Urban pollution survey : Christiansted and Charlotte Amalie, U.S. Virgin Islands

URBAN POLLUTION SURVEY
CHRISTIANSTED AND CHARLOTTE
AMALIE, U.S. VIRGIN ISLANDS

BY

WERNER WERNICKE, P.E.

DONALD L. HAMLIN
CONSULTING ENGINEERS, INC.
P.O. BOX 5202
ST. THOMAS, VIRGIN ISLANDS 00801

FEBRUARY, 1986

This study was supported by the Government of the Virgin
Islands, Department of Conservation and Cultural Affairs,
Division of Natural Resources Management under Contract No.
PC-CCA-22-86.

TABLE OF CONTENTS

Page

Abstract I

I. SUMMARY AND RECOMMENDATIONS II

II. INTRODUCTION 1

III. THE SURVEY EFFORT 2

IV. FIELD INSPECTIONS 4

V. INTERVIEWS 23

VI. REVIEW OF OTHER INFORMATION 26

OTHER RELATED STUDIES 26

WATER QUALITY DATA 35

VII. DISCUSSION 36

MAPS & FIGURES 45

REFERENCES

APPENDIX:

A. List of Persons Interviewed
B. Pollution Survey Summary
C. Selected Other Studies

ACKNOWLEDGEMENTS

Numerous persons assisted in the preparation of this report

by providing information and their time. It is not possible

to list all those people but their contributions are never

the less very much appreciated.

We like to particularly note the extensive assistance

provided by the persons interviewed, and would like to

extend special thanks to Ms. Dinah Johnson, Division of

Natural Resources, Department of Conservation and Cultural

affairs for her tireless efforts on behalf of this project.

Special thanks to Mr. Pedrito Francois who provided much

important and useful information and who gave freely of his

time and guidance.

ABSTRACT

A sanitary survey was undertaken in the towns of

Christiansted and Charlotte Amalie. Field reconnaissance,

interviews and review of available information was used to

determine the types of.pollutants and their significance.

Found were sewerleaks, feces deposits, waste petroleum

products, trash and garbage and soil sediment. The

information is indicated on maps of each of the areas

surveyed.

I. SUMMARY AND RECOMMENDATIONS

A Sanitary survey of the towns of Christiansted, St. Croix

and Charlotte Amalie, St. Thomas, U.S. Virgin Islands was

performed in December 1985 and January 1986. The survey

revealed that low level, but chronic, pollution sources

exist in nearly all of the urban drainage basins. Sewage

from damaged sewer lines, human waste, gray water

discharges, garbage, trash, waste oil and soil sediment and

debris were found. These pollutants are dispersed over low

lying areas during flood events and are flushed into the

nearby harbor waters with every storm that produces

significant runoff.

The upland less developed watersheds, which drain through

the more developed urban areas, were not inspected. It is

possible though that those less developed upland areas where

wastewater is disposed of by septic tanks, seepage pits or

drainfields, may also contribute to coastal water pollution

due to transport of septic tank effluents by flood waters.

Significant sources of human waste sources were found in all

the watersheds surveyed. The following are the most often

responsible sources:

1. Exposed and damaged sewerlines, located mainly in guts

or drainageways.

2. Underground damaged lines by acid attack of concrete

walls of pipes, or otherwise damaged or poorly installed

lines.

III

3. Lines which are clogged with debris and grease from

restaurants.

4. Direct disposal of human feces into guts and other

areas.

The following recommendations are provided.

1. Greater care needs to be taken in the installation of

sewerlines in guts, or other locations where the risk of

damage is high. Flood flows can cause washout of

foundations and have substantial force to overturn lines.

Installation of lines in such locations needs to be closely

monitored by the Department of Public Works (PWD).

2. Many of the old concrete sewerlines which have been

damaged by acid attack or other forces, need to be replaced

on a systematic schedule. The fixing of trouble situations

as they occur is costly and results in repeat surcharge of

sewerlines with discharge of sewage into streets and storm

drains.

3. All restaurant facilities need to install grease traps

with regular maintenance of same. The opening of any new

restaurant needs approval by the Building Permits Section,

PWD, to ensure the installation of grease traps. Sewerlines

with chronic clogging problems need to be put on a regular

maintenance program to prevent the blockage of lines and

discharge of raw sewage into the streets.

4. The Division of Environmental Health, Department of

Health needs to increase its inspection effort to identify

repeated offenders who dispose of feces in a non-acceptable

method. An education-enforcement program is needed to

minimize this particular problem. Close coordination

between the Environmental Health Division and the Public

Works Department will maximize the limited resources of

manpower and equipment.

5. In order to determine the contribution, if any, of the

upland development with septic tanks, a water quality

testing effort is necessary. Spatial and temporal water

quality sampling in representative watersheds would be

needed to define the contribution of water pollution by

septic tank effluents.

General recommendations on the other types of pollutants

inventoried are as follows:

Waste oil disposal was found to be significant in one of the

watersheds in Christiansted, however, it is suspected to be

more wide spread on St. Thomas as well. A vigorous

expansion of the waste oil collection program'by the V.I.

Energy Office and stricter enforcement against such dumping

are likely to reduce this pollution source.

Graywater discharges were found in various locations. Such

discharges should be connected to the existing sewer system.

Periodic inspection by Environmental Health and PWD will be

necessary to ensure compliance.

Trash and garbage were noted in various quantities at all

locations surveyed, however, in Charlotte Amalie the problem

appeared more severe. Christiansted by comparison was

noticably cleaner in the downtown area, but in the suburbs

the trash pollution became worse. The failure to provide

covered metal trash containers, for temporary road side

storage, appears to be one of the causes of trash dispersal.

The requirement by PWD that households provide such

containers would aid in reducing the volume of dispersed

trash. Illegal dumping into guts is a wide spread practice.

A public education program and enforcement of the litter

control law would minimize this situation.

II. INTRODUCTION

In March, 1983 an investigation of waste streams from boats

at selected bays and harbors, in the U.S. Virgin Islands,

was carried out by the Island Resources Foundation. That

work indicated that pollutants (fecal coliform) apparently

originate from land based sources. The available data

suggested that pollutants were washed into harbors with

storm runoff. The task of this sanitary survey is to

identify and categorize those sources.

The required service to be provided by Donald L. Hamlin

Consulting Engineers, Inc., (herin after referred to as DLH)

under the terms of the Contract (No. PC-CCA-22-86), is

summarized as follows:

Meet with persons of organizations who may be familiar

with such pollution sources.

Literature and map research to collect existing

documented information.

The field inspection of certain urban watersheds where

pollutants are suspected to exist, and to identify and

categorize such sources.

Air photos of the study areas.

Analyze the collected data and present it in a written

report supplemented with maps.

Six urban watersheds, or principal guts, were investigated,

three in Christiansted, St. Croix and three in Charlotte

Amalie, St. Thomas. The former include the Spring

Gut-Gallows Bay watersheds, and a number of guts which drain

through Christiansted. The guts inspected in Charlotte

Amalie include Contant Gut, the Frenchtown-Altona Gut and

Kommandant Gade Gut. The limit of the study area coincides

with the water distribution and sewer collection network.

111. THE SURVEY EFFORT

To assess the magnitude and nature of the harbor water

pollution situation several sources of information were

utilized.

1. Interviews with knowledgable individuals. Territorial

government agencies which interface directly with such

pollution matters include the Departments of Public Works,

Health, and Conservation and Cultural Affairs. Persons in

those agencies were interviewed. Likewise, individuals of

sewer construction and maintenance firms werQ interviewed.

Considerable useful information was obtained, as it

represented the body of knowledge and experience of many

years by those persons. It made information available which

could not be readily observed in the on-site investigations

such as leakage of underground sewers and of pollution

events which had occurred sometime prior.

2. The literature/map research concerned itself with

available documented information. Available city sewer

maps were obtained. Such maps, however, were dated and did

not show many of the lines installed over the past several

years. A few written documents were available which

specifically address the condition of the town's sewage

collection system (Camp Dresser & McKee, 1974; 1978).

Related information of downtown storm flooding for both

towns is available in mapped form from the U.S. Geological

survey (Haire and Johnson, 1977; 1978). This flood mapping

readily demonstrated the extent of inundation of the

downtown areas and potential distribution of contaminants of

the flooded sewage system.

3. The field inspections were carried out through a

pedestrian survey of all visible and exposed drainage ways

and noting the presence and quantity of the pollutants. The

form shown on Figure. 9 is used to summarize the findings.

The completed forms are found in the Appendix. It is noted

that sediment has been added to the list of waste categories

of the contract. This was done for three reasons. First,

sediments in themselves become a pollutant which is carried

by flood waters; it is washed into flooded structures and

facilities. Two, the sediments which are deposited in the

drainage ways frequently block such drainage facilities or

significantly reduce the capacity so that flood water and

its contaminats are dispersed over a wider area, than if the

drainage way were not obstructed. Three, other pollutants

are concentrated in sediments. The on-site survey was

carried out as thoroughly as possible, however, its limits

need to be emphasized. It only represented a one time view.

Sequential or over time investigations were not done, except

in a few cases. Further, only the pollutants visible could

be identified. Underground sewage leaks could not be noted,

unless they manifested themselves through a visible leak.

Likewise, some portions of the main guts and tributary

street stormdrains were covered. Where feasible, size of

opening permitting and lacking potentially dangerous gases,

the larger storm drains were entered and inspected. This

was the case with a small reach of Kommandant Gade Gut down

stream of Bred Gade, and a portion of the downtown gut

passing by the market (Company/King Cross Streets) in

Christiansted. A further limitation to the survey was that

generally only publicly accessible areas could be surveyed.

Private property could not be freely entered upon. Where

discharges from such properties were found, they were noted.

4. An aerial photographic record was made of all the

watersheds surveyed.

The following portion of the report gives a detailed

description of the observations and findings made during the

on-site reconnaissance.

1V. FIELD INSPECTION

Three guts were investigated in Charlotte Amalie, St.

