creek, indicating that the creek has
been subjected to periods of stability and rejuvenation. The rejuvena-
tion consisted of one major post-Aftonian stage and one or more subsequent
events.

Hogtown.Creek flows into a prairie from which there is no surface
drainage. Its base level is the local groundwater level. The drainage
basin exhibits a dendritic pattern throughout due to the uniformity and
horizontal stratification of the underlying material. The level of the
water on the prairie is about 60 feet above sea level. The creek
terminates at Haile Sink, which drains to the Florida aquifer. The
level of the potentiometric surface of the Floridan aquifer is approxi-
mately equal to that of water on the prairie.

SOILS

Figure 11-6 is a map of the soil types in Hogtown Creek Drainage
Basin. The soils are classified with respect to drainage as defined by
the soils descriptions provided in a USDA Soil Conservation Service
Special Soil Survey Report (latest revisions 1979). Along with soil
types, urban areas (where greater than 70% of the surface is impervious)
are designated on the map. Pits and dumps are also shown.

Very poorly drained soils are found in the headwaters and in the
southern reaches of Hogtown and Possum Creeks. Poorly drained soils,
notably those in the Pelham series, make up much of Possum Creek and
comprise the substrate in the area where Possum Creek enters Hogtown
Creek. Moderately well drained soils are found off-stream, adjacent to









the soils which make up the stream bed. The northern and central reaches
of Hogtown Creek are composed largely of well drained soils, notably of
the Kanapaha sand series. The quality and quantity of runoff from these
soils are functions of the characteristics presented in Table 11-4.
Erosion and subsequent sediment loading potential are functions of
particle size and slope. In general, the smaller the particle size and
the steeper the slope the greater the erosion potential. The amount of.
runoff is a function of the imperviousness of the area. Soil permeabil-
ity is reflected in the hydraulic conductivity and moisture capacity
estimates, and ultimately, the drainage classification of each soil
type. The majority of the area in the Hogtown basin contains moderately
well to well drained soils, implying that runoff (from natural land
cover) is relatively low. In the 1974 NCFRPC Drainage study, the basin-
wide average runoff coefficient (C in the rational Q = CiA) was estimated
as 0.37. The effect of increased urbanization on stormwater runoff can
be quantified by determining the increase in the magnitude of C. The
NCFRPC report evaluated the increase in the runoff coefficient based on
projected land use changes, and C was predicted to increase from 0.37 to
0.47 by the year 2000.

















'-'~ 1i7ijKQ<2
I


VERY POORLY DRAINED
POORLY DRAINED
MODERATELY WELL DRAINED
WELL DRAINED
PITS AND DUMPS
URBAN AREAS
LAKES


Figure 11-6.


Soil Types in the Study Area. Note that the whole area is urbanized, and "urban
areas" on the figure means areas with greater than 70 percent imperviousness,
From USDA Soil Conservation Service, latest revisions, 1979.





















Table 11-4.


Hydraulic
Conductivity
(inches/hr)


Soil Type Characteristics (1)


Soil Erosion
Potential (3)
Tons/Acre Rain Factor


Particle Size (% Passing Sieve)
4 10 40 200


Available
Water Capacity
Slope /inches of water
(%) inch of soil


Very Poorly Drained

1. Surrency
2. Samsula (2)
3. Monteocha

Poorly Drained

1. Blichton Fine Sand
2. Pelham
3. Pomoiva
4. Riviera
5. Wachula
6. Pompano
7. Lochloosa

Moderately Well Drained

1. Millhopper Sand
2. Bonneau
3. Tavares
4. Kendrick

Well Drained

1. Kanapaha Find Sand
2. Arredondo Find Sand
3. Gainesville Sand


3.2-11
6,0-20
3.6-i12



2.5-8.2
2.7-9.1
3.5-1.2
5.6-19
2.6-11
>20
2.6-8.5



4.2-14
2.5-8.2
>20
2.2-7.3



3.7-12
5.3-19
6.0-20


100
87-94
100
100
95-100



100
95-100
100
95-100


0.20
0.19
0.17


(1) Soil properties averaged over -80" profiles of < 5 textures.
(2) Values averaged over a 55" profile with the top 36" of muck.
(3) Defined as potential soil loss from "continuous fallow (> 3 yrs)


95-100
95-100
98-100
84-92
96-100
100
95-100



97-100
90-100
95-100
90-100


88-100
80-95
78-95



85-98
69-90
85-100
67-90
90-100
75-100
90-98



75-95
84-95
85-100
82-95


11-26
5-20
9-23



26-37
21-42
9-24
7-17
16-34
1-12
21-34



9-26
21-31
2-8
22-38


95-100 90-100 77-95 13-24
95-100 90-100 75-95 5-40
97-100 95-100 85-100 13-20




on 9% slope, 73' long."


From USDA Soil Conservation Service, latest revisions, 1979.


Soil Type


0.09-0.14
0.14-0.18
0.09-0.14



0.08-0.13
0.08-0.11
0.07-0.12
0.06-0.09
0.09-0.15
0.02-0.05
0.10-0.14



0.07-0.12
0.10-0.13
0.02-0.05
0.11-0.15



0.06-0.11
0.06-0.10
0.07-0.10










III. PREVIOUS INVESTIGATIONS


HYDROLOGY

The issues of flooding, flood control, hydrology of the creek and
detention basins have been addressed in several reports. The most
complete study is the NCFRPC report Drainage (1974), previously mentioned.
In 1973 the NCFRPC presented Report on a Flood Plain and Water Control
Program for the Headwaters of Little Hatchet, Turkey, Blues and Hogtown
Creeks which studied the soil types, hydrology, and runoff character-
istics of the upper reaches of the creek. A drainage study of a region
at the headwaters of Possum Creek was conducted in 1973 by H. Green, a
local consulting engineer. University of Florida studies include Krueger
(1972): a hydrologic evaluation of a proposed natural retention basin;
Vargus (1972): an evaluation of area parameters controlling stormwater
runoff; Christensen et al. (1974): an evaluation of natural detention
sites; Victoria (1974): a computer model of the creek system including
proposed natural detention basins; and Doyle (1973): a study of land
use alternatives addressing water quality control associated with quan-
tity control,

ECOLOGY

The NCFRPC report entitled Open Space and Recreation (1973) pre-
sented a comprehensive evaluation of recreation in Alachua County and
offered proposals for major open space systems and parks for a 1980
program and 1990 plan. The Council advocated a multiple-use concept for
the entire drainage basin and the development of several recreation
areas -al.n the creek. Environmentally Sensitive Areas (1975), a report
by the Department of Community Development, examined the geology, soils,
slopes, land use, vegetation, wetlands and sensitive areas of the Gaines-
ville area.

201 PLAN

The Alachua County 201 Wastewater Facility Plan For The City
of Gainesville, Florida was completed in 1978 by CH2M-Hill, Inc. The
report includes an environmental inventory covering such things as
physiography, geology, soils, ground and surface water hydrology,
climatology, plant and animal communities, environmentally sensitive
areas, and archeological and historic concerns. Also provided are 1975
land use and population data, with projections to 1995. Existing water
quality in the Gainesville area received comprehensive coverage in that
report. Samples at Haile Sink in January, 1971 showed dry-weather
pollution of Hogtown Creek to be "considerable", with biochemical
oxygen demand (BOD) higher during storm runoff. Dry- and wet-weather
water quality data for May and August, 1976, respectively, show moderate
nutrient concentrations and high dissolved oxygen (DO) levels at Haile
Sink. Aquatic biota at Haile Sink were also examined in 1976.. A compre-
hensive background sampling program examining such things as metals,
nonmetals, organic, and physical and biological parameters was conducted
in 1977. Tests covered both groundwaters and surface waters in and
around Gainesville. The 201 Plan also addressed the wastewater treatment










plant discharging effluent to the headwaters of Possum Creek. Discussions
included effluent quality for 1974-1976 and plans to take the plant out
of service in the near future.

INDUSTRIAL WASTE

Probably the most serious pollution problem in Hogtown Basin arises
from phenolic wastes at the former site of Cabot Carbon, a company that
produced pine tar products in the 1950's and 1960's. Lagoons in the
vicinity of Main Street and 23rd Blvd., near the headwaters of Hogtown
Creek, received process wastes such as crude wood oils, acid water and
pitch. As much as 6600 gallons of effluent per day is reported to have
been discharged from these lagoons to a swampy area that fans out to a
ditch leading to Hogtown Creek. An unknown number of lagoons were
covered over after they were filled with settled wastes. As early as
1961, Sundaresan et al. (1965) conducted studies on the effect of lagoon
discharges on the creek. The study concluded that effluent from the site
caused severe water quality degradation and had an adverse impact on
creek biota, with creek recovery occurring 4.9 miles downstream from the
discharge. The company ceased operations in 1966, but major discharges
from unearthed-lagoons occurred in 1967 and 1977 during development and
construction in-the area. A biological survey of the upper 2.8 miles of
Hogtown Creek, conducted by the Florida Department of Environmental
Regulation in October 1977. showed the creek to be devoid of life (except
for bacteria) from the point of discharge to 6000 feet downstream. The
U.S. Environmental Protection Agency conducted a Hazardous Waste Investi-
gation in December 1979. The study found phenol concentrations as high
as 1500 ig/1 in the surface water, as well as 25 other organic compounds
not found elsewhere in the area, 8 of which are listed as NRDC Priority
Pollutants. Stream recovery in terms of a diversified macroinvertebrate
community was reported to occur 5 miles downstream. The Alachua County
Pollution Control District, through its own investigations and the
review of other studies, has concluded that the problem existing today
consists of continuous seepage of highly phenolic groundwater leachate
into the North Main Street drainage ditch, which empties into Hogtown
Creek.

DREDGE AND FILL PSRIlTS

Current dredge and fill permits were reviewed as possible docu-
mentation of physical impact. The City of Gainesville has a five year
permit for dredging associated with maintaining the Hogtown Creek channel
and culvert under N.W. 8th Ave. The permit calls for the soil to be
trucked offsite, but current practice is to pile the spoils along the
adjacent banks, where they are highly susceptible to scour and return to
the creek. Gainesville D.O.T. has a permit for activities related to
the construction of a bridge spanning the creek at N.W. 34th Street near
University Ave. Silt screens were placed 50 feet downstream to control
turbidity. There is no documentation on the effectiveness of these
screens. The bridge construction began after the sampling period ended.










IV. SITE INSPECTIONS


OBJECTIVES

On 23 April, 1980, a group consisting of representatives from the
Florida Department of Environmental Regulation (DER), the city of
Gainesville D.O.T., the University of Florida Department of Environmental
Engineering Sciences, the Alachua County Pollution Control District
(ACPCD), and the University of Florida Center for Wetlands spent the day
visiting the fifteen sampling sites and detention basins. The objectives
included:

I. location of point source and nonpoint source discharges into
Hogtown Creek
2. inspection of current flood management structures
3. discussion of visual impacts of urban stormwater runoff
4. discussion of the sampling program
5. discussion of the hydrological, geological and ecological
characteristics of each site.

The sampling sites, detention ponds and rain gage locations are shown in
Figure IV-1 and Table IV-1.

POINT SOURCE AINTD NONPOI;::. SOURCE LOCATIONS

Point Sources

Presented in Figure IV-2 are the locations of identified point and
nonpoint discharges into Hogcown Creek. Table IV-2 enumerates the
quantity and dimensions of the sources at each location. Figure IV-2
was compiled from storm sewer maps and conversations with personnel from
Gainesville D.O.T. and --.1-D. As indicated, approximately 110 storm
sewer outfalls comprise the majority of the number of point sources. A
sewage treatment plant in the Northwood subdivision near the headwaters
of Possum Creek contributes as much as 0.5 mgd of chlorinated effluent.
The plant was designed for a capacity of 0.35 mgd and utilizes extended
aeration treatment followed by polishing ponds.

Approximately 50 open ditches provide surface drainage for the
majority of the north and northwest areas of Gainesville. Figure IV-2
presents the location of ditches with a top width of 15 feet or greater.
The majority of these terminate along the flood channel of Hogtown and
Possum Creeks. There are also approximately 30 smaller ditches distrib-
uted about the city. The stormwater runoff from these ditches combines
with the effluent from the large number of storm sewer outfalls and has
a major influence on the quantity and quality of flow in Hogtown Creek
following storm events.

Nonpoint Sources

The only documented nonpoint source is located in the northeast
region of the basin near Main Street, where a drainage ditch empties
into the creek after flowing near chemical dump sites once utilized by
Cabot Carbon. As discussed previously this dump site has been documented
to contribute phenolic leachate to the creek.






















































Figure IV-1. Location of Sampling Sites and Rain Gages.
There are no sites numbered 3, 7, 8, 13, 15, 18, 20
due to a renumbering scheme.









Table IV-1. Location of Sampling Sites and Rain Gages.


Sampling Station Location

On-stream Sites

1 Haile Sink
2 Hogtown Creek upstream of NW 34th St.
4 Hogtown Creek downstream of NW 16th Ave.
5 Possum Creek downstream of NW 16th Ave.
6 Tributary to Possum Creek upstream of
NW 24th Terr.
9 Possum Creek downstream of NW 53rd Ave.
10 Possum Creek upstream of NW 39th Ave.
11 Tributary to Possum Creek upstream of
SR S232A (NW 31st Ave.)
12 Possum Creek upstream of NW 34th St.
14 Hogtown Creek upstream of NW 6th St.
16 Tributary to Hogtown Creek upstream
of NW 39th Ave.
17 Hogtown Creek downstream of Howze Rd.
(SW 20th Ave.)
19 Hogtown Creek upstream of NW 23rd Blvd.
21 Hogtown Creek downstream of N. Main St.
22 Hogtown Creek upstream of NW 29th Rd.

Detention Ponds

Dl NW 32nd St. and 24th Ave.
D4 NW 39th Dr. and 14th Place.

Rain Gages

1 10 m from creek 400 m south of 16th Ave.
2 Northwood Sewage Treatment Plant
3 Gainesville Regional Airport (FAA)
4 Bledsoe Drive, Hull Road (300 m east
of 34th St.) (NOAA)










































OPEN DITCHES
.......... 15'-30' TOP WIDTH
----- > 30' TOP WIDTH


Figure IV-2. Identified Point and Nonpoint Pollution Sources.









Table IV-2. Identified Point and Nonpoint Pollution Sources-
Number of Storm Sewer Pipes


Storm Sewer Pipe Diameter, (inches)
Location 12 14 15 18 24 30 36 42 48 60


3 1
2 1

1
1
2 1

2 1
1
2 1


1


1 1
1

1


11*

12
13


1
1 1


1
2 3 1
2

1
2 2
1
2
4 5 1


1 1


1


1 2
2


0.5 mgd effluent from Northwood Treatment Plant








CURRENT FLOOD MANAGEMENT STRUCTURES DETENTION BASINS


Basin Descriptions

During the course of the study, eight detention basins were observed
with respect to their efficiency as flood management devices (See Figure
IV-3 and Table IV-3). Four of the eight detention basins were constructed
as an aspect of subdivision development and were designed to handle the
runoff associated with these areas. These basins are numbered D4-D7 for
the current study. Basins D5, D6, and D7 have similar growth of cattail
and other emergent species. During periods of no rain there is no flow
through these basins, while basin D4 is located in-stream and consequently
has flow when the creek flows. Basins Dl and D3 are hardwood hammocks
modified to handle subdivision runoff. The outlet from basin Dl is
often clogged with debris and/or sand and the area is often ponded for a
period of days following heavy rains. A major discharge process is
infiltration. While the trees in this basin exhibit no signs of stress
as yet, long periods of inundation are thought to be detrimental to
these species (Wharton, 1970). Basins D8 and D9 are natural depressions
located in the stream bed. A ditch has been constructed to carry runoff
from the area south of 16th Avenue to basin D8. This basin is a broad,
nearly level hardwood swamp with open water during periods of high
groundwater. Basin D9 is a sandy depression with a well defined stream
bed. Basin- D2 is a natural pond accepting runoff from surrounding
lawns. A pump is -q-ui:p.-1 to maintain water levels in the pond, and
discharges to a slow-flowing wetlands system to the south. Pictures of
DI, D3, D4, D5 and D7 are presented in Appendix A, along with photographs
of three stream sampling locations.

Application of :L.'-

The Storage-Treatment (S/T) block of the EPA Storm Water Management
Model (l.Ai'. was utilized to model the flow routing through two natural
(Dl and D3) and three man-made (D4, D5 and D7) detention basins. Stage-
to-surface area and stage-to-discharge relationships were evaluated from
the physical dimensions of each basin, and are depicted in Figures B-l
through B-5 of Appendix B and Tables B-1 through B-5 of Appendix B. The
results were used in SWMM to route hypothetical flood conditions through
the units. The S/T block is capable of tracking DO, pollutants, and
particle distributions through the basins and accounts for the processes
of evaporation, settling and decay. Interested parties are directed to
the latest SWMM documentation for further information (Huber et al.,
1980). The results of the SWMM flood-routing exercise are available for
review but are not included in this report. Because of the lower than
average rainfall experienced during the study, there was no opportunity
to verify the effectiveness of the ponds as estimated by SWMMT; of over
100 attempts to gather such data, only 17 samples were collected.

VISUAL IMPACTS OF STORMWATER RUNOFF

Based on observations during the field survey and past experiences
these visual impacts of stormwater impact were noted:

1. Along the northeast reach of Hogtown Creek above 16th Ave and below
39th Ave, a black oily substance was observed along the creek
















































Figure IV-3. Location of Stormwater Detention Ponds.









Location of Stormwater Detention Ponds.


Detention Pond

D1

D2

D3

D4

D5

D6

D7

D8

D9


Location

32nd St. and

41st St. and

38th Dr. and

39th Dr. and

21st Dr. and

21st Dr. and

29th St. and

22nd St. and

31st Dr. and


24th Ave.

6th Ave.

31st Place

14th Place

42nd Place

43rd Place

39th Ave.

14th Ave.

9th Ave.


Table IV-3.










substrate. Associated with this was an abundance of a black fil-
amentous growth. The growth was hypothesized to be a form of
bacteria which was capable of utilizing the oily substance.

2. There was a side slope failure observed in detention pond D5. It
appeared that a combination of surface runoff and a high percentage
of clay in the bank was the cause.

3. From personal observation, the amount of turbidity in Possum Creek
near 16th Ave. has increased over the past 5 years. This was
believed to be due to increased construction in the upstream region.

4. As Hogtown Creek passes under N.W. 29th Rd., sediment loading has
half-filled the 4 foot diameter culverts.

5. The presence of floatable materials characteristic of stormwater
systems was noticed near 34th St., after the confluence of Possum
and Hogtown GCreeks. The high number of stormwater outfalls was
believed to be responsible for this.

6. North of the Northwood Treatment Plant the headwaters of Possum
Creek appeared to have a high turbidity level. A four lane limestone
roadbed traversing the area was identified as the major contributor
of sediment-.

7. Well over one hundred junked shopping carts are in the creek bed
behind the Gainesville Mall (north of NW 23 Ave.).

8. The level of litter, floatables, garbage and refuse (e.g., cans,
bottles, paper, auto parts) is high along most of the creek system,
but is increased downstream of highway storm drains (e.g., NW 6 St.,
NW 23 Ave., NW 16 Ave., NW 34 St.).

9. The water in the creek is dark and the bottom not visible from its
headwaters near N- Main St. almost to NW 6 St. There is also foam
where the water flows rapidly. Presumably this is a result of the
phenolic leachate at the headwaters.

10. Portions of the flood plain are used for dirt bike trails, with
considerable damage to the soil surface (e.g., to the west of
Hogtown Creek, south of SW 2 Ave.). Erosive potential during
overland flow to the creek during storms is thus greatly increased.
Since much of the flood plain is still privately owned, the City
has no control over recreation and land use in those areas.

11. At several locations along upper reaches of the Main Branch, construc-
tion has occurred very near the narrow channel and steep banks of the
stream, and slope failures have occurred. "Sea walls" or retaining
walls have not all withstood the erosive potential of the creek.











SAMPLING NETWORK


During the field survey, the rationale for selecting the sampling
network was discussed. Known point sources such as the Northwood treatment
plant~were bracketed, as were stream confluences. Also, many sample
sites were located adjacent to major roads in an attempt to document
their effect.









V. ECOLOGICAL SURVEY


RIPARIAN COMMUNITIES

As a supplement to the field survey approximately 100 color slides
were reviewed by three plant ecologists from the Center for Wetlands at
the University of Florida. These slides surveyed the sampling sites and
the flood management structures and were discussed with respect to:

1. type and age of ecosystem
2. dominant species
3. hydroperiod.

From this meeting, the schematic in Figure V-1 was compiled. As shown,
the riparian communities of the creek are predominantly mixed hardwood
flood plain systems. The northeast branches originate in pine flatwoods
and various wetland systems. The central reaches flow through mixed
hardwood hammocks while the southern downstream reaches pass through wet
prairies and marshes before leaving the surface via Haile Sink. Table V-
1 shows representative species lists prepared from work done by Snedaker
and Lugo (1972) on the ecosystems of the Ocala National Forest. Species
included in Table V-1 have been observed in the respective communities
along Hogtown Creek.

Table V-1. Representative Vegetation in Riparian Communities

Mixed Hardwood Flood Plain Community Length of hydroperiod 0-30 days
Larel Oak Red Maple
Magnolia Durand Oak
American Holly Black Gum
Sweet Gum (Red Gum) Loblolly Bay
Pignut Hickory Sand Live Oak
Iron Wood (Hophorn Bean) Loblolly Pine
Flowering Dogwood Spanish Moss

Wet Prairie/Swamp Length of hydroperiod 220-315 days
Coontail Cattails
Naiad Water Lettuce
Spadderdock

Fresh Water Wetlands Length of hydroperiod 290-365 days
Pond Cypress Button Bush
Black Gum Holly
Wax Myrtle Duck Weed

The type of ecological community present in an area is sensitive to
the length of hydroperiod. This sensitivity is manifested by species
alterations-in areas of altered hydrology, documented in cases of both
drainage and impoundment. Possible changes in the hydrologic regime
attributed to increased urbanization could result in vegetation changes,
with more tolerant species replacing present ones. For instance, land
drainage will alter the communities in an "upward" direction in Table
V-1, whereas increased flooding or impoundment can kill elements of the
flood plain community and convert them to a wetlands or swamp. The
combined effects of altered quality of the water has not been documented.



































SPINE FLATWOODS
FRESHWATER, WETLANDS,
WET PRAIRIES
MIXED HARDWOOD FLOODPLAIN


Schematic of Riparian Communities











2 2;?1
25 ~2 7

12-

12 22i 25f
12~2 2512 13~J& + [f




23, 4S
2 C3--j .;
F-4
1v
26 *5Q r










42igreV


21 1




95 [25


6
34> a"/^ *





4 W l 4
44


4___


-I







2. Vegetation and Land Use of
Hogtown Creek Drainage Basin
From Brown, et al., 1977.









AERIAL PHOTOGRAPHS


As an alternative approach, results from a 1977 vegetation and land
use study of the St. John's River watershed (Brown et al., 1977) were
obtained from the Center for Wetlands. The Hogtown Creek drainage basin
is presented in Figure V-2. Table V-2 identifies the numerical
classification system. The maps were prepared from infrared aerial
photographs taken in 1971.









Table V-2. Land Use and Vegetation of Hogtown Creek Drainage Basin-Index
to Figure V-2.


Unit # Classification

1 Openland
2 Recreation
3 Low Density Residential
4 Medium Density Residential
5 High Density Residential
6 Industrial
7 Mining
8 Commercial and Services
9 Institutional
10 Transportation
11 Utilities
12 Improved Pasture
13 Cropland
14 Citrus
15 Nursery
16 Confined Feeding
17 Planted Pine
18 Clear Cut
19 Other
20* Grassy Scrub
21 Sand Pine Scrub
22* Sandhill Community
23* Pine Flatwood
24* Xeric Hammock
25* Mesic Hammock
26* Hydric Hammock
27 Hardwood Swamp
28 Riverine Cypress
29* Cypress Dome
30* Bayhead & Bogs
31* Wet Prairie
32* Freshwater Marsh
33 Rivers and Streams
34 Lakes and Ponds

Description provided in Appendix D.


From Brown et al., 1977.









VI. QUANTITY MONITORING


STREAM FLOW GAGING

Discharge from Hogtown Creek is gaged by the U.S. Geological Survey
(USGS) at S.W. 20th Ave in Gainesville, station number 02240954, utilizing
a stage recorder. Data are published as part of Water Resources
Data For Florida and are available for the period of record December
1971 to the present. Discharge was previously gaged at Newberry Road in
Gainesville by the USGS, with data available for the period 1959-1974.
Flows in Hogtown Creek are widely varying about the yearly average value
of 21 cfs (for the period 1972-1978). Values for minimum daily, maximum
daily and average monthly flows in Hogtown Creek are shown in Figure VI-
1. Variations in daily discharge from the basin are closely related to
weather changes, with extremes corresponding to precipitation patterns
and major storm events. The relationships between monthly average
values of rainfall, evaporation and creek discharge are depicted in
Figure VI-2. Evaporation over the basin was approximated as 0.8 times
measured pan evaporation.

WEATHER MONITORING

The monitoring of meteorological conditions consisted of the collection
of rainfall data from two stations within the basin and two stations
outside the perimeter. Figure IV-1 shows the location of these stations.
Station #1 was established 10 meters from the creek in the center of the
basin. Station #2 was located at the Northwood treatment plant and was
maintained along with Station #1 by project personnel. Station #3 is
the F.A.A. Flight Service Station located at the Gainesville Regional
Airport. Station #4 is part of the University of Florida Department of
Agronomy weather station. Daily rainfall totals recorded at each
station are presented in Figure VI-3 and Table C-1 (Appendix C). The
differences in magnitude and frequencies reflect the characteristic
nonuniform density of basin rainfall. Individual event records for
Station #1 and #2 are available. Compared with long term monthly means,
rainfall during February through June was 26.4 percent (5.6 in) below
average values. This lack of rainfall hindered efforts to gather wet-
weather data, particularly from the detention ponds. With soil moisture
conditions low, there was probably less runoff from pervious areas than
in previous years. As monthly flows were not obtained from the USGS
station which provided the flow histories in Figure VI-1, there was no
comparison to indicate that flows were proportionally lower than historical
averages.




























































J F M A M J J A S O N D

TIME, months


Figure VI-1.


Minimum Daily, Maximum Daily, Average
Monthly Flows for Hogtown Creek
From USGS Water Resources Data for Florida, 1972-1978.
USGS Gage 02240954 at S.W. 20 Ave.























































J F M A M J J A S O N D


TIME, months


Figure VI-2.


Monthly Averages of Rainfall, Evaporation and
Creek Discharges.
From USGS Water Resources Data for Florida, 1972-1978.
USGS Gage 02240954 at S.W. 20 Ave.
Drainage area = 22.5 mi2.











MAR APR


MAY JUN


JUL I STAT ION


.Li1L~-~


I 1 11,l


II I


Figure VI-3. Daily Rainfall Totals, Gainesville, Florida, February-July, 1980


2.0

1.0


FEB


I Ii


u,
0
.C
0


LL
2


>-
.J


2.0 _
2.0


1.0-


2.0-



1.0
2.0-


FEBr TI


i


i I { I[ II il li l I lilt; I 11 I i III ....















VII. STREAM QUALITY MONITORING


INTRODUCTION


A monitoring program was established for Hogtown Creek to evaluate
general water quality conditions. The program was designed to provide a
data base for the evaluation of urban development upon the watershed. In-
stream stations and detention ponds were sampled on a routine basis, and
synoptic surveys were conducted under low and high flow conditions. In
addition, a detailed hydrograph and sampling program was undertaken for a
rain event in January of 1980.

A list of chemical and biological parameters sampled during the moni-
toring phase of the project is presented in Table VII-1. The parameters
included nitrogen and phosphorus species, TOC and BOD common biological
indicators as suggested by DER in Section 17.3.09 of Water Quality Standards,
common cations and anions, and physical constituents. The breadth of anal-
ysis is fairly comprehensive in terms of water chemistry and should provide
a good initial data base for further studies. However, the project was not
undertaken with the purpose of determining whether or not the creek meets
all relevant standards for Class 1II (recreational) waters in the State of
Florida. In particular, no measurements were made for specific heavy metal
and organic contaminants that might be associated with urban runoff, and
further studies would be required to assess the impact of urbanization on
the levels of those parameters in the stream.

Previous data concerning Hogtown Creek have been collected by various
agencies. The most recent information was collected by the DER in late 1979
and early 1980 at four general locations. The data consist of common physical
parameters in addition to some nutrient analyses. Several biological studies
also have been conducted, one in 1979 (Crisman, unpublished data) and one in
1977 by the DER. A study concerning the problem of phenolic waste in the
stream was conducted by the University of Florida (Nisson 1974).


METHODS

Sampling Sites

Fifteen sampling stations were chosen for chemical and physical con-
stituent analysis during both high and low flow conditions. These stations
were chosen for their proximity to possible point source discharges, storm
water outfalls or other contributing pollutant sources. The sites are iden-
tified in Figure 11-4. Possible point sources included secondary waste
treatment plant effluent between sites 9 and 10, an aromatic hydrocarbon
(phenolic) contributor between sites 14 and 21, and a 60 inch storm drain
from the Gainesville Mall parking lot upstream from site 19.









Three gaging sites (sites 2, 4 and 5) were sampled for fifteen consec-
utive weeks, to determine mass pollutant loadings. Site 2 is located down-
stream of the junction of Possum Creek with the mainstream of the Hogtown
Creek at NW 34 St. and Newberry Road, while sites 4 and 5 are located on
the mainstream and on Possum Creek, respectively, where they intersect NW
16 Ave.

Two detention basins were sampled concurrently with the three streams
sites, Sample site D4 consisted of an in-stream detention basin, and was
sampled at its effluent end. Site number Di, an off-stream detention basin,
was dry during nine of the 15 weeks, and was sampled at its influent end,
due to a recurring constriction in the effluent end. No flow measurements
were attempted at sites D4 and Dl. These sites also are shown on Figure
11-4.

Sampling and Analytical Methods

Samples were collected in clear plastic containers, except for coli-
form and streptococcus analysis, which were collected in sterile glass
bottles, and chlorophyll a, which were collected in brown plastic bottles.
The nitrogen and phosphorus series, along with TOC, were preserved with
40 mg HgCl,/L. All samples were cooled to 3-50 upon arrival at the labora-
tory within two hours of collection in the field.

Field measurements included pH with a Fisher model 1500 portable pH
meter, conductivity with a YSI model 33 S-C-T meter, dissolved oxygen with
a YSI model 54 oxygen meter, visibility with a Secchi disk, and temperature.
Flow measurements were made with the use of an Ott current meter in conjunc-
tion with cross sectional area measurements of the stream at the sample site.
In addition, hydraulic calculations utilizing an existing broad crested weir
located at site two were used for comparison purposes. The calculations were
made using the equation for such weirs (Q = CLH ) (King and Brater 1963).

Analyses for BOD., coliforms, and streptococcus were begun immediately
upon arrival of the samples in the lab or in the case of BOD5, no later than
24 hours after sampling. Turbidity was measured against known standards on
a Hach model 2100A turbidimeter. TOC was determined with a Beckman Model 915
total organic carbon analyzer. Cations were run on a Varian atomic absorption
spectrophotometer, with a hollow cathode lamp and flame atomization. Alkalinity
and suspended solids were determined according to Standard Methods (APHA (1976).
Color was analyzed colorimetrically after centrifugation of samples on a Perkin
Elmer 550 spectrophotometer at 420 nm, and compared to standard chloroplatinate
solutions.










Table VII-1


Chemical and Biological Parameters1


Nutrients
TKI
NH, -N
NO --N
NO -+NO -N
Total-P
Ortho-P



Major Ions
K
Na
:Mg
Ca 9_
SO'2-
Cl4


Organic Matter
TOC
BOD_


Biological Parameters
3
Chlorophyll a (mg/m3)
Total Coliforms (colonies/100 mL)
Fecal Coliforms (colonies/100 mL)
Fecal Streptococcus (colonies/100 mL)


Physical Parameters
Flow (cfs)
pH
D.O.
Temp (C)
Turbidity (NTU)
Alkalinity as CaCO
Conductivity (pmholcm)
Transparency (cm)
Color (CPU)
Suspended Solids


SUnits of expression in mg/L except where noted in parenthesis.

Total Kjeldahl nitrogen was determined with a micro digestion method
which entailed pipetting 10.0 ml of unfiltered sample into a test tube,
addition of 2.0 ml of sulfuric acid reagent described in APHA (1976) and
digesting on a hot plate for an average of 5 hours. The samples were then
allowed to cool and brought back to volume with 10.0 ml de-ionized water
and vortexed. Samples were left to settle out boiling chips overnight and
then poured into AutoAnalyzer cups and capped. They were then analyzed
against digested ammonium standards on a Technicon AutoAnalyzer II using the
indophenol procedure, as outlined in Standard Methods (APHA 1976).

Ammonium was measured by the indophenol procedure on the AutoAnalyzer
in a fashion similar to the digested Kjeldahl nitrogen samples. Nitrate and
nitrate + nitrite-N were analyzed according to the automated cadmium reduc-
tion procedure (U.S. EPA 1975), except that a cadmium wire was used for the
reduction of nitrate to nitrite instead of a column of cadmium granules.

Total phosphorus was determined by pipetting 10.0 ml of unfiltered
sample into a test tube and adding 1.5 ml of 0.5 g/100 ml potassium persul-
fate, 0.1 ml of 0.5 g NaCl/50 ml and 0.5 ml of 11 N H 2SO. The samples were
then vortexed and autoclaved for one hour at 15 psi. After cooling, 0.5 ml
of 11 N NaOH was added to the samples and to standards that also had gone
through the above process. Addition of 1.5 ml of combined molybolate-ascorbate









reagent (APHA 1976) to each sample and standard preceded the measurement of
absorbance at 880 nm. Filtered orthophosphate samples (soluble reactive
phosphate, SRP) and undigested standards were analyzed in a similar fashion
minus the preliminary digestion steps.

Chloride and sulfate were run according to automated procedures in
Standard Methods (APHA 1976). Chloride analysis used the mercuric nitrate
method adjusted for use on a Technicon AutoAnalyzer II, while sulfate anal-
ysis was conducted with the methylthymol blue method, once again on an Auto-
Analyzer.

Total coliform, fecal coliform and fecal streptococcus tests were per-
formed according to Standard Methods (1976), with preparation of all samples
completed within 12 hours of collection. An arithmetic average for the most
readable colonies was determined. Duplicate plates were prepared for all
samples.

Chlorophyll a was determined by Standard Methods (APHA 1976), with the
following exception. The sample was shaken to insure homogeneity and then
filtered through a 0.45 pm filter with a syringe apparatus in lieu of centri-
fugation of the filter/acetone mixture.

Chemical and Physical Characteristics of Stream Sediments

Ten stream sediment samples were analyzed for particle size distribu-.
tion using W.S. Tyler Co. U.S. standard sieves. Samples were separated into
three particle size ranges: >2000 pm for gravel, >63 and >2000 pm for sand
and <63 pm for clay. The sediments were then dried at 105C, after which the
remaining analyses were performed.

The sediment samples were analysed for total phosphorus by a modified
persulfate digestion method (APHA 1976) in which 200 mg of well ground dried
sample was digested and analyzed by the single reagent colorimetric method,
using digested standards to prepare the standard curve. Total nitrogen was
computed by combining results for nitrite + nitrate and total Kjeldahl nitro-
gen. Nitrate + nitrite was measured using a sulfuric acid dissolution fol-
lowed by colorimetric detection (U.S. EPA 1969). Total Kjeldahl nitrogen
was determined by digesting a dried aliquot of sediment with sulfuric acid
reagent (EPA 1969), and analyzing the digestate according to the method men-
tioned earlier for TKN measurement of water samples.

Metal analyses were run on a Varian Technicon model 1200 atomic absorp-
tion spectrophotometer following digestion in concentrated nitric acid.
After ashing at 400C, the sample was redissolved in a nitric/hydrochloric
acid mixture, heated gently, cooled, and measured against digested standards
(U.S. EPA 1969).

Benthic Invertebrates

Benthic invertebrate communities were sampled at 16 stations along Hogtown
Creek. Station locations can be seen in Figure 11-4. Single grabs were
taken in both a pool and a riffle area at each station, for a total of 32
samples. The importance of stream flow and sediment characteristics in the









distribution of benthic communities has been discussed by Hynes (1972).
Samples were taken with a Petit Ponar Grab (Powers and Robertson 1967) with
a sampling area of 0.022 m Samples were washed in the field through a
0.66 pm mesh sieve to remove excess sediment. Remaining organisms were
preserved in 10% formalin and stained with rose bengal. Samples were sorted
in a white pan in the laboratory and identified using both a dissecting
and a compound microscope. Taxonomic references used in the identification
of benthic invertebrates include Pennak (1953) and Edmondson 1959).









RESULTS AND DISCUSSION


A summary of the biological and chemical data collected on Hogtown
Creek is presented in Table VII-1. The values represent means of all
data for the parameters sampled at all 16 sampling locations over the 15
week field phase of the project. The parameters include the common nu-
trient species, TOC and BOD,, common biological indicators, major cations
and anions, and physical conditions. The breadth of analysis is fairly
comprehensive and should provide a good data base for further studies.


Weekly Sampling of Hogtown Creek

As described in the previous section on sampling methods, three in-stream
sites were sampled weekly for 15 consecutive weeks. Site 5 is located on
Possum Creek Branch at NW 16th Avenue. Site 4 is also at NW 16th Avenue
on the main branch of the creek, and site 2 is downstream of the confluence
of the two branches at NW 34th Street and University Avenue.


