Title: Draft - Water Supply Needs and Sources Assessment - Apendix E - Consultant Responses to Proposed Evaluation Factors, August 6, 1993
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Title: Draft - Water Supply Needs and Sources Assessment - Apendix E - Consultant Responses to Proposed Evaluation Factors, August 6, 1993
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Abstract: Jake Varn Collection - Draft - Water Supply Needs and Sources Assessment - Apendix E - Consultant Responses to Proposed Evaluation Factors, August 6, 1993 (JDV Box 90)
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APPENDIX E


CONSULTANT RESPONSES TO PROPOSED EVALUATION FACTORS
AUGUST 6, 1993







APPENDIX E

TABLE OF CONTENTS




Response from Peter F. Anderson, P.E. .


Response from L.M. Buddy Blain, Esq..


Response from Peter S. Huyakorn, Ph.D.


Response from Irwin H. Kantrowitz .


Response from Vance W. Kidder, Esq. .


Response from Jerry E. Kubal, P.G.. .


Response from R. David G. Pyne, P.E..


Response from Peter J. Schreuder, P.G.


Response from Charles H. Tibbals. .


Response from Jake Varn, Esq. .


. .... ......


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77


83


88


99


103


111


117


. . . . 121


Page

59


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Water Supply Needs and Sources Assessment Project
Discussion of Proposed Evaluation Factors

Peter F. Andersen
July 27, 1993



1 UNDERSTANDING OF PROBLEM


The Water Supply Needs and Sources Assessment Project is designed by
the St. Johns River Water Management District (SJRWMD) to achieve the
following objectives:


1. Define water use needs to the year 2010.


2. Describe projected impacts of year 2010 water use needs on
water levels and water quality.


3. Define thresholds of acceptability of water level and water
quality changes.


4. Delineate areas with inadequate water resources to meet
projected 2010 year demand.


SJRWMD proposes to delineate areas with inadequate water resources to
meet the 2010 year demand by comparing the projected impacts to the
thresholds of acceptability of water level and water quality changes. The
projected drawdown impacts of year 2010 water use needs have been developed
from pumpage projections that were input to regional groundwater flow
models. The thresholds of acceptability (objective 3) will be developed
for the following water resource criteria:


vegetation
salt water intrusion
surface water bodies; and
existing legal users.







SJRWMD has developed six potential evaluation factors for salt water
intrusion and two potential evaluation factors for legal existing users.
The purpose of this report is to provide input on the reasonableness,
practicality, and legal supportability of the description of conditions
which constitutes unacceptable salt water intrusion and impacts to existing
legal users. Comments are offered on the reasonableness, practicality, and
legal supportability of methods for measuring or predicting the magnitudes
of saltwater intrusion and impacts to legal existing users. Other
alternative evaluation factors are offered for consideration by SJRWMD.

2 GENERAL COMMENTS


Development of thresholds of acceptability for saltwater intrusion
and impacts to legal existing users will undoubtedly be very controversial.
Areas that are found to be deficient in water resources could suffer
economically because new industries or housing developments with
substantial water needs could become discouraged from locating in these
areas.
While it is important that the thresholds of acceptability be sound,
it is equally important that the projections for 2010 water use be
accurate. It is disturbing to note that "a substantial disparity exists
between the projected 1990 and 2010 water use growth estimates and the
projected population growth estimates for the same period" (SJRWMD, 1992).
This observation could result from problems with the water use database as
noted by GeoTrans (1991): "...the data base for current and projected water
use is nearly unmanageable in its current format. Cross-referencing
current and projected water use was a particularly difficult task".
Konikow (1986), in a post-audit of a groundwater modeling study, found much
of the bias between predicted and observed water-level change over a ten
year model period could be attributed to errors in the assumed total
pumpage during the prediction period.
Six salt water intrusion evaluation factors and two impacts to legal
existing users evaluation factors have been proposed by SJRWMD. It is
presumed that SJRWMD wishes to use a number of these (or other) evaluation
factors, rather than a single all-encompassing criteria, to establish the







critical use areas. I believe that several evaluation factors should be
applied, and that they should be applied in a site-specific manner. For
example, areal flow direction reversal may be important near the coast, but
may take on less importance near the western limits of SJRWMD.
It should be noted that of the six salt water intrusion factors, four
require measurement or prediction of water quality changes. The data base
for water quality is generally not as extensive as the hydraulic head data
base. Similarly, model predictions of water quality changes are generally
less certain than model predictions of hydraulic head changes. It would be
desirable to have as much certainty associated with the evaluation factors
as possible. Consequently, factors dealing with measurement or prediction
of hydraulic head changes may be most acceptable.

3 SPECIFIC COMMENTS


This section discusses each of the evaluation factors proposed by
SJRWMD and provides comments on their reasonableness and practicality.
Some comments are made regarding my impression of legal supportability,
however, most of the discussion is related to technical issues.


3.1 Salt Water Intrusion Evaluation Factors


3.1.1 Factor 1. Reversal of vertical and/or horizontal directions of
regional groundwater flow.


Presumed basis for use as evaluation factor: A regional seaward or
downward head gradient will tend to form a barrier to advective transport
of saltwater inland or upward into the production zone. Reversing these
flow directions could cause salt water intrusion to occur.


Comments: With some expansion of the description of this evaluation
factor, it appears to be a fairly good criteria. In one sense, it is not
an extremely stringent criteria. A gradient reversal is not a necessary
condition for saltwater intrusion to occur, it can be induced by merely
reducing a seaward or downward hydraulic gradient. In another sense,







however, this criteria may be overly stringent. Reversing the horizontal
hydraulic gradient in a non-sensitive area may not induce intrusion.
The possibility exists where a water resource development project
will reverse directions in such a manner as to make a positive impact. For
example, an agricultural project proposing to pump marginal quality water
(4000 mg/l) from a lower production zone where an upward gradient existed
prior the proposed use coming on line, could have positive impact on upper
zones by reversing the gradient.
The description of this factor, particularly the definition of terms,
needs to be made more clear. For example, the size of "regional" must be
clarified. Any wellfield or development is likely to cause reversal over
some finite area. The size of this area is site specific. In addition,
the definition of flow direction reversal must be carefully spelled out.
Vertical flow direction reversal is fairly clear: flow is either up or
down. However, a 180 degree change in flow direction in the horizontal
plane, as "reversal" would imply, is rarely seen in natural systems. A 120
degree change in flow direction could be critical.
With proper definition of terms and more specific description,
application of this evaluation factor on a site-by-site or sub-regional
basis may be appropriate


Ability to monitor or make projections: This would be fairly easy to
monitor, except one would have to be careful to correctly adjust for
density differences in determining flow directions. Flow direction
predictions could be accomplished with a numerical model or analytical
procedure, provided that the range of aquifer parameters was well
documented. Current basic data deficiencies include the distribution of
hydraulic head in the Lower Floridan aquifer and the competence of the
upper confining unit.


3.1.2 Factor 2. Vertical or lateral movement of the fresh/saltwater
interface


Presumed basis for use as an evaluation factor: Landward or upward
movement of the saltwater interface could cause water in neighboring wells








or surface water bodies to become salty or of lower water quality.
Landward or upward movement also causes the size of the productive
reservoir to diminish in size.

Comments: SJRWMD would have to assign some value of acceptable
movement. Virtually any development will cause some movement of the
interface as the system re-equilibrates to adjust to the new stress. This
process is generally very slow.
Most of my comments regarding this factor are related to monitoring
and prediction, which are described below.


Ability to monitor or make projections: Monitoring saltwater
interface movement could be done, however, it would require locating the
saltwater interface and strategically siting monitor wells. The current
database is fairly sparse for use in determining historical movement of the
interface with any level of accuracy. Given that saltwater interface
movement is a very slow process, monitoring is somewhat of an after-the-
fact proposition. It is unclear what recourse there would be after
movement had been detected, particularly if it occurred years after the
water use had been initiated.
Predictions on the rate and magnitude of saltwater interface motion
has a great deal of uncertainty associated with it. First, movement under
natural conditions must be established or assumed static. Second, the
boundary conditions must be accurately specified. Basic questions arise
related to this: where is the boundary in the Lower Floridan? What
hydraulic head is associated with the Lower Floridan? Where are the
lateral boundaries? Third, the database for most of these types of models
do not account for localized heterogeneity or preferential pathways that
could have a marked effect on saltwater intrusion.


3.1.3 Factor 3. Potentiometric surface elevations at or below mean sea
level in the Floridan aquifer.


Presumed basis for use as evaluation factor: Drawing the
potentiometric surface below mean sea level in the Upper Floridan could








induce flow of salt water towards wellfields or water development projects
from below or from the seaward direction.


Comments: Based on the potentiometric maps presented in SJRWMD
(1992), it does not seem like this would apply in very many areas. It does
indicate a very limited number of areas of concern on the coast.

Ability to monitor or make projections: With a satisfactory network,
areas where potentiometric levels are at or below sea level would be fairly
easy to identify and monitor. Projections could be made by numerical
models or analytical solutions, provided that the hydrologic system is
understood fairly well. Care should be taken in accurately defining the
seaward boundary condition.

3.1.4 Factor 4. Change in the spatial distribution of chloride
concentrations as follows:


a. Water less than 250 mg/l
b. Water less than 1200 mg/l
c. Water less than 5000 mg/l


Presumed basis for use as evaluation factor: Exceeding drinking
water standards, agricultural irrigation limits, and cost effective reverse
osmosis treatment limits is undesirable. It is presumed that SJRWMD wants
to maintain zones of water quality as they currently exist.


Comments: This evaluation factor seems to imply that movement of an
isochlor (contour line) will be construed as a negative impact. Nearly any
development will cause some movement, particularly in the vertical
direction.
The criteria does have some merit in that it discourages development
near the transition zone between acceptable chloride concentrations.
The wording of this criteria would have to be modified to clarify
what constitutes an unacceptable change in spatial distribution. As it








currently reads, an increase in the size of a zone of less than 250 mg/l
could be construed as a negative impact.

Ability to .monitor or make projections: Monitoring chloride
concentration zone changes could be done, however, it would require
locating these zones and strategically siting monitor wells to note
movement. The current database is fairly sparse for use in determining
historical movement of the concentration zones with any level of accuracy.
Predictions on the rate and magnitude of chloride concentration changes has
a great deal of uncertainty associated with it.

3.1.5 Factor 5. Change in chloride concentrations of water discharged
through springs or through upward discharge to the
surficial aquifer system such that unacceptable impacts
to the natural systems would occur.


Presumed basis for use as evaluation factor: In addition to
protecting groundwater resources, SJRWMD must protect surface water bodies
such as wetlands, streams, and springs. This criteria specifically
addresses the quality of water discharged from the groundwater system to
surface water bodies.


Comments: This evaluation factor would have to be reworded to
specify what an "unacceptable impact to the natural system" is.


Ability to monitor or make projections: This criteria would be
fairly easy to monitor through spring water sampling. However, it is not
clear if any changes in water quality would be truly attributable to salt
water intrusion. Monitoring of flow to the surficial aquifer by upward
leakage would be much more difficult. Since there is no natural sampling
point, as there is with a spring, direct sampling would have to be made
with wells. Indirect sampling, such as wetlands or other surface water
bodies, would have greater uncertainty associated with them. Projections
based on modeling would have the same limitations as were discussed for
Factors 2 and 4.









3.1.6 Factor 6. Degradation of groundwater quality to the extent that the
cost of treatment is not economically feasible and/or
unacceptable impacts to natural systems would occur.


Presumed basis for use as evaluation factor: This is either a
"catch-all" criteria intended to prevent loopholes from criteria 1-5 or,
taken independently, is an attempt to address the root of the water supply
management problem with a generic statement of what constitutes an impact.


Comments: This evaluation criteria has a great deal of latitude for
argument as to economic feasibility or unacceptable impacts. There may be
too much additional analysis required for the objectives of this program.
The concept of the factor is good in that it seems to promote a site-
specific analysis.


Ability to monitor or make projections: This factor would be almost
impossible to monitor because the criteria is so open-ended.


3.2 Impacts to Legal Existing Users Evaluation Factors


3.2.1 Factor 1. Decline in water level such that a change in pump type is
required.


Presumed basis for use as evaluation factor: The need to replace a
pump due to water-level decline is a costly impact on a legal existing
user.


Comments: This factor should incorporate pump level, not just pump
type. Resetting pump levels or coping with a pumping headless could be
costly.
The evaluation factor is good because pump replacement is a
measurable baseline that can be documented fairly easily. However, this
factor is arbitrary in that it artificially makes an area of users who may
have old or marginal water supply systems appear to be stressed.
Associated with this, it may be difficult to establish if a well going dry







was natural occurrence due to drought or if it truly resulted from adjacent
over-pumping.

Ability to monitor or make projections: This criteria is fairly easy
to monitor. With sufficient data, projections can be made with numerical
models or analytical methods as described for salt water intrusion Factor
1.

3.2.2 Factor 2. Change in water quality such that an additional level of
treatment is required.


Presumed basis for use as evaluation factor: Treatment costs for an
impacted existing user is an annualized expense that will often exceed
capital costs of well replacement.