Thomas. Kommandant Gade Gut drains a portion and discharges

directly through an older part of the town. The

Frenchtown/Altona Gut is to the west of the older part of

town, however, the lower portion of the watershed is densely

developed. The same is true of the Contant Gut which is

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even further west of the old part of Charlotte Amalie. The

three watersheds drain portions of the central St. Thomas

mountain ridge which rises to an elevation of about 1,400

feet above sea-level. The mountain ride axis runs east to

west and the watersheds drain toward the south. The higher

elevations are steep sloped (50%+); at the lower elevations

the terrain is less steep. The foothills and coastal

alluvial plains are fully developed with residential and

commercial uses. For the propose of this report each of

the drainage ways are subdivided, and numbered by segments,

and are keyed to the accompanying maps. The field

inspections were carried out during December 1985 and

January 1986. All the field inspections were carried out by

pedestrian surveys.

CONTAN.T GUT (see Figure. 4)

The Contant Gut discharges into Crown Bay, St. Thomas. The

watershed basin contains approximately two hundred and

seventy acres, and much of the topography is steep sloped,

thirty percent and higher, except in the shallow sloped

flood plain near the coast. The lower reaches of the basin

are heavily urbanized With development encroaching onto the

steeper slopes. All of the development within the study

area is sewered. Below, a description of significant

findings is given as found by following the gut up-stream

from the coast. The numbering is keyed to the map of the

area.

From Bulkhead to Veterans Drive (4 lane road). Open

concrete lined channel through the MSI building materials

yard. No point discharges were observed, however, with

rainfall runoff the dust and debris found in such commercial

areas will be washed into the bay.

2C to 3C

The drainage way under the roadway is contained in two box

culverts. Upstream of the road is a parKing/loading area

for a liquor distributer (West Indies Corporation).

Pollution discharges were not observed. During flood

events, tons of debris and sediment gets trapped in the yard

area and needs to be cleaned out.

3C to 4C

Segment from Harwood Highway to gut crossing (box culvert)

of Kum .Wah Restaurant. Lower portion of channel has

concrete block walls, and a portion is covered for parking,

the rest of channel is natural. Much sediment but no

specific pollutant discharges noted; lots of trash.

Directly down-stream of box culvert (point 4-C), several

cast iron pipes (sewer, water) run across the channel

effectively blocking discharge of the box culverts. Debris

and accumulated sediment has nearly closed the culvert.

4C to 5C

Segment from box culvert to bridge/culvert at Soto Town.

Portion of channel has concrete side walls. Some kitchen

drainage, probably floor washing was noted at Kum Wah

Restaurant located adjacent to gut, however, no trash or

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other gross debris was noted. Further upstream are

discarded bicycles and garbage apparently thrown over the

fence from residences. Small base flow with aquatic life

(shrimp) noted. Close to upper bridge oil dumping,

apparently on a regular basis, takes place. A small garage

(in Hughes Laundry yard) is the apparent source.

Immediately below bridge culvert, trash and garbage dumping

increased as well as noticable sewage odors. Base flow

appeared septic, black and gray slime growth over submerged

bottom. A small box culvert (about 12"x12") immediately

below the bridge, from the west, had a trickle, but,

apparently continuous flow of highly polluted water. Heavy

slime growth existed over area where water flowed. Source

could not be found. A fairly substantial and heavily

polluted base flow discharged through the bridge/culvert

pipes from the north.

5C to 6C

Within about one hundred feet up stream of the

bridge/culvert, a 6 inch cast iron sewage pipe, broken

apart, was discharging raw sewage into the gut. It was the

source of pollution found downstream. This break had

occurred likely some weeks prior, possibly during the storm

flood flows of the fall rainy season. This branch sewer

serves a number of homes on the west bank of the gut. Base

flow upstream of the sewer break was clean with aquatic life

in the water pools. Portions of the east bank of the gut

were used for trash and garbage dumping. The road and

residences are located parallel to the gut. A few wet

patches were noted on the pavement indicating some sort of

leakage, however, the origin could not be determined.

6C to 7C

Gross pollution sources were not found. Aquatic life

present in pools. Several shacks/residences, at the extreme

upstream end, where the roadway turns, have no apparent

connection to the sewer line located under the street. The

wooden structures are on stilts and sewerlines would have

been visible. Presumably sewage is disposed of onsite,

septic tanks were not evident either. At point 7-C, the

channel gives way to steep rocky cliffs, about fifty feet

high, a rather spectacular water-fall during flood flows.

Most of the roads on both sides of the valley were inspected

with no-other gross pollution sources found. Substantial

volumes of storm drainage from Crown Mountain Road and the

contributing watershed, discharge into Contant Gut. The

areas of the watershed at higher elevations (400 ft) were

inspected. Most of the small land subdivision access roads,

as well as the main Crown Mountain Road down to the subbase

intersection (RT.30), were closely examined. Gross

pollution sources were not found. The terrain is steep,

with slopes in excess of 50% in much of the area. Soils are

very shallow, several inches to a few feet thick, over

fractured rock. Some of the area is sewered, particularly

multiapartment units, however, most of the individual

residences use septic tanks and drain fields. One of the

sewerlines is intercepted by drainage ways which have

partially undermined the supports for the pipeline.

Eventually these supports will collapse with breakage of the

pipeline as a result. Debris was found in most of the guts

where they cross the roads.

KOMMANDANT GADE GUT (see Figure. 5)

Kommandant Gade Gut discharges into the harbor across from

the Coast Guard dock. The watershed contains approximately

one hundred and sixty acres. Much of the topography is

steep sloped. The only relatively shallow slopes are found

on the alluvial fan of the town, which are completely

developed. The steeper hill sides are partially developed

and new construction is evident throughout these steeper

slopes. All of the heavily urbanized areas are sewered as

are limited areas of the steeper hill sides. The gut was

inspected for fourteen hundred feet from the shoreline as

well as surrounding areas of the watershed. Mr. Pedrito

Francois accompanied the principal investigator on one of

the inspections.

1A to 2A

Waterfront to Main Stieet, gut is covered with concrete top

with metal gratings at regular intervals. Substantial

sediment and debris fills much of the culvert.

2A to 3A

Main street to Bred Gade, gut totally covered either by

buildings or paved yards. Inspection not performed.

3A to 4A

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Bred Gade to Storegronne Gade, concrete lined open top

section, buildings on both sides Garbage, kitchen waste

and some sediment (sand/gravel) as well as a broken sewer

line noted, sewage standing in pools.

4A to 5A

Portions of the pavement lining washed out exposing sewer

pipes. The collector sewer of the area is located

underground within the gut. Sewer manhole covers are about

two to three feet above the floor of the channel, some of

the metal cover plates fit poorly. During high flood flows

infiltration into the manholes would occur. The sewer line

from the Anglican School was plugged as sewage was

overflowing into the gut from the clean out. Judging from

the discoloration of the walls, this over flow had been

occurring for some time. Further up-stream, human waste was

noted, having apparently been dumped over the wall from an

adjacent residence. Kitchen waste from the school was

found, washed down from the kitchen area. The gut at about

elevation fifty becomes steep with large exposed boulders.

A thorough walking survey was conducted of many of the

alleys and streets of the west, north and east slopes of the

watershed.

On the hill slope east of the gut (Palm Strade, Murphy Gade,

Cathrinberg Road, etc.) the visible pollutant of consequence

is trash and garbage which is stored for pickup in open

metal drums, wooden and cardboard boxes as well as plastic

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or paper bags. Trash is strewn about such collection

points. At the intersection of Nye and Bred Gade, litter

and garbage

fills the drainage gutter under a foot bridge. Inquiry with

a near by business person revealed that this debris rarely

gets cleaned out by Public Works maintenance or trash pick

up crews. Flood flows will carry such waste to the harbor.

Inspection of the main drainage way, between points 3A and

4A showed the pooled sewage noted four weeks earlier still

present. The water way down stream of point 3A is covered.

A portion of this covered gut was inspected until it

substantially became smaller making further progress

difficult. No pollution sources were found in the inspected

portion (approximately 50 feet from the opening).

Investigation of the main gut was carried up past

Cathrinberg Road. Its gradient increases substantially with

large boulders lining the intermittent water course. The

public sewer line parallels the gut, serving multi dwelling

units on the slopes above. Puddles were found in the gut fed

by a low level base flow. High nutrient levels in the water

manifested themselves through dense algae growths in the

puddles. The nutrient source could not be determined.

Trash, sinks, bedframes, appliances and other items were

lodged between boulders and trees. Inquiries of adjacent

residents indicates that sewer line breaks have not

occurred.

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A minor tributary watershed discharges from the west slope

of Bunkerhill into the main gut (location 7A). Immediately

upstream of where the gut crosses under Kommandant Gade

Vendet, there was evidence of repeated food (kitchen) waste

discharges into the gut from occupants of a structure to the

west of the gut. About one hundred feet upstream, numerous

used diapers were noted, apparently from the residence to

the east of the gut, the only residence in proximity. Those

waste deposits were dumped since the last flood flows in mid

November, which would have flushed out any prior deposits.

The streets of the east slope of the watershed contained

trash pickup stations where poorly contained garbage was

strewn about as well as leakage from pervious refuse

containers.

The vicinity of the old water catchment uphill and to the

west of Cathineberg Road showed evidence of fresh human

waste in the bush (location 8A). Judging by the numerous

trails on and around the catchment, and information from a

resident, it is possible that some squatters may inhabit the

area. Waste disposal is likely in the bush as was noted

above.

FRENCHTOWN/ALTONA GUT (see Figure. 6)

This gut discharges from north to south. The watershed

consists of approximately one hundred seventy acres,

draining the steep southern slopes of the central mountain

ridge of St.Thomas. The portion of the watershed subjected

to the sanitary survey is situated in the shallow portion of

k>

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the valley and alluvial flood plain. This gut discharges

into the western portion of St. Thomas Harbor adjacent to

the Frenchtown community.

The central waterway from its discharge point into the sea

to the approximate one hundred and fifty foot elevation was

surveyed on foot. The linear distance is three thousand two

hundred feet. The east and west valley areas were also

inspected. For ease of reference thegut was divided into

several numbered segments with the following observations

made.