Flow. Flowing water was present at all three sites during the entire
sampling period. Flow data are presented in Appendix E, along with arithmetic
means and standard deviations. Flow measurements at sites 2, 4 and 5 varied
with antecedent storm activity, as expected (Figure VI-3). A high flow was
recorded during the comprehensive sampling period on April 14; lowest flow
was recorded on-February 27. The two tributaries (Sites 4 and 5) averaged
0.41 and 0.23 m /s (14.6 and 8.3 cfs) respectively, and the downstream site
(2) averaged 1.32 m/is (46.6 cfs). Thus about 50% of the flow at station 2
could be attributed to stream flow previously passing through stations 4 and
5, and the remaining flow apparently was contributed by the adjacent watershed
and other minor tributaries. A low lying poorly drained area (swamp) between
site 2 and the upstream sites (Figure 11-3) could have a substantial positive
impact on the flow at site 2 during dry weather conditions. This area also
may serve as a detention basin during periods of high flow, and this may
further explain the difference between measured flow at site 2 and the sum of
the measured flows at the upstream sites.

Flows were also calculated at site 2 using theater level height
above a broad crested weir and the equation Q = CLH (King and Brater 1963).
The average calculated flow was approximately 18% greater than the average
from current meter readings, and higher percentage deviations occurred during
storm flow periods. Water height above the weir was very small and was esti-
mated with a hand ruler; this most likely accounts for the slight discrepancy.

pH. The pH levels at the three stream sites averaged between 7.00 and
7.15, but showed considerable temporal variability, as well as some spatial
variability on any given sampling date (Figure VII-1). All the values recorded
for sites 2 and 5 were between 6.0 and 8.5 and thus are within the allowable
range for Florida Class III waters. Site 4 had values slightly outside this
range on two occasions (5.9 on March 4 and 8.7 on March 11). There is no
evidence that these variances from the Class III standard were the result of
cultural activity, and they apparently represent natural fluctuations in stream










TABLE VII-2 Biological and Chemical Data Summary
for Three Weekly In-Stream Sites.

Parameter Site 2 Site 4 Site 5

Temperature (C) 16.5 17.3 16.6
Stream flow (CFS) 46.6 14.6 8.3
Turbidity (JTU) 10.1 9.8 9.5
Transparency (m) 0.34 0.21 0.17
Color (PC Units) 171 202- 134
Conductivity (pmho/cm) 170 172 172
Dissolved Oxygen 7.9 7.9 8.0
BOD(5-day) 2.5 2.4 2.4
pH 7.0 7.2 7.0
Alkalinity (as CaCO3) 65 70 57
Suspended Solids 11 11 10
NH -N 0.05 0.06 0.24
NO2-N 0.02 0.05 0.02
TKN 0.93 0.92 1.23
NO2 + NO. N 0.55. 0.20 0.83
SRP 0.88 0.46 1.23
TP 1.10 1.31 2.17
TOC 29 33 22
Ca 40 34 28
Mg 4.7 4.2 4.6
Na 7.6 7.8 9.2
K 8.3 7.9 5.7
Cl 13.6 13.1 14.8
SO-2 14.6 15.7 15.7
4
Total Coliforms (MPN/100ml) 31,200 34,500 31,200
Fecal Coliforms (MPN/10Oml) 510 2,660 1,200
Fecal Strep (MPN/lOOml) 600 980 580
Chlorophyll-a (Ug/l) 1.5 1.0 0.67


Values reported in mg/L unless otherwise noted.























































1 2 3 4 5 6 7 8 9 10 II
WEEK OF EVENT


Figure VII- 1 pH vs. Weekly Sample Period

44


12 13 14 15










pH. The pH values at the three sites generally were within a range of
one unit on any given date. No correlation between flow and pH could be
discerned for any of the three sites (r = 0.08, -0.08 and 0.11 for sites
2, 4 and 5 respectively). Interestingly, there also was no correlation
between stream pH and organic color levels (Figure VII-2), in spite of
the fact that color levels were high (albeit variable) and organic color
is composed of acidic macromolecules derived from decomposition of vegeta-
tion.


Dissolved Oxygen and Temperature. Dissolved oxygen levels during the
15 weeks of monitoring normally were well above the minimum level of
5.0 mg/1 in the State of Florida for Class III waters. Concentrations aver-
aged around 8.0 mg/L for the three stream sites (Figure VII-3), and the
minimum recorded concentration (4.9 mg/L) was the only value below the state
standard. Higher values (near saturation) were evident in the early stages
of the study, and concentrations exceeded 10 mg/L in some instances, reflect-
ing the cooler temperatures at that time. The water temperature during the
study was initially around 100C, and it warmed to around 200C by the sixth
week, (March 11). Temperatures in the low 20C range were maintained from
that point to the end of the study at all three stream sites.


Transparency, Turbidity, Color and Suspended Solids. Transparency was
unrestricted to the stream bed in all cases except during the extremely high
flows measured on April 3. 1980. Hogtown Creek is a rather shallow water
course (usually < 30 cm), and transparency measurements have little signifi-
cance under this condition. Turbidity reached maximum levels on April 3 (30,
41 and 46 NTU at sites 2, 4 and 5 respectively). At a given site, high to
moderate correlations were observed between turbidity and flow rate. This
trend would be expected, since particulate matter is more easilY2suspended
during higher flow conditions. Coefficients of determination (r ) for turbi-
dity with flow were 0.31, 0.74 and 0.76 for sites 2, 4 and 5, respectively.
Overall, turbidity levels averaged about 10 NTU for the three sites over this
sampling period. Although this average is relatively low for flowing waters,
it is higher than values reported for non-urbanized rivers in northwest Florida.
Values averaging between 1.5-2.5 mg/L are common for the Suwannee, Steinhatchee
and Aucilla rivers (USGS 1979), with a maximum values around 5.0 mg/L. The
average of the low-flow turbidity levels for Hogtown Creek is 5.3 mg/L indi-
cating that high flow was not entirely the cause of the relatively high turbidity
in the Creek.

2 Suspended solids had a surprisingly 19w correlation with stream flow
(r = 0.01) and only a fair correlation (r = 0.22) with turbidity. This sug-
gests that the data on suspended solids are probably not highly reliable; the
relatively low precision is a reflection of the generally low concentrations
of TSS in the stream.
2
Dissolved organic color also was correlated with flow rate (r = 0.55
for three sites). Overall, Hogtown Creek is a highly colored stream, and in
that regard is typical of many streams in this region of Florida. The mean
color level for the three sites over the field sampling period was 170 CPU,
and values as high as 615 CPU were observed on occasion. Color also had a





















SYMBOL SITE
2
A. 4
0 5


0
0


0 0


200

COLOR, pcu


300


Figure VII-2 pH vs Color, Three Weekly Sites


S0
0


r2
0.04
0.01
0.01


7.0 O


6.0




5.0




4.0


400















12.0


.-* SITE 2
--- SITE 4
o--o SITE 5
10.0-



S8.0



t 6.0



4.0 -



2.0 -




1 2 3 4 5 6 7 8 9 10 II 12 13 14 15

WEEK OF EVENT


Dissolved Oxygen vs Weekly Sample Period


Figure VII-3









2
moderate correlation (r = 0.26) with turbidity. The color and turbidity
correlation can be explained on the basis of runoff characteristics; storm
water runoff should bring higher concentrations of suspended matter and leach
more organic color from surrounding land areas than would be present in low
(base) flow conditions.

Major Ions. The four major cations (calcium, sodium, magnesium and potas-
sium) were present in the relative abundance of 14-3-2-1, respectively
(as meq/L). Individual listings of the data, along with average values are
given in Appendix E. Values for the four cations were fairly consistent
through the study period. Cation levels are a function of the surrounding
geologic structure, as weathering processes dissolve and leach them from
soils in the watershed and introduce them into the water system. The Hog-
town Creek area is underlain by limestone and its surficial soils are sandy
with very low cation exchange capacities. Under these circumstances, cal-
cium would be expected to be the main cation.
2
Calcium did not correlate significantly with either flow (r = '.12)
or conductivity (r = 0.05). Magnesium and sodium on the other hand, both
correlated negative with flow (r 2Mg) = 0.40; r (Na) = 0.31) and positively
with conductivity (r (Mg) = 0.48; r (Na) = 0.39). Magnesium and sodium were
present in small quantities composed to calcium; nonetheless, it appears
that ions other than calcium control the flow-related conductivity levels.

Alkalinity measurements showed little difference between2the three
sites and had a significant correlations with conductivity (r = 0.49) and
with flow (r = 0.34). The anion ratio was 4-1-1 for alkalinity, chloride,
and sulfate, respectively (all in meq/L). Thus alkalinity is the controlling
anion in terms of conductivity fluctuations associated with flow in Hogtown
Creek.


Organic Matter. Biochemical oxygen demand (BOD5) averaged 2.5 mg/L for
all samples taken at the three sites. This average is in the low range of
data reviewed (Weibel et al. 1963; Mattraw and Sherwood 1977; Wanielista
et al. 1977; and Burton et al. 1979) for various urban storm water runoff
studies. A high standard deviation (2.0 mg/L) relative to the mean value
was observed in the data set. This variability could be accounted for by
the correlation of BOD5 with flow (r = 0.36), which 1lso fluctuated substan-
tially. BOD5 was correlated moderately with color (r = 0.48); i.e. varia-
tions in organic color explain about half the variation in BOD Because
organic color itself is relatively refractory and has little B8D, the correla-
tion is likely to be a co-effect of flow rather than a cause of BOD5. High
flows export more particulate matter off the land, including both refractory
organic (color) and biodegradable organic than2do low flows. As was stated
earlier, color also correlated well with flow (r = 0.55).

Average values of total organic carbon (TOC) for the in-stream samples
ranged from 22.2 mg/L at site 5, to 32.5 mg/L at site 4. An analysis of
variance and Duncan's multiple range tests for the three sites were performed
on the TOC data, and it was found that TOC levels along Possum Creek (site 5)
were significantly lower than those observed along the main stem of Hogtown









Creek (sites 2 and 4). This suggests a source of TOC above site 4, which
carried an impact in terms of TOC concentration as far do nstream as site 2.
As expected, TOC was co related (moderately) with BOD5 (r = 0.38) and also
with total coliforms (r = 0.34).

Nutrients. Nitrogen levels recorded for the creek fell within values
reported by Wanielista et al. (1977) for storm water data, except for ammonium
levels (x = 0.02 mg N/L), which were well below the typical values. Site 5
exhibited the highest concentrations of all nitrogen species, with ammonium-N,
nitrite plus nitrate-N, and TKN averaging 0.24 mg/L, 0.83 mg/L and 1.23 mg/L,
respectively. This trend is to be expected, since site 5 lies downstream of
a wastewater treatment plant effluent on Possum Creek. The swampy area upstream
of site 2 may have been partially responsible for the lower levels of nitrogen
observed at that site, although the levels remained somewhat high, especially
nitrite plus nitrate-N (0.55 mg/L). This level is similar to the average con-
centration of this parameter (0.48 mg/L) in urban stormwater runoff from south
Florida (Mattraw and Sherwood, 1977). Temporal variations for NO plus NO2-N
and TKN over the 15 week sampling period are presented in Figure VII-4 and
VII-5, respectively, and show a high variation for both parameters at sites
2 and 5, and for TKN at site 4. Nitrate plus nitrite had the highest overall
correlation of the measured nitrogen species with flow, but even in this case,
flow variations explained only a small fraction of the variance in concentration
(r = 0,22).

Mass loadings were calculated for the nitrogen species at the three
weekly sample sites. Values for total Kjeldahl nitrogen, nitrate + nitrite
and ammonium nitrogen are illustrated in Figures VII-6, VII-7 and VII-8
respectively. The high flow during week 9 contributed significantly to the
mass loading rates of all species. Site 2 also had a conspicuous peak for
nitrate + nitrite loading during week 11, due to a relatively high flow and
a moderately high concentration. These figures give an indication of the
effect of localized storms in the Hogtown Creek drainage basin on downstream
loadings of the various nitrogen species. On a relative basis, the rain event
during week 9 had a greater impact on loading of TKN (Figure VII-6) than on
either ammonium or nitrate + nitrite loadings. A period of approximately
one month of negligible rainfall (Figure V-3) preceded the event of April 2-3
(week 9), which enabled a typical "first flush" rainfall event to occur. In-
soluble nitrogen (TKN) exhibited a large peak in mass loading at that time,
and a smaller peak occurred two weeks later following another rain event.
Insoluble organic material did not have as much time to accumulate in the
watershed prior to the occurrence of the second storm. Soluble nitrogen
(nitrate plus nitrite) was not influenced by the variations in storm intervals.
Ammonium concentrations were near detection limits during the second event.

Total phosphorus levels at the three weekly sampling sites ranged from
an average concentration of 1.08 mg/L at site 2 to 2.17 mg/L at site 5.
These values are high compared to TP concentrations reported by Odum (1952)
for small humic-colored creeks ( 0.41 mg/L) in Florida, and they even are
slightly higher than the levels he reported for streams not draining phosphate
formations but receiving sewage (0.84 mg/L). However, Odum (1952) also reported
TP concentrations for sites in Hogtown Creek that are analogous to sites 2, 4,
and 5 in this study, and his results (1.4, >1.0, and >2.0 mg/L, respectively)
are similar to levels found in this report (Table VII-2). Thus in terms of

















2.0 -






O 1.0









0 I 2 3 4 5 6 7 8 9 10 II
WEEK OF EVENT


12 13 14 15


Figure VII-4 Nitrate + Nitrite vs. Weekly Sample Period
















--. SITE 2
0--o SITE 4
-- SITE 5


0 .0 i 1i -- -- -i
0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15

WEEK OF EVENT


Figure VII-5 TKN vs Weekly Smaple Period


A 3.9


2.0

-J

E

2
H -
1--^



























































I 2 3 4 5 6 7 8 9 10 11 12 13 14 15


WEEK OF EVENT




Figure VII-6 TKN load vs. Weekly Sampling Period


i-


- 60



Z ,
LU 50
0


Z 40
-J



L 30


-2
I-- 20
0
!-


2Z
8.2 "






























z





z 5






Li 3


H 2
z


I 2 3 4 5 6 7 8


z
27 00
1
z
0
2.3 N



1.8


9 10 II 12 13 14 15


WEEK OF EVENT

Figure VII-7 Nitrate+Nitrite load vs. Weekly Sampling Period
































































I 2 3 4 5 6 7 8 9 10 II


WEEK OF EVENT


Figure VII-8 Ammonia load vs. Weekly Sampling Period


z



O I
_-


z
I

:-

La


12 13 14 15










TP, cultural disturbance in the watershed seems not to have worsened since
1952. Average levels of soluble reactive phosphorus (SRP) ranged from 0.46
(mg/L) at site 4 to 1.23 (mg/L) at site 5. Concentrations of both SRP and
TP were consistently highest at site 5 (with one exception in each case)
over the 15 weeks of routine sampling (Figures VII-9 and VII-10), and site
4 generally had the lowest concentrations of both species. Arguments sup-
porting these trends are analogous to those for nitrogen; site 5 is down-
stream of a domestic wastewater discharge and little opportunity exists for
natural treatment processes to remove phosphorus between the discharge point
and site 5.

Mass loading calculations (Figures VII-11 and VII-12) indicate that a
storm event following a period of no rainfall affects TP more than SRP. This
trend follows the trends noted for the nitrogen species. 2However, little
overall correlation of phosphorus with flow is evident (r (SRP) = 0.12,
r (TP) = 0.15).

Biological Parameters. Chlorophyll a levels measured in-stream rarely
rose above 2.0 mg/m Site 5,had the lowest average (0.7 mg/m ), while site
2 averaged a high of 1.5 mg/m It is obvious, both from these data and from
visual inspection of Hogtown Creek, that planktonic productivity is low in the
stream. Moreover, the general absence of macrophytic vegetation in the
stream indicates that overall the stream has low autotrophic potential and
that it functions as a heterotrophic ecosystem. The levels of chlorophyll in
the stream are not surprising, given the short hydraulic residence time of the
stream. Furthermore, Hogtown Creek is predominately shaded and colored, thus
hindering the growth of algae, even on sediments where they otherwise would
most likely be found.

Total coliform levels during the weekly sampling program often exceeded
the State of Florida Class III water quality standard of 2400 colonies/100 mL
at all three sites. Nearly 60% of all measured values exceeded the standard,
and sites 2 and 4 exceeded the standard for 70% and 90% of the samples taken,
respectively. However, TC levels at site 5 were above the standard only
about 20% of the time. Chlorination of the wastewater effluent above site
5 could have led to the lower values found at that site; general (overall)
conditions of the watershed probably are better represented by data collected
at sites 2 and 4. The simple (arithmetic) average levels of TC were similar
at the three sites (about 3.2 x 10 colonies/100 mL), but the high standard
deviation (6.5 x 10 ) indicates a highly skewed distribution and severe
contamination in some samples. Geometric means are better indicators of
central tendency in skewed populations; these means for TC at the three sites
are 4175, 8575 and 1163 colonies/100 mL for sites 2, 4 and 5 respectively.
2
Little correlation was observed between TC levels and flow (r < 0205)
or other physical parameters, such as temperature (r = 0.10) and pH (r < 0.05).

The Class III standard for fecal coliform (800 colonies/100 mL) was ex-
ceeded in over half of the samples taken in the weekly study. Site 4 exceeded
the standard in all of its samples and.had fecal coliform to fecal streptococcus
(FC/FS) ratios above 4.0 in over 80% of the samples. Sites 2 had the fecal
coliform levels above the Class III standard about 30% of the time and it had
an FC/FS ratio above 4.0 one third of the time; surprisingly, the FC/FS ratio
for site 5 was below 4.0 for all samples (in spite of the fact that this

















.-.. SITE 2
o--o SITE 4
- SITE 5


1 2 3 4 5 6 7 8 9 10 II 12 13 14
WEEK OF EVENT


Figure VII-9 SRP vs. Weekly Sampling Period


S1.0

0


0.0
0

















4.89!
5.11 04.15


,---- SITE 2
o-- SITE 4
-- SITE 5


I 2 3 4


I I I I I I


5 6 7 8 9 10 11 12 13 14 15


WEEK OF EVENT


Figure VII-10 Total Phosphorus vs. Weekly Sample Period


2.0 k


o 1,0
CL


0.00
































o
-Q

CL
0





O
0
0L
0
F-
0


WEEK OF EVENT


SRP Load vs. Weekly Sample Period


Figure VII-11






































. 25
a-

I-


g 20
0
a-
0
a-p
15
O.
0
i--


I 2 5 4 5 6 7 8 9 10 II 12 13 14 15


WEEK OF EVENT



Figure VII-12 Total Phosphorus Load vs. Weekly Sample Period









was the closest site to the sewage effluent discharge point). The fecal
coliform to fecal streptoccous ratio (FC/FS) can be used to indicate the
source of fecal contamination (Burdner and Winter 1978), with-ratios above
4.0 being predominately human in nature and those below 1.0 indicative of
agricultural sources. Values between 1.0 and 4.0 are indicative of mixed
sources. Neither fecal coliform (r < 0.05) or fecal streptococcus
(r = 0.13) levels correlated significantly with flow.

Overall, two separate areas seem to exist in the Hogtown Creek water-
shed in terms of coliform levels. Possum Creek (site 5) exhibits almost ac-
ceptable total coliform levels, with the apparent source of fecal contamina-
tion being predominantly non-human in nature. The main branch of Hogtown
Creek, however, (site 4) shows very high total coliform levels, with fecal
contamination primarily of human origin. Coliform levels at site 2 were in
an intermediate range, reflecting the mixing of the two branches upstream.
It is likely that chlorination of the domestic waste effluent above site 5
led to a depressed level of fecal contamination there; reasons for the high
levels of coliforms at site 4 are not immediately obvious. A further sampling
program is needed to establish the source of this contamination.


Statistical Analysis of Weekly Sampling Data. A brief statistical analy-
sis was conducted on the weekly sampling data for the three stream stations
using the Statistical Analysis System (SAS) program. One-way Analysis of
variance and Duncan multiple range tests were used to determine whether
statistically significant differences exist in mean values for selected
variables among the three sites (2, 4 and 5) in weekly sampling program.
The Duncan test was used for TKN, T-P, flow, turbidity, BOD, TOC, suspended
solids and color. Of these parameters, only two (flow and TOC) had
statistically different values (Table VII-3). As expected, flow was higher
at site 2, downstream from both sites 4 and 5. TOC was statistically higher
at sites 2 and 4, and the cause of this probably is a TOC source upstream
on the main branch of Hogtown Creek.


Weekly Sampling of Detention Basins

Two detention basins were sampled weekly, sites Dl and D4 (Figure 11-4).
Site D4 is located between a cluster of residential homes, and serves as the
in-stream detention basin. Eleven samples were collected from this site at its
effluent end. Inflow is from a small tributary that eventually enters the main
stream of Hogtown Creek below site number 2. Site Dl is an off-stream detention
basin which serves as a rainfall catchment for a small subdivision and empties
into Possum Creek downstream of site 12. Six samples were obtained from this
site; for the majority of the study period no flow was observed from this
basin. Four of the samples were taken during high flow conditions, and
two samples were taken under low-flow (background) conditions early in the
study. The limited number of samples collected at site Dl, and the low-flow
conditions under which two of the samples were taken make a thorough analysis
of data for this site speculative. Flows were not measured at either site
as part of this project.


Physical parameters. Overall, the detention basins exhibited better
water quality than the in-stream stations. Temperatures were somewhat higher









TABLE VII-3 Duncan Multiple Range Test For Selected Varibles


Parameter

TKN (mg/1)





Total-Phos. (mg/I)





Flow (cfs)





Turbidity (JTU)





BOD5 (mg/1)





TOC (mg/1)





Suspended Solids (mg/1)





Color (units)


Site


Mean

1.233
0.935
0.916


1.769
1.308
1.076


46.62
14.58
8.34

10.09
9.76
9.53

2.553
2.444
2.365


32.52
29.16
22.23


11.28
10.85
10.45

202.2
171.2
134.2


Alpha Level = 0.05
Means with same letter are not significantly different.


N


Grouping










in the basins, reflecting large surface area to volume ratios. Dissolved
oxygen levels were substantially lower in the basins than in the stream, in
part reflecting the temperature difference and semi-stagnation at times at
site Dl. Dissolved oxygen levels at sites D4 and Dl averaged 7.0 mg/L and
4.7 mg/L, respectively. A minimum of 3.2 mg/L was measured at site Dl on
March 11, 1980. Site Dl did not meet the Class III water quality standard
of 5.0 mg/L on five of the six sampling dates.

The pH of the two detention basins fell below the Class III standard of
6.0 once, (D4 = 5.9, D1 = 5.2) on February 27, 1980, but there is no evidence
that this variance is a result of cultural activity. The average pH at the
detention basins was 6.5 (Dl) and 7.6 (D4).

The bottom was visible on all sampling dates in the detention basins, and
hence Secchi disk transparency could not be measured. Lower turbidity and
suspended solids data for the detention basins compared to the stream sites
indicate that the basins do operate as settling areas for particulate matter.
Turbidity averaged 2.8 NTU (DI) and 1.9 NTU (D4) for the detention basins, while
the three in-stream sites averaged 9.8 NTU. If the three in-stream samples can
be equated to general in-stream water quality, these results are equivalent
to a removal of 70-80% of the turbidity in the detention basins. Suspended
solids concentrations averaged 3.6 mg/L at Dl and 3.4 mg/L at D4. The three
in-stream samples averaged 10.9 mg/L, which also is equivalent to about 70%
removal of suspended solids for the detention sites.

Color averaged 50 CPU at both detention basins, which is significantly
lower than the average of 170 CPU observed at the three in-stream sites.
Conductivity correlated well with alkalinity (r = 0.81) at site D4, which is
analogous to correlations discussed earlier for the in-stream samples. An
insufficient number of data points are available for site Dl for meaningful
statistical analysis. Conductivity at Site D4 averaged 187 pmho/cm and Dl
averaged 157 pmho/cm; these values are comparable to the average of 170 pmho/cm
at the three in-stream sites.


Major Ions. Average anion and cation concentrations for the detention
basins were near or below the average of the three in-stream sites. Alkalinity
sulfate, chloride, sodium and calcium levels at site D4 were approximately the
same as the average in-stream values, whereas all major ions had lower average
concentrations at site Dl. Average values are listed at the end of Appendix E
for the individual sites. As in the stream samples, calcium and alkalinity
were the dominant ions (30 mg/L of Ca and 55 mg/L (as CaCO3) of alkalinity
for both Dl and D4).


Organic Matter. Average levels of biochemical oxygen demand (BOD) at
basin D4 were similar to those measured in-stream (2.4 mg/L), while basin
Dl had a slightly higher2average (3.0 mg/L). BOD correlated significantly
with color at site D4 (r = 0.79), which follows the trend discussed earlier
for the in-stream samples. Total organic carbon (TOC) levels in the deten-
tion basins were approximately 50% lower than those reported for in-stream
samples (D4 = 14.8 mg/L, Dl = 15.6 mg/L). This can be related partly to the
settling of suspended particulates in the quiescent water column and partly
to the reduced color levels found for the detention basin samples. BOD and










TOC did not directly correlate at site D4 (r2 < 0.01); the small number of
samples available for site DI precludes meaningful correlation analysis for
that site.


Nutrients. Nitrogen and phosphorus concentrations in the detention
basins were generally lower than those encountered in-stream. Total Kjeldahl
nitrogen (including particulate nitrogen) was lower by averages of 22% and
40% at sites D1 and D4, respectively. This can be attributed to settling.
However, dissolved nitrogen species, such as ammonium, nitrite and nitrite
plus nitrate also were lower. TP and SRP concentrations exhibited similar
characteristics. TP was 45% (Dl) and 72% (D4) lower than in the in-stream
samples. In all cases, nutrient concentrations were lower at basin D4 than
at Dl. This could be due to a large standing crop of macrophytes in basin
D4, which probably was actively assimilating nutrients.


Biological Parameters. Chlorophyll a levels in the two detention basins
averaged 4.7 mg/m at Dl and 1.75 mg/m at D4. These values are well below
the level associated with eutrophic conditions (10 mg/m ) in lakes.

Total coliform levels for two samples at basin Dl1 (geometric mean = 6700
colonies/100 mL) were well above the state standard for single samples (2400
colonies/100 mL). Basin D4 had total coliform levels above the standard
(geometric mean = 2650 colonies/100 mL). Fecal coliform levels for 8 samples
collected at basin D4 had a geometric mean of 172 colonies/100 mL, well below
the Class III standard of 800 colonies/100 mL). One fecal coliform sample
collected at basin Dl indicated a high level of contamination (1480 colonies/
100 mL). The source of contamination at basin D4 appeared mixed in that FC/FS
ratios ranged from 0.008 to 5.8; the single FC/FS measurement at site Dl
(FC/FS = 18.0) indicated contamination from human waste. Overall, the biological
quality at basin D4 was acceptable or near-acceptable, but based on the limited
number of samples at basin Dl, this site appears to be highly polluted.


Summary of Weekly Sampling

The water chemistry in Hogtown Creek is not what one would call descrip-
tive of a creek in a "pristine" condition. Levels of turbidity and phosphorus
discussed earlier compare the water quality closer to urban stormwater runoff
than to naturally occurring stream flow. This must be expected, in light of
the development of commercial and residential areas in the watershed. A
contribution of domestically related parameters, such as nutrients, cations
and solids, along with the contribution of commercially related organic, color
and turbidity is evidenced by the weekly sampling portion of this study.
Further monitoring of the water chemistry of Hogtown should be done, with the
addition of water quality data in the form of parameters such as oil and grease,
heavy metals and specific organic, in short, the Class III State Standards.
Following this, more accurate information of the point sources can be evaluated
and preventive action can take place.









Surface Water Synoptic Sampling


Two comprehensive (synoptic) surveys of Hogtown Creek were undertaken
during the study to obtain detailed information on spatial variations in
stream water quality under both low-flow and high-flow conditions. A total
of 15 in-stream and detention basin sites (Figure VI-1) were sampled within
a 6 hour period on April 3, 1980, immediately following a 5 cm (2 in) rain-
fall event. These sites were chosen according to the relative proximity of
possible point source (storm drain) discharges. The same sites were sampled
again on May 6, 1980, during low flow conditions that followed a two week
period of no rainfall. Thus the two sampling events can be equated to a
rainfall event analysis versus background data. The relative flow measure-
ments of the two periods on the average differ by greater than a factor of ten in
magnitude- Water quality conditions during the two surveys provide some in-
teresting comparisons of flow-related trends. These trends and spatial trends
along the stream comprise the majority of the following discussion. All data
are presented in Appendix E.


Physical Parameters. Flow measured at sites 4 and 5 contributed almost
80% of the total flow measured at site 2 for the low flow event, but only 45%
during the high flow. This difference reflects the effects of the low lying
area (swamp) above site 2. Water temperatures averaged 22C for both synoptic
surveys. Detention basin D4 maintained a slightly higher than average tempera-
ture on both dates (26C), and site 1 was higher during the high flow sampling
(28C). Hogtown Creek at site I overflowed its banks during high flow, which
resulted in a large surface area to volume ratio at that time, causing a
slightly elevated temperature. Relatively little variance in pH was noted for
the 15 sites during either sampling period, and the range in individual values
was one pH unit (6.7 to 7.7), except for a single higher value (8.4) at site
D4 during high flow.

Dissolved oxygen (D.O.) levels fell below the State Class III standard
for the in-stream samples only at sites 14 (4.7 mg/L) and 17 (4.4 mg/L) during
the low flow sampling. Site 14 is directly downstream of a known phenolic
contributor on the main stem of Hogtown Creek (Figure IV-1), while site 10 is
directly downstream of a domestic wastewater treatment plant effluent. Dilution
of these samples with runoff could easily have masked low D.O. levels during
the high flow event. Detention basin Dl had a low D.O. during the high flow
event (3.7 mg/L).

The average suspended solids levels varied by a factor of 2.6 for samples
collected on the separate dates. The high flow event averaged 21.2 mg/L, while
baseline, (low flow) measurements averaged 8.2 mg/L. Spatial variations were
somewhat inconsistent for the two periods (Figures VII-13 and VII-14), but sus-
pended solids levels generally decreased with distance downstream.
Turbidity measurements also were substantially higher during high flow
(x = 21.6 NTU) than during low flow (x = 10.6 NTU). Variations downstream during
high flow indicated few trends (Figure VII-15), except for lower turbidity
levels in the far downstream samples. Baseline measurements were generally uniform
downstream, but samples collected along Possum Creek were slightly higher








































2 5 D4 4 DI 6 12 19


SAMPLE


STATION NUMBERS GOING UPSTREAM


Figure VII-13 Suspended Solids vs. Distance Upstream-
High Flow Sampling 4/3/80


Distance between stations not to scale.




















-J

E

U)

Cr720


0
CO



S10
CO


1 17 2


SAMPLE


5 D4 4 DI 6


1219 II 1610 14


STATION NUMBERS GOING UPSTREAM


Figure VII-14 Suspended Solids vs. Distance Upstream-
Low Flow Sampling 5/14/80

Distance between stations not to scale.




















4/3/80

HOGTOWN
POSSUM
TRIBUTARIES


/ ~N
/ -4
/


N


N,
N,
N.
N


IN.

1 "> I 1 I I1


I I I I


I 17 2 5 D44 DI 6 12 19 II 1610 14 9

SAMPLE STATION NUMBERS GOING UPSTREAM


Figure VII-15


Turbidity vs. Distance Upstream-
High Flow Sampling 4/3/80
Distance between stations not to scale.









than those along the main stream (Figure VII-16). Turbidity at site 14
was significantly higher than that at the other sites during low flow.
In both synoptics, the detention basins (D4 and DI) had relatively low
suspended solid and turbidity levels, as would be expected. Visibility
was restricted during the storm-related sampling and the bottom was
obscured at many sites for the only time during the enitre study.
Visibility averaged less than 8 in. (20 cm.) for the sites where the
bottom was not visible. The turbidity and suspended solids during this
time give an indication of the degree of wash-off from the adjacent
watershed.

The average level of color was almost three times higher during the
high flow synoptic (370 CPU) than during flow (135 CPU). In both surveys
site 14 exhibited the highest color level. Dilution effects can be seen
for color (Figures VII-17 and VII-18), where flow from other tributaries
lowered the color levels with distance downstream from site 14. The
fact that this trend occurred during both low and high flow periods
suggests a non-flow related contribution of color above site 14. In
both synoptics, color measurements along the main branch of Hogtown
Creek were higher than those for Possum Creek, which further substantiates
the presence of a point source on the main stream.

Major Ions. The major cations (Ca, Mg, Na, K) and anions (HCO ,
2- 31
SO, Cl ) were generally lower in concentration during the high flow
synoptic than during the low flow. Conductivity, a general measurement
of ionic strength, was much lower during the high-flow sampling, averaging
130 pmho/cm in the latter survey and 210 pmho/cm in the former. This
trend may be attributed to lower dissolved solids levels in rainfall and
sheet-flow accompanying the high flow conditions. The low flow synoptic
yielded higher conductivity levels than the overall study average (170
pmho/cm), although in general all major ions (except alkalinity) were
near their averages for the entire study.

Nutrients. During baseline flow, high levels of nitrogen and
phosphorus were evident along Possum Creek, beginning at site 10.
Concentrations of ammonium (0.5 mg/L), nitrate (0.25 mg/L), and SRP (1.7
mg/L) were especially high at site 10, (downstream of a wastewater
treatment plant effluent). Concentrations of these species generally
decreased with distance downstream. Similar conditions were not in
evidence during the high flow period. Dilution of the treated wastewater
with run-off caused this effect. In general, higher concentrations of
dissolved inorganic nitrogen and SRP were evident during the low-flow
period than during high flow. Organic forms of nutrients (TKN minus
NH3, TP minus SRP) generally were higher during the rainfall associated
synoptic, due to washoff of terrestrial organic detritus (litter).
Average levels of organic nitrogen (1.02 mg/L) and organic phosphorus
(0.45 mg/L) during high flow, however, were only slightly higher than
the overall average for the study (TON = 0.81 mg/L, org P = 0.41 mg/L).
Low flow TON averaged 0.60 mg/L and org P averaged 0.37 mg/L.

Organic matter. Biochemical oxygen demand (BOD) measurements made
during the second synoptic (low-flow conditions) indicated rather uniform
concentrations with distance downstream (Figure VII-19) except for two


















5/14/80

HOGTOWN
--- POSSUM
TRIBUTARIES


I 17 2 5 D4 4 DI 6 1219 11 161014 9

SAMPLE STATION NUMBERS GOING UPSTREAM

Figure VII-16 Turbidity vs. Distance Upstream-
Low Flow Sampling 5/14/80

Distance between stations not to scale.


















4/3/8C

-- I


HOGTOWN / .
POSSUM
TRIBUTARIES \

/ p


S/"
-/ /

-\ //
!^]


700

630

560

490

420

350

280

210

140

70

0


/
/
/
/
/


I I I


I 17 2 5 D44 Di 6 1219 II1 16 1014 9
SAMPLE STATION NUMBERS GOING UPSTREAM

Figure VII-17 Color vs. Distance Upstream-
High Flow Sampling 4/3/80

Distance between stations not to scale.


I I I I






















5/14/80


--- HOGTOWN
-- POSSUM
TRIBUTARIES


/

N
N
N
N 7 \
K.
N. *-. N*


N
N
N


41 II I I I h

f 17 2 5 044 6 1219 II 161014 9

SAMPLE STATION NUMBERS GOING UPSTREAM


Figure VII-18


Color vs. Distance Upstream-
Low Flow Sampling 5/14/80

Distance between stations not to scale.


500 1-


400 1


3500 -


200 I-


100 -




















5/14/80


--HOGTOWN
---POSSUM
--- TRIBUTARIES


E


Cu







LLJ



x
0


I t I I I I l


I 17 2 5 D4 4 6 1219 II 161014 9

SAMPLE STATION NUMBERS GOING UPSTREAM

Figure VII-19 BOD5 vs. Distance Upstream-
Low Flow Sampling 5/14/80


Distance between stations not to scale.


63 -

5.6 -

4.9 -


I \
I
~L~* \

"S


I t









sites. The elevated BOD concentration at site 10 (5.5 mg/L) may have
been the result of insufficient chlorination at the wastewater treatment
plant, while an elevated BOD level at site 14 could have been the result
of organic contributed upstream of that site. The detention basins had
higher BOD levels (19 mg/L) than the remainder of the stream (average of
1.0 mg/L excluding sites 10 and 14) for the low flow synoptic. Total
organic carbon (TOC) concentrations during high flow.were higher (average
of 27.6 mg/L) than during low flow (average of 21.8 mg/L), again to
reflecting runoff of detritus associated with the rainfall event.
Spatial variations with distance downstream (Figures VII-20 and VII-21)
indicate that Possum Creek had a much lower level of TOC during both
synoptics than did the main stream. Runoff contributed to a high TOC
level at site 16 during the April synoptic (site 14 not reported), while
the maximum TOC concentration in the low-flow (May) synoptic was measured
at site 14. Lower TOC levels were observed during both synoptics in the
detention basins (x = 12.8 mg/L) than for the in-stream samples. Along
with the color results, the results on TOC indicate the presence of
organic contamination above site 14, both as colored and non-colored
dissolved organic.


