U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
NATIONAL EUTROPHICATION
SURVEY METHODS
FOR
LAKES SAMPLED IN
1972
VJ3RKING PAPER NO, 1
PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY
An Associate Laboratory of the
NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON
and
NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA
iTGPO 697.032
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NATIONAL EUTROPHICATION
SURVEY PETHODS
FOR
LAKES SAMPLED IN
1972
WORKING PAPER NO, 1
NATIONAL EUTROPHICATION SURVEY
PNERL, CORVALLIS, OR
NERC, LAS VEGAS, NV
OCTOBER, 1974
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1
TABLE OF CONTENTS
Page
Nu mber
Introduction 1
Participating Laboratories 2
Selection of Lakes 3
Field Sampling Methods 5
Lakes 5
Municipal Sewage Treatment Plants 8
Tributaries and Outlets 9
Analytical Methods 11
Nutrient Analysis 11
USGS Estimates of Stream Flows
and Drainage Areas 11
Estimates of Nutrient Loadings 13
Tributaries and Outlets 13
Municipal Sewage Treatment Plants 19
Septic Tanks 20
Precipitation 21
Algal Assay 22
Algal Enumeration and Identification 23
Quality Control 23
P NE Pr., 23
NERC-Las Vegas 24
Interlaboratory 24
Literature Cited 25
Appendix 26
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TABLES
Page
Number
TABLE 1 - National Eutrophication Survey Responsibilities 2
TABLE 2 - Number of Lakes and Start-Up Dates of
StreaiT Sampling in Northeastern States 4
TABLE 3 - Analytical Methods and Precision of
Laboratory Analyses 12
TABLE 4 - A Summary of Accuracy of Flow Estimates
and Drainage Area Measurements Provided
by U.S. Geological Survey 14
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1
INTRODU T ION
The National Eutrophication Survey (NES) was initiated in 1972 in
response to an Administration commitment to investigate the nationwide
threat of accelerated eutrophication to fresh water lakes and reservoirs.
The Survey is designed to develop, in conjunction with state environmental
agencies, information on nutrient sources, concentrations, and impact on
selected fresh water lakes as a basis for formulating comprehensive and
coordinated national, regional, and state management practices relating
to point—source discharge reduction and nonpoint—source pollution abate-
ment in lake watersheds.
Sampling was initiated in ten northeastern states (Minnesota, Michigan,
Wisconsin, New York, Connecticut, Massachussetts, Rhode Island, Delaware,
New hampshire, and Maine) in May 1972. This working paper describes the
field and laboratory methods which were used in lake, stream, and rnuni-
cipal sewage treatment plant sampling and analysis for these states.*
*Due to substantial changes in equipment, techniques, and analyses
performed in subsequent years of the Survey, this document should be
utilized only with data collected from the above ten states.
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PARTICIPATING LABORATORIES
Each of the participating laboratories, the Pacific Northwest
Environmental Research Laboratory-Corvallis (PNERL), the National
Environmental Research Center-Las Vegas (NERC-LV), and the Head-
quarters Staff, National Eutrophication Survey, Office of Research
and Development, Washington, D.C. (NES/HQS), and others have clearly
defined roles in the functional organization of the Survey. Table 1
lists the primary responsibilities of the participating agencies,
laboratories, and/or individuals.
SELECTION OF LAKES
Lakes and reservoirs which were included in the Survey in 1972 were
selected through discussions with state water pollution agency personnel
and EPA Regional Offices. The following selection criteria were used:
1. the lake was impacted by a municipal sewage treatment plant (MSTP)
effluent either by direct discharge to the lake or by discharge to
a tributary within approximately 25 miles of the lake;
2. was 100 surface acres or greater in size;
3. had a mean hydraulic residence time of no less than 30 days.
Specific selection criteria were waived for some lakes of particular
state interest.
Table 2 indicates the number of lakes selected in each state, the
number of associated stream sites and MSTP effluents sampled, and the
date stream sampling was initiated in each state. Stream sampling con-
tinued for 12 months following start-up. The Appendix lists, by state
and county, those lakes and reservoirs sampled in 1972.
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TABLE 1
NATIONAL EUTROPHICATION SURVEY RESPONSIBILITIES
FUNCTION PNERL NERC-LV NES/HQS OTHERS
I. Planning and Coordination X X X
II. Selection of Lakes
A. Preliminary x 1,2
B. Final X X X
III. Lake Sampling
A. Procedures X
B. Sample procurement X
C. Field analyses X
D. Preliminary lake evaluation X
E. Aircreft support X
F. Sample and data handling X
IV Tributary Sampling
A. Procedures X
B. Sample procurement X 1,3
C. Sample and data handling X
D. Stream flow data X 4
V. Sewage Treatment Plant Sampling
A Procedures X
B. Sample procurement X 5
C. Sample and data handling X
VI. Chemical Analyses
A. Lake samples X
B. Tributary samples X
C. Sewage treatment plant samples X
D. Quality control
1. Within lab X X
2 Interlab X
VII. Biological Analyses
A. Chlorophyll a X
B. Phytoplankton identification X 6
C. Algal Assay Procedure X
D. Pathogenic protozoa, bacteria X 7,8
VIII Land-Use Studies
A Watershed selection X
B. Imagery acquisition X
C. Imagery interpretation X
IX. Data Analyses and Report Preparation X X X 1,2*
1. State pollution control agency
2. EPA Regional Office
3. State National Guard Units
4. U.S Geological Survey
5. Municipal sewage treatment plant operatore
6. Dr. Charles Goldman, University of California at Davis, contractor
7. Dr Shih L. Chang, Water Supply Research Laboratory, Cincinnati, Ohio
8. Dr. Victor Cabelli, Northeast Water Supply Laboratory, Narragansett, Rhode Island
*Review and Coimnent
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TABLE 2
NUMBER OF LAKES AND START-UP DATES
OF STREAM SAMPLING IN NORTHEASTERN STATES
NUMBER OF MONTH AND YEAR
NUMBER OF NUMBER OF SAMPLED STREAM SAMPLING
STATE NES LAKES STREAM SITES WASTE EFFLUENTS INITIATED*
Vermont 7 52 23 July 1972
Connecticut 8 74 17 August 1972
Rhode Island 3 28 1 August 1972
New Hampshire 4 52 5 August 1972
Massachusetts 8 37 15 September 1972
Maine 9 59 5 September 1972
Wisconsin 46 170 16 September 1972
Minnesota 74 231 56 October 1972
Michigan 37 170 51 October 1972
New York 25 242 36 November 1972
*Lake sampling completed in 1972 by EPA, NERC-LV
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FIELD SAMPLING METHODS
Lakes
Lakes and sampling sites were located using U.S. Geological Survey (USGS)
7 1/2’ quadrangles whenever possible. When these were not available, 15’ or
1:250,000 series USGS maps were employed. In some instances bathymetric maps
were obtained through the assistance of state or regional agencies; these were
invaluable in selecting sampling sites. Unfortunately, many of the lakes
included in the Survey either had not been bathymetrically mapped or the
maps could not be obtained prior to sampling.
