-------
SILVER LAKE
STORE! NO. 1008
I. CONCLUSIONS
A. Trophic Condition:
Silver Lake is classified as eutrophic based upon
Survey data. Heavy growths of aquatic weeds (spatter-
dock and smartweed) clog the upper reaches of the lake.
Potential for primary productivity as measured by algal
assay control yield, chlorophyll a^ levels, and nutrient
concentrations was high. Dissolved oxygen concentrations
were depressed during summer sampling, and water clarity
was generally low. Phytoplankton genera identified were
generally pollution-tolerant forms.
B. Rate-Limiting Nutrient:
Algal assay results indicate that at the time of
sampling, phosphorus and nitrogen were present in
sufficient concentrations that some unidentified nutrient
limited growth of the assay alga before either of the
major nutrients was exhausted. Lake data concerning the
ratios of inorganic nitrogen to orthophosphorus (greater
than 46:1 on all three sampling rounds) suggest that
phosphorus would become limiting well before available
nitrogen was depleted.
-------
C. Nutrient Controllability:
1. Point Sources - The mean annual phosphorus load
from point sources was estimated to be 44.3% of
the total load reaching Silver Lake. The Middletown
wastewater treatment plant contributed 44.2% of the
total load.
2. Nonpoint Sources - The mean annual phosphorus load
from nonpoint sources was 55.7% of the total load
reaching Silver Lake. Measured tributaries accounted
for 53.1% of the total phosphorus load, and the
remaining drainage areas were estimated to have
contributed 2.5%.
The present loading rate of 52.47 g P/m2/yr is
approximately six times the "dangerous" (eutrophic)
rate proposed by Vollenweider (in press) for a lake
of such volume and detention time. However,
Vollenweider's model probably does not apply to water
bodies with short hydraulic retention times, and the
hydraulic retention time of Silver Lake is only 8 days.
Further analysis of surrounding land uses and unknown
nutrient sources is needed before recommendations for
the improvement of water quality in Silver Lake can
be made.
-------
II. LAKE AND DRAINAGE BASIN CHARACTERISTICS
Lake and drainage basin characteristics are itemized
below. Lake surface area was provided by the State of
Delaware; mean depth was estimated based on survey data;
tributary flow data were provided by the Delaware District Office
of the U.S. Geological Survey (USGS) (outlet drainage area
includes the lake surface area). Mean hydraulic retention
time was obtained by dividing the lake volume by mean flow
of the outlet.
Precipitation values are estimated by methods as
outlined in National Eutrophication Survey (NES) Working
Paper No. 175. A table of metric/English conversions is
included as Appendix A.
A. Lake Morphometry:
2
1. Surface area: 0.15 km .
2. Mean depth: 1.5 meters.
3. Maximum depth: ? meters.
4. Volume: 0.225 x 106 m3.
5. Mean hydraulic retention time: 8 days.
-------
B. Tributary and Outlet (see Appendix C for flow data):
1. Tributaries -
Drainage Mean flow
Name • area(km2) (m3/sec)
A(2) Deep Creek 9.5 0.16
B(l) Unnamed Stream 5.4 0.09
Minor tributaries &
immediate drainage - 4.4 0.08
Totals 19.3 0.33
2. Outlet - A(l) Deep Creek 19.5 0.33
C. Precipitation:
1. Year of sampling: 132.5 centimeters.
2. Mean annual: 104.5 centimeters.
-------
III. LAKE WATER QUALITY SUMMARY
Silver Lake was sampled three times during the open-
water season of 1973 by means of a pontoon-equipped Huey
helicopter. Each time, samples for physical and chemical
parameters were collected from one station on the lake
and from a number of depths at that station (see map,
page v). During each visit, depth-integrated samples were
collected from the station for chlorophyll a_ analysis and
phytoplankton identification and enumeration. During the
first visit, an 18.9-liter depth-integrated sample was
composited for algal assays. The maximum depth sampled
was 2.4 meters. For a more detailed explanation of NES
methods, see NES Working Paper No. 175.
The results obtained are presented in full in
Appendix D and are summarized in III A for waters at
the surface and at the maximum depth for the sampling
site. Results of the phytoplankton counts and chlorophyll
a_ determinations are included in III B. Results of the
limiting nutrient study are presented in III C.
