AN EVALUATION OP
SEPTIC LEACHATE DETECTION
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AN EVALUATION OP
SEPTIC LEACHATE DETECTION
by
Patricia L. Deese, P.S.
Urban System Research and Engineering, Inc.
Cambridge, Massachusetts 02138
Contract No. 68-03-3057
Project Officers
James F. Kreissl
Robert P. G. Bowker
Wastewater Research Division
Water Engineering Research Laboratory
Cincinnati, Ohio 45268
WATER ENGINEERING RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with
protecting the Nation's land, air, and water systems. Under a mandate of
national environmental laws, the agency strives to formulate and imple-
ment actions leading to a compatible balance between human activities and
the ability of natural systems to support and nurture life. The Clean
Water Act, the Safe Drinking Water Act, and the Toxics Substances Control
Act are three of the major congressional laws that provide the framework
for restoring and maintaining the integrity of. our Nation's water,' for
preserving and enhancing the water we drink and for protecting the envi-
ronment from toxic substances. These laws direct the EPA to perform
research to define our environmental problems, measure the impacts, and
search for solutions•
The Water Engineering Research Laboratory is that component of EPA's
Research and Development program concerned with preventing, treating, and
managing municipal and industrial wastewater discharges; establishing
practices to control and remove contaminants from drinking water and to
prevent its deterioration during storage and distribution; and assessing
the nature and controllability of releases of-toxic substances to the
air, water, and land from manufacturing processes and subsequent product
uses. This publication is one of the products of that research and pro-
vides a vital communication link between the researcher and the user
community.
Recognizing that nearly eighty (80) percent of the municipal waste-
water facilities needed by the year 2000 are located in small communities
and that the per capita cost of those facilities are far higher in these
rural communities than in urban areas, there is a need to improve facility
planning in rural regions to avoid unnecessary capital expenditures. This
document analyses and discusses one of the newly developed techniques
purported to improve facility planning for rural lake communities.
Francis T. Mayo, Director
Water Engineering Research Laboratory
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DISCLAIMER
The information in this document has been funded wholly by the United
States Environmental Protection Agency under Contract No. 68-03-3057 to
Urban Systems Research and Engineering, Inc. It has been subject to the
Agency's peer and administrative review, and it has been approved for
publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
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ABSTRACT
This study subjects Septic Tank Leachate Detection (SLD) technology
to a critical analysis, focusing on these primary issues: the proposed
hypothesis of its functioning; its status of development and performance
to date; and its cost-effectiveness. Functionally, these devices measure
fluorescence and, in some cases, conductivity. The sources of the compounds
which register on these types of measurement are widespread and non-specific
to septic tank leachates. There is negligible evidence to' support the
assumption that distinct and identifiable plumes could exist in zones of
groundwater entry into lakes, except in a very few specialized instances
.such as perched water flow over confining bedrock.
Facts which indicate that SLD devices are only in an early develop-
mental stage include the lack of false negative ratio quantification,
i.e., missing a plume when one exists. A statistical analysis of existing
SLD survey data shows that the false positive ratio to be in the neighbor-
hood of 30 percent, i.e., of thirteen identified plumes three will be false
readings. No useful screening tool can be reliably employed until the
false negative ratio is established to be very low and the false positive
ratio is cost-effective. A method of quantifying these factors is proposed.
Fi'nally, available cost information does not appear to be particularly
favorable to SLD surveys due to the limited effective distance from the
shoreline to the septic tank-soil absorption system (25 meters) and the
need for limited, follow-up sanitary surveys.
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CONTENTS
Foreword iii
Abstract iv
Figures and Tables vi
Acknowledgement vii
1. Introduction . 1
2. Conclusions and Recommendations 9
3. Septic Leachate Detection Theory 13
4. Evaluation of Septic Leachate Detection 20
References 38
Appendices
A. Field Experience Data and Analysis A-1
B. Statistical Methods B-1
C. Detailed Concept Questionnaire and Responses C-1
D. -Reviewer Comments D-1
E. List of Persons Contacted During Study E-1
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FIGURES
Number Page
1 Illustration of septic system leachate plume entering lake ... 3
2 Optimal operation procedure for an SLD device 15
3 Sample frequency distributions and probabilities of significant
differences using the student T-test 28
4 Results of student T-test using 30% decision rule and omitting
surveys with only one background sample 29
5 Results of student T-test using 30% decision rule using all
survey data 31
6 Results of student T-test using 30% decision rule for
groundwater samples 32
TABLES
Number Page
1 Description of septic leachate detection 5
2 Double blind controlled conditions experiment for
SLD accuracy 12
3 Characteristics of typical residential wastewater 17
4 SLD surveys reviewed 25
5 Information provided by alternative wastewater planning . . . .33
6 Hypothetical community developed by Peters and Krause (1980) . . 35
7 Comparative cost analysis of SLD suveys and sanitary surveys . . 36
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ACKNOWLEDGEMENTS
A number of people have contributed to the preparation of this report
during its many stages of development. Any errors of omission or
commission, however/ remain the responsibility of the author.
Special thanks go to the Project Officers and staff of the Water
Engineering Research Laboratory of the Environmental Protection Agency,
Robert Bowker, James Kreissl and James Cox. Their guidance and direction
have been essential in ensuring the quality of the research and of this
report. The research would not have been possible without the cooperation
of the developer, manufacturers, and clients of SLD surveys. The assistance
of Larry Feldman of Goldberg Zoino Associates was also invaluable.
The development of this report required key contributions from a
number of past and present USR&E staff members and consultants. Dave
Burmaster, Cynthia Ernst, Margaret Jensen, Valerie Bradley, John Best, and
Susan Parrell all participated in all various aspects of the report.
Finally, the efforts of Cynthis Daley in the final production have been
exceptional.
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SECTION 1
INTRODUCTION
1.1 PURPOSE
Under the small community pollution abatement program, the-
Environmental Protection Agency's Municipal Environmental Research
Laboratory is reviewing several techniques which may improve the wastewater
planning process for non-'sewered areas. The purpose of this report is to
evaluate Septic Leachate Detection (SLD) as a method for identifying areas
where on-site wastewater systems adversely impact lake water quality.
The evaluation focuses on the following questions:
1. Is the SLD hypothesis supported by wastewater treatment,
groundwater movement, water quality monitoring, and limnologic
theory?
2. Do SLD surveys improve mass balance analysis methods?
3. Is SLD currently in the research development or demonstration
phase?
4. Are SLD surveys more cost-effective or do they provide more
information than shoreline, mass balance, or other traditional or
non-traditional evaluation methods?
1.2 THE PROBLEM
Paced with the deterioration of water quality, authorities often
assume that effluent from on-site domestic wastewater systems is a primary
source of contamination. This assumption should be carefully verified
before a community commits itself to an expensive sewage collection system
designed to completely eliminate effluent discharges to the lake.
Documenting a cause and effect relationship between deteriorating
surface and groundwater quality and the use of on-site systems has long
been a challenge. Wastewater facility planning techniques available for
the task include review of local health department records, mail or
door-to-door sanitary surveys, shoreline and windshield surveys,
identification of other potential contaminant sources, hydrologic and
geohydrologic studies, and ambient water quality monitoring. While
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conventional shoreline surveys often reveal direct discharge drains, storm
drains, wetlands, unusual concentrations of algae or rooted aquatic plants,
and tributaries there is no convenient or generally accepted way to verify
the existence, location, or impact of subsurface effluent plumes using
conventional planning techniques.
Traditionally, wastewater facility planners gather information using
some combination of the above techniques, and then use mass balance
analysis to estimate the potential impact of domestic wastewater on the
lake. The question addressed by this report is whether SLD surveys could
make a significant contribution to such evaluations by either improving or
expediting the current approach.
1.3 DEFINITION OP SEPTIC LEACHATE DETECTION (SLD)
Septic Leachate Detection (SLD) is based on the theory that effluent
from on-site wastewater systems forms detectable subsurface effluent plumes
which travel through the groundwater system and emerge intact into a lake.
The diagram in Figure 1 has been used in numerous SLD reports to illustrate
this theory of subsurface ef.fluent plume movement.
Developing a methodology for proving the existence of a subsurface
effluent plume entails three preliminary steps. First, the water quality
variables to be used as indicators of the effluent plumes must be
selected.. Second, the criteria to be used for determining the existence of
plumes must be set. These criteria should take the form of recognizable
and reproducible deviations from background concentrations of the indicator
water quality variables. Third, standard procedures for data collection
and analysis must be established.
In theory, data for such surveys could be collected using any number
of ambient water quality monitoring techniques. However, verifying the
location of plumes emerging along the shoreline with traditional grab
sampling procedures presents unique problems. However, a monitoring device
which continuously measured levels of the desired water quality indicators
and instantly recorded changes in their concentrations could be used to
pinpoint emerging subsurface effluent plumes. Traditional grab samples
could then be analyzed to verify the presence or absence of such plumes.
At the time of this writing', there are two commercially available
water quality monitoring devices designed specifically for use in SLD
surveys. Environmental Devices Corporation, (ENDECO) manufactures the
ENDECO Type 2100 Septic Leachate Detector (Septic Snooper™), which uses
both fluorescence and conductivity as indicator parameters. K-V Associates
has recently introduced the Model 15 septic Leachate Detector (Peeper
Beeper™), which monitors contaminants solely by fluorometric analysis.
When data collection on this analysis began, only the Septic Snooper™ or
a modified Septic Snooper™ owned by K-V Associates were used for SLD
surveys. The results of this report, then, are based on surveys completed
with those devices, and not the Peeper Beeper™.
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SEPTIC LSACHATE-^
Figure 1. ILLUSTRATION OF SEPTIC SYSTEM LEACHATE PLUME ENTERING LAKE (EMI, 1976),
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USEPA Region V has sponsored a number of SLD surveys as part of its ''
Seven Rural Lakes project. Based on this experience/ the SLD is described
at length in the Final Generic Environmental Impact Statement for
Wastewater Management in Rural Lakes Areas. The description has been
reproduced in its entirety in Table 1.
1.4 RESEARCH METHODOLOGY
The findings of this report are based on analysis of information from
numerous sources:
o General literature in the disciplines of groundwater movement,
on-site wastewater systems/ ambient water quality/ and limnology
•o Published and unpublished SLD survey reports
o Observation of a shoreline survey conducted using the Septic
Snooper™
o Participation in a Septic Snooper™ training course.
o Interviews with the Septic Snooper™ developer, manufacturer,
users/ and client communities
o Consultations with experts in groundwater hydrology/ limnology,
ambient water quality monitoring, on-site wastewater systems, and
statistical analysis.
Information about the SLD concept was gathered during the initial
phase of the research. A detailed literature review and consultations with
experts in the various scientific disciplines were used to determine
whether the SLD hypothesis is supported by wastewater treatment,
groundwater movement, water quality monitoring, and limnologic theory. The
water quality data generated by SLD surveys were also analyzed to determine
whether the survey results met the basic criteria for scientific proof:
repeatability and statistical significance. The draft report was then
submitted to experts for reveiew and comments. The conclusions of this
report are based on the findings of these analyses.
Section 2, that follows, presents the conclusions and
recommendations. Section 3 analyzes the theoretical assumptions underlying
the SLD concept/ while Section 4 reviews field experience with the Septic
Snooper™. Appendix A presents data from early SLD Surveys/ and Appendix
B describes the statistical methodology used to analyze that data. The
comments submitted by the developer and manufacturer of the Septic
Snooper™ can be found in Appendix C, while Appendix D presents the
comments made by reviewers of the draft report. Finally, Appendix E lists
the individuals contacted in the preparation of this report.
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TABLE 1. DESCRIPTION OF SEPTIC LEACHATE DETECTION (WAPORA, 1983)
Currently available septic leachate detectors can be used to locate ground-
water inflows or surface runoff conveying domestic wastewater into lakes.
The operational theory of the detector depends on the assumptions that
fluorescent organic materials are present in wastewater and that inorganic
chemicals will be present in wastewater at higher concentrations than, in
ambient groundwater or surface water. Detection of both increasing
fluorescence and increasing conductivity in water drawn by pump from a
shoreline provides tentative evidence of the presence of domestic waste-
water. Because of the high sensity of their fluorometers, currently
available detectors can rapidly locate groundwater effluent plumes and
wastewater in surface runoff where wastewater is otherwise undetectable.
This- tool proved to be invaluable in studies that addressed the impacts of
on-site systems on lakes studied for the Seven Rural Lake EIS's.
The septic leachate detector is subject to certain limitations that must be
recognized in its use and in interpretation of the data it generates. The
most significant limitation is that it cannot quantify the strength of
wastewater in a sample or body of water. The organic and inorganic para-
meters that it monitors can be transported through soil and water quite
independently of other wastewater constituents. Even the fluorescence and
conductivity are recorded in relative, not quantitative, units. In order
to quantify the concentrations of nutrients, bacterial, or other wastewater
constituents, flow through the meter can be subsampled or samples can be
collected by conventional means for Later analysis. The advantage of the
detector is that it permits collection of samples in suspected effluent
plumes so that random sampling is avoided.
Aside from the limit on quantification, septic leachate detector surveys
are subject to false positives and false negatives. Most of these
potential errors are due to the dynamic nature of the natural systems
involved and to variability in wastewater characteristics. False positives
can be caused by:
• Naturally fluorescent decay products from dead vegetation. Swamps,
marshes and peat deposits can leach tannins, lignins and other organic
compounds that fluoresce in the detection range of the fluorometer. The
conductivity measurements provided by the detector are intended to
differentiate such signals, but in practice dilution may eliminate
detectable conductivity changes expected from vastevaters, thus making a
wastewater plume appear to be the same as natural decay products.
• Sediment or air drawn through the detector can cause dramatic changes in
the monitor readings. This is usually noted by the operator and
recorded on the recorder tape.
• Eddy currents carrying large wastewater or bog plumes can appear to be
individual plumes from on-site systems.
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TABLE 1 (continued)
The more serious errors are false negatives since they may indicate no
problem where actual problems might exist. Notable false negatives are:
• As mentioned above, high dilution of wastewater in lake or groundwater
may reduce conductivity differences to the level of normal background
variations.
The absence of conductivity differences will cause the detector to
electronicly mask fluorescence signals that are detected.
• Mixing of lake water by wind and waves can disperse leachate very
rapidly so that normally strong effluent plumes can be missed al-
together. .The time it takes for leachate to accumulate along a
shoreline to detectable concentrations is dependent on several, so far
unstudied, factors.
• Fluctuations in lake level can slow or even reverse normal groundwater
flow, temporarily eliminating leachate emergence at a shoreline.
• Groundwater recharge by. rainfall, snowmelt or irrigation will also
affect the dynamics of leachate movement.
• Seasonal use of dwellings may result in only periodic emergence of
leachate at a shoreline.
Due to these factors, the data generated by septic leachate detectors has
to be carefully interpreted before it can be considered to be useful
information. Interpretation is aided by supplementary data collected or
recorded before, during, and after the shoreline scan as noted:
Before
watershed boundaries
groundwater aquifer characteristics
groundwater flow as determined by meters or other methods
soil types
wetlands and other sources of organic decay products in the watershed
locations of surface malfunctions identified by aerial photography
interpretation
• information on design, usage, and performance of onsite systems if
available
• changes in lake elevation.
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TABLE 1 (continued)
• weather conditions - especially wind, speed and direction, and -recent
rainfall
• lake stratification and surface currents
• observed nog-wastewater sources of fluorescence or conductivity such as
culverts, drainage ditches, salt storage areas, landfills, abundant
organic material in near-shore sediments
* observed direct discharges
• likely proximity of on-site systems near shoreline
• operational mishaps such as stirred up sediments, air drawn through
meter and engine backwash
• sensitivity and zero adjustments for fluorescence and conductivity
channels
• frequent notation of visual meter readings
• location, time, and conditions of water sample collection.
After
• water sample analysis results.
Because of the possibilities for error and the many factors influencing the
result of septic leachate detection, the validity of surveys rests heavily
on the experience, knowledge, and judgment of the surveyor. Until addi-
tional evaluation is made of the factors influencing survey results, septic
leachate surveys will be eligible for Construction Grants funding only
when:
1) the person in charge is experienced in operation and maintenance of the
detector model being used. At least two weeks of field experience is
necessary assisting someone who is already expert with the model,
2) the person in charge is present during any shoreline scans that are
reported,
3) data is interpreted by a person who has a professional background in
limnology, and
4) approximate wind speed and direction are noted during the survey and
reported.
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TABLE 1 (continued)
Septic leachate detectors should prove to be valuable monitoring tools for
communities managing shoreline on-site systems. Purchase of detectors will
be eligible for Construction Grants funding. Grantees will be required to
show that comparable instruments are not available on a timely basis from
other nearby grantees. Funded instruments will be made available to other
grantees.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
2.1 CONCLUSIONS
Summary
The septic leachate detection (SLD) concept rests on two assumptions
about the behavior and characteristics of septic effluent in lake shore
regions. The first assumption is that septic leachate plumes usually exist
in the groundwater and often migrate toward lakes. This assumption is
supported by both groundwater theory and empirical evidence. The second
assumption is that septic leachate plumes emerge into lakes in a discrete,
intact, and identifiable form. While groundwater theory supports the
condition that the plume may be identifiable, in many instances it will not
be.
For a plume to be identifiable it must be of sufficient strength,
quantity, and velocity to resist dilution; it must be of sufficent cross
sectional area to insure, with a reasonable probability, that the SLD
device will pass through the plume; and the SLD device must measure a water
quality parameter which is consistently representative of septic system
leachate. There are problems with each of these conditions.
Plume velocity and concentration are both inversely related to plume
cross sectional area. Because of this, groundwater theory predicts that a
given plume may range from relatively concentrated with a small cross
sectional area and high velocity, to relatively dilute with a large cross
sectional area and low velocity. As a result, the strong plumes could be
easily missed because of their small cross sectional area. The large
plumes, on the other hand, could be too dilute to detect, and are quickly
dispersed into the lake water. Groundwater theory also predicts that the
maximum plume velocity is .002 cm/sec. The ability of plumes to resist
dilution in the littoral zone at this rate is questionable.
There is also a problem with the parameter used to indicate the
presence of the plume. SLD devices currently on the market measure a
combination of conductivity and fluorescence, or simply fluorescence.
There are many natural sources of flourescence other than septic leachate
plumes in the lake environment that could theoretically actuate the
device.
Practical experience does not support the concept of the SLD surveys
either. In the fifteen SLD surveys reviewed for this study, there is
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little empirical evidence supporting the assumption that septic leachate
plumes are distinct and identifiable. There has been no controlled
research to document the false positive and false' negative rate of SLD
surveys. What limited field evidence there is, suggest that the false
positive rate is above 30%. Such a high rate is a strong indication that
the device is often actuated by natural phenomena other than the presence
of a septic leachate plume.
False positives result in an overestimation of the contribution of
septic leachate to water quality problems. In a screening tool such as
this, they could lead the facilities planner to take so many grab samples
to prove the existence of a plume, that the cost advantages of using the
device to screen for potential problems are lost.
There is no field documentation of false negative rates. Since each
false negative represents a pollution source which has been missed by the
survey, it is imperative that the frequency of false negatives be
relatively small. Otherwise, the screening tool can grossly underestimate
the septic leachate problem and cause planners to make poor decisions about
wastewater treatment needs. The rate of false negatives is independent of
the rate of false positives and must be documented through both laboratory
and field experiments before the data from SLD surveys can be considered
valid.