Sampling sites were selected based upon available information on lake
morphometry, potential major sources of nutrient input, and the on—site
judgment of the lininologist on the helicopter. Primary sampling sites were
chosen to reflect the deepest portion of each major basin in a test lake.
Where many basins were present, selection was guided by nutrient source
information on hand. The number of sampling sites for a test lake was
limited commensurate with the survey nature of the program. After se-
lection, site locations were marked and numbered on a quadrangle map.
From these, map coordinates were determined and entered on a site-description
form. Occasionally a sampling locat’ion was modified, deleted, or added
because of subsequent information received relevant to the basic site-
selection criteria.
Lake sampling was accomplished by two sampling teams, each consisting
of a limnologist, pilot, and sampling technician, operating from pontoon—
equipped Bell UH-1H helicopters. A mobile field laboratory provided
analytical support.
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The helicopters were equipped with electric winches and approximately
200 feet of hollow-core, multi-conductor cable attached to a submersible
pump and an Interocean Systems sensor capable of making in situ measurements
of conductivity, temperature, optical transmissivity, dissolved oxygen, pH,
and depth. Unfortunately, the pH and dissolved oxygen sensors were often
inoperative necessitating collection of physical water samples for these
parameters. An echo sounder, Secchi disc, sample containers and related
equipment items necessary for water sampling were also carried in each
helicopter.
After landing at the approximate site, the helicopter was water—
taxied in the area to locate the deepest nearby water. There a small
buoy was deployed to serve as a reference to the pilot for maintaining
the helicopter on station. Compass bearings were taken to prominent
landmarks from each sample site to permit return to the same location on
subsequent sampling rounds. Observations were recorded concerning general
lake appearance, phytoplankton bloom conditions, and shoreline development;
Secchi disc readings were made, and bucket—dipped surface water samples
were collected.
After the sensor—pump package was immersed, sensor outputs were checked
and the sensor was lowered slowly through the water column until it contacted
bottom. It was then raised to a point four feet off the bottom to avoid
pump damage from sediments entering the intake. The digital readout of each
sensor at that depth was recorded and the submersible pump was activated.
Water samples were collected after allowing sufficient time for the pump to
completely purge the hollow cable of water from the previous station. By
that time, depths had been selected for the collection of other water samples
that would best represent the water column. Upon completion of sampling near
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the bottom, the sensor was raised to the next level, digital values were
recorded, and water samples pumped. This process was repeated at each depth
selected for collection of water samples at a given site.
Integrated samples for algal identification or chlorophyll-a analysis
were collected by continuing to pump while raising or lowering the sensor
package. Water collection was timed to provide a uniform mixture of water
from the surface to 15 feet, or to a point just off the bottom within water
less than 15 feet deep.
At each sampling depth water samples were collected for nutrient, alka—
unity, pH, conductivity, and dissolved oxygen determinations. For nutrient
analysis two eight—ounce sample bottles were filled and the samples immedi-
ately preserved with mercuric chloride.
Samples for dissolved oxygen determinations were collected in 300 ml
BOD bottles, immediately fixed with Hach powder pillow reagents, and stored
out of direct sunlight. Samples for pH, conductivity, and chlorophyll—a
analyses were collected in polyethylene bottles and refrigerated in the dark
until completion of the day’s sampling operation. Algal identification
samples were preserved with acid Lugol’s solution aboard the helicopter.
Conductivity and pH electrode determinations were made as soon as
possible following their return to the field laboratory at the end of the
day’s sampling. A Beckman Electromate portable pH meter and combination
electrode were used to determine pH. Conductivity measurements were made
with a Beckman Model RB338 conductivity bridge. These were utilized
primarily as a check on the in situ sensors, but, on occasions, were the
primary data. Dissolved oxygen samples were titrated with phenylarsine
oxide in the mobile field laboratory within 16 hours after collection.
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Chlorophyll-a analyses were performed at the end of each day in the
trailer laboratory according to the fluorometric procedure described
by Yentsch and Menzel (1963).* One of each pair of nutrient salTtples
was filtered through a 0.45 micron HA Millipore filter into a clean
polyethylene bottle, recapped, and, along with its unfiltered counter-
part, forwarded to NERC-LV for analysis.
During the last sampling period, a five-gallon algal assay sample
was obtained by compositing water collected at each sampling level and
combining such samples from each site on a lake. If a lake had more
than four stations, groups of sites were combined into two or more
polyethylene cubitainers. The unpreserved algal assay samples were
forwarded to PNEPL for processing.