-------
A. PHYSICAL AND CHEMICAL CHARACTERISTICS
( 4/10/73 ) ( 7/20/73 ) ( 9/29/73 )
MAX MAX MAX
S*»» = 1 DEPTH S**» = 1 DEPTH S»»« = 1 DEPTH
RANGE RANGE RANGE
PARAMETER N* RANGE MEDIAN (METERS) N* RANGE MEDIAN (METERS) N* RANGE MEDIAN (METERS)
TEMPERATURE (DEG CENT)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN
0.-1.5 M DEPTH
2
1
(MG/L)
1
MAX DEPTH** i
CONDUCTIVITY (UMHOS)
0.-1.5 M DEPTH
MAX DEPTH**
2
1
12.1- 12.1
12.1- 12.1
9.2- 9.2
9.2- 9.2
200.- 200.
195.- 195.
12.1
12.1
9.2
9.2
200.
195.
0.0-
2.4-
1.2-
2.4-
0.0-
2.4-
1.2
2.4
1.2
2.4
1.2
2.4
2
1
2
1
2
1
21.2- 26.2
21.2- 21.2
2.0- 17.8
2.0- 2.0
217.- 224.
217.- 217.
23.7
21.2
9.9
2.0
221.
217.
0.0-
1.5-
0.0-
1 .5-
0.0-
1.5-
1.5
1.5
1.5
1.5
1.5
1.5
2
1
1
0
2
1
18.6- 20.2
18.6- 18.6
6.5- 6.5
222.- 224.
222.- 222.
19.4
18.6
6.5
223.
222.
0.0- 1.5
1.5- 1.5
0.0- 0.0
0.0- 1.5
1.5- 1.5
PH (STANDARD UNITS)
0.-1.5 M DEPTH
MAX DEPTH**
TOTAL ALKALINITY
0.-1.5 M DEPTH
MAX DEPTH**
TOTAL P (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED ORTHO P
0.-1.5 M DEPTH
N02*N03 (MG/L)
0.-1.5 M DEPTH
AMMONIA (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
KJELDAHL N (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
2
1
(MG/L)
2
1
2
1
(MG/L)
2
2
2
1
2
1
7.1- 7.1
7| -y |
• 1 7.1
21.- 22.
24.- 24.
0.244-0.245
0.247-0.247
0.097-0.099
0 . 096—0 .096
2.900-5.200
0.370-0.370
0 . 380— 0 .380
1.000-1.000
0.900-0.900
7.1
7. 1
22.
24.
0.244
0.247
0.098
0.096
4.050
0.370
0.380
1.000
0.900
0.0-
2.4-
0.0-
2.4-
0.0-
2.4-
0.0-
2/> —
.4-
0.0-
2A —
• **—
0.0-
2 A
.4-
0.0-
2.4-
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2.4
1.2
2 A
• **
1.2
2.4
1.2
2
1
2
1
2
1
2
2
2
1
2
1
6.6- 9.7
6.6— 6.6
27.- 31.
31.- 31.
0.102-0.120
0. 120—0. 120
0.015-0.049
0 .049—0.049
4.100-4.500
4.500—4.500
0.090-0.310
0.310-0.310
0.800-1.100
O.flOO-O.ROO
8.1
6.6
29.
31.
0.111
0.120
0.032
0.049
4.300
0.200
0.310
0.950
O.ROO
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1C*
*t>
0.0-
1.5-
0.0-
1 - 5—
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1C
• D
1.5
1.5
1.5
!.•;
1
0
1
0
1
0
1
0
1
0
1
0
1
n
7.7- 7.7
38.- 38.
0.211-0.211
0.101-0.101
4.470-4.470
0.220-0.220
1.700-1.700
7.7
38.
0.211
0.101
4.470
0.220
1.700
0.0- 0.0
0.0- 0.0
0.0- 0.0
0.0- 0.0
0.0- 0.0
0.0- 0.0
0.0- 0.0
SECCHI DISC (METERS)
1 0.5- 0.5 0.5 1 0.9- 0.9 0.9 1 1.3- 1.3 1.3
> N - NO. OF SAMPLES
*» MAXIMUM DEPTH SAMPLED AT EACH SITE
•*« S = NO. OF SITES SAMPLED ON THIS DATE
-------
B. Biological Characteristics:
1. Phytoplankton -
2.