Comments: This criteria by itself seems to imply that there is no
impact until a legal existing users water quality declines markedly. This
could take years to become a problem, even though it could be averted with
early detection nearby or through predictive means.
This criteria would be difficult to apply because someone must
determine if "an additional level of treatment" is required. This is a
somewhat qualitative determination that could become mired in legal
battles.


Ability to monitor or make projections: Changes in water quality can
be monitored by routine groundwater sampling. SJRWMD would have to
determine which analytes would be appropriate indicators of impact.
Predictions of changes in water quality could be made with a
numerical model or analytical procedure. However, it should be recognized
that the accuracy of concentrations derived from these types of models is
marginal. For example, the range of chloride concentrations usually ranges
from 0 mg/l in the model interior to 18,000 mg/l on the seaward or lower
boundary condition while the range of chloride concentrations that could be
critical may be between 100 and 300 mg/l. This critical range is only









about one percent of the modeled range, and which is probably less than the
predictive capability of the model.



4 OTHER SUGGESTIONS FOR EVALUATION FACTORS


4.1 Proposed Salt Water Intrusion Evaluation Factors

4.1.1 Factor 1. Hydrogeological areas of high leakance in the Middle
Confining Unit or low leakance in the upper confining
unit that have historically experienced increases in
chloride content in wells.


Basis for use as evaluation factor: Much of the cause of saltwater
intrusion can be attributed to either: 1) a loss in freshwater head, which
may result from an inability to provide leakage to the production aquifer
from above; or 2) unabated flow of poor quality water into the production
aquifer from below which may result from a poorly competent Middle
Confining Unit.


Comments: This factor recognizes the importance of confining bed
properties in controlling salt water intrusion. By looking at historical
trends in chloride content, less emphasis is placed on the predictive
ability of a solute transport model and projections of future pumpage. The
data base for locating areas of high or low leakance may be somewhat
sparse, however it is no different than that used to construct the solute
transport models. Some wording may need to be revised, such as "high",
"low", and "significant".


4.1.2 Factor 2. Areas of Historically Increasing Chloride Content In
Wells.


Basis for use as factor: Saltwater intrusion is an inherently slow
process. Much of the intrusion that will occur between 1990 and 2010 is
likely to be the result of changes in hydraulic head that have already







occurred. Therefore, if an area is currently experiencing rising chloride
content, it is probable that this trend will continue over the foreseeable
future.


Comments: This factor recognizes the different time scales that head
changes and salt water intrusion occur over. Lowered hydraulic heads are
essentially an instantaneous pressure-induced response acting against small
elastic storage whereas the movement of-the saltwater front is actually a
relatively slow flushing response acting against large pore water storage.
By looking at historical and present-day chloride data, the need to predict
chloride changes is de-emphasized. Perhaps combining this criteria with
area of large projected increases in pumpage or predicted water level
decline would be appropriate.


4.2 Proposed Impact to Legal Existing User Factor


4.2.1 Factor 1. A percent (to be established) decline in the artesian
head (difference between potentiometric surface and top
of aquifer) or water table surface at an adjacent
permitted water users well.


Basis for use as evaluation factor: A head decline results in a
decrease in the productivity of a well.


Comments: This factor is similar to SJRWMD impact to legal existing
user Factor 1 except it accounts for the probability that pump settings
will vary across a region. Rather than having antiquated or marginal water
supply systems control whether an area is considered stressed, this
criteria sets a reasonable percent decline. The difficulty comes in
determining the appropriate percent decline and the baseline from which it
is computed.


5 CONCLUSIONS
Six evaluation factors for saltwater intrusion and two evaluation
factors for impacts to legal existing users were presented by SJRWMD.









These factors were discussed in detail in terms of reasonableness and
practicality. Although none of the factors are completely acceptable, some
of the factors may be usable with modifications or clarifications. Factors
dealing with predicted hydraulic head changes were particularly attractive
because have less uncertainty associated with them than factors dealing
with predicted concentration changes. Two additional saltwater intrusion
evaluation factors and one additional impact to legal existing users
criteria were proposed in this report. -These factors, which may also not
be perfectly acceptable, offer alternatives to those proposed by SJRWMD. A
combination of the best elements of all the factors that were discussed may
be the ultimate solution to establishing final evaluation factors.



6 REFERENCES

GeoTrans, 1991. Wekiva River Basin Groundwater Flow and Solute Transport
Modeling Study: Phase III Three-Dimensional Density Dependent
Groundwater Flow and Solute Transport Model Development. Consulting
report prepared for St. Johns River Water Management District. 103
pp.

Konikow, L. F. 1985. Predictive Accuracy of a Ground-Water Model Lessons
from a Postaudit. Ground Water Vol 24 No 2. pp 173-184.

SJRWMD, 1992. Draft Water Supply Needs and Sources Assessment. October
1992. 36 pp.







L4W OrricCe
BLAIN & CONE, P. A.

l.. 4. BUO Y BLAIN 02 M^I D o0N gTOCrT
THOMAS C. CONC. JR. TAMPA, fLORIOA 13Sg
ROoDNes Y .i. I1I M. j A. 3813) 223-3alg
TaACCY v. PORTER KCS (Isa aS-a4ea
August 3, 1993




Ms. Barbara A. Vergara, P.G.
Director
Department of Groundwater Programs and Technical Support
St. Johns River Water Management District
P. O. Box 1429
Palatka, FL 32178-1429


RE: Water Supply Needs and Sources Assessment Criteria Development


Dear Barbara:

Here are my written comments and recommended alternatives concerning the potential evaluation
factors for saltwater intrusion and or determining impacts to existing legal users. I look forward
to our meeting where we will have an opportunity to discuss these.

Since ,




L. M. Buddy lain

LMB/wad

Enclosure


















71
8C"' 1 2lOkO. O0U








WRITTEN COMMENTS AND RECOMMENDED ALTERNATIVES
CONCERNING
THE POTENTIAL SALTWATER INTRUSION EVALUATION FACTORS


Factor 1 Proposed: "Reversal of vertical or horizontal directions of regional groundwater
flow."

The mere fact that there has been, or there is predicted to be, a reversal of the vertical
or horizontal direction of groundwater flow may not be nearly so significant as the
change in the rate of flow, even though there might not be a change in the direction of
flow. If an activity (pumping, draining, flooding, or injecting) is of sufficient magnitude
to cause sinifican change in rate OR direction of flow, it should be given careful
scrutiny. Even then, the resulting effect is not necessarily adverse. For example:
constructing or filling a reservoir, or injecting significant quantities of water into an
aquifer might very well change the direction of regional groundwater flow,: This might
be done intentionally to create a fresh water barrier against salt water intrusion.

Building a dam, digging (or filling) a canal, diverting surface water flow, or changing
the withdrawal quantities from a wellfield can all result in reversal of the vertical or
horizontal direction of groundwater flow. If there are enough of these activities, or if
they are large enough, they can cause regional changes.

Suppose another bad freeze wipes out the citrus industry; or a blight kills the fern
industry; or the prices of row crops are so bad that the fields are plowed under; or, are
not planted at all. Irrigation will stop. The rate of groundwater flow will be altered.
The direction of the flow might even change. Is this good? Or bad?

What about changes in the weather? These are even less predictable. There might be a
wet hurricane season or a hot, dry summer. One part of the district might be
experiencing a prolonged drought while another part is flooded. It is well recognized that
when it is wet, there is less irrigation and more drainage; when it is dr) there is more
irrigation and less drainage. It also depends on when it does rain in -relationship to
seasons and growing cycles.

There are other causes which change ground water flow. When commodity prices are
high, there is more irrigation; when prices are low, there is less pumping. When fuel
prices are high, there is less pumping. Any significant or wide-spread change in pumping
rates, increases or decreases, causes changes in ground water flow.

The change in direction of flow is not as significant as the change in rate of flow.

Recommended alternative:

Signifcant averse ateration of the rate, magnitude or direction of vertical or
horizontal groundwater flow.
72









Factor 2 Proposed: "Vertical or lateral movement of the freshwater/saltwater interface."

Both vertical and lateral movement of the freshwater/saltwater interface are important
evaluation factors to be considered. Long term trends are more significant than the actual
movement itself. Trends are difficult to determine without an extensive grid of monitor
wells, a comprehensive evaluation program, and good, long-term records. Seasonal and
cyclical variations must be carefully studied and accepted.

Recommended alternative:

Long-term trends in upward and landward movement of the freshwater/saltwater
interface.



Factor 3 Proposed: "Potentiometric surface elevations at or below mean sea -evel in the
Floridan Aquifer."

(At the risk of being severely chastized, and readily admitting that I am no hydrologist,
I respectfully suggest that) this is not an appropriate factor. A potentiometric surface
drawn down to, or even several feet below, mean sea level at a location away from the
coast may be far less threatening than a potentiometric surface drawn down near the coast
even though it may still be a foot or so above sea level. It makes a great difference
where and how high the recharge area is, how close the measuring point is to the coast
and the configuration and tightness of the confining layers.

Recommended alternative:

This factor should be omitted.



Factor 4 Proposed: "Change in spatial distribution of chloride concentrations as follows:

"a. Water less than 250 mg/1
(EPA recommended public drinking water standard)
"b. Water less than 1200 mg/1
(Upper limit for agricultural irrigation)
"c. Water less than 5000 mg/l
(Upper limit for cost-effective treatment of water
for public supply using reverse osmosis)"

Use of the criteria in subparagraphs a. and b. seems more practical than using sub-
paragraph c. New technology and energy sources may soon change the cost-effectiveness
of reverse osmosis and similar or related processes. Using specific numbers is all we have
but seasonal and/or cyclical changes do occur and must be acknowledged.

73


-Lemr: t'rA.t-Xu.T










The beginning phrase should be modified and subparagraph c. should be omitted.

Recommended alternative:

Significant, recurring reduction in spatial distribution of chloride concentrations
as follows:

a. Water less than 250 mg/1
(The maximum EPA recommended public drinking water standard)

b. Water less than 1200 mg/1
(Generally the upper limit for agricultural irrigation)



Factor 5. Proposed: "Change in chloride concentrations of water discharged through springs
or through upward discharge to the surficial aquifer system such
that unacceptable impacts to natural systems would occur."

This attempts to say too much in one sentence. How small a spring are we really
concerned with? There should be a size for springs, Rather than selecting a minimum
base flow it is easier to refer to the "magnitude" of the spring as classified by 0. E.
Meinzer. See Fla. DNR Bureau of Geology Bulletin No. 31, Spings of Florida by
Rosenau, Faulkner, Hendry and Hull.

Determining "unacceptable impacts to natural systems" caused by "change in chloride
concentrations". ."through upward discharge to the surficial aquifer system" requires
far too much speculation. Only an evaluation factor about springs should be used.

Recommended alternative:

"Significant, recurring or sustained changes in chloride concentrate ns of water
discharged through springs of magnitude or greater."



Factor 6. Proposed: "Degradation of ground water quality to the extent that the cost of
treatment is not economically feasible and/or unacceptable impacts
to natural systems would occur"

In order to consider this factor it must first be broken into two parts:

Part one: "Degradation of ground water quality to the extent that the cost of
treatment is not economically feasible."

Part two: "Degradation of ground water quality to the extent that
unacceptable impacts to natural systems would occur."








As to Part one, using the term "economically feasibile" is enticing. But does it really
provide any help? Is it economically feasible to treat water if there is a market for the
treated water? When is the cost of treatment NOT economically feasible? Regardless of
the cost, is it economically feasible to treat the water so long as there is a market for it?
And conversely, is it not economically feasible when there is no market for the treated
water, regardless of how low the cost might be?

Part one is not qualified enough to be an appropriate factor.

As to Part two, determining when "unacceptable impacts to natural systems would occur"
presents too many subjective questions. What is an "unacceptable" impact to a natural
system? And why should this factor be limited to "natural systems?" Should it not also
be a factor if unacceptable impacts to man-made, or artificial systems would occur?

Part two is too vague and subjective.

Recommended alternative:

Do not include either part of this factor.



Summary Of Recommended Evaluation Factors To Be Included:

Factor: Significant adverse alteration of the rate, magnitude or direction of vertical
or horizontal groundwater flow.

Factor: Long-term trends in upward and landward movement of the
freshwater/saltwater interface.

Factor: Significant, recurring reduction in spatial distribution of chloride
concentrations as follows:

a. Water less than 250 mg/1
(Maximum EPA recommended public drinking water standard)

b. Water less than 1200 mg/l
(Generally the upper limit for agricultural irrigation)

Factor: Significant, recurring or sustained increases in chloride concentrations of
water discharged through springs of magnitude or greater.



SJRSALT


75
tcos ,a.YA--ALT








WRITTEN COMMENTS AND RECOMMENDED ALTERNATIVES
CONCERNING
IMPACTS TO EXISTING LEGAL USER EVALUATION FACTORS



Factor 1 Proposed: "Decline in water level such that a change in pump type is required"

This proposed factor addresses one of the conditions- that might indicate adverse impacts to
existing legal users. There are others, as well.

Florida law protects existing users of water so long as the uses continue to be reasonable-
beneficial uses, and are consistent with the public interest, whatever the current public interest
might be at the time of consideration. Section 373.223, Florida Statutes, provides that in order
to obtain a comsumptive use permit the applicant must establish, among other things, that the
proposed use of water will not interfere with any presently existing legal use of water.