SLD surveys are designed to screen for septic leachate plumes. Grab
samples of the lake water must be used to confirm or deny the presence of a
plume. SLD surveys are relatively expensive when compared to sanitary
surveys but may be less expensive than detailed groundwater monitoring at
individual lots.
As presently espoused, SLD surveys can only locate septic leachate
plumes which are from systems within 25 meters of the lake and which remain
discrete and identifiable after reaching the lake. An underlying
assumption is that identifying these plumes is important. However, for
many lakes the major source of nutrient loading may be from systems which
are not included in the SLD survey because they are set back more than 25
meters from the shoreline or because they have dispersed plumes.
Key Conclusions;
1. There has been no laboratory or field documentation of the false
negative rate.
2. There has been no laboratory documentation of the false positive
rate.
3. Limited information from field surveys implies a false positive
rate of greater than 30%.
4. There are serious questions as to whether SLD plumes are large
enough or remain distinct and intact in lakes long enough to be
detected.
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5. There appear to be many non-plume sources of fluorescence which
actuate the SLD device, causing false positives.
2.2 RECOMMENDATIONS
SLD surveys should not be used in facilities planning until the false
negative rate has been established and deemed acceptable.
Because the SLD concept is intriguing, there will probably be
additional private sector research aimed at developing an accurate,
reliable, and cost effective SLD device. The following list of recommended
research efforts has been developed to this end.
.. 1. Carefully planned dye or tracer tests should be conducted in
conjunction with SLD surveys in several lake shore areas with
different geologic and soil conditions, to provide the data
necessary to establish the false negative rate.
2. Double blind laboratory experiments should be conducted under
controlled conditions to demonstrate the SLD device's, reliability
and repeatability. Table 2 presents an example experimental
design.
3. A set of SLD survey procedures should be developed and tested.
This would provide a much higher degree of standardization for one-
time studies of a single lake, multiple studies of the same lake
over time, and one-time and multiple studies of several lakes.
4. Experiments .should be conducted in the field to determine the true
impact of environmental conditions on the accuracy of SLD survey
results. This could be done at the same location and time as the
tracer dye tests suggested in No. 1 above. A field survey of a
shoreline along which all septic systems are marked by a tracer
would provide information on false negative as well as false
positive rates. This type of test would also provide interesting
insights into the role of the visual shoreline inspection in the
SLD device's ability to identify septic tank leachate plumes.
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TABLE 2 ..DOUBLE BilND
CONTROLLED CONDITIONS EXPERIMENT
FOR
SEPTIC LEACHATE DETECTION (SLD) ACCURACY
Select a number of standard water samples, ranging in contamination level from
distilled water to (possibly diluted) septic tank effluent. Example standards
might include:
distilled water
tap water
background lake water
background lake water spiked with phosphate*
background lake water spiked with nitrate
background lake water spiked with coliform
background lake water spiked with chlorides
septic tank effluent diluted with lake water 1/100
septic tank effluent diluted with lake water 1/10
*all spikes should be to concentrations equal to 1/10 the septic tank effluent
sample
Make up (a minimum of three) duplicate 15 gallon samples of each standard,
randomly numbered from 1-10.
Experimental Procedure
An operator not familiar with the experimental set up should measure each'sample
using a full scale SLD device, recording both the inorganic and organic meter
readings as well as the combined signal for each sample. Calibration can be
handled in two ways. Either the calibration can be set as part of the
experimental set up, in which case the results across operators can be compared,
or, the individual operators can be asked to calibrate the SLD device based on
initial trial measurements. In the latter case, the results across operators
will not be comparable, however the impact of different calibrations on the
results can be studied. The experiment should be conducted in both ways for the
most complete results.
Analysis -.
The results should be analyzed in several ways to determine:
o The repeatability of SLD device readings on duplicate samples for the same
operator and across operators.
o The ability of the SLD device to consistently distinguish between distilled
water, background lake water, and diluted septic tank effluent, for the same
operator, across operators, and with different calibrations.
o Which of the water quality components normally associated with domestic
wastewater (e.g., phosphates, nitrates, chlorides, or coliform) has the
greatest impact on SLD readings.
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SECTION 3
SEPTIC LEACHATE DETECTION (SLD) CONCEPT
3.1 THE SLD CONCEPT
The first step in evaluating any new theory is to express it in clear
terms. Numerous published and unpublished documents describe the SLD
concept in varying levels of detail (e.g., IEP, Inc. 1980, ENDECO 1977
and 1979: K-V Associates 1978, 1979 and 1980: WAPORA 1983.
In their description of SLD surveys (Table 1) U.S. EPA Region V
provides an excellent outline of the SLD concept:
"The operational theory of the detector depends on the
assumptions that fluorescent organic materials are present
in wastewaater and that inorganic chemicals will be present
in wastewater at higher concentrations than in ambient
groundwater or surface water. Detection of both increasing
fluorescence and increasing conductivity in water drawn by
pump from a shoreline provides tentative evidence of the
presence of domestic wastewater."
This SLD concept assumes that the following conditions exist.
1. Septic system effluent plumes form in the groundwater under soil
absorption systems and travel more or less intact toward lake
shores.
2. Once a septic system leachate plume emerges into a lake, it
remains intact for a sufficient period of time to be detected.
To be detected, the leachate plume must contain materials which
are measurable with a fluorometer, and present at detectably
higher concentrations that found in the lake water.
3.2 ASSESSMENT OF THE SEPTIC LEACHATE DETECTION (SLD) CONCEPT
In order to assess the theoretical validity of the SLD concept, the
likelihood of meeting the two conditions is analyzed below.
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Condition #1:
Plumes of septic tank effluent form in the groundwater under soil
absorption systems and travel more or less intact toward lake
shores•
The existence of groundwater plumes from septic system is consistent
with groundwater theory (Domenico, 1972) and has been documented by
researchers measuring nitrate levels (Ellis, 1983), nitrates, phosphates
and fecal coliform, (Luce and Welling, 1983), total carbon (Hirsh, 19831,
nitrate and carbon (Rea and Upchurch, 1980) and viruses (ENDECO, 1977).
Rea and Upchurch (1980) found that nitrates, phosphates, and chlorides
move in response to different factors. This phenomenon implies that
several parameters must be monitored in order to trace septic system plumes
in the ground water.
In a recently published article, Gilliom and Patmont (1983) determined
that phosphorus loadings to some lakes in the Puget Sound region are
attributed to old septic tanks. Based on statistical analysis, the loadings
are probably associated with only a few old systems located over confined
aquifers in areas where shallow perched water keeps soils persistently
saturated during the winter. This research was based on ground water
monitoring of septic leachate plumes.
On the other hand Cook, et.al., (1978) found that most septic systems
around two eutrophic lakes had clogged. The clogging caused effluent to
rise to the surface and move to the lakes as overland flow rather than
groundwater plumes.
It is also possible for groundwater to flow away from lakes and ponds
rather than toward them.
While groundwater plumes of septic leachate may exist and may flow
toward lakes, the condition is not universal.
Condition #2:
Once a septic system leachate plume emerges into a lake, it
remains intact for a sufficient period of time to be detected.
To be detectable, the plume must contain materials which are
measurable with a fluorometer and present at detectably higher
concentrations than found in the lake.
Figure 2 illustrates the optimal operating conditions for the Septic
Snooper™. The intake is held approximately one to two feet off the
lake bottom, close to the shore.. As the intake moves forward, it
intercepts the septic leachate plume.
For any plume (groundwater, storm water, or stream) to be detectable
in a larger water body, it must remain discrete and identifiable.
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Septic Leachate
Figure 2. Optimal operation procedure for an SLD device.
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Resisting dilution is particularly difficult in lake shore environment
because velocities in the littoral area of lakes are quite rapid which
causes rapid mixing. Only plumes with sufficient density, volume,
strength, and flow rate can resist dilution by mixing. Each of these
characteristics will be discussed in turn.
Density
Prentki, et al. (1979) point out that density differentials between a
plume and the lake can be very important in the degree of plume dilution.
If the plume is much denser than the lake water it will tend to sink and
be less prone to mixing. If the plume is much less dense it will rise,
forming a dispersed surface layer over the lake.
Solids content and temperature affect the density of any water
sample. Of the two factors, temperature appears to exert more of an
effect on plume density than dissolved or suspended solids content. In a
study of storm water plumes, Prentki, et al. (1979) found that a
temperature differential of only 1.1 °C caused 92% of the total density
differential between the plume and the receiving water. This was true
despite the fact that the storm water plumes contained nearly six times as
many suspended solids as the lake water. Since septic leachate plumes
should have a lower contaminant content than storm water, the importance
of temperature on the relative density of the leachate plume will be even
greater. Further, because groundwater temperatures vary less with season
than those of lake water, the relative densities of effluent plumes and
lake water may vary seasonally. Temperature variations associated with •*>
plumes were not reported in any of the SLO surveys reviewed.
Strength, Volume, and Plow
Plume strength, volume, and flow rate are all interrelated and are
dependent on the strength, volume, and flow rate of the effluent
discharged from the septic tank to the soil absorption system; the
attenuation of contaminants in the soil; and dilution of the effluent in
the groundwater as a result of both lateral and vertical dispersion.
In order to determine the likelihood of a leachate plume's having
sufficient strength, volume, and flow rate to be detectable when it
emerges into the lake, the following hypothetical analysis was developed.
The septic tank effluent characteristics used are those characteristics
recommended by EPA (1980) and found in Table 3. The analysis has been
developed using the traditional engineering worst case approach. The
conditions selected for this hypothetical example very much favor
maintenance of a distinct and identifiable plume:
o Septic tank and leach pit discharge directly into the groundwater
o No pollutant attenuation in the soil
o Leaching area of 1 meter2
o Leaching area profile to the lake of 1 meter
o Septic tank effluent flow rate of 700 liter/day
-16-
-------
TABLE 3. CHARACTERISTICS OF TYPICAL RESIDENTIAL WASTEWATER*
Parameter Mass Loading Concentration
gm/cap/day mg~71
Total Solids 115 - 170 680 - 1000
Volatile Sol Ids 65 -85 380 - 500
Suspended Solids 35-50 200 - 290
Volatile Suspended Solids 25-40 150 - 240
BOD5 35-50 200 - 290
Chemical Oxygen Demand 115 - 125 680 - 730
Total Nitrogen 6-17 35 - 100
Ammonia 1-3 6-18
Nitrites and Nitrates <1 <1
Total Phosphorus 3-5 18-29
Phosphate 1-4 6-24
Total Conforms^ - 10*0 - 10*2
Fecal Col1formsb - 10^ - 10*0
a For typical residential dwellings equipped with standard water-using
fixtures and appliances (exclud1 ng garbage dlsposals) generat1 ng
approximately 45 gpcd (170 lpcd).-J0^4_198p_)_".'
b Concentrations presented 1n organisms per liter.
17
-------
o Leach pit 15 meters from shore of lake
o Groundwater flow rate ranging from 1 to 0.2 meter/day
o Soil Porosity of 20%
o No dilution from groundwater or recharge
o No lateral or vertical dispersion of the leachate plume.
The analysis which assumes no dilution, no pollution attenuation, and
virtual direct discharge to the lake would be comparable to the situation
studied by Gilliom and Parmont (1983) where they found high phosphorus
loadings in lakes corrolated with the presence of old septic systems
located in areas with seasonally perched groundwater. While that study
documented an impact on the lake and the existence of plumes in the
groundwater, no data was collected to document whether plumes remained
intact and identifiable in the lake.
If, as in the hypothetical example, the septic tank effluent reaches
the lake at full strength, its detectability will depend on the velocity,
quantity, and cross sectional area of the plume as it enters the lake.
For a fixed quantity of wastewater, the rate of plume dilution in lake
water will be inversly propotional to the plume velocity. If the plume
enters at a high rate, it will be concentrated in a smaller area and be
more likely to remain intact and identifiable, than if it enters at a low
rate.
Another important consideration is the cross sectional area of the
plume. The larger the cross section, the greater the likelihood that the
SLD device will intersect it on a given pass of the shoreline. However,
since cross sectional area and concentration are inversely proportional,
plumes with large cross sectional area tend to be harder to detect because
they are dilute and easily mixed.
Cross sectional area is also inversely proportional to velocity.
For the fixed volume of septic tank effluent of 700 liters/day in the
hypothetical example, the higher the discharge rate into the lake the
smaller the cross sectional area and vice versa. At a relatively high
groundwater flow rate of 1 meter/day, the cross sectional area of the
plume would be 0.68 meter2. At a lower groundwater flow rate of 0.2
meter/day the cross section area would be 3.4 meter2. At these
groundwater flow rates, the discharge into the lake is very slow: .005 to
.0001 cm/sec. Even though the concentration of the plume in this worst
case example could be a 1000 times the concentration in the lake water,
the velocity and volume are very low, making the plumes very susceptable
to dilution and rapid assimilation into the lake.
Plume Fluorescence and Conductivity
The SLD concept is based on the assumption that plumes have a higher
concentration of dissolved organics and inorganics than the surrounding
lake water. The existing SLD equipment displays a relative increase or
decrease for fluorescence and conductivity, or in one machine, simply
-18-
-------
fluorescence. Since both machines rely on fluorescence, only the
specificity of that indicator is evaluated here.
The results of an analysis conducted on 35 samples "collected from
septic tanks" (Peters 1982), suggest that while septic leachate plumes may
fluoresce in the spectrum of interest, so do a number of organic materials
in lakes not necessarily of wastewater origin.
3c3 CONCLUSION
While under many geohydrological conditions, septic leachate plumes
migrate through the groundwater to lakes, the above analysis raises
questions as to whether such plumes are likely to be of sufficient
density, strength, volume, and cross sectional area to resist dilution and
be consistently identifiable with a SLD device^ Furthermore, there are
numerous "naturally" occurring phenomena that could cause localized
increases in lake water fluorescence unrelated to the presence of
effluent. These natural phenomena could trigger the SLD device response.
-19-
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SECTION 4
EVALUATION OF SEPTIC LEACHATE DETECTION (SLD)
4.1 INTRODUCTION
Although the total number of SLD surveys conducted between 1976 and the
present is not known, it.is estimated to be fewer than fifty. Septic
Leachate Detection (SLD) Surveys have been conducted throughout the country
in a variety of locations from Massachusetts to Washington state. Fifteen
SLD surveys listed in Table 4 were reviewed for this study.
To date, SLD surveys have consisted of two components: a visual
inspection of the shoreline and a real time measurement of conductivity
and/or fluorescence using a SLD device. Since visual inspection and
monitoring are used interactively, it is impossible to completely separate
them. For example, SLD device readings indicating potential plumes may
cause a surveyor to make a more careful inspection of the shoreline for
possible pollution sources. Similarly, upon observing a potential
contamination source, the surveyor may make several passes with the SLD
device in an effort to locate plumes.
The visual shoreline survey is an accepted wastewater planning tool in
lake areas, comparable to a windshield survey used on the land. It is the
use of the SLD device which differentiates a SLD survey from traditional
methods. This evaluation will focus on whether the use of an SLD device as
a screening tool improves the information gained from a shoreline survey
(Section 4.2), the value of information gained in a SLD survey relative to
that gained using other traditional or non-traditional methods (Section
4.3), and the relative costs of SLD surveys (Section 4.4) as compared to
traditional survey techniques.
4.2 ACCURACY
There are two components to the accuracy of SLD surveys: the number of
normal systems mistaken for failures, and the number of failing systems
missed. The false positive rate is the ratio of apparent plumes detected by
the SLD device which turn out to be indistinguishable from ambient water
quality when sampled, to the total number of plumes identified. The false
negative rate is the ratio of true plumes which are missed to the total
number of plumes identified.
In general, false positives are caused by the presence of phenomena
mimicking the characteristics of the phenomena being measured. False
-20-
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negatives occur when the device being used is measuring the wrong
characteristics or when conditions exist which hide or mask the
characteristics of the phenomena being measured. Based on extensive field
experience with SLD surveys, U.S. EPA Region V has developed a list of
situations which cause both false positives and negatives. These were
presented in Table 1.
Since the possible causes of false positives and negatives in a SLD
survey differ, the two rates are not necessarily related. A high false
positive rate does not necessarily imply a low false negative rate or vice
versa. A device which does not measure its goal can easily have both a high
false positive and a high false negative rate. In evaluating the accuracy
of any measuring device, it is important to document both the false positive
and negative rates independently.
When a SLD device is used to screen a lake for possible contamination
sources, the impact of false positives is financial not environmental.
False positives must be confirmed or'rejected based on laboratory analysis
of water collected from the possible plume. The higher the false positive
rate, the more laboratory work is required, and the greater the SLD survey
will cost. If the false positive rate is too high, the economic viability
of the technique may be in question. However, the SLD survey approach could
still be quite valuable even with a fairly high false positive rate.
The impact of false negatives in a SLD survey are environmental rather
than financial. No extra costs are incurred, because the device does not
identify any possible plumes to be sampled. However, adverse environmental
impacts are possible .if the SLD device fails to detect existing plumes
entering the lake and water quality planners base treatment decisions on
this erroneous information. This environmental impact makes a high false
negative rate incompatible with the objectives of SLD surveys.
The SLD literature and survey reports were reviewed for information
which could be used to document false positive and false negative rates
under both controlled and field conditions.
SLD Accuracy under Controlled Conditions
While no method of measurement is perfect, certain accepted methods of
measurement have been tested to determine how closely results reflect actual
values. The three criteria most often used to evaluate measurement methods
in water and wastewater are:
o Limits of Detection, which define the ranges of concentrations for
which the method works
o Standard Deviation which defines the anticipated level of precision
(that is, the difference between the measured value and the true
value)
o Standard Error, which describes the method's accuracy (that is,
does it measure the right phenomena).
-21-
-------
These characteristics are defined in the laboratory under controlled
conditions by repeated measurements of samples of known concentration. The
user can then apply this understanding of a measurement method's limitations
when interpreting field data.
There are no laboratory data defining the limits of detection, standard
deviation or standard error of SLD devices in the published or unpublished
literature identified and reviewed as part of this present study. A series
of experiments documenting these key measurement method evaluation criteria
should be conducted prior to field use of any measurement device. The lack
of such experiments seriously limits the trustworthiness of data collected
in the field.
SLD Accuracy Under Field Conditions
Sources of Data on SLD Device Performance; Reports of the IS SLD
surveys listed in Table 4 were reviewed for evidence that would substantiate
the accuracy of SLD device readings in the field. The results of water
quality analyses performed in conjunction with SLD surveys were presented in
seven of the reports. In all cases, water quality analyses of
non-contaminated or background samples were also reported. The data, as
originally reported, are included in Appendix A as Tables A-l to A-12.
In general, the water quality analyses presented in the seven SLD
survey reports were performed on two categories of water samples:
background and effluent plume. The background samples were collected in
areas which were considered by the SLD survey team to be representative of
the non-contaminated areas of the lake. Background surface water samples
were collected either in the center of the lake or in areas along the shore
line where SLD device readings indicated background water quality.
Background groundwater samples were collected from areas considered by the
SLD survey team to be free from the influence of septic effluent plumes.
The seven reports contain information on data collected at a total of
nine lakes, two of which were monitored on two separate occasions, for a
total of 11 data sets. Because the SLD surveys reviewed for this analysis
were performed by a number of independent SLD teams over a period of time,
there is considerable variation -in the water quality parameters reported.