Biological Parameters. Total coliforms levels were extremely
elevated (geometric mean = 12,000 colonies/100 ml) during the high flow
synotpic, as were fecal coliform levels (geometric mean = 3300 colonies/100
ml). Wash-off of detritus contributed to these elevated levels, and a
prior a mixed source of animal and human contributors might be expected.
Slightly more than half of the samples had FC/FS ratios below 4.0.
Water quality was much better in terms of biological activity during the
low flow synoptic. Although the geometric mean (2600 colonies/100 mL)
for total coliforms was above the State Class III standard, only three
of the 14 individual samples collected exceeded the standard. Fecal
coliforms averaged higher than the State standard (geometric mean = 1100
colonies/100 ml), and FC/FS ratios were indicative of human waste (greater
than 4.0) in slightly over half of the samples.

Cluster Analysis of Synoptic Data. A multivariate statistical
procedure, cluster analysis, was used to group the 15 synoptic stations
according to their chemical similarity based on six common water quality
parameters. The SAS routine, CLUSTER was used for this purpose and the
parameter values used were the averages of the two synoptic samples at
each site. Parameters used in the cluster analysis were TKN, T-P, TOC,
Chlorophyll-a, turbidity and color. The highest degree of similarity
occurred between the two detention basins, (Dl and D4), and the far
downstream sites (1 and 17) also were clustered together at a high
degree of similarity. Site 14 showed the least degree of similarity
with any other site, (Figure VII-22). This finding is interesting in
the light of the various observations of pollutant input above site 14
noted earlier in this report, and indicates unique conditions at that
site compared to the rest of the watershed.






















-- HOGTOWN
~ POSSUM
. TRIBUTARIES


p
/
/

/ / ----

~- /
--F,


2 5 D44DI 61219


II 1610


SAMPLE STATION NUMBERS GOING UPSTREAM

Figure VII-20 TOC vs. Distance Upstream-
High Flow Sampling 4/3/80
Distance between stations not to scale.


70 )-


E
-56

H49
z"
042
m





Cr"
0
14

-J
V7
V_

























--- HOGTOWN
--- POSSUM
TRIBUTARIES


5 D44DI 6 12 19


SAMPLE


STATION


NUMBERS GOING UPSTREAM


Figure VII-21 TOC vs. Distance Upstream-
Low. Flow Sampling 5/14/80


Distance between stations not to scale.


45 L

40


301-


15 V


~~4,


1 1 I I l l i


1 I I I I


II 160 14


I I I I I I I I I I


I








Site Degree of Similarity
2
il
8 -i
5-
6
16
4 ----------
9

14
D4 -

Dl
1-
17
12

Figure VII-22 Cluster Analysis of 15 sites. Parameters TKN,
CHL A, T-P, TURB, TOC, COLOR.


Summary of Synoptic Studies

Higher flow during the first synoptic (April 3, 1980), which followed
a rain event, resulted in higher levels of parameters associated with
particulate matter (TKN, turbidity) than during the low-flow event (May
6, 1980). Of the 15 sampling sites, station 14, below a suspected
phenolic waste contributor, registered the poorest water quality in
terms of dissolved c : :i (D.O.), suspended solids, color, turbidity,
biochemical oxygen demand (BOD5) and total organic carbon. Poor water
quality in terms of nutrient enrichment and high levels of BOD were
evident at site 10, but decreased with distance downstream. This trend
reflects the presence of a wastewater treatment plant effluent above
site 10.

In general, the main branch of Hogtown Creek exhibited poorer water
quality than did Possum Creek. Somewhat different land uses in the two
watersheds may contribute to the differences in water quality. The
watershed of Possum Creek is comprised mainly of suburban homesites,
with some undeveloped wetlands and forest, and some unspoiled sections
of creekbed. The main branch of Hogtown Creek runs through sections of
commercialized land and is generally more intensely developed. In both
tributaries, water quality becomes better with increasing distance
downstream from the aforementioned sources.

Water Quality in Hogtown Creek during a Storm Event

A rainfall event was sampled during 22-23 January, 1980 at site 2.
The sampling occurred before, during and after a 3.18 cm (1.25 in)
rainfall, for the evaluation of both baseline data and influence of
storm.water runoff on the receiving water quality. Measured parameters
included flow, TKN, NO 3 + NO ortho-P, Ca, Mg, K, Na, Cl, conductivity,
pH, turbidity, and dissolved inorganic and organic carbon. Because
samples were collected with an automated sampler, the effects of the









runoff on some significant parameters such as dissolved oxygen and BOD
could not be discerned. A storm hydrograph and concentration versus
time plots for important water quality parameters are shown in Figures
VII-23 to VII-27. Samples were collected hourly for a 28 hour time
period by an automated Isco model 1600 sampler, and flow was determined
with an Isco Model 1700 flow meter and recorder.

Peak flow occurred 7-9 hr. after initial rainfall (Figure VII-23)
and reflected two separate periods of intense rainfall. A ten day dry
period preceding the rain event helped to establish baseline conditions
in the stream. Parameters reflecting suspended solids, such as TKN and
turbidity (Figure VII-24), increased in concentration as flow increased.
This is to be expected, because of the lower settling velocities of
particulate matter in faster moving streams. Wash-off of loose debris
also would contribute to an increase in suspended solids during a rain
event. On the other hand, the concentrations of most dissolved species
(NO + NO, ortho-P, dissolved carbon, Ca, Mg, Na, and Cl), as well as
specific conductivity, decreased as flow increased (Figures VII-25 and
VII-27). This trend reflects the diluting effect of rainwater on dissolved
species in the streamflow. In spite of the decreases in concentrations,
loading rates (concentration times flow) increased for all measured
constituents during the period of storm runoff.

First flush effects were noted for TKN, NO-3 + NO2 orthophosphate
(SRP) and TOC, and the effect was particularly striking for TKN (Figure
VII-23). Baseline concentrations of SRP were high, and throughout the
event, levels of SRPJ were consistently greater than combined levels of
the inorganic nitrogen forms. Nitrogen thus would be the limiting
nutrient for plant growth under favorable conditions.

The stormwater event data are in general agreement with data
collected in other urban areas of Florida. Results for selected parameters
(turbidity, TKN, NHd-N, NO, + NO SRP and specific conductivity) are
compared to reDortea data from three other studies in Table VII-4. The
considerable ranges encountered for most parameters during runoff events
complicates comparison of the several studies. In general, it appears
that Hogtown Creek had low concentrations of inorganic nitrogen and high
concentrations of SRP, compared to other sites in Florida.

Sediment Studies

Physical and Chemical Characteristics. Sediment analysis was
conducted on ten samples in Hogtown Creek. Results (Table VII-5) showed
the samples to be composed mainly of sand, except for that from site 6
(Figure VI-1), which was approximately 50% sand and 50% gravel. The
organic content of the sediments was low for all ten sites, with maximum
values of 7.2% (as volatile solids) at site 6 and 4.6% at site 19. The
remaining sites contained less than 1.0% volatile solids.

Total phosphorus levels in the sediments averaged 2.2 mg/g, with a
high of 7.0 mg/g at site 6, and low of 0.15 mg/g at site 10. TKN values
were low, reflecting the low organic content, and averaged 0.047 mg/g,
with a maximum at site 5 (0.075 mg/g). Nitrate plus nitrite levels also
were low at all ten sites, with a maximum value of 0.022 mg/g recorded



















RAIN RAIN 0

-200


15 0
:D






I50








i FLOW
CONDUCTIVITY


6pm 12am 6am 12pm 6pm
JAN. 22 JAN. 23


TIME, hours


Figure VII-23


Storm Hydrograph and Conductivity Levels,
Single Rain Event, January 22-23, 1980


0

.-2.
C'-
0

ii



















700 E

600 > J
"- .
5o0 0 0
>- 0
400 I-
C Z
300 m Ld

200 -

100 2


6pm 12am 6am' 12pm 6pm
H JAN. 22 -- JAN. 23

TIME, hours


6pm 12am 6am 12pm 6pm
- JAN. 22 JAN. 23

TIME, hours


Figure VII-24


TKN and Turbidity vs.
Time, Single Storm
Event


Figure VII-25 Soluble Nutrient
Concentration vs. Time,
Single Storm Event


ZZ
C;4
E

z
H%


* NH,4 -N
SN03--N
* SRP














rn-i
45

E 40


35


_J

36

() 32
28
0
LL.
24

0 20
CO
4 16



0
(J.
o-

C.)


12pm 6pm 12am 6am 12pm 6pm
JAN. 22 JAN. 23 "-

TIME, hours


Ca
Cl
a Na
o Mg
AK



S -- ----/

/.


o0-
12pm
h-


6pm 12am 6am 12pm 6pm
JAN. 22- JAN. 23

TIME, hours


Figure VII-26


Concentrations of Major
Ions vs. Time, Single
Storm Event


Figure VII-27 Concentrations of Carbon
Forms vs. Time, Single
Storm Event.


&TDC
*DIC
o DOC









Table VII-4 Characteristics of Stormwater from Florida Sites


Constituent
(mg/L Unless
Specified)


Turbidity (NTU)


NO3+NO2-N

NH -N
4


00 Conductivity
(pmho/cm at 25 C)


Broward County
Residential Area


Mean


12.8


Range


3.0-7.0


0.535 0-3.6

0.343 0.01-2.6

0.218 0.03-0.18

98.9 5.5-350


Orlando2
Commercial


Orlando2
Residential


Area Area
Range Range


0.3-34


0.07-3.87

0.J11-1.33


0.12-0.47


359-377


Alachua County3
Forested Area
Weighted Means
1975-6 1976--7


Hogtown Ck.
This Study
Range


0.9-24


0.02-1,,96

0.03-0.58


0.01-0.20


2.59

0.26*


0.51


5.1-700

0.5-3.15


1.77

0.09


0.07-0.41

0.019-0.054

0.27-0.64


0.51


208-251


100-180


*NO3-N only


1Mattraw and Sherwood (1977). Study included
residential area in Pompano Beach, Fla.


2
Wanielista, et al.


samples from 30 runoff events in a 19 hectare single-family


(1977). Study included samples from two storm events in Orlando, Fla.


3Campbell (1979). Data shown are weighted mean concentrations for stormflow events throughout the year in
a 437 hectare watershed composed of forest (63%), unimproved pasture (8%) and cropland (29%).










Table VII-5 Sediment Analysis Results


% % % mg/g
Gravel Sand Clay Total-P (P)


0.4

0.3

0.7

0.1

45.8

4.2

2.2

1.3

0.9

1.0


96.2

98.8

97.7

99.3

53.6

93.5

96.4

98.4

98.2

98.0


3. 4

0.9

1.6

0.6

0.6

2.3

1.4

0.3

0.9

1.0


5.32

2.63

2.33

2.59

7.03

0.40

0.15

1.31

0.16

0.50


%
Volatile
Solids


mg/g mg/g
TKN (N) NO 3-NO2

.055 .002

.041 .003

.053 .011

.075 .022

.028 .007

.033 .002

.048 .007

.036 .012

.048 .005

.054 .014


Sample


mg/g lg/g
(N) Pb Fe

0.04 0.71

0.05 0.47

0.08 0.37

0.05 0.38

0.05 2.67

0.03 0.51

0.10 0.90

0.03 0.41

0.02 0.46

0.03 0.66


0.4

0.0

0.5

0.3

7.0

0.3

0.6

4.6

0.7

0.3










at site 5. Although site 10 was directly downstream of the discharge
point for a wastewater effluent, it had the lowest total phosphorus
level of all samples and an average nitrogen level, thus indicating that
the effluent has no significant impact on the stream sediments.

The sediments contained trace quantities of lead (Pb) with a maximum
value of 0.10 mg/g at site 10. Total iron concentrations ranged from a
low of 0.41 ug/g at site 19 to a high of 2.67 Vg/g at site 6. Site 6 is
located upstream of an intersection with a roadway. Sites 22 and 19 are
above and below a Mall, respectively but no impact of this land use can
be seen in the lead results. In summary, the chemical analyses performed
on sediments from Hogtown Creek indicate that organic matter and lead
levels a.e low, and the sediments consist primarily of uncontaminated
sand.


Benthic Invertebrates. Benthic invetebrates are useful as indicators
of water quality conditions and environmental stress. Because of their
relatively sedentary nature and extended life cycles, they are not able
to escape periodic episodes of pollution, and thus they reflect the
integrated conditions of water quality over a relatively long period of
time. Benthic invertebrates are important to the ecology of streams and
aid in the breakdown of detrital material. Many invertebrate groups
such as amphipods and oligochaetes are also important sources of food
for certain fish species. A knowledge of the environmental requirements
of specific species of benthic invertebrates found in an area can be
useful in assessing water quality conditions.

The biological sampling routine used here was designed to obtain an
overview of the benthic invertebrate communities in the Hogtown Creek
and was by no means an exhaustive characterization of the entire benthic
system. Variations in both time and space can be expected in the benthic
communities of any flowing body of water. Benthic data presented in
this report should be viewed as a preliminary guideline in assessing the
relative condition of various portions of the creek.

The number of benthic invertebrate species collected from Hogtown
Creek ranged from a low of two at station 20 to a high of 21 at station
9 (Table VII-6). The number of individuals collected ranged from a low
of 569/m at station 11 to a high of 77205/m at station 14. Both
stations D-4 and D-1 were dry at the time of sampling and will not be
considered in the following discussion. A composite species list of
benthic invertebrates collected from the 14 non-dry stations along the
Hogtown Creek is presented in Table VII-7.

Stations 2 and 5 were similar in both number of species and diversity
as measured by the Shannon-Weaver diversity index (H') (Table VII-7).
Both stations were dominated by midge larvae and also contained lesser
numbers of Oligochaetes, Pelecypods and Ephemeroptera. Overall, stations
2 and 5 appeared to be two of the most diverse stations sampled. Station
4 contained fewer species than stations 2 or 5 and was also dominated by
midge larvae with Polypedilum sp. being the single most common species.










Table VII-6


Number of benthic invertebrate species and
site diversity, H'.


Shannon-Weaver


Station No. Species


No. Individuals (/m2 )


10500
20999
9458


SH' **Biomass (R/m2)


2.6
2.5
2.3


13.88
0.73
0.38


D5*


1453
2089
14088
4545
567
2452
11045
17772
4294
61864
16410


2.7
2.0
2.5
2.2
2.2
1.7
1.5
0.8
2.3
0.2
0.1


2.24
7.96
0.32
0.30
0.05
19.28
1.98
0.74
0.34
8.67
3.55


* Station dry at
** Values are for


time of sampling.
ash-free dry weight


after combustion at 5500C.








Table VII-7 Composite benthic invertebrate species list.
organisms per square meter.


Each number represents the number of benthic


Station Number
Turbellaria
Dugesia sp.
Nemertia
Unidentified
Nematoda
Unidentified
Oligochaeta
Limnodrilus hoffmeisteri
Lumbriculus sp.
Branchiura sowerbvi
Gastropoda
Lanx sp.
Gyraulus altissimus
Physa sp.
Sphaerium sp.
Pelecypoda
Corbicula fluminea
Amphipoda
Hyalella azteca
Isopoda
Asellus sp.
Coleoptera
Ancyronyx variegata
Cyllopus sp.
Haliplus sp.
Stenelmis sp.
Tricoptera
Cyrnellus sp.
Cheumatopsyche sp.
Ephemeroptera
Baetis sp.
Ephemerella sp.
Stenonema sp.
Ameletus sp.


1 2 4 5


6 9 10 11 12 14


16 17 iq 9n


91 1091


341 45 91

45 23

91 1750 1341 796
23


68 45

91 205


23 45


91 205 91 45 23 76273


114 114

45 114

273 7069 16182


228


137


45 137


205 23


227 205 23 591


114


137 45

114
523


23

68 23

159
45








Table VII-7 continued...


Station Number
Odonata
Enallagma sp.
Progomhhus sp.
Didymops sp.
Gomphus sp.
Ag ion sp.
Nehallenia sp.
Collembola
Isotamurus palustris
Diptera
Bezzia sp.
Brachydeutera sp.
Stratiomyidae
Nemotelus sp.
Hemerodomia rogatoris
Tipula sp.
Chironomus carus
Tanytarsus sp.
Cricotopus sp.
Cryptochironomus fulvus
Ablabesmyia paraj anta
Paralauterborniella sp.
Polypedilum sp.
Polypedilum halterale
Trichocladius sp.
Rheotanytarsus sp.
Chironomus attenuatus
Thienemanniella sp.
Paracladopelma sp.
Dicotendipes modestus
Coelotanypus sp.
Stenochironomus sp.
Xenochironomus sp.
Tanypus carinatus
Procladius sp.
Tribelos
Chironomid Pupa
Unidentified larvae


1 2 4 5


6 9 10 11 12 14 16


17 1 ?0


45
68 23


23
205


364
11750
319


205

7387
45 4


318 45
137

569
432

23


477 13978
318
23
477 205
387 23
568 2682
864 45
91 45
91


7591 2546
1364
23 227
1546 409
23


9523
23
23


23 68
23
273


45


136 23


146
341


1864
23


2387 159 114 273 91
137
23 45 23 68
614 23 23 23


45 23


1114


387
4341 273
91


1955


68
23
1955 886 159 45 23


6887 1409

23


68 23










Station 1 was located next to Haile Sink at the southern most
extent of the Creek. The benthic community at this station was fairly
diverse with 16 species and a Shannon-Weaver diversity of 2.7. The
total number of individuals at this station was fairly low with 1477
organisms per meter square. Representatives of the Turbelloria, Nemertia,
Nematoda, Oligochaeta, Molluska, Amphipoda, Ticoptera, Ephemeroptera,
Odonata and Diptera were all present at station 1. No single species
was found to be very dominating at this station.
2
Station 17 contained 11 species and 2094 organisms/m This station
appeared to be less diverse in species richness and was dominated by the
Oligochaetes Limnodrilas hoffmeisteri, Branchiura Sowerbyi and the
pelecypod Corbicula fluminea.

Stations 9 and 10 were similar, with 21 and 17 species respectively.
Station 9 had a considerably greater number 2f individuals (14184 organisms
per m as compared with 4647 organisms per m ) while both stations had
similar values for HI'. Both stations 9 and 10 were dominated by the
midge larvae Polypedilum sp.

Stations 11 and 12 had similar numbers of species, 10 and 13 species
respectively, but station 11 had less than one fourth of the total
number of individuals. Station 11 had the smallest number of individuals
of any station in the present study, and it was dominated by both the
ephemeropteran Baetis sp. and the midge Polypedilum sp.
2
Station 6 contained 16 species and 11049 individuals/m2. The
Shannon-Weaver diversity was fairly low (1.5) due to the heavy dominance
by the dipteran Tanytarsus sp. and Ablabesmyia parajanta.

Station 19 contained 10 species and was heavily dominated2by Polypedilum
sp. which contributed 9523 out of a total of 17815 organisms/m Due to
the heavy dominance of a few species, H' for station 19 was low (0.8).
2
Station 16 contained 15 species and 4377 organisms/m2 This station
was dominated by Diptera larvae and had an H' value of 2.3. Stations 14
and 21 were the least diverse areas studied with 7 and 2 species respec-
tively. Both stations had very low values for H' (0.2 and 0.1 respectively)
and were heavily dominated by the oligochaete Limnodrilus hoffmeisteri.

Information on the environmental condition of a stream can be
obtained by looking at the distribution of various indicator species. A
number of species such as Limnodrilus hoffmeisteri and Chironomus attenuatus
are known to tolerate low oxygen conditions and are often found in large
numbers in polluted areas. In a study by Mason et al. (1972) an attempt
was made to group benthic invertebrates into pollution tolerant and
intolerant categories. This grouping was based on the ability of the
species to tolerate low oxygen conditions brought about by organic
pollution. In the case of the Hogtown Creek, conditions other than low
oxygen concentrations also are of concern relative to the distribution
of benthic species. Therefore, simply considering the presence of
indicator species based on oxygen stress, may be misleading.










Although a more extensive sampling program is needed to completely
characterize the benthic invertebrates of Hogtown Creek, a gradient of
decreasing diversity (both species richness and equitability) can be
detected from the present data. Stations 2, 5, 1, 9, 10 and 16 appear
to be more diverse and thus in a better state of "health" than stations
19, 14 and 21.










VIII. SUMMARY AND CONCLUSIONS


SIGNIFICANCE OF URBAN DEVELOPMENT

The City of Gainesville has experienced a rapid and sizeable growth
over the past few decades and has developed into a major metropolitan
area in north-central Florida. As in any expanding urban area, growth
of this type brings about changes in land use and a clearly visible
alteration in the hydrology of the region. In the case of Gainesville
these changes have a special significance since there are no surface
outflows from the area. The sink hole systems of the region have a
limited capacity for accepting runoff, beyond which backwater and flooding
result. This fact has been illustrated with increasing frequency in
recent years as runoff rates and volumes have increased with residential
and commercial development. Concomitant with hydraulic constraints are
the natural limitations of the stream systems to accept waste discharges
and polluted runoff.

The last major flooding in the basin occurred in October 1970 when
a tropical storm passed over the City. This sparked local interest to
the extent that a city flood control ordinance was passed in 1973 prohib-
iting development in the 10-year flood channel and restricting it in the
100-year flood plain. Requirements for detention to contain the 4-year
storm volume followed. That serious flooding has not reoccurred since
1968 may speak partially to these ordinances but is more likely attribut-
able to the absence of large storms since that time. However, with the
large number of detention/retention basins now constructed in the City,
the flooding potential has probably not been greatly worsened since the
early 1970's. But heavy rains could again cause innundation in low
areas, particularly in the area southwest of West University Ave. and SW
34 St.

Gainesville enjoys a rather mild climate with temperatures averaging
70'F over the year and rainfall near 54 inches. Much of the rainfall
comes during late summer and has a considerable effect on flows in the
Hogtown Creek system. Most of the Hogtown Basin is residential in land
use, with commercial areas along University Avenue and on NW 13 St.
Continued growth in both sectors is expected over the next few decades,
expanding to the boundary of the basin, approximately 23 square miles in
area. The geology of the area is karst in nature with scattered sink
holes. Local groundwater serves as the base level for the flatlands and
prairies. Soils in the area range from very poorly drained to well
drained, with the ecology being predominately hardwood flood plains,
wetlands and marshes.

The City and public are aware of many aspects of the changing
hydrologic and quality characteristics of Hogtown Creek. Newspaper
articles and ordinances followed the flooding of the early 70's. Recently
the quality of water in the creek has been in the limelight due to City
Commission action on a construction setback line and several newspaper
articles about the condition of the creek (e.g., most recently in the
March 24, 1981 edition of the Gainesville Sun). Based upon observations
made during this study and by many others, storm water runoff obviously
contributes most of the visible pollutants to the creek. (The chemical










and biological parameters are discussed below.) This will increase with
increased urbanization. And other problems, such as the phenolic leachate,
are wet-weather related.

Current flood management efforts include stormwater detention/reten-
tion basins, installed for quantity control. These also act as sedimen-
tation basins and provide a measure of quality control. This effect has
not been demonstrated in this study due to a lack of sufficient rainfall
during the sampling period. (However, extensive sampling is being
conducted elsewhere under several current EPA National Urban Runoff
Program projects.) Efforts are underway to maintain open space and
flood plain buffer areas for both quantity and quality control. The
retarding effect of the flood plain vegetation reduces the downstream
impact of floods. The vegetation itself filters out floatables and
sediment. Its effect on chemical and biological parameters depends upon
the detention time of the water in the flood plain and is difficult to
quantify. For detention times of only a few days, probably few soluble
nutrients, for example, would be removed. However, most particulate
matter would be. Acquisition of flood plain lands by the City would
ensure their managed use for recreation and water quantity and quality
control.

It should be borne in mind that although a flood plain buffer is
good, it will not act upon the source of contaminants to the creek.
Other non-point source controls such as street cleaning, detention/reten-
tion basins, erosion control, etc. will be necessary to reduce existing
sources of pollution from highways, commercial areas and developments.
Improved public awareness has the potential to reduce contamination from
home fertilizer, pesticide and herbicide applications. However, this
study did not document a cause and effect relationship between stream
water quality and household activities.

DATA BASE

The hydrology of the Hogtown Basin has been studied by a number of
concerns but usually with flood control and property protection as the
impetus. Studies of the effects of pollution on the stream system have
been confined mainly to the upper reaches of Hogtown Creek and were
directed specifically at the Cabot Carbon phenolic wastes. Probably the
most comprehensive overview of water quality and aquatic biota was
presented as part of the 201 Plan, but dealt mainly with the region
surrounding Haile Sink. A more complete study of the stream system as a
whole has been lacking.

This study monitored several water quality parameters, as discussed
below. However, it did not explicitly deal with all parameters listed
under Chapter 17-3, "Pollution of Waters" in Rules of the Department of
Environmental Regulation. Moreover, instrumentation was not available
at the time of the sampling program to identify phenols, pesticides and
herbicides. (The Dept. of Environmental Engineering Sciences at the
University of Florida now contains a GC-Mass Spectrometer for this
purpose.) Hence, further studies would be needed for a more thorough
assessment.









Finally, flow monitoring was difficult at most stream locations
because of its shallow nature. Even at the weir at NW 34 St. measurement
was inaccurate because of the very shallow depths (a few inches) of
flows over the weir crest. In future studies, greater accuracy could be
achieved only with extra funding for installation of temporary flow
constrictions such as Parshall flumes or V-notch weirs. This is also
true at detention ponds where only a sizeable storm raises inflow and
outflow levels to depths at which they can be monitored.

WATER C'- ITY MONITORING

Several water quality parameters were measured in four manners:

1. Three stations (Possum Creek and the Main Branch at NW 16
Ave., Hogtown Creek at NW 34 St.) and two detention ponds were
monitored weekly for 15 weeks, from February 4 to May 14,
1980.

2. Fifteen stations were monitored twice during the study, once
during a relatively wet period, April 3, 1980, and once
following a relatively dry period, May 14, 1980. These were
the synoptic surveys.

3. A storm event on January 6, 1980 was sampled intermittently
for 28 hours at NW 34 St.

4. One sediment and benthic survey was performed.

Sampling sites are shown in Figure IV-! and the results discussed in
detail in Chapter VII.

From the weekly monitoring, the total flow at NW 34 St. was greater
than the sum of the two tributaries along NW 16 Ave. Generally dry
weather prevailed during this time period, and the flood plain area
upstream from NW 34 St. apparently contributed additional base flow.
Additional flows could also have originated from unmonitored tributaries
such as Rattlesnake Branch. During storm events the upstream flood
plain attenuates flows.

From the weekly monitoring, some parameters were found at fairly
low levels and typical of natural waters, but others were not. For
instance, turbidity and color were higher than nearby natural streams.
Although BOD was lower than "typical" stormwater, it was nonetheless at
levels characteristic of other urban rivers where stormwater may be a
problem. Nitrogen levels were comparable to urban stormwater and higher
in some forms than found in most natural streams. TKN exhibited a
"first flush" phenomenon during storms, indicating that it built up
during dry weather.

Phosphorus levels were quite high, and comparable to Florida rivers
draining phosphate laden soil. Oddly, however, it does not seem to have
increased dramatically in 28 years. The creek is probably nitrogen
limited due to these high phosphorus levels.




Full Text

PAGE 1

Publication No. 59 AN ENVIRONMENTAL STUDY OF HOGTOWN CREEK IN GAINESVILLE; FLORIDA ,,:. '-; by ..' ,' .. :.. : .' .. ',:. -,,::' : '''. ':"; ... :,,:.: Wayne; Patrick L. Brezonik ,': .. ::; .'.:. .: :"' '. and ... ." : ; ..... .. P. Heaney -.:' "..

PAGE 2

March 1981 AN ENVIRONMENTAL STUDY OF HOGTOWN CREEK IN GAINESVILLE, FLORIDA by WayneC Huber, Patrick L. Brezonik and James P. Heaney Faculty Investigators and Michael G Cullum, Donald J. Polmf-nn and Gary F. Goforth Student Investigators Dept of Environmental Engineering Sciences University of Florida Gainesville, Florida 32611 Sponsored by Florida Dept. of Environmental Regulation Tallahassee, Florida and Engineering and Industrial Experiment Station University of Florida Gainesville, Florida

PAGE 3

ABSTRACT Hogtown Creek Drainage Basin is situated within the growing urban area of Gainesville, Florida. Draining the predominately residential and commercial areas of western Gainesville, Hogtown Creek and its tributaries are being affected by the changing volume and quality of runoff associated with urbanization. These changes are manifested in: 1. increased citizen concern; 2. increased presence of visible and floatable material; 3. increased flows due to greater runoff resulting from increased ,imperviousness of the area; 4. increased aesthetic degradation; 5. increased turbidity; 6 high fecal and total coliform counts. The creek system is also'bearing the impact of an industrial waste and a municipal wastewater effluent. This to analyze the impact of urbanization on the receiving Efforts included: a review of previous investigationsandaffi1iated1iterature, field surveys, weather monitoring, stream gaging,water quality sampling, sediment sampling, and an examina tionofbenthic communities'. The resultsoftheselnv.estigations provide a baseline understanding of HogtownGreekw'ith regard to climate, geology, soil types, land use,hydro1ogy, ecological communities, point and nonpoint pollution sources, stream flow arid water quality. ii

PAGE 4

TABLE OF CONTENTS Abstract Table of Contents List of Figures List of Tables Acknowledgements I Introduction and Objectives II III IV v VI VII Hogtown Creek Project Objectives Tha Gainesville Area Drainage Basins Rainfall 0.. Land Use/Population Geology Soils Previous Inves tig.::itions Hydrology Ecology -20,lP 1-an .. IndustrialWaste Dredge and-FilL.pernuts i'-. ... . Db j ec ti yes. .' .. -'c Point Nonpoint Source Locations Po int.'-;,'Source'g' Nonpoint Sotlrces Current Flood Nanagement Structures -Detention Basins Basin Descriptions Application of SWMM VlsualImpacts ofStormwater Runoff Sampling Network EcologicalSurvey.. Riparian Communities .. Aerial. Photographs Quantity-Honi toring.oStream Flow. Gaging 0 Weather Monitoring Stream Quality Monitoring Introduction .,. Methods Sampling Sites Sampling and Analytical Methods ... Chemical and Physical Characteristics of Stream Sediments . Benthic Invertebrates Results and Discussion Weekly Sampling of Hogtown Creek Weekly Sampling of Detention Basins Summary of Weekly Sampling Surface Water Synoptic Sampling Sunrnary of Synoptic Studies Water Quality in Hogtown Creek during Sediment Studies ... iii a Storm Event ii iii v vii viii 1 1 2 3' 3 3 7 7 12 16 16 16 16 17 17 18 18 18 18 18 23 23 23 23 27 28 28 31 33 33 33 37 37 37 37 38 40 40 42 42 60 63 64 76 76 77

PAGE 5

TABLE OF CONTENTS VIII Summary and Conclusions Significance of Urban Development Data Base Water Quality Monitoring Detention Ponds References Appendix A: Photographs of Detention Basins and Creek Sample AppendixB: Appendix C: Appendix D: Appendix E: Sites Physical Characteristics of Selected Detention Basins Rainfall Recorded at Gainesville, Florida Description of Vegetative Communities Water Sampling Data iv 89 89 90 91 93 94 97 103 112 115 120

PAGE 6

Figure 11-1 11-2 11-3 11-4 11-6 IV-l IV-2 IV-3 V-I V-2 VI-l VI-2 VI-3 VII-l VII-2 VII-3 VII-4 VII-5 VII-6 VII-7 VII-8 LIST OF FIGURES Location of Gainesville, Florida. Drainage Basins in the Gainesville Urban Area Flood Prone Areas of Hogtown Creek-Existing Development Proposed Land Use, Gainesville, Florida Population Districts, Gainesville, Florida. Soil Types in the Study Area .' Location of Sampling Si tes and Rain Gages "-.. -.. IiJ.eritifiea'po:f.nt and Nonpoint Pollution Sources. : ---". Locat{onofStormwater Detention Ponds ,Schematic of Riparian Communities Vegetation: and. Land Use of Hogtown Creek Drainage Basin Minimum Daily, Maximum Daily, Average Monthly Flows for Hogtown Creek 'Monthly Averages of Rainfall, Evaporation and Creek D.ischarge Daily Rainfall Totals, Gainesville, Florida, February-July, 1980 pH vs. Weekly Sample Period pH vs. Color, Three Weekly Sites Dissolved Oxygen vs. Weekly Sample Period Nitrate + Nitrite vs. Weekly Sample Period TKN vs. Weekly Sample Period TKN Load vs. Weekly Sample Period Nitrate + Nitrite Load vs. Weekly Sample Period Ammonia Load vs. Weekly Sampling Period v 4 5 6 9 10 14 19 21 24 29 30 34 35 36 44 46 47 50 51 52 53 54

PAGE 7

Figure VII-9 VII-IO VII-II VII-12 VII-13 VII-14 VII-IS VII-16 VII-17 VII-IS VII-19 VII-20 VII-ZI VII-Z2 VII-Z3 VII-Z4 VII-25 VII-26 VII-27 SRP vs. Weekly Sampling Period Total Phosphorus vs. Weekly Sample Period SRP vs. Weekly Sample Period .. Total Phosphorus Load vs. Weekly Sample Period. Suspended Solids vs. Distance Upstream -High Flow Sampling 4/3/S0 . Suspended Solids vs. Distance Upstream -Low Flow Sampling 5/14/80 Turbidit:y vs. Distance Upstream -High Flow Sampling 4/3/80 . Turbidity Distance Upstream -Low Flow Sampling 5/14/80 Color VS. Dis tance Ups tream -High Flow SamplingA!3! SO Colorvs. Distance Upstream -Low Flow Sampling 5/14/80 BOD_ vs. Distance Upstream -Low Flow ::; Sampling 5/14/80 Toe vs"Distance Upstream High Flow Sampling 4/3/80. TOC VS. Distance Upstream -Low Flow Sampling 5/14/80 Cluster Analysis of Fifteen Sites Storm Hydrograph and Conductivity Levels, Single Rain Event, January 22-Z3, 1980 ...... TKN and Turbidity vs. Time, Single Storm Event Soluble Nutrient Concentrations vs. Time, Single Storm Event Concentrations of Major Ions vs. Time, Single Storm Event. .... Concentrations of Carbon Forms vs. Time, Single Storm Event. . vi 56 57 58 59 65 66 67 69 70 71 72 74 75 76 78 79 79 80 80

PAGE 8

Table 11-1 11-2 11-3 II-4 IV-1 IV-2 IV-3 V-1 V-2 VII-1 VII-2 VII":"3 VII-4. VII-5 VII-6 VII-7 LIST OF TABLES Long Term Average Precipitation Long Term Average Temperature Population by District, Gainesville, Florida Soil Type Characteristics Location of Sampling Sites and Rain Gages Identified ,Point and Nonpoint Pollution Sources Number .ofStorm Sewer Pipes Location 6f StorInwater-Detention Ponds Representatfve;Vegetation in Riparian .... Communi.ties .. e... .. -Use of Hogtown Creek Drainage Basin 0:> Index to Figure VI-2 -. Chemical ancC:Siologica1 Parameters Biological_and Chemical Data. Summary for Three -,-:WeeklY,Iiistream Sites Duncan11ultip1e Range Test for Selected .. Parameters, Weekly Sample Period Characteristics of Stormwater from Florida Sites .. Sediment Analysis Results Number of Benthic Invertebrate Species and Shannon-Weaver Site Diversity, H' Composite Benthic Invertebrate List. Each Number Represents the Number of Benthic Organims per Square Meter vii 8 8 11 15 20 22 25 28 32 39 43 61 81 82 84 85

PAGE 9

I ACKNOWLEDGEMENTS Gratitude is expressed to the many people and agencies which aided the study: Ron Ferland of the Alachua County Pollution Control District; Dave Zeno and Emery Swearingen of the City of Gainesville Department of Transportation; John Cox, Richard Drew, and John Ruddell of the Florida Department of Environmental Regulation; the North Central Florida Regional Planning Council; and the FAA Flight Service Station at the Gainesville Airport. At the University of Florid?, the Agronomy Department supplied data and RonBes't,Pete Wallace and Bill DeBusk, from the Center for Wetlands made ecological evaluations. Within the department of Environmental Engineering Sciences special thanks are extended to Elaine Wallace for field sampling 'arid chemical analyses and to Randy Schultz for benthic invertehratedeterminations. Among those also responsible for chemical analyses'-or other assistance Cwere Charlie Fellows, Carl Miles, Debra Butner,-JacJiTusehall, Larry Baker, Donna Iozia, Curt Pollman, Chuck-Hendry,
PAGE 10

I. INTRODUCTION AND OBJECTIVES HOGTOWN CREEK About two thirds of the City of Gainesville, Florida is drained by Hogtown Creek, a stream of about ten miles in length along the main branch, originating in pine flatwoods in the north central part of Gainesville, and draining to Haile Sink, to the southwest of the City. Although the tributary land use is predominantly residential, there are also severalcolIl.mercial and light industrial sites within the approximately 23 square mile. basin. And, of course, 'the creek is the recipient of many m:U.esof highway drainage. Baselowisprovidedby continual entry of groundwater from the surficial aqUfer.But, .as in most urban areas, the flow during wet weather.cons:Lstsmainly of non point source runoff from the urban land uses combinedmth subdivision drainage ditches and storm sewer outfalls, although::thereare still":large, undeveloped portions of the flood plain extant along. i:hecreek Asurbanization intensified, especially in some of the.headwa.ters areas of .the creek .(e.g., Possum Creek), noticeable changes have occurred. in cqior, sediment. load and visible "pollutants" (e.g.,floatablesandfoam);;At the headwaters of the main branch, special:cQclJ)r, aesthetic and.: possible public health problems have arisen because of seep'age of.phenolic.wastes into the creek. In addition, one smallsewagetreatmer"tplan.:t:in the Northwood subdivision of Gainesville dischargesinto .. theheadwat:-ers of possum=Creek. __ ;. c_ Host of its length, Hogtown Creek is,aesthaticallyand-visually pleasing,withmature mixed hardwood forests and flood plain swamps. It is popular as a recreation area for hiking,nat:ure walks, etc..' .i\:lthough not generally perceived as a stream used for water children frequently play in it. There have also been instances of tubing in the creek during high water. It is both anomalous and discouraging. that one of the most attractive reaches, behind the GainesvHle. Mall Shopping Center has been the recipient of well over 100 junked shopping carts. Aesthetic impacts are thus.very important; however, increasing concern is also being expressed regarding chemical and biological water quality characteristics. This is especially relevant do\vustream, since Haile Sink interacts with the Floridan Aquifer, a potable water supply. An interesting feature of the basin is the presence of many stormwater detention ponds, in place Que to a city (and similar county) ordinance that requires storage of the additional runoff (over and beyond what occurred under natural conditions) due to development, for a four year return period storm volume. (According to the City, most developers actually provide for a ten year storm.) These detention and retention ponds have been instituted for flood control, but it is assumed that they also improve water quality because of the detention provided in the ponds. They also induce groundwater recharge. However,. little is known of a quantitative nature as to the ability of such ponds to improve water quality. I