Causing declines in water level to such an extent that a "change in pump type" or "an additional
level of treatment" is required, would unquestionably be considered to be interference with a
present existing user, as contemplated by the statute. Declines in water level might also make
it necessary (1) to add drop pipe, (2) to deepen or replace a well, (3) to lower the pump bowl,
or (4) to reduce withdrawal rates. Merely causing a decline in water or potentiometric level,
alone, is not enough; there must be interference. The new use of water by one, must not
interfere with any presently existing legal use of another. Causing significant increases in
fuel or electrical costs due to having to raise water a greater height within the well might be
considered as interference, but this gets into a "gray" area as to what is significant; and, of
course, the actual cause may be difficult to ascertain.

Recommended alternative:

Decline in water level to such an extent that it interferes with any presently existing legal
use, such as making it necessary to change a pump type, to add a drop pig, to deepen
or replace a well, to lower a pump bowl or to reduce withdrawal rates.




Factor 2 Proposed: "Change in water quality such that an additional level of treatment is
required"

This factor is adequate and appropriate as proposed.





SJREXIST

76
CQO4 11420&01.91c:







STDRO
O6Lg IG-


July 29, 1993


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Ms. Barbara A. Vergara
Department of Ground-Water Programs
and Technical Support
St. Johns River Water Management District
P.O. Box 1429
Palatka, FL 32178-1429

Re: Comments on Water Supply Needs and Sources Assessment Criteria Development

Dear Ms. Vergara:

Enclosed with this letter are comments and suggestions concerning the proposed Salt-Water
Intrusion and Impacts to Existing Legal Users evaluation factors identified in your June 15
correspondence. I feel that the evaluation factors suggested by the District are comprehensive
in scope, but they need substantial refinement to be implementable. I look forward to meeting
with you on September 10 to discuss these issues.

Please contact me if you have any questions or concerns regarding this correspondence.

Sincerely,


Peter S. Huyakorn
President


PSH;sh
Enclosures


1165 Herndon Parkway. Suite 900, Herndon, Virginia 22070 USA
(703) 478-5186 FAX (703) 471-4180


I I








Comments and Suggestions on Salt-Water
Intrusion Evaluation Factors


The term interface, as used herein, indicates the freshwater-saltwater interface as defined by the
250 mg/f chloride concentration isochlor. Or, in other words, the potable/non-potable ground-
water interface.


1) Reversal of vertical and/or horizontal direction of regional ground-water flow

a) I would reword this factor to be more specific: "Change in the
vertical and/or horizontal direction of regional ground-water flow
such that the 250 mg/f isochlor would be expected to move into
regions that are characterized by chloride concentrations which are
less than 250 mg/e." A reversal of flow direction does not have
to occur prior to unwanted impacts; in some cases only a change
in flow direction is required. Also, in certain cases, a change in
the flow direction might improve water quality.

b) The term "regional" needs to be defined explicitly. I think that we
all have a good intuitive feel for what is implied, but it may be
difficult to define "regional changes" for evaluation purposes.
Changes in regional ground-water flow direction may be evaluated
using the potentiometric surface maps produced by the USGS,
which are generally considered "regional" in nature. This
approach, however, may bring scrutiny to the control points used
to construct the maps, and the vicinity of given points to certain
wellfields may become an issue.

c) Changes in regional horizontal ground-water flow directions can
probably be monitored fairly well using data sources such as the
USGS potentiometric surface maps. However, it is very rare that
sufficient data are available to monitor changes in the vertical
direction of ground-water flow between aquifer units. Changes
may be predicted using the District's various simulation models,
but it must be kept in mind that the Lower Floridan aquifer unit is
not rigorously calibrated in any of these models due to a lack of
data. I comment more on data collection efforts at the end of this
summary.

d) My last comment is not critical, and would be addressed in the
suggested restatement of the evaluation factor provided in item (a),
but I should mention that I presume that the District is focusing on
changes in ground-water flow directions in the vicinity of the
freshwater/saltwater interface only. Ground-water flow directions









may be changed or reversed at some distance from the interface
and might consequently have no effect on ground-water quality due
to salt-water intrusion.

2) Vertical or lateral movement of the fresh/salt-water interface

a) Again, this factor should be stated more explicitly. What we want
to assess is interface movement due to increased ground-water
withdrawals. I might note that if the District is considering
movement of the interface prior to the year 2010 only, then little
movement would be expected to occur since once saltwater
intrusion is induced, it takes a long time (at least many tens of
years) to occur. The exception to this is situations where a major
withdrawal occurs in the close vicinity of the interface with a good
hydraulic connection between the withdrawal point and the high-
chloride water body. Such situations are more likely local, rather
than regional, in nature (e.g., the East Cocoa well field).

b) Seasonal fluctuations in the interface location (if it is monitored),
or inherent model uncertainty (if the interface position is
simulated), may tend to obscure the phenomena of interface
movement due to increased ground-water withdrawals. Therefore,
some minimum magnitude of interface movement (rather than
simply "movement") should be considered.

3) Potentiometric surface elevations at or below mean sea level in the Floridan
aquifer

a) This is a good evaluation factor which is closely related to factor
(1). I would note, however, that throughout the central and
southern portions of the District other evaluation factors would
probably "kick in", or indicate potential problems, prior to this
one. This is because in these regions of the District, saltwater in
the Floridan aquifer is relict from earlier geologic periods during
which sea-level was higher than at present. Consequently, the
saltwater wedge present, for example, in eastern Orange County
is not due to saltwater intrusion from the Atlantic Ocean as it
exists today, but was rather emplaced thousands of years ago when
sea level was substantially higher.

4) Change in the spatial distribution of the 250, 1200 and 5000 mg/l chloride
concentrations

a) It seems that change in the 250 mg/f isochlor is essentially the
same as evaluation factor (2) above.









b) In general, this evaluation factor is quite vague. At what depth in
the aquifer system would changes be considered? How much
movement, over what region, constitutes a "change in the spatial
distribution of chloride concentrations"?

c) To assess changes in the spatial distribution, the existing
distribution (both laterally and with depth) should be known with
some confidence. Sufficient data and reports are available such
that the 250 mg/e isochlor is probably known fairly accurately
throughout regions of the District that are most vulnerable to salt-
water intrusion. It is not clear whether or not the 1200 and 5000
mg/e isochlors are known, or could be constructed, in sufficient
detail.

d) In general I like the idea of addressing changes in the various
chloride concentrations based upon possible utilization of the
ground water, but if this evaluation factor is to be used to delineate
Water Resource Problem Areas it needs to be developed in far
greater detail.

5) Change in chloride concentrations of water discharged through springs or through
upward discharge to the surficial aquifer system such that unacceptable impacts
to natural systems would occur

No comment.

6) Degradation of ground water quality to the extent that the cost of treatment is not
economically feasible and/or unacceptable impacts to natural systems would occur

a) Whether the cost of treatment is economically feasible depends
upon the intended use of the water, the size and financial strength
of the utility or industry utilizing the water, and numerous other
factors. I think that the Impacts to Existing Legal Users evaluation
factor 2 may be appropriate here: "Change in water quality such
than an additional level of treatment is required".








General Comments on Saltwater Intrusion Evaluation Factors


1) The salt-water intrusion evaluation factors under consideration can be divided into
two general categories: those that consider a change is ground-water flow
directions or potentiometric head, and those that consider changes in water
quality. I think it is useful to point out some of the strengths and weaknesses of
each category of evaluation factors.

Changes in ground-water flow directions (at least in the horizontal
direction) and potentiometric heads are more easily and accurately
predicted using models, monitored and assessed than are changes
in water quality.

Changes in water quality will probably be significant on a local,
rather than a regional, scale over the next twenty years, and
saltwater intrusion that may occur will more likely be vertical in
nature, rather than lateral.

2) The water quality evaluation factors focus (not surprisingly) on chloride
concentrations. Are there regions of the District where the concentration of other
ions, or total dissolved solids (TDS) should be considered rather than only
chloride? Stated another way, the District may want to at least consider the
possibility that potable drinking water could become non-potable due to unsuitable
concentration of dissolved ions other than chloride.

3) This may be jumping ahead of the game, but I feel strongly that an extensive
water quality monitoring program should be developed and implemented, so that
the existing location of saltwater throughout the Floridan aquifer system in the
vicinity of Water Resource Problem Areas, as well as movement of the saltwater
wedge (vertically and laterally) could be monitored and quantified in key areas.
A monitoring network for a given region should consist of a series of multilevel
wells placed along a transect perpendicular to the saltwater wedge. It is critical
that data from the Lower Floridan (heads and chlorides) as well as the Upper
Floridan, be collected.








Comments and Suggestions on Impacts
to Existing Legal User Evaluation Factors


This is not my particular area of expertise, so I do not have substantial comments about the
proposed evaluation factors. I do, however, have several comments/observations that I will
submit for discussion.

1) Decline in water level such that a change in pump type is required.

a) I assume that the change in pump type refers primarily to
centrifugal pumps do to their limited lift? It is possible that other
types of pumps may also require replacement due to excessive
drawdowns if their lift/capacity is exceeded. Might the District
consider a change in pump type or a required change in pumping
configuration (e.g., lowering of an existing pump to maintain
optimal operation)?

b) Is it reasonable to consider substantial drawdowns that might
require adjacent users to deepen their wells?

c) Increased drawdowns could cause higher operational costs even if
a pump does not require replacement. However, it might be very
difficult to document increased operational costs due to increased
drawdowns. Could an "average" operational water level be
considered?

2) Change in water quality such that an additional level of treatment is required.

No comment.



Proposition: It is appropriate, desirable, and/or possible to consider increased
sinkhole formation potential (due to drawdown) as an impact to
existing legal users?






TAKE m-
States Department of the Interior PM

GEOLOGICAL SURVEY m
WATER RESOURCES DIVISION i
227 N. BRONOUGH STREET, SUITE 3015
TALLAHASSEE, FLORIDA 32301


Barbara A. Vergara, P.G., Director
Department of Ground Water Programs
and Technical Support
St. Johns River Water Management District
Post Office Box 1429
Palatka, Florida 32178-1429


July 28, 1993

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Dear Barbara:

Attached.are my comments on the Needs and Sources Assessment Criteria. I
may have gotten carried away by the freedom of this exercise -- it's rare
that I get an opportunity to do technical writing without going through the
Survey review process. If you think the first two sections are extraneous,
please feel free to delete them.

I enjoyed the experience so far, and look forward to continuing the process.

Best regards,


Sincerely,



Irwin H. Kantrowitz
Area Hydrologist


Enclosure as cited


United










WATER SUPPLY NEEDS AND SOURCES ASSESSMENT CRITERIA, SJWMD
Comments by Irwin H. Kantrowitz


The Concept of "Safe Yield" and Needs and Sources Assessment

In thinking not only of the specific questions posed in the Scope of
Services, but also of the overall exercise the Management District is going
through in its Needs and Sources Assessment Project, I began to view the
entire process in terms of an often (justifiably) maligned term, "safe
yield." The issue of safe yield has long been a controversial one in
ground-water hydrology, and the definition of the term has gone through an
evolution. A good generalized definition is found in Todd's 1959 textbook,
"... the rate at which water can be withdrawn annually without producing an
undesired result." The problem with this, and all other definitions of safe
yield is that the "undesired result" must be defined before the yield can be
quantified. For this reason, the concept of safe yield is not often used in
quantitative ground-water studies. However, the District has the
responsibility of defining the availability of water and protecting the
public from undesired results of water development. This is a valid use of
the concept of safe yield and is exactly what the District is doing in the
Needs and Sources Assessment.

Objective three, "Define thresholds of acceptability of water level and
water quality", is the definition of undesired results. Once these results,
or thresholds, are identified, the amount of water that can be withdrawn on
a sustainable basis (safe yield) without producing these results is
determined; the District has taken a somewhat different approach to this
aspect of the problem -- rather than determine the maximum sustainable
yield, it is attempting to measure the effects of an anticipated yield
(objectives one and two) and then comparing them to the undesired results
(objective four).

The salt water intrusion and legal user evaluation factors address the
definition of "threshold of acceptability" in objective three, or, put in
terms of safe yield, these factors are the undesired results. They state
that at some level of ground-water development, reduced heads and the
movement of the saltwater interface will produce an undesired result. As I
read them, there is the further implication that these results are
undesirable no matter where they occur. This puts some very conservative
restraints on the way the water resources of the District are developed.
This may be the desired approach because it is prudent, possibly legally
defensible, easier to explain or "sell" to the general public and non-
technical managers, and probably easier to manage and coordinate from a
technical standpoint. I realize that a broad look at the way the water
resources of the District are developed, or ways the fresh-water yield may
be maximized, is beyond the scope of your request, yet I feel that a brief
review of alternative development scenarios (containing nothing not already
obvious to you and the District's technical staff) will help put the
evaluation factors into perspective.