Municipal Sewage Treatment Plant
With the cooperation of state agencies, an attempt was made to
identify all municipal sewage treatment plants (MSTP) discharging
directly or indirectly into each lake. The operator at each MSTP was
requested to provide monthly effluent samples for a period of one year.
Each operator who agreed to cooperate was provided with a sampling kit
including instructions, sample containers, sample labels, mercuric
chloride preservative, shipping boxes, and pre-addressed, franked
shipping labels.
*Chlorophy].1_a analyses during 1972 were often delayed due to lack of
sufficient personnel. Subsequent studies suggest that short—term frozen
storage of filtered samples can give rise to chlorophyll—a losses in excess
of 20%: The data listings in STORET must be considered subject to a potential
error of this magnitude.
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He was asked to provide one of the following samples (listed in
order of descending preference)
1. a once-monthly 24-hour composite sample (proportional
composite if flows were metered or measured),
2. a once-monthly 8-, 10-, or 12-hour composite sample
(proportional if flows were metered or measured),
3. a once-monthly modified composite sample consisting
of about 500 ml collected at 11 a.m. and another
500 ml collected at 4 p.m. of the same day, or
4. a once-monthly single grab sample of about one liter
collected on a weekday between the hours of 8 n.M.
and 8 P.M.
Following collection, the plant operator preserved the sample by adding
to it the contents of a vial containing sufficient mercuric chloride to
achieve a concentration of 400 mg/l in the sample. The sample label was
completed by the sample collector and included data on sample type, date,
mean flow for the day of sampling, and mean daily flow for the month in
which the samples were collected. Samples were mailed to PNERL for
analysis.
Tributaries and Outlets
Sampling sites were selected on significant tributaries to each lake
near the point where the tributary discharged to the lake. Where municipal
waste discharges were located on tributaries, sampling sites were also
designated upstream from the point of effluent discharge. Sampling sites
for outlets of lakes or reservoirs were located at the nearest feasible
sampling point downstream from the water body being surveyed.
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Monthly samples at the designated stream sites were collected through
the volunteer efforts of the National Guard in each of the involved states.
When sampling was started in any of the states, a scientist from EPA or the
state agency accompanied each National Guard sampling team to each site during
the first sampling to train the team in proper techniques of sample collection,
preservation and handling. During the first sampling, the unique six—digit
station number was stenciled on the bridge or another permanent landmark at
the sampling site to insure positive identification of the site. Subsequent
monthly sampling for a period of one year, plus two additional samples during
high flow periods, was done exclusively by the National Guard sampling teams.
Stream samples were collected in clean, previously unused, wide-mouth,
one-liter polyvinyl chloride bottles. These were inserted in a sampler
consisting of a section of plastic pipe with a cross—bar bottle retainer at
one end and rubber tubing stretched across the other end to secure the bottle.
A rope was attached to the sampler to lower it from a bridge or stream bank to
the water surface. The water collected in the sample bottle at each site was
essentially a surface grab sample, although the sampling rig was lowered to
mid-depth in the stream before it was retrieved.
Following sample collection at each site, the Guard team completed a
label attached to each bottle recording the stream name, station number, date,
time, and signature of the individual responsible for collecting the sample.
The sample was preserved at the site with mercuric chloride. Following
inventory at the Guard base, samples were sent to PNERL for analysis.
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ANALYTICAL METHODS
Nutrient Analyses
The analytical methods utilized to process the samples at both
NERC-Corvallis and NERC-LV are presented in Table 3. All of the analyses
were performed utilizing adaptations of automated procedures described in
“Methods for Chemical Analysis of Water and Wastes” (EPA, 1971).
It should be noted that there were some differences in the analyses
performed at each laboratory. The lake water samples were analyzed at
NERC-LV for total phosphorus, total dissolved phosphorus, nitrite-nitrate-N,
ammonia-N, and total alkalinity. The stream and waste water effluent samples
were processed at NERC-Corvallis where total phosphorus, dissolved orthophos-
phorus, nitrite-N, nitrate-N, nitrite-nitrate-N, ammonia-N, and total
Kjeldahl nitrogen analyses were performed.
USGS ESTIMATES OF STREAM FLOWS
AND DRAINAGE AREAS
For each sampled stream, the various District Offices of the USGS
made estimates of the mean flow for the day of sampling, the flow for
each month of sampling, and the “normalized” mean flow for each month
(i.e., flows expected during a period of average precipitation and
hydrology). In addition, runoff estimates were made for the unsampled
portion of the total watershed of each lake and the area of the drainage
basin for each sampled tributary stream and for each lake or reservoir
was provided.
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TABLE 3
ANALYTICAL METHODS AND
PRECISION OF LABORATORY ANALYSES*
PARAMETER
Dissolved Single reagent methods involving +0.005 mg/i
Orthophosphate colorometric determination of or +5%
antimoriy-phosphomolybdate complex.
Total Dissolved Filtration and persulfate oxidation +0.005 mg/i
Phosphorus followed by the above method for or +5%
dissolved orthophosphate.
Total Phosphorus Persulfate oxidation followed by the ±0.005 mg/i
above method for dissolved orthophos- or +5%
phate.
Nitrite-N Diazotization of sulfanilamide by +0.001 mg/i
nitrite coupled with or ±2%
N-(l-naphthyl) -ethylene diainine.
Nitrite-Nitrate-N Cadmium reduction followed by the ±0.010 mg/i
above method for Nitrite-N. or
Nitrate-N Determined by difference between the ±0.010 mg/i
preceding two reactions. or
Ammonia-N Alkaline phenol hypochiorite reaction ±0.005 mg/i
producing indophenol blue. or
Kje ldah l-N Acid digestion followed by the above ±0.10 mg/i
procedure for ammonia nitrogen, or +5%
Total Alkalinity Methyl orange colorometric. ±0.5 or
*Although the % precision value does not change, wastewater analyses precision
values are an order of magnitude higher than those expressed (i.e. ±0.05 mg/i
vice +0.005 mg/i).