The results frequently indicated concentration levels below the detection
level of the laboratory tests. This analysis will focus on the parameters
for which there were significant results.
In eight of the 11 data sets, values for either conductivity or total
dissolved solids (TDS) were reported. In a different subset of eight data
sets, levels of either total phosphorus (P) or phosphate-phosphorus
(PC>4-P) were reported. While all of the studies reported some measure of
nitrogen (N) content of the water samples, there was not a concensus as to
which nitrogen form provided the best measure of contamination. Five
different forms of nitrogen were measured, Total N, Kjeldahl-N, NH3-N,
N03-N, and N03+N02-N. Sodium, chlorides, total and fecal coliform
were also reported.
-22-
-------
Limitations of the Data on SLD Device Performance; The data collected
by these independent SLD survey teams were not intended for use in a
statistical analysis of the accuracy of SLD device readings. They therefore
have several limitations when viewed in this new context:
1. In most data sets only a token number of background samples were
analyzed. Only one study included a reasonable distribution with
analysis of eight background and 19 plume samples reported. One
other study reported findings on three background samples and 19
plumes. Of the remaining nine studies, four, included analyses of
only two background samples, and five only included analyses on
one. Because of these data limitations, the statistical analyses
below were performed using special techniques designed for use with
small sample sizes. However, even these special techniques do not
compensate for the lack of data. Because of this data limitation,
the results of the statistical analysis presented later in this
section tend to favor SLD test validity. Appendix B contains a
detailed explanation of the statisticcal procedures used.
2. There are several types of errors which must be avoided when
monitoring environmental parameters. False positive errors occur
when the monitoring device indicates that contamination exists when
in fact there is none. False negative errors occur when the device
fails to identify contamination which is in fact there. Because of
the way the data have been presented in the SLD survey reports, it
is possible to make rough estimates of the rate of false positive
errors (the probability that the water quality in a "detected"
plume is in fact indistinguishable from background). However,
since none of the SLD survey teams systematically gathered samples
at shore line areas, which from visual inspection might have been
expected to have plumes but where the SLD device readings did not
indicate the existence of such plumes, it is not possible to
estimate the level of false negative errors.
Questions About SLD Performance which Can be Addressed Given Data
Limitations; A thorough examination of the performance of a SLD device
should address all of the key issues of data validation and system
performance: sensitivity, specificity, stability and reliability, zero
drift, reproducibility, precision, response time, calibration, and
accuracy. However the current analysis is restricted by the limitations
of available data to addressing two basic questions:
1. Does the SLD device distinguish between contaminated and
uncontaminated' lake water?
2. Does a SLD device reading indicating a plume in the surface water
correlate with the existence of a subsurface effluent plume in the
shallow groundwater adjacent to the lake shore?
-23-
-------
Does the SLD distinguish between contaminated and uncontaminated lake
water? To answer this question the reported data was analyzed to determine
if the concentrations of typical water quality parameters are consistently
higher in plume samples when compared to background samples for:
a. All constituents
b. Certain constituents, or
c. Particular SLD surveys.
The Student's T-test was used as a measure of whether the observed
differences between the background and plume samples were statistically
significant. As with any evaluation, a decision criterion must be set
establishing acceptable and unacceptable performance. In the case of
laboratory analysis of water quality parameters, acceptable levels of
performance have been establish-through years of standard setting and are
most often referenced in Standard Methods. (APHA, et al, 1980)
Typically, water quality monitoring equipment is expected to perform
with a signifance level of less than 1%. Because the SLD devices as
currently conceived are not meant to be quantitatively accurate, but
rather screening devices, this evaluation will use a 30% significance
level as the decision rule for what constitutes an acceptable performance
in distinguishing between a contaminated and uncontaminated water sample.
In other words, if the equipment performs satisfactorily using this test,
the user can be fairly confident that the false positive rate will be
about 30%.
Figure 3 illustrates graphically the frequency distribution for
probabilities, Pr = 1%, Pr = 39%, and Pr = 92%. The first example (Pr = 1%)
is illustrative of a data set were the concentrations in the plume sample
are consistently sufficiently higher than those in the background samples
to be considered statistically significant when the 30% decision rule is
used. The second example (Pr = 39%) illustrates a set of data where although
the mean concentration in the plume samples is still higher than those for
the background samples, the difference is not sufficiently great to be
statistically significant. The third example (Pr = 92%) illustrates a
case where the plume and background samples are so similar as to be almost
identical.
The results of this analysis are summarized in Figure 4 which presents
the results for the six data sets which had at least two or more background
samples.
A total of 31 constituent analyses were performed for these six data
sets. Of these, six (19%) had a mean value in the plumes which was less
than the mean value of the background. Nine (29%) did not meet the 30%
decision rule, while 16 (52%) met the 30% decision rule.
-24-
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TABLE 4. SLD SURVEYS REVIEWED
— Ho.
1
2
Study Title Short Title STATE PATE Contractor
Shoreline Water Quality Survey, Lake Attltash MA pet 1980 IEP. Inc.
Lake Attltasli
Investigation of Septic Squam Lake NH Sept 1977 ENDECO
Leachate Discharges Into
Squam Lake
Client DATA for Statistical
1
!
Board of Health YES
Ames bury, MA
1
Squam Lake Assn. YES
I
Subsurface Leachate Discharges
Into Johns Pond, Mashpee
Johns Pond MA Aug. 1976 Environmental Town of Mashpee
Management
Institute
YES
to
Ui
EIS - Alternative Waste Treatment
Systems for Rural Lakes Project
Case Study Number 5 Otter Tall
County Board of Commissioners,
Otter Tall County, Minnesota
FINAL
Appendix B
Septic Leachate and Groundwatcr
Flow Survey, Otter Tali Lake,
Minnesota
Ottertall
MN
Sept 1979 K-V Associates Region V EPA
YES
EIS - Alternative Waste Treatment
Systems for Rural Lakes Project
Case Study Number 1
Crystal Lake Area
Sewage Disposal Authority,
benzle County, Michigan
Appendix C
Investigation of Septic Leachate
into Crystal Lake. Michigan
Crystal Lake
MI Dec 1978 K-V Associates Region V EPA
YES
-------
TABLE 4 (continued)
No. Study Tide
Short Title STATE DATE Contractor Client DATA for Statistical
Investigation of Septic Leachate ERA Study
Discharges into take Wlnona, Lake
Wlnnepesauliee (and) Ossipee lake
NU
Oct 1977 ENUECO
Estimation Research
Associates, Inc.
YES
10
EIS - Alternative Waste Treatment Steuben Lake
Systems for Rural Lakes Projects
Case Study Number 4
Steuben Lakes Regional Waste District
FINAL
Appendix D
Septic Leachate and Croundwater
Flow Survey, Steuben Lakes,
Indiana
IN Aug. 1979 K-V Associates Region V EPA
Investigation of Septic Leachate Carver County
entering Six Lakes In Carver
County, Minnesota
HN June 1980 Swanson Ellison - Phllstroo
Environmental Ayers, Inc.
Inc.
YES I
8
Septic Leachate
Lake Boon
Detection Study Lake Boon HA Aug. 1979 ENDECO
Estimation Research NO
Associates, Inc.
1
NO
10 Septic Leachate Survey
Detroit Lakes, Minnesota
Detroit Lakes MN Sept 1980 K-V Associates Rleke, Carroll
Muller, Inc.
NO
11 EIS - Case Study Number 3
Springvale - Bear Creek Sewage
Disposal Authority,
Emmet County, Michigan
FINAL
Springvale
MI
Nov. 1978 K-V Associates Region V - EPA
NO
12 EIS - Case Study Number 2
Green Lake Sanitary Sewer &
Water District, Kandiyolil
County, Minnesota
Green Lake
MN
Mar. 1979 K-V Associates Region V - EPA
NO
-------
TABLE 4 (continued)
10
No.
13
14
IS
Study Title
Thtirston County Lakes:
Uater Quality Analysis and
Restoration Plan, 1982
Lemon Lake Diagnostic Feasibility
Study, Draft Report »,
Cedar Lake Restoration
Feasibility Study
Short Title
Long Lake
Patterson Lake
Lemon Lake
Cedar Lake:
STATE DATE Contractor
UA Sept 1981 K-V Associates
IN Hay 1983 University of
Indiana
IN Dec 1982 University of
Indiana
Client DATA for Statistical
1
ENTRANCO Engineers No
No
Indiana Clean Lakes No
Coordinator
-------
CO
CO
a)
Background
• ••
I ..»
CONCENTRATION,
b)
Plum*
Background
O 20 40
CONCENTRATION
60
Pr=39%
30
100
O
CO
CO
i
Plu
Background
I .
20 40
Pr=92%
60
30
100
CONCENTRATION
Figure 3. Sample frequency distributions and probabilities of
significant differences using the student T-test.
28
-------
Survey
Uke Attitaah
P.
2"
o o
L«ke Act It ash
John* Pond
Otter Tail lake
Crvital lake
BRA (May)
BRA (August)
3t euhen/Crookad
Sceulien/JioaMson
Steuben/JaaMa
Squaa (June)
Squaa (Sepc.)
X Unacceptable Lavel of Falae Poaltivee 9
f JBackground Concentration Higher than Pluaea 6
•I Acceptable Level of Palae Positive. 16
Figure 4. Results of student T-test using 30% decision rule and omitting
surveys with only one background sample.
29
-------
When the data from the surveys with only one background sample is
included, the overall results are only slightly better. As shown in Figure
5, there were a total of 60 constituent samples/ of which nine (15%) were
negative, 14 (23%) did not meet the decision rule, and 37 (61%) met the
30% decision rule.
Does a SLD Device Reading Indicating a Plume in the Surface Water
Corrolate with the Existence of a Subsurface Effluent Plume in the Shallow
Groundwater Adjacent to the Lake Shore? Shallow groundwater samples were
collected during only two of the SLD surveys, and for one of these there was
only a single background sample. The data were analyzed using the same
Student's T-test approach used above. The results are summarized in Figure
6. As with the surface water analyses, there is very little consistency in
the results and in only 50% of cases was the difference between the back-
ground and plume water quality statistically significant.
In conclusion, there is no laboratory data reported in the literature
on false positive or false negative rates. The eleven data sets analyzed
indicate that field experience with the SLD surveys does not support the
hypothesis that the false positive rate is consistently 30% or less. There
are no data available to document false negative rates.
4.3 COMPARISON TO OTHER METHODS
A new data collection method should become widely used only if it can:
(a) Gather useful data not generated by other methods
(b) Gather similar data in a much improved level of detail, or
(c) Gather similar data at a much lower cost than other methods.
This section will consider experience with SLD surveys, based on the first
two of these criteria. The cost criteria is addressed in the following
section.
In 1979, Peters and Krause (1980) arrayed different data collection
methods used in the Rural Lakes Project, presented in Table 5, which compares
seven methods for performance under seven criteria.
A review of this matrix reveals that SLD is a very specialized data
collection method. It is meant to screen for a single factor in lake areas:
the location of septic leachate plumes. Since most direct discharges to a
lake can be identified through a visual inspection of the shoreline, the
real asset of an SLD survey should be identification of septic tank leachate
plumes entering a lake via groundwater seepage. As the matrix in Table 5
points out, this information cannot be confirmed through well sampling or
non-traditional, aerial photographic methods. Such data could be collected
using dye or tracer studies, although at a considerable expense.
The SLD survey is conceived as a method of screening a lake to
determine where to conduct more detailed sanitary surveys and lake water
-30-
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X Unacceptable Level of False Positives 14
f jBackground Concancraclon Higher Chan Pluaes 9
••. Acceptable Level of False Positives 37
Figure 5. Results of student T-test using 30% decision rule using
all survey data.
31
-------
Survey
Ottar Tail Lake
S-
^
>
««
4*
3
1
3
I
C)
1
f
8
i-4
3
S
S
^
I
Crystal L*k«
X Un«cc«pt«M« Uvel of F«l«e Positive* 2
BKkground Cooc«ntr«tlon Higher ttwn PluM» 3
BKkground Cooc«ntr«tlon Higher ttwn
Acceptable Uwl of FalM Positive.
Figure 6. Results of student T-test using 30% decision rule for
groundwater samples.
32:
-------
TABLE 5. INFORMATION PROVIDED BY ALTERNATIVE WASTEWATER PLANNING*
Problems Covered
u>
U)
Relative
Cost
based on
hypothetical
i.v • ,. Surface Ponding of
Septic Tank Aquifer
Method Effluent Contamination
Sanitary Survey Locate
Well Sampling Quantify
Discharge of Septic Tank
Effluent to Surface Water
Direct Via Groundwater
Locate
Nearshore
Plant
Growth
Locate
and
Identify
Other
Information
Household
backups
Occupancy
Water use
System design
lake
situation
discussed
in text)*
10,800
Public attitudes 3,000
(total and fecal
coliform and 1103)
Aerial Photography Locate
Septic Leachate
Shallow Groundwater
Flow Monitoring
Shallow Groundwater
Sampling
Locate
Locate
Locate
Identify
source
Locate Land use
Topography
Housing counts
Groundwater
flow data
for lake
nutrient
budgets
Quantify
3,000
11,800
5,000
3,100
Surface Water
Sampling
Quantify
Quantify
3,100
•Peters and Krause (1980)
-------
sampling programs. The field experience reviewed in the previous section
indicates that SLD survey screening results in a relatively high rate of
false positives which lead to extra follow-up work. More importantly,
without any documentation on false negative rates there is little confidence
that the screening process locates all possible sites where leachate plumes
enter the lake.
Mass balance analysis is an alternative approach to evaluating the
potential impact of septic tank leachate plumes on lake water quality. Mass
balance analysis of nutrient loads is often used as the basis for wastewater
facilities planning around lakes. This procedure involves first
characterizing the watershed around the lake. Next, assumptions regarding
the nutrient loading to the watershed from septic systems and other
sources. Then, nutrient attenuation in the soil is estimated with the worst
case being no attenuation. Using these assumptions, the total- maximum
annual nutrient load to the lake can be estimated, as can the proportion of
the total load contributed by septic systems.
Unlike SLD surveys, .the mass balance approach takes into account the
total nutrient load to the lake from all septic systems in the watershed not
those right on the lake. More importantly, mass balance takes into account
the fact that nutrient loadings to lakes may have impacts, even if the
individual plumes are not distinct and identifiable.
In summary, it does not appear that SLD surveys provide more accuracte
information than traditional mass balance analysis.
4.4 COST
The cost reports by Peters and Krause (1980) shown in Tables are based
on a hypothetical community with characteristics summarized in Table 6.
These figures imply a cost of $45-$75 per household surveyed for a sanitary
survey by which a community may be able to gather the following information:
o Surface ponding of septic tank effluent
o Quantity and frequency of household back-ups
o Direct discharges to the lake
o Near shore aquatic plant growth
o Occupancy
o Water use
o System design
o Public attitudes.
For purposes of this analysis, an average cost for sanitary surveys of $60
per household was used.
The cost figures developed by Peters and Krause (1980) have been used
in the example presented in Table 7. This hypothetical example compares
the costs for a SLD survey either independently, or in conjunction with a
partial sanitary survey to the costs of a full-scale sanitary survey. The
conditions for this hypothetical example are very favorable to SLD survey,
-34-
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TABLE 6. HYPOTHETICAL EXAMPLE COMMUNITY DEVELOPED BY
PETERS AND KRAUSE (1980)
Characteristics
Development located primarily near lakeshores
600 homes
Total shoreline of 9 miles
Sanitary surveys conducted for 25-40% of residences
Surface and shallow groundwater samples taken for nutrient and
bacteriological analysis at 30 sites in the vicinity of effluent plumes
entering the lake
Shallow groundwater and surface water sampling in conjunction with the
shoreline septic leachate survey
Well water sampling in conjunction with a sanitary survey.
Estimated Costs (From Table 5)
Cost
Units
Covered
Cost/Unit
Method
SLD Survey
Lake Water Sampling
Sanitary Survey
$11,800
$3,100
$10,800
600 $19
30 $300
600(25%-40%) $54-$72, average $60
-35-
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TABLE 7. COMPARATIVE COST ANALYSIS OP
SLD SURVEYS AND SANITARY SURVEYS
This hypothetical example is based on the cost figures and hypothetical
community presented by Peters and Krause (1980). In the community of 600
households, all have septic systems within 50-75 feet of the shore.
Estimated Unit Cost: SLD Survey = $19/home
Lake Water Sampling = $103
Sanitary Survey = $60/home
Case 1; Independent SLD Survey
Assumptions;
Survey entire lake shore with surface water sampling at 5% of the homes,
at an overall cost of $25/home.
Cost;
(600 SLD surveys x $19/home) + (30 homes x $103/home) = $4,500
Case 2; SLD Survey with Partial Sanitary Survey
Assumptions;
No water samples are collected, but all detected plumes would be followed
up by a sanitary survey.
90 potential plumes are assumed.
Cost;
(600 SLD Surveys x $19/home) + (90 sanitary surveys x $60/home) = $16,800
Case 3; Full Scale Sanitary Survey
Assumptions;
If SLD is not used, engineers will use professional judgement to select
appropriate 40%: of households to be surveyed.
Cost;
600 homes x 40% x $60/home = $14,400
-36-
-------
because all 600 households have septic systems within 50-75 feet of the
shore. Yet even in this favorable example, SLD survey costs are not
significantly less than costs for a full scale sanitary survey.
4.5 CONCLUSIONS
There has been neither field nor laboratory documentation of SLD survey
false positive or negative rates. Analysis of field data indicated that the
SLO has not consistently performed at a false positive rate of 30% or less
in identifying samples which are distinguishable from background due to
elevated levels of various water quality parameters.
Because of the possible adverse environmental impact of missing an
existing pollution source, documentation of the SLD false negative rate is
essential. The false negative rate is independent of the false positive
rate and must be documented separately. Until the false negative rate is
documented and can be judged acceptable, the accuracy of SLD survey data
must be considered suspect.
The data developed by a SLD survey is limited to homes within a short
distance of the lake. Further, the SLD survey concept is based on the
assumption that identifying only those septic leachate plumes that remain
intact and identifiable in lake water is important. This assumption implies
that the nutrient load from intact plumes is in some way more harmful to the
lake than nutrient loads from septic leachate plume which, for whatever
reason, have become too dilute to identify. In terms of long term ambient
water quality protection, the location of identifiable plumes is less
important than the overall nutrient load.
There is little or no cost incentive for using an SLD survey rather
than a sanitary survey. Especially when one considers the many different
types of information gathered in a sanitary survey compared to the single
piece of information collected in an SLD survey.
-37-
-------
REFERENCES
IEP, Inc., Shoreline Water Quality Survey, Lake Attitash, MA Report to
the Board of Health, Amesbury, MA, Oct, 1980.
ENDECO, Investigation of Septic Leachate Discharges into Sguam Lake,
Report to Squam Lake Association, NH, Sept. 1977.
Environmental Management Institute, Subsurface Leachate Discharges into
Johns Pond, Mashpee, Report to the Town of Mashpee, MA, Aug. 1976.
K-V Associates, EIS - Alternative Waste Treatment Systems for Rural
Lakes Projects, Case Study Number 5, Otter Tail County Board of
Commissioners, Otter Tail County, Minnesota, Report to EPA Region V,
Sept. 1979.