Sampling
Data
07/20/73
09/29/73
Chlorophyll
Sampl i ng
Date
04/10/73
07/20/73
09/29/73
Dominant
Genera
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
a_ -
Station
Number
1
1
1
Flagellates
Micractinium
Schroederia
Nitzschia
Green cells
Other genera
Total
Scenedesmus
Flagellates
Coelastrum
Cosmerium
Staurastrum
Other genera
Total
Algal
Units
per ml
11,031
2,464
1,702
1,408
821
4,168
21,594
1,698
609
279
101
101
227
3,015
Chlorophyll a
(mi crograms/Ti ter )
8.6
52.8
18.7
-------
Ortho P
Conc.(mg/l)
0.128
0.178
0.178
0.128
Inorganic N
Conc.(mg/l)
4.664
4.664
5.664
5.664
Maximum yield
(mg/l-dry wt.)
30.2
31.1
29.9
25.6
8
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked -
Spike(mg/l)
Control
0.05 P
0.05 P + 1.0 N
1.00 N
2. Discussion -
The control yield of the assay alga, Selenastrum
capricornutum, indicates that the potential for primary
production in Silver Lake was high at the time of
sampling. Spikes with phosphorus and nitrogen alone,
or simultaneous addition of these two nutrients failed
to enhance the control yield. It appears that those
major nutrients are present in sufficient concentrations
to allow reduction of some undetermined nutritional
element to levels which are limiting to lake productivity.
The ratios of the mean inorganic nitrogen to ortho-
phosphorus for all three sampling dates were greater than
46:1, suggesting that phosphorus could become limiting
while nitrogen still remained at high levels.
-------
IV. NUTRIENT LOADINGS
(See Appendix E for data)
For the determination of nutrient loadings, the Delaware
National Guard collected monthly near-surface grab samples
from each of the tributary sites indicated on the map (page v),
except for the high runoff month of March when two samples
were collected. Sampling was begun in April 1973 and was
completed in March 1974.
Through an interagency agreement, stream flow estimates
for the year of sampling and a "normalized" or average year
were provided by the Delaware District Office of the USGS
for the tributary sites nearest the lake.
In this report, nutrient loads for sampled tributaries
were determined by using a modification of the USGS computer
program for calculating stream loadings. Nutrient loads
indicated for tributaries are those measured minus known point
source loads, if any.
Nutrient loadings for unsampled "minor tributaries and
immediate drainage" ("ZZ" of USGS) were estimated by using
the mean annual concentrations in Unnamed Stream at
Station B(l) and mean annual ZZ flow.
The operator of the Middletown wastewater treatment
plant provided monthly effluent samples and corresponding
flow data.
-------
10
A. Waste Sources:
1. Known municipal -
Name
Middletown
Population
Served
2,644
Treatment
Trickling
Filter
Mean Flow
(m3/d x 103)
0.852
Receiving
Water
Appoquinimink
River
2. Known industrial - None
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs -
% of
Source kg P/yr total
a. Tributaries (nonpoint load) -
A(2) Deep Creek 2,440 50.1
B(l) Unnamed Stream 145 3.0
b. Minor tributaries & immediate
drainage (nonpoint load) - 120 2.5
c. Known municipal STP's -
Middletown 2,155 44.2
d. • Septic tanks* - 5 0.1
e. Known industrial - None
f. Direct precipitation** - 5 0.1
Totals 4,870 100.0
2. Outputs - Deep Creek 2,520
3. Net annual P accumulation - 2,350
*Estimate based on 15 lakeshore residences.
**Estimated (see NES Working Paper No. 175).
-------
11
C. Annual Total Nitrogen Loading - Average Year:
1. Inputs -
% of
Source kg N/yr total
a. Tributaries (nonpoint load) -
A(2) Deep Creek 31,110 41.0
B(l) Unnamed Stream 20,375 26.9
b. Minor tributaries & immediate
drainage (nonpoint load) - 19,160 25.3
c. Known municipal STP's -
Middletown 4,845 6.4
d. Septic tanks* - 160 0.2
e. Known industrial - None
f. Direct precipitation** - 165 0.2
Totals 75,815 100.0
2. Outputs - Deep Creek 58,835
3. Net annual N accumulation - 16,980
D. Mean Annual Nonpoint Nutrient Export by Subdrainage Area:
Tributary kg P/km^/yr . kg N/km^/yr
A(2) Deep Creek 257 3,275
B(l) Unnamed Stream 27 3,773
*Estimate based on 15 lakeshore residences.