1B to 2B

Tide water present throughout reach with numerous small

fish.

Water, gray and turbid.

Some sediment present in channel bottom.

Trash and floating litter present throughout reach.

A fish cleaning station is present at the harbors edge,

however, fish cleaning wastes are deposited into a trash

dumpster and fish remains were not evident in water.

The channel is stone lined.

2B to 3B

This section, about 400 feet, runs under Veterans Drive

Highway and is covered. Visible inspection was not

possible.

3B to 4B

Soil sediment is about one foot deep at point 3B and 0

feet at point 4B.

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There is a small volume of base flow in the lower

portion of the gut.

No signs of any pollutants.

The channel is lined with concrete and open at its top.

4B TO 5B

No visible pollution sources, dry and clean.

Open top rectangular concrete channel.

5B to 6B

Natural earth channel.

Stream bed erosion at lower end and sedimentation in

upper reach.

Dwellings are located close to channel on both sides.

Trash, debris, kitchen waste, garbage in plastic bags,

engine waste oil and car parts were found. These

pollutants appeared to have been dumped recently and

repeatedly The gut experiences flood flows during the

fall rainy season when such pollutants are washed down

stream. The gut is a convenient trash dumping ground for

adjacent residences.

6B to 7B

Natural earth channel with some reaches eroded, others

heavily sedimented (several feet deep). The two circular

five foot diameter culverts which pass under the road at

point 6B are partially filled with sediment and blocked at

the upsteam end with debris and sediment. The drainage way

upstream of the pipes is functioning as a debris basin, due

to the restricted flow through the pipes. Substantial

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quantities of sediment along with other debris (matresses,

chairs, roofing sheet metal, water heaters, engine parts,

etc.) has collected in the stretch from pt. 6B to 7B.

Channel erosion is found in the upper reaches. Waste oil

and trash dumping occurs at the northern end of the Mahagony

Estate development area. A car repair shop is adjacent to

the gut and is the likely source of the waste oil.

7B to 8B

A natural stream channel, no pollutants evident except soil

sediments.

The Mahogony Estate area streets showed no obvious or gross

pollution sources, except for the usual oil drippings from

vehicles. The area to the west of the Mahogany Estate Homes

and up hill is presently undergoing extensive home site

development. Most of the construction is carried out by

small building contractors, who construct one dwelling at a

time. Land subdivision has been carried up over the ridge

line. Most of the roads are dirt, some sections are steep.

Gully erosion is evident on all the steeper (10% +) roads.

All sediment is discharged into the Altona Gut where its

presence is already evident. The Altona Homes subdivision

is located on Frenchman Hill slope east of the gut. The

streets collect the surface runoff discharging it at two

principal locations at point 10B and at the low road curve

between points 10B and 9B. The subdivision streets are

paved. The following observations were made.

9B TO 10B (Following the road up into Altona Housing)

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Storm drainage discharges from the street down a steep earth

embankment into the gut. The embankment is unprotected and

erodes with the concentrated high velocity water flow. The

day of the survey, a Public Works Department road crew was

grading the earth street shoulders with loose soil deposited

on the stream bank where the street runoff will discharge.

This loose soil material will be easily eroded during the

next storm event. An apparent gray-water discharge into the

gut was also noted from a residence on the western gut

embankment, between points 6B and 7B of the gut. Uphill of

the road switch back, nearly all the road cut sections are

stablized with concrete retaining walls, with the sewer and

water lines located behind the walls. At one point the wall

and street surface was wetted with apparent sewage. Heavy

moss growth and dark staining of the concrete indicated that

this situation had occurred for some time. The source is a

probable sewer leak behind the wall. At the second upper

road curve, point 10-B, storm drainage discharges off the

road pavement in an easterly direction down a steep slope.

Severe gully erosion has occurred down the length of the

drainage way.

10B to 11B

No pollution sources found.

11B to 13B

This road section is dirt. Several lots are in various

stages of construction. One site was freshly excavated,

with no signs of erosion/sediment control. The area is also

11

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sewered. No signs of pollution, except the soil erosion was

found.

11B to 12B

No pollution sources found.

All the streets have oil crankcase drippings and spills.

CHRISTIANSTED (see Figure. 7)

The town of Christiansted, located on St. Croix's north

shore, is situated on the alluvial plains and foot hills of

several small watersheds which drain the island's central

hill ridge. Those watersheds contain approximately six

hundred acres. All of the town is sewered. The numerous

small watersheds merge into a coastal flood plain on which

the older part of the town is located. Some of the drainage

ways are paved in the developed areas and some covered in

the down town section. The guts, streets and other

accessible areas within the survey limits were inspected.

Mr. Victor Williams and Mr. David Gulliver of the

Environmental Health Division, Department of Health

accompanied the investigator on the survey. All the major

drainage ways as well as contributary and minor street

drains were surveyed. For purpose of ease of reference the

sub watersheds are labeled B through D. Gut B drains the

north slopes of Recovery Hill and flows in a channel between

King and Queen Cross Street and passes by the library; gut C

runs along Princes street, discharging at the seaplane

terminal/Watergut Homes area having drained the Peter's Farm

area; gut D drains the Herman Hill-Fredensdal area also

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discharging at the seaplane terminal/Watergut Homes area.

Bl to B3

Gut B from New Street to Company Street is an open lined

channel, ranging in width from 8 to 12 feet; of rectangular

section. Upstream of New Street it becomes a natural

vegetated channel. The only noticable serious pollution

sources were leaking sewage pipes draining the public

toilets built over the channel at the market, between Queen

and Company Streets (location B-2). Although the flow was

minor and varied with the level of toilet usage, it was

continuous. Sewage odors were noticable. Trash and debris

as well as kitchen refuse was found in the channel. Down

stream of the market (Company Street) the gut is covered.

It was followed until its cross section became too small to

walk.- The substantial flood way cross section of the

channel between Queen and Company Streets of about 15 feet

by 10 feet is reduced to a small street drain (about 5 sq.

ft.) where it discharges onto the street at King and King

Cross Streets, adjacent to the public library. Debris swept

down stream during flood flows blocks the small discharge

way resulting in flooding of the surrounding areas. Any

pollutants in the water are likewise dispersed into the

flooded areas.

B3 to B4

One of the sewerlines of Christiansted parallels the gut.

Gravity flow takes the waste water to the main pumping

station west of the town where it is pumped to the central

treatment plant. Occasional stoppage of the pumping

facility results in sewage discharge at the lower portion

of King Street (at point B-4). This event was observed on

the morning of 12-19-85. Sewage flowed out several manhole

covers and discharged into the harbor. Inquiry of workers

at the adjacent Holger Dansk Hotel indicates that such over

flows are not uncommon. Likewise during storm flood flows,

storm water would enter the sewerline through openings in

manhole covers and mixed stormwater/sewage would discharge

at other points.

Gut C.

Gut C is open and lined from Fisher to Hill Streets.

Apparent graywater discharge was observed between Hill and

East Streets. The gut is covered from Hill Street to Strand

Street, then becomes an open channel again until it

discharges into the harbor. No obvious pollution sources

were noted.

Gut D;

Gut D is largely a natural stream bed, except for a paved

section at Basin Triangle and along West Lane, adjacent to

the Water Gut Homes. Substantial soil sediment was found

deposited in portions of the gut between points D3 and D4.

At location D-2 waste oil was found to be apparently

discharged on a routine basis. The paved section of the

channel, as well as the unlined natural downstream channel

was heavily stained with waste motor oil. The source was

traced to a gas station across the street. The surface

-20-

storm drainage runs under the gas station, with several

storm drain inlets on the service station yard. It is

possible that waste oil has been dumped into the storm

drains, however, this could not be verified. Between points

D1 and D2 an animal pen is located with animal waste in the

surrounding area. The number of animals (pigs or cows)

could not be determined, however, the droppings were fairly

fresh. A minor gut flows directly through this location.

Inspection of residential neighborhoods shows that poorly

contained garbage and trash at house front pickup locations

results in dispersal of such trash throughout the area.

Garbage is set out in various uncovered containers and

plastic bags.

GALLOWS BAY (see Figure. 8)

The ,principal drainage way and surrounding area discharging

into Gallows Bay, St. Croix was inspected. The gut was

followed from its discharge point at Gallows Bay inland for

approximately 3000 feet. The watershed drains from south to

north and encompasses an area of about 500 acres. It is

situated to the east of and adjacent to Christiansted. The

following observations were made in the immediate Gallows

Bay area which may be significant relative to coastal water

quality. A dredging operation had recently been completed

of Gallows Bay, the dredge spoil was deposited on a flat

area along the waterfront. Sedimentation from the upland

watershed had resulted in considerable shoaling of the bay

with adverse effect of navigation (verbal comm. V.I. Port

-21-

Authority). The St. Croix Marine Inc, marina is an active

boatyard. The facility appears well maintained and clean.

However, the fate of some of the waste materials

particularly bottom paint scrapings, which were observed at

several locations, as well as solvents, minor oil/fuel

spills and detergents for wash downs, appears uncertain.

The general topography slopes toward the bay and surface

runoff would wash such deris into the bay. The following

are the findings of the survey going inland.

Al to A3

No pollution sources found.

A3 to A4

A gas station (Charlies Service Station) on the intersection

of Port Street and Route 83 (point A-4 on reference map) had

evidence of small scale, but chronic oil spillage from the

lubrication area. Oil was visible in the street gutter and

the service area stained with oil. Rainfall runoff rinses

the oil into the bay.

A4 to A5

Another gas station (Esso) at reference point A-5 appeared

clean with no chronic disposal problems. At bridge crossing

on route 85 (pt A-6) substantial amounts of household

garbage, car parts and other discarded materials were

found. It appears to be an ongoing situation with some of

the waste flushed to the bay during flood events. A few

hundred feet to the south of the ridge, past the Seventh Day

Adventist School, the road is unpaved and its gradient

-22-

steepens; gully erosion is evident. Sediment was noted

dispersed throughout the lower lying parts of the road.