K-V Associates, EIS - Alternative Waste Treatment Systems for Rural
Lakes Projects, Case Study Number 1, Crystal Lake Area Sewage Disposal
Authority, Benzie County, MI. Report .to EPA Region V, Dec. 1978.
ENDECO, Investigation of Septic Leachate Discharges into Lake Winona,
Lake Winnepesaukee (and) Ossipee Lake, NH, Report to Estimation
Research Associates, Inc., Oct. 1977.
K-V Associates, EIS - Alternative Waste Treatment Systems for Rural
Lakes Projects, Case Study Number 4, Steuben Lakes Regional Waste
District, IN, Report to EPA Region V, Aug. 1979.
ENDECO, Septic Leachate Detection Study, Lake Boon, MA, Report to
Estimation Research Associates, Inc., Aug. 1979.
Swanson Environmental Inc., Investigation of Septic Leachate Entering
Six Lakes in Carver County, Minnesota, Report to Ellison 'Philstrom
Ayers, Inc., June 1980.
K-V Associates, Septic Leachate Survey, Detroit Lakes, Minnesota,
Report to EPA Region V, Sept. 1980.
K-V Associates, EIS - Alternative Waste Treatment Systems For Rural
Lakes Projects, Case Study Number 3, Springvale - Bear Creek Sewage
Disposal Authority, Emmet County Michigan, Springfield, MI, Report to
EPA Region V, Nov. 1978.
K-V Associates, EIS - Alternative Waste Treatment Systems for Rural
Lakes Projects Case Study Number 2, Green Lake Sanitary Sewer & Water
District, Kandiyohi County, Minnesota, Report to EPA Region V, March,
1979.
United States Patent No. 4,112,741, 'Scanning Apparatus for Septic
Effluents', Inventors: William B. Kerfoot and Edward C. Brainard, II,
September 12, 1978.
38
-------
ENDECO, Operator's Manual for Type 2100 Septic Leachate Detector
(Septic Snooper™)
WAPORA, Inc., Final-Generic Environmental Impact Statement, Wastewater
Management in Rural Lake Areas, Report to EPA Region V, January 1983.
Peters, G.O. and A.E. Krause, "Decentralized Approaches to Rural Lake
Wastewater Planning - Seven Case Studies", in McClelland, N.I. (Ed.)
Individual Onsite Wastewater Systems, Ann Arbor, MI, 1980.
Ganz, Charles R., C. Liebert, J. Schulze, and P.S. Stensby. "Removal
of Detergent Fluorescent Whitening Agents from Wastewater*, JWPCP,
September 16, 1981, pp. 2834-2849.
Peters, G.O., Septic Leachate Detector Research, Report to EPA Region
V, May 1, 1982.
Kerfoot, William B., "Septic System Leachate Surveys for Rural Lake
Communities: A Winter Survey of Otter Tail Lake, Minnesota", NSP
National Conference, p. 36., 1980.
Hendry, G.S. and A. Toth. "Some Effects of Land Use on Bacteriological
Water Quality in a Recreational Lake", Water Research, Vol. 16, pp.
105-112, 1982.
American Public Health Assn. et. al., "Fluorescence and Phosphorescence
Methods", Instrumental Methods of Analysis in Standard Methods for the
Examination of Water and Wastewater, pp. 370-391, Washington, DC, 1980.
Ganz, Charles R., F.L. Lyman, and K. Maek, "Accumulation and
Elimination Studies of Four Detergent Fluorescent Whitening Agents in
Bluegill (Lepomis macrochirus)", Environmental Science and Technology,
September 16, 1982, pp. 738-744.
Weeks, L.E., J.L. Staubly, W.A. Millsaps, and F.G. Villaume,
Bibliographical Abstracts on Evaluation of Fluorescent Whitening
Agents, 1929-1968, The American Society for Testing and Materials
Committee, D-12.15.05, Publication 507, September 16, 1981.
Davidson, A. and B.M» Milwidsky, Synthetic Detergents Sixth Edition,
John Wiley and Sons, New York, NY, 1978.
Underbill, Dwight, "Nephelometry, Fluorometry, Mercury Vapor Detector,
Atomic Absorption", Course material for Environmental Health Sciences,
264c, d. Harvard School of Public Health, 1976.
39
-------
Dobbs, Richard A., R.H. Wise, and R.B. Dean, 'The Use of Ultra-Violet
Absorbance for Monitoring the Total Organic Carbon Content of Water and
Wastewater", Water Research, Vol. 6, Pergamon Press, 1972.
American Public Health Asociation, American Water Works Association and
Water Pollution Control Federation, Standard Methods of the Examination
of Water and Wastewater, 15th edition, Washington, DC, 1980.
Anon, 'Seven Lakes Examined in EIS "Septic Snooper" Plan Will Save
Billions of Dollars", EPA Environment Midwest, June, 1979.
Anon, "Lower-Cost Lake Protection", Environmental Science and
Technology, Vol. 13, No. 8, August 1979 p. 909.
Freeze, R.A. and J.A. Cherry, "Advection Dispersion Equation for Solute
Transport in Saturated Porous Media", Groundwater, Prentice Hall, 1979.
Gilliom, R.J. and C.R. Patmont, "Lake Phosphorus Loading From Septic
Systems by Seasonally Perched Groundwater", JWPCF Vol.55, N. 10, p.
1297.
Domenico, P.A., Concepts and Models In Groundwater Hydrology, McGraw
Hill, NY, NY 1972.
Rea, R.A., and S.B. Upchurch, "Influence of Regolith Properties on
Migration of Septic Tank Effluent", Groundwater, 18, p. 118 (1980).
Cook, et. al, Effects of Diversion and Alum Applications on Two
Eutrophic Lakes, EPA-600/3-78-033, 1978.
K-V Associates, Model 15 Septic Leachate Detector Specifications, Data
Sheet 9, Palmouth, MA, 1983.
Brandes, M., "Characteristics of Effluents From Gray and Black Water
Septic Tanks", JWPCP, Nov., 1978, p. 2547.
Prentki, R.T., et al., "The Role of Submerged Weedbeds in Internal
Loading and Interception of Allochthonous materials in Lake Wingra,
Wisconsin, USA", Schweizerbart'sche Verlagsbuch Handlung, D-7000
Stuttgrart, 1979.
Otis, R.J. and W.C. Boyle, "Performance of Single Household Treatment
Units", J. Environ. Engineering Division ASCE. 102, No. EE1, p. 175,
1976.
J3PA, Qnsite Wastewater Treatment and Disposal Systems Design Manual,
EPA 625/1-80-012, 1980.
K-V Associates, Thurston County Lakes; Water Quality Analysis and
Restoration Plan, 1982, Sept. 1981.
40
-------
University of Indiana, Lemon Lake Diagnostic Feasibility Study, Draft
Report, Lemon Lake, IN, Report to Indiana Clean Lakes Coordinator, May
1983.
University of Indiana, Cedar Lake Restoration Feasibility Study, Cedar
Lake, IN, Report to Indiana Clean Lakes Coordinator, Dec. 1982.
Ellis, B.C., 'Nitrate Contamination of Groundwater on the Old Mission
Peninsula: Contribution of Land Reshaping and Septic Drainfields,"
NTIS PB83-108340 (1983).
Luce, H.D., and Welling, T.G., "Movement of Nitrates, Phospates, and
Fecal Coliform Bacteria from Disposal Systems Installed in Selected
Connecticut Soils." NTIS PBS3-219808 (1983).
Hirsh, M.S., "Variability in Total Organic Carbon Within a Septic Tank
System". In "1982 Southeastern On-site Sewage Treatment Conference."
N.C. Div. of Health Serv., Raleigh, N.C. (1983);
41
-------
Appendix A
FIELD EXPERIENCE DATA AND ANALYSIS
-------
Table A-l .
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Attitash Lake Report)
DWPC
e * * * •
Total * Fecal Fecal
(Station) Collfonn Col 1 form Strep
20 10
120 -10
3800 1500
180 110
360 180
300 140
300 140
80 40
2400 800
3000 1400
240 40
<20 10
80 30
50
-------
Table A-2
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Johns Pond Report)
Analyses of Water Receiving Groundwater Discharges from Domestic
Septic Units, Natural Bogs, or Inflows to Johns Pond, Mashpee
Station Volume
Ranking
5 13
10 17
12 19
14 22
16 23
18 19
19c 9
28 24
32 7
42 21
42a 3
51 10
52 4
53 5
58 12
72 2
88 8
89 16
92 15
109 (Moody Pd.)
112a
112b
112c
112d
112e
118 11
119 6
120 20
125 14
Muddy Pond
Coliform
Count*
1/100 ml
20
900
200
1800
10
neg.
90
Nutrient Content (mg/1)
P04-P N03+M02-N NH4-N
10
20
neg.
.003
.002
.001
.010
.003
.002
.001
.004
.000
.010
.002
.001
.001
.002
.002
.002
.004
.002
.002
.000
.001
.001
.002
.006
.001
.007
.002
.000
.003
.009
.012
.002
.163
.000
.006
.074
.001
.003
.003
.355
.008
.001
.002
.001
.002
.007
.049
.003
.002
.194
.020
.050
.249
.305
.079
.017
.015
.006
.054
.007
.0042
.0095
.0195
.0032
.0074
.0192
.001
.0099
.0112
.0342
.0181
.002
.004
.002
.009
.0277
.0394
.0049
.0134
.0251
.002
.001
.002
.043
.003
.0760
.0141
.0141
.0132
.088
Background Levels (Mean)
North Pond (Deep Station)
South Pond (Deep Station)
.001
.001
.002
.002
.006
.003
+8acteria1 analyses performed by Tim Hennigan Engineering, Inc. for the
Town of Mashpee Public Health Department.
*Chenrical analysis following EPA "Methods for Chemical Analysis of Water
and Wastes," U.S. Environmental Protection Agency, Washington, 0. C.
A-2
-------
Table A-3
WATER QUALITY GRAB SAMPLE ANALYSIS LOCATIONS
(as presented in Otter Tail Lake Report)
to
• ERUPTING CROUNDWATEH PLUME
O DORMANT CROUNDWATER PIDME
• ERUPTING STREAM SOURCE PIJUME
ODORMANT STREAM SOURCE PLUME
-------
Table A-5
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Otter Tail Lake Report)
Sample*
Number
1S-B
1G-B
2S
2G
3S
3G
4S
4G
5S
6S
7S
7G
88
8G
9S
10S
10G
11S
11G
12S
12G
13S
14S-B
14G-B
15S
15G
14S-B
16G-B
17S
17G
18S
18G
19S
19G
Conductivity
320
430
340
510
340
620
325
640
590
-
340
525
340
475
320
330
855
320
400
325
490
400
325
920
340
585
325
560
340
600
150
480
325
570
TDS
ppm
194
285
218
299
204
413
171
419
365
223
190
323
193
300
193
230
550
195
242
197
339
256
181
500
185
322
171
322
198
381
199
309
191
351
NO2-N N03-N
ppm ppni
<.01 .02
<.01 3.38
.01 .01
<.01 .01
<.01 .02
<.01 .03
<.01 .01
<.01 .04
<.01 .01
<.01 .02
<.01 .07
<.01 .01
<.01 .12
<.01 7.18
<.01 .05
<.01 .03
<.01 .04
<.01 .04
<.01 <.01
<.01 .04
<.01 .03
<.01 .02
<.01 .06
<.01 .02
.01 .08
<.01 .03
<.01 .02
<.01 .01
<.01 .02
<.01 .04
<.01 .02
<.01 .02
<.01 .02
<.01 .01
NI3-N
Ppm
<.03
<.03
.03
.15
<.03
<.03
<.03
1.19
.68
.03
<.03
.12
<.03
<.03
<.03
<.03
7.50
<.03
.28
<.03
.46
<.03
<.03
11.5
<.03
.40
<.03
.52
<.03
1.68
.06
.28
<.03
.25
Organic
N
ppm
.75
.10
.80
.35
.72
.80
.98
1.21
1.22
.74
.47
.38
' .64
.10
.98
1.30
2.00
.75
.30
.90
1.19
1.25
.88
.10
.65
.55
.62
.09
.67
1.80
.80
.68
.53
.02
C1-
ppm
3
4
4
2
4
2
4
7
7
4
3
8
4
20
3
3
4
4
4
3
4
3
4
6
4
6
3
2
4
3
4
7
4
4
Na
ppm
6.3
4.6
6.2
3.1
6.7
7.0
7.0
13
10
7.6
6.5
4.6
6.9
5.0
6.7
7.6
6.8
7.4
9.3
7.4
4.0
6.7
7.2
8.0
7.1
5.3
7.2
5.5
7.0
6.3
7.2
6.3
7.1
3.9
A-4
-------
Table A-6
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Otter Tail Lake Report)
Sample*
Number
20S
20G
21S
21G
228
22G
23S
23G
24S
24G
Conductivity
340
480
370
525
285
470
310
570
330
1620
TDS
190
281
203
299
187
292
192
337
168
667
NO2-N N03-N
ppm ppm
<.01 .02
<.01 .01
<.01 .02
<.01 .01
<.01 .02
<.01 .03
<.01 .02
-------
Table A-5
WATER QUALITY GRAB SAMPLE ANALYSIS LOCATIONS
(as presented in Crystal Lake Report)
PLUME
PLUME
•STREAM SOUflCE PLUME
A-6
-------
Table A^6
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Crystal Lake Report)
*
Nutriant analyaea of aurfaca (U) and groundwatar (Q) aaoiplaa takan in the
vicinity of uaatti.watar leacliata plunaa obaarvud on the Cryatal Laka ahorallna,
breakthrough
tiample
Number
1
2
3
4-
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
21
25
26
27
6
G
6
G
8
G
B
U
S
G
&
.G
S
S
bkgs
S
G
a
G
B
S
G
a
c
a
Q
s
Cond.
300
525
250
490
2?0
460
41O
260
315
383
410
403
365
390
385
380
600
382
438
412
384
555
416
368
450
636
390
Concentration
POji-P TP
.0008 .
.004
.0005
.01?
.021
—
.002
.003
.000
.002
.020
.022
.020
.003
.0005 .001
.008
.0005
.002
.006
.0000
.004
.008
.003
.022
.002
.001 .003
.001 :.004
.002 !.oo3
.000 .020
.004 :.O04
.006 .006
.001 '.003
.003 -.004
.011 '.024
.002 :.004
.003 .012
.002 L004
.010 '.020
.001 '.005
(ppm - wg/1)
WlirN
.004
.263
.003
.034
.004
.105
.005
.0003
.001
.000
.004
.026
.006
.004
.003
.004
.004
.004
.002
.0003
.008
3.773
.024
.056
.013
.025
.005
NO)-N
.043
.003
.011
.2??
.062
.800
.29?
.84?
.060
.224
.048
.260
.128
.084
.060
.045
i.aoa
.048
.220
.020
.024
.016
.026
.083
.230
3.144
.134
Ratio
AO AP AN P N
125 .005 .23 «.5* 4*
00 .016 .28 .8* 6*
60 .025 1.06. 2* 35*
i.
*
20O .016 l.?8 .4* 18*
38 .002 .10 .3* 10*
155 .020 3.76 .?* 40*
236 .02 3.11 .4* 21*
-------
Table A-6 (continued)
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Crystal Lake Report)
Sample
Number
2a
29
30
31
32
35
3'»
35
36
3?
3a
39
40
4i
42
'i 3
'Hi
'•5
S
Q
S
G
a
G
S
G
S
S
&
S
£
Go mi .
430
610
420
610
420
490
400
430
360
3?a
403
420
40O
lost in
&
&
S
S
410
3615
420
2'/0
Concentration
tOn-P TP
.002
..043
.002
,007
.002
.009
.002
.004
.004
.003
.002
.002
.003
transit
-
_
_
-
.005
.057
.003
.010
.003
.012
.004
.Oil
.011
.004
.004
.004
.004
.607
.012
.024
.025
(ppm - me/1)
MIIjt-N NOj-N
.008
.020
.010
.012
.013
.125
.0?8
.069
.032
.01 4
.009
.005
.006
.287
.404
.167
.246
.194
.950
.171
1.523
.111
.029
.046
.011
1.385
.056
.391
.436
.564
-
-
-
-
Ratio
AC AP AN P
210 .05> .97 1.4*
210 .006 1.52 .29
«
90 .008 .122 .1%
30 .006 .05 1*
Breakthrough
N
9.?*
14.5*
3#
3%
Background concentration
400
Local effluent
.004
.003
.030
+400 +6
+20
-------
:VO
Table A-7
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in ERA Study)
Analysis of Water Sample Taken at Moultonborough Bay. Hay 26. 1977.
Septic Leachate Detector Peaks.
Nitrate and
Nitrite-Nitrogen
(NOi f N02) - N
Inorganic Total
Phosphate-Phosphorus Phosphorus
Station (P04-P) in ppm (P) in ppm
in opm
Ammonia-Nitrogen
(NH4-M) in ppm
Specific Conductance
in micro mhos
(Background 1)
(Background 2)
48
53
56
61
63
65
65A
75
76
768
84
.00
.0006 *
.00
.0019
.0006
.0019
.0022
.0016
.0006
.0009
.0078
.0019
• .0009
.0016
.0028
.0034
.0053
.0056
.0056
.0059
.0037
.0034
.0031
.0233
.0062
.0078
.0036
.0213
.0133
.0102
.0126
.0069
.0144
.0087
.0109
.0119
.0127
.0120
.0223 '
.0045
.0080
.0049
.0099
.007
.0060
.0048
.0027
.0042
.0060
.0084
.0057
.0043 .
.32.2
42.2
41.0
39.4
40.2
40.9
41.8
41.9
37.6
36.0
38.2
42.8
37.9
-------
Table A-8
WATER QUALITY GRAB SAMPLE ANALYSIS
MOULTONBOROUGH BAY WATER SAMPLES. AUGUST 24. 1977.
Concentrations are* given in milligrams per -liter (mg/l-ppm),
except with Conductance. Septic Leachate Detector Peaks. -
Total
Orthophosphate Phosphorus
(POa-P) (TP)
Background
(landing)
Station 64
Station 65B
Station 63
Station 70
Station 73-70
Station 75
Station 76 (1)
Station 76 (2)
Station 81
Station 34
..0037
.0037
.0037
.0037
.0037
.0040
.0037
.0037
.0037
.0037
.0037
.0081
.0133
.0205
.0096
.0112
.0109
.0090
.0192
.0171
.0068
.0081
Nitrate
Nitrogen
(NOi-N)
.0035
.0032
.0032
.0029
.0029
.0034
.0043
.0028
.0036
.0158
.0041
Ammonia
Nitrogen
(NHa-N)
.0133
.0113
.0168
.0123
.0157
.0196
.0174
.0168
.0165
.0213
.0154
Conductance
umhos
40.1
46.4
44.2 '
42.4
43.5
46.4
42.7
44.6
43.6
45.0
46.5
A-10.'.
-------
t!