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In some instances, flow gages were present at sampling sites or
within a reasonable distance and were used to provide flow estimates.
In cases where sampled tributaries were ungaged, flow estimates were based
on runoff patterns at the nearest gaged strewn system. Where available, flow
information was also obtained from other sources, such as the Corps of
Engineers or power companies which maintain records of reservoir discharge.
The errors in drainage area measurements and flow estimates varied from
one area to another and were highly dependent on the availability of topo-
graphic maps of the appropriate scale, the number of gaged stream sites for
a given lake system, land relief, and other factors. In general, measurements
or estimates which were provided by USGS for the larger drainage areas
were the best, since these were subject to less severe fluctuations in stream
flow within a given period of time.
Table 4 summarizes the accuracy of flow estimates and drainage area
calculations by state as provided by the District Offices of the USGS.
ESTIMATES OF NUTRIENT LOADINGS
Tributaries and Outlets
Lake tributary and outlet nutrient loads included in each of the lake
reports were estimated for a “normalized” or average flow year rather than
for the year in which samples were collected. This approach was used be-
cause it was deemed more important to determine what sewage treatment plant
contributions or land-runoff contributions were under average conditions
rather than during any extreme hydrological conditions which may have oc-
curred during the year of sampling.
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TABLE 4
Connecticut
+1%
gaged +10%
ungaged +20%
gaged ±10%
ungaged +20%
Normalized
Mean
Monthly
Flow
gaged +10%
ungaged ±12% high flow
ungaged ±27% low flow
Mean
Annual
Flow
gaged 2
ungaged +30% (>20 mi
(<20 mi 2 )
gaged
ungaged ±20% (>20 mi 2 )
±50% (<20 mi 2 )
Maine ungaged accuracies are for worst low flow conditions and would be substantially better for much of the year.
gaged ±15%
ungaged ±20%
Estimates provided for
74% of the sites had
accuracy of ±25%.
Remainder of sites up
to ±40%.
gaged ±15%
ungaged ±20%
Slightly better accuracy
than daily estimates.
gaged ±15%
ungeged ±20%
Slightly better accuracy
than daily estimates.
Slightly better accuracy
than daily estimates.
Minnesota with
a few ±10%
gaged ±10%
ungaged ±25-50% with
greater error for
D.A <10 on 2
gaged
ungaged ±10-25% with
50% for D.A. <10 mi 2
gaged
ungaged - same as
mean monthly
gaged
ungaged - same as
mean monthly
New Hampshire
+1%
gaged ±15%
ungaged ±20%
gaged +15%
ungaged ±20%
gaged ±15%
ungaged ±20%
gaged ±15%
ungaged ±20%
± ‘ except for
small basins at
+10%
Estimates provided for
79% of the sites had
accuracy of ±5-25%. Re-
mainder of sites up to
+50%
A SUMMARY OF ACCURACY OF FLC*J ESTIMATES AND DRAINAGE AREA
ASUREMENTS PROVIDED BY U.S. GEOLOGICAL SURVEY
Mean
Mean
Drainage
Daily
Monthly
State Areas
Flow
Flow
Maine ±1%
Massachusetts ±1%
Michigan
gaged
ungaged ±200%
gaged
New York
a
Better than daily.
+ 15%
No value
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(TABLE 4 - Continued)
Normalized
Mean Mean Mean Mean
Drainage Daily Monthly Monthly Annual
State Areas Flow Flow Flow Flow
Rhode Island +1% gaged +15% gaged +15% gaged +15% gaged ±15%
ungaged +20% ungaged +20% ungaged +20% ungaged ±20%
Vermont +1% gaged ±15% gaged +15% gaged +15% gaged ±15%
ungaged ±20% ungaged ±20% ungaged ±20%
W i sconsin +0.5% +40% Somewhat better Average ±Th% No value
than daily flows
(7I
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Normally, 14 samples were collected from each stream site. Occasionally
the number of data points was less than 14 due to a sample or two not being
collected during winter ice conditions, sample loss, breakage, or laboratory
error. Although these are adequate data to provide a reasonable estimate of
the average concentration for a given stream for the sampled year, the data
from any one site are not adequate to satisfactorily estimate the relation-
ship between flow and concentration at that site. Variations in flow both
within and between years make it unsatisfactory to obtain a loading estimate
simply by multiplying the observed average concentration times the annual
normalized flow.
The procedure used was to estimate from combined data on a large number
of streams the extent of the relationship between concentration and flow for
each nutrient. The value so estimated represented the percent change in
concentration resulting from a given percent change in flow. This relation
does seam to be reasonably constant from stream to stream, although different
for the two major nutrients (a stronger relation for phosphorus than for
nitrogen). The appropriate statistical procedure for estimating this para-
meter is to compute the average slope from a large number of linear regressions,
for individual streams, of log concentration on log flow. This was carried
out using 250 sampling sites in northeastern and northcentral states. It
was found that, on the average, a 1% change in flow results in a —0.11%
change in phosphorus concentration and a -0.06% change in nitrogen concen-
tration.
The method of estimating loading was essentially to use these estimated
relationships to adjust the concentrations to what they would have been for
each month under normalized flow conditions, and then add up the estimated
loadings for the 12 months. The annual nutrient load, expressed as
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pounds/year, was thus calculated by:
12
Annual load = 164.502 C Y S E NP.
1 1
Where:
164.502 = factor including average number of days
per month and conversion of concentration
and flow to pounds per day,
c = mean nutrient concentration in the sampled stream,
NP. = normalized flow for th month,
b g NP - log tv}
Y=l0
b(log NP. — log NP) 12
s = { NP. ‘ 10 1 }/ NP.,
1 1 1
log NP = mean log normalized flow,
log 14F = mean log monthly flow for year sampled,
and b = -0.11 for phosphorus, -0.06 for nitrogen.
