U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EUTROPHICATION SURVEY
WORKING PAPER SERIES
REPORT
ON
UPPER AND LOWER 1WN U\KES
KOOTENAI COUNTY
IDAHO
EPA REGION X
WORKING PAPER No, 787
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON
and
ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA
-------
REPORT
ON
UPPER AND LOWER TWIN LAKES
KDOTENAI COUNTY
IDAHO
EPA REGION X
WORKING PAPER No, 787
WITH THE COOPERATION OF THE
IDAHO DEPARTMENT OF HEALTH AND WELFARE
AND THE
IDAHO NATIONAL GUARD
JULY, 1977
-------
REPORT ON UPPER AND LOWER TWIN LAKES
KOOTENAI COUNTY, IDAHO
EPA REGION X
by
National Eutrophication Survey
Water and Land Quality Branch
Monitoring Operations Division
Environmental Monitoring & Support Laboratory
Las Vegas, Nevada
and
Special Studies Branch
Corvallis Environmental Research Laboratory
Corvallis, Oregon
Working Paper No. 787
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
July 1977
-------
CONTENTS
Page
Foreword i j
List of Idaho Study Lakes iv
Lake and Drainage Area Map v
Sections
I. Conclusions 1
II. Lake and Drainage Basin Characteristics 3
III. Lake Water Quality Summary 5
IV. Nutrient Loadings 16
V. Literature Reviewed 21
VI. Appendices 22
-------
11
FOREWORD
The National Eutrophicatlon Survey was Initiated 1n 1972 in
response to an Administration commitment to Investigate the nation-
wide threat of accelerated eutrophicatlon to freshwater lakes and
reservoirs.
OBJECTIVES
The Survey was designed to develop, in conjunction with state
environmental agencies, information on nutrient sources, concen-
trations, and impact on selected freshwater lakes as a basis for
formulating comprehensive and coordinated national, regional, and
state management practices relating to point source discharge
reduction and nonpolnt source pollution abatement in lake water-
sheds.
ANALYTIC APPROACH
The mathematical and statistical procedures selected for the
Survey's eutrophicatlon analysis are based on related concepts
that:
a. A generalized representation or model relating
sources, concentrations, and Impacts can be
constructed.
b. By applying measurements of relevant parameters
associated with lake degradation, the generalized
model can be transformed Into an operational
representation of a lake, its drainage basin, and
related nutrients.
c. With such a transformation, an assessment of the
potential for eutrophication control can be made.
LAKE ANALYSIS
In this report, the first stage of evaluation of lake and
watershed data collected from the study lake and its drainage
basin is documented. The report is formatted to provide state
environmental agencies with specific Information for basin
planninq [§303(e)], water quality criteria/standards review
[§303(c)], clean lakes [§314(a,bJ], and water quality monitoring
[§106 and §305(b)] activities mandated by the Federal Water
Pollution Control Act Amendments of 1972.
-------
111
Beyond the single lake analysis, broader based correlations
between nutrient concentrations (and loading) and trophic condition
are being made to advance the rationale and data base for refine-
ment of nutrient water quality criteria for the Nation's freshwater
lakes. Likewise, multivariate evaluations for the relationships
between land use, nutrient export, and trophic condition, by lake
class or use, are being developed to assist in the formulation of
planning guidelines and policies by the U.S. Environmental Protection
Agency and to augment plans implementation by the states.
ACKNOWLEDGMENTS
The staff of the National Eutrophication Survey (Office of
Research and Development, U.S. Environmental Protection Agency)
expresses sincere appreciation to the Idaho Department of Health
and Welfare for professional involvement, to the Idaho National
Guard for conducting the tributary sampling phase of the Survey,
and to those Idaho wastewater treatment plant operators who pro-
vided effluent samples and flow data.
The staff of the State of Idaho Department of Health and
Welfare, Division of Environment, provided invaluable lake docu-
mentation and counsel during the Survey, reviewed the preliminary
reports and provided critiques most useful in the preparation of
this Working Paper Series.
Major General James S. Brooks, Adjutant General of Idaho, and
Project Officer Major Vestal L. Baker, who directed the volunteer
efforts of the Idaho National Guardsmen, are also gratefully
acknowledged for their assistance to the Survey.