Table A-9
WATER QUALITY SAMPLE GRAB ANALYSIS LOCATIONS
(as shown in Stueben Lakes Report)
j
o-
f
?
plume sample
bacteria sample
erupting plume
stream
dormant plume
PLUME LOCATIONS ON STUEBEN LAKES - AUGUST
-------
Exhibit A-10
WATER QUALITY GRAB SAMPLE ANALYSIS
(as shown In Stueben Lakes Report)
Sample*
Numbers
Crooked Lake
IS
2S
2G
3S
3G
4S
5S
5G
> 6S
L 6G
10 7S
7G
Jimmerson Lake
3S
9S
9G
10S
10G
US
11G
12S
12G
13S
13G
14S
14G
TDS
PPm
343
324
717
327
744
486
444
1089
421
570
334
459
244
263
573
260
378
267
325
251
694
269
359
263
368
N02-N N03-N
PPM PPm
<.01 .01
<.01 .02
<.01 .01
<.01 .02
<.01 .05
.01 .14
.02 .67
<.01 .01
<.01 .39
<.01 .04
<.01 .02
<.01 .02
<.01 .02
<.01 .01
<.01 .07
<.01 .01
<.01 <.01
<.01 .01
<.01 <.01
<.01 .01
<.01 .01
<.01 <.01
<.01 .30
<.01 .01
<.01 .02
NH3-N
PPm
<.03
<.03
2.08
<.03
1.70
.04
.08
.18
<.03
1.78
<.03
2.75 '
<.03
<.03
22.2
<.03
1.75
<.03
<.03
<.03
10.8
< .03
.76
< .03
1.90
Organic
N
ppm
.57
.68
10.4
.72
1.90
.96
.18
1.07
.87
1.82
.68
24.4
.
.50
.74
10.3
.68
2.95
.62
.36
.60
1.20
.68
.49
.74
3.60
Cl-
PPm
76
76
133
76
183
- 95
72
336
88
66
77
75
. 30
30
6
30
12
31
2
32
22
° 30
8
28
9
Na
ppm
63
43
175
41
59
60
43
165
60
31
44
37
13
16
5
17
7
17
5
17
12
17
4
13
5
* = surface water sample; G = groundwater sample
-------
Exhibit A-10 (continued)
WATER QUALITY GRAB SAMPLE ANALYSIS
(as shown In Stueben Lakes Report)
Sample*
Numbers
James Lake
15S
16S
17S
17G
16S
18G
19S
19G
20S
20G
21S
21G
22S
22G
23S
24S
24G
25S
25G
26S
26G
27S
27G
28S
29S
30S
30G
TDS
PPm
262
270
278
555
257
273
254
408
243
353
266
289
261
468
257
304
648
259
453
328
700
259
286
286
257
264
412
N02-N
Ppm
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
<.01
.01
.04
.01
.01
.01
.01
.01
.01
.01
.01
.01
.03
N03-N
PPM
.01
.01
.02
.08
.02
.01
.01
<.01
.02
<.01
.01
.01
.02
<.01
.02
<.01
.50
.01
.01
.01
<.01
.01
.01
.01
.01
.01
.41
NH3-N
Ppm
<.03
<.03
<.03
26.0
<.03
.03
<.03
.37
<.03
<.03
<.03
.14
<.03
14.0
<.03
.05
30.0
<.03
2.30
<.03
62.0
.03
.65
<.03
<.03
<.03
<.03
Organic
N
PPM
.56
1.43
.50
2.00
.70
3.30 '
1.60
18.3
1.38
3.60
.60
15.4
.87
10.5
.37
1.35
17.5
.80
5.00
.38
68.5
1.15
3.45
1.32
1.34
1.37
1.25
Cl-
ppm
ft r «i •
32
61
31
17
. 31
27
52
23
56
3
30
3
28
26
30
30
15
31
45
49
26
57
49
56
63
67
73
Na
Ppm
18
18
17
10
17
17
17
7
18
4
17
15
15
15
18
17
14
17
26
29
18
19
17
22
18
19
6
*S = surface water sample; G = groundwater sample
-------
Table A-12
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Squam Lake Report)
Analysis of Water Samples taken at Squam Lake, June 22, 1977
Inorganic Total Nitrate-Nitrogen Specific Conductance
Phosphate-Phosphorus Phosphorus (N(>3 - N) Ammonia-Nitrogen In micro mhos
Station (PQd-P) In ppm (P) In pom in ppm (NH/i-N) In ppm per cm
Cotton Cove
Background .0003 .0053 .0008 .0024 ' -41.2
\> 20 .0008 .0071 .0013 .0020 41.1
24 .0003 .0180 .0013 .0020 38.9
36 .0005 .0065 .0013 .0024 41.0
Piper Cove
Background .0008 .0068 .0013 .0056 41.2
3 .0006 .0111 .0017 .0085 . 43.2
5 .0008 .0115 .0024 .0283 50.2
8 .0010 .0174 .0013 ,0157 46.9
8A .0090 .3519 .0389 .1898 230.0
13 .0003 10074 .0014 .0028 40.2
-------
Table A-12 (continued)
WATER QUALITY GRAB SAMPLE ANALYSIS
(as presented in Squam Lake)
Analysis of Water Samples Taken at Squam Lake. September, 14. 1977
IT1
Station
Background
7
32
39
42
Inorganic
Phosphate-Phosphorus
(PO/t-P} In ppm
Background
5
6
7
SB
r
.0025
.0009
.0028
.0028
.0025
.0022
.0028
.0022
.0028
.0025
Total
Phosphorus
(Pi In ppm
Cotton Cove
.0056
.0121
.0081
.0071
.0090
Piper Cove
.0065
.0112
.0084
.0105
.0105
Nitrate-Nitrogen
(N03-N)
in ppm
.0095
.0592
.2023
.0162
.0132
.0090
.0517
.0441
.0273
.0090
Ammonia-Nitrogen
N in ppm)
.0057
.0069
.0070
.0066
.0060
.0073
.0255
.0295
.2092
.0200
-------
Table A-13
Lake Attitash Complete Sample^
BACKGROUND
FECAL TOTAL
COLIFORM (Kj«l.) N MH3-H K03-N TOTAL P
• xlOO ppa xlOO ppa X100 ppa xlOO ppm
20
120
20
SO
SO
400
3O
10
10
10
30
10
3
3
71
304
64
77
59
83
30
26
2
190
1
2
0
3
8
6
0
430
0
1
0
70
0
0
4
540
1
6
3
4
3
3
13.0
10.0
129.0
116.8
48.8
94.2
107.8
214.8
137.8
268.2
1
2
3
4
3
6
7
8
9
10
11
12
12A
12B
13
14
15
16
17
16
19
20
21
22
3800
180
36O
300
300
80
2400
3000
240
200
400
300
400
20
60
340
20
20
20
80
20
600
1100
60
1300
110
180
140
140
40
800
1400
40
100
20
80
20
10
20
200
10
10
10
20
10
120
20
3
81
73
82
67
70
63
72
36
63
103
67
48
41
34
38
78
63
34
79
32
84
93
26
3
0
1
0
2
1
1
1
2
0
1
0
8
4
0
10
3
2
0
0
0
3
3
0
0
0
0
0
0
0
0
0
10
100
10
20
10
20
0
10
60
0
0
0
0
0
20
17
13
8
7-
3
4
3
3
9
4
4
1
3
3
4
4
1
6
2
3
3
9
133.1
333.4
1.8
23.2
63.0
17.9
-0.9
7.1
2.3
2.8
-0.9
7.0
12.0
23.0
-0.8
7.0
4.3
2.4
-0.9
7.0
A-16
-------
Table A-14
Lake Attitash Corrected Sample.
FECAL TOTAL
COLIFORN (Kjel.) N NH3-M
• xlOO pp« xlOO pp»
N03-N
X100
TOTAL P
xlOO pp»
20
20
80
30
400
30
10
10
30
10
5
s
71
64
77
39
83
30
26
2
1
2
0
3
a
6
0
0
1
0
70
0
0
4
1
6
3
4
3
3
16.7
11.3
70.7
6.3
1.7
0.6
0.3
0.6
3.7
2.3
4
3
6
7
8
9
10
11
13
14
IS
16
17
18
19
20
21
22
300
300
80
2400
3000
240
200
400
60
340
20
20
20
80
20
600
1100
60
140
140
40
800
1400
40
100
20
20
200
10
10
10
20
10
120
20
3
67
70
65
72
36
65
105
67
54
38
78
65
34
79
32
84
93
26
0
2
1
1
1
2
0
1
4
0
10
3
2
0
0
0
3
3
0
0
0
0
0
0
10
100
10
20
0
10
60
0
0
0
0
0
8
7
3
4
3
3
9
4
3
3
4
4
1
6
2
3
3
9
172.3
357.3
1.8
17.2
67.2
17.4
-0.6
19.2
2.1
2.6
0.6
22.9
11.7
26.4
1.8
17.1
4.5
2.4
0.5
7.8
-------
Table A-15
Johns Pond Surface Water Samples
BACKGROUND
SAMPLE »
NORTH POND
SOUTH POND
REAM
STDEV
PLUMES
3
10
12
14
16
18
19c
28
32
42
42a
31
52
53
38
72
88
89
92
109
112e
112d
112*
118
119
120
125
MEAN
ST86V
t
v
Pr
P04-P
xlOOO pp»
1
1
1.0
0.0
3
2
1
10
3
2
1
4
0
10
2
1
1
2
2
2
4
2
2
0
1
1
2
6
1
7
2
0
2.7
2.6
3.3
28.0
IS
N03*N02-N
xlOOO pp»
2
2
2.0
0.0
12
2
163
0
6
74
1
3
3
333
a
1
2
1
2
7
49
3
2
194
20
SO
249
303
79
17
16
6
54
36.1
97.9
3.1
26.0
IX
NH3-N
xlOOOO pp«
60
30
43.0
21.2
42
93
193
32
74
192
10
99
112
342
181
20
40
20
90
277
394
49
134
231
20
10
20
430
30
760
141
141
132
149.4
163.2
3.1
16.3
1*
A-18
-------
, Table A-16
OTTER TAIL LAKE Subsurface Water Samples
BACKGROUND
SAMPLE *
1
14
16
COND.
320
329
329
TOS
pp»
194
181
171
R03-N ORCAMIC-N
xlOO ppB xlOO pp«
2
6
2
79
88
62
Cl-
PP»
3
4
3
Ma
xlO ppa
63
72
72
PLUMES
2
3
4
6
7
8
9-
10
11
12
13
13
17
18
19
20
21
22
23
HEAM
STBEV
t
v
fv
323.3
2.9
340
340
329
340
340
320
330
320
329
400
340
340
390
329
340
370
289
330
336.7
23.1
2.3
18.9
4*
182.0
11.9
218
204
171
223
190
193
193
230
199
197
296
189
198
199
191
190
203
187
192
200.8
19.2
2.4
4.0
8*
3.3
2.3
1
2
1
2
7
12
9
3
4
4
2
8
2
2
2
2
2
2
2
3.4
2.8
Ool
3.0
93*
79.0
13.0
80
72
98
74
47
64
98
130
79
90
129
69
67
80
93
91
69
89
66
78.6
22.4
0.4
4.2
71*
3.3
0.6
4
4
4
4
3
4
3
3
4
3
3
4'
3.7
0.9
1.2
2.4
36*
69.0
9.2
62
67
70
76
69
69
67
76
74
74
67
71
70
72
71
69
66
70
70
69.6
3.8
0.2
2.4
18*
A-19
-------
Table A-17
CRYSTAL LAKE Surface Water Sample
BACKGROUND
SAHPLE * COMD. P04-P TOTAL P NH3-N M03-M
xlOOO ppa xlOOO ppm xtOOO pp« xlOOO pp»
15 388 1 4 3 60
HEAN 389.0 , 1.0 4.0 3.0 60.0
STDEV 0.0 0.0 0.0 0.0 0.0
PLUMES
1 300
3 250
S 270
7 410
9 31S
11 410
13 369
14 390
16 380
18 382
20 412
21 384
23 416
29 430
27 390
28 340
30 420
32 420
34 400
36 360
37 378
38 403
39 420
40 400
42 410
43 368
44 420
49 270
1
1
21
2
8
2
1
1
2
4
1
3
2
2
1
2
2
2
2
4
3
2
2
3
* -
3
2
22
3
4
3
2
3
3
4
3
4
4
4
9
9
3
3
4
11
4
4
4
4
607
12
24
29
4'
3
94
9
1
4
6
4
4
4
0
8
24
13
9
8
10
13
78
32
14
9
9
6
287
484
167
246
43
11
62
297
60
48
128
84
49
48
29
24
26
239
134
194
171
111
48
1389
56
391
436
964
REAM
STDEV
t
V
Pr
379.9
90.9
-1.0
27.0
•
3.1
4.1
2.9
23
2X
27.8
113.7
1.1
27.0
28*
94.9
111.9
2.9
27.0
2*
193.1
293.0
2.2
23
4*
A-20
-------
Table A-18
ERA STUDY - MAY 1977
Surface Water Samples
BACKGROUND
SAMPLE * P04-4 TOTAL P N03»M02-M NH3-H COND.
10*4 ppa 10*4 ppa 10*4 ppa 10*4 ppa xlO
1 0 16 36 49 322
2 6 28 213 80 422
REAM 3.0 22.0 124.5 62.5 372.0
STDEV 4.2 8.5 125.2 24.7 70.7
PLUMES
48 0 34 133 49 410
S3 19 S3 102 99 394
56 6 56 126 70 402
61 19 36 69 60 409
63 22 59 144 48 418
63 16 37 87 27 419
63A 6 34 109 42 376
73 9 31 119 60 360
76 78 233 127 84 382
76B 19 62 121 37 428
84 9 78 223 43 379
MEAN 18.3 66.6 123.6 38.1 397.9
STDEV 21.0 S7.1 39.3 20.3 21.4
t, 2.2 3.1 0.0 -0.3 0.6
v 10.0 10.9 1.0 1.2 1.0
Pr 6* 2* 100* « 66*
A-21
-------
Table A-19
ERA STUDY AUGUST 1977
Surface Water Samples
BACKGROUND
SAMPLE • P04-4 TOTAL P H03»M02-N NH3-N COND.
10*4 ppa 10*4 pp« 10*4 ppa 10*4 pp» 10
1 37 81 35 133 401
BEAM 37.0 81.0 33.0 133.0 401.0
STDEV 0.0 0.0 0.0 0.0 0.0
PLUMES
64 37 133 32 113 464
6SB 37 209 32 168 442
68 37 96 29 123 424
70 37 112 29 137 433
73-70 40 109 34 196 464
73 37 90 43 174 427
76 (1) 37 192 28 168 446
76 (2) 37 171 36 163 436
81 37 68 138 213 430
84 37 81 41 134 463
HEM 37.3 123.7 46.2 163.1 443.3
STDEV 0.9 48.0 39.6 29.8 13.3
t 1.0 4.0 1.2 4.3 12.3
v 9.0 9.0 9.0 9.0 9.0
Pr 33* 1* 27* ix 0*
A-22
-------
Table A-20
STUEBEN LAKES/CROOKED LAKE
Surface Water Samples
BACKGROUND
SAMPLE « TDS H03-M TOTAL M Cl Ma
ppa 10*2 ppa 10*2 pp« ppa ppa
1 343 1 57 76 43
MEAN 343.0 1.0 57.0 76.0 43.0
STDEV 0.0 0.0 0.0 0.0 0.0
PLUMES
2 324 2 '68 76 43
3 327 2 72 76 41
4 486 14 96 95 60
5 444 67 18 72 43
6 421 89 87 88 60
7 334 2 68 77 44
BEAM 389.3 29.3 68.2 80.7 48.S
STDEV 70.1 38.6 27.1 8.8 9.0
^ ..
t 1,6 3.1 1.8 2.2 2.6
» 3.0 5.0 5.0 5.0 S.O
Pr 17* 3x 14» ax 3*
A-23
-------
Table A-21
STUEBEN LAKES/JIMMERSON LAKE
Surface Water Samples
BACKGROUND
SAMPLE * TDS M03-M N 01 Na
ppa 10*2 pp« 10*2 pp« ppa pp»
8 244 2 SO 30 13
HEAM 244.0 2.0 SO.O 30.0 13.0
STDEV 0.0 0.0 0.0 0.0 0.0
PLUMES
9 263 1 74 30 16
10 260 1 68 30 17
11 267 1 62 31 17
12 231 1 60 32 17
13 269 1 68 30 17
14 263 I 74 28 IS
REAM 262.2 1.0 67.7 30.2 16.3
STDEV 6.3 0.0 3.9 1.3 0.8
t 7.0 *DIV/Ot 12.8 0.6 17.8
»• 3.0 3.0 3.0 3.0 3.0
P* 1* » 0* 33« 0»
A-24
-------
Table A-22
STUEBEN LAKES/JAMES LAKE
Surface Water Samples
BACKGROUND
SAMPLE » TDS N03-M N Cl Na
ppa 10*2 pp» 10*2 pp» pp» ppa
IS 262 'I 36 32 18
16 270 1 148 61 18
BEAM 266.0 1.0 102.0 46.5 18.0
STDEV 3.7 0.0 65.1 20.3 0.0
PLUHE3
17
18
19
20
21
22
23
24
23
26
27
28
29
278
237
234
243
266
261
237
304
239
328
239
286
237
2
2
1
2
1
2
2
1
1
1
1
1
1
SO
70
160
138
60
87
37
183
80
86
113
132
134
31
31
32
56
30
28
30
30
31
49
37
36
63
17
17
17
18
17
13
18
17
17
29
19
22
18
30 264 3 137 67 19
HEAR
STDEV
t
V
Pr
269.3
22.7
0.5
7.7
64X
1.3
0.7
3.3
13.0
IX
103.2
44.2
o.i
1.2
94X
43.6
14.6
-0.2
1.2
a
18.6
3.4
0.7
13.0
SOX
A-25
-------
Table A-23
SQUAM LAKE - June 1977
Surface Water Samples
BACKGROUND
SAHPLE • P04-P TOTAL P H03*K02-N MH3-M COMD.