Parts of the watershed to the east of the gut contain

residential subdivisions with sewer service. From point A-6

to A-7, along the gut, no significant pollution sources were

noted, except that at its lower end, garbage and other trash

was evident. The gut is lined with gabion retaining walls

for the length which was inspected.

A short side excursion was made into the small drainage

basin to the west where a portion of about six acres of the

steep sloped (40-50%) hill side had been totally cleared of

vegetation by bulldozing. Heavy rill and gully erosion was

evident over all the cleared area and sediment deposited in

the valley floor. It can be expected that much of this

unconsolidated sediment will be washed onto adjacent

properties and public streets and eventually into Gallows

Bay. The debris containment berms left in the stream

channel were not very effective in retaining the large

volumes of sediment.

Along route 83, (Eastern Suburb Rd) septic sewage flow was

noted in the street gutter and although the volume was low,

it was traced to the area of Fredy's Grocery. Its exact

source could not be determined as the pavement around the

grocery had been washed down. Approximately 12,200 ft of

gut and adjacent streets/drainage ways were inspected in

the Gallows Bay watershed.

-23-

V. INTERVIEWS

Interviews were held with a number of persons who have

particular knowledge of the sewerage systems or other

pollution sources in the towns. Such persons are employed

both with the government and in the private sector. In the

V.I. Government persons employed with the following agencies

were consulted.

Division of Environmental Health, bept. of Health, St.
Thomas and St. Croix.
Department of Public Works, St. Thomas and St. Croix.
Department of Conservation and Cultural Affairs
St.Thomas and St. Croix,
Virgin Islands Energy Office.

In the private sector persons in the following organizations
were consulted.

H&M Systems-Contractors and sewer maintenance, St.
Thomas.
Majestic Construction-General contractors, St. Thomas.
Cruzan Environmental Services, Waste haulers and
sewer maintenance, St. Croix.

These companies through their activities with sewer

maintenance, waste disposal or sewer and/or water line

construction are intimately familiar with some particular

aspect of waste disposal and pollution problems. The

interviews with the various individuals in both the

government and private sector, represent many man-years of

experience with the pollution problems in the islands.

Several basic causes were cited which may be responsible for

the observed pollution in the harbor. These are as follows:

Old, corroded, poorly installed and otherwise damaged
sewage lines.
Blockages in lines resulting in surcharging of the lines
with over flows at manholes.

-24-

Flooding of sewerlines.
Failure of pumping stations.
Illegal discharges of waste into storm drains.

The above list is expanded upon below and except where noted
applies to both Christiansted and Charlotte Amalie.

Leakage from sewerage lines is significant. Charlotte
Amalie has an excess of 190,000 linear feet of gravity
sewers from 6 to 42 inches diameter. Most of this system
was constructed over 25 years ago, and about 70% of those
collection pipes are constructed of unreinforced concrete
with mortar joints (Camp, Dresser & Mckee, 1978). An
identical but more limited situation exists in
Christiansted. A dual-salt/fresh water distribution system
exists in both towns with the salt water used for flushing.
This high chloride content water together with the sulfuric
acid formed by the hydrogen sulfide of the septic sewage
results in severe corrosive attack on the concrete pipes.
It can be expected that in areas where the groundwater table
is below the pipes, sewage is leaking into the surrounding
soil from such damaged piping. Recent installation of the
new waterline in Charlotte Amalie revealed numerous
locations where sewage flowed into the excavation
(Interview, Majestic Construction). Where feasible, such
leaks were repaired, however, at other locations the leaks
were not accessible. Such leakage will eventually find its

way to the harbor waters with the seaward movement of ground

water flow.

I

-25-

The blockage of sewerlines results in the backup of sewage

from manholes and any other available pathways to the

surface. The blockages result from various items and debris

finding their way into the system. The sewer cleaning firms

called upon to clear such blockages report finding all sorts

of items: clothes, gravel and sand, sanitary napkins, etc.,

as well as hardened grease from restaurants. The latter, in

particular, is felt to be responsible for the blockages in

many of the lines (Camp, Dresser & Mckee 1978). It was also

cited as a major problem by nearly all persons interviewed.

During floods, rocks, sand and other debris wash into the

pipes through breaks in the pipes and/or into manholes which

are not covered or have their covers torn off during floods.

Many of the sewers, as well as the manholes, are situated in

the guts or stream channels with manholes which are

inundated during flood flows. When such blockage occurs,

sewage is dispersed into the streets and surrounding areas

finding its way into the harbors.

Several direct sewage discharges into drainage ways have

been reported although those situations were terminated.

H&M Systems indicated- that when cleaning the covered drain

on Guttets Gade, which drains the Savan area of Charlotte

Amalie, a number of sewers were found discharging into the

storm drain. Those sewers were sealed. This situation

occurred several years ago. Several months ago, a few

sewage discharges into one of the Christiansted storm drains

were terminated by the Division of Environmental Health. A

-26-

chronic problem in St. Croix over at least the past 10 years

has been with one of the city's main sewage pumping stations

(the L.B.J. station in Richmond Estate). Frequent failure

of the pumps results in sewage backup and discharge into the

downtown streets near the harbor. The Department of Public

Works has contracted for the correction of this problem with

the installation of new and differently designed pumps which

are expected to be installed within the next few months.

The dumping of waste oil by some service stations and

garages appears to be significant particularly on St. Croix.

Dumping into the gut was found in one location on

Christiansted and also on a minor scale in Charlotte Amalie.

Specific information is provided in the field inspection

portion of this report.

VI..REVIEW OF OTHER INFORMATION

A. OTHER RELATED STUDIES

In recent years pollutants in storm runoff (non-point

sources) have been recognized to be significant and focused

upon by waterquality-pollution abatement regulatory agencies

and investigators. While many such investigations and

studies are site specific and may not be directly applicable

to the situations in the Virgin Islands they never-the-less

provide related information which can be useful. Solutions

to water quality and pollution problems in other areas may

be useable as a model, with appropriate modifications. A

list of five different investigations is given below

followed by an abstract of each. This listing is by no

-27-

means exhaustive. Each of those reports provides references

to numerous other related investigations.

1. Coastal Pollution from Septic Tank Drainfields (Duda,
et. al., 1982).
2. Oil and Grease in Urban Stormwaters (Stenstorm, et.al.,
1984).
3. Lead Analysis in Urban Dust on St. Thomas, U.S. Virgin
Islands, (Brown, 1985).
4. Control of Stormwater Runoff in a Rural Area
(Katz,1980).
5. Storm water pollution control: Best management
practices (Finnemore, E.J., 1982)
A. Improved street cleaning in San Jose, Ca.
B. Land development Regulations, Montogomery County,
MD.
C. Storm water Pollution Control Bellevue, WA.

A brief discussion of each of the above follows. The

abstracts and conclusions of some of those reports are also

given in the Appendix.

-28-

1. COASTAL POLLUTION FROM SEPTIC TANK DRAINFIELDS

Wet weather and dry weather sampling is utilized to

monitor densities of coliform bacteria in waters

draining residential areas of coastal North Carolina.

The bacterial levels are compared to different densities

of unsewered residences in each watershed and the

limitations of the developed soils for assimilating

septic tank effluent. An analysis of the data

implicates septic tank drainfields installed in

unsuitable soils as a major source of contamination of

these shellfish waters. In order to reduce the threat

to public health and the multimillion dollar economic

loss to the fishing industry, several options are

presented for rehabilitating concentrations of failing

septic tank systems and for modifying overdesigned

drainage systems that carry the contamination directly

to shellfish waters. In addition, several common sense

management practices that minimize the delivery of

bacterial contamination to estuarine waters are

suggested for use in siting future coastal residential

development.

The area of investigation has a number of similarities

to the Virgin Islands. The development of the coastal

areas has drastically increased in the past two decades.

(All land areas in the Virgin Islands can be considered

"coastal' due to the relatively short distances from

any point on land to the coast). The North Carolina

land use investigated was all residential, as is much of

the Virgin Islands. A high percentage of the soils in

both the North Carolina study area, and in the V.I. are

poorly suited for septic tank-drainfield type of sewage

disposal (Rivera, 1970). Both areas have wet and dry

seasons though, the total precipitation,

transpiration/evaporation rates are different. Other

conditions which are different are: Much higher water

consumption in N.C. (ground water is readily available)

and hence greater volumes of waste water. Densities of

development in the N.C. study area were significantly

less (the highest had one drainfield per two acres)

while in the V.I. the lowest density zoning (R-l allows

a-two unit dwelling per one half acre, or two drain

fields per acre). The salient points of that

investigation relative to the V.I. are: That after

storm events, fecal bacterial surfaced with rising

watertables and were carried to coastal waters via the

surface drainage systems. Fecal coliform bacteria

densities in coastal waters were found to increase 50

times the level prior to such storms. This condition is

analogus to the V.I. (particularly St. John & St.

Thomas) where shallow soils over bedrock are rapidly

saturated during the wet seasons and steep slopes carry

surface runoff rapidly to the sea. While in the N.C.

experience the adverse effect of pollution (and threat

-30-

to public health) manifested itself through shellfish,

which are consumed by humans, in the V.I. the potential

threat to Public Health is oriented to water recreation

which is continuous throughout the year at most of the

islands beaches. Pathogenic bacteria and viruses are

much greater (100-1,000 times) in bottom sediments than

in the overlying water. The risk factor to humans in

the water may be small under normal circumstances,

however, after storm events, with discharge of land

runoff into coastal waters the risk to Public Health may

be greater.

2. OIL & GREASE

A study of oil and grease in urban stormwaters was

performed on a small watershed in Richmond, Calif., with

the objective of determining the amount of oil and

grease discharged into San Francisco Bay. Five sampling

stations were selected at various places in the

watershed that were indicative of specific land uses,

and runoff from seven storms was sampled and analyzed.

The results of the survey indicated that oil and grease

concentration was'highly dependent upon land use,

ranging from 4.1 mg/L in residential areas to 15.3 mg/L

in parking lots. A statistical analysis of oil and

grease and storm characteristics showed that oil and

grease concentration was independent of all storm

characteristics, except that mass of oil and grease

discharged was proportional to total rainfall.