-------
NATIONAL EUTROPHICATION SURVEY
STUDY LAKES
STATE OF IDAHO
LAKE NAME
American Falls Reservoir
Cascade Reservoir
Coeur d'Alene Lake
Dworshak Reservoir
Hauser Lake
Hayden Lake
Island Park Reservoir
Lake Lowell (Deer Flat Reservoir)
Magic Reservoir
Palisades Reservoir
Payette Lake
Lower Twin Lake
Upper Twin Lake
COUNTY
Bannock, Bingham, Power
Valley
Benewah, Kootenai
Clearwater
Kootenai
Kootenai
Fremont
Canyon
Blaine, Camas
Bonneville (Lincoln in WY)
Valley
Kootenai
Kootenai
-------
n
Ida.
Map Location
®
X
Q
0
1
0
TWIN LAKES
Tributar" Samrilinri Site
Lake Sampling Site
Drainage Area Boundary
1234 S^TO-
i i i i i
i i i
1 2 3 Mi ^
Scale
V
r
(
i
Silvej^Sands Beach
e*>Echo Beach
.Twinlow
4755
/
-------
REPORT ON UPPER AND LOWER TWIN LAKES, IDAHO
STORET NO.'s 1612-1613
I. CONCLUSIONS
A. Trophic Condition:*
Based upon field observations and Survey data, Twin Lakes
is considered eutrophic. Chlorophyll a^ values in the lake ranged
from 1.1 yg/1 to 19.4 yg/1 with a mean of 2.3 yg/1 in the lower
basin and 5.0 yg/1 in the upper basin. Nutrient levels and
potential for primary production as measured by algal assay control
yield were low, but aquatic weed problems and algal blooms indi-
cate lake degradation. Secchi disc visibility was quite high
in the lake throughout the sampling year.
Field limnologists reported abundant submerged macrophytes
along the entire lake bottom; the low phosphorus values in Twin
Lakes probably result from phosphorus tied up in these macrophytes.
Limnologists also noted algal blooms throughout the lake in July
and water lilies in the narrows separating the upper and lower
basins. The Idaho Department of Water Resources et al. (1975)
report that enriched conditions in Twin Lakes are primarily due
to irrigation runoff, feedlots and residential development around
the lake.
lVSee Appendix E.
-------
B. Rate-Limiting Nutrient:
The algal assay results indicate that Upper and Lower Twin Lakes
was limited by available phosphorus levels during the sampling year.
The lake data generally suggest primary limitation by nitrogen through-
out the sampling year.
C. Nutrient Controllability:
1. Point sources -
During the sampling year there were no known point sources
impacting Upper and Lower Twin Lakes.
2
The calculated annual phosphorus loading of 0.12 g P/m /yr
is equal to that proposed by Vollenweider as a "oligotrophic"
loading for lakes with such volume and hydraulic retention time;
however, sharp chemical and temperature stratification combined
with lengthy detention time could contribute to nutrient buildup
and potential for internal recycling. As there are no known
avert pollutant sources to the lake, much of the organic load
impacting the hypolimnetic dissolved oxygen is presumably from
macrophyte decomposition. An aquatic weed control program could
be considered for these waters.
Further information about the land uses and watershed
surrounding Twin Lakes is needed before additional recommendations
for lake improvements can be proposed.
-------
II. LAKE AND DRAINAGE BASIN CHARACTERISTICS
Lake and drainage basin characteristics are itemized below.
Lake surface area, mean depth and volume were provided by Martin and
Hanson (1966). Maximum depth was estimated on the basis of National
Eutrophication Survey (NES) sampling data. Tributary flow data were
provided by the Idaho District Office of the U.S. Geological Survey
(USGS). 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 NES Working Paper No. 175. A
table of metric/English conversions is included as Appendix A.
A. Lake Morphometry:
2
1. Surface area: 16.35 km .
2. Mean depth: 2.3 meters.
3. Maximum depth: 18.3 meters.
4. Volume: 38.534 x 106 m3.
5. Mean hydraulic retention time: 676 days (1.8 yr).
-------
B. Tributary and Outlet:
(See Appendix B for flow data)
1. Tributaries -
Drainage Mean flow
Name area (km?) (m3/sec)
C-l Shove Creek 6.6 0.11
D-l Fish Creek 37.8 0.61
Minor tributaries and
immediate drainage - 72.4 1.42
Totals ' 116.8 2.14
2. Outlet - A-l Rathdrum Creek 133.4 0.66
C. Precipitation:
1. Year of sampling: 86.1 cm.
2. Mean annual: 84.2 cm.
-------
III. LAKE WATER QUALITY SUMMARY
Upper and Lower Twin Lakes was sampled four times during the
open-water season of 1975 by means of a pontoon-equipped Huey heli-
copter. Each time, samples for physical and chemical parameters were
collected from a total of five stations on the lake and from a number
of depths at each station (see map, page v). During each visit,
depth-integrated samples were collected from each station for chloro-
phyll a_ analysis and phytoplankton identification and enumeration.