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All of these consideratiDns have led to considerable interest in Hogtown Creek at a local and state level with regard to the effects of urbanization and point and nonpoint source runoff on the creek, and the effect of detention and retention ponds on runoff quality. Are water quality standards violated? Are beneficial uses such as water supply and recreation impaired? Is the creek likely to suffer further degradation? What is its character at the moment? How well do the detention ponds flli"J.ction? These are some of the questions that have led to this present study. Tha Florida Department of Environmental Regulation (DER) must prepare-:plansfor control and prevention of nonpoint source water pollution problems associated with urban activities. Hogtown Creek is an ideal test watershed for-this purpose, in which can be studied impacts and controls., -, Specific project objectives follow. the of urban development in terms of impairedhenefiCialuse-o.tlie waters of Hogtown Creek. This is to be accomp-lished=l.npart throUgh' a, literature review, a field survey of the ," --.;-,> .::-.---,",--2 .. > data base necessary for the abDve used in study is to be well documented and data needss12ecified.-' -' 3. Establis"h>a>wateJ:,"quality-monitoring program at several locations in the .basinto.-service of objectives 1 and 2. ,-" 4 :-DocUIP..ent.the quality' performance of selected detention' ponds A very useful byproduct:of the study is the preparation of maps, tables, etc. thatd'etail the hydrologic, ecologic and demographic charac.teristics of t:l:leliogtown Creek basin. 2

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II. THE GAINESVILLE AREA DRAINAGE BASINS Gainesville is located in the north-central region of Florida, as illustrated in Figure II-I, and encompasses the major portion of the metropolitan area of Alachua County. Most of the Gainesville Urban Area (GUA) lies in an area of approximately 300 square miles from which there is no surface outflow. All urban, agricultural and wetland runoff in this area is returned to the upper zone of the Floridan aquifer by a system of local streams flowing to naturally occurring sink holes. The principal systems of the urban area are the Sweetwater Branch/Alachua Sink systeru, which drains eastern Gainesville, and the Hogtown Creek/Haile Sink System draining western Gainesville. The proximity of these systems to other drainage basins in the area is illustrated in Figure 11-2, which presents an overv--iew of the GUA. Hogtown Creek has its headwaters in the north-central region of Gainesville and drains in a southwesterly direction.The major tributary to Hogtmm Creek is Possum Creek, contributing flmvfrom the northwest area of the city The boundary of Hogtown Creek Drainage Basin has been delineated in the North Central Florida Regional Planning Council-{NCFRPC) report, prepared by Sverdrup & Parcel, subtitled Drainage (1974) .. and is shown in Figure 11-2. The report also identifiedsub':"basins within the Hogtown System, flood-prone areas (see Figure 11-3) ,major structures" and the topography of the overall basin. A complete set of maps accompanies the NCFRPC report in scales of 1inch:lOO-feet and The basin boundaries are not constant inasmuch as developments along the perimeter contribute ne,v area through drainage--tl1at. enter -the' basin. Surface flow in the basin receives a contribution from two springs along the flood channel. In the USGS publication, Springs of Florida, there is a flow record for Glen Springs> located adjacent to Hogtown Creek near NW 2:lrdBlvd. The latest flo"rmeasurement was reported in j 1972 as 0.30 ft /sec. A second spring is located behind the Gainesville Mall parking lot; just north of 23rd Blvd. and below the outlet of the storm se-.;"er pipes. No quantity or quality data ,-,ere available for this spring. The area encompassed by the Hogtown Basin has been reported by several sources, but with quite a disparity. Christensen et al. (1974) reported a value of 22 square miles obtained from the Army Corps of Engineers, while their own calculations showed 27.38 square miles. The NCFRPC reported 20 square miles, while the USGS reported a value of 41.6 square miles. Based on maps furnished with the NCFRPC report, the total land area the basin boundary was calculated on a Hewlett-Packard model 9864A digitizer to be 22.5 square miles. Inside the boundary are 3 square miles of depression basins which do not contribute surface flows to Hogtown Creek. Therefore, the total drainage area for the creek was calculated to be 19.5 square miles. RAINFALL Rainfall in the Gainesville area is abundant and temperatures are mild. Long terTII monthly averages for rainfall and temperature are 3

PAGE 13

I l I '(..7' \.. .,,' sV .... f W'7 '7/ ". Tt r'---.... HQGTOWN .... .. .. ,J., ,:>.. r CRE;.:K. I I L, (-(')"\ i .J c;" i ViLLE\ ) ;;-.}" I i LV,.. 0-..1./ I ..-r-'< I I It Figure II-I. Location of Gainesville, Florida and Creek. 4

PAGE 14

V1 A p '/ -' ; I, ______ J. ____ ",,', '\. / I ,-' \,,' ) ( HOGTOWN \/,' l --.1 ) I ''} \. \ 1 J ,I ", \ / .) I '/ '"'-\ i / /' ,J \., i ( I, '< i I ,) en ( / '''---'1----1,.-. 7-', ......... -, PAYNE'S PRAIRIE o I MILE I I t I Figure II-2. Drainage Basins in the Gainesville Urban Area. From North Central Florida Regional Planning Council, 1974. AIRPORT NEWNAN'S LAKE

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0\ MILE CLEAR LAKE 2 DOWNSTREAM SR 26A TO 34TH ST. :3 8TH AVENUE 4 SPRINGSTEAD AND PINE FOREST CREEK 5 POSSUM CREEK AT 16TH AVENUE 6 THREE LAKES CREEK AT 34 TH ST. Figure II-3. Flood Prone Areas,. of Hogtwon Creeek Drainage Basin -Existing Development

PAGE 16

presented in Tables 11-1 and 11-2, respectively. The yearly average temperature is about 70F. Rainfall averages about 54 inches per year and has ranged from as little as 35 inches to as much as 80 inches. In a typical year about 60 percent of the' annual rainfall occurs from June through September as local afternoon or evening thunderstorms and showers. Rainfall during other periods is usually the result of large scale frontal systems. Periods of deficient rainfall occur in many years, particularly between November and May. Precipitation, temperature and pan-evaporation in Gainesville are recorded daily at a University of Florida Agronomy Department station. Data are available through the Nation2.l Climatic Center, Asheville, N.c/., as part of NOAA Climatological Data. Various other sources of unpublished data exist in the area such as the FAA Flight Service Station at the Gainesville Airport and intermit,.... tent university studies. Two weighing bucket rain gages were utilized as part of this study. LAJ."ID USE/POPULATION Proposed land use within RogtownBasin is illustrated in Figure 114, which sUlluriarizes the Comprehensive Land Use Plan developed by the Department of ConLTtlUnity Development, City of Gainesville. The plan is intended to cover the period 1980-2000. Rogtown Basin is predominantly a residentia.l area, as is much of Gainesville. Population projections for Gainesville have been prepared for 18 planning districts by the Department of Community Development. The districts are shown in Figure 11-5 with corresponding populations given in Table II-3. The Metropolitan Transportation Planning Organization (a department of NCFRPC) report entitled Socioeconomic Growth Analysis (1979) established 235 traffic analysis zones in the GUA. For each zone, the number of high density dwelling units) the total nu..'llber of dwelling units and the total population is reported for 1977, and projected for the years 1990 and 2005. It maybe observed that several of the population zones in the Rogtown Basin are projected to increase by 2000 or more persons in the next 20 yearse As already mentioned, the increased imperviousness and intensified land use associated with such an increase in population can be expected to aggravate water quantity and quality problems within the creek system. Whether the proposed natural buffer adjacent to the creek will actually be provided depends at present upon the generosity of land o,mers who may donate the land to the City. If a $2.5 million bond issue on the November 1981 ballot is approved,. the City .could purchase much of the land. This would be highly desirable since the flow retarding and cleansing action of the flood plain could thus be preserved. A moritorium on construction '><7ithin 25 ft of the creek center line is in existance since November 1980. It may be expanded in the future pending various feasibility and engineering reports. GEOLOGY The geology and geomorphology of Rogtown Basin are examined in a thesis by S.R. Marcus (1971) and can be summarized as follows. Alachua 7

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Table 11-1. Long Term Average Precipitation, Gainesville, Florida. Honth Rainfall, Inches/Honth January February Harch April Hay June July August September October November December Yearly average 2.84 3.70 4.26 3.02 3.54 6.81 8.03 8.25 5.67 3.67 1.92 2.88 54.59 inches :Period of Record 1941-1970. From Climatological, Data Gainesville Station-3 WSW University of Florida Agronomy Department Table II.:c.2. Long Term Average Temperature, Gainesville, Florida Houth Temperature, January 57.0 February 58.6 Harch 63.6 A ., __ prll. 70.0 Nay 75.8 June 80.0 July 81.1 August 81.2 September 79.1 October 71. 8 November 63.3 December 57.8 Yearly average 69.9 Period of Record 1941-1970. From NOAA, Climatological Data Gainesville Station-3 WSW of University of Florida Agronomy Department 8

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I.D Figure II-4 4 4-SW 20 AVE Proposed Land Use, 1980-2000, Gainesville, Florida From Department of Community Development, 1979. \-0' 1 ::>'J 7 5 !!!.! 23 t.YE '( t MILE PLANNED RESIDENTIAL DEVELOPMENT 2 MULTIPLE FAMILY 3 RECREATION I BUFFER 4 INSTITUTIONAL 5 COMMERCIAL/ INDUSTRIAL/ OFFICE/ UTILITY 6 AGRICULTURAL 7 SINGLE FAMILY

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b 1 '" I 2 MILE .,.",.,.,. 14 Figure 11-5 __ Population DistricJs,_ Ga,inesville, Florida_._

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I-' I-' Table 11-3. Population by District, Gainesville, Florida POPULATION PROJECTIONS BY PLANNING DISTRICT -2000' 1979* 1980 ','r ". 1995 I 2000 .',' J I I l' 753 900' --1,500, 1,800 2,050 ", 4 948 (795 4 950 ,5,450 6,2'25' 7 000 8 000 3 2,390 2,650 2, \350 3,100 3,350 3,700 I---, ',5 150' 4 3,699 (206) tJ, 550 ,! 5,750 6,250 ---,-------' -;. '---'-5 3,252 3,500 4,000 4.075 4,150 4,200 I------'-.,..... --'-' ---' -. ..:.....; -:-' 6 6,916 7,550 $ 250 ,'I ; ..-.:-9,450 9,900 en f--, -.-' ,----' +> 7 2,604 3,150 ,950' ;" 4,,600 5,250 5,800 C) .r{ H 3 922 4 400 5 400 6 550 7 700 9 250 ..., en 9 8,285 (19) 8,200 8,650 9,250 9,850 10,500 .r{ C\ 10 8,019'( 1480) 8,500 9,250 9,950 10,p50 11,550 bJl 11 5,647 (24) 5,700 6,000 6;650 7,300 8,050 .r{ e--; -12 3,788 3,950 4,750 .. 5,900 7,050 8,500 C
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County is divided into two major topographic regions, a western karst plain about 90 feet above sea level and an eastern plateau, the Okeefenokee Terrace, ranging from about 175 feet down to 150 feet above sea level. Rogtown Creek is now cutting headwards into the plateau, working to reduce it to the level of the karst plain. The karst plain has been lowered by solution to the present level of lakes and prairies, at or near the local water-table base level. The major structural feature of the area is the Ocala Arch, the crest of which is now occupied by the karst plain. East of the axis of the arch the Okeefenokee Terrace has been uplifted to around 175 feet, whereas it is found elsewhere to be around 120 to 140 feet. The slope of the plateau is eastward. A distinctcirainage divide exists in the Gainesville area between Rogtown Creek and Little Ratchet Creek In other areas of the terrace, a distinct pattern of drainage is lacking. Thus, most of the Okeefenokee Terrace is a pine-palmetto flatland with extremely poor surface drainage. Rogtown Creek lies within the Central Highlands physiographic province of Florida. Gently rolling hills are scattered with sink holes, and lakes are found at the margins of a flat terrace. Underground drainage is predominant in these areas, being highly developed west of Gainesville; Surface runoff dominates in the terraced areas, with much of the runoff eventually disappearing into sink holes. n,...,a.-t-o-'-"'-a-"",",-,-,r1 t"'rrace exrand from near the .. __ do J c headwaters of HogtmvnCreek do,mstream two-and-one-half miles, or about one-halftne-lengthof these tributaries. Incised meanders occur along the ter:i:"aced stretches of Rogtown Creek, indicating that the creek has been subjected to periods of stability and rejuvenation. The rejuvenation consisted of one majorpost-Aftonian stage and one or more subsequent events. HogtownCreek flows into a prairie from which there is no surface drainage. Its base level is the local groundwater level. The drainage basin exhibits a dendritic_pattern thoughout due to the uniformity and horizontal stratification of the underlying material. The level of the water on the prairie is about 60 feet above sea level. The creek terminates at Haile Sink, which drains to the Florida aquifer. The level of the potentiometric surface of the Floridan aquifer is approximately equal to that of water on the prairie. SOILS Figure 11-6 is a map of the soil types in Rogtown Creek Drainage Basin. The soils are classified with respect to drainage as defined by the soils descriptions provided in a USDA Soil Conservation Service Special.Soil Survey Report (latest revisions 1979). Along with soil types, urban areas (where greater than 70% of the surface is impervious) are designated on the map. Pits and dumps are also shown. Very poorly drained soils are found in the headwaters and in the southern reaches of Rogtown and Possum Creeks. Poorly drained soils, notably those in the Pelham series, make up much of Possum Creek and comprise the substrate in the area where Possum Creek enters Hogtmvn Creek. Moderately well drained soils are found off-stream, adjacent to 12

PAGE 22

the soils which make up the stream bed. The northern and central reaches of Rogtown Creek are composed largely of well drained soils, notably of the Kanapaha sand series. The quality and quantity of runoff from these soils are functions of the characteristics presented in Table 11-4. Erosion and subsequent sediment loading potential are functions of particle size and slope. 'In general, the smaller the particle size and the steeper the slope the greater the erosion potential. The amount of: runoff is a function of the imperviousness of the area. Soil permeability is reflected in the hydraulic conductivity and moisture capacity and ultimately, the drainage classification of 'each soil type. The majority of the area in the Rogtownbasin contains moderately well to welL drained soils, implyingtha t runoff (from natural land cover) is re1atively low. In the 1974 NCFRPC Drainage study, the basin_wide averagarunoffcoefficient (C in the rational Q = CiA) was estimated as 0.37.# 'Theeffect of increased urbanization on stormwater runoff can be quantified by determining the increase in the magnitude of C. The NCFRPC reno-rt'evaluated the. increase in the runoff coeffici'ent based on "-'" A projec.tedland use changes, and C was predicted to increase from 0.37 to O. 47 2000. 13

PAGE 23

I-' ..,... Figure II-6. C1J ,(]I] 1 2 Tfi.S! {".If\ '= "<: 3 7C j \2= k 1 '--UNIVERSITY AVE.;:; :3 MODERATELY WELL DRAINED I 4 WELL DRAINED 5 PITS AND DUMPS 6 URBAN AREAS 7 LAKES I MILE t I Soil Types in the Study Area. Note that the whole area is urbanized, and !'urban areas" on the figure means areas with greater thanperc.entimperviQusness. From USDA SoU Conservation Service, latest revisions. 1979.

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f-i V't I,. 'J )1 .. Table n':4.: ('1)1 .-... ----. ._L_. __ .. c ___ ._, '. ... "',.: Ii .... ,...,. Ava,ilable Hydraillic. CoriciuctivitY (inches/hi) i. Sog Erosion ". ; .. .. '\.'. '.. .. Watelt Capacity i... ..fot'enti20 2.6-8.5 4.2-14 2.5-8.2 >20 2.2-7.3 3.7-12 5.3-19 6.0-20 0.20 0.20 0.19 0.29 0.26. 0.21 0.27 0.17 0:28 0.20 0.19 0.17 (1) Soil properties averaged ov>r -80" profiles of 5 textures. (2) Values averaged over a 55" profile with the top 36" of muck. .. 100 100 1QO, .' .... ioo 98-100 87-94 84-92 100 96-100 100 100 95-100 95-100 100 95-100 100 95':100 97-100 90-100 95-100. 90-100 95-100 90-100 95-100 90-100 97-100 95-100 ," 88-100 78-95 85-98 69-90 85-100 67-90 90-100 75-100 90-98 75-95 84-95 85-lQO 82-95 77-95 75-95 85-100 (3) Defined as potential soil loss from "continuous fallow yrs) on 9% slope, 73' long." From USDA Soil Conservation Serv:ice, latest revisions, 1979. -26 5-20 9-23 26-37 21-42 9-24 7-17 16-34 1-12 21-34 9-26 21-31 2-8 22-38 13-24 5-40 13-20 <2 <2 <2 0-8 0-2 1-.-2 .. <2 0-8 0-2 0-8 0-8 0-8 1-8 1-8 0-5 0-12 0-15 0.09-0.14 0.14-0.18 0.09-0.14 0.08-0.13 0.08-0.11 0.07-0.12 0.06-0.09 0.09-0.15 0.02-0.05 0.10-0.14 0.07-0.12 0.10-0.13 0.02-0.05 0.11-0.15 0.06-0.11 0.06-0.10 0.07-0.10

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III. PREVIOUS INVESTIGATIONS HYDROLOGY The issues of flooding, flood control, hydrology of the creek and detention basins have been addressed in several reports. The most complete study is the NCFRPC report Drainage (1974), previously mentioned. In 1973 the NCFRPC presented Report on a Flood Plain and Water Control Progr&-n for the Headwaters of Little Hatchet, Turkey, Blues and Hogtown Creeks which studied the soil types, hydrology, and runoff characteristics of the upper reaches of the creek. A drainage study of a region at the head;;.;:aters of Possum Creek was conducted in 1973 by H. Green, a local consul:ting engineer. University of Florida studies include Krueger (1972): a hydrologic evaluation of a proposed natural retention basin; Vargus (1972): an evaluation of area parameters controlling storrnwater runoff;Christa.'1sen et ale (1974): an evaluation of natural detention sites; Victoria (1974): a computer model of the creek system including proposed. natural detention basins; and Doyle (1973): a study of land use alternatives addressing r.vater quality control associated with quan-The NCFRPCreport entitled Open Space and Recreation (1973) presented a comprehensive evaluation of recreation in Alachua County and offered proposals for major open space systems and parks for a 1980 program and 1990 plan. The Council advocated a multiple-use concept for the entire drainage basin and the development of several recreation areas along the creek. Environmentally Sensitive Areas (1975), a report by the Department of COT!lmunty Development, examined the geology, soils, slopes,landuse, vegetation, wetlands and sensitive areas of the Gainesville area. 201 PLAN The Alachua County 201 Wastewater Facility Plan For The City of Gainesville, Florida was completed in 1978 by CH2H-Hi1l, Inc. The report includes an environmental inventory covering such things as physiography, geology, soils, ground and surface water hydrology, climatology, plant and animal communities, environmentally sensitive areas, and archeological and historic concerns. Also provided are 1975 land use and population data, with projections to 1995. Existing water quality in the Gainesville area received comprehensive coverage in that report. Samples at Haile Sink in January, 1971 showed dry'-\veather pollution of Hogtown Creek to be "considerable", with biochemical oxygen demand (BOD) higher during storm runoff. Dry-and wet-weather water quality data for May and August, 1976, respectively, sho1;v moderate nutrient concentrations and high dissolved oxygen (DO).levels at Haile Sink. Aquatic biota at Haile Sink were also examined in 1976 .. A comprehensive background sampling program examining such things as metals, nonmetals, organics, and physical and biological parameters was conducted in 1977. Tests covered both groundwaters and surface waters in and around Gainesville. The 201 Plan also addressed the wastelvater treatment 16

PAGE 26

plant discharging effluent to the headwaters of Possum Creek. Discussions included effluent quality for 1974-1976 and plans to take the plant out of service in the near future. INDUSTRIAL WASTE Probably the most serious pollution problem in Hogtown Basin arises from phenolic wastes at the former site of Cabot Carbon, a company that produced pine tar products in the 1950's and 1960's. Lagoons in the vicinitYcoEHain Street and 23rd Blvd., near the headwaters of Hogtown Creek, received process wastes such as crude wood oils, acid water and pitch. As much as 6600 gallons of effluent per day is reported to have been discharged from theselagoons to a swampy area that fans out to a leading to liogtown Creek. An unknown number of lagoons were covered over after they were filled with settled wastes. As early as 1961, Sundaresanet al; (19:65) studies on the effect' of lagoon discharg?s onenec creek. The 'study concluded that effluent from the site caused_se'lferewater.qualitydegradationand had an adverse impact on creek creek recovery occurring 4.9 miles downstream from the discharge., The compalJ.y ceasea operations in 1966, but maj or discharges occurred in 1967 and 1977 during development and construction :A-Oiological survey of the upper 2.8 miles of Hogtow"Il. Florida Department of Environmental 1977,isliowed be devoid of life (except for bacteria) from thepoint;of dischargeto 6000 feet downstream. The U.S. Envirorunerttal Protecti:on Agency conducted a Hazardous Waste Investigation in December 1979. The study found phenol concentrations as high as1500'jlg!lcin surface:water, as well as 25 other organic compounds not area, 8 of which are listed asNRDC Priority Pollutants. Stream recovery in terms of a diversified macroinvertebrate community wasreported.to occur 5 miles downstream. The Alachua County Pollution Control Dlstrict., through its own investigations and the review of other studies,. has concluded that the problem existing today consists of continuous seepage of highly phenolic groundwater leachate into the North.Hain-Street drainage ditch, which empties into Hogtown Creek. DRED.GE AND FILL PER.1'1I;TS Current dredge and fill permits were reviewed as possible documentation of physical impact. The City of Gainesville has a five year permit for dredging associated with maintaining the Hogtown Creek channel and culvert under N.W. 8th Ave .. The permit calls for the soil to be trucked offsite, but current practice is to pile the spoils along the adjacent banks, where they are highly susceptible to scour and return to the creek. Gainesville D.O.T. has a permit for activ:i,ties related to the construction of a bridge spanning the creek at N. IV. 34th Street near University Ave. Silt screens were placed 50 feet downstream to control turbidity. There is no documentation on the effectiveness of these screens. The bridge construction began after the sampling period ended. 17

PAGE 27

IV. SITE INSPECTIONS OBJECTIVES On 23 April, 1980, a group consisting of representatives from the Florida Department of Environmental Regulation (DER), the city of Gainesville D.O.T., the University of Florida Department of Environmental Engineering Sciences, the Alachua County Pollution Control District (ACPCD), _and the University of Florida Center for Wetlands spent the day visitingtheifteen sampling sites and detention basins. The objectives included: 1. lo-cation of point source and nonpoint source discharges into -Jiogtown Creek 2. inspection of current flood management structures 3. discussion of visual impacts of urban stormwater runoff 4;cdiscussion of the sampling program oi:thehydrological, geological and ecological -charaCteristics of. each site The detel1tion ponds and __ rain gage locations are shown in Figure}Y::-l. andiTablerV LOCATIONS _PresentedincEigure"IV-2:are the locations of identified point and nonpoint:ciisCllarges into Hog town Creek. Table IV-2 enumerates the quantity and dimensions oECthe sources at each location. Figure IV-2 was compiled from storm sewermaps and conversations with personnel from anc.-AC:PCD."-:As indicated, approximately 110 storm sewer outfalls-comprise w'le majority of the number of point sources. A sewagetreatment--plant Northwood subdivision near the headwaters of Possum Creek contributes as much as O.5mgd of chlorinated effluent. The plant was designed for a capacity of 0.35 mgd and utilizes extended aeration treatment followed by polishing ponds. Approximately 50 open ditches provide surface drainage for the majority of the north and northwest areas of Gainesville. Figure IV-2 presents the location of ditches with a top width of 15 feet or greater. The majority of these terminate along the flood channel of Hogtown and Possum Creeks. There are also approxima.tely30 smaller ditches distributed about the city. The stormwater runoff from these ditches combines with the effluent from the large number of sto.rm sewer oui::falls and has a major influence on the quantity and quality of flow in Hogtown Creek following storm events. Nonpoint Sources The only documented nonpoint source is located in the northeast region of the basin near Main Street, where a drainage ditch empties into the creek after flowing near chemical dump sites once utilized by Cabot Carbon. As discussed previously this dump site has been documented to contribute phenolic leachate to the creek. 18

PAGE 28

o MILE / G3 AIRPORT SAMPLING SITES #F ON STREAM SITES o DETENTION PONDS G RAIN GAGES Figure IV-I. Location of Sampling Sites and Rain Gages. There are no sites numbered 3, 7, 8, 13, 15, 18, 20 due to a renumbering scheme. 1\

PAGE 29

Table IV-I. Location of Sampling Sites and Rain Gages. Sampling Station On-stream Sites 1 2 4 5 6 9 10 lL 12 ... 14 Detention Dl D4 Rain Gages L2 3 4 Location Haile Sink Hogtown Creek upstream of NW 34th St. Hogtown Creek downstream of NW 16th Ave. Possum Creek downstream of 16th Ave. Tributary to Possum Creek upstream of NW 24th Terr. Possum Creek downstream of NW 53rd Ave. Possum Creek upstream of NW 39th Ave. Tributary to. Possum Creek upstream of SRS232A (NW:31st Ave.) Possum Creek upstream of NW 34th St. Hogtown Creek upstream of NW 6th St. Tributary to Hogtown Creek upstream of NW 39th Ave. Hogtown Creek downstream of Howze Rd. (SW 20th Ave.) Hogtown Creek upstream of NW 23rd Blvd. Hogtown Creek downstream of N. Nain st. Hogtown Creek upstream of NW 29th Rd. NW32ud St. and 24th Ave. NW 39th Dr. and 14th Place. 10 m from creek 400 m south of 16th Ave. Northwood Sewage Treatment Plant Regional Airport (FAA) Bledsoe Drive, Hull Road (300 m east of 34th St.) (NOAA) 20.

PAGE 30

/'V f-J /. --I .. I ... ----. __ L __ =f"'. Jr ..... 1 ... :.... __ __ ...... <;:"-... -.. I ... _' ...... P . '. '. :'" 26"'. 11 :.... .. K ... I I .. OPEN DITCHES .......... 15'-30' TOP WIDTH -----> 30' TOP WIDTH Figure IV-2. Identified Point and Nonpoint Pollution Sources.

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Table IV-2. Identified Point and Nonpoint Pollution SourcesNumber of Storm Sewer Pipes Storm Sewer Pipe Diameter, (inches) Location 12 14 15 18 24 30 36 42 48 60 1 1 3 1 1 2 2 2 1 1 3 2 1 1 4 2 1 5 2 1 1 1 6 1 2 1 1 7 1 1 1 .. 8 2 1 9 10. 11* 12 13 1 14 1 .. ... 1 1. 1 '--,-.". 16 1 1 17 1 18 1 1 1 19 .... 3 1 .. L. 20 2 1 21 1 1 22 2 2 1 23 1 1 24 2 25 4 5 1 3 26 1 1 27 3 1 1 28 1 2 1 1 29 2 30 1$ 0.5 mgd effluent from Northwood Treatment Plant 22

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CURRENT FLOOD MANAGEMENT STRUCTURES DETENTION BASINS Basin Descriptions During the course of the study, eight detention basins were observed with respect to their efficiency as flood management devices (See Figure IV-3 and Table IV-3). Four of the eight detention basins were constructed as an aspect of subdivision development and were designed to handle the runoff associated with these areas. These basins are numbered D4-D7 for the current study. Basins D5, D6, and D7 have similar growth of cattail and other emergent species. During periods of no rain there is no flow through these basins, while basin D4 is located in-stream and consequently has flow when the creek flows. Basins Dl and D3 are hardwood hammocks modified to handle subdivision runoff. The outlet from basin Dl is often clogged with debris and/or sand and the area is often ponded for a period of days following heavy rains. A major discharge process is 1Vhile the trees in this basin exhibit no signs of stress as yet, long periods of inundation are thought to be detrimental to these spec:joes (Wharton,. 19-70). Basins D8 and D9. are natural depressions stream had .. A ditch has been constructed to carry runoff from the area south oL16thAvenue to basin D8. This basin is a broad, nearly level hardwood swamp with open water __ during periods of high groundwater.cBasin. depression with a well defined stream bed. -accepting runoff from surrounding lawns Ap;mp tornaintain water levels in the pond, and discharges to a:sLOw-flow:Lngwetlands. system-to the south. Pictures of Dl ,D3, D4,:BSand in Appendix A, along with photographs of three stream sampling loca.i:ions. ... Application of ,Sl--WIM: The (S/T) block of the EPA Storm Water J:.ianagement Model (Sm-1M) was utilized to mOdel the flow routing through two natural (Dl andD3)"andthree man-made (D4, D5 and D7) detention basins. Stage to-surface area and stage-to-discharge relationships were evaluated from the physical dimensions.o each basin, and are depicted in Figures B-1 through B-5 of Appendix B and Tables B-1 through B-5 of Appendix B. The results were used in SWMM to route hypothetical flood conditions through the units. The S/Tblock is capable of tracking DO, pollutants, and particle distributions through the basins and accounts for the processes of evaporation, settling and decay. Interested parties are directed to .the latest docu:qlentation for further information (Huber et al., 1980). The results of the SWMM flood-routing exercise are available for review but are not included in this report. Because of the lower than average during the study, there was no opportunity to verify the effectiveness of the ponds as estimated by Sm-1M; of over 100 attempts to gather such data, only 17 samples were collected VISUAL llIPACTS OF STORMWATER RUNOFF Based on observations during the field survey and past experiences these visual impacts of stormwater impact were noted: 1. Along the northeast reach of Hogtown Creek above 16th Ave and below 39th Ave, a black oily substance was observed along the creek 23

PAGE 33

N +:Figure IV-3. / ...... 1 Location of Stormwater Detention Ponds. \.

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Table IV-3. Location of Storrnwater Detention Ponds. Detention Pond Location D1 NW 32nd st. and 24th Ave. D2 SW 41st St. and 6th Ave. D3 11W 38th Dr. and 31st Place D4 N"w 39th Dr. and 14th Place D5 m-J 21st Dr. and 42nd Place D6 NW 21st Dr. and 43rd Place D7 NW 29th Stand 39th Ave. tJ-W 22nd St. and 14th Ave. N"w 31st Dr. and 9th Ave. 25

PAGE 35

substrate. Associated with this was an abundance of a black filamentous growth. The growth was hypothesized to be a form of bacteria which was capable of utilizing the oily substance. 2. There was a side slope failure observed in detention pond D5. It appeared that a combination of surface runoff and a high percentage of clay in the bank was the cause. 3. From personal observation, the amount of turbidity in Possum Creek near 16th Ave. has increased over the past 5 years. This was believed to be due to increased construction in the upstream region. 4. As Hogtmm Creek passes under N.H. 29th Rd., sediment loading has half-filled the 4 foot diameter culverts. 5. The presence of floatable materials characteristic of Syste.lliS was noticed near 34th St., after the confluence of Possum and.Rogtown Greeks. The high number of stormwater outfalls was believed .to be responsible for this. 6 North of the Northwood Treatment Plantthe headwaters of Possum Greek appeared to have a high turbidity level. A four lane limestone roadbed traversing the area was identified as the major contributor of sediment. 7. Well over one hundred junked shopping carts are in the creek bed behind the Gainesville Hall (north of NI\f 23 Ave.). 8, The level. a! litter, floatables, .garbage and refuse (e.g., cans, bottles, paper, auto parts) is high along most of the creek system, but is increased downstream of highway storm drains (e.g., NW 6 St., NW 23 Ave.,NW16Ave. ,1"w34 St.). 9. The ';vater in the creek is dark and the bottom not visible from its headwaters near N. Hain St. almost to 1\lW 6 St. There is also foam where the water flmvs rapidly. Presumably this is a result of the phenolic leachate at the headwaters. 10. Portions of the flood plain are used for dirt bike trails, with considerable damage to the soil surface (e.g., to the west of Hogtown Creek, south of SH 2 Ave.). Erosive potential during overland flow to the creek during storms is thus greatly increased. Since much of the flood plain is still privately owned, the City has no control over recreation and land use in those areas. 11. At several locations along upper reache,s of the Main Branch, construction has occurred very near the narro';v channel and steep banks of the stream, and slope failures have occurred. "Sea walls'l or retaining walls have not all withstood the erosive potential of the creek. 26

PAGE 36

SAMPLING NETWORK During the field survey, the rationale for selecting the sampling network was discussed. Known point sources such as the Northwood treatment plant were bracketed, as were stream confluences. Also, many sample sites were located adjacent to major roads in an attempt to document their effect. 27

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v. ECOLOGICAL SURVEY RIPARIAN COMMUNITIES As a supplement to the field survey approximately 100 color slides were reviewed by three plant ecologists from the Center for Wetlands at the University of Florida. These slides surveyed the sampling sites and the flood management. structures and were discussed with respect to: 1. type and age of ecosystem 2. dominant species 3 .hydroperiod From this meeting, the schematic in Figure V-I was compiled. As shown, the riparian communities of the creek are predominantly mixed hardwood flood The northeast branches originate in pine flatwoods and variciuswetland systems. The central reaches flow through mixed hardwoo&,hammockswhilethe southern downstream reaches pass through wet prairies "and the surface via Haile Sink. Table V I shows representative species. lists prepared from work done by Snedaker and Lugo (1972) on the ecosystems of the Ocala National Forest. Species included in have been observed in the respective communities along HogtownGreek. Table V-I. Representative Vegetation in Riparian Communities HixedHardwood.. Community -Length of hydroperiod 0-30 days Larel Oak Red J:v1aple Magnolia Durand Oak American HOlly Black Gum Sweet Gum (Red Gum) Loblolly Bay Pignut Hickory Sand Live Oak Iron Wood (Hophorn Bean) Loblolly Pine Flowering Dogwood Spanish Moss Wet Prairie/Swamp Coontail -Length of hydroperiod 220-315 days Cattails Naiad Spadderdock Fresh Water Wetlands.-Length of Pond Cypress Black Gum Wax Hyrtle Water Lettuce hydroperiod 290-365 Button Bush Holly Duck Weed days The type of ecological community present in an area is sensitive to the length of hydroper1od. This sensitivity is manifested by species alterations 'in areas of altered hydrology, documented in cases of both drainage and impoundment. Possible changes in the hydrologic regime attributed to increased urbanization could result in vegetation changes, with more tolerant species replacing present ones. For instance, land drainage will alter the communities in an "upward" direction in Table V-I, whereas increased flooding or impoundment can kill elements of the flood plain community and convert them to a wetlands or swamp. The combined effects of altered quality of the water has not been documented. 28

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N IJJ Figure V-I t MIL,E I II PINE FLATWOODS FRESHWATER, WETLANDS, ..... WET PRAIRIES MIXED HARDWOOD FLOODPLAIN Schematic of Riparian Communities

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w o o 1 I MILE I Figure V-2. Vegetation and Land Use of Hogtown Creek Drainage Basin From Brown, et al., 1977.