**Estimated (see NES Working Paper No. 175).
-------
E. Yearly Loading Rates:
In the following table, the existing phosphorus
loading rates are compared to those proposed by
Vollenweider (in press). Essentially, his "dangerous"
rate is the rate at which the receiving waters would
become eutrophic or remain eutrophic; his "permissible"
rate is that which would result in the receiving water
remaining oligotrophic or becoming oligotrophic if
morphometry permitted. A mesotrophic rate would be
considered one between "dangerous" and "permissible."
Total Yearly
Phosphorus Loading Rate
(grams/m^/year)
Estimated loading rate for Silver Lake 32.47
Vollenweider's "dangerous" or eutrophic rate 4.88
Vollenweider's "permissible" or oligotrophic rate 2.44
-------
13
V. LITERATURE REVIEWED
Ketelle, Martha J. and Paul D. Uttormark. 1971. "Problem
Lakes in the United States." U.S. Environmental
Protection Agency Project #16010 EHR. Univeristy of
Wisconsin, Madison, Wisconsin.
Lesser, Charles A. 1966. "Aquatic Vegetation Survey;
Federal Aid in Fish Restoration." Project #F-21-R.
Delaware Fish and Game Commission, Dover, Delaware.
U.S. Environmental Protection Agency. 1975. "National
Eutrophication Survey Methods 1973-1976." Working
Paper No. 175. NERC, Las Vegas, Nevada, and PNERL,
Corvallis, Oregon.
Vollenweider, Richard A. (in press). "Input-Output
Models." Schweiz. Z. Hydro!.
-------
VI. APPENDICES
APPENDIX A
CONVERSION FACTORS
-------
CONVERSION FACTORS
Hectares x 2.471 = acres
Meters x 3.281 = feet
Cubic meters x 8.107 x 10-4 = acre feet
Square kilometers x 0.3861 = square miles
Cubic meters/sec x 35.315 = cubic feet/sec
Centimeters x 0.3937 = inches
Kilograms x 2.205 = pounds
Kilograms/square kilometer x 5.711 = Ibs/square mile
-------
APPENDIX B
PARAMETRIC RANKINGS OF LAKES
SAMPLED BY NES IN 1973
STATE OF DELAWARE
-------
LAKE DATA TO BE USED IN RANKINGS
LAKE
CODE LAKE NAME
1002 KILLEN POND
1005 KOORES LAKE
1007 NOXONTOWN POND
1008 SILVER LAKE
1009 WILLIAMS POND
1030 TRUSSUM POND
MEDIAN
TOTAL P
0.170
0.245
0.160
0.227
0.042
0.038
MEDIAN
INORG N
1.610
2.400
0.530
4.750
2.010
1.280
500-
MEAN SEC
479.333
472.667
478.833
465.667
449.333
464.000
MEAN
CHLORA
116.200
81.267
37.600
26.700
30.100
5.100
15-
MIN DO
12.000
4.700
10.400
13.000
8.800
5.800
MEDI,
OISS ORTI
0.042
0.071
0.016
0.096
0.010
0.011
-------
PERCENT .OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES)
LAKE
CODE LAKE NAME
1002 KILLEN POND
1005 MOORES LAKE
1007 NQXONTOWN POND
1008 SILVER LAKE