Qualitative analysis of the oil and grease by gas

31-

chromatography indicated that it most resembled used

automobile crankcase oil. Several samples showed

evidence of spills of specific compounds. A simulation

of management techniques indicated that a 90% reduction

in discharge from commercial properties and parking

lots, which represented only 9.6% of the total surface

area, would result in a 53% reduction in total oil and

grease discharge. Growth simulation predicted a

potential 27% increase in discharge if 5% of the

watershed were converted from open land to commercial

property.

Other investigations, including the Richmond California

study, have shown that oil and grease carried in storm

runoff principally originating from vehicles, are major

contributors of oil and grease to ocean waters. The

work by Stenstorm (1984) covered a 2.5 sq.mile land

area, which approximatelyy the same area as the Tutu

Basin on St. Thomas) in terrain is similar to the V.I..

The area is adjacent to the coast and the terrain is

hilly, climatic conditions though are significantly

different. The mass pollution was found to be highly

dependent upon land use. Commercial areas and parking

lots had mass oil and grease loadings 10 times higher

than equivalent size residential areas. It was also

determined that the total (mass) oil and grease

discharged into receiving waters was related to the

total amount of rainfall, a moderate-first flush effect

was noted. Monoaromatic hydrocarbons have been
k,

-32-

regularly found in the tissue of shellfish and fish and

open waters of San Francisco Bay and are suspect in the

decline of the fisheries of the bay. In as much as

identical activities and use patterns (parking lots,

garages, commercial areas) exist in the Virgin Islands

as in the Richmond study area, a tentative similarity

can be drawn as to the pollution loading from grease and

oil into the harbor waters. Although the total mass

loading would be less due to the relatively smaller

watersheds draining into the harbors.

3. LEAD INVESTIGATION ON ST. THOMAS

An investigation of lead concentrations in downtown

Charlotte Amalie by Brown (1985) indicates that a direct

and significant hazard does not appear to exist to

humans. However, lead concentrations in dust in close

proximity to heavily traveled roads is approaching

elevated levels. Lead along with other pollutants is

washed off streets and other surfaces to be discharged

into the harbor. The cumulative effects of such lead

accumulation in the harbor or possibly in aquatic food

chains has not been investigated.

4. CONTROL OF STORMWATER RUNOFF IN A RURAL AREA.

A bathing pond in Mashamoquet Brook State Park, in

Connecticut, was periodically experiencing high fecal

coliform concentrations. Upon investigation it was

determined that the source was principally from surface

runoff from agricultural fields on which manure

-33-

spreading occurred. Some of the stream water quality

tests though did indicate human pollution sources, as

fecal coliform/fecal streptococci (FC/FS) ratios greater

than 2 were found. Storm water routing was used to

minimized pollution of the bathing pond during periods

of anticipated high fecal coliform concentrations. The

storm water was routed past the pond. Coliform

concentrations in the stream varied predictably with

time after rainfall events.

5. IMPROVED STREET CLEANING, SAN JOSE, CALIFORNIA

The city of San Jose, in 1976, undertook a 2 year study

of the effectiveness of street cleaning to reduce

pollution loading from runoff of city streets. The

study found that such cleaning can be very useful in

controlling street solids and heavy metals,

particularly in heavy traveled areas. The dimension of

the pollution impact from heavily metals and total

solids upon receiving waters in the Virgin Islands has

not been established, with the exception of some

information on lead by Brown (1985). Also the relative

proportions to other pollutants is not known, except

that sediment loadings from land development in the

watersheds are likely to be much greater than street

solids, based on information from the field surveys.

6. LAND DEVELOPMENT REGULATIONS, MONTGOMERY COUNTY MD.

Substantial pollution loads are attributed to storm

water runoff including suspended solids, biochemical

-34-

oxygen demand, nitrogen, and phosphorus, among other

pollutants. Commercial land uses have the highest

concentrations, particularly lead and zinc. Such land

uses also generally have greater percentages of

impervious areas than less intense developed uses

resulting in larger volumes of runoff. Those high

concentrations with higher runoff rates result in

significantly greater pollution (mass per unit area)

loads. Montgomery County has adopted land development

regulations which have the objective to maintain storm

runoff levels to redevelopment conditions. Various

on-site and offsite strom water detention facilities are

utilized. Significant reductions in downstream

sedimentation and pollution loads are realized with

implementation of such storm runoff controls. The

Virgin Islands has had earth change control regulations

(soil erosion and sediment control) since 1971,

however, severe flooding, erosion, sedimentation and

related pollution problems exist. The existing law has

significant potential to reduce pollution loading from

newly developed areas.

7. STORMWATER POLLUTION CONTROL, BELLEVUE, WASHINGTON

Rapid development of watersheds in Bellevue, Washington

had resulted in severe runoff problems including

flooding, erosion, stream sedimentation/sitation and

water quality problems. In response to that situation a

basin wide utility was established which developed a

master drainage plan and set goals to preserve natural

streams, protect wet land environments and reduce

flooding and related damages. Public education resulted

in voter approval to finance the effort through property

tax related to the type of land use or development.

Both private and public properties are assessed and

taxed. The program is successful in its objectives.

Public awareness of the program has resulted in reduced

waste dumping into drainage ways and catch basins as

well as improving neighborhood control of pet wastes.

The key components of the Bellevue experience are a

rational comprehensive approach in the storm water

pollution situation, public acceptance and support and

an independent user oriented means of financing. It

provides a successful model which may be workable in

other regions.

B. WATER QUALITY DATA.

Available Natural Resources Division marine water quality

data was reviewed for Charlotte Amalie harbor since 1979.

The vessel waste control plan of 1983 (Wernicke, Towle) had

reviewed the data up to that point in time.

-36-

The data collection program covers seven stations within the

inner harbor on a once monthly collection basis, however,

since 1980 the data gathering program has been less than the

monthly schedule. During 1980 ten months saw data

collection, 1981 eight months, 1982 one month, 1983 four

months for most stations, 1984 one month and 1985 four

months, although more may have been collected during the

latter part of the year.

The same situation is the case on St. Croix (Verbal comm. M.

Gilnack NRM/DCCA). Due to the paucity of water quality data

available for the years since 1980, it was not possible to

establish any meaningful correlation between rainfall/runoff

events and harbor water quality.

It is recommended that the water quality monitoring program

be brought to a full operational level with a sampling

program sensitive to rainfall/runoff events. Then any

correlation between water quality and surface runoff can be

clearly identified.

Vll. DISCUSSION:

Six urban drainage ways and related watersheds were surveyed

for obvious and visible pollution sources which may

contribute to the high fecal coliform counts noted in harbor

waters of Christiansted and Charlotte Amalie after

rainstorms. Budget limitations prevented the sanitary

survey of all the urbanized areas of the two towns, however,

the areas which were surveyed are sufficiently similar in

land use patterns so that the findings can apply to the

entire town areas.

Sources of fecal coliforms are of both human and animal

origin. A distinction between the two sources can be made

based on the fecal coliform to fecal streptococci (FC/FS)

ratios. Ratios of FC/FS greater than 2 indicates that human

sources are probable. The current NRM/DCCA water quality

sampling program does not include such differentiation thus

this additional information is not available.

In addition to the fecal coliform sources, the scope of work

also included the identification of other pollutants

including:

Human waste deposits.

Garbage and trash.

Gray water discharges.

Soil sediment.

Soil sediment was added to the original list of the

contract, due to its prevelance in the guts and more so its

effect upon the dispersal of pollutants by blocking the

storm drains and sewerlines. Pollutants are generally also

concentrated in sediments.

The survey findings represent a narrow time window. It is,

of course, possible that at other times greater or fewer

pollution events occur and at different locations. Thus the

findings of this survey should be viewed as generally

representative of the type of pollutants inventoried. The

field surveys of the drainage ways and contributing urban

-38-

watersheds did confirm that sources ofohuman based pollution

(sewage, direct discharges of human waste) exist in all

cases. Animal wastes were found in one of the Christiansted

guts. In some watersheds such as Gallows Bay, sewage

discharges appeared minor, in other locations, such as

Contant Gut and Kommandant Gade Gut, the events were major.

Raw sewage was found discharging at both the latter

locations for apparently some time, several days, perhaps

weeks. Intermittent sewage overflows occur in downtown

Christiansted, a situation which is being resolved after

many years. Likewise, significant sewage overflows occur on

a regular basis in Gallows Bay, although the field survey

did not find evidence of such occurrences, except for a

minor localized discharge in the Eastern Suburb Street

gutter.

The interviews with a number of knowledgable individuals

greatly expanded the information base regarding urban

pollution. Based on discussions with personnel of the St.

Thomas Division of Environmental Health, the original field

survey was modified. Damaged sewer pipes had been reported

to be a frequent problem in Contant Gut. This gut and

watershed was examined to reveal one of the worst incidents

of pollution a broken six inch sewer discharging raw

sewage directly into the gut. The broken ends of the cast

iron pipe had rusted indicating that the pipe had been

broken for some time, likely during the heavy rainfalls in

the fall. The pipe is situated directly in the floodway

-39-

subjected to the full force of flood waters. Erosion of the

pipe supports is also likely. Damaged sewer pipes were also

found in other guts.

Based on the experience of personnel in the Department of

Public Works and sewer cleaning firms, blockage of sewage

lines by grease and other objects and the poor physical

condition of the lines are some of the principal causes of

sewerline surcharges (over flows) and leakage into the

surrounding surface and subsurface areas. These situations,

though, had been previously reported by Camp-Dresser & McKee

(1974; 1978). The lack of grease traps by restaurants are

cited as the principal cause for the grease buildup and

blockage of lines. When blockages do occur, lines are

cleaned. A regular cleaning-maintenance program though, is

not in effect. The leakage of sewage from the old damaged

concrete pipes, as well as other broken and otherwise

leaking pipes, appears to be extensive in the older

portions of the towns. Camp-Dresser & McKee reported that

nearly 70% of the sewerpipes in Charlotte Amalie (in 1977)

were of the old unreinforced concrete type which have been

shown to have badly deteriorated due to sewage acid attack.