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AERIAL PHOTOGRAPHS As an alternative approach, results from a 1977 vegetation and land use study of the St. John's River watershed (Brown et a1., 1977) were obtained from the Center for Wetlands. The Hogtown Creek drainage basin is presented in Figure V-2. Table V-2 identifies the numerical classification system. The maps were prepared from infrared aerial photographs taken in 1971. 31

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Table V-2. Land Use and Vegetation of Hogto,m Creek Drainage Basin-Index to Figure V-2. Unit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20'" 23-;!; 26;" ,), "-I 28 29-;'; 3M 31* 32* 33 34 il Classification Openland Recreation Low Density Residential Medium Density Residential High Density Residential Industrial Mining Commercial and Services Institutional Transportation Utilities Improved Pasture Cropland Citrus Nursery Confined Feeding Planted Pine Clear Cut Other Grassy Scrub Sand Pine Scrub Sandhill Community Pine Flatwood Xeric Hammock Mesic Hammock Hydric Hammock Hardwood Swamp Riverine Cypress Cypress Dome Bayhead & Bogs Prairie Freshwater Marsh Rivers and Streams Lakes and Ponds -1, Description provided in Appendix D. From Brown et al., 1977. 32

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VI. QUANTITY HONITORING STREAM FLOW GAG INC Discharge from HOgtO\Vfl Creek is gaged by the U.S. Geological Survey (USGS) at S.W. 20th Ave in Gainesville, station number 02240954, utilizing a stage recorder. Data are published as part of Water Resources Data For Florida and are available for the period of record December 1971 to the present. Discharge was previously gaged at Newberry Road in Gainesville by the USGS, with data available for the period 1959-1974. Flows in Hogtown Creek are varying about the yearly average value of 21 cis (for the period 1972-1978). Values for minimum daily, maximum daily and average monthly flows in Hogtown Creek are shown in Figure VI-1. Variations in daily discharge from the basin are closely related to weather changes, with extremes corresponding to precipitation patterns and major storm events. The relationships between monthly average values of rainfall, evaporation and creek discharge are depicted in FigureVI-:-2. Evaporation over the basin was approximated as 0.8 times measured -paIL evaporation.WEATHER MONITORING The monitoring of meteorological conditions consisted of the collection of rainfall data from two stations within the basin and two stations outside the perimeter. Figure IV-l shmvs the location of these stations. Station Itlwas established 10 meters from the creek in the center of the basin. Stationff2 was located at the Northwood treatment plant and was maintained along :t-lith Station III by project personnel. Station if3 is the F .A.A. Flight -Service Station located at the Gainesville Regional Airport. Station:fl4 is part of the University of Florida Department of Agronomy weather station. D2.ily rainfall totals recorded at each station are presented in Figure VI-3 and Table C-l (Appendix C). The differences in magnitude and frequencies reflect the characteristic nonuniform density of basin rainfall. Individual event records for Station ill and #2 are available. Compared 'vith long term monthly means, rainfall during February through June was 26.4 percent (5.6 in) below avera.ge values. This lack of rainfall hiridered efforts to-gather wet weather data. particularly from the detention ponds With soil moisttlre conditions low, there was probably less runoff from pervious areas than in previous years. As monthly flows were not obtained from the USGS station which provided the flow histo.ries. il). Figure VI-l, there was no comparison to indicate that flows were proportionally lower than historical averages. 33

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7001 600r 1\ /1 \ I MAXIMUM DAlLY FLOW 1\ >Or .. /\ / \j 2001:-J \ /. \ t 50(-I "OLITUI v FLOW 1\ ..e 40 f M n .. _. 'j \ \ 20f I :r: I -V () !o t-(/) I o I 6): L :;} r MINiMUM DAiLY FLOW 41 "\ oL l--L! __ ----.d1 J F A M J J A s o N D TIME, months Figure VI-I. Minimum Daily, i1aximum Daily, Average Monthly Flmvs for Hogtown Creek From USGS Water Resources Data for Florida, 1972-1978. USGS Gage 02240954 at S.W. 20 34

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J F M A M J J A s o N D Ti ME, months Figure VI-2. Monthly Averages of Rainfall, Evaporation and Creek Discharges. Fr-omUSGS Hater Resources Data for Florida, 1972-1978. USGS Gage 02240954 at S.H. 20 Ave. Drainage area = 22.5 mi2 35

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LV 0\ 2.0 8 --r M AR r-p.. P 1;:-" __ 1.0 2.0. I I ,I, 4 ,,-.. .bq (..) c: :.:::. 1.0 :j 2.0 IJ... Z -' 2.0 o 1.0 1LI (!) z o 3 2 Figure VI-3. Daily Rainfall Totals, Gainesville, Florida, February-July, 1980

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VII. STREAM QUALITY M:ONITORING INTRODUCTION A monitoring program was established for Hogtown Creek to general ,water quality conditions. The program was designed to provide a data base for the evaluation of urban development upon the watel,:'shed. In stream stations and detention ponds were sampled on a basis, 'and synoptic surveys were conducted under low and high flow conditions. In addition, a detailed hydrograph and sampling program was undertaken for a rain event in January of 1980. A list of chemical and biological parameters sampled during the monitoring phase of the project is presented in Table VII-I. The parameters included nitrogen "and phosphorus species, TOC and BOD coIIUnon biological indicators as suggested by.DER in Section 17.3.09 of Standards, common cations and anions, and physical constituents. The breadth of analysis is fairly comprehensive in terms of water chemistry and should provide a good initial data :base for further studies. However, the proj ect was not undertaken with the purpose. of determining or not the creek meets all relevant standards for Ciass III (recreational) waters in the State of Florida. In particular. no measurements were_made for specific heavy metal and organic contaminan'ts that might be associated with urban runoff, and further studies would be required to assess the impact of urbanization on the levels of those parameters in the stream. Previous data concerning Hogtown Creek ha\re been collected by various agencies. The most :recent information was collected by the DER in late 1979 and early 1980 at four general locations. The data consist of conunon physical parameters in addition to some llut.rienta.nalyses. Several biological studies also have been conducted, one in 1979 (Crisman, unpublished data) and one in 1977 by the DER. A study concerning the problem of phenolic waste in the stream vlaS eonducted by the University of Florida (Nisson 1974). METHODS Sampling Sites Fifteen sampling stations were chosen for chemical and physical constituent analysis during both high and low flow conditions. These stations were chosen for their proximity to possible point source discharges, storm water outfalls or other contributing pollutant sources. The sites are identified in Figure 11-4. Possible point sources included secondary waste treatment plant effluent between sites 9 and 10, an aromatic hydrocarbon (phenolic) contributor between sites 14 and 21, and a 60 inch storm drain from the Gainesville Mall parking lot upstream from site 19. 37

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Three gaging sites (sites 2, 4 and 5) sampled for fifteen consecutive weeks, to determine mass pollutant loadings. Site 2 is located downstream of the junction of Possum Creek with the mainstream of the Hogtown Creek at NW 34 St. and Newberry Road, while sites 4 and 5 are located on the mainstream and on Possum Creek, respectively, where they intersect NW 16 Ave. Two detention basins were sampled concurrently with the three streams sites, ;c.ampJ..e siteD4 consisted of an in-stream detention basin, and was sampled at its effluent end. Site number Dl, an off-stream detention basin, was dryd'.1ring nine of the 15 weeks, and was sampled at its influent end, due to a recurring constriction in the effluent end. No flow measurements were attempted at sites D4 and Dl. These sites also are shown on Figure I1-4. Sampling and Analytical Hethods Samples were collected in clear plastic containers, except for coliform and streptococcus analysis, which were collected in sterile glass bottles, and chlorophyll a, which were collected in brown plastic bottles. The nitrogen and phosphorus series, along th TOC, were preserved with 40 mg HgCl?/L" AlL samples ,vere cooled to 3-50 upon arrival at the laboratory withiJitwo hours of collection in the field. Field measurements included pH with a Fisher model 1500 portable pH meter, conductivity with a YS1 model 33. S-C-T meter, dissolved oxygen with a YSI model 54 meter, visibility with a Secchi disk, and temperature. FIO\vT measurements Herelua.de1;;ith the use of an Ott current meter in conjunction cross sectional area measurements of the stream at the sample site. In addition, hydraulic calculations utilizing an existing broad crested weir located. at t-;"o were _used for The calculations were made uSlngthe equatlon tor such welrs (Q = CLH ) (Klng and Brater 1963). Analyses for BOD", coliforms, and streptococcus were begun immediately upon of the lab or in the of BODS' no later than 24 hours afLer sampllug. Turbldlty was measured agalnst known standards on a Hach model 2100A turbidimeter. TOC was determined \vith a Beckman Model 915 total organic carbon analyzer. Cations were run on a Varian atomic absorption spectrophotometer, with a hollow cathode lamp and flame atomization. Alkalinity and suspended solids were determined according to Standard Hethods (APRA (1976). Color was analyzed calorimetrically after centrifugation of samples on a Perkin Elmer 550 spectrophotometer at 420 nrn., and compared to standard chloroplatinate solutions. 38

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1 Table VII-l 1 Chemical and Biological Parameters Nutrients NH,-N '-f N03--N NOQ-+N0 2 -N Total-P Ortho-P Najor Ions K Na Mg Organic Toe BOD_ -) Biological Parameters Chlorophyll a (mg/m 3 ) Total Coliforms (colonies/lOO mL) Fecal Coliforms (colonies/lOO mL) Fecal Streptococcus (colonies/lOO mL) Physical Parameters Flow (cfs) pH D.O. Temp (CO) Turbidity (NTU) Alkalinity as CaCO Conductivity Transparency (em) Color (CPU) Suspended Solids -'-Units of expression in mg/L except where noted in parenthesis. Total Kjeldahl nitrogen was determined with a micro digestion method which entailed pipetting 10.0 ml of unfiltered sample into a test tube, addition of 2.0 ml of sulfuric acid reagent described in APHA (1976) and digesting on a hot plate for an average of 5 hours. The samples were then allowed to cool and brought back to volume with 10.0 ml de-ionized water and vortexed.Samples were left to settle out boiling chips overnight and then poured into AutoAnalyzer cups and capped. They were then analyzed against digested standards on a Technicon AutoAnalyzer II using the indophenol procedure, as outlined in Standard Methods 1976). Ammonium was measured by the indophenol procedure on the AutoAnalyzer in a fashion similar to the digested Kjeldahl nitrogen samples. Nitrate and nitrate + nitrite-N were analyzed according to the automated cadmium reduction procedure (U.S. EPA 1975), except that a cadmium wire was used for the reduction of nitrate to nitrite instead of a column of cadmium granules. Total phosphorus was determined by pipetting 10.0 ml of unfiltered sample into a test tube and adding 1.5 ml of 0.5 g/lOO ml potassium persulfate, 0.1 ml of 0.5 g NaCl/SO ml and 0.5 ml of 11 N H 2 S0 4 The samples were then vortexed and autoclaved for one hour at 15 psi. After cooling, 0.5 ml of 11 N NaOH was added to the samples and to standards that also had gone through the above process. Addition of 1.5 ml of combined molybolate-ascorbate 39

PAGE 49

reagent (APRA 1976) to each sample and standard preceded the measurement of absorbance at 880 nm. Filtered orthophosphate samples (soluble reactive phosphate, SRP) and undigested standards were analyzed in a similar fashion minus the preliminary digestion steps. Chloride and sulfate were run according to automated procedures in Standard Methods (APRA 1976). Chloride analysis used the mercuric nitrate method adjusted for use on a Technicon AutoAnalyzer II, while sulfate analysis was conducted with the methylthymol blue method, once again on an Auto P..nalyzer. Total coliform, fecal coliform and fecal streptococcus tests were performed ac::ording to Standard Methods (1976), with preparation of all samples completed within 12 hours of collection. An arithmetic average for the most readable colonies was determined. Duplicate plates were prepared for all samples. Chlorophyll a was determined by Standard Methods (APRA 1976), with the following. exception. The sample was shaken to insure homogeneity and then filtered through aO. 45 JIm filter with a syringe apparatus in lieu of centrifugation of the filter/acetone Illixture. Chemical-and Physical Characteristics of Stream Sediments Ten stream sediment samples were analyzed for particle size distribu-.. tion using'Wo'S. Tyler CO'.D. S. standard sieves. Samples were separated into three particle size ranges: >2000 :]Jm for gravel, >63 and >2000 ]Jm for sand and <63 ]Jill for clay. The, sediments were then dried at lOSee, after which the remaining analyses were performed. The sediment samples were analysed for total phosphorus by a modified persulfate digestion method (APRA 1976) in which 200 mg of well ground dried sample was digested and analyzed by the single reagent colorimetric method, using digested standards to prepare the standard curve. Total nitrogen was computed by comhining results for nitrite + nitrate and total Kjeldahl nitrogen. Nitrate + nitrite was measured using a sulfuric acid dissolution followed by colorimetric detection (U.S. EPA 1969). Total Kjeldahl nitrogen was determined by digesting a dried aliquot of sediment with sulfuric acid reagent (EPA 1969), and analyzing the digestate according to the method mentioned earlier for measurement of water samples. Metal analyses were run on a Varian Technicon model 1200 atomic absorption spectrophotometer following digestion in concentrated nitric acid. After ashing at 400C, the sample was redissolved in a nitric/hydrochloric acid mixture, heated :gently, cooled, and measured against digested standards (U.S. EPA 1969). Benthic Invertebrates Benthic invertebrate communities were sampled at 16 stations along Rogtown Creek. Station locations can be seen in Figure 11-4. Single grabs were taken in both a pool and a riffle area at each station, for a total of 32 samples. The importance of stream flow and sediment characteristics in the 40

PAGE 50

distribution of benthic communities has been discussed by Hynes (1972). Samples were taken with a 1etit Ponar Grab (Powers and Robertson 1967) with a sampling area of 0.022 m. Samples were washed in the field through a 0.66 mesh sieve to remove excess sediment. Remaining organisms were. preserved in 10% formalin and stained with rose bengal. Samples were sorted in a white pan in the laboratory and identified using both a dissecting and a compound microscope. Taxonomic references used in the identification of benthic invertebrates include Pennak (1953) and Edmondson 41

PAGE 51

RESULTS AND DISCUSSION A summary of the biological and chemical data collected on Rogtown Creek is presented in Table VII-I. The values represent means of all data for the parameters sampled at all 16 sampling locations over the 15 week field phase of the yroject. The parameters include the common nu trient species, TOC and BODS' common biological indicators, major cations and anions, and physical conditions. The breadth of analysis is fairly comprehensive and should provide a good data base for further studies. Weekly Sampling of HOgto1irD. Creek As described in the previous section on sampling methods, three in-stream sites were sampled weekly for 15 consecutive weeks. Site 5 is located on Possum Creek Branch at NW 16th Avenue. Site. 4 is also at NW 16th Avenue on the main branch of the creek, and site 2 is downstream of the confluence of the two branches at NH34th Street and University Avenue. Flow. Flowing water was present at all three sites during the entire sampling period" Flow data are presented in Appendix E, along with arithmetic means and standard deviations. Flow measurements at sites 2, 4 and 5 varied with antecedent storm activity, as expected (Figure VI-3). A high flow was recorded during the comprehensive sampling period on April 14; lowest flow: was recorded onr.February 27" The two tributaries (Sites 4 and 5) averaged 0.41 and 0.23 mJ/s alid 8.3 cis) respectively, and the downstream site (2) averaged 1.32 m-is (46.6 cfs). Thus about 50% of the flow at station 2 could be attributed to stream flow previously passing through stations 4 and 5, and the remaining \>1 apparently ,vas contributed by the adj acent watershed and other minor tributaries. A low lying poorly drained area (swamp) between site 2 and the upstream sites (Figure 11-3) could have a substantial positive impact on the flow at site 2 during dry ,"veather conditions. This area also may serve as a detention basin during periods of high flow, and this may further explain the differencebe:tween measured flo"7 at site 2 and the sum of the measured flows at the upstream sites. Flows were also calculated at site 2 using the3Y2ter level height above a broad crested weir and the equation Q = CLH (King and Brater 1963). The average calculated flow was approximately 18% greater than the average from curent meter readings, and higher percentage deviations occurred during storm flmv periods. Water height above the v7eir was very small and was estimated with a hand ruler;_ this most likely accounts for the slight discrepancy .!!.. The pH levels at the three stream sites averaged between 7.00 and 7.15, but showed considerable temporal variability, as well as some spatial variability on any given sampling date (Figure VII-l). All the values recorded for sites 2 and 5 were between 6.0 and 8.5 and thus are within the allowable range for Florida Class III waters. Site 4 had values slightly outside this range on two occasions (5.9 on March 4 and 8.7 on March 11). There is no evidence that these variances from the Class III standard were the result of cultural activity, and they apparently represent natural fluctuations in stream 42

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TABLE VII-2 Biological and Chemical Data Summary for Three Weekly In-Stream Sites. Parameter Temperature (C) Stream flm, (CFS) Turbidity (lTD) Transparency (m) Color (PC Units) Conductivity Cwmho!cm) Dissolved Oxygen BOD (S-day) pH Alkalinity (as CaC03 ) Suspended Solids Nl/-N 4 N02 -N TKN SRP TP TOC Ca Mg Na K Cl SO-2 4 Total Coliforms (MPN!lOOml) Fecal Coliforms (MPN!lOOml) Fecal Strep (MPN!100ml) (yg/l) Site 2 16.5 46.6 10.1 0.34 171 170 7.9 2.5 7.0 65 11 0.05 0.02 0.93 0.55 0.88 LI0 29 40 4.7 ..., r 1.0 8.3 13.6 14.6 31,200 510 600 1.5 Values reported in mg/L unless othen-Jise noted. 43 Site 4 17.3 14.6 9.8 0.21 202 172 7.9 2.4 7.2 70 11 0.06 0.05 0.92 0.20 0.46 1.31 33 34 4.2 7.8 7.9 13.1 15.7 34,500 2,660 980 1.0 Site 5 16.6 8.3 9.5 0.17 134 172 8.0 2.4 7.0 57 10 0.24 0.02 1.23 0.83 1.23 2.17 22 28 4.6 9.2 5.7 14.8 15.7 31,200 1,200 580 0.67

PAGE 53

-K ,.. H 8.4 I :::f ,.ar n \. i \ !' ::Co. 7.4[ /'\. ",\ / ,,\ .IA .... } ;/\ II \' i \ \ 7.2 I 1..-1' '1 i,. \ f / \ ...... I I -SITE 2 ---SITE 5 -'-'-SITE4 .\ I \ I\.",. -"".... ,-". ;1 \!I \ 6.8 / \\ t. \ / 'Vii \ / s.s t \, 1-.. / f\ J ........ / 64 1\ g 1\[ 6.0 l 5.8 __ _L_._...1 _L.____.L _L.___J. I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 WEEK OF EVENT Figure VII-1 pH vs. Weekly Sample Period 44

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pH. The pH values at the three sites generally were within a range of one unit on any given date. No correlation between flow and pH could be discerned for any of the three sites (r = 0.08, -0.08 and 0.11 for sites 2,. 4 and 5 respectively). Interestingly, there also was no correlation between stream pH and organic color levels (Figure VII-Z), in spite of the fact that color levels were high (albeit variable) and organic color is composed of acidic macromolecules derived from decomposition of vegetation. Dissolved Oxygen and Temperature. Dissolved oxygen levels during the 15 weeks of monitoring normally were well above the minimum level of 5.0 mg/l in the State of Florida for Class III waters. Concentrations averaged around 8.0 mg/L for the three stream sites (Figure VII-3), and the recorded concentration (4.9 mg/L) was the only value below the state standard. Higher values (near saturation) were evident in the early stages of the study, and concentrations exceeded 10 mg/L in some instances, reflecting the cooler temperatures at that time. The water temperature during the study was initially aroundlOoC7 and it warmed to around ZOC by the sixth week, (March 11). Temperatures in the low ZOC range were maintained from that point to the end of the study at all three stream sites. Transparency, Turbidity, Color and.Suspended Solids. Transparency was unrestricted to the streambed in all cases except during the extremely high flows measured on April 3, 1980. Hogtmm Creek is a rather shallow water course (usually < 30 cm), and transparency measurements have little significance under this condition. Turbidity reached maximum levels on April 3 (30, 41 and 46 NTUat sites 2, 4-and 5 respectively). At a given site, high to moderate correlations were observed between turbidity and flow rate. This trend would be expected, since particulate matter is more easilYZsuspended during higher flow conditions. Coefficients of determination (r ) for turbidity with flow ,\;qere 0.31, 0.74 and 0.76 for sites 2, 4 and 5, respectively. Overall, turbidity levels averaged about 10 NTU for the three sites over this sampling period. Although this average is relatively low for flowing waters, it is higher than values reported for non-urbanized rivers in northwest Florida. Values averaging between 1.5-2.5 mg/Lare connnon for the Suwannee, Steinhatchee and Aucilla rivers (USGS 1979), with a maximum values around 5.0 mg/L. The average of the low-flow turbidity levels for Hogtown Creek is 5.3 mg/L indicating that high flow was not entirely the cause of the relatively high turbidity in the Creek. Z Suspended solids had a surprisingly correlation with stream flow (r = 0.01) and only a fair correlation (r = O.ZZ) with turbidity. This suggests that the data on suspended solids are probably not highly reliable; the relatively low precision is a reflection of the generally low concentrations of TSS in the stream. Dissolved organic color also was correlated with flow rate (rZ = 0.55 for three sites). Overall, Hogtown Creek is a highly colored stream, and in that regard is typical of many streams in this region of Florida. The mean color level for the three sites over the field sampling period was 170 CPU, and values as high as 615 CPU were observed on occasion. Color also had a 45

PAGE 55

9.0 ----.----.----------., .. ----.-----'-:---'--. SYMBOL SITE r2 2 0.04 8.0 I 0 A.. 4 O.O! 0 5 0.01 I 0 0 Jo J. 7.0 f-0 0 0 0 0 o 530 .. J. +' 0 0' :r: 0 a.. 6.0 l-0 .. 5.0 4.0! I I I o 100 200 300 400 COLOR, pcu Figure VII-2 pH vs Color, Three Weekly Sites

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-..,J 12.0 r-, -----------------. 10.0 -...J 8.0 ........ 01 E 6.0 0 0 4.0 2.0 ....---.. 0-----0 SITE 2 "SITE 4 SITE 5 -.() --..--o (,' I I 1.1 I I 2 3 4 5 6 7 8 910 II 12 13 14 15 'WEEK OF EVENT Figure VII-3 Dissolved Oxygen vs Weekly Sample Period

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2 moderate correlation (r = 0.26) with turbidity. The color and turbidity correlation can be explained on the basis of runoff characteristics; storm water runoff should bring higher concentrations of suspended matter and leach more organic color from surrounding land areas than would be present in low (base) flow conditions. Major Ions. The four major cations (calcium, sodium, magnesium and potassium) were present in the relative abundance of 14-3-2-1, respectively (as meq!L). Individual listings of the data, along with average values are given in Appendix E. Values for the four cations were fairly consistent through the study period. Cation levels are a function of the surrounding geologic structure, as weathering processes dissolve and leach them from soils in the watershed and introduce them into the water system. The Rogtown Creek area is underlain by limestone and its surficial soils are sandy with very low cation exchange capacities. Under these circumstances, calcium would be expected to be the main cation. Calcium did nzt correlate significantly with either flow (r2 = ;' .12) or conductivity (r = 0.05). and sodiuID2 on the other hand, both c?r:related flo,: = 0.40; r (Na) =.0.31) and Wlth conductlvlty (r (Mg) = 0.48; r (Na) = 0.39). MagnesluID and sodlum were present in quantities composed to calcium; nonetheless, it appears that ions other than calcium control the flow-related conductivity levels. Alkalinity measuremeDts showed little difference between2the three sit.es and had a. significant correlations with conductivity (r = 0.49) and with flow (rL: 0,34). The anion ratio was 4-1-1 for alkalinity, chloride, and sulfate, respec..t.ively (all in meq/L). Thus alkalinity is the controlling anion in terms of conductivity fluctuations associated with flow in Hogtown Creek. Organic oxygen (BODS) 2.5 mg/L for all samples at tne three sltes. ThlS average lS ln the low range of data revie;;ved (l-Ieioe1 et al. 1963; Mattraw and Sherwood 1977; Wanielista et aL 1977; and Burton et al. 1979) for various urban storm water runoff studies. A high standard deviation (2.0 mg/L) relative to the mean value was observed in the data set. This could be accounted for by the correlation of BODS with flow (r = 0.36), which fluctuated tially. BODS was correlated moderately with color er = 0.48); i.e. variations in organic color explain about half the variation in BOD Because organic color itself is relatively refractory and has little BaD, the correlation is lilce1y to be a co-effect of flow rather than a cause of BODS' High flows export more particulate matter off the land, including both refractory organics (color) and biodegradable organics than2do low flows. As was stated earlier, color also correlated well with flow (r = 0.55). Average values of total organic carbon (TOC) for the in-stream samples ranged from 22.2 mg/L at site 5, to 32.5 mg/L at site 4. An analysis of variance and Duncan's mUltiple range tests for the three sites were performed on the TOC data, and it was found that Toe levels along Possum Creek (site 5) were significantly lower than those observed along the main stem of Hogtown 48

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Creek (sites 2 and 4). This suggests a source of TOC above site 4, which carried an impact in terms of TOC concentration as far as site 2. As expected, TOC was (moderately) with BODS (r= 0.38) and also ';vith total coliforms (r = 0.34). Nutrients. Nitrogen levels recorded for the creek fell within values reported by Wanielista et al. (1977) for storm water data, except for ammonium levels (x = 0.02 mg N/L) which were well below the typical values. Site 5 exhibited the highest concentrations of all nitrogen species, with ammonium-N, nitrite plus nitrate-N, and TKN averaging 0.24 mg/L, 0.S3 mg/L and 1.23 mg/L, respectively. This trend is to be expected. since site 5 lies downstream of a wastewater treatment plant effluent on Possum Creek. The swampy area upstream of site 2 may have been partially responsible for the lower levels of nitrogen obserJ"edat that site, although the levels remained somel;vhat high, especially nitrite plus nitrate-N (0.55 mg/L). This level is similar to the average concentrationofthis parameter (0.48 mg/L) in urban stormwater runoff from south Florida (Hattraw and Shenvood, 1977). Temporal variations for NO; plus NO;-N and TN.'! over the 15 week sampling period are presented in Figure VII-4 and VII-5, respectively,til1d show a high variation for both parameters at sites 2 and 5, and for TKN at site 4. Nitrate plus nitrite had the highest overall correlation of the measured-nitrogen species with flow, but even in this case, f12w variations explained only-a small fraction of the variance in concentration (r Mass loadings were calculated for the nitrogen species at the three weekly sample sites. Values for total Kjeldahl nitrogen, nitrate + nitrite and ammonium nitrogen are illustrated in Figures VII-6, VII-7 and VII-S ii The 11igh.-durirlg"tv-eek. 9 contributed significantly to the mass loading rates of all species. Site 2 also had a conspicuous peak for nitrate + nitrite loading during week 11, due to a relatively high flow and a moderately high concentration. These figures give an indication of the effect of localized storms in the Hogtmm Creek drainage basin on downstream loadings of the various nitrogen species. Ona relative basis, the rain event during week 9 had a greater impact on loading of TKN (Figure VII-6) than on either ammonium or nitrate + nitrite loadings. A period of approximately one month of negligible rainfall (Figure V-3) preceded the event of April 2-3 (week 9), which enabled a typical Hfirst flush" rainfall event to occur. Insoluble nitrogen (TKN) exhibited a large peak in mass loading at that time, and a smaller peak occurred two weeks later following another rain event. Insoluble organic material did not have as much time to accumulate in the watershed prior to the occurrence of the second storm. Soluble nitrogen (nitrate plus nitrite) was not influenced by the variations in storm intervals. Ammonium concentrations ,,,ere near detection limits during the second event. Total phosphorus levels at the three weekly sampling sites ranged from an average concentration of 1.08 mg/L at site 2 to 2.17 mg/L at site 5. These values are high compared to TP concentrations reported by (1952) for small humic-colored creeks ( 0.41 mg!L) in Florida, and they even are slightly higher than the levels he reported for streams not draining phosphate formations but receiving sewage (0.84 mg!L). However, Odum (1952) also reported TP concentrations for sites in Hogtown Creek that are analogous to sites 2, 4, and 5 in this study, and his results (1.4, >1.0, and >2.0 mg/L, respectively) are similar to levels found in this report (Table VII-2). Thus in terms of 49

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111 o ..J ,2.0 Z I Ol E ... til o z +.., 1.0 o Z ----"'-S I TE 2 SitE 4 SITE 5 o 2 3 4 5 6 7 8 9 10 II 12 13 14 15 WEEK OF EVENT Figure VII-4 Nitrate + Nitrite vs. Weekly Sample Period

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I..n I-' -1 ......... 2.0 Ol E ... z 1-1.0 0.0 .: I: t 3.9 ------/ .......... ..................... -..... '/ ..... WEEK OF EVENT -,. SITE 2 0-0 SITE 4 ". --.. SITE 5 i Figure VII-5 TKN vs Weekly Smaple Period

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80 SITE 2 SITE 5 SITE 4 36.3 31.8 27.2 22.7 13.6 2 3 4 5 6 7 8 9 10 II 12 13 14 15 WEEK OF EVENT Figure VII-6 TKN load VB. '\feekly Sampling Period 52 ..

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... Z I I I 10 l-I SITE 2 9 -_._;: I a 7 s r II z 5 'I /\ uS I I I \ 4 i j\ A If \ -4.5 -14 1 3.6 3.2 Z 2.7 ()JO I Z o f\J 2.3 I Z t8 1.8 "'" V \\ ,I \\ I i \ w 3 /"-,,, I \ / \ "J I \ ..... L \ I \ / \ Z 2 \.) I \ 1 t \v/ ; I /p \, \\ / 0.45 "I ..... .r',;' '!l...., 1/ .... '\ f -#' ,'1 ..4 '-. O I ,,;r.-. 'Ill __ l -.r: __ --,,--I _...1l 2 3 4 5 6 7 8 9 10 II 12 13 14 15 WEEK OF EVENT Figure VII-7 Nitrate+Nitrite load vs. Weekly Sampling Period 53

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L.J::. "-0 Z I J!) ...L Z I i -"I-} SITE 2 SITE 5 i SITE 4 2.er j I 2.61i I I I 2:4r I 2zL \ I I ?l I I ..... I I \ /.8, I \ i 1.6t-I \ \ I I \ !2L J i I / \ I 0.61-1'\ I I \t 0.4 I I I ," /* ""y" 0 I I 2 3 4 5 6 7 a 9 10 II 12 WEEK OF EVENT Figure VII-8 Ammonia load vs Heekly Sampling Period 54 [.45 1.27 1.09 z I 0.9/ OJ Z ;K" to 0.73 "-::r 0.54 0.36 0./8 13 14 15

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TP, cultural disturbance in the watershed seems not to have worsened since 1952. Average levels of soluble reactive phosphorus (SRP) ranged from 0.46 (mg/L) at site 4 to 1.23 (mg/L) at site 5. Concentrations of both SRP and TP were consistently highest at site 5 (with one exception in each case) over the 15 weeks of routine sampling (Figures VII-9 and VII-lO), and site 4 generally had the lowest concentrations of both species. Arguments porting these trends are analogous to those for nitrogen; site 5 is downstream of a domestic wastewater discharge and little opportunity exists for natural treatment processes to remove phosphorus between the discharge point and site 5. Mass loading calculations (Figures VII-II and VII-12) indicate that a storm event following a period of no rainfall affects TP more than SRP. This trend follows the trends noted for the nitrogen species. 2However, little correlation of phosphorus with flow is evident (r (SRP) = 0.12, r (TP) .-= 0.15). Biological ParfJmeters. Chlorophyll a levels measured in-jtream rarely rose above 2.0 mg/m. Site 5 3had the lowest average (0.7 mg/m ), while site 2 averaged a-high of 1.5 mg/m. It is obvious, both from these data and from visual. inspection of Hogtown Creek, that planktonic productivity is low in the Moreover, the general absence of macrophytic vegetation in the stream indicates that overall the stream has low autotrophic potential and that it functions as a heterotrophic ecosystem. The levels of chlorophyll in the streamare,not surprisiI:lg,' given the short hydraulic residence time of the stream. Furthermore, HOgtovlil Creek is predominately shaded and colored, thus hindering the growth of algae, even on sediments where they othenvise would most likely be found. Total coliform levels during the weekly sampling program often exceeded the Stateo Florida Class III water quality standard of 2400 colonies/lOa mL at all three sites. Nearly 60% of all measured values exceeded the standard, and sites 2 and 4 exceeded the standard for 70% and 90% of the samples taken, respectively. TC levels at site 5 were above the standard only about 20% of the time. Chlorination of the wastewater effluent above site 5 could have led to the lower values found at that site; general (overall) conditions of the watershed are better represented by data collected at sites 2 and 4. The simple average levels of TC were similar at the three sites &about 3.2 x 10 colonies/lOa mL), but the high standard deviation (6.5 x 10 ) indicates a highly skewed distribution and severe contamination in some samples. Geometric means are better indicators of central tendency in skewed populations; these means for TC at the three sites are 4175, 8575 and 1163 colonies/lOa mL for sites 2, 4 and 5 respectively. Little correlation was observed between TC levets and flow (r2 < 0205) or other physical parameters, such as temperature (r = 0.10) and pH (r < 0.05). The Class III standard for fecal coliform (800 colonies/lOa mL) was exceeded in over half of the samples taken in the weekly study. Site 4 exceeded the standard in all of its samples and had fecal coliform to fecal streptococcus (FC/FS) ratios above 4.0 in over 80% of the samples. Sites 2 had fecal coliform levels above the Class III standard about 30% of the time and it had an FCjFS ratio above 4.0 one third of the time; surprisingly, the FC/FS ratio for site 5 was below 4.0 for all samples (in spite of the fact that this 55

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--. SITE 2 0,-0 SITE 4 ..--..,0 SITE 5 I 2.0 .....J ........ a. I \.r1 0) 0'\ E .-OV (l. 1.0 I 0 0.00 2 3 4 5 6 7 8 9 10 II 12 13 14 WEEK OF EVENT Figure VII-9 SRP vs. Weekly Sampling Period

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V1 '-J -J ... Q2.0 .f en E ..-i o 1.0 a... -----------------. 1 4.89 A 5.11 0 04.1::\ ilt-... 0'---0 '----.,. SITE 2 SITE 4 SITE 5 h 0.0 6 2:3 4 5 6 -7 8 9 10 1'1 12 13 14 d5 WEEK OF EVENT Figure VII-IO Total Phosphorus vs. Weekly Sample Period

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20 r SITE 2 9.08 ---SITE 5 I 18 t-I -'-'-SITE 4 8.17 7.26 s... 14 ..c '-...0 po 6.36 0-I \ I OV a.. 12f \ 5.45 I I 0 0 I \ I -0 ... W 10 I\ I 4.54 .f::>.O I I :c l \ .. -0 a.. I I (f) i It 3.63 7' 0 I \ .to :r: '1\ ......... 6 \ I I I \ ::r n-... 0 i \, ::c f \ 2.72 i-I/ \ 0::: I \ 0 I \ If \ 1.82 !J \ I If \ i' if \ 2 '" / if \ 0.908 \', / \ if 'v/ / \ ............ -\ ::::/-, --. __ .-' 'I '-..;::. __ :.=' 0 I -4 WEEK OF EVENT Figure VII-II SRP Load Weekly Sample Period 58

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4 'is I 3-1 SITE 2 16 or-SITE 5 SITE 4 I 13.6 30!-I I I '-I :I: I ...... 2Sr .J:J 11.4 .J 0.:-, I I -f l-I I I' (f) => 20L 9.1 0::: I =" 0 c.O ::c' I I ........ 0... ::r ro I .., Q ..... 06.8 .J
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was the closest site to the sewage effluent discharge point). The fecal coliform to fecal streptoccous ratio (FC/FS) can be used to indicate the source of fecal contamination (Burdner and Winter 1978), withratios above 4.0 being predominately human in nature and those below 1.0 indicative of agricultural sources. Values betwezn 1.0 and 4.0 are indicative of mixed Neither fecal coliform (r < 0.05) or fecal streptococcus (r = 0.13) levels correlated significantly with flow. Overall, two separate areas seem to exist in the Hogtown Creek watershed in terms of coliform levels. Possum Creek (site 5) exhibits almost acceptable total coliform levels, with the apparent source of fecal contamination being predominantely non-human in nature. The main branch of Hogtown Creek, however, (site 4) shows very high total coliform levels, with fecal contamination primarily of human origin. Coliform levels at site 2 were in an intermediate range, reflecting the mixing of the two branches upstream. It is likely that chlorination of the domestic waste effluent above site 5 led to a depressed level of fecal contamination there; reasons for the high levels of coliforms at site 4 are not immediately obvious. A further sampling program is needed to establish the source of this contamination. Statistical Aualysisof Weekly Sampling Data. A brief statistical analysis was conducted on the weekly sampling data for the three stream stations using the Statistical AnalYSis System (SAS) program. One-way Analysis of variance and Duncan multipl.erange tests were used to determine whether statistically significant d,i:fferences exist in mean values for selected variables among the three s1:tes (2, 4 and 5) in weekly sampling program. The Duncan test was used for TKN, T-P,flow, turbidity, BOD, TOC, suspended solids and color. Of these-parameters, only two (flow and TOC) had statistically different values (Table VII-3). As expected, flow was higher at site 2, downstream from both sites 4 and 5. TOC was statistically higher at sites 2 and 4, and the cause of this probably is a TOC source upstream on the main branch of Hogtown Creek. Weekly Sampling of Detention Basins Two detention basins were sampled weekly, sites Dl and D4 (Figure 11-4). Site D4 is located hetween a cluster of residential homes, and serves as the in-stream detention basin. Eleven samples were collected from this site at its effluent end. Inflow is from a small tributary that eventually enters the main stream of Hogtown Creek below site number 2. Site Dl is an off-stream detention basin which serves as a rainfall catchment for a small subdivision and empties into Possum Creek downstream of site 12. Six samples were obtained from this site; for the majority of the study period no flow was observed from this basin. Four of the samples were taken during high flow conditions, and two samples were taken under low:-flow (background) conditions early in the study. The limited number of samples collected at site Dl, and the low-flow conditions under which two of the samples were taken make a thorough analysis of data for this site speculative. Flows were not measured at either site as part of this project. Physical parameters. Overall, the detention basins exhibited better water quality than the in-stream stations. Temperatures were somewhat higher 60

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TABLE VII-3 Duncan Multiple Range Test For Selected Varib1es Parameter .Site Mean N Grouping TKN (mg/1) 5 1.233 13 A 2 0.935 11 A 4 0.916 11 A (mg/!) 5 1. 769 14 A 4 1.308 11 A 2 1.076 12 A Flow (cfs) 2 46.62 15 A 4 14.58 13 B 5 8.34 14 B Turbidity (JTU) 2 10.09 15 A 4 9.76 15 A 5 9.53 15 A BODS (mgll) 2 2.553 8 A 42.444 9 A 5 2.365 8 A TOC (mg/1) 4 32.52 12 A 2 29.16 13 A 5 22.23 14 B Suspended Solids (mg/1) 2 11.28 13 A 5 10.85 13 A 4 10.45 13 A Color (units) 4 202.2 13 A 2 171.2 13 A 5 134.2 13 A Alpha Level = 0.05 Means with same letter are not significantly different. 61