1009 WILLIAMS POND
1010 TRUSSUM POND
MEDIAN
TOTAL P
40 (
0 (
60 (
20 (
80 (
100 (
2)
0)
3)
1)
4)
5)
MEDIAN
INORG N
60 (
20 (
100 (
0 (
40 (
80 (
3)
1)
5)
0)
2)
4)
500-
MEAN SEC
0 (
40 (
20 (
60 (
100 (
80 (
0)
2)
1)
3)
5)
4)
MEAN
CHLORA
0 <
20 (
40 (
80 (
60 (
100 (
0)
1)
2)
4)
3)
5)
15-
MIN
20 (
100 (
40 (
0 (
60 (
80 (
DO
1)
5)
2)
0)
3)
4)
MEDIAN
DISS ORTHO
40 (
20 (
60 (
0 (
100 (
80 (
2)
1)
3)
0)
5)
4)
-------
APPENDIX C
TRIBUTARY FLOW DATA
-------
TRIBUTARY FLOW INFORMATION FOR DELAWARE
10/20/75
LAKE CODE 1008
SILVER LAKE
7.51
MAR
TOTAL DRAINAGE AREA OF LAKE(SO MI)
SUB-DRAINAGE
TRIBUTARY AREA(SO MI) JAN FEB
1008A1
1008A2
1Q08B1
1008ZZ
TOTAL DRAINAGE AREA OF LAKE
SUM OF SUB-DRAINAGE AREAS
MEAN MONTHLY FLOWS AND DAILY FLOWS(CFS)
NORMALIZED FLOWS(CFS)
APR MAY JUN JUL AUG SEP
OCT
NOV
DEC
MEAN
7.51
3.68
2.08
1.75
14.50
7.00
3.90
3.60
15.50
7.50
4.20
3.80
17.20
8.30
4.70
4.20
12.90
6.20
3.50
3.20
10.00
4.70
2.70
2.60
10.20
4.90
2.80
2.50
8.80
4.30
2.40
2.10
11.60
5.60
3.10
2.90
9.60
4.60
2.60
2.40
7.60
3.60
2.00
2.00
10.30
5.00
2.80
2.50
12.00
5.80
3.20
3.00
11.66
5.61
3.15
2.90
TRIBUTARY MONTH YEAR
1008A1
1008A2
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
73
73
73
73
73
73
73
73
73
74
74
74
73
73
73
73
73
73
73
73
73
74
74
74
MEAN FLOW DAY
30.00
18.50
48.00
22.00
22.00
9.60
17.00
10.00
30.00
18.00
12.00
20.00
14.00
9.00
22.80
10.50
10.80
4.60
B.OO
4.90
14.00
8.80
5.90
9.90
28
20
25
23
20
16
28
16
4
8
5
11
28
20
25
23
20
16
28
16
4
8
5
11
SUMMARY
7.51
7.51
TOTAL FLOW IN » 140.20
TOTAL FLOW OUT * 140.20
FLOW DAY
FLOW DAY
FLOW
29.00
18.00
13.00
12.00
9.50
10.00
8.00
9.60
9.60
12.00
8.80
10.00
14.00
8.70
6.20
5.80
4.60
4.90
3.90
4.60
4.60
6.00
4.30
4.80
22
22
22
22
12.00
46.00
5.90
23.00
-------
TRIBUTARY FLOw INFORMATION FOR DELAWARE.
10/20/75
LAKE CODE 1008
SILVER LAKE
MEAN MONTHLY FLOWS AND DAILY FLOWS(CFS)
TRIBUTARY
1008B1
1008ZZ
MONTH
YEAR
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
73
73
73
73
73
73
73
73
73
74
74
74
73
73
73
73
73
73
73
73
73
74
7<+
74
MEAN FLOW DAY
8.20
5.00
13.90
4.90
6.00
2.60
4.60
2.80
8.20
5.00
3.20
5.60
6.70
4.30
10.90
5.00
5.20
2.20
3. 80
2.40
6.70
4.20
2.80
4.80
28
20
25
23
20
16
28
16
4
8
5
11
28
20
25
23
20
16
28
16
4
8
5
11
FLO* DAY
FLO* OAY
FLOW
8.20
4.90
3.50
3.20
2.60
2.80
2.20
2.60
2.60
3.40
2.40
2.70
6.70
4.20
3.00
2.80
2.20
2.40
1.90
2.20
2.20
2.90
2.10
2.30
22
22
22
22
3.20
13.00
2.80
11.00
-------
APPENDIX D
PHYSICAL AND CHEMICAL DATA
-------
STORET RETRIEVAL DATE 75/10/16
100801
39 26 15.0 075 41 40.0