In Christiansted the situation was similar when surveyed in

1974. Although expansion to the system has taken place in

the intervening years, much of the old system is still in

place except where total failure required replacement. To

what extent the leaking sewage affects the harbor water

quality is not clear. One reasonable assumption is that the

-40-

hydraulic gradient of the ground water table is towards the

ocean and that sewage flows in that direction. Any

substantial inland ground water pumping however would

reverse the water table gradients causing flow towards the

well. The existence of such conditions have not been

investigated in the study areas.

A. HUMAN AND ANIMAL WASTES:

Direct discharges of human waste were found mainly in the

Kommandant Gade Gut watershed. Three locations were

identified (see Figure. 5). In at least two of the

locations a moderate storm flow in the gut would wash the

waste downstream and into the harbor. This likely had

occurred during the flood flows in November 1985. Those

waste deposits are renewed continuously.

The feces deposits were not of great quantity. They were

however, exposed and subject to rapid dispersion by animals,

insects, flood waters and other agents. The surrounding

area is also completely urbanized and heavily populated.

The risk for disease transmittal under such circumstances is

significant. Further, since this condition has been found

to exist at the time of the survey, it is reasonable to

assume that it occurs, more or less, at other times.

Concentrated animal wastes were found in the Fredensdal Gut

(Gut-D, Figure 7) in Christiansted. The location of the

waste in the flood way would ensure its transport to the

harbor by flood waters. Of course in all locations the

ubiquitous pet wastes are present likewise to be washed off

-41-

with rain storms. Such animal waste would also account for

fecal coliform contribution into the harbor waters.

B. WASTE PETROLEUM PRODUCTS:

Waste oil grease (automotive type) was noted in relatively

minor quantities in some of the guts. Like trash, such

waste oil and is occasionally and conveniently discarded

into a nearby gut. The one exception to the above was that

substantial quantities of waste oil were found discharged

into the storm drain at Basin Triangle, Christiansted. The

apparent source was a gasoline service station in that area.

The Virgin Islands Energy Office operates a waste oil

collection program where by a contractor is employed to

collect and dispose of waste oil from facilities such as

service stations. Interviews were held with both the

Director of the Energy Office and representatives of the

waste oil collectors on St. Thomas and St. Croix. The waste

oil, once collected, is tauen to the VI. Water and Power

Authority facilities where it is burned as fuel. The

collection service is free, ie., the cost is borne through

the V.I. Energy Office. The representative of that office

indicates that 13 waste oil generating facilities

participate in the project, 5 on St. Croix and 8 on St.

Thomas. Approximately 15,000 gallons of waste oil is

collected each month. An interview with the representative

of the waste oil collection agency on St. Croix (Beagels),

indicates that significant illegal dumping, of waste oil

occurs on that island, and that the collection program needs

-42-

to be expanded. The finding of the oil dumping at Basin

Triangle supports that conclusion. On St. Thomas the waste

oil dumping problem does not appear as serious as on St.

Croix. Never-the-less, appropriate action should be taken

to terminate the waste oil discharges which were identified.

C. GARBAGE AND TRASH:

Household garbage and discarded items of every description

were found throughout the survey areas'- particularly in the

stream channels. Much of it is deliberately deposited or

otherwise washed downstream from other locations during

prior floods. Garbage was also found noticably dispersed at

road side pickup points. Containers of various materials

are used, usually without covers. Plastic bags, paper and

cardboard containers are easily torn by animals with

consequent dispersal of the contents. In nearly all

instances the collection of the garbage from those pickup

points occurs on a regular basis no substantial buildup of

garbage was found. The pickup service though only stops at

designated locations. Any overall roadway cleanup is

inadequate to effectively deal with the trash/garbage

dispersal problem. At other points, particularly where

trash and garbage is dumped into guts or down the

embankments, natural cleanup occurs when flood waters wash

the debris down stream. The V.I. Code does provide for the

use of covered durable containers for the temporary storage

of garbage for curbside pickup. The enforcement of this

-43-

provision would go a long way towards miminizing the

unsightly dispersal of garbage and related cleanup costs.

D. GRAYWATER DISCHARGES:

This type of wastewater discharge was found at most of the

guts inspected although its volume was not large. In nearly

all instances it appeared to be occasional kitchen or

laundry discharges. A graywater discharge is defined to

include any household type waste water without the addition

of human or animal waste. The National Plumbing Code,

adopted as a standard in the Virgin Islands, prohibits such

discharges. Although such discharges may appear benign, the

waste does impart gross solids and biological oxygen demand

on any receiving water. There is also no guarantee that

only harmless materials are discharged. It is thus the

wisest policy from a public health standpoint to isolate any

such waste stream from our environment.

E. SOIL SEDIMENT:

The presence of soil sediment was found in all the guts

surveyed. In some cases it nearly renders useless the storm

drainage works. Past storm events (floods of April 1983 and

November, 1984) due to their significant damage had resulted

in Presidential Disaster Declarations by which federal funds

would be available for restoration of damaged public

facilities. Examination of those records (Federal Emergency

Management Agency (FEMA)-Damage Survey Reports) has shown

that damage due to washouts and sediment (debris) clean up

-44-

amounted to over one half million dollars during the 1984

storm. Nearly all the sediment/debris was deposited in

drainage works and sewerlines. The deposition of sediment

and debris in drainage ways results in a reduced capacity to

convey flood water, and such repeating occurence

necessitates costly cleanup. Clogged and inoperative

sewerlines have the additional consequence that the sewage

will surface and flow exposed through streets and yards.

Such conditions not only result in harbor pollution but also

appreciably increase the risk of disease exposure for the

general population.

A parallel study on soil erosion and sedimentation is being

carried out by this firm. It is showing that accelerated

erosion and sedimentation may be one of the most

environmentally damaging consequences of development, and

certainly necessitates a costly and repeated cleanup effort.

It can be expected that as more of the steeper slopes of the

island are developed that the erosion/sediment and related

flooding and pollution problems will increase in severity.

LIST OF MAPS AND FIGURES

FIGURE NO.

TITLE

LOCATION MAPS ST. THOMAS

LOCATION MAPS ST. CROIX

WASTE CATEGORY MATRIX

MAPS OF SURVEY AREAS CON

MAPS OF SURVEY AREAS KOM)
GADE

MAPS OF SURVEY AREAS FREN
ALTONA

MAPS OF SURVEY AREAS CHRI

MAPS OF SURVEY AREAS GALI

POLLUTION SURVEY FORM

TANT

4ANDANT

ICHTOWN/

STIANSTED

,OWS BAY

e row 7u!N7 1. ..;I
FRENCHTOWN/ALTONA GUT
CONSTANT GUT o

P. P t...

t eertr
V P 0 + Re nJ

Pr // / ', Pt FI GURE 1 1
Prove K LOCATION MAP
ST./ Tl T\ 0Carol T T 1 l
oD <-I-""^ ,ST. THOMAS.VTRGTN T.qC.ANnc

~1

est~nt -~ GALLOWS BAY GUT

C49 Gallows Ba e
~ N IO N _~r- t F or 66
\rrpT IS ~ 7 ~
I / ran _e -lt o n,~

_J L
L. Gr /, >': -Kc~ r-17- '

a r I
E -AldershHifi e 3~ di ar .t

_' 20 x~sn
/ --CC C~~ C ~vs.2llerw,- 'Z /

t IIng
I '- P"Ik
e:; -- i-I/- ~ ~I
.2010

~?5t2-s 62 {~hg'b~~hoce ,a\ -prnG5-5-de 611 .EnIRit 1177~I -/fl

3",3
S'L
jit S -h d -e

,'` :SJ111 L r

.J C ~ ~ '\ ( t85~ -Sp~~~d n!~r :J -Sp in /! r

lie 0C)L6god 0-
Graai ,C C ,- ~ = &o

1r. I_ i
Catbrioll r -

Ruins 0 F U 2
---- K-T: LOCTIO MAP, ~
-, ", ST ROI VIRG-INi ISLND
Sd Hill :I N
-t ~8~i -i --r Longford
Granald ,
Ruins!, ? FIGURE 2

_eLOCATION MAP

~~ ST. CROIX,VIRGIN ISLANDS

CHARLOTTE AMALIE

r t r r

0

en
tn

_______ L.

BROKEN
SEWER LINES

OTHER SEWAGI
DISCHARGES
X x x X X

FECES

x
ANIMAL WASTE

Sx x PETROLEUM
X PRODUCTS

HOUSEHOLD
GARBAGE AND
TRASH

GRAYWATER
DISCHARGES

SOIL SEDIMENT

________ L _____ I ____________

> r
Htri

o

0
::E

>
mtl

__

CHRISTIANSTED

SITE LOCATION: CONTENT GUT
ST. THOMAS,VIRGIN ISLANDS

SL: BROKEN SEWER LINES
H: HUMAN WASTE
GD: GRAYWATER DISCHARGE
G: GARBAGE
S: SEDIMENT
0: OIL
A: ANIMAL WASTE

O 500FBE
I I

SCALE

FIGURE 4
N-

PC-LUTION SUR
iu t ~

SITE LOCATION: KOMMANDANT GADE
ST. THOMAS, VIRGIN ISLANDS

SL: BROKEN SEWER LINES
H: HUMAN EASTE
GD: GRAYWATER DISCHARGE
G: GARBAGE
S: SEDIMENT
0: OIL
A: ANIMAL WASTE

) 500FFME'