Development Scenarios -- the Framework for Analyzing the Evaluation Factors

There are two extreme end members to the ground-water development
spectrum in Florida. One allows for virtually no development so that
conditions remain essentially natural (no drawdown and no movement of the
saltwater interface). The other end member allows for total withdrawal of
all the water in storage, gradually abandoning the aquifers as saltwater
replaces freshwater. A managed version of this end member would allow
saltwater intrusion into most of the aquifer system with water-supply
systems gradually falling back to a freshwater "bubble" maintained under the
central recharge area. A distributed well system in this shrunken remnant
of the ground-water reservoir could continue to supply moderate amounts of
freshwater depending on the size of the managed and protected bubble.

Although planned destruction of most, or even a significant part, of
the groundwater reservoir seems truly extreme, and I am certainly not
recommending it, such a scenario does make maximum use of the freshwater in
storage and allows for a long period of withdrawals that can be far in
excess of natural recharge rates. Consider the case of ground-water
development, or "mining", in arid areas where there is virtually no recharge
and yet where pumping, and consequently, economies have been sustained for
scores of years. Unlike arid areas, Florida receives considerable recharge
so that even after much of the aquifer system has been intruded by
saltwater, the remaining freshwater reservoir will continue to have a
significant perennial yield (although considerably reduced from the yield
during the mining phase of development). Water quality is ignored in this
discussion but is of concern in any development scenario, including the
existing one.

The current stage of ground-water development in the District, and in
all of Florida, is relatively close to the "no development" end of the
spectrum, at least in philosophy (no drawdown, no saltwater intrusion). My
overall sense of the evaluation factors for the Needs and Sources Assessment
is that the District's goal is to prevent conditions in 2010 (and beyond)
from moving very much at all toward the "storage depletion" end member.

Somewhere in the development spectrum there is a reasonably
conservative "storage utilization" scenario that allows for managed
saltwater intrusion and a general lowering of water levels in the ground-
water reservoir so that a new position of hydrodynamic equilibrium is
reached. Under this scenario, all three aquifer systems present in the
District would still contain fresh water although less than they once did;
the volume of intruded saltwater in the aquifers represents the fresh water
removed from storage. The lowered water levels in the ground-water
reservoir will result in an increased rate of recharge and the lower
gradients within the reservoir will result in a decreased rate of natural
discharge. The water withdrawn from storage represents a one-time bonus and
the subsequent sustainable yield from the reservoir can be quite large
depending on its designed size.

As we all recognize, the only sources of water withdrawn from wells are
increased recharge, decreased discharge, and water withdrawn from storage.
Also as we all recognize, the present and 2010 stages of development
certainly represent some degree of storage utilization. The decision facing










the District is how far to go with this development scheme -- for example,
which, if any, coastal wells will be "sacrificed" and what degree, if any,
of streamflow depletion and wetland impact will be permitted. The
evaluation factors developed by the District to assess ground-water
development impacts clearly indicate a decision to minimize the impacts on
current users and on the environment. In other words, the evaluation
factors assume a limited-impact management position on the part of the
District. Given the well-established localized pattern of water-supply
development in Florida, the rural nature of much of the District, the
importance of environmental concerns, and the overall direction set by the
Legislature, this may well be the only management position possible. My
analysis of the evaluation factors will, therefore, be based on this
limited-impact, conservation-of-storage approach to water management.
Obviously a more "aggressive" approach would require a different and far
more complex set of evaluation factors.

Salt Water Intrusion Evaluation Factors

Factor one (reversal of flow) is a valid generalized criteria. The
only problem is that it is written in such a way that a shallow reversal to
induce recharge from a stream, for example, would be considered a negative
impact. The reference to "regional" flow may cover this but perhaps the
phrase "such that the direction of flow is from salt water toward fresh
water" can be added.

Factor two (movement of the interface) theoretically occurs every time
ground water is withdrawn from a well. Consider that popular hydrologic
device, the isotropic circular island. As soon as fresh water is
artificially withdrawn, the natural discharge is decreased and the saltwater
interface moves inland and upward to a new position in balance with the
reduced recharge. This is inevitable and does not require a reversal of
gradient (factor one), only a decrease in gradient. The factor should be
stated in terms of where the interface will stabilize, not whether it moves
or not. Perhaps this factor should be omitted, but if doing so leaves only
factor one, it should be noted that significant saltwater intrusion can
occur without reversing the gradient and it appears to be the District's
intent not to let that happen.

If we consider only horizontal saltwater intrusion, factor three
(potentiometric surface at or below sea level) may be too restrictive. It
would be possible to lower heads at an inland location and still maintain a
positive seaward gradient at the interface (for example, the Volusia County
high which is seaward of low heads in the St. Johns River valley). The
possibility of upcoming of saltwater, however, makes this factor
theoretically supportable. All in all, it may be the best of the factors.
There is some overlap with factor one, that is, a reversal of flow direction
to induce saltwater movement will generally require a fresh-water head below
sea level. I'm not clear why this factor is restricted to the Floridan
aquifer. Again it should be noted that saltwater intrusion can occur even
if water levels are not lowered below sea level.

Factor four (movement of the isochlors) suffers from the same
difficulty as factor two; that is, movement of the isochlors is inevitably












linked with pumpage and any new withdrawal can be argued to induce
additional movement.

Factor five (changes in chloride concentration of natural discharge) is
again an inevitable consequence of pumpage except that the qualifying
statement regarding unacceptable impacts may make it defensible. Do the
unacceptable impacts need to be more tightly defined? Do you need to
consider that decreases in pumpage may increase fresh-water discharge and
have a negative impact on what we have come to regard as a "natural" system,
for example saltwater fish that presently occupy an estuary reach made salty
by ground water withdrawals?

With regard to "natural systems", factor six (degradation of ground
water quality) is similar to factor five. Because it also includes non-
natural uses of ground water, it may be preferable to five. My questions
concerning objective five also apply here except that the term "degradation"
may eliminate my concern over water becoming more fresh. An additional
concern with factor six is the subjectivity of what constitutes economical
treatment. Perhaps chloride concentrations for various uses, or some
indexed cost per thousand gallons should be used.

Impacts to Existing Legal User Evaluation Factors

Both factors make practical sense at first reading. To avoid
subjectivity or capriciousness in their application, it might be best to
relate these to mappable areas with given depths to water (factor one) and
given required treatment for various uses (factor two). For example, areas
where centrifugal pumps can presently be used could be delineated for each
aquifer; the impact criteria would be an increase in required lift of more
than 25 feet. A water quality example would be areas where ground water
presently requires only sanitary treatment; the impact criteria would be an
increase of chloride to more than 250 mg/l.

Surface Water Bodies

This is outside the scope of your request but I thought it was worth
commenting on. As we all know, ground water and surface water cannot be
treated as separate resources. The District will need to consider the
effect of a given long-term rate of ground-water withdrawal (for example,
the 2010 pumpage) on the position of the water table. The Needs and Sources
document does this to some extent with regard to the vegetation criteria but
it is not clear if this is also to be done with regard to the surface water
criteria. The consideration of lower water-table levels will raise the
complexity of the surface-water analysis but this cannot be ignored. A
lower water table will not only have environmental effects, but it will also
affect the ability of streams and lakes to act as sources of water supply.
It can be argued that, environmental concerns aside, the most efficient way
to develop the total water resources is to uniformly lower the water table
to totally dry up the streams and lakes. This will increase recharge and
decrease natural discharge and make this water available for development.


~
__







/ANCE W. KIDDER


July 30, 1993 L---



Barbara Vergara, P.G.
Director, Department of Ground
Water Programs & Technical Support
St. Johns River Water Management District
PO Box 1429
Palatka, Fl 32178-1429

Dear Barbara:

Please find enclosed herewith my written analysis for alternatives
for the salt water intrusion and existing legal user impacts
portion of the Water Supply Needs and Sources Assessment. The
format I have used is to pose the questions asked, answer them and
then make recommendations.

Also please find a detailed statement of the time spent and
activity done thus far in furtherance of my commitment to the
District. I recently became a sole practitioner. Is it possible
for the Board to authorize me payment at the August meeting for the
work done thus far? If so it would be of immense value to me.

Sincerely,



Vance W. Kidder

VWK/ss

enclosures


















ANALYSIS OF SALT WATER INTRUSION AND
IMPACT TO EXISTING LEGAL USER EVALUATION FACTORS


QUESTIONS:

A. Is the description of conditions which constitute unacceptable
salt water intrusion and impacts to existing legal users
reasonable, practical and legally supportable?

B. Are the methods and approaches proposed for measurement of the
magnitudes of salt water intrusion and impacts to existing legal
users reasonable, practical and legally supportable?

C. What are alternatives to the potential evaluation factors
which are more reasonable, practical and legally supportable?


ANSWER:

The beginning step in my analysis is to survey relevant statutory,
rule and case law. The statutory provisions I reviewed are
Sections 373.016, 373.036-.042, 373.1961, 373.219-.226, Fla. Stat.
The rule provisions, including Handbook provisions, I reviewed are
Part III, IV and V, Chapter 17-40, Fla. Admin. Code, Section 40C-
2.301, Fla. Admin. Code, Section 40C-23.001, Fla. Admin. Code, Part
II of the Applicants Handbook and Chapter 17-520, Fla. Admin. Code.
The cases I reviewed are Tampa Waterworks Co v Cline,. 20 So. 780
(Fla. 1891), Carson v Florida Power Co., 76 So. 535 (Fla. 1917),
Kock v Wick, 87 So. 2d 47 (Fla. 1956), La Bruzzo v Atlantic
Dredging & Construction, 54 So. 2d 673 (Fla. 1951), City of Enid v
Crow, 316 P.2d 834 (Okla. 1957), Jones v Oz -Ark Val Poultry Co,
306 S.W. 2d 111 (Ark. 1957) and Taylor v Tampa Coal Co, 46 So.2d
392 (Fla. 1950). I also reviewed the draft Water Supply Needs and
sources Assessment that was presented to me.

The purpose of the beginning step is to decide whether the
description of conditions and approaches and method of measurement
of the proposed evaluation factors contravene existing law. Of
course to not contravene existing law does not necessarily mean
that the proposed evaluation factors are reasonable or practical or
the most reasonable or practical within existing law. Moreover to
be the most practical or reasonable within existing law does not
mean the proposed evaluation factors are THE most reasonable or
practical. Thus the second step of the analysis is to look in to
reasonableness and practicality.
















Legality


The Water Supply Needs and Sources Assessment is a document
prepared pursuant to and to satisfy Section 17-40.501, Fla. Admin.
Code, District Water Management Plans. Consequently the document
has to identify specific geographical areas that have water
resource problems which are critical now or which are anticipated
to become critical within the next 20 years and it has to specify
a course of remedial or preventative action for critical problems.
Section 17-40.501, Fla. Admin. Code, implements Sections 189.4156,
373.036(4), 373.0391(2)(e) and 403.064, Fla. Stat. The orientation
of these statutory provisions, Section 403.064, Fla. Stat.,
somewhat excepted, is towards planning. Indeed the Needs and
Sources document is part of the District's water management plan.

The proposed impact criteria are included in the criteria used for
consumptive use permitting. See Section 40C-2.301, Fla. Admin.
Code. Salt water intrusion is included as a consideration related
to whether a use is reasonable-beneficial and a use that would
cause "significant" salt water intrusion or "aggravate existing"
salt water intrusion cannot be a reasonable-beneficial one.
Section 40C-2.301(4), Fla. Admin. Code.; A.H. 10.3.(h). A.H. 9.4.2
embellishes the criteria. Interference with existing legal users
is a statutory criteria which is merely reiterated in Section 40C-
2.301, Fla. Admin. Code., but is embellished upon in A.H. 9.2 and
9.4.4.

A.H. 9.4.2. defines "significant saline water intrusion" to mean
"saline water encroachment which detrimentally affects the
applicant or other existing legal users of water, or is otherwise
detrimental to the public interest". Thereafter is set out how
saline water encroachment is to be determined to wit:

a. Movement of a particular saline water interface to a
greater distance inland or towards a wellfield than has
historically occurred as a consequence of seasonal
fluctuations or drought. For purposes of this document, a
saline water interface is defined as a zone of dispersion
between two geochemical types of ground water or a zone of
change between areas of ground water with significantly
different chloride concentrations.

b. A significant increase from background levels in chloride
concentrations at the base of the aquifer or producing zone
within the area of influence of the well field. Background
levels are the chloride concentrations that existed before
withdrawals commenced.

















c. A significant detrimental change in the geochemistry of
the ground water at the base of the aquifer or producing zone
within the area of influence of. the wellfield. An example of
such a change in geochemistry is where a newly constructed
well may yield a bicarbonate type water initially, but after
withdrawals commence the well or nearby wells yield a sodium
chloride type water. This change is an indication that
intrusion of saline water has taken place during the
withdrawal of water.

A.H. 9.2.2 defines "interference with a legal use of water "to
mean" a decrease in the withdrawal capability of any individual
withdrawal facility of a legal use of water which was existing at
the time of the application for the initial permit such that the
existing user experiences economic, health or other type hardship".
A.H. 9.4.4. sets out how interference is to be determined, to wit:

It is presumed that an interference occurs when the withdrawal
capability of any individual withdrawal facility of a
presently existing legal use of water experiences a 10% or
greater reduction in withdrawal capability or when the
existing user experiences economic, health, or other type of
hardship as a result of the new use.