During the first and last visits, 18.9-liter depth-integrated samples
were composited for algal assays. Maximum depths sampled were 3.4
meters at Station 01, -17.1 meters at Station 02, and 1.5 meters at
Station 03 (Lower Twin Lakes); and 3.4 meters at Station 01, and
4.0 meters at Station 02 (Upper Twin Lakes). For a more detailed
explanation of NES methods, see NES Working Paper No. 175.
The results obtained are presented in full in Appendix C and are
summarized in III-A for waters at the surface and at the maximum
depth for each site. Results of the phytoplankton counts and chloro-
phyll a determinations are included in III-B. Results of the limiting
nutrient study are presented in III-C.
-------
STORET CODE 161?
PARAMETER
N*
PHYSICAL AND CHEMICAL CHARACTERISTICo
( 6/ 3/75 ) ( 7/23/75 )
MAX MAX
S»o» = t DEPTH S»»* = 3 DEPTH
^ANGF RANGE
RANGE MEDIAN (METEHS) N* RANGE MEDIAN (METERS)
N*
( 9/10/75 )
MAX
S«»« = 3 DEPTH
RANGE
RANGE MEDIAN (METERS)
TEMPERATURE (DEG CENT)
0.-1.5 M DEPTH
MAX DEPTH»»
DISSOLVED OXYGEN
0.-1.5 * DEPTH
MAX DEPTH**
CONDUCTIVITY UIMHO
0.-1.5 M DEPTH
MAX DEPTH**
PH (STANDARD UNITS)
O.-l.S 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
MAX DEPTH**
N02+N03 (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
AMMONIA (MG/D
O.-l.S M DEPTH
MAX DEPTH**
KJELDAHL N (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
SECCHI DISC (METERS)
6
3
(MG/L)
6
3
0«>
6
3
S)
ft
3
(MG/L)
6
3
6
3
(MG/L)
6
3
6
3
6
3
6
3
13.7- 15.8
5.6- 15.5
8.8- 9.6
8.0- 9.0
22.- 23.
20.- 23.
7.3- 8.0
8.0- 8.2
14.- 21.
12.- 21.
0.012-0.018
0.012-0.018
0.007-0.014
0.007-0.009
0.020-0.020
0.020-0.020
0.030-0.040
0.030-0.040
0.200-0.400
0.300-0.400
14.9
13. r
9.0
B.8
23.
23.
7.8
8.2
15.
IP.
0.016
0.016
0.011
0.007
0.0?0
0.020
0.035
0.040
0.350
0.300
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1 .5-
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
0.0-
1.5-
1.5
14.6
1.5
14.6
1.5
14.6
1.5
14.6
1.5
14.6
1.5
14.6
1.5 .
14.6
1.5
14.6
1.5
14.6
1.5
14.6
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
6
3
23.9- 25.5
8.0- 25.3
8.2- 9.6
7.6- 8.8
19.- 25.
17.- 25.
7.0- 7.8
6.7- 7.4
13.- 24.
14.- 33.
0.013-0.018
0.015-0.022
0.009-0.013
0.009-0.012
0.020-0.020
0.020-0.020
0.020-0.060
0.020-0.040
0.200-0.800
0.200-0.400
24.6
23.7
8.7
8.8
33.
22.
7.3
7.2
23.
18.
0.015
0.016
0.009
0.009
0.020
0.020
0 . 035
0.030
0.400
0.300
0.0-
1.3-
0.0-
1.2-
0.0-
1.2-
0.0-
1.2-
0.0-
1.3-
0.0-
1.2-
0.0-
1.2-
0.0-
1.2-
0.0-
1.3-
0.0-
1.2-
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
1.5
14.0
5
3
5
3
5
3
5
3
5
3
5
3
5
3
5
3
5
3
5
3
14.3- 15.4
3.6- 15.4
8.6- 9.8
1.8- 9. ft
10.- 18.
9.- 18.
7.5- 8.1
7.0- 7.9
10.- 26.
13.- 25.
0.012-0.422
0.008-n.*23
0.003-0.012
0.003-0.012
0.020-0.020
0.030-0.030
0.030-0.030
0.020-0.020
0.300-1.600
0.200-1.600
14.5
14.4
9.0
9.0
14.
14.
7.8
7.8
17.
15.