SILVER LAKE
10 DELAWARE
DATE
FROM
TO
73/04/10
73/07/20
73/09/29
DATE
FROM
TO
73/04/10
73/07/20
73/09/29
TIME DEPTH
OF
DAY FEET
10 15 0000
10 15 0004
10 15 0008
12 10 0000
12 10 0005
10 10 0000
10 10 0005
TIME DEPTH
OF
DAY FEET
10 15 0000
10 15 0004
10 15 0008
12 10 0000
12 10 0005
10 10 0000
00010
MATER
TEMP
CENT
12.1
12.1
12.1
26.2
21.2
20.2
18.6
00665
PHOS-TOT
MG/L P
0.245
0.244
0.247
0.102
0.120
0.211
00300
DO
MG/L
9.2
9.2
17.8
2.0
6.5
32217
CHLRPHYL
A
UG/L
8.6
52.8
18.7
00077 00094
TRANSP CNOUCTVY
SECCH1 FIELD
INCHES MICROMHO
18
35
50
200
200
195
224
217
224
222
11EPALES
3
00400
PH
SU
7.10
7.10
7.10
9.70
6.60
7.70
00410
T ALK
CAC03
MG/L
22
21
24
27
31
38
2111202
0010
00610
NH3-N
TOTAL
MG/L
0.370
0.370
0.380
0.090
0.310
0.220
FEET DEPTH
00625
TOT KJEL
N
MG/L
1.000
1.000
0.900
1.100
0.800
1.700
00630
N028.N03
N-TOTAL
MG/L
2.900
5.200
4.500
4.100
4.500
4.470
00671
PHOS-DIS
ORTHO
MG/L P
0.097
0.099
0.096
0.015
0.049
0.101
-------
APPENDIX E
TRIBUTARY AND WASTEWATER
TREATMENT PLANT DATA
-------
STORET RETRIEVAL DATE 75/10/16
1008A1
39 26 30.0 075 41 30.0
DEEP CREEK
10 7.5 MIDDLETOWN
0/SILVER LAKE
BRDG 2 MI SE OF MIDDLETOWN
11EPALES 2111204
4 0000 FEET
DEPTH
DATE
FROM
TO
73/04/28
73/05/20
73/06/25
73/07/23
73/08/20
73/09/16
73/10/28
73/11/16
73/12/04
74/01/08
74/02/05
74/03/11
74/03/22
TIME DEPTH
OF
DAY FEET
09 40
13 35
13 30
09 25
10 45
16 45
14 00
14 00
09 40
14 05
15 00
10 00
10 30
00630
N02&N03
N-TOTAL
MG/L
4.800
4.850
3.600
4.500
3.300
4.600
5.000
4.620
5.000
6.000
5.200
4.800
00625
TOT KJEL
N
MG/L
1.150
0.600
2.300
1.260
2.200
1.760
1.650
1.050
1.000
1.100
0.900
1.300
1.200
00610
NH3-N
TOTAL
MG/L
0.260
0.198
0.067
0.080
0.220
0.510
0.046
0.210
0.480
0.528
0.250
0.185
0.180
00671
PHOS-DIS
ORTHO
MG/L P
0.105
0.115
0.058
0.048
0.034
0.063
0.066
0.115
0.076
0.120
0.100
0.045
0.055
00665
PHOS-TOT
MG/L P
0.200
0.200
0.230
0.150
0.180
0.180
0.230
0.315
0.230
0.290
0.260
0.230
0.185
-------
STORE! RETRIEVAL DATE 75/10/16
1008A2
39 26 00.0 075 43 00.0
DEEP CREEK
10 7.5 MIDDLETOWN
I/SILVER LAKE
ST HWY 71 8RDG S EDGE OF MIDDLETON
11EPALES 2111204
4 0000 FEET DEPTH
DATE
FROM
TO
73/04/28
73/05/20
73/06/25
73/07/23
73/08/20
73/09/16
73/10/28
73/11/16
73/12/04
74/01/08
74/02/05
74/03/11
74/03/22
00630 00625
TIME DEPTH N02&.N03 TOT KJEL
OF N-TOTAL N
DAY FEET
08
12
12
09
09
15
13
14
09
13
14
09
09
30
40
30
05
55
30
30
10
15
30
15
10
50
MG/L
4.900
6.050
6.200
6.300
4.900
6.400
5.700
5.600
6.400
6.300
6.100
5.200
MG/L
1.
1.
1,
0.
0,
2,
2,
1,
1.
1.
2.