SCALE

SITE LOCATION: FRENCHTOWN/ALTONA GUT
ST. THOMAS, VIRGIN ISLANDS

SL: BROKEN SEWER LINES
H: HUMAN WASTE
GD:GRAYWATER DISCHARGE
G: GARBAGE
S: SEDIMENT
0: AIL

A: ANIMAL WASTE

0 500FEE
I S

SCALE

FIGURE 6

POLLUTION SURVEY

Dona/ Lfambn
CONSULTING ENGINEE RS C.
alunr

*rcuo

I I

--

-//,7 $ ,' SITE LOCATION: CHRISTIANSTED
~ *ST. CROIX, VIRGIN ISLANDS

hi:-N ----------------------~
SL: BROKEN SEWER LINES
G H: HUMAN WASTE

GD: GRAYWATER DISCHARGE
SG: GARBAGE
ST, S: SEDIMENT
0O: OIL
A: ANIMAL WASTE

DEN DAL-- o C.M

SCALE "NSULTING ENGINEERS, INC
~:'fif ~
.> ,,J/ (JIV~
~~ FIGU~r 7
t rJcG:N-
C OIIINSRE
0 ~ ,O 10Q~P~aE
I~re- 2 .an
SCALE COSLTC NGNES C

SITE LOCATION: GALLOWS BAY
ST. CRIOX, VIRGIN ISLANDS

SL: BROKEN SEWER LINES
H: HUMAN WASTE
GD: GRAYWATER DISCHARGE
G: GARBAGE
S: SEDIMENT
0: OIL
A: ANIMAL WASTE

0 500FEET
SCALE

Fl

-- POLLU

cc

__

A

SL: BROKEN SEWER LINES
H: HUMAN WASTE D ....SIO- ......---
i

GD: GRAYWATER DISCHARGE
G: GARBAGE j FIGURE 8b
S: SEDIMENT

0: OIL _- POLLUTION SURVEY
A: ANIHU MAL WASTE !DATE REVISION

S.DESiGN flona f L.4 7 OAE
SORA N OW NO.
CONSULTING ENGINEERS, INC.
CHECKED S Tho U S Vrr slands

Figure #9

POLLUTION SURVEY

Gutter: Date:

Charlotte Amalie I Christians

Surveyed:

ted EL

Types of From To
Pollutants COMMENTS

Broken Sewer
Lines

Evidence of
Sewage

Human Waste

Sewer Manholes
Which May Flood

Graywater
Discharge

Garbage

Sediment

Oil

Septic
Discharges

Other

REFERENCES:

Camp Dresser & McKee Inc, May 1978,

"Report on infiltration /inflow analysis for the

Charlotte Amalie sewerage system."

Haire, W.S. and Johnson, K.G., 1977,

"Floods of November 12, 1974 in the Charlotte Amalie

area, St. Thomas, U.S. Virgin Islands;"

U.S. Geological Survey Water-Resources Inv. 76-91

Haire, W.S. and Johnson, K.G., 1978,

"Floods of November 11-13, 1974, in St. Croix, U.S.

Virgin Islands;"

U.S. Geological Survey Water-Resources Inv. 77-136

Camp Dresser & McKee, Inc., Feb. 1974,

"Report on infiltration/inflow analysis for

Christiansted, St. Croix."

Wernicke, W., and Towle, E.L., March 1983,

"Vessel Waste Control Plan for the U.S. Virgin

Islands;"

Island Resources Foundation.

Duda, M.D., and Cromartic, K.D., Dec. 1982,

"Coastal Pollution from septic tank drainfields,"

Journal of the Environmental Engineering Division,

ASCE Vol.108 No EE6

Stenstrom, M.K., Etal., Feb. 1984,

"Oil and grease in urban stormwaters.," Journal of the

Environmental Engineering Division, Vol, 110, No.l.

Brown, D.R., 1985, "Lead analysis in urban dust on St.

Thomas, U.S. Virgin Islands,"

Accepted for publication in Atmospheric Environment.

Katz, P.B., et al.,

"Control of storm water runoff in a rural area,"

Paper presented at the 1980 National Conference on

Environmental Engineering, specialty conference,

NY,NY, July 8-10, 1980. Published by the American

Society of Civil Engineers.

Finnemore, E.J., Oct. 1982,

"Stormwater pollution control: Best Management

Practices," Journal of the Environmental Engineering

Division, ASCE, Vol. 108 No.EE5.

Rivera L.H., et al., 1970,

"Soil Survey Virgin Islands of the United States",

U.S. Department of Agriculture, Soil Conservation

Service.

APPENDIX

A: LIST OF PERSONS INTERVIEWED

B: POLLUTION SURVEY SUMMARY

C: SELECTED OTHER STUDIES

APPENDIX:

A. List of Persons Interviewed

Department of Public Works

Lincoln Oliver, Asst. Commissioner, St. Thomas.

George Suarez, Asst. Commissioner, St. Croix.

Edsel Hanser, Dir. of Utilities, St. Croix.

Estrid Hartman, Dir. of Utilities, St. Thomas

Department of Health, Division of Environmental Health

Ms. Moolenaar, St. Thomas

David Gulliver, Asst. Dir., St. Croix

Donald Lee, Inspector

Victor Williams, Inspector

Private Organizations

Joseph Klein, Majestic Construction, St. Thomas

Richard Washburn, H&M Systems St. Thomas

Howard Beagels, Cruzan Environmental Services, St.

Croix.

POLLUTION SURVEY

2/10/86
1/7/86
Gutter: Knmmanr1nt Date: 12/5/85 Surveyed: WW/PF

Charlotte Amalie [L

Christiansted F

Types of FromShoreline To 200 foot elevation
Pollutants COMMENTS

Broken Sewer Broken PVC line from house connection
Lines Sewage pooled in bottom of gut

Evidence of Blocked sewerline from All Saints School
Sewage overflowing

Human Waste Noted at several locations

Sewer Manholes Low elevated manholes in gut which could be
Which May Flood inundated during flood flows

Graywater
Discharge Found at several locations
Discharge

Poorly contained garbage becomes scattered at
Garbage several locations. Other items such as sinks,
bedframes, appliances in gut

Sediment

The lower reaches of the covered channel contains
much sediment

Oil None found

Septic
Discharges None found

Other

Frenchtown/
Altona
Gutter:

Charlotte Amalie I

POLLUTION SURVEY
2/10/86
12/17/85
Date: 12/12/85
Date:

Surveyed:

Types of From Shoreline To 200 ft elevation
Pollutants COMMENTS

SS At Altona Homes project leaking pipe
Lien r behind retaining wall
Lines

Evidence of None found
Sewage

Human Waste N
None found

Sewer Manholes Not apparent
Which May Flood

Graywater Noted at several locations
Discharge

Garbage

Sediment

Oil

Found throughout most of channel along with
larger items such as mattresses, chairs, engine
parts etc.

Substantial channel erosion.and sedimentation.
Watershed under development with dirt roads
and construction of houses. Steep slopes.

Found at several locations. Deliberate dumping
at a street side auto repair shop.

Septic
Discharges See under "Broken Sewer lines"

Other
Other

Christiansted II

POLLUTION SURVEY

2/10/86
12/27/85
Gutter: Contant Date: 1/2/86 Surveyed: WW

Charlotte Amalie [El

Christiansted [L

Types of From Shoreline To 400 foot elevation
Pollutants COMMENTS
Six inch castiron line broken u stream of

Broken Sewer
Lines

Evidence of
Sewage

Soto Town discharging directly into gut, probably
several week old, heavy downstream pollution

see above

Human Waste None found

Sewer Manholes None found
Which May Flood

Graywat6r None found
Discharge

Garbage Trash and garbage found in most areas of gut

Sediment Substantial sediment in various portions of gut

Oil Waste oil dumping into gut from auto repair shop

Septic Noted in several locations of gut, possible
Discharges resurfacing of upstream sewage discharges

Other

' N
FI :

i

I

I

.N

Other sewerlines located in or crossing drainage
ways. Some of the line foundations may fail resulting
in broken lines

POLLUTION SURVEY
2/12/86
Downtown/ 12/19/85
Gutter: Several Date: 1/8/86 Surveyed: WW

Charlotte Amalie E1. Christiansted [X

Types of From ShnrtE-inp To 100 annt elevation
Pollutants COMMENTS
Leaking sewerlines from public toilets built over
Broken Sewer channel at the market; otherwise none specifically
Lines found. Old and broken lines leak into groundwater
and seep into harbor.

Evidence of Repeated breakdown of main pumping station results
Sewage in sewerline surcharge, sewage flows down streets
into harbor. (1)

Human Waste None found

Sewer Manholes Downtown manhole flood during major storm events,
Which May Flood pollutants distributed through flooded areas.

Gray-water Noted at one location
Discharge

Garbage Garbage and litter in many streets; garbage stored
curbside for pickup in containers which are torn
Sby -nimaIs- or break down during rain
Sediment Noted at many locations

Substantial waste oil dumping into storm drain system
Oil at Basin Triangle.

Septic
Discharges None found

Entire downtown area floods during major storm events
Other due to inadequate storm drainage structures, sewers
likewise flood and pollutants are dispersed.

(1) The pumping station (LBJ station) is currently
undergoing major repairs to eliminate that condition,
work estimated to be completed in six months.

I

Charlotte Amalie F

Christiansted l

Types of From Shoreline To 100 foot elevation
Pollutants COMMENTS
Broken Sewer None found
Lines
Evidence of Flow in Eastern Suburb Street gutter
Sewage
Human Waste None found
Sewer Manholes Portions of lower watershed becomes inundated
Which May Flood during flood events
Graywater None found
Discharge
Garbage At various locations dumped into gut

Sediment

Severe erosion of bulldozed hillside
Substantial volumes of sediment dredged from Gallows
Bay

Oil Waste oil spills at gas station
Septic None found
Discharges

Other

scraped bottom paints,oil spills, detergents at
St. Croix Marine facility. Such wastes will be washed
into bay with storm runoff. Repeated blockages of
sewer lines results in surcharging and flow onto
streets.

POLLUTION SURVEY
1/8/86
2/12/86
Gutter: Gallows Bay Date: 12/19/85 Surveyed: WW

COASTAL POLLUTION FROM SEPTIC
TANK DRAINFIELDS

By Alfred M. Duda' and Kenneth D. Cromartie2

AssmAcTr: Wet weather and dry weather sampling is utilized to monitor den-
sities of coliform bacteria in waters draining residential areas of coastal North-
Carolina. The bacterial levels are compared to different densities of unsewered
residences in each watershed and the limitations of the developed soils for
assimilating septic tank effluent. An analysis of the data implicates septic tank
drainfields installed in unsuitable soils as a major source of contamination of
these shellfish waters. In order to reduce the threat to public health and the
multimillion dollar economic loss to the fishing industry, several options are
presented for rehabilitating concentrations of failing septic tank systems and
for modifying overdesigned drainage systems that carry the contamination
directly to shellfish waters. In addition, several common sense management
practices that minimize the delivery of bacterial contamination to estuarine
waters are suggested for use in siting future coastal residential development.