The percentage reduction in withdrawal capability is
calculated in the following way:


(withdrawal capability prior to
impact (gpm) withdrawal
% Reduction = capability after impact (gpm) X 100
withdrawal capability prior
to impact


If presently existing legal uses rely on wells fitted with
centrifugal pumps, then the evaluation of interference will be
made assuming that the length of the drop pipe is equal to the
lift capability of the centrifugal pump affixed to the well.

If presently existing legal uses rely on wells fitted with
non-centrifugal pumps, or on centrifugal pumps other than
described in the aforementioned cases, the District will
evaluate adverse impact on a case by case basis.

The Handbook also sets out how an interference will be dealt with
vis-a-vis a pending applications for permit to wit:




















If the requested allocation will not cause an interference
with legal uses of water which existed at the time of permit
application, and it also meets other evaluation criteria, then
this will be the amount allocated. If the requested volume
causes an interference with legal uses of water that existed
at the time of the permit application staff will then
recommend this amount as a maximum allocation unless the
interference is eliminated by the applicant.

The District proposes as evaluation factors for the two impact
criteria, the following:



Salt Water Intrusion
Evaluation Factors

1. Reversal of vertical and/or horizontal directions of regional
ground water flow

2. Vertical or lateral movement of the fresh/saltwater interface

3. Potentiometric surface elevations at or below mean sea level
in the Floridan aquifer

4. Change in spatial distribution of chloride concentrations as
follows:

a. Water less than 250 mg/1
b. Water less than 1200 mg/1
c. Water less than 5000 mg/1
Note: These ranges are based on 250 mg/1 as the EPA
recommended public drinking water standard, 1200
mg/1 as the upper limit for agricultural irrigation
and 5000 mg/1 as the upper limit for cost-effective
treatment of water for public supply using reverse
osmosis.

5. Change in chloride concentrations of water discharged through
springs or through upward discharge to the surficial aquifer
system such that unacceptable impacts to natural systems would
occur
















6. Degradation of ground water quality to the extent that the
cost of treatment is not economically feasible and/or
unacceptable impacts to natural systems would occur


Impacts to Existing Legal User Evaluation Factors

1. Decline in water level such that a change in pump type is
required

2. Change in water quality such that an additional level of
treatment is required

The questions posed have an ambiguity in them. The questions can
be read to have "unacceptable" modify both "salt water intrusion"
and "impacts to existing legal users" or merely "salt water
intrusion". In that the District's rules only attach a
significant/insignificant distinguishment to salt water intrusion,
the question will be answered from the vantage of any interference
with existing legal uses is an unacceptable impact.

The proposed salt water intrusion evaluation factors include six
items. None of these are, as written, in conflict with the
statute, rules or the A.H. However, the A.H. seems to be more
focused as to what is to be measured and how. Similarly the
proposed impacts to existing legal user evaluation factors are not
in conflict with the statute, rule or A.H. but, again, the A.H.
seems to be more focused as to what is to be measured and how.



Reasonability and Practicality


The purpose of the Needs and Sources document is, as was stated
previously, to identify resource problem areas that are or likely
will be critical and specify remedial or corrective actions.
Stated another way the District is to identify existing and likely
water resource problem areas and propose solutions for the worst
problem areas. The task then is to evaluate and critique the
proposed evaluation factors as to how reasonable and practical they
are in identifying water resource problem areas and identifying
those that are the worst problem areas.

Section 17-40.501 Fla. Admin. Code, uses the words "water resource
problems". The draft Needs and Sources document employs the words
"water resource impacts" as the common noun for the various
consequences that water withdrawals can have to cause water
















resource problems. Indeed water withdrawals can adversely effect
vegetation, ground water quality, legal users and surface water
bodies but does each as proposed by the District denote a water
resource problem area.

It seems to me that interference with an existing legal user in the
form of a change in pump type does not denote a water resource
problem area, let alone a critical one. Such interference are a
problem for the owner whose pump needs changing but that is not a
resource problem necessarily, nor an areal problem, nor a critical
one. Thus were the District to view change in pump type as an
evaluation factor it would seem to me that change over an area
would be more relevant. Pump change over an area would be due to
withdrawals exceeding recharge/replenishment so that there was
areal lowering of the ground water or surface water. It may be
that the statement presented to the consultants is too cryptic. In
any event declining water levels do portend for problem areas but
I am not sure a pump change is the needed evaluation factor.

The other proposal for impacts to existing legal users is a change
in water quality that causes a need for additional treatment. Of
course changes in water quality are also what salt water intrusion
seeks to address. Again it may be that the statement presented is
too cryptic. The need for an additional level of treatment for a
user may not denote a water resource problem, let alone a critical
one. (See the appended Agricultural Significance chart as
illustrating how the need for additional treatment may not signify
a problem area.) The suggested statement does not seem to equate
*with an areal situation sufficient to be called a water resource
problem.

The Impacts to Existing Legal User evaluation factors do not seem
to adequately address withdrawals from surface water. The normal
adjustment on a surface pump due to a decline in water level does
not take the form of a change in pump type; usually merely the
intake structure is extended or modified. Also is the additional
level of treatment component intended to address contaminants other
than salt water intrusion. If so is there some way to deal with
movement of contaminants by observations of ground water flow on an
areal basis.

The intrusion evaluation factors variously address a change in
regional groundwater flow, movement of an interface, below sea
level potentiometric surfaces, changes in chloride distributions,
change in chlorides that adversely impact natural systems or
springs and changes that make treatment uneconomical. All of these
seem to me to be matters that warrant concern. However I believe
all of these need to be developed to the point where persons of
















reasonable mind could not differ. I also believe that as these
matters are developed some of them may be subdivided or combined.
Lastly, the utility of these evaluation factors depends on how they
are employed.

The District must intend to take population projections, run them
through the groundwater models it has and see what areas, if any,
exhibit any of these evaluation factors. However I am not sure
where these evaluation factors leave the district.

We know that withdrawals can have effects on surface features such
as vegetation or water in water bodies due to deprivation of the
water to areas normally occupied by water. The description of the
vegetative criteria seems to address a response factor between
water and vegetation. The District has done studies of this nature
concerning surface water and vegetation. Similarly the District
has done studies of and projections for water quality in surface
waters based on projected conditions. It seems to me as evidenced
by the draft Needs and Sources document that similar studies and
projections have been commenced by the District for ground water
withdrawals. It may be that the proposed salt water intrusion
evaluation factors are to be employed to define resource problem
areas. If so there is no obvious means to define critical problem
areas. Conversely if the evaluation factors are employed to define
critical problem areas are they too insensitive.

It seems to me that the call to identify water resource problem
areas is to identify where sizeable harm to the water resource is
likely to occur if growth, as planned, occurs. Section 373.219(1),
Fla. Stat., requires imposition of permit conditions to assure a
use is not harmful to the water resources of an area. Similarly
Section 373.0391 (2)(g), Fla. Stat., addresses prevention of harm
to water resources (and ecosystems) through information reflecting
minimum water levels for aquifers. The latter statutory provision
is not one cited as a law that Section 17-40.501, Fla. Admin. Code,
implements, neverless it, more so than Section 373.0391 (2)(e),
Fla. Admin. Code, which the rule implements, seems to me to be more
in line with what the proposed evaluation factors would indicate
the District is attempting to do.

District Water Management Plans, which the Needs and Sources
document would be a part of, are not regulatory in nature but
advisory in nature. The plans, as the headings and texts of
Sections 373.036, 373.0391, and 189.4156, Fla. Stat. indicate, are
advisory to local government. Thus, unless the District through
consumptive use permitting does something to avoid the ends that
projections based on comp plans portend, local governments will
















have to amend their comp plans to avoid the projected ends. I
defer to those consultants who are technically oriented to opine
whether the models the District has can be employed with population
as it appear the District must intend. However it seems to me that
should the projections be able to denote the matters embodied in
the evaluation factors, the evaluation factors need to be word-
smithed, fine-tuned and refined. Lastly the matter of transposing
from problem area to critical problem also needs to be addressed.


RECOMMENDATION

The process the District seems to have set out should facilitate
refinement, fine-tuning and word-smithing. If my assumption of how
the evaluation factors will be employed is correct and the
projections will denote the matters the evaluation factors set out,
proceed to refine, fine-tune and word-smith. If not its back to
the drawing board.

































AGRICULTURAL SIGNIFICANCE


o 2 0
50
100 -

180 300

250 -~- 410
300 -





550 900
600 -


730- .'- 1200



900 1500




1100-- 1800

1200- 2000


Injures some orchids
Recommended lirmi for public supplies


Kills aolFas, causes injury to some tender plants, vegetc'les, flowers,
and citrus 'fiioge


Damages a number of succulent p!onts



Domoges bohiogrnss, sweetgum, tibouciina, end mcny foiroee plants.




Injures muny woody plonts including citrus (loot areo)

Nol recommended for plant use except St. Augustine grass.


- -













SJRWMD

DATE

6/18


6/21

6/22

6/29


7/09

7/14

7/15,

7/21

7/22

7/23

7/26

7/27

7/28

7/29

7/30


MATTER/FILE NO.

Call B. Vergara's office to verify draft "Needs" report
is yet to be sent

Review of draft "Needs" report

Review of draft "Needs" report

Collect statutes, rules, legal opinions, cases, treatises
on water use standards

Formulate method of analysis/approach to task

Review of authorities regarding intrusion/interference

Review of authorities regarding intrusion/interference

Review of authorities regarding intrusion/interference"

Review of authorities regarding intrusion/interference

Review of authorities regarding intrusion/interference

Begin memorandum/analysis

Continue memorandum/analysis

Continue memorandum/analysis

Continue memorandum/analysis

Finish memorandum/analysis
Total


HRS 10THS

2


3

5


1 5

1 0

1 1

1 2

1 5

2 3

3 0.

5 1

2 7

2 4

3 6

2 1
28.5






Kubal-Furr & Associates
Environmental Consultants


P.O. Box 273210
Tampa, FL 33688-3210
813/931-7730
FAX/931-8039

28 July 1993



Ms. Barbara A. Vergara, P.G., Director
Department of Ground Water Programs
and Technical Support
St. Johns River Water Management District
Post Office Box 1429
Palatka, FL 32178-1429


P.O. Box 846
Greenville, SC 29602
803/370-0470
FAX/370-9798



j n 3 1993
L IAlLBIflM I


_i A I MM -.- I


Re: Water Supply Needs and Sources Assessment Criteria Development

Dear Barbara:

I have reviewed the information you recently provided on evaluation factors for salt water
intrusion and existing legal user impacts in regards to our "Needs and Sources Assessment"
project. I have also reviewed the District's October 1992 draft assessment report which provided
helpful background information on project objectives.

I think the easiest way to present my suggestions would be to offer general comments on the
project and the District's draft report, and then to provide more specific comments and
recommendations on the potential evaluation factors.

General Comments:

The District has done a very good job of summarizing the current status of ground- and surface
water resources and the projects which are underway to evaluate the potential impacts of future
uses of this water. If things are taken at face value, it appears that only relatively minor and
geographically specific impacts are predicted during the planning period (i.e. 1990-2010).

Although the District is consistent in applying their assumptions in the report, it appears in
some instances that certain aspects of the document need further consideration. For example:

The District admits that a substantial disparity exists between projected water use and
population growth estimates, although it doesn't identify in which direction. Some of the
recent studies I have seen indicate that the movement of people into the State is running
about even with the people moving out. If the net flux of people remains fairly constant, it
would obviate the need for a lot of this planning wouldn't it? The population estimates are
the basis for the water use projections; if these numbers are unreliable, what does that say
about the conclusions derived from the assessment report?










Ms. Barbara A. Vergara


It still seems a safe bet that specific areas will grow and that problem areas will develop,
especially in Orlando. However, the inevitability of water reuse (specifically grey water for
irrigation and lawn sprinkling), conservation, etc. could dramatically affect the final
demand numbers and predicted impacts. Time spent refining estimates of the various water
budget components (e.g. potential reuse, conservation, evaporative losses, etc.) would be
well spent and seem at least as important as the efforts now being spent on ground-water
modeling.

Regarding the modeling efforts the District points out the likely underestimates in Floridan
aquifer drawdowns using these models because of assumptions about constant water table
elevations. To compensate for this, the District has to go through various transformations
of the data to arrive at more realistic estimates of the drawdown. I assume this is a
legitimate technique but I think the admitted reliance on "reasonably average climatic
conditions" to prevail in the future is unrealistic.

The story is told about the statistician who with one hand on a hot burner and one hand in
the freezer indicated that on the average he felt comfortable. The water management districts
were not formed to deal in averages, hence the original South Florida Flood Control
District. As it applies to the current project, I would think the District has to deal with the
worst-case scenario (i.e. persistent drought conditions) and has to be firm with the various
municipalities when it comes to instituting water conservation and reuse measures.

In the section on Guiding Principles, the District assumes an oversight and review role with
respect to the major water users. This is politically correct I would guess but it would seem
like one way to realistically deal with needs and sources problems in the future is for the
District to get into the water supply business. Are water supply authorities within the
District out of the question?


Salt Water Intrusion Factors:

When considering salt water intrusion, a differentiation needs to be made with respect to
connate intrusion versus modern, lateral salt water intrusion. This distinction is important
because it may complicate the evaluation factors somewhat.