The “Y factor adjusts the data to account for the fact that the year
in which the samples were collected may have been extremely wet or dry
which would have had an influence on measured contributions. The US”
factor adjusts the data to account for seasonal flow variations.
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The net result of the regression analysis and the formula is an
annual loading value which is generally within a few percent of the
loading which would be estimated if it were assumed that nutrient con-
centrations did not vary with changes in stream flow.
In analyzing the data for a tributary having a point source upstream
from the sampling point, the total stream load was estimated first by
the method detailed above. If the point source was located reasonably
close to the sampling site, the total annual contribution to the stream
was subtracted from the total nutrient load at the sampling site, and the
difference was attributed to nonpoint-source input. If the point source
was located several miles upstream from the sampling point, the scientist
determining the nutrient loadings analyzed the total stream load (including
the point source), the magnitude of the point-source load, and the nonpoint-
source load of other stream systems in the area to determine what portion of
the nutrient load at the sampling site could logically be attributed to the
point source and subtracted from the total stream load. This procedure was
not standardized and was performed on an individual basis for each stream
system. However, the general rule was to assume that 100% of the point—source
•load eventually reached the lake or reservoir.
Sampled streams usually included most, but not all, of the lake watershed.
Unsampled streams, if any, and drainage from the lakeshore area also contributed
nutrients. The nutrient contribution of the unsainpled portion of the drainage
area was estimated by using the average nutrient export per unit area of
sampled stream drainage and multiplying that by the area of the unsaxnpled
portion.
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Some judgment factors were included in this estimate and how it was
made. If point sources strongly influenced one or more sampled streams in
a particular lake system, the scientist may have selected nutrient export
values from a single stream to estimate loadings from the unsampled portion
of the drainage area.
Variations from the above procedure, if any, are noted in the individual
lake reports.
Municipal Sewage Treatment Plants
If the operator of a MSTP impacting a surveyed lake submitted effluent
samples for analysis, the results were used to estimate nutrient discharge.
For these sampled plants, the nutrient loads per million gallons of effluent
were calculated for each day of sampling and averaged for the total sampling
period. Mean daily flows for each month of sampling were also averaged and
the total annual loads in lbs/year were estimated according to the following
equation:
Annual Load = (D) (F) (365)
where: D = Mean daily load in pounds per million gallons.
F = Mean daily flow in million gallons.
If a plant was not sampled, the nutrient loads were estimated on the
basis of sewered population or the 1970 census figures for the municipality
if no better sewered population estimate could be obtained. Flows were
estimated at 100 gallons/capita/day.
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For areas not under a phosphate detergent ban, the following per capita
estimates of total phosphorus and nitrogen contributions were useth
Total P Total N
( lbs/capita/yr) ( lbs/capita/yr )
Treated Waste 2.5 7.5
Raw Waste 3.5 9.4
The 3.5 lbs total P/capita/year for raw waste discharge was taken
from Bartsch (1972). For treated waste it was assumed that regardless of
treatment type, approximately 29% of the total phosphorus would be removed
leaving a contribution of 2.5 lbs/capita/year.
The nitrogen value of 7.5 lbs/capita/year was derived from the information
that nitrogen to phosphorus ratios in wastewater range from 3-6 (Bartsch, 1972)
and that, on the average, treatment removes only 20% of the total nitrogen.
Septic Tanks
Whenever data on the number of lakeshore septic tanks or septic tank
nutrient contributions were available, which was infrequently, they were
used. In the absence of any given data, the number of dwellings within
100 yards of the lake were counted on the most recent USGS quadrangle
map. It was assumed that on a year-long average, 2.5 people occupied each
dwelling. Where lakeshore resorts, parks, and/or campgrounds were known,
it was assumed that all were served by septic tanks and that each resort
was the equivalent of ten dwellings, that the population of each park was
25 persons per day for four months, and that the population of each camp
was 50 persons per day for four months.
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It was also assumed that after septic tank treatment and discharge to
the adsorption field that only 0.25 lbs P/capita/year reached the lake. For
nitrogen, which is less amenable to removal by treatment or by adsorption to
soil particles, it was assumed that 100% of the nitrogen or 9.4 lbs N/capital
year reached the lake from septic tank systems on the lakeshore.
Precipitation
A figure of 9.634 lbs of total nitrogen/acre lake surface/year was
used as an estimate of nitrogen in precipitation. The estimate was the
average result reported by Weible (1969) and Corey, et al. (1967) for
areas receiving approximately 30 inches of rainfall per year.
An estimate of 0.156 lbs total phosphorus/acre/year was used to
represent total phosphorus in precipitation. This estimate, which is
probably conservative, lies between the number reported by Corey, et al.
(1967) for soluble phosphorus and the lower end of the range reported by
Weible (1969) for the Cincinnati, Ohio area.
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ALGAL ASSAY
Upon arrival at the laboratory, the algal assay samples were frozen
until processing could begin. The procedures used in the algal assay test
were basically those outlined in the publication entitled Algal Assay
Procedure Bottle Test (EPA, 1971). Each sample was autoclaved at 121°C
and 15 psi for 10-30 minutes to kill indigenous organisms and soluhilize
nutrients bound by particulate matter and was then filtered. Chemical
analyses for nutrients and other constituents were performed before and
after autoclaving. *
Each lake water sample was treated witi’ several nutrient concentrations
in separate flasks. In addition, a lake water control with no nutrient sup-
plement was assayed. Nutrient spikes included 0.005 mg/i phosphorus, 0.02 mg/i
phosphorus, 0.05 mg/i phosphorus, 10.0 mg/l nitrogen, and a combination of
0.05 mg/l phosphorus plus 10.0 mg/i nitrogen.