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in the basins, reflecting large surface area to volume ratios. Dissolved oxygen levels were substantially lower in the basins than in the stream, in part reflecting the temperature difference and semi-stagnation at times at site Dl. Dissolved oxygen levels at sites D4 and Dl averaged 7.0 mg/L and 4.7 mg/L, respectively. A minimum of 3.2 mg/L was measured at site Dl on March 11, 1980. Site Dl did not meet the Class III water quality standard of 5.0 mg/L on five of the six sampling dates. The pH of the two detention basins fell below the Class III standard of 6.0 once, (D4 == 5.9, Dl = 5.2) on February 27, 1980, but there is no evidence that this variance is a result of cultural. activity. The average pH at the detention basins was 6.5 (Dl) and 7.6 (D4). The bottom was visible on all sampling dates in the detention basins, and hence Secchidisk transparency could not be measured. Lower turbidity and suspended solids data for the detention basins compared to the stream sites indicate that the basins do operate as settling areas for particulate matter. Turbidity averaged 2,8 NTU CDI) and 1.9 NTU (D4) for the detention basins, while the three in-stream sites averaged 9.8 NTU. If the three in-stream samples can be equated to general in-stream water quality, these results are equivalent to a removal of 70-80% of the turbidity in the detention basins. Suspended solids concentrations averaged 3.6 mg/L at Dl and 3.4 mg/L at D4. The three in-stream samples averagedlO.9 mg/L, which also is equivalent to about 70% removal of suspended solids Ior the detention sites. Color averaged 50 CPU at both detention basins, which is significantly lower than the average of 170 CPU observed at three in-stream sites. Conductivity correlated well with alkalinity (r = 0.81) at site D4, which is analogous to correlations discussed earlier for the in-stream samples. An insufficient number of data points are available for site Dl for meaningful statistical analysis. Conductivity at Site D4 averaged 187 1_llnho/cm and Dl averaged 157 these values are comparable to the average of 170 at the three in-stream sites. Major Ions. Average anion and cation concentrations for the detention basins were near or below the average of the three in-stream sites. Alkalinity sulfate, chloride, sodium and calcium levels at site D4 were approximately the same as the average in-stream values, whereas all major ions had lower average concentrations at site Dl. Average values are listed at the end of Appendix E for the individual sites. As in the stream samples, calcium and alkalinity were the dominant ions (30 mg/L of Ca and 55 mg/L (as CaC0 3 ) of alkalinity for both Dl and D4). Organic Natter. Average levels of biochemical oxygen demand (BOD) at basin D4 were similar to those measured in-stream (2.4 mg/L) >vhile basin Dl had a slightly higher 2average (3.0 mg/L). BOD correlated significantly with color at site D4 (r = 0.79), which follmvs the trend discussed earlier for the in-stream samples. Total organic carbon (TOC) levels in the detention basins were approximately 50% lower than those reported for in-stream samples (D4 = 14.8 mg/L, Dl = 15 6 mg/L). This can be related partly to the settling of suspended particulates in the quiescent water column and partly to the reduced color levels found for the detention basin samples. BOD and 62

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TOC did not directly correlate at site D4 (r2 < 0.01); the small number of samples available for site Dl precludes meaningful correlation analysis for that site. Nutrients. Nitrogen and phosphorus concentrations in the detention basins were generally lower than those encountered in-stream. Total Kjeldahl nitrogen (including particulate nitrogen) was lower by averages of 22% and 40% at sites Dl and D4, respectively. This can be attributed to settling. However, dissolved nitrogen species, such as ammonium, nitrite andnit;.rite plus nitrate also were lower. TP and SRP concentrations exhibited similar characteristics. TP was 45% CDl) and 72% (D4) lower than in thein-stream samples. In all cases, nutrient concentrations were lower at basin D4 than at Dl. This could be due to a large standing crop of macrophytes in basin D4, which probably was actively assimilating nutrients. Biological Pjrameters. Chlorophy11 levels in the two detention basins averaged 4. I mg/m at Dland 1. 75 mg/m at D4. These v31ues are well below the level associated with eutrophic conditions (10 mg/m ) in lakes. Total coliform levels for two samples at basin Dl (geometric mean = 6700 colonies/IOO mL) were ,veIl above the state standard for single samples (2400 colonies/lOO TIlL). Basin D4 had total coliform levels above the standard (geometric mean = 2650 colonies/IOO mL). Fecal coliform levels for 8 samples collected at basin D4 had a geometric mean of 172 colonies/IOO mL, well below the Class III standard of 800 colonies/IOO I!1L). One fecal coliform sample collected at basin Dl indicated a high level of contamina.tion (1480 colonies/ 100 mL). The source of contamination at basin D4 appeared mixed in that FC/FS ratios ranged from 0.008 to 5.8; the single FC/FS measurement at site Dl (Fe/FS 18.0) indicated contamination from human waste. Overall, the biological quality at basin D4 was acceptable or near-acceptable, but based on the limited number of samples at basinDl, this site appears to be highly polluted. SUITilllary of Heekly Sampling The water chemistry in Rogtown Creek is not what one would call descriptive of a creek in a "pristine" condition. Levels of turbidity and phosphorus discussed earlier compare the water quality closer to urban stormvater runoff than to naturally occurring stream flow. This must be expected, in light of the development of commercial and residential areas in the watershed. A contribution of domestically related parameters, such as nutrients, cations and solids, along with the contribution of commercially related organics, color and turbidity is evidenced by the weekly sampling portion of this study. Further monitoring of the water chemistry of Rogtmvn should be done, with the addition of water quality data in the form of parameters such as oil and grease, heavy metals and specific organics, in short, the Class III State Standards. Following this, more accurate information of the point sources can be evaluated and preventive action can take place. 63

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Surface WFter Synoptic Sampling Two comprehensive (synoptic) surveys of Hogtown Creek were undertaken during the study to obtain detailed information on spatial variations in stream water quality under both low-flow and high-flow conditions. A total of 15 in-stream and detention basin sites (Figure VI-I) were sampled within a 6 hour period on April 3, 1980, immediately following a 5 em (2 in) rain-fall event.. These sites were chosen according to the relative proximity of possible point source (storm drain) discharges. The same sites were sampled again on May 6, 1980, during low flow conditions that followed a two week period of no rainfall. Thus the two sampling events can be equated to a rainfall event analysis versus background data. The relative flow measurements of the two periods on the average differ by greater than a factor of ten in Water quality. conditions during the two surveys provide some interesting,comparisonsof flow-related trends. These trends and spatial trends along the stream comprise the majority of the following discussion. All data are presented in Appendix E. PhysicalParameters. Flow measured at sites 4 and 5 contributed almost 80% of the total_flow measured at site 2 for the low flow event, but only 45% during the high flow. This difference reflects the effects of the low lying area (swamp) above site 2.J-l-ater temperatures averaged 22C for both synoptic surveys. Detention basin D4 maintained a slightly higher than average temperature on both dates (26C), -and site 1 was higher during the high flow sampling (28C). HogtownCreek at site 1 overflowed its banks during high flow, which resulted in a large surface-area to volume ratio at that time, causing a slightly elevated temperature. Relatively little variance in pH was noted for the 15 sites during either sampling period. and;'.the range in individual values was one pH unit (6.7 to 7.7), except for a single higher value (8.4) at site D4 during high flow. Dissolved oxygen (D.O.) levels fell below the State Class III standard for the in-stream samples only at sites 14 (4.7 mg/L) and 17 (4.4 mg/L) during the low flow sampling. Site 14 is directly downstream of a known phenolic contributor on the ,main stem of Creek (Figure IV-I), while site 10 is directly do"mstream of a domestic 'wastewater treatment plant effluent. Dilution of these samples with runoff could easily have masked low D.O. levels during the high flow event. Detention basin Dl had a low D.O. during the high flow event (3.7 mg!L). The average suspended solids levels varied by a factor of 2.6 for samples collected on the separate dates. The high flow event averaged 21.2 mg/L, while baseline, (low floW) measurements averaged 8.2 mg/L. Spatial variations were somewhat inco:nsistent for the two periods (Figures VII-13 and VII-14), but suspended solids levels generally decreased with distance downstream. Turbidity measurements also were substantially higher during high flow (x = 21.6 NTU) than during low flow (x = 10.6 NTU). Variations downstream during high flow indicated few trends (Figure VII-IS), except for lower turbidity levels in the far downstream samples. Baseline measurements were generally uniform downstream, but samples collected along Possum Creek were slightly higher 64

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0\ \..1l .--._-... _-_ .. .. 1": __ i_ 8J 4/'3/80 72[ -HOGTOWN / --POSSUM / E 64 -'-'-THISUTAR'IES '/ .. CJ)5G CJ) / en 48 I 0 / _J 4 0 I CJ) o 32 W 2 24 W 0.. 16 CJ) :::> (f) 8 0 5 04 4 01 6 12 19 II 161014 9 SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-13 Suspended Solids vs. Distance UpstreamHigh Flow Sampling 4/3/80 Distance between stations not to scale. ---------,----_. ---.-----'.

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30 ..J "-O'l E u) (J) .. (J) 20 0 0\ 0\ -1 0 (J) 0 W 0 Z 10 W 0(J) ::> (J) 0 5/14/80 A_ -HOGTOWN --POSSUM _0_0-TRIBUTARIES -/ I \ / \ I \ / \ \ ./ \ \ IX. \ "_ I\.\ '-'-.,.... \ '-------, '_. ." I <""" ..a\ -'-'-' "-. '...y' \ \ 17 2 5 0440161219 II 161014 SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-14 Suspended Solids vs. Distance Upstream Low Flow Sampling 5/14/80 Distance between stations not to scale, 9

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50 45 40 :::J 35 +-'......, Q'\ >= 30 '-J r-0 25 ill 0:: => 1-20 15 10 5 0 ___ .. ____ .. __ ..--._' __ T.., ...... .. ____ OUOI __ ........... _. __ ... """ ... _U'"..._, 4/3/80 -. -HOGTOWN -_.POSSUM r i _.-.TRIBUTARIES \\ l( 1\ I f \\ I '. t-., ........ \\\ ,'/ ............... \ / 'e \ \ 17 """'" ......... 2 '-. ....... ........ \ \ / \ I \ ,'Y /\ \ i / \ \"j \ \!/ \ YJ ........ 5 044 DI 6 12 19 II 16 [0 14 SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-IS Turbid'ity vs. Distance UpstreamHigh Flow Sampling 4/3/80 Distance between stations not to scale. 9

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than those along the main stream (Figure VII-16). Turbidity at site 14 was significantly higher than that at the other sites during low flmv. In both the detention basins (D4 and Dl) had relatively low suspended solid and turbidity levels, as would be expected. Visibility was restricted during the storm-related sampling and the bottom was obscured at many sites for the only time during the enitre study. Visibility averaged less than 8 in. (20 cm.) for the sites where the bottom was not visible. The turbidity and suspended solids during th1s time give an indication of the degree of wash-off from the adjacent watershed. The level of color was almost three times higher during the high flow synoptic (370 CPU) than during flow (135 CPU). In both surveys site 14 exhibited the highest color level. Dilution effects can be seen for color (Figures VII-17 and VII-:l:8); where flow from other tributaries lowered the color levels "t-lith distance downstream from site 14. The fact that occurred during both low and high flow periods suggests a non-flow related contribution of color above site 14. In both synoptics, color measurements along the main branch of Rogtown Creek were higher than those for Possum Creek, which further substantiates the presenceofa point source on the. main stream 2-Major Ions. The major cations (Ca, Mg, Na, K) and anions (RCO;, S04 Cl ) were generally lower in concentration during the high flow synoptic than during the low flow. Conductivity, a general measurement of ionic str.ength, -';vas during the high-flow sampling, averaging 130 jlmho/cm in the latter survey and 210 Imilio/cm in the former. This trend maybe attributed to lower dissolved solids levels in rainfall and accompanying the high flow conditions. The low flow synoptic yielded higher conductivity levels than the overall study average (170 limho/cm although in general all major ions (except alkalinity) were near their averages for the entire study. Nutrients. During baseline flow, high levels of nitrogen and phosphorus were evident along Possum Creek, beginning at site 10. Concentrations of ammonium (0.5 mg/L) nitrate (0.25 mg/L), and SRP (1.7 mg/L) were especially high at site 10, (downstream of a wastewater treatment plant effluent). Concentrations of these species generally decreased with distance downstream. Similar conditions were not in evidence during the high flow period. Dilution of the treated wastewater with run-off caused this effect. In general, higher concentrations of dissolved inorganic nitrogen and SRP were evident during the low-flow period than during high flow. Organic forms of nutrients (TKN minus Nfl3 TP minus SRP) generally were higher during the rainfall associated synoptic, due to washoff of terrestrial organic detritus (litter). Average levels of organic nitrogen (1.02 mg/L) and organic phosphorus (0.45 mg/L) during high flow, however, were only slightly higher than the overall average for the study (TON = 0.81 mg/L, org P = 0.41 mg/L). Low flow TON averaged 0.60 mg/L and org P averaged 0.37 mg/L. Organic matter. Biochemical oxygen demand (BOD) measurements made during the second synoptic (low-flow conditions) indicated rather uniform concentrations with distance downstream (Figure VII-19) except for two 68

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::J +-C]\ '--' \0 )-!' I-0 OJ 0::: :::J I-50 45 40 35 30 25 20 15 10 5 0 5/14/80 -HOGTOWN --POSSUM -:-.-.-TRIBUTARIES -....,..--,. __ ._.. __ ._--_ .. _. __ .......... ---, ?-----/--.... / '\(/ / ". '" .:..----/ -.-.-. -'-. ... ...... -'-'17 2 5 04401 6 1219 II 161014 9 SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-16 Turbidity vs. Distance UpstreamLow Flow Sampling 5/14/80 Distance between stations not to scale.

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-...,J 0 (/) ..-'c ::3 .. a:: g 8 700 630 560 490 420 350 280 210 140 70 0 r-.... '---.-------------4/3/80 -HOGTOWN --POSSUM _._.-TRIBUTARIES ." / // f / / / I __ -< i / .\.e / ././ \ / ././ \ I /,/ \ i / .,/,/' \ i / \ / ,1/ VI 17 2 5 D4 4 01 6 12 19 II 16 10 14 I / 9, SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-17 Color vs. Distance UpstreamHigh Flow Sampling 4/3/80 Distance between stations not to scale.

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500 400 ...... 1 .$ 3'00 1-' C ::J .. a:: 0 -I 200 0 U 100 o '---.--------:.----.-.----'-.. --'--.-.".------.,-'-:.-' ------,----.-'-----------,----1 5/14/80 -HOGTOWN _._POSSUM .. -.TRIBUTARIES ..---\ A ,,/' \ / .......................... \ / ....... /' '\" ..... / \. .'.', \ ............... ......... _----<. \ ....... "'b ....... '-'-". ............... ... SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-IS Color vs. Distance Upstream Low Flow Sampling 5/14/S0 Distance between stations not to scale.

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"-O"l E I.C) 0 ._J g
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sites. The elevated BOD concentration at site 10 (5.5 mg/L) may have been the result of insufficient chlorination at the wastewater treatment plant, while an elevated BOD level at site 14 could have been the result of organics contributed upstream of that site. The detention basins had higher BOD levels (19 mg/L) than the remainder of the stream (average of 1.0 mg/L excluding sites 10 and 14) for the low flow synoptic. Total organic carbon (TOC) concentrations_during high flow. were higher (average of 27.6 mg/L) than during low flow (average of 21.8 mg/L) again to reflecting runoff of detritus associated with the rainfall event. Spatial variations with distance downstream (Figures indicate that Possum Creek had a much lower level of TOC during both synoptics than did the main stream. Runoff contributed to a high Toe level at site 16 during the April synoptic (site 14 not reported), while the maximum TOC concentration in the low-flow (May) synoptic was measured at site 14. Lower TOe levels were observed during both synoptics in the detention basins (x = 12.8 mg/L) than for the in-stream samples. Along with the color results, the results on TOC indicate the presence of organic contamination above site 14, both as colored and non-colored dissolved organics. -Biological Para.-rneters. Total coliforms levels were extremely elevated (geometric mean-= 12,000 coionies/IOO ml) during the high flow synotpic, aswerefeca1-coliform levels (geometric mean = 3300 coionies/IOO ml). Wash-off of detritus contributed to these elevated levels, and a priori a mixed source of animal and human contributors might be expected. Slightly more than half of the samples had FC/FS ratios below 4.0. Water quality was-much better in terms of biological activity during the low flow s-ynoptic. Although the geometric me.an (2600 colonies/lOO mI.) for total coliforms was above the Sta.te Class III standard, only three of the 14 individual samples collected exceeded the standard. Fecal coliforms averaged higher than the State standard (geometric mean = 1100 colonies/lOO ml), and Fe/FS ratios were indicative of human waste (greater than 4.0) in slightly over half of the samples. Cluster Analysis of Synoptic Data. A multivariate statistical procedure, cluster analysis, was used to group the 15 synoptic stations according to their chemical similarity based on six common water quality parameters. The SAS routine, CLUSTER was used for this purpose and the parameter values used were the averages of the two synoptic samples at each site. Parameters used. in the cluster analysis were TKN, T-P, TOC, Chlorophyll-a, turbidity and color. The highest degree of similarity occurred between the two detention basins, (Dl and D4), and the far downstream sites (1 and 17) also were clustered together at a high degree of similarity. Site 14 showed the least degree of similarity with any other site, (Figure VII-22). This finding is interesting in the light of the various observations of pollutant input above site 14 noted earlier in this report, and indicates unique conditions at that site compared to the rest of the watershed. 73

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"'-I 70 a,s3 E <-) o 1-49 .. Z 042 en n:: U U28 Z (.!) 21 n:: o -114 07 ---, -HOGTOWN POSSUM -.-.-TRIBUTARIES / ./ ./' ,.I' / /' /) /' I --. .I i ...... .' / /' --....... ". ...-""-.I // -...I o I! 1 I I I I I I I I! 1 17 2 5 044 01 6 12 19 (( 16 10 9 SAMPLE STATION NUMBERS GOING UPSTREAM ---,. --FigureVII-20 Toe vs. Distance UpstreamHigh Flow Sampling 4/3/80 Distance between stations not to scale.

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-...J In ,..------------------_.. 50 en E 45 .. () 40t .. 35 Z 0 CO 30 0::: () 25 () 20. Z (') 15 0:: 0 -1 10 tO 5 t-O HOGTOVVN --POSS.UM .-._.TRIBUTARIES ,..'-...... / -.. 17 2 50440161219 II 1610 14 9 SAMPLE STATION NUMBERS GOING UPSTREAM Figure VII-2l TOe vs. Distance UpstreamLow Flow Sampling 5/14/80 Distance between stations not to scale.

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Figure VII-22 Site Degree of Similarity -. ---", II DlJ LJ -J----t-J 12 I Cluster Analysis of 15 sites. Parameters TKN, CEL A, T-P, TURB, TOC, COLOR. Summary of Synoptic Studies Higher flow during the first synoptic (April 3, 1980), which followed a rain event, resulted in higher levels of parameters associated with particulate matter (TKN, turbidity) than during the low-flow event (May 6, 1980). Of the 15 sampling sites, station 14, below a suspected phenolic waste contributor, registered the poorest ,vater quality in terms of dissolved oxygen (D.G.), suspended solids, color, turbidity, biochemical oxygen demand (BODS) and total organic carbon. Poor water quality in terms of nutrient enrichment and high levels of BODs were evident at site 10, but decreased with distance downstream. This trend reflects the presence ofa treatment plant effluent above site 10. In general, the main branch of Hogto,vn Creek exhibited poorer water quality than did POSSlliu Creek. Somewhat different land uses in the two watersheds TIilly contribute to the differences in water quality. The watershed of Possum Creek is comprised mainly of suburban homesites, with some undeveloped wetlands and forest, and some unspoiled sections of creekbed" The main branch of Rogtown Creek runs through sections of commercialized land and is generally more intensely developed. In both tributaries, water quality becomes better with increasing distance downstream from the aforementioned sources. Water Quality in Rogtown Creek during a Storm Event A rainfall event was sampled during 22-23 January, 1980 at site 2. The sampling occurred before, during and after a 3.18 cm (1.25 in) rainfall, for the evaluation of both baseline data and influence of storm.water runoff on the receiving water quality. Measured parameters included flow, TKN, N03 + NOZ-' ortho-P, Ca, K, Na, Cl, conductivity, pH, turbidity, and dissolved lnorganic and organic carbon. Because samples were collected with an automated sampler, the effects of the 76

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runoff on some significant parameters such as dissolved oxygen and BOD could not be discerned. A storm hydro graph and concentration versus time plots for important water quality parameters are shown in Figures VII-23 to VII-27. Samples were collected hourly for a 28 hour time period by an automated Isco model 1600 sampler, and flow was determined ];yith an Isco Model 1700 flmy meter and recorder. Peak flow occurred 7-9 hr. after initial rainfall (Figure VII-23) and reflected two separate periods of intense rainfall. A ten day dry period preceding the rain event helped to establish baseline conditions in the stream. Parameters reflecting suspended solids, such as TKN and turbidity (Figure VII-24), increased in concentration as flow increased. This is t:o be expected,. because of the lower settling velocities of particulate matter in faster moving streams. Wash-off of loose debris also would contribute to an increase in suspended solids during a rain event. On the other hand, the concentrations of most dissolved species (N03 + NO,,-, ortho-P, dissolved carbon, Ca, Mg, Na, and Cl), as well as specific cc;nductivity, decreased as flow increased (Figures VII-25 and VII-27). This trend reflects the diluting effect of rainwater on dissolved species in the streamflow. In spite of the decreases in concentrations, loading rates (concentratioritimes flow) increased for all measured constituents during the period of storm runoff. First flush effects were noted for TKN, N03 + N02-, orthophosphate (SRP) and TOe, and the effect was particularly striking for TKN (Figure VII-23) .. Baseline concentrations of SRP were high, and throughout the event, levels of SRP were consistently greater than combined levels of the nitrogen forms. Nitrogen thus would be the limiting nutrient for plant growth under favorable conditions. The stormwater event data are in general agreement with data collected in other urban areas of Florida. Results for selected parameters (turbidity, TKN, NO; + NO;, SRP and conductivity) are compared to reportea a.ata .l.romtIiree other studles ln Table VII-4. The considerable ranges encountered for most parameters during runoff events complicates comparison of the several studies. In general, it appears that Hogtown Creek had low concentrations of inorganic nitrogen and high concentrations of SRP, compared to other sites in Florida. Sediment Studies Physical and Chemical Characteristics. Sediment analysis was conducted on ten samples in Hogtown Creek. Results (Table VII-5) showed the samples to be composed mainly of sand, except for that from site 6 (Figure VI-I), which was approximately 50% sand and 50% gravel. The organic content of the sediments was low for all ten sites, with maximum values of 7.2% (as volatile solids) at site 6 and 4.6% at site 19. The remaining sites contained less than 1.0% volatile solids. Total phosphorus levels in the sediments averaged 2.2 mg/g, with a high of 7.0 mg/g at site 6, and low of 0.15 mg/g at site 10. TKN values were low, reflecting the low organic content, and averaged 0.047 mg/g, with a maximum at site 5 (0.075 mg/g). Nitrate plus nitrite levels also were low at all ten sites, with a maximum value of 0.022 mg/g recorded 77

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I 1---------I vV; I I 4(d. .. -I I I 201-I 1--......... t RAIN I ) "-FLOW 10 I I --. CONDUCTIVITY i2am 6am JAN. 22 .. JAN. 23 I hours 12pm E 200 en o ..c: 150 E ::s > r-"> 100 to :J o Z o 50 U 6pm Figure VII-23 Storm Hydrograph and Conductivity Levels, Single Rain Event, January 22-23, 1980 78

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-...J \0 3.5 700 TKN A TURBIDITY k\ J 600 .. :> 3.0 ........ .. :t .. 506 .t: ; .. >Ol E 2.5 400 I_ .Cl .. Z 2.0 1.5 300 -f.D fl: 1.0 200 ::J 0.5 0.0 100 6pm I-JAN. 22 ,120m Som' 12pm 6pm '1. JAN. 23 -\ TIME, hours Figure VII-24TKN and Turbidity vs. Time, Single Storm Event t,_._---, NH4"-N o N03--N SRP .... () 0.6 Z (..) 0.5 (;) I_ 0.4' Z W 0.3 I-0.2 ::JI Z 0.1 0.0 6pm 120m 60m 12pm 6pm tJAN. 22 '1' JAN. 23 "I TIME, hours Figure VII-25 Soluble Nutrient Concentration vs. Time, Single Storm Event

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co 0 _I 45 C E 40 Co CI o No o Mg K 35l n::: 0 25," -) 20 2 l..L 15, -4 0 0 z 0 (.) o 12pm 6pm 120m 6clm 12pm 6pm 1--JAN. 22 -+ JAN.23 ---4 TIME, hours Figure VII-26 Concentrations of Major Ions vs. Time, Single Storm Event _..J -, t::n f." "6 ." 1(/) 32
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00 1-' Table VII-4 Characteristics of Stormwater from Florida Sites Constituent (mg/ L Unless Specified) Turbidity (mU) TKN N03+N02 -N NH+-N 4 SRP Conductivity 0 (1.1mho/ cm at 25 C) *NO--N only 3 Broward County 1 Residential Area Hean 12.S 3.0-7.0 ------0.535 0-3.6 0.343 0.01-2.6 0.21S 0.03-0.1S 9S.9 5.5-350 Orlando 2 Orlando 2 Commercial Residential Area Area 0.3-34 0.9-""24 0.07 .... 3.87 0.02-1. 96 0.11-. 33 0.03-:0.58 --''':"''--------------0.12-0.47 0.01-0.20 359-377 20S-251 Alachua County 3 Forested Area Hogtown Ck. Weight.ed :t-feans This Study 1975-6 1.976-7 Range ------_ .. -5.1-700 2.59 1.77 0.5:"'3.15 0.09 0.07-0.41 0.019-0.054 0.51 0.51 0.27-0.64 100-lS0 1Mattraw and Sherwood (1977). Study included samples from 30 runoff events in a 19 hectare single-family residential area in Pompano Beach, Fla. 2Wanielista, et al. (1977). Study included samples from two storm events in Orlando, Fla. 3Campbe11 (1979). Data shown are weighted mean concentrations for stormf1ow events throughout the year in a 437 hectare watershed composed of forest. (63%), unimproved pasture (8%).and cropland (29%).

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Table VII-S Sediment Analysis Results % Volatile % % % mg/g mg/g mg/g mg/g J..Ig/g Sample Solids Gravel Sand Clay Total-P (P) TKN (1'1) 'N03';'NOZ (N) Pb Fe .... --....:.. ... -1 0.4 0.4 96.2 3.4 5.32 .055 .002 0.04 0.71 2 0.0 0.3 98.8 0.9 2.63 .041 .003 0.05 0.47 4 0.5 0.7 97.7 1.6 2.33 .053 .011 0.08 0.37 5 0.3 0.1 99.3 0.6 .075 .022 0.05 0.38 6 7.0 45.8 53.6 0.6 7.03 .028 .007 0.05 2.67 9 0.3 4.2 93.5 2.3 0.40 .033 .002 0.03 0.51 00 N 10 0.6 2.2 96.4 1.4 0.15 .048 .007 0.10 0.90 19 4.6 1.3 98.4 0.3 1.31 .036 .012 0.03 0.41 21 0.7 0.9 98.2 0.9 0.16 .048 .005 0.02 0.46 22 0.3 1.0 98.0 1.0 0.50 ;014 0.03 0.66

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at site 5. Although site 10 was directly of the discharge point for a wastewater effluent, it had the lowest total phosphorus level of all samples and an average nitrogen level, thus indicating that the effluent has no significant impact on the stream sediments. The sediments contained trace quantities of lead (Pb) with a maximum value of 0.10 mg/g at site 10. Total iron concentrations ranged from a low of 0.41 at site 19 to a high of 2.67 pg/g at site 6. Site 6 is located upstream of an intersection with a roadway. Sites 22 and 19 are above and helmv a Mall, respectively but no impact of this land use can be seen in the lead results. In summary, the chemical analyses performed on sediments from Hogtown Creek indicate that organic matter and lead levels low, and the sediments consist primarily of uncontaminated sand. Benthic Invertebrates. Benthic invetebrates are useful as indicators of water quality conditions and environmental stress. Because of their relatively sedentary nature and extended life cycles, they are not able to escape periodic episodes of pollution, and thus they reflect the integrated conditions of w'ater quality over a relatively long period of time. Benthic invertebrates are important to the ecology of streams and aid in the breakdown of detrital material. Many invertebrate groups such asamphipods and oligochaetes are also important sources of food for certain fish species. A knowledge of the environmental requirements of specific species of benthic invertebrates found in an area can be useful in assessing water quality conditions. The biological sampling routine used here was designed to obtain an overview of thehenthic invertebrate cornmunitiesin the Hogtown Creek and was by no means an exhaustive characterization of the entire benthic system. Variations in both time and space can be expected in the benthic communities of any flowing body of water. Benthic data presented in this report should be viewed as a preliminary guideline in the relative condition of various portions of the creek. The number of benthic invertebrate species collected from Hogtown Creek ranged from a low 6f two at station 20 to a high of 21 at station 9 (Table2VII-6). The number of individuals zollected ranged from a low of 569/m at station 11 to a high of 77205/m at station 14. Both stations D-4and D-l were dry at the time of sampling and will not be considered in the following discussion. A composite species list of benthic invertebrates collected from the 14 non-dry stations along the Hogtown Creek is presented in Table VII-7.. Stations 2 and 5 were similar in both number of species and diversity as measured by the Shannon-Weaver diversity index (H') (Table VII-7). Both stations were dominated by midge larvae and also contained lesser numbers of Oligochaetes, Pelecypods and Ephemeroptera. Overall, stations 2 and 5 appeared to be two of the most diverse stations sampled. Station 4 contained fewer species than stations 2 or 5 and was also dominated by midge larvae with being the single most common species. 83

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Table VII-6 Number of benthic invertebrate species and Shannon-Weaver site diversity. H'. Station No. Species No. Individuals (1m2 ) H' *;"Biomass 2 (g/m ) 2 18 10500 2.6 13.88 5 21 20999 2.5 0.73 4 14 9458 2.3 0.38 D4* D5* 1 16 1453 2.7 2.24 17 11 2089 2.0 7.96 9 20 14088 2.5 0.32 10 17 4545 2.2 0'.30 11 10 567 2.2 0.05 12 12 2452 1.7 19.28 6 16 11045 1.5 1.98 19 11 17772 0.8 0.74 16 15 4294 2.3 0.34 14 T 61864 0.2 8.67 20 2 16410 0.1 3.55 Station dry at ti.TIie of sampling. ** Values are for ash-free dry weight after combustion at 550C. 84

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Table VII-7 Composite benthic invertebrate species list. Each number represents the number of benthic organisms per square meter. Station Number 1 2 4 ___ ____ __ 2 ____ ._l0 .. l!f .. ___ 16 17 19 2f1 Turbel1aria Dugesia sp. 91 1091 23 45 /-.:;; Nemertia Unidentified %1 1+5 91 68 t+5 23 4'-.J 114 114 Nematoda Unidentified 45 23 91 205 45 114 01igochaeta Limnodri1us hoffmeisteri 91 1750 13!fl 796 91 205 -----------_ 91 45 23 76273 273 7069 16182 Lumbricu1us sp. 23 Branchiura sO'werbyi. 637 228 Gastropoda Lanx sp. 91 Gyrau1us a1tissimus 91 !+5 137 455 Physa sp. ,23 23 Sphaerium sp. 91 co Pe1ecypoda In Corbicu1a f1uminea l37 1.+5 ----137 23 954 705 Amphipoda Hya1e11a azteca 68 Isopoda Ase11us sp. 205 23 Coleoptera Ancyronyx variegata 68 Cy110pus sp. 45 Ha1ip1us sp. Stene1mis sp. 68 45 Tricoptera Cyrne11us sp. 23 Cheumatopsyche sp. 91 227 205 23 591 23 Ephemeroptera Baetis sp. 23 137 45 68 23 Ephemere11a sp. 114 Stenonema sp. 114 159 Ame1etus sp. 45 523 45

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Table VII-7 continued Station Number 1 2 4 5 6 --L_..JJL. __ 11 __ 12 lA __ ___ 17 _____ l9 20 Odonata Enallagma sp. 45 Progomphus sp. 68 23 111+ Didymops sp. 45 Gomphus sp. 23 Agrion sp. 23 Nehallenia sp. 91 Collembola Isotamurus palustris 45 23 Diptera Bezzia sp. 23 23 23 Brachydeutera sp. l14 205 45 Stratiomyidae 23 Nemotelus sp. 23 Hemerodomia rogatoris. 273 Tipula sp. 137 23 00 Chironomus carus 0\ Tanytarsus sp. 68 364 477 13978 7591 2546 136 23 1864 23 Cricotopus sp. 45 11750 318 1364 23 23 Cryptochironomus fulvus 319 23 23 227 146 23 91 Ablabesmyia parajanta 205 Lj 205 1546 409 341 91 Paralauterborniel1a sp. 387 23 23 Po1ypedilum sp. 7387 568 2682 9523 2387 159 114 273 91 6887 1409 Po1ypedilum halterale 45 4864 45 23 137 Trichocladius sp. 91 45 23 23 45. 23 68 23 Rheotanytarsus sp. 318 45 91 614 23 23 23 Chironomus attenuatus 137 91 23 68 91 182 Thienemanniella sp. 250 23 23 Paracladopelma sp. 569 341 273 45 23 136 modestus 432 91 45 Coelotanypus sp. 45 sp. 23 23 Xenochironomus sp. 728 Tanypus carinatus 1114 68 Procladius sp. 68 68 45 336 Tribelos 387 23 68 23 Chironomid Pupa 23 4341 273 1955 1955 886 159 45 23 432 Unidentified larvae 23 91

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Station 1 was located next to Haile Sink at the southern most extent of the Creek. The benthic community at this station was fairly diverse with 16 species and a Shannon-Weaver diversity of 2.7. The total number of individuals at this station was fairly low with 1477 organisms per meter square. Representatives of the Turbelloria, Nemertia, Nematoda, Oligochaeta, Molluska, Amphipoda, Ticoptera, Ephemeroptera, Odonata and Diptera were all present at station 1. No single species was found to be very dominating at this station. Station 17 contained 11 species and 2094 organisms/m2 This station appeared to be less diverse in species richness and was dominated by the Oligochaetes Limnodrilas hoffmeisteri, Branchiura Sowerbyi and the pelecypod_Corbicula fluminea. Stations 9 and 10 were similar, with 21 and 17 species respectively. Stati2n 9 had a considerably greater number 2f individuals (14184 organisms per m as compared with 4647 organisms per m ) while both stations had similar values for H'. Both stations 9 and 10 were dominated by the midge larvae Polypedilum. E.. Stations 11 and 12 had similar numbers of species, 10 and 13 species respectively, but station 11 had less than one fourth of the total number of individuals. Station 11 had the smallest number of individuals of any station in the present study, and it was dominated by both the ephemeropteran Baetis 32;. and the midge PolypedilUIil Station 6 contained 16 species and 11049 individuals/m2 The Shannon-Wea'ler diversity was fairly low (1.5) due to the heavy dominance by the dipteran and Ablabesmyia paraJanta. Station 19 contained 10 species and was heavily dominated2by yolypedilum which contributed 9523 out of a total of 17815 organisms/m. Due to the heavy dominance of a few species, HI for station 19 was low (0.8). Station 16 contained 15 species and 4377 organisms/m2 This station was dominated by Diptera larvae and had an HI value of 2.3. Stations 14 and 21 were the least diverse areas studied with 7 and 2 species respectively. Both stations had very low values for H' (0.2 and 0.1 respectively) and were heavily dominated by the oligochaete Limnodrilus hoffmeisteri. Information on the environmental condition of a stream can be obtained by looking at the distribution of various indicator species .. A number of species such as Limnodrilus hoffmeisteri and Chironomus attenuatus are known to tolerate low oxygen conditions and are often found in large numbers in polluted areas. In a study by Mason et ala (1972) an attempt was made to group benthic invertebrates into pollution tolerant and intolerant categories. This grouping was based on the ability of the species to tolerate low oxygen conditions brought about by organic pollution. In the case of the Hogtown Creek, conditions other than low oxygen concentrations also are of concern relative to the distribution of benthic species. Therefore, simply considering the presence of indicator species based on oxygen stress, may be misleading. 86

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Although a more extensive sampling program is needed to completely characterize the benthic invertebrates of Rogtown Creek, a gradient of decreasing diversity (both species richness and equitability) can be detected from the present data. Stations 2, 5, 1, 9, 10 and 16 appear to be more diverse and thus in a better state of "health" than stations 19, 14 and 21. 88