For example, the U.S. Geological Survey conducted an off-shore drilling project of the
Floridan aquifer about 30 years ago off the coast near Jacksonville. At a distance of 25
miles off-shore, water in the Floridan was still fresh, and at 60 miles it was just turning
brackish. There is a tremendous amount of fresh water discharging along the margins of
the Florida peninsula and in the northeast Florida area, the intrusion problems that were
experienced at Fernandina some years ago were the result of connate water moving upward
and not modern, lateral intrusion.

Since ITT Rayonier and Container Corporation stopped completing their wells below the
low permeability, dolomitized zone at 1100-1200 feet, the intrusion problem has been
stopped or diminished-even though they are lowering the potentiometric surface as much
as 125 feet, or more, below mean sea level. Therefore, pumping below mean sea level is
not necessarily as bad as it intuitively seems, and evaluation factor #3 needs to be thought
about a little more before a blanket prohibition is issued.



Kubal-Furr & Associates


_ _I __ ;.. ~.~_..I


28 July 1993








Ms. Barbara A. Vergara 3 28 July 1993


SRegarding evaluation factor #1, reversal of the natural gradients may actually be beneficial,
especially in an area in which the aquifer is saturated and is rejecting recharge. What should
be of more concern in the evaluation factors are those instances where actual dewatering of
the formation may be occurring. In an artesian aquifer, the supply is derived from
expansion of the water and compression of the grain skeleton and not from storage and
dewatering of the formation-unless the water level is being drawn down below the base
of upper confining unit. From that standpoint, why is the "Big Red Hole" in the phosphate
mining area of so much concern? These areas will be mined out in a matter of perhaps ten
to twenty years and once the pumps are shut off, the water levels in this area would be
expected to recover. Mining of water and dewatering of the aquifer is not occurring here,
rather, a few tens of feet of head are being knocked off the potentiometric surface in the
interim while mining takes place.

SWater quality monitoring to observe long term trends in chloride concentrations (and other
basic water quality parameters) seems like a good idea. What needs to be explored is at
what point along the degradation curve the District stops issuing permits? Can the flow
models be coupled with the water quality changes so we will know that the next applicant
in the door will have to be the last one considered? Also, wouldn't the lowest threshold
value (i.e. 250 mg/L) have to be the only standard considered? An industry or agricultural
user that comes in to a public water supply area which has borderline quality cannot be
expected to obtain a consumptive use permit even though it could use water which is totally
unacceptable for potable use, isn't that correct?

SThe evaluation factors related to natural systems are very difficult to comprehend and
assess because ground-water influences on natural systems cannot be considered in
isolation. Because these natural systems generally are at or near the surface of the earth,
they are affected not only by things such as spring discharge, water-table elevation, etc.,
they also are affected by stream flows, rainfall patterns, tidal influences and changes in land
use. As long as bulldozers continue to roam around and change the Florida landscape, most
of these subtle water quality changes on natural systems are no more than a technical
curiosity. As a practical matter, when developers pave over the black circles on the
predicted water-table change maps should I be concerned that the water levels under the
parking lot used to be 10 or 20-ft higher?


Impacts To Existing Legal Users:

*In the normal course of events, the declines in water levels and changes in water quality are
usually very subtle and only become an issue when their cumulative effect exceeds some
threshold value (e.g when chlorides exceed 250 mg/L or water levels drop below the pump
bowls). It's easy to quantify the impacts in the fern growing area during frost and freeze
protection periods, and this short-term situation could be solved by changing pumps,
deepening wells, constructing elevated storage facilities, etc. (although your house being
swallowed by a sinkhole could become a more important issue than being out of water
temporarily).

But, in these examples, exactly who pays? Each new withdrawal lowers the water levels an
incremental amount and it costs you a few pennies more per month to lift water. As
additional withdrawals are permitted, a point comes where some of the shallower wells
break suction or may no longer be able to pump. Obviously the last permitted that caused


Kubal-Furr & Associates
101








Ms. Barbara A. Vergara


the level to exceed this lower threshold shouldn't bear the entire cost burden, but, what is
the District to do-set up a trust fund from permit fees to retrofit problem wells on an as
needed basis? A similar set of circumstances develop on the quality side of this issue as
well but is installing an individual treatment systems as practical as deepening a well or
installing a new pump?

Closing Comments:

I've presented more questions than answers in.this initial assessment but I think these issues,
and the many more that others on the committee are likely to pose, will provide a good point of
departure for our first meeting. I look forward to reviewing these responses and I'm confident
we'll have a very productive session in September.


Sincerely,


Jerry Kubal


Kubal-Furr & Associates
102


28 July 1993










Engineers
Planners
WIiSIl Economists
Scientists F ece'

July 30, 1993

Ms. Barbara A. Vergara, P.G., Director
Dept of Ground Water Programs and
Technical Support
St. Johns River Water Management District
PO Box 1429, Palatka, Florida 32178-1429

Re: Water Supply Needs and Sources Assessment Criteria

Dear Ms. Vergara:

I am pleased to provide the following comments relative to the evaluation factors proposed by
the District to establish threshold levels for regulatory response to "salt water intrusion" and
for "impacts to existing legal users."

I have read the "Draft Water Supply Needs and Sources Assessment," dated October 1992, and
also rely for my comments upon engineering and hydrogeologic experience gained at various
locations within the SJRWMD area during the past 23 years, as well as other locations in Florida
and elsewhere. My response is in the format suggested in the Scope of Services, Exhibit A to
the Agreement for Professional Services. Copies of the proposed evaluation factors are attached
for reference purposes.

Is the description of conditions which constitutes unacceptable salt water intrusion and
impacts to existing legal users reasonable, practical and legally supportable?

Salt Water Intrusion

1. "Reversal of vertical and/or horizontal directions of regional groundwater flow" is not quite
adequate as an evaluation factor as it fails to define the term "regional." Any groundwater
production will reverse flow direction in the vicinity of a well or wellfield. The important issue
relative to salt water intrusion is whether flow direction is reversed in the vicinity of the
interface. Where the concern is upwelling of brackish water from below, the proven existence
and competence of a lower confining layer beneath a production zone can effectively prevent
upwelling. Where the concern is lateral movement, separation of the wellfield from the interface
by a sufficient distance, or by a salinity barrier, can ensure that a sufficient positive gradient is
maintained at the interface, thereby controlling intrusion. Hence I suggest that the proposed
evaluation factor be amended to include the additional phrase "in the immediate vicinity of the
interface."



CH2M HILL Gainesville Office 7201 N.W. I Ith PIGW, Gainesville. FL 32605-3158 904.331.2442
PO. Box 147009. Gainesville. FL 32614-7009 FAX. 904.331.5320










2. "Vertical or lateral movement of the salt water interface" is probably the most important
of the suggested evaluation factors, however the wording is incomplete. Whether or not the
flow direction is reversed in the vicinity of the interface (evaluation factor 1), the interface will
move inland in response to a reduced gradient. The rate at which it moves depends upon aquifer
hydraulic characteristics and the change in gradient. While the direction of interface movement
is quite important, the rate at which it moves is just as important. Inland movement at the rate
of one foot per year is not as severe a problem as inland movement at the rate of 300 ft per
year. Consequently the evaluation factor wording should incorporate some reference to rate of
movement.

In many situations insufficient water quality data is available from properly designed monitor
wells to fully document the rate of interface movement inland. However historic anecdotal
evidence may point to a coastal band within which formerly fresh wells have been abandoned
due to intrusion, or inland wells have been abandoned due to long-term upwelling from below.
This can be used to demonstrate that interface movement has occurred historically and maybe
even to approximate a rate. Consequently it may be advisable to incorporate the broad concept
of reasonable historic evidence for interface movement. Otherwise regulatory action could only
be based upon situations where hard data is available. This would require some checks and
balances so that regulatory actions with substantial economic impact are based upon facts
combined with prudent judgement of water resource response.

Where I have had the opportunity to look closely at interface movement in Florida, it seems that
the interface sometimes moves around quite a lot from month to month, both vertically and
laterally, in response to climatalogical and man-made factors, and measurement errors. Hence
it is advisable to introduce the concept of a trend, as measured over a period of at least five
years at a similar season of the year. While salt water intrusion is a serious water management
concern, the rate tends to be slow. In most of the areas identified as causes for concern by
2010, requiring at least five years of data to establish a reasonable basis for action would not
be a significant harm to the aquifer system or environment. Much of the data probably already
is being collected for these areas.

Combining these different ideas, I suggest that this important evaluation factor be reworded as
follows: "Vertical or lateral movement of the salt water interface as measured by: a lateral rate
of at least 100 feet per year for a period of five years or more; vertical interface movement as
measured by chloride concentration increases of at least 10 mg/1 per year for five or more years
in monitoring or production wells; or as estimated based upon reasonable historic evidence such
as abandonment of irrigation wells due to deterioration in water quality."

3. "Potentiometric surface elevations at or below mean sea level in the Floridan aquifer."
This is an easy, but not very enlightened management approach. It is more of a "first cut"
evaluation factor that may prove misleading when applied rigorously at specific sites. At some
locations it is vitally important to maintain elevations above sea level such as 2 to 5 ft or more,
in order to maintain an adequate barrier to inland movement of salt water at the base of a
shallow coastal unconfined or semi-confined aquifer. At other locations, potentiometric levels
below mean sea level can be maintained without any threat to the aquifer system or environment.
This would be due to adequate vertical (lower) confinement, horizontal distance from the coast,









or the existence of a natural or artificial recharge boundary that maintains a potentiometric
mound between the site and the coast. I would be inclined to delete this evaluation factor from
the list, leaning more heavily on the other factors.

4. I am not sure what a "change in spatial distribution of chloride concentrations" really
means. Clear, definitive data regarding interface movement is sometimes expensive and time
consuming to obtain. In the absence of this data it is perhaps useful to include as a backup
evaluation factor the possibility that steadily increasing chloride concentrations over a period of
five or more years in many production or monitor wells throughout a specific area of interest
would be a valid indicator of a problem.
A suggested rewording of this factor could be "a trend of increase in chloride concentrations of
production or monitor wells over a period of five or more years within an area surrounding a
well or wellfield that is defined by a drawdown of three feet or more." Whether three feet is the
right number or not is a subject for discussion, and probably depends upon wellfield location
relative to the interface.

5. I would delete this proposed evaluation factor. Excessive ground water withdrawals are
more likely to reduce flow from, or dry up, springs than to cause them to produce higher
chloride water. The change in spring flow would then cause the impact to natural systems.
While this is undesireable, it has little to do with salt water intrusion.

Upward discharge to surficial aquifer systems may be increased by heavy pumping from these
systems where there is inadequate lower confinement. However, the impact to natural systems
would probably be caused by the pumping and associated lowering of the water table. It is less
likely to be caused by the upwelling of poor quality water from below unless the water is used
for local irrigation. If the chloride concentration is high enough to affect natural systems it is
probably unsuitable for irrigation in the first place. Adverse impacts to natural systems caused
by water table lowering are probably already covered in the District's regulations, making
adverse impacts due to upwelling of poor quality water to be of lesser marginal value. I would
suggest deleting this factor and relying upon reworded No. 6 below.

6. The cost of water is rarely a significant motivating factor, at least within the range of
costs currently applicable in Florida. From conventional treatment at perhaps $1 to $2 per
thousand gallons to salt water desalination at about $7 per thousand gallons, people will pay
what it takes. Severe degradation of groundwater quality due to increasing chloride
concentrations is a sure sign of salt water intrusion and should be avoided on its own merit,
unrelated to treatment costs. This is already covered under 4. above and therefore does not need
to be covered twice. I would re-phrase No. 6 as follows: "Unacceptable impacts to natural
systems caused by a trend of increasing chloride concentrations."

Impacts to Existing Legal Users

1. "Decline in water level such that a change in pump type is required," is good in that it
avoids the issue of incremental increase in pumping costs caused by an applicant's lowering of
potentiometric levels. Every time I have had to work this out, it amounts to a trivial amount
of money that could arguably be disregarded for current regulatory purposes. However the









wording is deficient in that it does not address the issue of impact upon someone whose pump
needs a deeper setting as a result of a permitted withdrawal that lowers the water level around
the pump bowls. The cost of this, in my opinion, should be borne by the new user. I would
re-word this as "Decline in water level such that a change in pump type, or a deeper pump
setting, is required by an existing user due to the new use."

2. I would clarify the wording as follows: "Change in water quality such that additional
treatment is required due to the new use." Additional treatment by water utilities is being
required by EPA for many reasons in the next few years, so it is important that the evaluation
factor differentiate between treatment requirements due to the new use and those due to external
reasons.

Are the methods and approaches proposed for measurement of the magnitudes of salt water
intrusion and impacts to existing legal users reasonable, practical and legally supportable?

This level of detail has not been proposed by the District, but is needed in order to provide
guidance as to what is significant and what is not. Otherwise there will tend to be an over-
reaction to minor changes in interface location or existing user impacts that may reduce
credibility and therefore weaken the District's ability to respond to significant changes when and
where they may occur.