After the various nutrient additions had been made to each set of lake
water samples, each flask was inoculated with 1,000 cells/ml of the test
alga, Selenastrum capricornutuni . Following inoculation the cultures were
incubated for 14 days at 24°C on gyrorotary shakers under 400 foot-candies of
continuous light. Algal growth was monitored throughout the incubation
*Results of nutrient analyses performed on unpreserved water samples
prior to autociaving often differed substantially from those of corresponding
mercuric chloride preserved water samples. Some of these discrepancies may be
attributed to the differences in sampling procedures for the two types of
samples. Most, however, were due to adsorption onto the container walls
during prolonged storage. In particular, significant losses of phosphorus and
inorganic nitrogen were often noted. Because of these losses, the algal assay
results are somewhat suspect but are believed to be usable if considered in
context with inorganic nitrogen: dissolved phosphorus ratios computed from
preserved water samples obtained on the date of algal assay sampling.
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23
period by cell counts and mean cell-volume measurements made with Coulter
electronic particle counters. The maximum growth attained was quantified
in terms of trig/i dry weight equivalents of the cell counts and mean cell
volumes.
ALGAL ENUMERATION AND IDENTIFICATION
Identification and differential counts of phytoplankton genera were
made with a microscope and counting chamber. The differential counts,
converted to organisms per ml, were entered into a WYLBUR computer file
to increase accessibility and facilitate use of the data in trophic
indices. The five most prevalent genera and total counts per ml were
tabulated for each lake sampled. Type slides and photomicrographs were
prepared to document specific and unique phytoplankton assemblages.
QUALITY CONTROL
PNERL
Quality control began with the receipt of the sample. After all
identifying information was logged, a laboratory number was assigned
identifying the sample and the analyses to be performed.
The data entered on laboratory request forms were teletyped to the
Oregon State University computer and.processed through the sample handling
and verification system (SHAVES) program (Krawczyk and Byrain, 1973).
At the request of the analyst, the SHAVES program produces a “run list”
for samples indicating, by laboratory number, the sequence in which the sample
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24
should be analyzed and also which samples should be replicated and/or spiked
with known quantities of the material being analyzed. The run list usually
specified a set of standards, 120 samples, and then another set of standards.
Every eighth sample was replicated, and every twentieth sample was spiked.
Analytical data readouts were entered into the computer which performed
a check on calculations and analytical accuracy and precision.
Blind samples (ten sub—samples identified as separate samples) were
sent through the system to check both the analysts and the equipment.
Scheduled replicate samples provided regular checks on analytical procedures.
NERC-Las Vegas Laboratory
In the Laboratory Operations Branch at NERC-Las Vegas every twentieth
sample was replicated and also spiked with a known amount of the constituent
being analyzed. An average of 15 blind samples per month were sent through
the laboratory as a check on analysts and instrumentation. Samples of known
of the analytical process.
Interlaboratory
Samples for interlaboratory comparison originated from several sources
including NES lake or stream samples, Methods Development and Quality
Assurance Research Laboratory, NERC—Cincinnati (MDQARL) reference samples
and unknown material furnished by International Field Year - Great Lakes
personnel. The results of the 1973 interlaboratory testing program for
various forms of nitrogen and phosphorus showed no significant differences
between laboratories, and compare very favorably with interlaboratory
comparisons for nutrients presented in Method Study 2 of the MDQARL.
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25
LITERATURE CITED
Bartsch, A.F. 1972. Pole of Phosphorus in Eutrophication. EPA Ecological
Research Series #EPA—R3—72—OOl.
Corey, R.B., A.D. Hasler, G.F. Lee, F.N. Schraufnagel, and T.L. Wirth. 1967.
Excessive Water Fertilization. Report to the Water Sub-Committee,
Natural Resources Committee of State Agencies.
Krawczyk, D.F., and K.V. Byram. 1973. Management System for an Analytical
Chemical Laboratory. xnerican Laboratory Vol. 5, pp. 55-64.
U.S. Environmental Protection Agency. 1971. Methods for Chemical Analysis
of Water and Wastes. Analytical Quality Control Laboratory, Cincinnati,
Ohio. 312 pages.
U.S. Environmental Protection Agency. 1971. Algal Assay Procedure Bottle
Test. National Eutrophication Research Program, Corvallis, Oregon.
82 pages.
Weibel, S.R. 1969. Urban Drainage as a Factor in Eutrophication. In: Eu-
trophication: Causes, Consequences, Correctives. National Academy of
Science, Washington, D.C. pp. 383-403.
Yentsch, C.S., and D.W. Menzel. 1963. A Method for the Determination of
Phytoplankton Chlorophyll and Phaeophytin by Flourescence. Deep Sea
Research. Vol. 10, pp. 221-231.
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26
APPENDIX
LAKE LISTS
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27
APPENDIX
CONNECT I CUT
STO ET # LAKE COUNTY
O9O1XX Aspinook Pond New London, Windhain
0902XX Bantam Lake Litchfield
0903XX Community Lake New Haven
0904XX Eagleville Lake Tolland
0905XX Hanover Pond New Haven
O91OXX Zoar Lake Fairfield, New Haven
O911XX Lillinoah Lake Litchfield, Fairfield,
New Haven
0912XX Shelton Lake Fairfield
MAINE
STOPET # LAKE COUNTY
2304XX Estes Lake York
2306XX Long Lake (Bridgeton) Cuntherland
2308XX Nattawamkeag Lake Aroostock
2309XX Moosehead Lake Piscataquis, Somerset
2310XX Rangeley Lake Franklin, Oxford
2311XX Sebago Lake Cuinberland
2312XX Sebasticook Lake Penobscot
2313XX Long Lake (St. Agatha) Aroostock
2314XX Bay of Naples Cuinberland
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28
MASSACHUSETTS
STORET # LAKE COUNTY
2502XX Hager Pond Middlesex
2503XX Harris Pond Worcester (Portion ilL
Providence Co., R.I.)