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VIII. SUMMARY AND CONCLUSIONS SIGNIFICANCE OF URBAN DEVELOPMENT The City of Gainesville has experienced a rapid and sizeable growth over the past few decades and has developed into a major metropolitan area in north-central Florida. As in any expanding urban area, growth of this type brings about changes in land use and a clearly visible alteration in the hydrology of the region. In the case of Gainesville these changes have a special significance since there are no surface outflows from the area. The sink hole systems of the region have a limited capacity for accepting runoff, beyond which backwater and flooding result. 'i'hisfact has been illustrated with increasing frequency in recent years as runoff rates and volumes have increased with residential and commercial development. Concomitant with hydraulic constraints are the natural limitations of the stream systems to accept waste discharges and polluted runoff. The last major flooding in the basin occurred in October 1970 when a tropical storm passed over the. City. This sparked local interest to the extent that a city flood control ordinance was passed in 1973 prohibiting development in the 10-year flood channel and restricting it in the lOO-year flood plain. Requirements for detention to contain the 4-year storm volume followed. That serious flooding has not reoccurred since 1968 may speak partially to these ordinances but is more likely attributable to the absence of large storms since that time. However, with the large nUlnber of detention/retention basins now constructed in the City, the flooding potentiaL has probably not been greatly worsened since the early 19701s. But heavy rains could again cause innundation in low areas, particularly in the area southwest of West University AVe. and SW 34 St: Gainesville enjoys a rather mild climate with temperatures averaging 70F over the year and rainfall near 54 inches. Much of the rainfall comes during late SUTIl.l11er and has a considerable effect on flows in the Hogtown Creek system. Host of the Hogtown Basin is residential in land use, with commercial areas along University Avenue and on NW 13 St. Continued growth in both sectors is expected over the next few decades, expanding to the boundary of the basin, approximately 23 square miles in area. The geology of the area is karst in nature with scattered sink holes. Local groundwater serves as the base level for the flatlands and prairies. Soils in the area range from very poorly drained to well drained, with the ecology being predominately hardwood flood plains, wetlands and marshes. The City and public are aware of many aspects of the changing ... hydrologic and quality characteristics of Hogtown Creek. Newspaper articles and ordinances followed the flooding of the early 70's. Recently the quality of water in the creek has been in the limelight due to City Commission action on a construction setback line and several newspaper articles about the c9ndition of the creek (e.g., most recently in the March 24, 1981 edition of the Gainesville Sun). Based upon observations made during this study and by many others, storm water runoff obviously contributes most of the visible pollutants to the creek. (The chemical 89

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and biological parameters are discussed below.) This will increase with increased urbanization. And other problems, such as the phenolic leachate, are wet-weather related. Current flood management efforts include stormwater detention/retention basins, installed for quantity control. These also act as sedimentation basins and provide a measure of quality control. This effect has not been demonstrated in this study due to a lack of sufficient rainfall during the sampling period. (However, extensive sampling is being conducted elsewhere under several current EPA National Urban Runoff Program projects.) Efforts are underway to maintain open space and floodplain buffer areas for both quantity and quality control. The retarding effect of the flood plain vegetation reduces the downstream impact of floods. The vegetation itself filters out floatables and sediment. Its effect on chemical and biological parameters-depends upon the detention time of the water in the flood plain and is difficult to quantify. For detention times of only a few days, probably few soluble nutrients, for example, would be removed. However,most particulate matter would be. Acquisition of flood plain lands by the City would ensure their managed use fur recreation and water quantity and quality control. It should be borne in mind that although a flood plain buffer is good, it\olillnot act upon the source of contaminants to the creek. Other non-point source controls such as street cleaning, detention/retention basins, erosion control, etc. will be necessary to reduce existing sources of pollution from highways, commercial areas and developments. Improved public awareness has the potential to reduce contamination from home fertilizer, pesticide and herbicide applications. However, this study did not document a cause and effect relationship between stream water quality and household activities. DATA BASE The hydrology of the Hogtown Basin has been studied by a number of concerns but usually with flood control and property protection as the impetus. Studies of the effects of pollution on the stream system have been confined mainly to the upper reaches of Hogtown Creek and were directed specifically at the Cabot Carbon phenolic wastes. Probably the most comprehensive overview of water quality and aquatic biota was presented as part of the 201 Plan, but dealt mainly with the region surrounding Haile Sink. A more complete study of the stream system as a whole has been This study monitored several water quality parameters, as discussed However, it. did not explicitly deal with all parameters listed under Chapter 17-3, "Pollution of Waters" in Rules of the Department of Environmental Regulation. Moreover, instrumentation was not available at the time of the sampling program to identify phenols, pesticides and herbicides. (The Dept. of Environmental Engineering Sciences at the University of Florida now contains a GC-Mass Spectrometer for purpose.) Hence, further studies would be needed for a more thorough assessment. 90

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Finally, flow monitoring was difficult at most stream locations because of its shallow nature. Even at the weir at NW 34 St. measurement was inaccurate because of the very shallow depths (a few inches) of flows 'over the weir crest. In future studies, greater accuracy could be achieved only with extra funding for installation of temporary flmv constrictions such as Parshall flumes or V-notch weirs. This is also true at detention ponds where only a sizeable storm raises inflow and outflmv levels to depths at ""hich they can be monitored. \vATER QUA-LITY HONITORING Several ,-:rater quality parameters were measured in four manners: 1. Three stations (Possum Creek and the Main Branch at NW 16 Hogto'!fm Creek at NH 34 St.) and two detention ponds were monitored weekly for 15 weeks, from February 4 to May 14, 1980. 2. Fifteen stations were---monitored twice during the study, once during a relatively wet period, April 3, 1980, and once follm"ing a relatively dry period, May 14, 1980. These were the synoptic surveys. 3, A storm event on January 6, 1980 was sampled intermittently for 28 hours at }TI{ 34 St. 4. One sediment and benthic survey was performed. Sampling sites are shown in Figure IV-l and the results discussed in detail in Cllapter VII .. From the weekly monitoring, the total flow at NW 34 St. was greater than the sum of the two tributaries along 16 Ave. Generally dry weather prevailed during this time period, and the flood plain area upstream from NH 34 st. apparently contributed additional base flmv. Additional flow'S could also have originated from unmonitored tributaries such as Rattlesnake Branch. During storm events the upstream flood plain attenuates flmvs. From the weekly monitoring, some parameters were found at fairly low levels and typical of natural waters, but others were not. For instance, turbidity and color were higher than nearby natural Although BOD was 10lver than "typical" storm\vater, it was nonetheless at levels characteristic of other urban rivers where stormwater may be a problem. Nitrogen levels were comparable to urban stormwater and higher in some forms than found in most natural streams. TKN exhibited a "first flush" phenomenon during storms, indicating that it built up during dry weather. Phosphorus levels ,,,ere quite high, and comparable to Florida rivers draining phosphate laden soil. Oddly, hmvever, it does not seem to have increased dramatically in 28 years. The creek is probably nitrogen limited due to these high phosphorus levels. 91

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Very high total and fecal coliform levels were observed, typically 60 percent greater than DER standards for class III (recreational) waters. Ratios of fecal coliform to fecal strep were frequently greater than 4.0, indicating likely human origin. What is the source of such Inaterial on the main branch of Hogtown Creek? Quite possibly there is residual septic tank drainage from homes near the stream that have never been connected to the sewer system. Of course, high coliform counts are indications of potential health hazards, and swinnning would not be permitted by a health department with the levels found in Hogtown Creek. Although limited by low rainfall and little water to sample, detention ponds generally mirrored Hogtown Creek in their water quality. Of interest are the lower nutrient concentrations found in the pond with more machrophytes (e.g., large plants). During the synoptic surveys it was clear that site 14 at NW 6 St., downstream from the phenolic leachate, had the worst water quality in almost every way. Color, turbidity and fecal coliforms were particularly high. This simply adds confirmation to what is already known visually and from otller stu.dies Otherwise, parameter concentrations were generally typical of those measured during the weekly survey. Nutrient concentrations were high on Possum Creek at NH 39 Ave., as would be expected downstream from a sewage treatment plant, but concentrations diminished downstream. This location also had a slightly higher BOD. Several parameter concentrations were higher during the llwet" survey (April 3) than during the dry survey, especially even more of the impact of stormwater on the creek. The mass load of all constituents was higher during higher flov], as evidenced by the synoptic and the storm event monitoring. The main branch of Rogtow'Il Creek generally exhibited lower water quality than did Possum Creek. This may be attributed to the much more intensive land use and development on the main branch) flowing as it does through the heart of Gainesville. This may possibly bode ill for Possum Creek as urbanization continues. Sediment samples indicated no significant degredation of the stream bed. The present bed consists mostly of sand, and lead levels were low even near the Gainesville NaIl. However, the benthic invertebrates indicated very poor conditions at the upstream end of the main branch, again confirming the poor water quality of that region. Overall, the "Tater quality of Hogtown Creek as sampled in this study ,vas characteristic of urban runoff, not natural waters. This negative connotation leaves little doubt that stormwater contributes significantly to the degradation of the creek, visually, chemically and biologically. Perhaps of the most concern are the very high coliform levels; public health hazards could well exist, for instance, if children play in the creek. 92

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DETENTION Pm-IDS Owing to sampling during a predominately dry period, too few data were collected to assess detention pond performance on water quality. Physical data for several ponds are presented in Appendix B and could be used in future mathematical modeling studies in conjunction with a sampling program for model verification. Although it is unfortunate that this study.cannot address their effectiveness for water quality management, it is likely to be significant for removal of sediment and particulates from runoff upstream of areas where they have been installed. Removal of soluble nutrients will depend upon detention time of water within the basin and cannot be conjectured. Their effectiveness for flood control may readily be demonstrated conceptually. Whether the many detention/retention basins installed since the early 1970's will reduce potential flooding in the downstream reaches of the Hogtown Basin awaits the trial of a major storm. 93

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REFERENCES 1. Alachua County Pollution Control District, Memorandum, "Historical Summary of Cabot Carbon Waste Problem," Gainesville, FL, June 5, 1980. 2. Alachua County Pollution Control District, Memorandum, "Cabot Carbon \vaste Leachate. Into HogtoW'n Creek," Gainesville, FL, Undated. 3.' Alachua County Pollution Control District, Memorandum, "Cabot Carbon-Hogtown Creek \vater Quality Results," Gainesville, FL, Undated. 4. Brady, N.C., The Nature and Properties of Soils, 8th Ed., MacMillan Publishing Co., lnc., 1974. 5. Brown, M. et aI., Vegetation and Land Use of the St. John's River Water Management District, Center for Wetlands, University of Florida, Gainesville. FL, 1977. 6. Burdne':r, R. and J. Winter, eds., Nicrobial Nethods for Nonitoring the 1978. 7. Burton, T.M., R.R. Turner and R.C. Harris, "The Effects of Land Use on Non-point Source Pollution in Florida," Journal Water Pollution Control Federation, Vol. 51, No.6, 1979. 8. Christensen, B.A., C. Vargus, S.D. Herrera and J.J. Victoria, Identification arid Evaluation of Natural Detention Sites in Hogtown Creek Drainage Basin, EIES special report, University of Florida, Gainesville, FL, 1974. 9. CH2M-Hill Southeast Inc., Alachua County 201 Wastewater Facility PlaQ for the City of Gainesville, Florida,. Gainesville, FL, 1978. 10. Department of Environmental. Regulation, State of Florida, Pollution of Waters, Chapter 17-3.09, Criteria: Class III waters, Undated. 11. Department Nemorandum: 7, 1977. of Regulation, State of Florida, Interoffice "Survey of Hogtown Creek," Tallahassee, FL, December 12. Doyle, J.R., Evaluation of Land Use Alternatives to Control Urban StorIWwater Quality, M.E. Thesis, University of Florida, Gainesville, FL, 1973. 13. Edmondsan, W.T., ed., Fresh-Water Biology, John Wiley and Sons, Inc., New York, 1959. 14. Gainesville, City of, Department of Community Development, Environmentally Sensitive Areas, Gainesville, FL, 1975. 15. Great Lakes Region Commission on Analytical Nethods, Chemistry Laboratory Nanual: Bottom Sediments, EPA, Federal Water Quality Administration, 1969. 94

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16. Green, H.H., Interim Report on a Drainage Study of Stormwater Runoff Produced by Northwood Subdivisions, Gainesville, FL, 1973. 17. Huber, W.C., J.P. Heaney and S.J. Nix, Storm Water Management Model User's Manual-Version III. EPA report, Cincinnati, Ohio, 1980. (Draft). 18. Hynes, H.B.N., The Ecology of Running Waters, University of Toronto Press, 1972. 19. King. and E.F. Brater, Handbook of Hydraulics, McGraw-Hill, Inc., 1963. 20. Krueger, R.C., Evaluation of a Proposed Natural Retention Basin System Within the Hogtown Creek Drainage Basin, M.E. Thesis, University of Florida, Gainesville, FL, 1972. 21. Marcus, S.R., Rejuvenation of Hogtown Creek, M.S. Thesis, University of Florida, Gainesville, FL, 1971. 22. Mason, W.T.,J.B. Anderson, R.D. Kreis and W.C. Johnson, "Artificial substrate sampling, macroinvertebrates in a polluted reach of the Klamath River, Oregon." Jour. Water Poll. Control Fed., Vol. 48, R3l5-328, 1972. 23. Mattraw, H.C., Jr. and C.B. Shenvood, "Quality of Storm Water Runoff from a Residential Area, Broward County, Florida," Journal Res. USGS, VoL 5, No.6, .1977, pp. 823-834. 24. NOAA, Climatological Data, National Climatic Center, AsheVille, NC, Published monthly. 25. North Central Floridal Regional Planning Council, Metropolitan Transportation Planning Organization, Socioeconomic Growth Analysis, Gainesville, FL, 1979. 26. North Central Florida Regional Planning Council, Open Space and Recreation, Gainesville, FL,' 1973. 27. o dum H.T. IlDissolved Phosphorus in Florida Waters," Florida Florida Geological Survey, 1952. 28. Pennak, R.W., Fresh-Water Invertebrates of the United States, The Ronald Press Company, New York, 1953. 29. Powers, C.F. and A. Robertson, Design and Evaluation of an All-Purpose Benthos Sampler, Great Lakes Research Division, University of Michigan, Special Report 30:126-133, 1967. 30. Snedaker, S.C. and A.E. Lugo, Ecology of the Ocala National Forest, U.S. Department of Agriculture, Forest Service, 1972. 31. Standard Methods for the Examination of Water and Wastewater, 14th Ed., APHA-AWWA-\\1PCF, 1975. 95

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32. Sundaresan, B. B. et a1., lIEffects of Wood Reduction Ivaste Pollution on the Microbial Ecology of a Small Creek,lI Journal Pollution Control Federation, Vol. 37, No. 11, 1965. 33. Sverdrup & Parcel and Associates, Inc., A Report on a Flood Plain and Water Control Program for the Headwaters of Little Hatchet, Turkey, Blues and Hogtown Creeks, for the North Central Florida Regional Plan ning Council, Gainesville, FL, 1973. 34. S'TerdD.lp & Parcel and Associates, Inc., Water and Flood Plain Hanage.ment Study for the Gainesville Hetropolitan Area, 1974 Drainage, for the North Central Florida Regional Planning Council, Gainesville, FL, 1974. 35. U.S. Department of Agriculture Soil Conservation Service, Special Soil Survey Report, 11aps and Interpretations) Alachua County, Florida, Fort Worth,TX, Undated. 36. D.S. Environmental Protection Agency, Region IV, Surveillance and Analysis Division, "Hazardous Waste Site Investigation, Old Cabot Carbon Site, Gainesville, Florida," December 1979. 37. U.S. Geological Survey, Water Resources Data For Florida, Volume I, Tallahassee, FL, Published Yearly. 38. U.S. Geological Survey; Springs of Florida, Special Bulletin No. 31, Tallahassee, FL., 1977. 39. Vargus, C., Evaluation of Area Parameters Controlling Stonm.;rater Runoff in HogtovTIl Drainage Basin, H.E. Thesis, University of Florida, Gainesville, .t'L. 1972. 40. Victoria, J.J., The Hogto1;vu Creek System With Detention Basins Included, M.E. Thesis, University of Florida, Gainesville, FL, 1974. 41. Wanielista, H.P. > Y.A. Yousef and H.H. McClellan, "Non-Point Source Effects on Water Quality," Journal Hater Pollution Control Federation, Vol. 49, No.3, 1977. 42. Water Resources Data for Florida Vol. 4, N.W. Florida, USGS FL-79-4 pp. 177-203, 1979. 43. Weibel, S.R., R.J. Anderson and R.L. Woodward, "Urban Land Runoff as a Factor in Stream Pollution," Journal Water Pollution Control Federation, Vol. 3&, No.7, 1964. 44 .. Wharton, C.H. et aI., Forested Wetlands of Florida-Their Hanagment and Use, Center for Wetlands, University of Florida, Gainesville, FL, 1977. 96

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Appendix A. Photographs of Detention Basins and Creek Sample Sites Photo A-I. View ,of Basin DI looking southward. Basin is surrounded by cyclone fence. Inflow is from catch basins along street gutter; outflow is located on opposite side of basin. Photo A-2. View of Basin D3 looking northward. Basin is surrounded by grassy berm. Inflow is from left near person standing in center of basin; outflow is to right. Photo A-3. View of Basin D4 looking southward. Basin is in-stream with inflow at bottom of photo. The outflow structure to the upper left of photo consists of an orifice with a concrete overflow. Photo A-4. View of Basin D5looking west'tvard. Basin is surrounded by cyclone fence. Inflow is from catch basin along street gutter; outflow is at bottom of photo discharging to a ditch. Note emergent growth. PhotoA-5. View of Basin D7 looking westward. Basin is surrounded by cyclone fence. InflQl;vis from catch basin along street, the point from 't"hich photo was taken. Overflow structure is in the center of the basin and drains Photo A-6. Photo A-7. Photo A-S. Photo A-9. to the street to the north, eventually reaching the creek to the west. View of Possum Creek looking southward, in the vicinity of sample site 5. Tee overpass shown is that of N.W. 16 Avenue. View of Hogtown Creek looking eastward, in the vicinity of sample site 2. Note weir structure and concrete blocks traversing the creek. View of Hogtovm Creek looking westward. taken from concrete block of photo A-7. is N.W. 34 Street. Photo was The bridge View of Hogtown Creek looking northward, in the vicinity of sample site 4. The overpass shown is that of N.W. 16 Avenue. 97

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Photo A-I. Basin D-I Photo A-2. Basin D-3 98

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Photo A-3. Basin D-4 Photo A-4. Basin D-5 99

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Photo A-5. Basin D-7 Photo A-6. Sample Site 5 100

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Photo A-7. Sample Site 2 Photo A-S. Sample Site 2 101

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Photo A-9. Sample Site 4 102

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Appendix B. Physical Characteristics of Selected Detention Basins. Figures B-1 through B-S depict Stage-Discharge and Stage-Surface Area relationships for basinsDl, D3, D4, DS and D7, respectively. Approximate dimensions of the basins are sho,vn along with an indication of side slope and outlet structure. Table B-1 through B-S contain the data that were generated for use in the.graphs. Physical dimensions of the basins and side slopes were obtained from subdivision master plans and by site inspection. Table values were developed following an assumed geometry. 103

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Table B-1 Basin D1 Stage-Discharge-Surface Area Volume (ft3) ; Discharge(cfs) Surface Area(ft2 ) 0 0 0 20000 1.0 20679 0 22464 1.5 32983 1.1144 23744 2.0 45936 1.5758 25056 2.5 59394 1.9298 26400 -3.0 '73268 2.2283 27776 3.5 87499 2.4913 29184 4.0 l02042 2.7292 30624 .5 116863 2.9478 .0 131937 33600' 6.0 162157. 3.5228 ',6704 Table B-2 Basin D3 Stage-Discharge-Sur'face Area Depth(ft) .. q Vo1ume(ft-) Discharge (cfs) 2 Surface Area(ft ) 0 0 0 46250 1.0 0 49256 1..5 73012 6.9635 50786 2.0 99711 9.8479 52334 2.5 126978 12.0612 53900 3.0 154706 13.9271 55484 3.5. 182824 15;5710 57086 4;0 211280 17.0572 58706 4.5 240035 18.4238 60344 5.0 269058 19.6959 62000 6.0 327812 22 .. 0207 65366 6.5 366662 23 .. 0955 67076 104

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Table B-3. Basin D4 Stage-Dis charge-Surface Area c Depth(ft) 3 Volume(ft ) Discharge(cfs) 2 Surface Area(ft ). 0 0 0 15200 O.S 7345.7 0 15926 1.0 15927 6.96357 16488 1.5 24407 9.848 17056 2.0 32984 12.0613 17620 2.5 4263.3 13.9271 18210 3.0 51196 15.571 18796 3.5 61560 17 .057 19389 4.0 70585 18.4239 19987 4.5 80998 19.696 20591 5.;0 91177 20.8907 21201 6.0 112995 23.0955 22439 Table B-4. Basin D5 Stage-Dis charge-Surface Area Depth(ft) Volume(t 3 ) Discharge (cfs) 2 Surface Area(ft ) 0 0 0 2750 .5 1455 0 3074 LO 3077 0 3416 1.5 4874 10.03 '3776 2.0 6856 14.18 4154 2.5 9031 17'.37 4550 3 .. 0 11409 20.06 4964 3.5 13998 22.42 5396 4.0. 16808 24.56 5846 105

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Table B-5. Basin D7 Stage-Discharge-Surface Area Depth (ft) 3 Volume(ft ) Discharge (cfs) 2 Surface Area(ft) 0 0 0 5046 1 5483.16 9.84797 6270 1.5 9092.6 12.061 6930 2.0 13018 13.9271 7622 2.5 17196 15.571 8346 2.75 19367 16.331 3.0 21587 17.0572 9102 3.5 26164 18.424 9890 L}.O 30906 19.6959 10710 r 4.,:) 35798 20.891 11562 5.0 40826 22.0207 12446 5.5 45980 23.096 13362 106

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J I 16 BASIN I S"OUTLET" ABOVE BOTTOM ,F=2OOI=i t ..1110' / / if II SIDESLOPE 4 I /1 2 DEPTH, feet Figure Volume and Discharge vs. Depth in the Detention Basin 107

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-W rn '-" 0:: () en o I BASIN 3 DRA!NS 27.2 ACRES I -241 df'\ l .v r 15!! OUTLET j' ABOVE BOTTON I I 35 /{.;o' II SIDESLOPE 3 [8 30 L J7 J / I / L I !I m// .:::: 25 DISCHARGE. ,I 10 1-! 121 W "0 L 1-', I I /VOLUME 19 !ii /1 1,;:::> L" i5 I I I l! [/ / iO / i I I / 5 J I 1/ i j o 0 DEPTH, feet Figure B-2. Volume and Discharge vs. Depth in the Detention Basin 108

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6 BASIN 4 DRAINS 26.1 ACRES 16 rl_Z5'" OUTLET 0.5 ABOVE BOTTOM I 1 I SIDESLOPE 14 2 6 7 DEPTH, feet Figure B-3. Volume and Discharge vs. Depth in the Detention Basin 109

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i6 BASIN 5 I DRA1NS -4 ACRES 14 L 6" Ol.,.'TLET !" ABOVE BOTTOM i i i SiDESLOPE I :3 I / 121 I 15{ / iO 8 !-.. / !VOLUME I I / iii / / I / 6 r,l, lj 4 i-/1 I / I i / I 2 / J II 1/ o o feet Figure B-4. Volume and Discharge vs. Depth in the Detention Basin 110

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45 BASIN 7 40 l-15" CUTLET ON BOTTOM II DRAIN 8.3 ACRES II SI':SlDPE n' I .,' r 0 r a::: 15 I / 61 10 / o 2 3 4 5 6 7 DEPTH, feet Figure B-S. Volume and Discharge vs. Depth in the Detention Basin III

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Appendix C. Rainfall Recorded at Gainesville, Florida February-July 1980 Table C-lcontains data recorded at four gages in the Gainesville area. Stations #1 and #2 were continuous-recording weighing-bucket gages maintained by project personnel. Values are given for the 24-hour period of the date indicated. Station #3 is maintained at the Gainesville Airport where accumulated rainfall is recorded every six hours. Values are given for the 24-hour period of the date indicated. Station #4 is maintained by the University of Florida Agronomy Department Accumulated rainfall is recorded at 5 PM daily. Values are given for the preceding 24-hour period. 112

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Table C-1. Rainfall Recorded at Gainesville Area Gages (inches) Station 1 2 3 4 Date 2-10 .18 .12 13 .02 0 14 .01 .02 16 .47 .46 17 .13 .13 24 .94 1.13 25 0 .02 3-1 .20 .15 2 .11 .10 3 0 .02 9 1.05 .84 10 .75 .61 13 .20 .22 21 .18 .04 25 .01 0 28 .06 .01 29 .10 .11 30 .87 4-2 1.96 1.68 3 .. 65 .91 4 .61 .19 5 0 .36 7 0 .04 9 .06 .09 10 0 .02 14 .73 .62 19 .40 .40 .41 .25 20 0 0 0 .02 5-3 0 0 .04 0 4 1.98 1.35 .69 .02 5 0 0 .18 .30 8 .98 .95 .82 .90 9 .90 .85 .98 1.09 15 .65 .60 .18 0 16 .25 .82 .48 17 0 .10 .40 18 0 0 .02 21 0 0 .16 22 .55 .88 .59 23 .61 .53 25 .79 .56 26 0 .03 113

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Table C-1. Rainfall Recorded at Gainesville Area Gages (inches) (cont'd) Station 1 2 3 4 Date 6-8 .40 0 0 0 10 0 .15 .19 .21 13 .55 0 0 0 18 0 .45 0 .06 19 .20 .17 .13 20 .22 .03 21 .55 .63 .03 22 .15 .21 .44 23 .30 .23 .02 24 .30 .25 .09 .15 25 .13 .10 .33 .16 26 .65 .85 .59 27 0 0 0 .01 28 0 0 0 .12 29 .07 .15 .15 30 111 ._v .07 .19 7-2 0 0 0.2 .0 3 -." .10 0 6 .05 .08 .13 7 .20 .65 .12 12 3" v .20 .20 1 I. .'+u .40 .42 17 I.J 0 0 18 .17 .15 .79 19 0 0 .01 20 0 0 .07 22 .13 23 .51 24 2.05 2.15 .92 25 2.40 1. 85 1.53 26 0.65 0.65 27 .55 .40 29 .86 .50 Blank spaces indicate vlhere data were not recorded. 114

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Appendix D. Descriptions of Vegetative Communities Appendix D provides descriptions of some of the classifications illustrated in Figure VI-2. Map code numbers correspond to the unit numbers of Table VI-2. 115

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Appendix D 1. Grassy Scrub. Map code 20; State code 311. Also known as dry prairie and native rangeland. It is a treeless system dominated by grasses and shrubs, occuring in seldom-flooded, dry areas having frequent fires. Dominant species are saw palmetto (Serenoa repens) and wiregrasses (Aristida stricta and Aristida Soil and drainage characteristics are similar to those of pine flatwoods, but the increased frequency of fire prevents the growth of pines. The activities of man in harvesting pine trees, improving drainage, and increasing the frequency of fire have converted many former pineland areas to this system. 2. Sand Pine Scrub. Map Code 21; State Code 413. The scrub is a plant community dominated by sand-pine (Pinus clausa) occuring in well drained sandy areas, usually relic shore dunes of the Pleistocene (began 11,000 years ago) eras. Herbaceous vegetation is sparse, and patches of barren sand are frequent. Because of the elevated and. sloping landscape of this community, its soils are well drained. Consequently little free water is available for evaporation, and internal temperatures are relatively higher than those of communities occuring in lower-, flatter areas. Like the sandhill community, the scrub is fire-,maintailled. 3. Sandhill Community. Map Code 22; State Code 412. The most common variant of this is the Longleaf Pine-Turkey Oak association. The association is characterized by the co-dominants longleaf pine (Pinus p'alustris) fuLdturkey oak (Quercus laevis). Other trees, only locally .prominent, are bluejack-oak (Quercus incana), live oak (Quercus virgilliana) (usually only on lower and richer soils), and when fire has not been very frequent, persimmon (Diospyros virginiana). The Sandhill occurs on well-drained leached soils. The arboreal vegetation is open, permitting considerable sunlight to fall upon the ground and allowing air currents rather free sweep over the herbaceous vegetation. The eco.system is successional and is fire maintained. 4. Pine Flatwood. Map Code 23, State Code 411. Tr.e Pine Flatwood is one of the most extensive forests of Florida, occupying nearly 50 percent of undeveloped land. It is dominated by pine trees and derives its name from its usual occurence in areas of flat topography. The flatwoods of northeast Florida may be divided into three main types: the longleaf association (Pinus palustris -Aristida stricta), the slash-pine association (Pinus elliottii) and the black (pond) pine association (Pinus rigida serotina). The soils of this community tend to flood during the summer rainy season, due to their lack of gradient. The longleaf varient occurs in the best drained areas; the pond pine in the poorest drained areas. 5. Xeric Map Code 24; State Code 421. Generally, hammocks are woods dominated by broadleaved evergreen trees. The xeric hammock is dominated by live-oaks. Subdominant trees are bluejack-oak 116

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(Quercus incana), laurel-oak (Quercus laurifolia), Cabbage Palm (Sabal palmetto), and lesser numbers of longleaf (Pinus p-alustris) and loblolly pine (Pinus taeda). Scrubs are abundant. The xeric hammock is characteristically open, with live-oaks spaced irregularly and with many large openings in the leafy canopy. The well-drained sandy soils of this hammock and large water withdrawal through extensive feeder roots make this type of hammock particularly dry for herbaceous vegetation. Much precipitation, especially that of small showers, is intercepted by spanish moss (Tillandsia usneoides) on the trees. In addition, the arboreal vegetation permits free access of wind and sunlight, causing high evaporation loss. Although this community is titled xeric (dry) it is more mesic (moist) than. either the sand pine scrub or the sandhill conmmuities. 6. Mesic Hammock. Map Code 25, State Code 422. This hammock is characterized by an arboreal vegetation composed of magnolia (Magnolia grandiflora),laurel-oak (Quercus laurifolia), red bay borbonia), pignut (Carya glabra), American holly (Ilex opaca), water-oak (Quercus nigra), black-cherry (Prunus serotina), (Quercus virginiana),and some sweet gum (Liguidambar styraciflua) in the more moist portions Also-called the Southern Mixed Hardwood Forest ,. the ..mesi.charmnock is the most diverse upland community. The number of tree species comprising a given stand may vary from 8 to_ 35, .. ,lith the greatest diversity occuring on mesic ca.lcareous sites (sites with limestone[calcium carbonate] at or very near the surface). Drier, more-sterile areas support mesic hammocks which are dominated by evergreen hardwoods; whereas the more moist, fertile areas-are dominated by deciduous hardwood. species. While containing many plants common to the xeric hammock, the mesic hammock,is much dens.er, allowing little direct sunlight to fallon the forest floor and permitting comparatively slight winds under its canopy. Fires are infrequent, and soils are richer in organic matter and consequently have greater water holding capacity than the soils of the xeric hammock. Soils are moderately well drained to somewhat poorly drained and receive, in addition to direct rainfall, seepage and runoff from higher areas. 7. Swamp Hammock. Map Code 26; State Code 621.4. The swamp hamlllock is a still-water wetland occurring on soils which are poorlydrained but which are not subject to seasonal or periodic flooding. Soils are subject to constant seepage and have a very high water table. The red cedar (Juniperus silicicola) and cabbage palm (Sabal palmetto) are abundant. Also present are many species common to bayheads, hardwood swamp, and mesic hammock. This category also includes all still-water wetland forests not defined by the classifications: Cypress Pond and Bayhead and Beg. 8. Cypress Pond. Map Code 29; State Cede 611.1. The Cypress Pond is a still-water wetland forest occuring in areas where water is present for much of the year. This community generally occurs in upland areas of little topographic such as the pine flatwoods. It seldom occurs in the flood plains. The dominant specie is pond 117

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cypress (Taxodium ascendens). The largest cypress trees generally occupy the zone flooded most often. Trees become progressively smaller with distance from this zone. In shallower areas around the edges, competition with other species occurs, the likelihood of fire is greater and there are a large number of seedlings. Smaller cypress ponds tend to be more regular in shape; larger ponds tend to be asymmetrical and may occur in strands. 9. Bayhead and Bog. Mapping Code 30; State Code 621.6. The Bayhead or Bog swamp, is a still-water forest characteristically composed of broad-leafed'evergreen trees. Two species are generally codominant throughout Florida: the magnolia (also known as sweetbay) (Magnolia and swamp red bay (Persea barbonia). A third species is also dominant in North Florida: loblolly bay (Gordonia lasianthus). Bayheads characteristically occur in depressions of the flatwoods. They are peat-forming communities whose soils are very acid, saturated and subject to periodic flooding. It is suspected that only small amounts of water are evaporated or transpired from this community. Three variants of bog occur in northeast Florida: the herb bog, the scrub bog, and the bog swamp. For the purposes of this mapping program, the variant bog swamp is considered to be equivalent to the Bayhead. Bogs are so named because of their characteristics of developing peat and organic soils. From lowland to upland, they occur in the sequence: bog SllTarnp, shrub bog, herb bog. The herb bog, often called pitcher plant bog, is characterized by grasses, sedges, flowering and insect-eating plants. Trees are either sparse or absent. Water frequently stands at the surface or gushes from the matted surface upon pressure. The high water table and frequent fire prevent succession to shrub bog. Dry periods occur every 3-8 years. It is during such. drought periods that the surface becomes quite arid, meager peat accumulations oxidize, and fire may occur. The shrub bog is characterized by dense masses of evergreen shrub vegetation, seldom exceeding 25 feet in height. Shrubs include: titi (Q.yrilla lP.), black titi (Cliftonia monophylla), rusty black haw (Lyonia ferruginea), fetterbush (Lyonia lucida), large gallberry (Ilex coriacea), cinnamon clethra (Clethra alnifolia, Celthra spp.), dog-hobble (Leucothoe red choke berry (Aronia arbutifolia), along with assorted bluberries, azaleas and sometimes saw palmetto (SerenoL repens). Some shrub bogs may have little diversity and be dominated by a single species, most frequently Black titi. The soil is nearly always moist, with the water table at or near the surface. Soil moisture during non-storm periods is provided by groundwater seepage, usually from higher areas. During very dry periods lightning may start fires which will consume peat to the depth of the water table. 10. Wet Prairie. Map Code 31; State Code 641.2. The wet pralrle, sometimes called freshwater meadow or shallow fresh marsh, is dominated by a herbaecous cover of grasses, sedges and herbs, in varying proportions, and may also contain scattered shrubs and small trees. Common species are maiden-cane (Panicum hemitomon), cordgrass (Spartina bakerii), spike rush (Eleocharis cellulosa) beak rush (Rhyncospora tracyi), 118

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St. Johns wort (Hypericum fasciculatum), spider lily (Hymenocallis swamp lily (Crinum americanum), yellow eye grass (Xiris elliotti), sedge (Cyperus The general appearance of the prairie is that of an overgrown field. The wet prairie occurs in areas of low topographic relief and receives water from rainfall and from runoff from higher, nearby areas. It is regularly flooded by fresh water and remains wet to moist throughout much of the year. Its soils have a thick organic layer and have high water holding capacities. 11. Freshwater Marsh. Map Code 32; State Code 641. The freshwater marsh is a herbaecous community, adapted to prolonged periods of flooding. Many freshwater marshes are dominated by one or several species. The fresh marsh is usually considered the union of two subcategories of marshes: the shallow marsh and the deep marsh. The shallow marsh is often dominated by sawgrass, with common species,Maidencane (Panicum hemitomon), spike rush (Eleocharis cel1ulosa), common reed (Phragmites communis), cordgrsss (Spartina bakerii). Cattail (Typha spp.) usually occurs in permanently wet areas. The soil is usually saturated during the growing season, and it is often covered with six inches or more of water. The deep marsh is dominated by immersed grasses, particularly cattails. -Other species-include arrowhead (Sagittaria water lily (Nymphaea (Pontederia lanceolata), arrowroot (Thaliageniculata) and other aquatic forbs. The soil is covered with three to six feet of water during the growing season. Both variants occur around ponds, canals, sloughs and in depressions amoung the pine flatwoods. This mapping unit does not include the category Wet Prairie normally considered a subset of the classification Freshwater Marsh. 119

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Appendix E. Water Sampling Data Data for various water quality parameters are included for the l5-week sampling period for all of the sites sampled. Also provided for each site are the mean and standard deviation of the parameters analyzed. A table of summary statistics is also included for the overall creek system. For reference, a listing of the chemical and biological analysis parameters is included prior to the data tables. 120

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Chemical and Biological Analysis Parameters Nutrients TKN (mg/l)-N NH3 (mg./l)-N NO,) (mg/l)-N (mg/l)-N (mg/l)-P Ortho-P (mg/l)-P Cations/Anions K (mg/l) Na (mg/I) Hg(mg/I) Ca (mg/l) SO I. (mg/l) Cl'-+(mg/l) Organic Hatter TOC (mg/l) BOD (lUuj'l/\ 5 b 121 Biological Parameters 3 Chlorophyll-A (mg/m ) Total Coliforms (colonies/100 ml) Fecal Coliforms (colonies/100 ml) Fecal Streptococcus (colonies/100 ml) Physical Parameters Flow (q) (cfs) pH (units) D.O. (mg/l) Temp (CO) Turbidity (JTU) Alkalinity (mg/l) Conductivity (fl mhos/em) Visibility (em) Color (CPU) Suspended Solids (mg/l)

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STU RET CDI)f. !Ill!! HnSTDYH CRtEK BIOLUSICAL Al!l) CHEMICa DATA lflm !Ill!! UEEK HUMBER 1 ltll!! DaTE 21 ll/S!) !!Im STAR fIELD INDICATES HD DATH IHtlt !tim PARMETER DESCRIPTIDn SITE I 2 SITE t SITE 5 122 H.JlO 5.NO l!l!ltltllllllltlt If!!lililHHi Itll IIll ltltlallUHt 6.801) 51.700 IIlm!!i!IlIHHt O.46Q 0.062 II!! liliIIlBt IDi O.5115 1.200 2.1-120 lt5.4t)O 3l.j.801) 1!.540 11.350 l.1QO le.N') 15.900 !H!WUflllH
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lHHt l-HJGTDYH CRE'J{ E:IlJlDGICAl RiiD CHEMICAL DinA lHHt Hlnt IiEEK HUMBER 2 IBm DATE 2/11/8Q STAR FIELD INDICATES HO DATA li'lHt IBm STOREr WDE PARAMETER DESCRIPTIOH SITE i 2 SITE i SITE i 5 10 TEtIPERATURE (C)............ &1 STREAtt rUilJ (CfS).......... 26.f.I'I& 70 (JTU). ..... ...... 3.]00 72 VISIBILITY (M).. ........... SO CtrLnR (FC UHITS) .... ...... q5 (UMHDS/CH).... 170.QOO J>j$ lIISSlliJIf]) DXYGEN (tlG/D.... 8.500 3HB.fib-X!1b1I..) .... ; . (STHHDARD UNITS).. ...... 6.700 (HS/L AS CACU3). 5ll):tlAin!)Ei) SDLIDS
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iBm lelHl flOGTuUil CREEK BI[lU]GIGAL IJfEK iRHiBER j lilil* birr!: 211 B/SO lna1 RHl) CHENICr'lL l)i1TA l<1::'?< RBi litH! STltR FIELD nmICfHES HU DAm STURET CUDE H TEMfmATURE (C)............ 61 STREhH FlGY (CFS). ..... .... 23.750 70 (JTU)...... ...... 72 nSmILITY (li)............. l:!lHHHHHB!lt SQ CULaR (PC UHITS) .... ...... 1.vOv q5 C!1l.!l)i]CTIUITY wmmSICtD .. ,. i55. oo ]O l)ESUlJ,IED i1xYGEH (I1G/U.... Q.6"Q 3.H, BB;) (flGiU................. iW PH (gYRHDfllU> llHITS).. . 7. 5i!Q Ljiv HiG/L AS CM;ll]). 61. 6')0 ;'j]:; ;l:t.;'SPEMI)!) SOLIDS G\G/L L. 6.400 lHHU!SIL AS t/) ........... Q. 037 .,15 IW2 HlSlL AS H) ........... O. (lOS 6Z5 TtN (nGJL AS H) ........ ,.. 6]Q1E12tl':a3 (MG/L AS in ....... (liO 66 ll-P[ll; (mill M jl). . . 0.250 -p (i'iGlL r,s P>..... 1. 6110 6HQ roc UlS/L AS C)' ..... ,.... 35.301) qgC,"LCIUl1 (I'$/L nS eli)...... 37. fOI} li27iiM;HEIi.ili fiS Nt; L .. .. 2. B'jO 'm :-.mm.mJHHHt

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lilill lHBl HUSHlY}! CREEK BliJUIGICflL flli!) CHEMICAL DATA lH<1< liiHI WEEK iHHlBER 4 lHH< ;./').7/90 lHa! llllll SmR FIELD HO DAm SHlRET C@E DEtCRIPTIlJll SITE 1& 2 SITE .1 SITE 5 SITE t l)l IV m ........... 61 snm'li'! rlfjlJ (crs>. ........ 70 TUf$ITITY (JTll). .......... 7Z VISIBILITY OiL ........... B Cffi.ilR (PC ........ .. !j5 CU}IDUCTIlJITY (UHHuS/Ct!) ... nXYGEH (OG/L) ... :llv-f;[1) {nb/L}. l;C>QPH(STi1HDflRD UHITS) ....... 4io (HG/L AS CACil). 53" SUSPENDED SOLIDS (l1GiL ) .. 6HHHJ {l1(;tL AS In .......... 6i5 1m2 H1SiL AS N) ........ 625 AS ii) .......... 63Q NU2!NflJ (f1G/l AS M) ... 0- Uo lJ-ffl1t 01G/L nS P>' ........ 665 TOTflL-f!(l'iG/L AS P) ..... roc 3Sll! 2.000

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HamlfJH CREEK 8IDLflGICnL AHl) CHEMICAL Dl'ITA IllS, ium !lEEK EUliEtR 5 l:iBli IBm DME 3 Fl /'130 lHH< liiHi STflR FIELI) IH1HGflTES HO DATtI cnm:: Pi1Ri'lIiETER DHClUPHGN SITE 1} 2 SITE if 9 SITE i 5 SITE i D1 SITE \i Dli 10 TEliPFJBTUR (C) ........... 6j. STl{HH1 FUl\l (erS) ......... 70 TU@ITITY (lTV). ......... .. 72 lJBIBILITY (in ........... .. (PC UHlT$) ......... q5 CDMlltlCTIUITY ) 3.57;) 5.OV lHilHHiIHHHt ae.vo) H2.i)(l;J 11).vOI ) L$7 o.tJvQ 3.2(1) O.So.) 0.072 1.710 1.601) 1.620 2().000 2a.SN 11.220 1.370 16.001) lili IHHilHllHt IiIHHHH:BH* IlIHHillliiHm IllmlHHBHHt lilHilllmlilHt 12.QOO R>l1\li iJ.::Wi IiIHBHBHHH! (;i.GOO 130.000 lJ .320 52.300 3.200 0.049 v.v')] 1.6r{1 fl.W> Q.260 19.100 n.lOO 1.600 l.S}) 2.7'10 lJ.NO 7.500 IilHHilBBBH! !H!J:ii':lHHHHi 7.00') IiliillHiJ:ilHlIi LI.IYI) lHIRIiIil:HilH1 Fi.OOO lB.OQQ 7.301) 3.520 5.90'> 33.50\) 6.Bv,) 0.035 0.002 O.5 0.022 0.010 v.1M 1.1.61)0 2td!) 0 1.220 7.'-IR'1 9.650 13.200 17.500 lii:lil:tlHHilH! lHilmJ:iIHilill liiHllllilHHilt lHUHHHHBH!