SAHPLE • ^.yjp. i0»4 pp. 10-4 pp. 1CT4 pp. 10 pp.
a S3 8 24 412
I 68 13 *
3.5 60.3 10.5 40.0 412.0
3.5 10.6 3.5 22.6 0.0
FLUKES
20 8 71 13 20 411
24 3 180 13 20 389
36 5 65 13 24 410
3 6 111 17 85 432
5 3 115 24 .283 502
8 10 174 13 157 469
8A 90 3519 389 1898 23OO
l" 3 74 14 28 402
HEAI 16.6 538.6 62.0 314.4 664.4
29.8 1205.1 132.2 646.5 662.0
1.0 1.7 1.6 1.8 1.6
7.6 7.0 7.1 7.1 7.0
36X 14* 16* 12* 16*
A-26
-------
Table A-24
SQUAM LAKE - Sept 1977
Surface Water Samples
BACKGROUND
SAMPLE « P04-P TOTAL P M03»M02-H HH3-H
10*4 pp« 10A4 PP« 10*4 PP« 10"4 PP«
! 25 56 95 57
2 22 65 90 73
23.5 60.5 92.5 65.0
2.1 6.4 3.5 11.3
PLUMES
7 9 121 592 69
32 28 81 2023 70
39 28 71 162 66
42 25 90 132 60
5 (3) 28 112 517 255
g (6) 22 84 441 293
7 (S) 28 105 273 2092
SB <4> 2S 108 90 200
24.1 96.1
STOEV 6.5 17.2 631.8 694.8
t 0.2 6.5 2.9 2.0
I 6.3 4.1 7.0 7.0
ft 85* 1* 3* 9*
A-27
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Table A-25
OTTER TAIL LAKE
Groundwater Samples
BACKGROUND
SAMPLE » COW. TDS N03-N ORCANIC-N Cl- Na
ppm xlOO ppm xlOO ppm ppm xlO ppm
1 430 289 338 10 4 46
14 920 500 2 10 6 80
16 36O 322 1 9 2 33
MEAN 636.7 369.0 113.7 9.7 4.0 60.3
STDEV 253.8 114.9 194.3 0.6 2.0 17.6
PLUHES
2 510 299 1 35 2 31
3 620 413 3 80 2 70
4 640 419 4 121 7 130
7 329 323 1 38 8-46
8 479 300 718 10 20 SO
10 899 550 4 200 4 68
11 400 242 1 30 4 93
12 490 339 3 119 4 40
IS 589 322 3 59 6 53
17 600 383 4 180 3 63
18 480 309 2 68 2 63
19 970 351 1 2 4 39
20 480 281 1 19 2 30
21 529 299 3 13 4 ' 42
22 470 292 3 62 4 82
23 570 337 2 67 4 93
HEA1 949.7 341.2 47.1 68.7 5.0 62.1
STDEV 103.7 72.8 178.9 59.0 4.4 27.0
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Table A-26
CRYSTAL LAKE
Groundwater Samples
BACKGROUND
400 4 3 SO
HEAM 400.0 «DIV/Ot 4.0 3.0 60.0
STDEV 0.0 0.0 0.0 0.0 0.0
PLUHES
.-. 4 9 263 3
»
»
t i ' 2
i » -
.» . » j
s S • s s s
I i : s
S
REAM 485.2 9.4 17.4 307.5
STDEV 104.4 10.6 13.4 ^l'8
t 3.2 M/A 3.9 1.2 2.7
« 14 0 14.0 I*'0 l4
Pr 1* 1* *** "
A-29
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Appendix B
STATISTICAL METHODS
-------
APPENDIX B
STATISTICAL METHODS
The goal of the statistical analysis performed on the data presented
in Appendix A was to determine whether, based on field observations, it is
reasonable to assume that the SEPD surveys accurately and consistently
distinguished between contaminated and ambient water quality. To do this,
the difference between the mean of background observations and the mean of
plume observations were compared.
The significance of differences observed between the means was then
tested using a students t-test. This test determines the probability of
observing a difference in means as great or greater than those observed
during the SEPD surveys if there is in fact no difference. In other words,
the test determines if there is enough difference between the means, given
the precision of the measurements, to assume that the samples were actually
collected from two populations (i.e, water contaminated with septic tank
effluent vs. background lake water). The precision of the measurement of
the means is indicated by their standard errors. If the difference in the
means is not large relative to the standard errors, the probability is" high
that the data observations reported do not represent two distinct
populations, but rather are illustrative of the degree of variance ecpected
when collecting the samples from a single population. Since the SEPD
concept is based on the assumption that the concentration in the plume is
not only different from but greater than the background concentration, a
one tailed t-test has been used to estimate levels of significance.
The hypothesis and its test can be stated mathematically as follows.
Let:
X_ = the population mean of SEPD-plumes,
XG = the population mean for background water,
x^ = the corresponding tfample means, i = p, c,
n^ = the corresponding sample sizes, i m p, c,
D = X- XG, the difference in the population means,
d » K_ -
-------
Then/ we are testing the null hypothesis
H,,: D = 0
against the alternative
HI: D> 0 r
•
If we let d represent any possible estimate of D, then the significance of
our test of the null hypothesis can be written:
Pr[d^t:D = 0] = the significance level, where t is the critical
value of a normal variant for a given level of significance.
The test statistic is
d/[(sp 2/np) + (sc 2/nc)]1/2
and this is approximately distributed student t with v degrees of freedom/
v = A/B
2' 22
where A = [(s /n ) + (s /n )] and
p p c c
B. - [(s 2/n )2 (l/(n -D) + (s 2/n )2 (l/(n -1))]
p p p c c c
In general, the maximum acceptable level of significance for data of
this type is 5%. In other words, the procedure being evaluated is only
considered acceptable if the probability of false finding a difference in
pollution measurements is 5% or less, when in fact, there is no difference
(false positives).
Before presenting the results of this analysis, it is important to
point out some of its limitations. In several instances, the SEPD surveys
reported only a single background sample1. For simplicity, in these cases,
it was assumed that the reported background levels are perfect (i.e.,
standard deviation equal to zero). This over simplification assumes not
only that the sample was collected in the correct location, but that it is
a definitive representation of the water quality. Thus, any analysis which
indicates a significance level of 5% or less where this assumption has been
made, is over-optimistic.
B-2
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Appendix C
DETAILED CONCEPT QUESTIONNAIRE AND RESPONSES
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K-V ASSOCIATES, INC
ANALYTICAL SYSTB-iS
211 MAIN snisr • f.o. sox 57* • FAIMOUTH, MASSACHUSETTS SM^I
July 10, 1981
Ms. Patricia Oeese
Urban Systems Research & Engineering, Inc.
36 3oylston Street
Cambridge, .1A 02138
Re: Letters of June 10 and 15, 1981; septic snooper theory and function
Dear Pat:
1) That we were fully aware of the sales indorsation distributed by
2JTOECO;
2) That we were using a "Septic Snooper" from ENDECO daring services
offered from 1979 through 1981,
Although no of the principals in the development of the "Septic Snooper"
are at X-V Associates (V. Xerfooe and 5. Skinner , both had left ENDECO in
1973 after the directors' decision to channel business activities towards the
aarine environment^) Contact with WAPCRA, Inc allowed us to ecsloy the prototype
unit of the septic snooper at Crystal Lake, Michigan. Crystal Lake presented an
almost ideal situation for a leachate detector since residential housing and
septic system installation had been proceeding on porous sandy lake bed deposits •
with often substantial groundvater inflow rates. Subsequently, K7A paid for •
the firs: unfinished commercial "septic snooper" for use in winter surveys.
The unit was not completed and required substantial aodificatians by our
personnel ta function properly as a septic leachate detector.
unit has been the principal unit used for septic leachate detection services
during 1979 through spring 1981. In answering questions concerning the theory
aad operation of a leachata detector, we will concentrate attention to the
equipment used in the past and not with regard to any future detector units.
Please note also that SSDECO decided to sell a commercial septic leachate unit
after our initial success in survey work. The unit was tradeaarkad by SJIDtCO
a* a "Septic Snooper" and sold without consideration to any notifications
aade or used by K-7 Associates.
The sales material currently used by EMDECO makes far clearer your questions
of June 10. I had previously seen the Data Sheet No. 62 of June 21, 1977, but
C-l
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Ms. Patricia Deese
July 10, 1931
Page 2
the undated handout entitled "A Descriptive S canary of the ENDECO Type 2100
Septic-Snooper System" which I had not seen previously has clearly been con-
tinuously updated. The reference to optiaal lake levels probably refers to
papers I presented in Wisconsin and Minnesota (AURA Conference and university
of Minnesota, respectively) ia 1980 during which a representative of Svanson
Engineering was present. The reference to future property development could
refer to a Minnesota conference conducted during winter 1$80-19S1«
From my knowledge of septic leachate detector function, the claiss that
a septic snooper system application includes:
" -Assistance in determining optiaum lake levels and other facets of
in- lake management programs
-Help in planning future property development
-Identification of the direction and relative amplitude of 'grouscvater
inflows :
are not valid claias. The first tvo of these can be performed by coabir.ed
leachate detection and grouncwatar flow measurement. 3y relating the frequency
of discharges into the lake to prevailing groundwater flow patterns, and then
adjusting the lake level relative to groundwater elevation, the lake waters
can be aade to predominately discharge towards the shore (i.e., esefiltrate) or
maintain low flow rates .conducive to proper soil adsorption field functioning.
The third claia, however, has no relevance to septic leachate detection.
Although field documentation supports the relationship between a high probability
of plume discharges in rapid groundvater infiltration regions along lake
shorelines, a leachate detector cannot identify the direction and relative
amplitude of grounevater inflows — only a grouncwater flowaeter can do this.
la fact, using a leachate detector without independent groundvater flew
information caa result in serious misinterpretations of probable source and
impac ts .
I have attempted to answer your fairly extensive list of questions.
Documentation is provided to specific references, conference proceedings, or
other sources of information. Please note that vhile I aust avoid questions
of a proprietary nature, such of the information has been presented publicly.
The notation of questions refers ta your letter of June 10, 1981.
Sincerely,
William 3, Kerfoot
W3K:?hk
Enclosure
?.So A copy of a consultant's report will b« forwarded to you upon receiving
approval from the consulting fira.
Bill
C-2
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Answers to Questions Regarding Septic Leachate Detection
K-7 Associates, Inc.
Page 1
1. Theory
1.01 Yes, but with some important limitations. A septic leachate detector
detects the presence of wastewater-related organics penetrating into
lalcevaters. This may be caused by a (1) hydraulic overflow (traditional
failure) of the system and surface runoff or by (2) the oovement of a
subsurface plume of poorly-treated leachate from a soil absorption field
through porous soils into the lake through bottom sediments. If the
products of the leachfield do not flov towards the Lake body, regardless
of the condition of functioning of the septic system, the system cannot
be evaluated by a shoreline survey.
1.02 The fluorescing compounds are generally considered to be indicators of
.contamination. Previous analysis of the whiteners have sot as yet
shown a cause for concern (Ganz, et. al., 1975; Keplinger, et. al., 1975).
Some caution is needed because the class of aromatic compounds common
to fluorescence comprise some compound,.- of potential biogenic effect.
The principle contaminants of concern have been (a) pathogenic bacteria
and (b) nutrients, particularly phosphorus.
1.03 Domestic wastewaters contain a variety of compounds which fluoresce
withia the range of a septic leachate detector (excitation: 340-370 na):
a) Fluorescent whitening agents (-WA's)-sulfonated stilbene class'*
DASC - 3 3SB SNQ - 1 SK
DASC -4 NTS - 1 SOP
(Ganz, et. al., 1975 a and b;
and Gold, 1975)
b) Natural products which include:
Quinclines Tryptophan derivatives
Phenols Kynurenine
Catechols ' Aromatic aaiao acids (other)
1.04 Fluorescent whitening agents are used as common additives to most commercial
detergents and many water softeners. The commercial varieties observed
ia wastewatera often reflect the availability of brands as local
distributors. A sample of secondarily- treated effluent or equivalent
Official rVA designations which have been adopted by the AS73
"6-3"
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Answers to Questions Regarding Septic Leachate Detection
:<-V Associates, Inc.
Page 2
quality obtained at a local treatment-plant often reveals the dominant
FWA's to be anticipated ia on-site wastswater systems. The natural
produces are coomon to all septic tank - soil absorption systems receiving
huaan urine and faces.
With seasonal residences, pluses have been observed from dry veils
connected to sinks even though chemical toilets were in use.
Docuoented concentrations of FWA found in domestic eastevacer range
from .494 - .043 (Zinkemagel, 1975), .495 - .107 (Cans, et. al., 1975 a)
Natural product concentrations are aore stable than the fluorescent
agents of commercial agents.
1.05 5e« following references:
Cans, et. al., 1975 a
Ganz, et. al., 1975 b
Anders, 1975
Cold, 1975
1.06. Two principal mechanisms assist in removal of noraal fluorescing
compounds from septic systems:
1. Adsorption to solids
2. Biodegradacion (Guglielmetti, 1975; Cans, et. al., 1975 a)
1.07 Yes. In a properly functioning SAS, maintaining a suitable aerobic
environment and soil adsorption, pathogen bacteria are physically filtered
and attenuate rapidly. In addition, phosphorus is readily adsorbed by
~e or Ca based precipitation reactions.
1.08 Tvo types of commonly-encountered subsurface failures involve (1) septic
absorption systems installed in coarse sand or gravel, frangipan underlain
with fractured bedrock, solution channeled limestone or dolomite, with
high rates of groundvater flow or (2) septic absorption systems in high
groundwater conditions, organic deposits and moderate to rapid groundvater
flow conditions'.
In the ease of coarsely textured materials, wastewater aay have a
short residence time before entering groundwater and emerging at the
shoreline. 3oth filtering capacity and adsorptive area are severely limited
under such conditions.
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Answers to Questions Regarding Septic Leachata Detection
K-7 Associates, lac.
Page 3
1.09 the movement of bacteria in coarsely-textured substrates is well-documented,
particularly for dolomites and limestones. Under low redox conditions,
which retard the biodegradation of TWA's and natural fluorescent products,
phosphorus becaaes sobile as ferric (re*3) changes to the soluble
ferrous species (?e+2) (KVA, 1981).
1.10 The fluoresciog compounds undergo
1. dispersion
2. photo-oxidation
3. biodegradation
4. adsorption
Yes and so. It depends upon the texture .of the substrate, and the season.
a) With fractured bedrock, both bacteria and phosphorus behave conserva-
tively within the tiae frane of dispersion. Reduction to 1/50 of original
concentration is common. Where fine-textured sandy beaches may exist,
bacteria say be effectively removed and phosohorus absorbed through thick
(EPA, 1979)
aats of vegetation despite the continued presence of fluorescent indicators-
b) As shown with Ottertail Lake (Xerfoot, 19SO) under winter conditions,
however, phosphorus discharges occur without vegetative reaoval.
1.11 Since your statement of current scope of work is to evaluate the
Septic Snooper manufactured by Environmental Devices Corporation (iNBECO)
azd the leacbate detection services available from :<-V Associates,
the discussion of future devices is not appropriate here.
1.12 Specific conductance is used solely as a diagnostic characteristic of
vastewater effluent and sot as a contaminant. Phosphorus, sodiua,
nitrate-nitrogen and other constituents of interest in shoreline
vegetative growth assessment or drinking water quality impacts are, of
course, components of the total dissolved solids.
1.13 Refer to 1.11
1.14 Far aore to the point is the alteration of background grouadvater by
wastewater additions. la as individual residence, groundwater is with-
drawn and receives a certain amount of dissolved solids before recharge
through a properly operating SAS. The extent of dissolved solids loading
with residential usage is clearly influenced regionally depending upon
whether the area is a hardvater or sofrvater source.
- ' C-5
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Answers so Question* Regarding Septic Leachate Detection
K-7 Associates, lac.
Page 4
1.15 Your questions numbers 1.15 through 1.17 vhile understandably attempting
to define the conductivity role lead to a rather superficial treatment
of the types of groundwater reactions which occur as a result of 5AS
functioning. The assumption is aade that the design of the septic system
whether proper or not controls the characteristics of the groundwater
discharge. In reality, the condition of the leachate froa a system
. results from the chemical interaction of wastewater froo the adsorption
field with the chemical composition of the native ground-water.
Case 1: Crystal Lake, Michigan - see Kerfoot and 3'
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Answers to Questions Regarding Septic Leachate Detection
K-V Associates, Inc.
Page 5
>
1.20 I do not think I would ever aake a statement like this. Whatever is a
septic leaehate outfall - an artesian well pipe discharge?
At the saae tiae, however, the occurence of a stable ratio between
fluorescence (of correctly-identified waste products) and conductance
has been documented for:
1. Downstream profiling of outfall discharges into lakes and
rivers (Winaepesauke and Green/Nest Lakes)
2. Septic leaehate discharges in sandy shoreline soils (Crystal
Lake), particularly in low pH regions (Cape Cac).
3. Shoreline locations with substantial groundwarar inflow rates
(greater than 10 feet/day flow).
1.21 As previously aentioned (see letter introduction), I belisve the reference
can only refer to the application of a leaehate detector and a groundwater
flovaeter to determine the appropriate lake level to minimize septic
system discharges around a lake periphery. A result qui:e possibly
achievable with a dammed or iapounded lake with water level control.
1.22 This phrase is stretching the design of. ths instrument which was originally
intended for lake shoreline scanning. However, the device has been used
in closed -loop canals, low flow rivers, lake harbors, for well water
scanning, and for investigation of wastewater treataent plant discharges
into sand filter beds and directly into streacs.
1.23 A central lake water saaple constitutes the dilution water. Secondary
effluent is a convenient sample free of particulates, representing a
composite saaple of the commonly utilized local fluorescent additives
and the anticipated dissolved solids loading. The choice of secondary
effluent also emphasises the aore refractory fluorescent coapouncs
anticipated to be released from the aerobic leaching field component of
a septic tank - leaching field on-lot septic system.
The choice of 10Z is siaply based upon chart paper gridding and
field observation. The limit of detectability with a 10". solution f
scale runs to .57.. Usual lake dispersion reduces a 1007. ;roundwater
source to less than a 5% signal in the overlying water.
07
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Answers to Questions Regarding Septic Leachate Detection
K-V Associates, lac.
Page 6
1.24 Again you are asking a, leading question. A wide variety of sewage
treatment plant processes exist as well -as on-site septic systems. If
you wane to compare functioning, then consider a sevage treatment plant
with a primary anaerobic treataent system and a secondary aerobic
treatment cell to that of an anaerobic septic tank - aerobic leaching
field/unsaturated zone percolation/groundwater oc-lot system.
If a sewage treataent plant were to become completely anaerobic,
there would be a significant change in its ability to- degrade organic
compounds, but virtually no iapact on conductance. If the aerobic portion
af the on-lot system becomes anaerobic, biodegradation (oxidation) of
aromatic organic compounds is interfered with, allowing fluorescent
refractory constituents to migrate through the soil, the extent of
migration is dependent upon the prevailing groundwater condition
(pH, redox potential composition), the rate of groundwater (residence
tiae before discharge to lake).
1.25 I do not think the connection was intended, but I really am not the one
to answer the question. Calibration is noraally performed agaizst the
best local representative effluent sample. In order of priority, these
ars:
1. A solely domestic wastewater treataenc plant;
2. A composite of local domestic package plants or clustered systems;
3. A composite of local septic system effluents (obtainable at
distribution boxes, if possible).
?ail scale adjustment to 1" effluent would be very difficult considering
the normal range of signal to noise.
C-8
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Answers Co Questions Regarding Septic Leachate Detection
K-V Associates, Inc.
Page 7
2. las crumentation
2.01 Temperature correction is provided during calibration by use of the
background lake water at its aabiant temperature.
2.02 Convenience since both the fluorometric and conductance subunits
employed analog circuitry. Inappropriate to comment on K-7 Associates'
device at this time.
2.03 Generally speaking, groundwater infiltration into nearshore lot regions
will discharge within the top 3 feet of the water column. This assumption
can be verified by in situ grouncwater flow measurements.
(modified Septic TJToOTe?)
2.0u On the K-V uai'c_ circuitry for the pump source is independent of the
analytical system. Battery voltage is read froo a aeter'located on the
front of the unit. Flow rate is aore likely to be diminished by plugging of
intake screen with debris than battery fluctuation.
2.02 A long time constant is used as a buffer to separate short-tern peaks
froo slowly-changing background water masses. The vide range simply
reflects uncertainty of design vith limited field experience at that tiae.
2.06 The limit of detection of the Septic Snooper depends upon background
fluorescence, interferences, and conductance. A practical working liait
of detection is .5* of standard effluent.
2.07 A powered boat is not used in normal surveying. The boat is often
hand-pulled or pushed and serves to hold the leachate detector and operator.
The motor is solely used to go from one transect region to the next.
Turbulence from an outboard motor and vibration can provide serious
sources of error.
2.08 Originally it was thought that a rotating screen could maintain the intake
as a fixed distance from the lake bottom. Subsequent experience showed
that it only resulted in enhancing turbidity and fouling of the intake.
The idea waa abandoned.
2.09 Question unclear.
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Answers to Questions Regarding Sepeic Leachate Detection
K-7 Associates, Inc.