2504XX Maynard Impoundment Middlesex
2507XX Woods Pond Berkshire
2508XX Mattfield Impoundment Plymouth
2509xx Rochdale Pond Worcester
25l0xx Grist Millpond Middlesex
2511XX Billerica Impoundment Middlesex
25 12XX Northboro Impoundment Worcester
2513XX Hudson Impoundment Middlesex
NEW HAMPSHIRE
STOPET # LAKE COUNTY
3302XX Powder Mill Pond Hilisborough
3303XX Lake Winnipesaukee Carroll, Belknap
3305XX Kelly Falls Pond Hillsborough
3306XX Glenn Lake Hillsborough
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29
NEW YORK
STORET # LPJ(E COUNTY
3602XX Black Lake St. Lawrence
3603XX Canadarago Lake Otsego
3604xX Canandaigua Lake Ontario, Yates
3606XX Carry Falls Reservoir St. Lawrence
3607Xx Cassadaga Lake Chautauqua
3608XX Cayuga Lake Tompkins, Cayuga,
Seneca
3609XX Champlain Lake Essex, Clinton,
Washington
3610XX Chautauqua Lake Chautauqua
361 1xX Cross Lake Onondaga, Cayuga
3613XX Goodyear Lake Otsego
3615XX Huntington Lake Sullivan
3616XX Irondequoit Bay Monroe
3617XX Keuka Lake Steuben, Yates
3619XX Long Lake Hamilton
3622XX Oneida Lake Madison, Oneida,
Oswego, Onondaga
3623XX Onondaga Lake Onondaga
3625XX Otter Lake Cayuga
3627XX Owasco Lake Cayuga
3629XX Raquette Pond Franklin,
St. Lawrence
3630XX Round Lake Saratoga
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30
New York - Continued
STORET # LAKE COUNTY
3631XX Rondout Reservoir Sullivan, Ulster
3632XX Sacandaga Reservoir Fulton, Saratoga,
Haini iton
3633XX Saratoga Lake Saratoga
3634XX Schroon Lake Essex, Warren
3635XX Seneca Lake Schuyler, Ontario,
Seneca, Yates
3636XX Swan Lake Sullivan
3637XX Swinging Bridge Reservoir Sullivan
3639XX Conesus Livingston
3640XX Lower St. Regis Franklin
364 1XX Allegheny Cattaraugus
(Portion in Pa.)
RHODE ISLAND
STORET # LAKE COUNTY
4402XX Slatersville Reservoir Providence
4403XX Turner Reservoir Providence (Portion in
Bristol Co., Mass.)
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31
VERMONT
STORET 4t LAKE COUNTY
5001XX Champlain Lake Rutland, Addison,
Chittenden, Franklin,
Grand Isle (See New
York listings)
5002XX Clyde Pond Orleans
5005XX Harriman Reservoir Windham
5007XX Lainoille Lake Lainoille
5008XX Memphremagog Lake Orleans (Portion in
Canada)
5010XX Arrowhead Mountain Lake Chittenden, Franklin
5O11XX Waterbury Reservoir Washington, Lainoille
LiBRARY / EPA
Ndtlonal Environmental Research Ce t
200 S W :5th S’ eot
Corv Iis Oreq 97330
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32
MICHIGAN
STORET # LAKE COUNTY
2603XX Lake Allegan Allegan
2606XX Barton Lake Ka1a nazoo
2609XX Bellevil].e Lake Wayne
2610XX Betsie Lake Benzie
2613XX Brighton Lake Livingston
2617XX Lake Charlevoix Charlevoix
2618XX Lake Chemung Livingston
2621XX Lake Constantine St. Joseph
2624XX Deer Lake Marquette
2627XX Fallassburg Reservoir lonia
2629XX Ford Lake Washtenaw
2631XX Freiriont Lake Newaygo
2640XX Jordan Lake lonia, Barry
2643XX Kent Lake Oakland, Livingston
2648XX Lake Macatawa Ottawa
2649XX Manistee Lake Manistee
2659XX Muskegon Lake Muskegon
2665XX Pentwater Lake Oceana
2669XX Portage Lake Houghton
2671XX Randall Lake Branch
2672XX Rogers Pond Mecosta
2673XX Ross Lake Gladwin
2674XX Sanford Lake Midland
2679XX Sturgeon Lake Dickinson
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33
Michigan - Continued
STOPET # LAKE COUNTY
2683XX Thornapple Lake Barry
2685XX Union Lake Branch
2686XX Victoria Dam Ontonagon
2688XX White Lake Muskegon
2691XX Mona Lake Muskegon
2692XX Long Lake St. Joseph
2693XX St. Louis Reservoir Gratiot
2694XX Crystal Lake Montcalm
2695XX Higgins Lake Roscommon, Crawford
2696XX Houghton Lake Roscommon
2697XX Thompson Lake Livingston
2698XX Pere Marquette Lake Mason
2699XX Strawberry Lake Livingston
26AOXX Holloway Reservoir Lapeer, Genesse
26A1XX Caro Reservoir Tuscola
26A2XX Boardman Hydro Pond Grand Traverse
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34
MINNESOTA
STORET # LAKE COUNTY
2701XX Addie Lake McLeod
2702XX Albert Lea Lake Freeborn
2704XX Badger Lake Polk
2705XX Bartlett Lake Koochiching
2706xx Bear Lake Freeborn
2708XX Big Lake Stearns
2709XX Big Stone Lake Big Stone (Portion
in South Dakota)
271OXX Birch Lake Cass
2711XX Blackduck Lake Beltrami
2712XX Blackhoof Lake Crow Wing
2713XX Buffalo Lake Wright
2714XX Carrigan Lake Wright
27 15XX Cass Lake Beltraxni, Cass
2716XX Clearwater Lake Wright, Stearns