0.015
0.014
0.002
0.002
0.030
0.020
0.030
0.030
0.400
0.400
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-
0.0-
0.0-
0.0-
0.0-
0.0-
0.0-
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
1.5
13.7
. 1.5
13.7
3.2- 4.9
4.0
3.7- 3.7
3.7
1.8- 3.7
3.0
* N = NO. OF SAMPLES
** MAXIMUM DEPTH SAMPLED AT EACH SITE
s = NO. OF SITES SAMPLED ON THIS DATE
-------
LOWER TWIN LAKES
STOP.ET CODE 1M2
PHYSICAL AMD CHEMICAL CHARACTERISTICS
PARAMETER
TEMPERATURE (DEG CFfjT
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN (<*G/
0.-1.5 M DEPTH
MAX DEPTH**
CONDUCTIVITY (IJMHOS)
0.-1.5 M DEPTH
MAX DEPTH**
PH (STANDARD UNITS)
0.-1.5 M DEPTH
MAX DEPTH**
N*
)
6
3
'D
5
2
6
3
6
3
TOTAL ALKALINITY (MG/L)
0.-1.5 M DEPTH 6
MAX DEPTH** 3
TOTAL P (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
6
3
DISSOLVED ORTHO P (MG/L)
0.-1.5 M DEPTH 6
MAX DEPTH** 3
N02*N03 (MG/L)
O.-l.S M OEPTH
MAX DEPTH**
AMMONIA (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
KJELDAHL N (MG/L)
0.-1.5 M nEPTH
MAX DEPTH**
6
3
6
3
6
3
( 10/24/75
S*«* = 1
RANGE MEDIAN
9.3- 11.3
8.1- 10.0
8.2- 9.2
1.4- 9.2
34.- 25.
23.- 32.
6.7- 7.1
6.4- 7.1
10.- 16.
10.- 10.
0.013-0.049
0.015-0.206
0.002-0.018
0.002-0.149
0.020-0.020
0.020-0.020
0.020-0.030
0.020-0.280
0.200-0.500
0.200-0.400
10.4
9.3
R.6
5.3
24.
24.
7.0
6.8
10.
in.
0.016
0.020
0.003
0.003
0.020
0.020
0.020
0.020
0.200
0.400
)
MAX
OEPTH
RANGF
(METERS)
0.0- 1.5
1.5- 17.1
0.0- 1.5
3.0- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
0.0- 1.5
1.5- 17.1
SECCHI DISC (METERS)
2.4- 4.0
3.0
» N = NO. OF SAMPLES
** MAXIMUM DEPTH SAMPLED AT EACH SITE
*»» 5 = NO. OF SITES SAMPLED ON THIS DATE
-------
UPPER TWIN LAKES
STORET CODE 1613
( 6/ 3/75 )
PHYSICAL AND CHEMICAL CHARACTERISTICS
( 7/23/75 )
PARAMETER
TEMPERATURE (DEG
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN
0.-1.5 M DEPTH
MAX DEPTH**
N*
CFNT)
4
2
(MG/L)
4
2
RANGE
14.6- 15.2
9.8- 12.4
8.8- 10.0
8.8- 9.2
MEDIAN
14.9
11.1
8.9
9.0
MAX
DEPTH
RANGE
(METERS)
0.0-
3.4-
0.0-
3.4-
1.5
4.6
1.5
4.6
N*
3
2
3
2
S**«
RANGE
21.5- 22.2
19.3- 20.4
6.8- 9.6
9.8- 10.2
= 2
MEDIAN
22.0
19.8
9.2
10.0
MAX
DEPTH
RANGE
(METERS)
0.0-
2.4-
0.0-
2.4-
1.5
4.0
1.5
4.0
N*
4
2
4
2
S«»«
RANGE
15.1- 16.2
14.3- 15.1
8.6- 9.6
9.6- 9.6
= 2
MEDIAN
15.7
14.7
9.4
9.6
MAX
DEPTH
RANGE
(METERS)
0.0- 1.5
2.7- 3.7
0.0- 1.5
3.7- 3.7
CONDUCTIVITY (UMHO^)
0.-1.5 M DEPTH
MAX DEPTH**
4
2
20.- 22.
18.- 20.
22.
19.
0.0-
3.4-
1.5
4.6
3
2
14.- 22.
19.- 21.
21.
20.
0.0-
2.4-
1.5
4.0
4
2
14.- 19.
16.- 16.
16.
16.
0.0- 1.5
3.7- 3.7
PH (STANDARD UNITS)
0.-1.5 M DEPTH
TOTAL ALKALINITY
0.-1.5 M DEPTH
MAX DEPTH**
TOTAL P (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED ORTHO p
O.-l.S M DEPTH
MAX DEPTH**
N02+N03 (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
AMMONIA (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
KJELOAHL N (MG/L)
O.-l.S M DEPTH
MAX DEPTH**
4
(MG/L)
4
2
4
2
(MG/L)
4
2
4
2
4
2
4
2
7.4- 8.0
10.- 17.