I would rank the problem areas for potential salt water intrusion and focus on establishing a
monitoring network in the more serious areas first. Modelling should also focus on these more
serious areas. More rigorous methods and approaches (evaluation factors 1 and 2) would be
applied in these areas first, relying upon simpler methods (evaluation factors 3 and possibly 6)
in other areas.

Evaluation factor 1 is sufficiently definitive, as reworded above, assuming that an adequate
monitor well transect is available to confirm gradient reversal near the interface. Regarding
evaluation factor 2, I would establish a threshold numerical value for rate of movement, above
which the rate is deemed to be significant. The rate would be established by modelling and also
by trends in monitor wells established in the vicinity of the interface. Pumping tests and cores
may also be required, particularly for vertical intrusion situations. A suggested starting point
for an estimate of a significant rate is that which would cause the interface to move 100 feet per
year for at least five years.

For evaluation factor 4, it may be useful to utilize a threshold trend rate of 10 mg/l chloride
increase per year for five years or more, as an indicator of significant intrusion. Others can
suggest how to quantify "unacceptable impacts to natural systems" (evaluation factor 6), however
I believe that reasonable data exists in the literature to show natural system sensitivity to
increasing chloride concentrations.

What are alternatives to the evaluation factors which are more reasonable, practical and
legally supportable?









Suggested alternatives have been discussed above and are included on an attached sheet.
Suggested numerical values are intended to initiate discussion. The main objective is to add
further definition to the somewhat vague wording of the proposed evaluation factors. Final
numbers could be higher or lower.

Other Comments

I have no problem with the increasing use of flow and solute transport modelling as a tool for
assessment of potential movement of the salt water interface, both laterally and vertically. The
District seems to putting a lot of effort in this direction. However my experience with these
models suggests that their results are not sufficient by themselves to document a problem unless
backed up with monitor well data or long-term water quality records from production wells.
Unfortunately these models seem to be evolving into a stand-alone decision tool by some
regulators, the results of which are regarded as correct even when they are contradicted or not
supported by actual field data. The models should be used as a tool in conjunction with other
methods before regulatory action plans are developed and implemented. The appropriate blend
of the various approaches to assessment of salt water intrusion potential will depend upon the
location and severity of the problem.

I hope that these comments will prove useful and look forward to receiving those from the other
reviewers in the near future.

Very truly ers,



R. David G. Pyne, PE.










Proposed Revisions to Evaluation Factors

R. David G. Pyne

July 30, 1993


Salt Water Intrusion

1. Reversal of vertical and/or horizontal directions of ground water flow in the immediate
vicinity of the interface.

2. Vertical or lateral movement of the salt water interface as measured by:

a lateral rate of at least 100 feet per year for a period of five years or more;

vertical interface movement as measured by chloride concentration increases of at least
10 mg/1 per year for five or more years in monitoring or production wells; or

as estimated based upon reasonable historic evidence such as abandonment of irrigation
wells due to deterioration in water quality.

3. Delete

4. A trend of increase in chloride concentrations of production or monitor wells over a
period of five or more years within an area surrounding a well or wellfield that is defined by
a drawdown of three feet or more.

5. Delete

6. Unacceptable impacts to natural systems caused by a trend of increasing chloride
concentrations.

Impacts to Existing Legal Users

1. Decline in water level such that a change in pump type, or a deeper pump setting, is
required by an existing user due to the new use.

2. Change in water quality such that additional treatment is required due to the new use.









Salt Water Intrusion
Evaluation Factors


1. Reversal of vertical and/or horizontal directions of
regional ground water flow

2. Vertical or lateral movement of the fresh/saltwater
interface

3. Potentiometric surface elevations at or below mean sea level
in the Floridan aquifer

4. Change in spatial distribution of chloride concentrations as
follows:

a. Water less than 250 mg/l
b. Water less than 1200 mg/l
c. Water less than 5000 mg/l

Note: These ranges are based on 250 mg/l as the EPA
recommended public drinking water standard, 1200
mg/l as the upper limit for agricultural
irrigation and 5000 mg/l as the upper limit for
cost-effective treatment of water for public
supply using reverse osmosis.

5. Change in chloride concentrations of water discharged
through springs or through upward discharge to the surficial
aquifer system such that unacceptable impacts to natural
systems would occur

6. Degradation of ground water quality to the extent that the
cost of treatment is not economically feasible and/or
unacceptable impacts to natural systems would occur


F










Impacts to Existing Legal User Evaluation Factors


1. Decline in water level such that a change in pump type is
required

2. Change in water quality such that an additional level of
treatment is required






H Y ROSCIENCES


GEOTECHNOLOGY


July 8, 1993


Ms. Barbara Vergara, P.G.
Director, Department of Groundwater Programs
and Technical Support
St. Johns River Water Management District
Post Office Box 1429
Palatka, FL 32178-1429


Re: Water Supply Needs and Sources Assessment Criteria Development; SJRF 010



Dear Barbara:


When you presented the results of this study to the Board of Directors of the West Coast
Regional Water Supply Authority in Clearwater a year ago, I liked the approach. After reading
the draft of the Water Supply Needs and Sources Assessment, it was apparent that a large amount
of effort went into obtaining the basic data and performing the groundwater modelling analyses.
My assessment is based entirely on the information in the report.


To develop assessment criteria implies selecting a standard against which future performance will
be measured. I believe that the report implies four major criteria: 1) vegetation; 2) groundwater
quality (more specifically the potential for saline water encroachment); 3) stream flow; and 4)
impact on other legal users.


The report focuses on the impact that groundwater withdrawals have had and (in the
future) will have on the vegetation, stream flow, and salt water intrusion. This is a very
important assessment and the report makes it clear that there are several areas (Figure 8) where
projected future water supply developments can have potential impacts on plant communities.
However, I am also interested in the question if the water resources system has reached its limit
and to identify other factors that may have an impact.




13412 N. LIcouJ AVENL'UE TAMPA., FLORItD 33618 TEi.ti':-ioN (813) 962.6690 FAX 813) Q62-6.60


1







HYDROSCIENCES
Ms. Barbara Vergara
July 8, 1993
Page 2


l i m CGO'OTECHNOLOGc


It is clear that when the groundwater system is stressed locally that the balance among
the major components of the hydrologic system will shift. These components are; I1 rainfall
input; 2) evaporation and transpiration outputs; 3) surface water inflows and outflows and; 4)
groundwater inflows and outflows. The classical expression simply is:
P ET + GWI GWO + SWI SWO = CS
in which
P = rainfall
ET = Evaporation and transpiration
GWI = Lateral groundwater inflow
GWO = Lateral groundwater outflow
SWI = Surface water inflow
SWO = Surface water outflow
CS = Change in water mass storage


If we assume that no surface water flows into the St. John's River Water Management District
(SJRWD), the equation can be simplified to:
P- ET + GWI GWO- SWO =CS
However, each one of these components is also interdependent. For example, GWO has
pumpage from the Floridan aquifer which can induce recharge, thereby increasing GWI;
lowering water levels in the surficial aquifer, thereby reducing ET. In areas where water may
be standing on the land surface for some time, pumpage may create additional storage in the
water table and capture rejected recharge. So pumpage may decrease ET loss thereby increasing

supply.


There is, however, another aspect to consider also. Groundwater pumped for a public
water supply is not all lost. Part of it is transferred to another system (surface water) as
discharge from a Waste Water Treatment Plant.







HYDROSCIENCES
Ms. Barbara Vergara
July 8, 1993
Page 3


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In Table 1 of the report, the water use by public supplies and agriculture were listed. I
assume that in this table the groundwater use is synonymous with ground water pumpag'. These
numbers were entered in the models. I estimate return flows at waste water treatment plants
maybe as low as 50 percent of the water pumped for public supply or as high as 70 percent.
This means that about half of the 1990 groundwater withdrawals of 427 MGD (213 MGD)
maybe transferred from the Intermediate and Floridan aquifers to surface water systems or
effluent disposal wells.


This "looping" effect within the water budget needs to be better understood and qantified
to gain a better understanding of the management options. To make it clear to myself, I
prepared a general water balance diagram enclosed as attachment A. This is my first attempt and
there is certainly room for improvement. The purpose of the diagram is to emphasize that the
entire hydrologic system is an integrated unit and to highlight the connections between the system
elements. It would be useful to quantify the inter-connections on the diagram. My attempts at
quantifying the inputs and outputs per year are shown on the diagram. In my calculations, I
estimated the district surface area as 14,400 square miles.


I was interested in determining the change in water mass over time. To gauge the impact-
that continued water resources development may have on the overall water resource, I used the
data in Table 1 to evaluate the losses to the system from ground and surface water withdrawals.
Total groundwater and surface water withdrawals in 1990 were estimated at 1.5 inches er year
which is 37.5 percent of the district wide net recharge to the surficial aquifer. Unfortunately,
this pumpage occurs in concentrated areas, thus causing significant water level changes in the
surficial aquifer. It is interesting to note that the water table declines range from less than 1 foot
to more than 2.5 feet according to Figure 7. This is in response to a total pumpage in 2010 of
1355 MGD according to Table 1. This translates to approximately 2.0 inches per year.
Applying a rule of thumb relationship that 1 inch of net rainfall recharge will raise the water
table by approximately 1 foot, an average 2 ft decline in water level correlates to a withdrawal


O. TF...N...LOC
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~~1D


HYDROSCIENCES
Ms. Barbara Vergara
July 8, 1993
Page 4


of 2 inches per year. A slight inconsistency is the fact that the 2 inches per year pumpage is
based on the entire district area, however, pumping impacts are limited. I assumed that 50
percent of the ground water pumped is lost to ET and that 70 percent of the surface water is lost
to ET. In 1990, 564 million gallons per day (MGD) were lost to ET. In 2010 that loss is
projected to increase to 865 MGD, a 54 percent increase. Assuming that the remaining 50
percent of ground water is discharged to streams and the remaining 30 percent of surface water
is discharged to the surficial aquifer, the total internal transfer of water is (212+110) 322 MGD.


The additional ET loss in 1990 is equivalent to 0.8 inches per year, and the 2q0 loss is
1.2 inches per year. Compared to the normal 52 inches per year of rainfall, this additional ET
loss is insignificant regionally, but may be locally significant.


The report indicated that water table elevations in some areas may decline by 2.5 feet or
more. This has a significant effect on vegetation, but it also creates an additional storage
opportunity to capture rejected recharge.


In summary,


1) In developing the criteria for surface water, I suggest that your team consider the transfer
of groundwater to surface waters via WWTP discharge and its effect on maintaining base
flow.


2) I believe it to be useful to better delineate and quantify the inter-connections within the
major hydrologic system. I believe that a better quantitative description of the hydrologic
"loops" in the system will facilitate water resource planning and management.


3) It will be important to evaluate where the potential for lateral and vertical saline and
mineralized water movement will be increased by withdrawals.


GEOTECHNOLOGY






HYN-ROSCICNCES mI^P n~mHInm h Gh'-UECHNOLOGY
Ms. Barbara Vergara
July 8, 1993
Page 5

4) All supply enhancement alternatives provided by the team should be entered into a
decision matrix, along with the previously mentioned evaluation criteria. Construction
and O&M cost for the alternatives should be added as a criterion.


5) In addition to these alternatives, I suggest considering the mitigation of well field areas
with reclaimed water.


6) Also, the potential use of reclaimed water for saline water mitigation barriers along
coastal areas may have some merit if DEP regulations can be satisfied. Barbar, I hope
that this reflection on your project is helpful. There is much more that can be said,
which I presume will be the focus of the upcoming meeting.







Sincerely Yours,
SCHREUDER, INC.



Peter J. Schreuder, PG
President






































ATTACK M C-MT


JOirs AFR1 I C.eHs/Y/ YA







0;TAKE I
United States Department of the Interior AE -

GEOLOGICALSURVEY
WATER RESOURCES DIVISION
R I TT I'MGT OtSCr 24 West Central Parkway, Suite 1006
7 Altamonte Springs, Florida 32714
,JUN 4 10 (407) 648-6191
i._ J 1 June 21, 1993




Ms. Barbara Vergara
St. Johns River Water Management District
P.O. Box 1429
Palatka, FL 32078-1429

Dear Barbara:

I am pleased to participate in the St. Johns River Water Management District's
project to develop its Water Supply Needs and Sources Assessment Criteria.

As per your request dated June 15, 1992, I have studied your lists of
evaluation factors for salt water intrusion and existing legal user criteria.
My comments are developed from the perspective of a hydrologist in an
agency that has no regulatory function. Therefore, my observations may not
always lend themselves to direct incorporation into useful regulations.
Further, because of USGS policy guidelines, I did not suggest alternative
criteria.



EVALUATION FACTORS

Impacts to existing legal user:

1. Decline in water level such that a change in pump type is required:

I believe that this criterion is intended to recognize that reduction of
ground-water levels due to pumping (or drought) can cause water levels in
some wells to occasionally or persistently decline below the level that a
centrifugal pump can function and that a different type of pump, such as a
submersible or a turbine, must be installed. An even broader criterion
would be one that recognizes that water levels can decline to the extent
that even submersible pumps and the impellers on turbine pumps might be
required to be lowered in order to effectively pump water.