1,
,760
,540
,320
,380
,360
,100
,700
,050
,600
,900
,100
,700
2.600
00610 00671 00665
NH3-N PHOS-DIS PHOS-TOT
TOTAL ORTHO
MG/L
0
0
0
0
0
1
2
0
0
1
1
0
0
.430
.730
.590
.189
.350
.080
.100
.580
.990
.300
.100
.560
.315
MG/L P
0.273
0.380
0.790
0.420
0.500
0.690
3.230
0.850
0.850
0.756
0.570
0.740
0.400
MG/L P
0.540
0.700
1.000
0.600
0.660
0.850
1.100
1.050
0.960
0.970
0.940
0.700
-------
STORE! RETRIEVAL DATE 75/10/16
1008B1
39 26 00.0 075 42 30.0
UNNAMED STREAM
10 7.5 MIDDLETOMN
T/SILVER LAKE
ST HWY 71 8RDG 0.75 MI S OF MIDDLETOWN
11EPALES 2111204
4 0000 FEET DEPTH
00630 00625
DATE TIME DEPTH N02&N03 TOT KJEL
FROM OF N-TOTAL N
TO DAY FEET
73/04/28 08 50
73/05/20 12 55
73/06/25 12 40
73/07/23 09 15
73/08/20 10 10
73/09/16 16 10
73/10/28 14 35
73/11/16 15 10
73/12/04 09 20
74/01/08 13 35
74/02/05 15 30
74/03/11 09 20
74/03/22 10 00
MG/L
6.100
7.150
8.000
7.600
7.350
8.500
7.900
8.400
8.300
8.500
2.800
7.300
MG/L
1.100
0.150
0.100K
1.500
0.100K
0.100K
0.100K
0.500
0.100
0.700
0.600
00610 00671 00665
NH3-N PHOS-DIS PHOS-TOT
TOTAL ORTHO
MG/L
0.126
0.113
0.076
0.052
0.069
0.069
0.059
0.044
0.048
0.065
0.030
0.180
0.110
MG/L P
0.033
0.012
0.014
0.022
0.032
0.024
0.017
0.020
0.016
0.015
0.007
0.030
0.015
MG/L P
0.095
0.050
0.040
0.040
0.050
0.047
0.060
0.040
0.020
0.025
0.020
0.065
0.060
K VALUE KNOWN TO BE
LESS THAN INDICATED
-------
STORET RETRIEVAL DATE 75/10/16
1009A1
38 38 30.0 075 36 30.0
CLEAR CREEK-WILLIAMS POND OUTLET
10 7.5 SEAFORO EAST
O/WILLIAMS POND
BRDG IN EASTERN EDGE OF SEAFORD
11EPALES 2111204
4 0000 FEET DEPTH
DATE
FROM
TO
73/04/28
73/05/20
73/06/23
73/07/22
73/08/18
73/09/23
73/10/28
73/11/10
73/12/01
74/01/05
74/02/05
74/03/09
74/03/25
00630 00625
TIME DEPTH N02&N03 TOT KJEL
OF N-TOTAL N
DAY FEET
11
09
09
08
09
13
09
10
09
09
12
10
01
00
50
30
40
10
00
45
10
25
15
00
MG/L
2
1
0
0
1
1
1
1
3
4
3
2
.200
.420
.360
.069
.800
.360
.360
.760
.200
.000
.200
.800
MG/L
0.
0.
0.
480
890
690
1.000
1.
0.
0.
0.
0.
0.
0.
0.
0.
320
940
700
575
400
500
400
800
700
00610 00671 00665
NH3-N PHOS-DIS PHOS-TOT
TOTAL ORTHO
MG/L
0.048
0.032
0.048
0.013
0.019
0.098
0.044
0.028
0.032
0.064
0.057
0.035
0.020
MG/L
0
0
0
0
0
0
0
0
0
0
0
0
0
•
•
•
•
•
•
•
•
•
*
•
•
•
P
Oil
008
008
012
023
010
012
Oil
008
024
020
010
015
MG/L P
0.040
0.035
0.030
0.075
0.095
0.055
0.060
0.032
0.040
0.045
0.020
0.025
0.035
-------
STORE! RETRIEVAL DATE 75/10/16
1008BA TF10088A P002644»
39 26 45.0 075 42 15.0
MIDDLETOirfN
10 7.5 MIDDLETOteN
T/SILVER LAKE
APPOOUINIMINK RIVER
11EPALES 2141204
4 0000 FEET DEPTH
DATE
FROM
TO
73/06/05
CP(T)-
73/06/05
CP(T)-
73/06/06
73/07/12
CP < T ) -
73/07/13
73/08/09
cpm-
73/08/10
73/09/19
cpm-
73/09/20
73/10/09
CP(T>-
73/10/10
73/11/14
cpm-
73/11/15
73/12/12
CP
-------