Page 3
3. Operational Procedures
3.01 Initial scans have been perforaed at the northern end of John's Pond,
Mashpee, HA to determine the best type of intake structure. The initial
positive displacement pusp with a vacuum hose intake was discarded for a
centripetal sump pump because the foraer caused air bubbles to fora in the
line during blockage of the intake, creating interferences on the
fluorescent and conductance chattels.
Duplicate runs with different users provided siailar profiles during
surveying of John's Pond and the north shore of Ottertail take (X7A, I960,
1931). The probe is moved back and forth over the bottom in a sweeping
notion like a metal detector at an ideal distance of 2 inches above
bottom.
Since a small vial of sample from each identified plume is required
for later analysis, professional subjective judgement is substantially
reduced.
3.02 A lot or topographical aap of suitable scale ( 1 inch = fCO feet) is
provided prior to the survey. The location of each residence is given
a number and the number transcribed on the moving tape. AS a back-check
notes are taken of the color and structure of each residence, the plume
i
location marked by a stake, and the specific fire number sr address
aarked to verify position. The specific procedure depends upon the nature
of the shoreline detail of the available aaps and type of residential
structures, but usually encorporates at least the aentioned iteas.
3.03 (1) Detailed Chemical Sampling: The Septic Snooper or the :<-V sodifiad
leachate detector are considered to be solely a locational tool. Field
chemical tests for phosphorus content, MSAS and conductance of groundwater
(plume care) samples are perforaed in.- situ. Small quantity (5 al) and
large quantity samples of the overlying water and groundwater are taken
ae each location of a plume. The small sample is analyzed by laboratory
flaorometric scanning to identify similarity to source effluent samples.
The larger voluae samples are analyzed by E?A standard procedures
(SPA, 1973) for nutrient concentration, bacterial content, and often
specific cations.
•-• --C-IO
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Answers to Questions Regarding Septic Leaehate Detection
K-V Associates, Inc.
Page 9
(2) Use of Groundwater Flowmeter: The leachate detector alone cannot
identify the direction of groundvater flov. Shoreline groundwater-laka
interactions can be complex and seasonal (Winter, 1973; Jaquet, 1976).
with 'Knowledge of groundvater flow rate
(a) The probable location of source can be identified. For instance,
a flow at 45° to the shoreline will cause a plume to emerge
on the neighbor's lot, aot where the source is.
(b) Locations of exfiltration where system-well short-circuiting
is sore likely can be identified for well vater testing.
(c) Evaluations of the vertical location of porous strata likely
to transmit effluent to the lake can be perforaed.
(3) Modifications to the Leachate Detector to Allow 2-Channel Readout
According: Fluorescence and conductance are simultaneously recorded on
a dual channel recorder system. At the sane time, a separata recorder
provides a continual analog plotting of the cojoint signal.
(4) Coordination with Sanitary Survey: Determinations of seasonal use
of septic systems are desirable when studying highly seasonal resort
areas. Type of septic system and location on lot provide useful accessory
information.
C-ll
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Answers so Questions Regarding Sepcie Leacsate Detection
K-V Associates, lac.
Page 10
4. Usefulness as a Planning Tool
4.01 Again, the information provided by the chart recording of the leachata
detector provides inforaation on the location of pluae discharge along
the shoreline. A coordinate rise of fluorescence and conductance in
the same proportion expected with local effluent identifies a probable
plume. Verification is performed by a combination of laboratory and
field analysis.
4,02 ?eaks ia conductance are usually considered nonsignificant.
Depends upon the level of confidence desired - 3" for 99", 1f for 95".
Signal to noise ratio-indicates a liait of detection of about .27. effluent.
4.03 A peak of fluorescence was found to occur without conductance with sludge
deposits or the so-called "doraant" pluses (Kerfoot and Skinner, 1981).
If spectral scanning verifies an effluent source, the location is considered
as beiag an iateraittant plume. A very similar liait of detection of
•conductance (from .1 to .2% effluent) occurs.
4.04 If both occur in the same ratio as effluent, and exhibit a spectral scan
equivalent to effluent, the plume is considered verified. However, whether
a threat of localised eutrophication or bacterial infection is likely,
can only be determined after analysis.
4.05 See Section 3.02 and 3.03*
4.06 The reporting involves (1) a lot napping of discharges and (2) a technical
report. The two types of presentation involve coding of type of discharge
involved or a projection of plume sources and strength along the shore in
addition to a technical report.
4.07 The approxiaate 5-year breakdown of funding source would yield:
SIS funds 60%
201 Construction Cranes 20%
Local/Regional Planning 10%
Private Tunds 10%.
4.03 Yes, for example see:
Crystal. Lake study
Nettle Lake study
Salem Lakes study
Lake Hopatcong study
"012
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Ansvers to Questions Regarding Septic Leachate Detection
K-7 Associates, lac.
Page 11
4.09 Additional information included by KVA: The usefulness of groundwater
flow napping and leachate surveys as a planning tool can become
an important factor in residential development surrounding grouccwater-
based lakes, planning for on-lot well water systems and 3AS systems, and
for aunicipal. well water protection. Examples of these applications can
be provided, if requested.
'013
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Answers to Questions Regarding Septic Leachate Detection
K-V Associates, lac.
Page 12
5. Cost
5.01 Usually two persona are involved in a surrey teaa. During a survey, the
ecuisnent operator rides in a boat while the field assistant directs the.
boat and is responsible for water quality analysis of identified probable
pluses. The length of tiae depends upon the shoreline length involved,
the nature of the shoreline, the detail of investigation of identified
pluses, and well sampling, if included. Generally, a field team can
average 3 to 5 shoreline ailes per day, not counting set-up or demobilization
tiae. Field studies cosmonly involve one to rwo weeks' effort for 20
shoreline aile lake areas. Analysis is usually completed within a aor.th
and report preparation within 6 weeks of thestart of field work.
5.02 Fixed cost. See enclosed price sheet for 1980. Higher costs would
result from large number of docks, convoluted shorelines, rocky shorelines
of variable water depth and difficult footing.
5.03 Yes, we currently provide operator training with the groundwater flovmeters
and intend to do so with the leachate detectors. Two days' field and
laboratory prograa ($250/cay). Consulting services are considered to
be available with any instrument purchase, if necessary.
5.04 Lease-purchase arrangements are currently available with existing equipment
anc would be planned for future equipment. Fees are negotiable, bus often
ran 5600/weeIc.
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K-V ASSOCIATES, INC. ^ 2fi I98l
ralmouth, MA
SCOPS OF WORK
1. Conduct 'a shoreline leachats survey and groundwater sapping of sections of
lake.
2. Scan the shoreline to Identify and map leachate plumes- entering the lake
from failing septic systeas, catagorizing by 3 types (surface, groundwater-
doraant, groundwater-erupting). The s'eptic leachate detector will be cal-
ibrated against local effluent from a nearby sewage treatment plant.
3. Measure the direction of groundvater flov in areas where plunes are detected
and indicate which residences the plumes appear to be originating from
(using fire number, owners name or other method) by projecting zone of con-
tributions back from position of erupting plume.
4. Using a groundwater well point sampler, vertically profile subsurface
pluses and sample core regions of suspected groundwatar pluses.
5. Do field screening of water samples for detectable levels of orthophosphate
and detergents.
6. Perform chemical analyses on field samples indicating positive results on
field screening. This will include analysis of orthophosphate, aimonia-
nitrogea conductance, and detergent (MBAS).
7. ?erfora bacterial analyses of water samples, including fecal cotifora and
fecal streptococcus, if possible.
3. Is areas where the groundwater flov pattern is avay from the lake, monitor
the direction of groundwater flov and sample groundvater beyond the septic
system to Identify possible leachate plumes flowing away from the lake.
9. The locations of septic leachate plumes and direction of groundvater flov
will be mapped.
10. Results should be summarized in table form indicating residents with salfunc-
tioning septic systems.'
•"C-15
-------
K-V ASSOCIATES, INC. Hay 26, 19
QUOTATION
Septic leachate survey and groundwater flow mapping
Total lake shoreline (20 tailes)
Residential sections only
PER
700 a£SI3ENTS FIELD RSPORT TOTAL RESIDENT
A. Field Analysis •!• Bacteria testing (1) $10,411. 52,500. $12,911. $18.44
3. Lab. Analysis + Bacteria testing (2) $12,351. $2,693. $15,044. $21.49
C. Field Analysis - No Bacteria testing (3) $ 9,600. $2,400. $L2,000. $17.14
350 RESIDENTS
A. Field Analysis + Bacteria testing $ 8,889. $1,970. $10,359. $31.03
3. Lab. Analysis + Bacteria testing $ 9,889. $2,000. $11,339. $33.97
C. Field Analysis - No Bacteria testing $ 9,390. $1,950. $11,340. $32.40
200 RESIDENTS
A. Field Analysis* Bacteria testing $ 6,700. $1,580. $ 8,280. $41.40
3. Lab. Analysis + Bacteria testing $ 6,911. $1,650. $ 8,561. $42.81
C. Field Analysis - No Bacteria testing $ 6,300. $1,500. $ 8,300. $41.50
(1) Includes vork outlined in scope of work without additional laboratory analyses
indicated in (2).
(2) Includes full range of field testing as presented in scope of vork plus lab-
oratory analysis of orthophosphorous (PO^-P) Total Phosphorus (FO^-P),
aesonia-nitrogen (NH^-N), nitrate-nitrogen (NOj-N), organic nitrogen (ORC-N),
F04-P detergent and conductance.
(3) Includes only field water quality analysis - Orthophosphate-phosphorus,
annonia-oitrogen (NH^-M) detergent, conductance; no. colifora bacteria
analysis.
C-16
-------
K-V ASSOCIATES, INC.
Hay 26, 1981
QUOTATION
Random sampling survey, Lake view Tovnship
Individual welt' supplies
Septic leachate "Short-circuiting"
BACKGROUND
Leachate from on-lot septic systems fora discrete plumes which flow dovn-
streaa with the prevailing groundwater flow. If such a plume encounters a
well intake of sufficient strength; the well is impacted and may have to be
abandoned. With a requirement of 100 foot separation between well intake and
on-lot leaching systea, the possibility of bacterial contamination in medium
sandy soils is remote. Most reported impacts originate from cheaical sources,
notably detergent, nitrate-nitrogen, or salt contamination. The expected
frequency of subsurface failure can be approximated by a probability distri-
bution. Random sampling of residents can establish the observed frequency to
allow comparison with theoretical probabilities.
1. Brief description of groundvater flow in region.
2. Selected sampling of individual well supplies.
3.. Preliminary plottiag of frequency of observed occurrences of "short-
circuiting" versus hypothetical frequency.
k. Verification of wastewater presence by fluorescent scanning-organic
analysis.
5. Cheaical analysis of water samples indicating "short-circuiting" TP,
ortho-P, NH4-N, NOyH, ?e.
SAMPLE SIZE
50 residents
20-100
100-200
300-400
ANALYTICAL
$5~06
$756
$1260
$3360
.00
.00
.00
.00
LABOR
$2000.
$3000.
$4000.
$5000.
TOTAL
$2504.
$3756.
$5260.
$8360.
COST
00
00
00
00
COST PER RESIDENT
$50
$37
$26
$20
.00
.56
.30
.90
-------
Answers to Questions Regarding Septic Leachate Detection
K-V Associates, Inc.
Page 13
6« Comparison with Other Techniques
6.1 Yes. the original Crystal Lake study involved detailed sanitary studies
of individual lots, special studies of aquatic productivity and detailed.
. investigation of individual plume sources to substantiate the accuracy
and limitations of the leachate detector (for summary, see Peters and
Kzause, 1980; for details see draft Environmental Impact Statement, Case
Study Muober 1, Crystal Lake Area, Sewage Disposal Authority, Senrie
County, Michigan). Another study of Lake Geneva and Como Lake, Wisconsin
shoved a close correlation between fecal colifora/fecal streptococcus
ratios for tributaries and the presence of wastewater discharges indicated
by the leachate detector (X'/A, 1979).
5.2 A complete survey provides the comaunity with a direct report of the extent
of existing discharges of septic-related wastewater into the lake from
along the shoreline. . It provides a means of identifying entry location,
and if suitable soil conditions exist, a means of identifying the source
of contamination for remedial action. N'o other techniques now in practice
seotic system
can readily identify and locate chemical discharges oi^origin vhich flow
through groundvater. The use of monitoring veils is impractical considering
the length of shoreline usually involved and the discrete localized nature
of pluses. The addition of commercial dyes to the septic system La
impractical due to their soil adsorption and scheduling time for sampling
for detection unless highly coarse substratum is involved.
C-18
-------
Anders, G. 1975. Limits of accuracy obtainable in che direct determination
by fluorimetry of fluorescent whitening agents ia solution. In:
Fluorescent Whitening Agents, ?. Cauls ton and ?. Xorte, eds., Georg
Thieme Publishers, Stuttgart.
EPA. 1979. Draft environmental impact statement alternative wastewater
treatment systems for rural lake projects. Case study no. 1: Crystal
Lake area sewage disposal authority, Benzie County, Michigan. Prepared
by the CS2?A, Region V, Chicago and WAPORA, Inc., Washington, O.C.
filbey, 3.. D. 1978. Mettle Lake environmental inventory and assessment, June,
1973. 21SL-LV Project RSD 7351, Office of Research and Development,
C.5. Environmental Protection Agency, Las Vegas, Nevada 39114.
Gar.z, C. X., J. Schulze, and P. S. Stensby. 1975a. Accuaulation and elimination
studies of four detergent fluorescent whitening agents in bluegill
(Lepomis aacrochirus). Envir. Sci. and Technol. 9(3):738-7uA.
Cans, C. S.., C. Liebert, J. Schulse, and P. S. Stensby. 1975b. Removal of
detergent fluorescent whitening agents from wastewater. J. WPC? 47(12):
2334-2349.
Gold, H. 1975. The chemistry of fluorescent whitening agents, sajor structural
types. In: Fluorescent Whitening Agents, ?. Coulston and ?. Korte, eds.,
Georg Thieme Publishers, Stuttgart.
Guglielaetti, L. 1975. Photochemical and biological degradation of water-
soluble rWA's. In: fluorescent Whitening Agents, ?. Coulston and F.
Korte, eds., Georg Thieae Publishers, Stuttgart,
Jaquec, X. C. 1976. Ground-water and surface-water relationships ia the glacial
province of northern Viscaosia - Snake Lake. Grouaevater, Vol. 14(4):194-199.
Keplinger, M. L., ?. L. Lymaa, and J. C. Calandra. 1975. Chronic toxic!ty and
carcinogenic!ty studies with TVA's. In: Fluorescent Whitening Agents,
?. Coulston and ?. Xorte, eds., G«org Thieae Publishers, Stuttgart.
Kerfoot, W. 3. 1980. Septic system leachate surveys for rural lake consnunities:
a winter survey cc Ottertail Lake, Minnesota. Ia: Individual Onsite
Wastevater Systems, N. I. McClelland, ed., Ann Arbor Science Publishers, lac.
Ana Arbor, MI
Kerfoot, V. 3. and S. M. Skinner, Jr. 1981. Septic leachate surveys for
lakeside sewer needs evaluation. J. W.P.C.?., Presented at Houston
Conference (1979). (In press)
K7A. 1979. Septic leachate survey, Geneva Lake and Como Lake, Wisconsin,
Soveaber, 1979. Technical report prepared for VAPORA, Inc., Chicago, IL
'C-1.9
-------
:
-------
sieanson environmental, inc.
2415S Haggertv Road
Famington Hills, Michigan 48C24
(313)478-2700
-July 7, 1981
Ms. Cynthia Ernst
Junior Analyst
Urban Systems Research &
Engineering, Inc.
36 Soylston Street
Cambridge,. MA 02138
•Dear Ms. Ernst:
Enclosed- please find our response to the Septic Snooper
questionnaire. I have answered the questions as completely
as 'possible. -
If you have any questions, please do not hesitate to con-
tact me.
Thank you for the opportunity to serve Urban Systems Re-
search & Engineering, Inc.
Very truly yours,
SWA.NSON ENVIRONMENTAL, INC.
Jill Wright
Environmental Comnliance Soecialist
/th
encl.
_C-21
-------
1.00
1.01
1.02 The fluorescing compounds are considered to be
both contaminants and indicators of contamination. The con-
taminants of concern are phosphorus, nitrogen,, and fecal
coliform.
1.03 Whiteners and surfactants.
1.04 We cannot provide documentation, although it is
available through a literature search. Our work is based
on information contained in the literature.
1.05 Same.as above.
1.06 There are Cwo main ways in which Che fluorescing
compounds are removed from the wastewacer:
Primary: phosphorus and nitrogen adhere
to Che soil parcicles.
Secondary: dilution and dispersion may occur
and, Cherefore, will not show up
in Che CesCed waCer.
Fecal coliform will not adhere
to the soil particles, but if the
distance between che SAS and Che
groundwacer and/or surface water
is great enough, the fecal coli-
form will die and, therefore, not
be evident in the waCer cesced.
1.07 Yes. Licerature search can provide documentation.
1.08 The compounds can be transmitted to the ground-
water in a number of ways.
1. In an improperly operating system, the soil
may become saturated with water so that it is
pare of che groundwacer syscem. This may occur
when che water cable is- unusually high.
2. In an overloaded system, the bottom gravel
in Che filcracion bed can become clogged 2nd che
wascewacer scream cannoc be cleansed as it goes
through. The water will then seep inco the ground-
waeer unfileered.
•"5-22
-------
3. Surface ponding may occur. The water will
flew across che surface and seep inco che grcur.d-
wacer.
The concaminancs are transmitted in the sane manner.
1.09 The compounds travel with the groundwater into
Che laka. The contaminants of concern behave in a similar
method.
1.10 Once in the surface water body, 'the fluorascing
compounds behave in Che following manner:
Organics:
surfacCanCs - disperse and become diluCed,
Chen disappear;
phosphorus and nitrogen - Caken up by the
plants and get into the system, where they
acc to increase plant life and may cause
encrophicacion of che laka.
Inorganics:
sodium and chloride - disperse inco che
syscem.
1.11 No, noc necessarily. Chlorides do noc adhere co
soil particles. They flow freely chrough che soil.
1.12 Same quescion as above.
1.13 In a properly operacing SAS, che groundwacer will
be lower in conductivicy. Literature research can provide
documentation.
1.1& Yes.
1.15 SSI has noc yec used the Sepcic Snooper in a
saline system. Statements concerning use in saline systems
are based on factory represencacion.
!-J3
-------
2.00 Instrumentation
2.01 Sol has not performed experiments Co document
consistency of temperature; temperature measurements ara
noc taken consistently; corrections are not made for vary-
ing temperature. r
2.02 SSI attempts to. travel as close to shore as pos-
sible, depending on water depth. Approximately 90% of the
time, travel is within five feet of the shore.
2.03 The power for the pump is supplied by a 12 volt
battery. Variations in the power source have very little
effect on the consistency of the water supply. The lowest
limit the battery runs on is 11-1/2 volts,"which is within
the recommended level.
2.04 I am not sure exactly how to answer this- quest-
ion. The sensitivity varies a lot. The Septic Snooper nor-
mally operates at very near maximum sensitivity levels.
It is possible to measure a change in sensitivity of
5 auohs for inorganics. This change can be consistently
detected.