2717XX Clitherall Lake Otter Tail
27 19XX Cokato Lake Wright
2720XX Cranberry Lake Aitkin
2722XX Deer Lake Anoka
2725XX Elbow Lake St. Louis
2727XX Elk Lake Sherburne
2728XX Embarrass Lake St. Louis
2730XX Fall Lake St. Louis
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35
Minnesota - Continued
STOPET # LAKE COUNTY
2731XX Fanny Lake Douglas
2737XX Gull Lake Cass
2739XX Heron Lake Jackson
2745XX Lake of the Woods Roseau, Lake of the
Woods (Portion in
Canada)
2746XX Leech Lake Cass
2747Xx Lily Lake Blue Earth
2748XX Little Lake Grant
2749XX Whitewater Lake St. Louis
2750XX Madison Lake Blue Earth
275lXx Menomin (Mahnomen) Crow Wing
2752XX Malinedal Lake Pope
2753XX Maple Lake Douglas
2756XX Mashkenode Lake St. Louis
2757XX McQuade Lake St. Louis
2758XX Meuwissen Lake Carver
2760XX Minnetonka Lake Hennepin, Carver
2761XX Minnewaska Lake Pope
2765XX Pelican Lake St. Louis
2769XX Portage Lake Otter Tail
2770XX Pullman Lake Grant
2771XX Rabbit Lake Crow Wing
2776XX St Louis Bay St. Louis
2777XX Sakatah Lake Le Sueur, Rice
2780XX Shagawa Lake St. Louis
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36
Minnesota - Continued
STORET # LAKE COUNTY
2782XX Silver Lake McLeod
2783XX Six Mile Lake St. Louis
2784XX South Lake McLeod
2785XX St. Clair Lake Becker
2786XX Superior Bay St. Louis
2788XX Swan Lake Itasca
2792XX Trace Lake Todd
2793XX Trout Lake Itasca
2796XX Tuttle Lake Martin
2799XX Willow Lake Redwood
27A1XX Winona Lake Douglas
27A2XX Wolf Lake Beltrairti, HuJbard
27A3XX Woodcock Lake Kandiyohi
27A4XX Lake Pepin Coodhue, Wabasha
(See Wisconsin listing)
27A5XX Zuznbro Lake Olmsted, Wabasha
27A6XX Spring Lake Washington, Dakota
27A7XX St. Croix Washington (See
Wisconsin listing)
27A8XX Budd Lake Martin
27A9XX Forest Lake Washington
27BOXX White Bear Lake Ramsey, Washington
27B1XX Wagongo Lake Kandiyohi
27B2XX Green Lake Kandiyohi
27B3XX Nest Lake Kandlyohi
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37
Minnesota - Continued
STOPET # ____ COUNTY
27B4XX Darling Douglas
27B5XX Lake Le Homine Dieu Douglas
27B6XX Calhoun Hennepin
27B7XX Walimark (Mud) Lake Chisago
27B8XX Lost Lake St. Louis
27B9XX Lake Carlos Douglas
27COXX Aridrusia Lake Beltranii
27C1XX Lake Bemidji Beltrami
27C2XX Mud Lake (Hasca City) Itasca
27C3XX Cottonwood Lake Lyon
27C4XX Mud Lake (Wright City) Wright
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38
WISCONSIN
STOPET # LAKE COUNTY
5502XX A].toona Lake Eau Claire
5503XX Beaver Darn Lake Dodge
5508XX Butte Des Morts Lake Winnebago
5509XX Butternut Lake Ashland, Price
5510XX Castle Rock Flowage Juneau, Adams
5513XX Delavan Lake Walworth
5515XX Eau Claire Lake Eau Claire
5519XX Green Lake Green Lake
5520XX Kegonsa Lake Dane
5522XX Koshkonong Lake Dane, Jefferson, Rock
5531XX Nagawicka Lake Waukesha
5532XX Oconomowoc Lake Waukesha
5534XX Petenwell Flowage Wood, Adams, Juneau
5535XX Pigeon Lake Waupaca
5536XX Pine Lake Waukesha
5538XX Poygan Lake Waushara, Winnebago
5539XX Shawano Lake Shawano
5541XX Sinissippi Lake Dodge
5545XX Swan Lake Columbia
5546XX Tainter Lake Dunn
5548XX Town Line Lake Oneida
5550XX Wapogasset Lake Polk
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39
Wisconsin - Continued
STORET # LAKE COtJN’TY
5551XX Wausaw Lake Marathon
5554XX Winnebago Lake Fond Du Lac, Caluinet,
Winnebago
5555XX Wisconsin Lake Col umbia
5556XX Wissota Lake Chippewa
5557XX Pewaukee Lake Waukesha
5558XX Okauchee Lake Waukesha
5559XX Tichigan Lake Racine
5560xX Browns Lake Racine
556 1XX Lake Geneva Walworth
5562XX Como Lake Walworth
5563XX Lac La Belle Waukesha
5564XX Rock Lake Jefferson
5565XX Big Eau Pleine Reservoir Marathon, Portage
5566XX Round Lake Waupaca
5568XX Rome Pond Jefferson
5569XX Middle Lake Walworth
5570XX Grand Lake Green Lake
5571XX Crystal Lake Vilas
557 2XX Trout Lake Vilas
5573XX Long Lake Price
5574XX Willow Reservoir Oneida
5575XX Elk Lake Price
5576XX Yellow Lake Burnett
5577XX Beaver Dam Lake Barron
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40
Wisconsin - Continued
STORET # LAKE COUNTY
5578XX St. Croix Lake St. Croix, Pierce
(See Minnesota
listing)
5580XX St. Louis Bay Douglas (See
Minnesota listing)
5581XX Superior Bay Douglas (See
Minnesota listing)
5582XX Pepin Lake Pierce, Pepin,
Buffalo (See
Minnesota listing)
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