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HH* HDGTiJJJH CREK f;I[llDGICAL aN!) CH!1ICtll DAHl Ulm IJEEK NUI1E: R 6 IHilt DfiTE 3/11/8t) 111m STAR r:m.l> INDICATES NO DATA IBm !iV-I! STlJRET ClJl) PM1Al'lETER DESGIUflTIDH SITE t 2 SITE i 4 SIn: I 5 SITE i 1>1 SITE i 04 10 TD1PERATURE (C) ........... &1 STREAN FLDU (erS) ......... 70 TiJIHIITUV (JTU) ........... 72 IJISIDIlITV Oi>. ........... 8Q Cfitl1l< (PC UHITS) ........ .. 'i5 CIJUCTIIJITY UNITS) ... '" l{tAu:nuNITi' (tfGIl AS COCfi]). 53Q S:U:!."'PEHi'JED SDLIDS (I'IGiL ) .. AS N) .......... 615HIl2 (l1S1l AS It) ......... .. 62:iTKlt UIGiL AS 10 .......... 6JOMD2/HU3 (HG/L At u) 66$ (HG/l AS P) ......... TUrru. P (IiG/l ASPt .... .. t$Q (IiSIL AS .CL ..... .... q16 Gr.l..C:Wl'l (r.G/l tiS en) ...... (tlWL IS I'I&L .. .. :r11 groIUtt (!'ISil flS. HM ....... tG7 flS iO ..... q1jQ CBU1R1!)E (lts/t AS en ..... 1il!5SIJ!.:.HITE (l'!G/L AS SDi!) ..... 31615FECnL CULlfORHS 31.67'1 HCfil STRtr. (ti?WiOvl'iU .. 322i1 Cl-!UJRIIPHYL A (UG/U ....... qij]q YAlt.R CLftRITYGlIi;lIAU ... i !1EfiltS i:'ilT UIsnu: TUBnTTIl!'! 2 i1EflUS vISIBLE TIl fltiHill1 127 IHSllHBHllllf lHHHlIBBHal 62.Q)i) 110.000 3.20Q 2.670 f.2i) 30.300 0."32 0.002 0.361 ij,lj55 9.370 0.710 16.300 1.5.800 o.:no v.qqO V120 2.]00 lj.SOO 14S0.MO l>:*fmRl>:Ull

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!:lIm H3GTOYH CREEK E;IflLDGICAL M!i) CHDntAl DATA IHB! !,lEEK HUMBER 7 DATE 3/17181) IH<* *** STAR FIELD INDICATES HO DATA IHUt STlJRET ClJvE PARAMETER DESCRIPTION 19 TBlPElHITURE (C) ........... 61 STREfti1 rUlY (CFS) ......... 7Q TURSrTITY (JTU) ........... ?2 VISIBILITY (l1) ............ aQ CnLnR (PC UNITS) ......... q5 Cl:!NDU'tTIVITY (UI'IHDSlCI'!) ... 3Qv OISStitVEO DXYGEn (HG/L) ... 31Q (l1S1L) ................ fllt....... l.jivnHl1UlalY (IiG/L AS CACD3). SUSfl8ilft:!) SDLI!)S
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IUn! HDGTDlJH CREEK E:IOUIGICflL AHD CHEflICAl DATA ltmf !JED; Hlll'lf.:ER 8 IHili vATE 3125/81) lftm STAR rrElO INDICATES kil **H *HH STIlRET tilDE PARMETER DESCRIPTIUN SITE. 2 SITE i If SITE I 5 SITE i DLt 1Q (C) ........... 61 FLUV (CrS) ......... 70 TURBrrITY (JTU). .......... 72 VISIBILITY (l'I>. .......... .. gO (PC UHITS) ......... G5 CHH!)llCTIIJITY WHHDSlCt!} ... v!S";'olIJEI) <\'IbiD. .. Jio .BrlD-(i1S1D ................ lJQPH (s'T{lJiDftRl) UNITS} ...... lJH (HG/L flS CflCiID. SOLIDS (MG/l} .. 611) AS H) ......... .. AS N) .......... &25 TKlH!1Gil AS 10 .......... iH!MID3 (MGIt. AS Ii> .. fi-pnq (HSIL AS P) ....... .. 665 Tmnl P OISiL AS -P), .... 63q TLOC (liG/L AS CL .......... q16 CfllCrUn (MG/lftS CA) ...... (HGIL fiSnS) .... 981 Hft) ....... l:1J7 PDTftSSIUH O!SilAS-iO .... .. ql.jQ Cfl.tOOO CD ..... flit5 SUlFATE (l'ISIL AS S04) ..... CDLIfilRllS (lif1H!10tlU 31d15 fECnL C1lLIf!1Rl'!S 3167'1 fECAl STREP (r!?lVlwl'lU 322:1.1 CJ![lll&JlHYl A (Ui;/U ....... CLARITY (!)IG.lTfiU ... 1 liEfiHS tOT IJISIt1..E Til SOnDtf2 ilAHS.UIsrgrr TO r.OTiDr. 129 23.000 B.270 3.800 Q.170 180.0(0) 220.000 7.l.iO **l*lHl!:il!1t1t 4.6v() 85.BOO 6.000 O.01.t7 0.01Q 0.Q19 0.203 0.380 If.l50 27.600 38.800 6.110 10.010 0.770 14.1100 15.500 ]5500.000 4750.000 6,0>.000 l!llp.ltlHOO:l1t 2.090 124.000 1.000 IHSHBH!**ll 44.$00 200.000 5.500 l!lHBHHBmlf 6.50t) 1.600 0.045 0.OV2 1.216 v.VLJ v.l00 v.560 11.MO 37.700 0.6'lO If.620 15.700 20.300 1670.000 lflH
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lHH! fllJmnm CHEiiICRL DiHA IBm lJl:I]; HUMBm 9 IBm Drl IE 41 ::l!OQ lHili STtlK FIELl} INDICiHES Hn DATil iBm 1HH! STOREr COnE PARMETER DESCRIPTIDll SITE 2 SITE i tl SITE # 5 SITE 6 SITE 7 SITE 11 9 1;) Tu'lPERRTURE (C) ........... 61 STREAM FLDY (CFS) ......... 7 TURBITITY (.JTU>' ......... .. 72 VISIBILITY OiL .......... .. 80 (PC (HUTS) ......... !:is CITHDUCTWIT'I' (UrlHtlSlCrD ... 3M [}X'fGEfl ... 25,(Ii)O 322U CHUmlJPHYL A
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HOGTDUH CREEK BIULDGICAL AHO CHEMICAL DATA l.IEEK MU:lBER q Ria! IBm i'JATE "II 3/S0 Htaf STnR FIELD INDICATES Hfl DATA HHH STURH CDoE PARAMETER DESCRIPTIDn SITE I itj SITE t 1)1 SHE I 1>4 --_. __ ... -----------------------------------------------------10 TEI'lPRATURE (C). ..... 61 STRENN (LDU (erS) ......... TUR9ITITY (JTU) ........... 72 IJIsrsruTv (11) ............ M Cl.lU1R (PC UNITS) ......... q5 CnuOUCTIVITY (UHHnS/CH) ... 3t$ DXYGEN ................ tvjJj r 11 {ST AADf!R!) IJHITS).. .. (HS/l AS CfiCU3). 5J SUSffiWfIt SOLIDS (l1G/L ) .. oiQ "M1U'mS/L AS N) .......... 6iaN!l2: (iiG/LliS In ......... .. 615 (HSIL AS In ......... .. 630 ND2/Hil3 <"G/L'AS H) 660 (HGIL AS P) ......... 665 TnIflL P OIS/l tiS P) .....
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fit;l{ lHlX HOGTDul{ Cf.lEK E;IOLOGICAL MiD CHENICAL DATA 11lm lHHl lJEEK HUiiBEH 10 litm lilll:! D?TE 41 giSt> l:!l!'" iBHl STiiR HEll) IHDICATES liD DAnt l!k1:i SHIREr G!]!)[ PflRAliETER DESCRIPTIO}i 1" TEllPERfiTURE (C) ........... &1 STREAH FLDU (erS) ......... {O (JTU) ........... 72 VISIBILITY (H) ............ SO CW .. tlR (PC UNITS) ......... '15 CrlliDtJCTIvITY WliHlJSICli) ... DISSnlijED UXVGEN (Mb/l) ... Bm) (rtblL). ...... ...... 4V PH UNITS) .... ,hLKfltINITY (nG/l AS CflCIT3). SDLIOS !'filS Sl..UATE G'lG/L AS SD4) ..... 3i5<;l3nrrAL CUllflJRI1S 31&15 fECtil CaUrORftS 31679-S"TREP. -(ffPH/l00nt) .. 322i1 ft (UG/t.) ...... .. 90J')9-(O!ITi1L) ... i ti8)j'f HUT {jISI fiLt: T u BnTTTIii 2 ftEHHS Tn 8flTTGM SHE W 2 SITE i l.j SITE 5 SITE i Dl SITE i 1>4 132

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HDSTt1YH CREEK BIlJlDSICAL AHD CHEMICAL DATA UEEK NUMBER 11 PATE STflR frrLO INDICATES HU l!** Mlf STOREr COPE PflRANETER DESCRlflTIIlH SUE I 2 10 TlJ1PERATURE U] AS N) ...... 0.623 ll-Pu4 (MG/l AS P>.......... 0.630 665 filIAL P {MSIL AS P)...... O. SSQ 6$0 TDC ("G/L AS C)... ... ...... 22. BOO l116:CfllCIUfI (i'lG/L fiSCAL...... 31. 1l2?ffIiSHESIUl'i OISIlAS fIG). ... :1. 6ft) .Ifll Sm}1:urt-(iiS/L AS MM........ 0.600 to? P!.1TASSIUH (I1SA AS-Kl...... 1. 32Q 910 CHl!'.lRI!) (rlG/L ascu .. .. .. It i{oO 'i'45 SULFATE (MGA AS SIM...... 11. QQ 26000.000 31615 fECAL CllLIfI1!ttlS nlH!lfIH8!lt 3167!JrECftl STREP (flPH/lQO-l'lD. 2(lSiLOOO 31211 CHU1RB?'rI'fLAWG/t) ...... 1. tjQ {iJISITAU... 1 tiEAliS HDT IJISU:t Tn E:flnnH. .. Q!SIP.LE HlUIHTillt 10n:i1PERATURE (C). ... ..... 2i. 900 61 fUll,/(CfS).... ..... 70 TURf:lTUY-(jTU)............ 1.500 72 VISnH!.rrt (11).. ..... .... lHBHIl:tI!IHUt SO (PC UMITS) .... ...... '15 CIJUOOCTItJITY W!'lHflS/CI'D.... 150. (jOo 30t) DISSiJL\i'l)C)fff,:EH
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STI]};ET CQiIf: HlJGTlJlJH BIDUlGICiiL ilMi) CHEHICAL DATN lHHi \,lEEK NtHiE:ER 12 RJ.:'U DinE 412J/80 lHHi STflR FIELD IH&ICftlH HO Dim R!Hi liR" PARfli1ETER DESCRIPTION SITE it 2 19. 5\,)0 27.320 17.0'10 O.3HQ 263.000 185.O ? .150 1.800 7.350 65.600 2Q.2M 0.016 0.01)1 0.755 0.467 0.750 0.850 27. (1)0 55.500 lUG 16.280 1. 210 13.800 16.600 2:100.009 2.35.000 2'10.000 2.oi) 2.000 134 SITE '-I ...... ---_ ..... __ .20.000 7.6[10 5.700 0.130 16i.0'/v 210.000 3.:1.00 1. 7QO 7.350 83.900 27.200 0.248 (I.NS 0.709 0.221) Q.310 0.420 3'1.0(;0 33.500 iJ.660 7.920 0.660 12_1(\0 13.800 16531J.O'jO 437.0v'J 2. 2.000 lHm SITE :; -----,--_ .... 1tL l)!:iO 2.l130 lG.vO 0.120 21-/v.000 155.00;; 1l.900 1.500 7.0fJO 57.500 36.4'JO 0.013 0.003 I).S'!) O.23tl l.ll1jQ !xXX',>(;iX 23.llO(I 25.700 4.310 '1.Q2 0.770 19.7M 1700.00(> '1\)5.QOQ SOO.OOO 1.3')0 2.000 SITE Dll --.... --_.-26.500 O.BOO o 21.000 210.000 6.7O i Mi) S.BO'} n.iJ(jv lB.Bvv 0.203 i).QOl 0.522 v.Ov6 O.iyi) 0.260 17.400 :n.voo 0.610 6.380 O.ilo 12.300 [1.000 2iJOi) (100 S'ii) .OO 2.000 2.000

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HDSTlJYN CREEK E;I!JLDSICAL AND CHEMICAL DATA lHa! IHUt \JEEK HUMBER 13 D;nE IJ12lllS0 IBm lllil! fIELI) ItHHCftTES liD DATA IBm IHUt IBm STOREr tnDE Pi'tRAiiETRDESCRIPTIl1t! SITE I 2 SITE i It SITE i 5 SITE lj Dli 10 TEHPERATUR (C) ........... 61 FlOU (erS) ......... 70 TURBITITY (JTU) ........... 72 VISIBILITY (M) ............ S (PC UHliS) ......... tj:i Cffi./i>UCTIVITY (u!1HDS/CI'D ... !HSSllllJ) OXYGEn
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$<1(p' IlRR IUBi H!lGT[!UH CREEK tHlU1GW1L MJD CHE!HCAL DnTA lnip. IlEEK HlH'IBER 111 RAR 51 J/S l-Hill HELl) INDICtHES tiG DAHl IBm PflRANETER DESCRIPTIfiH 1.;) TEl1PfinnURE (C) ........... 61 gTRD1il FlO!) (CfS) ......... ?Ii 'f\JREIHITY (JTU) ........... 72 (tf) ............ 80 COLOR (PC UNITS) ......... Lj5 CGNPUCTIvITY WiumS/ci'D ... 3jJV DEgnUJEV l:lX'lW/ (MG/U ... 31$ SED (HG/L) ................ }1H UNITg) ..... .. (HG!L AS CACn]). 53i), SOLIDS (MG/L ) .. 611) -CibiL ..... .... 615 NIT1(HG/L flS ID .......... 625 mSA AS iD .......... 630-ND2!HOJ (MSiL H) ...... 660 u-FB4 (i'lG/L AS tiL ........ 665 TmAl P (liG/L AS P) ..... 630 TGC-(fJG/L AS C) ..... Q IIt6 OlGA AS eil) ...... '127 t"lilGHESIUM (fliLfiS I1GL ... .31 SillHUi'I OW/L fig HA) ....... ffl?" (rfG/l AS K) ..... -. CHlDRIvF: 'OiG1L AS:-.CL) .. 9iJ gUWlTE !]4) ... .. 315jJTlJTAL ClJlIfDRtlS (tlPN/1l)vflt) 316i5 fECni CnLIHlRl1S (t-lFM/lNi'iU 31679 rU:nL STRt"'P. O!PM/lI)Ol'lt,:,J .. 32211 (:}Jl[H!!]PHYL fl-(UGil) ... ... 9v3,)q .. 1 HOT iJISI&LE Tn tiulrUJ1 2 vISIBLE. TD 'fTuM SITE 3 2 SITE # 4 136 lQ. 6.310 lS.N\) '.150 146.000 22S.Q 7.lSQv 1.350 7.35\1 92.4 14.400 O.QOq O.14'l 0.310 0.370 0.500 2Q,OQO .100 1 .. ttA U.J.'V 7.7QQ 0.660 iLiOO 7000.000 1700.000 595.0il-; Q.SQ 2.0vO iH::ll lHHi lH3! SITE 5 ----_ .... -... 18.500 1.20lj ,{.200 0.12<1 t17.0M 1.65.000 S.20V 0.7vl) 6.900 61.60" It. SO\' 0.1)14 0.014 0.28Q 1.153 1.31v )(X)O<)(;{ llj.QoO 27.2fJi'> 4.58(/ 6. tj30 0.770 B.OQ9 3
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lUll! IHH! HOGHlYH CREEK SUIlDSICAL MID CHEMICAL DATA IBm \lEEK P.UIiBER 15 DATE 5/14/30 Hn* STAR FIElD INDIcaTES HO DATA l ................ PIH.Sr f)lU)flRD UWITS) ....... 410 flUfilh'ITY (IiG1L AS CAW]). 5JO SU-:;PfH!JEv SOLIDS ) .. &lQ AS N) .......... 615Nl1t (flSIL flS In .......... 625 HU (flSIl AS ,-I) ......... .. 6Jv (flS/L AS ...... 6&0 n-Pf14(I1S/LAS P) ......... 665 TllifiL P (MG/L AS-P) ..... 6SQ roc (!'lG/L AS C) .......... .. !J16Cl'li.CIUti (tlS/t AS CfI) ...... '127 i'i fIHESIUl'I OIGIL AS MG) ... .. 11,31 Slll>IllitHIJ;/LfiS HfiL ...... 'D7 PIlTASS!U!'I{ tlG/L AS iO .. .. CHL!JRI1)t (liwe flSCD ..... (HG/L AS Sfi4) ... : .. 31;';OJT!ffAt CfJurI1Rl'1S(tlPlt/lQt)rlU 31&15 fECtIl:. ClJI...IF!JRltg 316(1:f fECAL STREP. '(NPN!l(ll}!t.L .. 32'211CHU1R!JPHYL. ft-Wb/LJ ....... tjO]qq-wnTERClftRH,!,. ... snmrr CIJuE 1 !1EAH-SHflT VISIBLE HJ 2 tiEMS:lJISI:lE m BUrrill'!. iOTEliPHtR'ilIRE (C) .. ....... 61 FLLl!,i(CfS) ......... 70 TtlRE:ITIT't'(JTu) ...... ... 72 VISIBILITY (tiL ........... so (PC-UNITS) ......... '15 CrlHDUCTIlJITY . ........ 665 rUTAl P (HG/L AS P) ..... 68v Tnc (NGll AS C) ........... ilia CflLCIHi'! (MS/l AS eM ...... 927 MflbHESIUM ("S/l AS nG) .... q}l SnvIUtl (MG/L AS NA) ....... 137 PIJfflSSIUM (HS/L AS K> .... .. ql.jO (Nb/L AS CL) ..... SULFATE {MG/L AS ..... 31503 TnTAL CULlfORMS (nPH/I00NL) 31615 fECfiL COlIfDRns (HPM/IQOML) 316711 fEef'lL STREP. ctlPN/100liU .. 322.t1 CHUlRDflHYl A (uG/U ....... YATER CLARITY
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STlmET COllE liJHl IHJ{;H1IJH CREEK f:IDL!JGICtlL Ai!u CHE!1ICfiL DATft l-ilHi UEE!;: iiUl'!t:ER 15 lH2i lHH! !fATE 5!ll:/S0 IBa! Itliti SHlR FIELD INDICilTES HO DATA l1l"R PARMiETER DESCRIPTllm 138

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lilH! l!Xl! In!l! HDcrnUM CREEl: f>IDLDSICfll AND CHEMICAL DATA !am lHHl SITE STATISTICS IUil! IBH! A STnH FIELD A MEANINGLESS IBHi lHUt tiEtlH OR STflNDaRt> DElJHlTIOH lHH-1 lilil! IBm SITE i 2 SITE I 4 ---_ .... _-------_ ... STlJP.ET PARAMETEP. DATA sm. DATil STD. CooE DESCRIPTIDN POINTS tiE AM DEl). POIHTS HEftH D!). ------1 TE!iFERaTURE (C). ......... 15. 16.47 4.73 15. 17.28 LI.S6 61 FLilU 10. 3117Z.tIS 7437Q.44 10. 3i.!.501.00 61274.Ql 31615 fECflI ... CuLiFDRrfS l. SlQ.C)O 259 91 8. 26::17.50 1168,0]' JUri'{ FECfIl STREf'. ... 606.70 783.08 10. 1:J7::1.10 1'-137.36 31211 CIlLIJRDPH'tL 1\ (uS!U ....... 6. 1:45 l.OlJ 7. 1.1)1, 1.01{ l:!q3;)O CLAlHTY . DArn ST!). 1) SCRIP TII.m POIIHS HEliN DEU. PO HITS DEI.I. ----------------_._-------------11) WiPERATURE (C) ........ 15. If.I.J2 2. 22.75 0.35 61 FLUY (CFS) .......... 111. 8.J4 12. LJ1 O. ***lHil!IHt ImlilHBatn 7Q TURBITITV (JTU) ............ 15. q.S) 10.6tt 2. 15.70 11.7L I 72 VISIBILITY (n) ............. 11. 0.17 I). 1),5 2. 0.16 0.02 GO COLOR (PC UNITS) ...... ....... '13. 134.15 1:J3.1l 2 267.0f) 21J2.74 q5 crrnDUCfrVITY (UnnnS/CH} .... 15. 172.33 36.53 2. 167.50 7'-1.25 3f) OXYGEM {ub/l) .... 1'-1. 8.05 1.43 2. B.07 0.a3 31 j3Uli O'iGlu ................. S. 2.36 l.tt6 1. 0.50 PH (STANDARO UNITS) ........ 15. 7.00 0.51.1 2. 7.30 0.57 410 Alf,filIN1TY (tlG/L AS CfiCUJ). 14. 57.40 5.46 2. 23.Q5 SDLIDS (tIC/L ) ... 13. 1Q.45 10.62 13.00 l&.&f.J I.. &1Q IHl3 (l1G1L AS H) . . 15. Q.24 0.31 2 0.02 0.00 615 1m2 '::::::: 14. 0.83 0.55 2. 1).42 0.36, D-FD4 (Hb/L AS P) .......... 15. 1.23 0.3l:J 2. 0.67 0.36 665 mfAl P (liS/L AS P) ...... q 2.17 2. .EJ& Q.01 6S0 roc
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IHHt HUGTl.illlf CREEK BIllUlSICtiL ANI) CHEMICAL DftTA l:H!lt SHr STATISTICS -I!I!* A STAR FIElD TIfDICATS A NnHIHSLESS I!l!n MEAM OR STnHDARD DEVIATIOH SITE i I SHlREr CWE PflRAHETER DESCRIPTION DATA STD. HEA DEI). DAm PDHHS 10 TEHPERATURE (C) .... 61 STREhn FLDU (CFS) ......... 70 (JiO) ........... n IJ ISIElILITY (\1) ............ calN(PC .UNITS) ......... iiJctJID)OCTIVIT',.. WI1HOSlCi'!) II ISSUlJJEl) DXYGEH (I1G/U .... r.HD'"(ltGlU ............. (STHHDftRD UNITS) ....... : ASCACIB). 531} SU$PtN!)D SOlIDS (I'IG/L ) 61Q lHi3 \HStL ftS N) ......... .. AS ID ......... ,. (tlG/LAS-IO .... ; ... .. 630 Mi1VNB3-nISlL ASH) -AS-?) ..... ..,p(I'ISllAS f) ..... ; &iQTnc AS. C) ... "H "'" 'lHCftLCIllI'l 6'lS/L AS til) .. .. -ZU711lSJiESlmt fliSiL AS-l'ib.}c .. ::; -lUi SwlUi'I(tlGlL ASAA) .. : llJ? -JlllTASSrtm' (HSII... flS' 10 1f!iQCHi..iJRIuGif;ll -A.SC!.J .. d' il!-I5: nS S[!lt}; ... ;. 315' TlITfll :Cl1l1FiWtS 31<11:1 H!iiU. ClJl!fURl'tS:-P*f19tiL) J167!f PEttltSTK? (l'!?p.llO?ltr, .. 32211CHlURllPU'tt n ... .. Y-lnrn C1JlRIl't (DIGItAU ... ZflEI1ltS :v'1s:mu:-m i:tiTIM 10 rDlPERitfURE(;J ........... 61 SiREM ft.!:iY-(CfS} ... ..... 71} TU!*'tITl1V (JTIJ) ....... 71. lJXSII:!mY (11). ........... so CillnR (PC UNITS) ... ..... '15 ClJHootTIlJITY WmmS/Cl'l) ... InSSOlIFJ) OXYGEH OiS/L) ... 311) BilD fHlUHUJ nIbIL AS H) 66v IJ-Pfil.l (tiGlL flS P) ......... 665 IDTI)l P nlG/l AS PL .... TDC (Mb/L flS C) ........... '11& CM.CIIH1 (r.G/l AS eM ...... ttll l'i11GNfSIUH (I1SIL AS i'I{;>. ... snolun (NGIL AS Nfl) ....... q37 PDTASSIUM (nC/l nS K) ..... !'jtlV CHUiRJDE ("GIL AS CD ..... '1115 SUlffHE G1G/L AS SOlf) ..... J15] rml1l CDLIfilRl'fS (HPl'l1100HU fEt;m. Gi1LIfrlRrlS(fiPU/lvl'IU JUltt FECt)l STREP. (tIPH/lQOHU ... 32211 CHUiiWPilYL fl WG/L> ...... UiHH! CLARITY (DIGITAL> .... 1 MEnliS HDT TO BflTT!:m VISIBLE Til BOTftltf 2. O. 2. 2. 1. 2. 1. 12. 2. 1. ') ... 2. ? ... 2. 2. 2. 2. 2. 2. 2. 2. 2 .. 2. 2. 2. 2. 1. 2. 25.01) 1t. 2f.I S.N 3.63 0.21 Q.M 1'-15. c!) 100.00 ljq.50 7.ljQ 1. 00 Rlt!S!lfjflUi 7.20 0.57 61. 6021l. all O. SQ l:Eltl$!lfJUm 0.01 OA1 0.02 0.02 0.75 0.00 *.1a-0.10 0.66 0.37 0.70 0.32 21.W lJ.2'-1 27.!J6 8.3lJ 3.11 1.8lJ 5.S3 2.33 0.82 0.3 q;1;5 3.75 11. 25 3. all 13620.00 16300.85 1250.00 6J6.'-IO 706: Of) -776.40 1.30. -2.(1) SITE i 10 -------...: 2. 21.00 O. 25.50 0.20 2l.t2.Qv 165.QO 6.07 2. 1. 2. 2. 2. 1. L.. 2. 2. 2. 2. 2. 2. ') J.. 2. ? ... 5. ItS 6.SJ !.tl.S5 35.20 0.25 0.14 O.S!) 1.14 1.11 1.1Q 2'-l.20 23.15 3.23 8.M 1.48 2. 2. 2. 2. 2. 2. 13.50 15.25 2. 33250.00 2. 3775.00 2. 268.50 1. 1.]0 1. 2.00 140 2. O. 2. L 2. 2. 2. 1. 2. 2. 2. 2. 2. 2 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2. 1. 2. 1. i. DATA PDIHTS 2. 0. .G. i .... 2. 2. 2. 1. 2. 2. 2. 2. 2. 2. 2. 2. 2. 2 2. 2. 2 .. 2. 2. 2. ') .I.. 1. 2. 1. 1. SITE t q HEilN SITE t 11 !'lEAH 21.50 2LJ.QO 0.10 236.1)0 155.00 7. 0.75 7.2 5t!.3S 18.20 0.1)6 OA1 ti.55 O.2Q 0.33 v.87 2:1..70 25.65 2.7Q 5.17 0.3S S.SO 11.15 651.!O.Qv 1310.00 1085.00 0.20 2.00 STI). DEI}. ST!). DEI). 1.f.Jl lilHO!lf 29.70 f'ltlHilfRlili 277.1'1 77.73 1.03 lilH!lfli lum 0.23 1&.33 18.'15 v.02 0.01 0.56 0.21 0.1;5 o.]q 10.t17 6.2Q 1.lJ6 2.33 Q.'-I7 1t.39 0.'12 6307.3'1 1011.1& lilHilil:Bmli Rl!IHHtlilm

PAGE 150

HDGTUUH BIOlDGICAL fiNO CHEMICAL DATA SUE STATISTICS A STAR FIELD INDICATES A MEANInGLESS "EAa DR STAHDARD DEVIATIUN UJHI STfJRn FM!fil'lETER CODE DESCRIPTION 19 lEHPERATURE (C) ........... {'1 FLDU (crs) ......... (') TURf:ITITY (JTU>. ......... .. n i,ilmnlTY (i1L ........... (PC UHITS> .. ..... .. 'is {";I*OOC1l!JIT'f (uI1HDS/CIi), .. rl:ftGElf (l'IG'iU ... 311) -{l'!;;It> ............. -rtf. (Sf RtIDARD uttns) .... ... 41Q (MGlL AS CACll]). SDt.rnS (tlG/L ) .. _&11 ) mD{nGIl AS M) ......... 615 lllJ2 (1'It;/t flSn) .......... 62!i TKtr (HGIL AS In .......... 630ui12/fflJ3 (/'IG/L AS if> &6 vi.l-flfiit OlGA p,s p) us nrrftL-HIGILAS PL_ .... 630 TDC GlSll fiS C) .. .. .... .. 'l16 CfllCItlif(!'lSil flS eM ... ... (tlSll AS l'!G) ..... 1131 SlJl)IUi1 (ttG/lAS :NA) ; : ; iiJTPnrilSSlim (IiGiLAS K} .. ;.;. Ijl.j? ASCU ... GiG/1.. At s!J!.t); ..... 315?1 31615 n:cftL Cl:UflJRl1S-(l'iP-1VIol)iiU 31671=1 fECl'llcSTRfP. .. 32211 CHliJRIlPHYt A ....... li-? fb!mhU ... STIJRET cnDE 1 t1Ei'lffS tmT IJISIBlTfi fllIT1D1'1 2 tiiflHS VISIBLE W;.iJITrnt 10 (C) .. ........ 61 STRE.1iI fillU (CfS). ..... ... 70 (JTU) ........... 72 VHTIlIUTY (11). .......... ,. 30CDlfiR (PC UNliS) ......... (UHHDSICH) ... llISSIJUJl> !lK'tS.i1 ... 3iQ BOD (l'lb/U ................ PH (STA*DARD UNITS) ....... ALKfllIHITY (nG/L AS CACIT3). 5)Q SOLIDS (NG/t. ) .. 610 HH3 (rrS/l AS N) .......... &15 NU2 (HSIL AS U) .......... 625 TKH (11b1L AS H) ......... .. 1-!r!2/NI.lJ (HGIl' AS U) 660 ("GIL AS P) ......... &65 TaTAl F
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all HUGHlUN CREEK BIDLDSICI1L AND CHEilICAL DATN liB STATISTICS A STflR fill!) IflDICATS A liEiiifINbLESS I:!lUi MEAN fiR STnHDARO DEVItt n:OIt IHm lUHt IBm STURE! CC.flE PARAtlETER DESCRIPTION (C) ........... 61 (CFS) ......... (JTU) ........... 12 VISIBILITY (H) ............ B CnLUR(PC UNITS) ......... q:,H:r.litOOtTIIJTIV Wl'IHilS/CI'D .. 3Q9 vlSSllIJJ!) DXYGEn t:.l) SULIDS HiS-/L ) ... 619-IfHJG1SJL I1S N) ......... 615 lUll. (I'tGlL AS N) ......... 61'j -(ng;L nS ID .......... 63.)-Ul:J2IH!Il (NG![ AS ti) ..... -66Q-fl-l!@t (tlG/L AS P). ..... .. e65-iITrP.!:. P OiSlL I1S PI .. .. '6$0. TlJt(I1G/L An:> ........... %S 'Cffl..CIUI1-(M{;./t. AS, eM .: .. ... li2? nilGHEIUI'I HiG/L tiS fI!;)._ .. inlsrnmm -(IlS1L AS l-l.iI-) : to? PI1TASSrml (I'IS/l AS 10 ...... 1j1.1':)CHUfR!l)[(!1G'/l AS CD...... ql.j'jS!..UAT SiJl!l .... :. ]iSQ 31615 fECfit. ClJLlfUR/'IS (tlJWlo-)MU 3167li fECflLSTREP. (I1PIU1Qi)!tU._, 32211 ...... Q03QQ YATER ClARITY (DrbITAl) .... STURET CDvE 1l1[",*S. illii1JISIBtm BtrrTIm 2 tJANt ijlS!BtE TIl EillITrn1 -----10 (C) ........... 61 FLr;,y. (crs) ...... .. 70 TU*8ITIJI (JTU) ........... 72 UISIBIUTY (i1) ........... .. (PC UHITS) ......... 'l5