CONCLUSION

In the last century, annual oyster harvests in North Carolina have been reduced
by 95% (9). While exploitation played some role in this decline, the pollution
of shellfish beds has been a major factor. The continued construction of unsew-
ered residences on poor soils in coastal areas poses a stiff challenge to the en-
vironmental engineering community. With repeated violations of bacteriological
water quality standards occurring in 20% of all shellfish waters, North Carolina
commercial fishermen have suffered extensive economic damage, and serious
threats to public health have been created by the documented levels of bacteria
and suspected levels of viruses. The results of this investigation support several
important observations:

1. A significant positive correlation existed between dry weather and wet
weather levels of fecal and total coliform bacteria in waters draining coastal
residential areas and increased densities of septic tank drainfields in the wa-
tersheds. Due to the high bacterial densities recorded during dry weather and to
the seepage of effluent into drainage ditches observed during the investigation,
much of the contamination was attributed to septic tank drainfields installed in
soils with severe limitations rather than simply surface runoff.
2. Of the six tidal watersheds examined in this investigation, the two partially
developed watersheds with septic tank densities less, than 0.15 drainfields per
acre had acceptable water quality and were open to shellfishing; one suburban
watershed with an estimated 0.17 drainfields per acre was half closed to shell-
fishing; the remaining three urban watersheds with densities greater than 0.25
drainfields per acre were highly contaminated by bacteria and were totally closed
to shellfishing.
3. Extensive artificial drainage improvements have been made in these resi-
dential developments to circumvent state regulations prohibiting the use of con-
ventional drainfield systems in soils with high water tables. Evidence was pre-
sented to illustrate that contamination from septic tank effluent reaches these
ditches and tile drainage systems and is then efficiently delivered directly to
freshwater creeks or tidal waters. Depending on soil texture, hydraulic gradient,
rainfall, and proximity to ditch and tile drainage networks, the effluent and as-
sociated viruses or bacteria may either: (1) Flow laterally through soil to nearby
shellfish waters; (2) move laterally along the hydraulic gradient (as seepage dur-
ing dry weather and as a pulse or slug flow during wet weather) through soil
to nearby ditch or tile drainage systems that channel the contamination to tidal
waters; or (3) be "stored" in the surficial water table until the effluent surfaces
with rainfall and flows to nearby ditch systems.
4. The use of existing common sense management practices was advocated
for correcting existing problem areas and preventing future contamination. These

common sense practices focus on these principles: (I) Maintaining sufficient rural
areas in each coastal watershed to provide dilution water so that the capacity of
tidal waters to assimilate the pollutants is not overloaded; (2) preventing pollution
source areas from being hydraulically interconnected to freshwater creeks and
tidal waters; and (3) implementing revisions to regulations involving horizontal
and vertical separations and permit approval authority so that conventional sys-
tems are used only where they can truly function properly.

If the use of such common sense practices is not achieved in coastal areas of
the southeast, water quality standards violations and threats to public health will
continue. In the event this happens, the designated use of these waters should
be downgraded to reflect the polluted nature of the water rather than the clean
water needed to support the multiple uses to which citizens have been accustomed.

---- ~ ~ ~

STORMWATER POLLUTION CONTROL: BEST
MANAGEMENT PRACTICES

By E. John Finnemore,' M. ASCE

ABssTcrT: Nonstructural and elementary structural stormwater pollution con-
trol measures, known as best management practices (BMPs), are found ca-
pable of excellent urban runoff pollution control. Besides costing less than
structural measures, which to date have received much attention, BMPs often
provide multiple benefits. Case studies describe four successful and very prom-
ising BMPs. Their approaches, implementation, and resulting performance.
costs, and impacts are provided for future planners and designers. In Bellevue.
Washington, an innovative stormwater utility has effectively administered
Bellevue's stormwater management program. In a regional approach at Mont-
gomery County, Maryland, many source controls have minimized erosion and
removed most pollution from urban runoff at moderate costs. Near Lake
Tahoe, in California. planning for stormwater management aided by erosion
controls has prevented tremendousoincreases in sediment yields. At San Jose.
California, extensive studies revealed that improved street cleaning will ef-
fectively control total solids and heavy metals in runoff.

SUMMARY AND CONCLUSIONS
Best management practices (BMPs), which curtail the development of storm-
water pollution or treat it at its source, clearly show great promise. In just the
last few years, preliminary cost and performance information has been collected
from demonstration and full-scale applications of BMPs to the control of urban
stormwater pollution. This information can and must be used to guide future
pollution control programs in other locations. Case studies and comparisons of
four projects representing very promising practice, at Bellevue, Washington;
Montgomery County, Maryland; Lake Tahoe, California; and a study at San
Jose, California; have better defined the potential of BMPs for controlling storm-
water pollution.
This study has suggested a general approach to selecting BMPs for new sites,
aided by comparative cost and performance information like that in Table 2.
An optimal BMP program for urban stormwater pollution control will usually
have the following three key features: (1) A combination of various BMPs, which
together are best suited to the local pollutants, conditions, and control objectives;
(2) wherever possible, the measures used will also have needed uses and benefits
in areas other than water pollution control, such as flood control and recreation;

and (3) institutional measures and means (ordinances, financing, education, en-
forcement, etc.) that are tailored to support the program objectives and the fea-
tures just mentioned.
The environmental impacts of urban BMPs were found in the case studies to
be considerable; damage to stream and lake environments was held to a minimum
in spite of upstream development. Improved street cleaning greatly reduces the
emission of dust particles into the atmo-shere (18), a major additional benefit
besides its esthetic and public safety benefits.
The urgent need for cost-effective pollution control measures, their present
early stage of development, and the difficulties of generalizing in this techno-
logical area make professional evaluations of current practices indispensable. To
extend the reported range and conditions of application of representative BMPs,
individuals responsible are strongly urged to publish case studies as soon as new
measures have proven themselves in regular service. Documenting the operation,
costs, and performance of particularly promising BMPs, as was done in this
paper, will enable engineers and others to use actual case study information to
plan and design efficient future measures to control urban stormwater pollution.

OIL AND GREASE IN URBAN STORMWATERS

By Michael K. Stenstrom,' M. ASCE, Gary S. Silverman,2
and Taras A. Bursztynsky2

Aasnrcr: A study of oil and grease in urban stormwaters was performed on
a small watershed in Richmond, Calif., with the objective of determining the
amount of oil and grease discharged into San Francisco Bay. Five sampling
stations were selected at various places in the watershed that were indicative
of specific land uses, and runoff from seven storms was sampled and analyzed.
The results of the survey indicated that oil and grease concentration was highly
dependent upon land use, ranging from 4.1 mg/L in residential areas to 15.3
mg/L in parking lots. A statistical analysis of oil and grease and storm char-
acteristics showed that oil and grease concentration was independent of all storm
characteristics, except that mass of oil and grease discharged wps proportional
to total rainfall. Qualitative analysis of the oil and grease by gas chromatog-
raphy indicated that it most resembled used automobile crankcase oiL Several
samples showed evidence of spills of specific compounds. A simulation of man-
agement techniques indicated that a 90% reduction in discharge from com-
meral properties and parking lots, which represented only 9.6% of the total
surface area, would result in a 53% reduction in total oil and grease discharge.
Growth simulation predicted a potential 27% increase in discharge if 5% of the
watershed were converted from open land to commercial property.

CONCLUSIONS

Oil and grease pollution from urban stormwaters is an important and
growing water quality problem. The most significant single identified
factor that affects oil and grease pollution in urban runoff is land use.
Runoff from commercial properties and parking areas contained an oil
and grease concentration nearly three times higher than runoff from res-
idential property. Since commercial and parking properties usually have
higher rational runoff coefficients, the mass of oil/grease pollution per
unit area for these types of land uses will typically be more than 10 times
greater than pollution from open land or residential areas. The hydro-
carbon load factor for residential property in this study was 142 Ib/sq
mile-in. rainfall (9.80 kg/sq km cm), dramatically lower than the hydro-
carbon load factor for parking property of 3,460 lb/sq mile-in. rainfall
(239 kg/sq km cm).
Oil and grease pollution was found to be independent of all storm
characteristics, with the exception of total rainfall. Rate of rainfall, days
between storm events, and length of storms had no significant effect on
oil and grease concentration, although there was an indication of a mod-
est "first flush" effect.
Oil and grease concentrations were frequently greater in urban runoff
than the 15 mg/L standard normally allowed for industrial dischargers
to San Francisco Bay. Several studies have shown the presence of toxic
hydrocarbon compounds in stormwater runoff, including monoaromat-
ics and polynuclear aromatics (10,17,27). Monoaromatic hydrocarbons
have been found regularly in Bay water and in fish and shellfish tissue
(7,8,30). Whipple, et al. (28,29,30) have reported that monoaromatics may
be contributing to the current decline of the striped bass (Monroe saxa-
tiles) and other fisheries in the Bay. Thus the relatively high levels of oil
and grease found in urban runoff in this study, and the potential for
introduction of aromatics, may indicate that stormwater is a significant
pollution contributor to San Francisco Bay.
Simulation of the Richmond watershed indicates that the most favor-
able mitigation techniques would be those addressing land uses that have
high hydrocarbon load factors. For the Richmond watershed, controlling
approximately 10% of the land area could result in a 50% decrease in
hydrocarbon emission. Future development in the watershed could re-
suit in a substantial increase of oil and grease. Potential mitigation tech-
niques applicable to various land uses have been reviewed by Finne-
more and Lynard (12) and by Stenstrom, Silverman, and Bursztynsky
(26).

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