2.05 In shallow water, one person either pulls or
.pushes the boat. In deeper water, either an electric trol-
ling motor is used or the boat is rowed. Because the beat
moves at less than 1/2 mph during actual scanning, beat
velcc.ity has very little effect on the flow rate.
The device is not affected by the noise of an outboard
motor, but it is affected by short wave radio. The boat
does not have a propellor, and the pump is held ahead of
the motor, so it is not affected'.
2.06 The screen on the intake device does not stabi-
lise sensitivity.
2.07 There is a 3 - - second lag in detecting con-
ductivity, and a 10 - 12 second lag in detecting organics.
Or.ce the indicators appear on the meter, the boat must go
back approximately 10"feet to detect the plume.
—C-24
-------
3.00 Operational Procedures
3.01 The sampling probe is held 6 inches to one fooc
above the bottom of Che Lake. This is necessary to avoid
drawing up soil particulates and plane debris. To che bes:
of our knowledge, tfoere have not been double blind Cescs
conducted.
3.02 The continuous graphic output is directly cor-
related Co.maps. Large scala shoreline maps are carried
on che boats, and 5El personnel make their notes directly
on che maps.
3.03 'SEI assigns che same people Co do che field sur-
vey and wrice che report. Also, SEI personnel ara trained
to follow procedures'exactly.
4.00 Usefullness as a Planning Tool.
4.01 The information on "he Cape is iacerpreced im-
mediately on site, and takes into account soil' type, topo-
graphy, and background water quality.
4.02 Peaks in fluorescence with no response in con-
ductivity are observed. In T.CSC cases this is r.oc consider-
ed to be an indicator of sepcic discharge. Claarvater dis-
charges have increased conductivity while organic levels
decline.
The least detectable signal is approximately 5 units for
conductivity and 40 - 507. above background levels for
organics.
4.03 Same as above.
4.04 Peaks in both conductivity and fluorescence usual-
ly indicate chaC septic discharge is occurring. Levels of
30 - 40% over background can be detected, but levels over
100% of backgrond ara preferred. Detectable levels can vary
depending on sensitivity.
ti-25
-------
4.05 Ocher data sources used in our studies are:
background water quality information
hydrology
. regional groundwater flow patterns
«
local groundwater flow patterns
soil types
topography
residential frequency (i.e. permanent vs.
temporary residents vs. commercial develop-
ment)
This data is used only as background information. Our
actual analysis is only of data generated from the septic
laachate survey.
4.06 SEI uses reports to transmit our analyses to our
clients. A sample Table of Contents is attached.
4.'07 Approximately 90% of our studies have been funded
by 201 Construction Grants. The other 10" have been funded
by lake associations, planning agencies, etc.
4.08 I believe that the results of cur surveys have
been used in conjunction with other studies, but SEI has
r.ot done so nor have we been informed as to the results
of such studies.
5.00 Cost
5.01 A minimum of two (2) people and a maximum of COUT
(4) are assigned to a survey team. In a eve-person team,
one person is responsible for controlling the boat and
guiding the probe. The other person keeps track of the lo-
cation, observes the equipment, directs" the person holding
the probe, and collects surface water and groundwater
samples.
"»her. necessary, two boats (4 people) go out on a survey.
The second boat collects the groundwater samples.
-------
Frequently a particular pare of the shoreline will be tra-
versed more Chan once, either immediately to locate a
plune, or at a later date to substantiate the initial re-
sults.
One (1) shoreline mile, including analysis and report, wi.ll
take approximately three days. :
5.02 Services are priced on a cost plus fixed fee
basis. Sample unit costs are attached. Conditions which
would result in higher than usual costs include heavy weed
growth and/or intense docks and cottage development.
5.03 SSI does provide operator training for clients
interested in purchasing equipment. The training" takes one
day, and the cost is incorporated into the equipment pur-
chase price. Consultation services are provided.
5.04 SEI does not rent out equipment.
6.00 Comparison With Other Techniques
6.01 Double blind tests have not been conducted.
6.02 Information gained from a complete survey
includes:
1. A very detailed, complete evaluation of the
entire shoreline area of concern.
2. An evaluation of human health related prob-
lems resulting from septic seepage.
3. -It is possible to calculate the nutrient lead-
ing and subsequent impacts of eutrophication of
the lake due to phosphorous loading, and to in-
corporate these results into a nutrient budget.
C-27
-------
SAMPLE TA3LE OF CONTENTS
I. INTRODUCTION
II. PROCEDURES
III. RESULTS
IV. CONCLUSIONS
ATTACHMENTS (detailed naps of scudy
'araa)
1-26
-------
xtra/uon environmental, inc.
CLIENT LIST
Location of Project
Lake Winnebago,
Neenah, Wisconsin
Indian Lake,
Logan County, Ohio
Lauderdale Lakes,
Walwcrth County, Wisconsin
Lake Waconia,
Carver Councy, Minnesota
Pierson's Lake,
Carver Councy, Minnesota
Lake Savaria,
Carver County, Minnesota
Re its Lake,
Carver County, Minnesota
Lake Auburn,
Carver County, Minnesota
Lake Minnewashca,
Carver County, Minnesota
Cedar Lake,
Carver County, Minnesota
Dixcn Lake,
Otsego County, Michigan
Opal Lake,
Otsego County, Michigan
Client .
Davy Engineering Company
Floyd. 3row,ne
Associates, Ltd.
Marian, Ohio
LauderdaLe Lakes
Protection Association
WaLworth County, Wis.
Ellison-PhiIstrom-
Ayers, Inc.
St. Paul, Minnesota
El1ison-Phi1strom-
Ayers, Inc.
St. Paul, Minnesota
El1ison-PhiIs t rom-
Ayers, Inc.
St.. Paul, Minnesota
Ellison-PhiIstrcm-
Ayers, Inc.
St. Paul, Minnesota
Ellison-PhiIstrsm-
Ayers, Inc.
St. Paul, Minnesota
Ellison-PhiIstrom-
Ayers, Inc.
St. Paul, Minnesota
Ellison-PhiIstrom-
Ayers, Inc.
St. Paul, Minnesota
Williams & Works
Grand P^apids, Michigan
Williams d Works
Grand Rapids, Michigan
-------
ncaruon er.cironmentai, inc.
CLIENT LIST
page 2
Location o£ Project
Clianc
Long Lake,
Ocsego Councy, Michigan
Horseshoe Lakes
Ocsego County, Michigan
Perch Lakes,
Ocsego Councy, Michigan
Hearc Lake,
Ocsego Councy, Michigan
Fawn Lake,
Ocsego Councy, Michigan
Ocsego Lake,
Ocsego Councy, Michigan
Park Lake,
Columbia Councy, Wisconsin
White and Duck Lakes,
Oakland Ccuncy, Michigan
Williams & Works
Grand Rapids, Michigan
Williams & Works
Grand Rapids, Michigan
Williams & Works
Grand Rapids, Michigan
Williams & Works
Grand Rapids, Michigan
Williams & Works
Grand Rapids, Michigan
Williams & Works
Grand Rapids, Michigan
General Engineering
Company, Inc.
?or~age, Wisconsin
Johnson 4 Andarson, Inc.
Ponciac, Michigan
C-30
-------
Appendix D
REVIEWERS COMMENTS
(All comments in this appendix have been considered and, where
appropriate, have been adopted in the final text)
-------
KENT STATE
UNIVERSITY
DEPARTMENT OF
BIOLOGICAL SCIENCES
KENT, OHIO 44242 (216)672-3613
November 9, 1983
Ms. Patricia L. Deese, P. E.
Urban Systems Research and Engineering, Inc.
2067 Massachusetts Avenue
Cambridge, Massachusetts 02140
Dear Ms. Deese:
I enclose my report on your manuscript entitled "Shoreline Surveys
of Subsurface Effluent Plumes". You have done a thorough and accurate
analysis of the current state of instrumentation for SEPD surveys.
If I can be of further service, please write or call.
Si
G. Dennis Cooke
Professor
GDC:jf
Enclosures
D-l,
-------
Evaluation of "Shoreline Surveys to Subsurface Effluent Plumes"
(Prepared by P. L. Deese, P.E.)
I find this report to be a thorough, fair, complete, and accurate evalu-
ation of the Septic Snooper. The author has raised excellent questions, tested
them with the data at hand, and formed firm conclusions and recommendations.
The following comments may be of value in preparing the final draft.
1) EPA reports have an unusual format in that Conclusions are given first.
I urge the author to develop a Discussion section at the end to review
the data and conclusions.
2) The Literature Cited section is woefully incomplete and references are
not directly cited in the test. I never did find references 1-12.
Since this is a scientific report, it should be written, as one.
3) On p. 10,, a statement is made (beginning 7 lines from the bottom) that
needs investigation. For example, I and others (Cooke et al., 1978,
EPA-600/3-78-033. Effects of diversion and alum application on two
eutrophic lakes) have reported that septic tank effluent actually moves
to the ground surface and is easily carried by overflow runoff. Leach
fields plug with organic matter, making downward percolation impossible.
4) Exhibit 4-2 is difficult to understand since the axes are not clearly
labelled and the "pr." (=probability?) values are very strange.
5) Some references:
a. Kerfoot, W. B.. and S. M. Skinner. 1981. Septic leachate surveys
for lakeside sewer needs evaluation. J. Wat. Poll. Cont. Fed.
53:1717.
b. Lee, D. R. 1972. Septic tank nutrients in groundwater entering
Lake Sallie, Minnesota. M. S. Thesis, Univ. of North Dakota (note:
Lee's thesis and subsequent papers are among the real basic works
in this area).
D-2
-------
c. Polkowski, L. B. and W. C. Boyle. 1970. Ground water quality
adjacent to septic tank-soil absorption systems. Wisconsin Dept.
of Natural Resources, Madison. 75 pp.
6) An item which was missed or not emphasized in the criticism is the impact
of macrophytes on littoral water chemistry and thus on the values reported
by the Septic Snooper. These plants are very abundant in many lakes
especially eutrophic ones, and continually senesce or slough tissue to
the water. Much of this loss of organic matter is as dissolved organic
matter (DOM), some of which may interfere. This idea is potentially an
important criticism since most groundwater discharge to the lake occurs
in this littoral zone. It may contain DOM from septic leachate which is
camouflaged by DOM from intense macrophyte senescence (early August
onwards).
7) I have noted a few typographical errors. The word "data" is always
plural.
D-3
-------
Tt
TETPA TECH, INC.
37.16 MT. DIABLO BOULEVARD
LAFAVETT6. CALIFORNIA 945*19
SUITE 3OO- 1^151/283-3771
November 2, 1983
Patricia L. Deese
Urban Systems Research & Engineering, Inc.
2067 Massachusetts Avenue
Cambridge, Massachusetts 02140
Dear Patricia:
Although your report arrived in my office on October 17, I did not return
until October 31 and consequently was unable to review the report until
now. My comments are handwritten on the document. Although considerable
editing of typos is needed, that task was not my intent. I have attached
a bill.
Sincerely yours,
Donald B. Porcella, Ph.D.
Principal Scientist
Environmental Systems Engineering
DBP/jw
Enclosure
-;.-=?
D-4
-------
1. For an average family of 4 and lOOgpcd and 24 hours of waste flow from
a leach field, the typical flow into a lake would be 0.28 gpm or 1.07
liters per minute at steady state.. In my.judgment, it would be nearly
impossible to detect consistently such a flow or chemical differences
generated by such a flow in a lake. Given a cross-sectional area of
10am 2/1 (drain = 3.6cm), this would result in a velocity of about
1.7cm/sec. changes in any of these assumptions would tend to make this
less detectable, as a rule. A good paper relating to ground water
quality and in-flow along entraphic lakes.1
2. We did some work on chemical measurements as an aid to identifying
septic inputs to a stream. The attempt was a fairline (Meyers etal).
I am convinced that although septic effluent impacts on lakes can be
substantial (Cooke et.al.), they are not measurable by such
techniques. Mass balance techniques are more useful.
3. Velocities in littoral areas of lakes are quite rapid and mixing would
occur very rapidly. Although I do not have references on this
subject, I think it would strengthen the theoretical basis for
rejecting assumption #2. Another consideration is that the data in
Appendix A on Otter Tail Lake would represent one of the most
favorable situations possible for demonstrating its effectiveness.
Most lakes are not as well situated (my assumption - ?). However,
these data do not satisfactorily support the contentionsof the vendor.
•'•Lee, D.R. 1978.. A device for increasing seepage flow in lakes
and estrainers. Linnol. Oceanogr. 22:140-147.
Note, the highly variable characteristics of the seepage inflow
in Lee's paper (p.146, Table 2).
x
2Mey4rs, D.W., E.J. Middlebrooks, & D.B. Porcella. 1972.
Effect of Land Use on Water Quality: Summit Creek, Smithfield, Utah.
PRWR 17-1. URL Utah State University, Logan, UT 84322.
Cooke, G.D., et. al., 1973. Some Aspects of Phosphorous Dynamics
of the Twin Lakes Watershed. In Modelling the Entrophication
Process. (E.J. Middlebrooks, et al Editors) Ann Arbor Press, Ann
Arbor, MI pp 57-72.
D-5
-------
University Of Notre Dame Notre Dam, Indiana 46556-0369
Department of Biology General Office (219)239-6552
25 October 1983
Dr. Patricia L. Deese
Urban Systems Research and Engineering, Inc.
2067 Massachusetts Avenue
Cambridge, MA OElUO
Dear Dr. Deese:
Enclosed please find:
1. My review of the report "Shoreline Surveys of Subsurface Effluent Plumes".
2. A reprint of a publication cited in my review.
3. The draft report, with penciled marginalia.
k. A copy of my C.V.
5. My bill for one day's consulting.
I shall look forward to hearing from you.
Sincerely,
o-t^pL^— K- C_srp^-^i^£—
Dr. Stephen R. Carpenter
Assistant Professor
D-6
-------
Review ef "Shoreline Surreys of Subsurface Effluent Flumes"
Dr. Stephen R. Carpenter
Department of Biology
University of Notre Dame
Notre Dame, IS U6556
25 October 1983
1. I am aware of no evidence that groundwater plumes cohere and remain
detectable for any distance in lakes. Storm sewer and stream inputs to
lakes may remain discrete and identifiable if their temperature is very
different from that of the lake water (Bryson and Suomi 1951, Prentki et
al. 1979). However, the volume and flow rate of these inputs are much
greater than those of groundwater, hence they are diluted mere slowly.
Ground water plumes should be less cohesive than storm sewer or stream
inputs to lakes. The integrity ef ground water plumes should depend on
the temperature differential between the ground water and lake water.
2. Many fluorescent compounds occur naturally in lake water, e.g. humic
substances and algal pigments. It is conceivable that detergents and
whitening agents could be discriminated from natural fluorescent compounds
by careful selection of excitation and monitoring wavelengths. However,
on the basis of the documents at hand I see no evidence that the background
data needed to select appropriate wavelengths have been gathered. Studies
4
comparing the fluorescent properties of sewage leachate and natural organic
matter are needed to validate the proposed methodology.
3. The proposed "unique and stable ratio" between fluorescence (F) and
conductivity (C) suggests that F/C = k, a constant, or F a kC. That is,
a plot of fluorescence versus conductivity for a population of septic
tank samples should lie on a straight lino of slope k, distinct from data
points based on lake water. It seems that the data on hand would allow
D-7
-------
-2-
one to construct such a graph and test the hypothesized relationship.
U. Based on the preceding points, I conclude that the proposed technology
is not yet validated. Further research is needed, as discussed in the
report. In particular, I suggest
(1) dye tracer studies to determine the physical integrity of
plumes of contaminated groundwater.
(ii) comparative studies of septic tank and natural organic compounds
with respect to fluorescence intensity as a function of
excitation and measurement wavelength.
5. In view of the probable importance of temperature to the integrity of
groundwater plumes, addition of a temperature sensor to the probe of
the "Snooper" is recommended.
References
Bryson, H.A. and V.E. Suemi. 1951* Midsummer renewal of oxygen within
the hypolimnion. J. Mar. He a. 10: 263-269.
Preatki, H.T., M.S. Adams, S.B. Carpenter, A. Gasith, C.S. Smith, and
P.H. Weiler. 1979* The role of submersed weedbeds in internal
loading and Interception of allochthonous materials in Lake Wiagra,
Wisconsin, U.S.A. Arch. Hydrobiol./Suppl. 57: 221-250.
D-8
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Appendix E
LIST OF PERSONS CONTACTED DURING THIS STUDY
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ALPHABETICAL LIST OF PERSONS CONTACTED
DURING THIS STUDY
Name General Question- Inter-
Address Background ' naire* view**
Roger Akeley Yes
NH Lakes Region
Planning Commission
Dan Armstrong T
George Washington University
Ron Arsenault V P
ENDECO, Marketing Manager
Bob Borpahle Yes
Elli son-Phi 1st rom-Aye r Inc.
Edward Brainard, II V P
ENDECO, President
John Dickey Yes
Rist-Prost Associates
Fred Elkind Yes
NH Water Supply/Pollution
Control
Ginny Garrison Yes
Vermont Department of
Environmental Conservation
William Kerfoot W P
K-V Associates, Inc.
Al Krause p
SPA Region V
Don LaVoie Yes
Reike, Carroll/ and Muller
Ron Manfredonia Yes
SPA Region I
James McCarthy Yes
Harvard University
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ALPHABETICAL LIST OF PERSONS CONTACTED/
DURING THIS STUDY
Nante General Question- Inter-
Address Background ' naire* view**
* W » written; V =» verbal
** P •» in person; T » by telephone
E-2;
Bill Mellen Yes
Lake County Health Dept.
I Francois M.M. Morel Yes
M.I.T.
Gerry Peters V T
WAPORA
Mike Rapacz Yes
Interdisciplinary Engineers :
|and Planners |
I ' i
JTed Rockwell ' • P !
!EPA Region V j
i
John Stewart Yes j
,Maier, Stewart and Associates j
I .
Natalie Taub Yes
EPA Region I
!
(Jill Wright . w
Swanson Environmental, Inc.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before competing)
1. REPORT NO.
3. RECIPIENT'S ACCESSION>NQ.
4. TITUS AND SUBTITLE
An Evaluation of Septic Leachate Detection
5. REPORT OATS
February 1985
S. PERFORMING ORGANIZATION CODE
7. AUTHOH(S)
Patricia L. Deese
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
Urban Systems Research and Engineering, Inc.
Cambridge, MA 02138
10. PROGRAM ELEMENT NO.
CAZB1B .
117CONTRACT7G
68-03-3057
12. SPONSORING AGENCY NAME ANO ADDRESS
Water Engineering Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT ANO PERIOD COVERED
Final (10/80 - 9/83)
14. SPONSORING AGENCY CODE
USEPA
15. SUPPLEMENTARY NOTES
Project Officers: J. F. Kreissl and R.P.G. Bowker
16. ABSTRACT
An evaluation of septic leachate detection (SLD) technology was performed.
The results indicated that the conceptual basis of SLD devices is unproven
and the devices have not been evaluated properly to determine their utility
as a screening device in facility planning for rural lakeshore communities.
Even if this issue is neglected, the cost-effectiveness of SLD surveys is
marginal.
KEY WORDS AND DOCUMENT ANALYSIS
-DESCRIPTORS
b.lOeNTIFIEHS/OPEN ENDED TERMS C. COSATI Field/Gtoup
3. OISTrtlaUTION STATEMENT
Release to Public
.19. SECURITY CLASS.(7WReport)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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