One problem in setting up enforcement criteria might be the difficulty in
separating the effects of man-made causes of lowered water levels from that
caused by drought. Another problem to assess would be the random "hits"
where the pump problems might occur, especially where submersible or
turbine pumps would need to be lowered.






2. Change in water quality such that an additional level of treatment is
required:

It is probable, though not 100% certain, that a degradation in water
quality will be preceded or accompanied by lowered ground-water levels
which can be the result of pumping or drought. The point here is that it
is difficult to separate the causes and effects of man-made versus natural
stresses and it is even more difficult to predict the extent of the
accompanying degradation of water quality and the time period over which it
might occur. Those matters aside, another question is what is meant by
"required" level of treatment? If it refers to public water supplies, then
the matter is fairly straight-forward in terms of legal requirements. If
it also refers to domestic users, irrigation users, and industrial users,
there are no legally-required levels of treatment so it really becomes a
matter of physical tolerance or economic tolerance.


Salt-water intrusion:

1. Reversal of vertical flow and/or horizontal directions of regional ground-
water flow:

I am presuming that, in this discussion, we are talking about aquifers, not
confining beds, and that reversed vertical flow always means the change of
downward (and lateral) vectors of flow in aquifers to the extent that there
would be upcoming from deeper levels in the aquifer.

It would probably be best if the issues of reversed vertical flow and
reversed horizontal flow were considered separately.

In the instance of reversed vertical flow, I am not sure that you can do
much here. Consider that partially-penetrating wells will always induce
upward flow from deeper levels and that fully-penetrating wells will not
induce upward flow (not from the same aquifer, anyway). Now consider that
the fully- or near fully-penetrating wells will tend to be deeper than the
partially-penetrating wells and thus will be in closer proximity to poor
quality water that can lay at depth. Paradoxically then, the pumping well
that causes the least upcoming will be the well that is most vulnerable to
upcoming of saltwater.

As for reversed horizontal directions of flow, there may good reason to use
this as a criterion as long as some sort of scale factor is recognized. In
other words, what is the definition of "regional" -- 1 square mile, 10,
100, or 1000? Another factor to consider is the area's lateral proximity
to poor quality water and how a pumping center's lateral "capture zone"
impinges on the area that contains the salty water. A third factor to be
considered might be the length of time before the salty water reached the
pumping center or before it adversely impacted another user that happened
to be in its path.












118







2. Vertical or lateral movement of the freshwater/saltwater interface:

My comment here is essentially the same as for item 1 except that you would
decide on how much movement is acceptable, whether that movement will
impact existing or future users, how long will it take before that impact
is realized, whether a new equilibrium will become established after the
initial movement, and whether that new equilibrium will occur before there
are adverse impacts.


3. Potentiometric surface elevations at or below mean sea level in the
Floridan aquifer system:

This could well be a valid criterion. However, the Fernandina Beach cone
of depression comes to mind as an exception -- the cone has been well below
sea level for at least 50 years and, thus far, the quality of the water
pumped has not degraded to the extent one might expect. Why is 0 feet
above sea level used as the breakpoint criterion? Why not 5 feet or 10
feet above sea level? If Ghyben-Herzberg is used as a tool, a
potentiometric level of say 5 above mean sea level feet might dictate a
potential interface depth of 200 feet. Is this enough of a buffer? A
minimum level of 0 feet above sea level allows for essentially no buffer at
all'.


4. Change in spatial distribution of chloride concentrations as follows:


a.
b.
c.


Water less than 250 mg/L
Water less than 1200 mg/L
Water less than 5000 mg/L


I'm proceeding under the assumption that what is meant here is, in each
instance, the native aquifer water has a chloride concentration of less
than 250 mg/L, 1200 mg/L, or 5000 mg/L, respectively, and that you want to
determine if those waters need to be protected. Also, I am assuming that
the "change" referred to always means an increase rather than a decrease in
chloride concentration.

I would agree that the upper limits listed are logical breakpoint
criterion. They are measurable and appear to be reasonably defensible.
The predictability of the changes would remain problematical.


5. Change in chloride concentrations of water discharged through springs or
through upward discharge to the surficial aquifer system such that
unacceptable impacts to natural systems would occur:

Again, assuming that "change" means an increase and that natural changes
can be distinguished from man-made changes, you presumably would have to be
able to make a further determination of the chloride tolerances of each
plant and animal species of the "natural" system. I am definitely out of
my area of expertise here.








6. Degradation of ground-water quality to the extent that the cost of
treatment is not economically feasible and/or unacceptable impacts to
natural systems would occur:

I think that this criterion should be two separate criterion -- economic
impacts and impacts to natural systems.

I do not feel comfortable in commenting on the economic aspects except to
say that economic damages can be argued in many different ways.

In terms of impacts to natural systems, my comments are essentially the
same as those given in item 5.






Barbara, if you have any questions, please call me.



Sincerely,



Charles H. Tibbals
Subdistrict Chief


cc: Doug Munch, SJRWMD
Bob Schultz, SJRWMD










CARLTON, FIELDS, WARD, EMMANUEL, SMITH & CUTLER, P. A.
ATTORNEYS AT LAW

Y HARBOUR PLACE FIRSTATE TOWER HARBOURVIEW BUILDING FIRST FLORIDA BANK BUILDING ESPERANTE BARNETT TOWER
P.O BOX 3239 P BOX 117 PO BOX 12426 P.O. DRAWER 190 P.O. BOX 150 P.O. BOX 2861
PA. FLORIDA 33601 ORLANDO. FLORIDA 32802 PENSACOLA. FLORIDA 32502 TALLAHASSEE. FLORIDA 32302 WEST PALM BEACH. FLORIDA 33402 ST. PETERSBURG. FLORIDA 33731
(813) 223-7000 (407) 8490300 (904) 434-0142 (904) 224-585 (407) 659-7070 (813) 821-7000
k(1B3) 229-4133 FAX (407) 648-9099 FAX (904) 434-5366 FAX (904) 2220398 FAX (407) 659-7368 FAX (813) 822-3768 .

PLEASE REPLY TO :
VIA TELECOPY Tallahassee

July 30,.1993

MEMORANDUM St JO S RIVER WAI[ ;1 0.,'..

TO: BARBARA A. VERGARA

FROM: Jake Varn A

RE: ANALYSIS OF POTENTIAL EVALUATION MAL R
FACTORS FOR WATER USE PERMIT

In carrying out its statutory responsibility under Chapter
373, Florida Statutes, a water management district must determine
if a proposed withdrawal of water and its proposed use:

(1) are a reasonable-beneficial use,

(2) will not interfere with presently existing legal users
of water, and

(3) are consistent with the public interest.

If an applicant can demonstrate compliance with each of the
foregoing criteria, the applicant is entitled to a permit
authorizing the withdrawal and use.

The current scope of work asks us to focus on salt water
intrusion and impacts on existing legal users. It should be
noted that these are only two of many factors to be considered in
determining whether a proposed withdrawal and use are reasonable-
beneficial. Further, it is my opinion that a reasonable-
beneficial use cannot interfere with any presently existing legal
use of water. Thus, I view and consider interference with others
as a factor of the reasonable-beneficial use test. It is also my
opinion that a water management district should not grant a water
use permit for a proposed withdrawal and use, if the proposed
withdrawal and use cause salt water intrusion.

While Florida has adopted the "reasonable-beneficial" use
standard, many aspects of the common law doctrine of reasonable
use are retained in the "reasonable-beneficial" use standard.
Accordingly, it is helpful to review and understand the


YY#27815.1










MEMORANDUM Barbara A. Vergara
July 30, 1993
Page Two


reasonable use standard as applied to ground water withdrawals
and use. A person owning property overlying ground water has a
right to make a reasonable use of those underlying waters. This
right of use is known as a usufructuary right. Under the common
law, a wasteful use of water could be a reasonable use. The use
would become unreasonable only if the wasteful use caused harm or
interfered with other reasonable uses. One of the express
purposes of establishing the "reasonable-beneficial" use standard
was to eliminate wasteful uses of water. Consequently, what was
a reasonable use under the common law may not be a "reasonable-
beneficial" use under Chapter 373, Florida Statutes.

Reasonable use under the common law varied with time and
use. Reasonable use also depended on how the overlying
landowners were using the water. Under the reasonable use
doctrine, the courts accommodated as many reasonable uses as
possible. Also, the use of the water on the overlying land was
viewed as being more reasonable than large withdrawals for use
elsewhere. The courts have long recognized that water used on
the overlying land has some probability of finding its way back
into the aquifer, whereas, water removed from the overlying land
has little or no chance to find its way back into the aquifer.

Reasonableness varies with the circumstances. It is usually
reasonable to give equal treatment to persons similarly situated
and to subject each to similar burdens. However, equal treatment
does not mean equal quantities of water. At common law, if
Farmer A is the first to drill an irrigation well and the well
becomes inadequate when Farmer B and Farmer C irrigate their
lands, the courts held that Farmer A had not been interfered with
by the new users if he is forced to deepen his well or install
new pumps. On the other hand, if Farmer A faced the same
problems as a result of large withdrawals of water for use at
distant places by XYZ Corporation, XYZ Corporation is liable to
Farmer A. As a practical matter, in many cases for the person
interfering with another the solution is to supply the needs of
the person harmed by the large withdrawals. Placing liability on
the person causing the interference will encourage this result.
The courts, in determining where to place the burden, usually
also consider the relative position of the parties and their
capacity to bear the burden.

The courts have always given preferential treatment to
domestic uses of water. As between domestic users courts have
generally held that one domestic user does not interfere with
another domestic user. It is important to understand that
domestic use does not include the withdrawals of municipalities
or other water suppliers for domestic use on distant lands.


YY#27815.1









MEMORANDUM Barbara A. Vergara
July 30, 1993
Page Three


On the other hand, if Farmer A interferes with a domestic
user, Farmer A is required to make the domestic user whole.
However, the domestic user must exercise due diligence in
constructing its well, especially if the well is constructed
subsequent to Farmer A's well.

With respect to the evaluation factors proposed by the
District, I have several concerns. First, there is no
quantification of the salt water intrusion factors. For example,
how much vertical or lateral movement of the fresh/salt water
interface is permissible? Further, how much change in spatial
distribution of the chloride concentrations is permissible?
Theoretically, every withdrawal of ground water will cause some
amount of salt water intrusion.

Second, it is my opinion that you cannot look at salt water
intrusion or impacts on other users without looking at all of the
factors of what constitutes a reasonable use. Third, ultimately
the District will have to deal with each user. In my opinion, it
is inappropriate to deny one proposed water user a permit if that
proposed use happens to be the use that violates some pre-
determined standard (i.e., the proposed use is the straw that
breaks the camel's back). It is my view that the violations
result from the cumulative impact of many users and not the
single user.

REGULATORY APPROACH

With this background, it would be my recommendation that in
order to implement a regulatory program, the District's first
step is to have an understanding of its ground water system. As
part of this process, the District should be divided into ground
water basins. Within each basin the District would establish a
number of factors, including the maximum amount of ground water
withdrawals that can occur. In addition, the District would
establish levels throughout the basin below which the ground
water could not be withdrawn. Ground water levels should be
established to ensure that salt water intrusion does not occur.
I should point out that I would not envision the District
undertaking efforts at this stage to deal with the "interference"
issue. The foregoing has been described by some as a basin-wide
safe yield determination.

Once the basin-wide criteria is established, the District
would evaluate individual permits to ensure that the proposed use
would not, in combination with the other users, violate any of
the basin-wide criteria. Obviously, the District wants to avoid



YY#27815.1










MEMORANDUM Barbara A. Vergara
July 30, 1993
Page Four


issuing permits that would cause a violation of its basin-wide
criteria. In implementing its regulatory program, within each
ground water basin the District should establish a common
expiration date for all permits. It is critical to evaluate all
users and proposed users at one time. If all users and proposed
users are not evaluated at the same time, it will be virtually
impossible to ensure that the District is achieving the most
reasonable-beneficial use of its water resources. Another
important factor is that the term of the permits should decrease
as the total water usage approaches the safe yield within the
basin. For example, once total :wter use reaches 80% of the safe
yield, permits should not be effective longer than five years.
Further, it would be my recommendation that the District
designate some amount of water for future users. Obviously, the
shorter the permit period, the smaller amount needed for future
users.

The utilization of the foregoing process should effectively
prevent any type of salt water intrusion.

One of the factors proposed for evaluating salt water
intrusion was to determine if the degradation of the quality
would cause unacceptable impacts to natural systems. It is my
view that the protection of natural systems is required at the
beginning of the process. Water required for natural systems
should be determined and protected prior to establishing the safe
yield for a basin and prior to issuing water use permits.

With respect to determining impacts to existing legal users,
this determination can only be done on a case-by-case basis. In
determining what constitutes an interference, the District needs
to determine when a use becomes harmful. What is harmful to a
domestic user is probably not harmful to a farmer using water for
irrigation purposes. Determining what is harmful also requires
one to take into account who is in the best position to share the
burden.

As to the work of the consultants, I would suggest that we
develop a number of examples where interference is alleged and we
work out when "interference" has occurred and what the
appropriate remedy is.

I shall look forward to discussing these matters with you
and the others at our first meeting.

JDV:dgb




YY#27815.1


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