10.- 15.
0.016-0.019
0. 016-0. 018
0.007-0.017
0.012-0.014
0.020-0.020
0.020-0.020
0.040-0.100
0.030-0.040
0.400-0.600
0.300-0.300
7.8
15.
13.
0.017
0.017
0.013
0.013
0.0?0
O.OPO
0.045
0.035
0.400
0.300
0.0-
34
• *r ~
0.0-
3.4-
0.0-
3.4-
0.0-
3.4-
0.0-
3.4-
0.0-
3.4-
0.0-
3.4-
1.5
/. f.
f • r>
1.5
4.6
1.5
4.6
1.5
4.6
1.5
4.6
1.5
4.6
1.5
4.6
3
3
2
3
2
3
2
3
2
3
2
3
2
7.6- 8.0
7o— a 7
• O*" O • f
19.- 21.
19.- 22.
0.014-0.015
0.015-0.021
0.004-0.011
0.009-0.014
0.020-0.020
0.020-0.020
0.040-0.060
0.020-0.040
0.400-0.600
0.300-0.400
7.8
8 -a
• J
20.
21.
0.014
0.018
0.009
0.011
0.020
0.020
0.040
0.030
0.600
0.350
0.0-
2 A _
. 4 —
0.0-
2.4-
0.0-
2.4-
0.0-
2.4-
0.0-
2.4-
0.0-
2.4-
0.0-
2.4-
1.5
/. A
*r • 0
1.5
4.0
1.5
4.0
1.5
4.0
1.5
4.0
1.5
4.0
1.5
4.0
4
4
2
4
2
4
2
4
2
4
2
4
2
7.6- 8.5
8O_ Q ^
. J— 8. J
12.- 14.
11.- 16.
0.016-0.024
0.016-0.069
0.002-0.003
0.002-0.002
0.020-0.020
0.020-0.020
0.020-0.030
0.020-0.030
0.400-0.400
0.400-0.600
8.3
8^
• J
13.
14.
0.020
0.042
0.002
0.002
0.020
0.030
0.020
0.030
0.400
0.500
0.0- 1.5
2 "7 ^ 7
. f — J. '
0.0- 1.5
3.7- 3.7
0.0- 1.5
2.7- 3.7
0.0- 1.5
3.7- 3.7
0.0- 1.5
3.7- 3.7
0.0- 1.5
3.7- 3.7
0.0- 1.5
3.7- 3.7
SECCHI DISC (METERS)
3.0- 3.2
3.1
4.6- 4.6
4.6
2.4- 3.7
3.0
» N = NO. OF SAMPLES
«* MAXIMUM DEPTH SAMPLED AT EACH SITE
«*» S = NO. OF SITES SAMPLED ON THIS DATE
-------
UPPER TWIN LAKES
STORE! CODE 1613
PHYSICAL AMD CHEMICAL CHARACTERISTICS
( 10/24/75 )
PARAMETER
TEMPERATURE (DEC CENT)
0.-1.5 M DEPTH
MAX DEPTH**
DISSOLVED OXYGEN (MG/L
0.-1.5 M OEPTH
MAX DEPTH**
CONDUCTIVITY (UMHO?)
0.-1.5 M OEPTH
MAX DEPTH**
PH (STANDARD UNITS)
0.-1.5 M DEPTH
MAX DEPTH**
TOTAL ALKALINITY (MG/L
0.-1.5 M OEPTH
MAX DEPTH**
TOTAL P (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
S**«
KJ» u«NGE
4
2
i
4
2
4
2
4
2
)
4
2
4
2
3.3-
8.8-
9.4-
9.4-
20.-
20.-
6.9-
7.0-
10.-
10.-
0.014-0
0.018-0
10.1
9.9
10.0
9.8
24.
24.
7.3
7.3
18.
18.
.019
.019
= 2
MEDIAN
9.6
9.3
9.7
9.6
22.
22.
7.1
7.1
10.
14.
0.016
o.oie
MAX
OEPTH
RANGE
(METER":;)
0
1
0
1
0
1
0
1
0
1
0
1
.0-
.5-
.0-
.5-
.0-
.5-
.0-
.5-
.0-
.5-
.0-
.5-
1.5
3.0
1.5
3.0
1.5
3.0
1.5
3.0
1.5
3.0
1.5
3.0
DISSOLVED ORTHO P (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
N02+N03 (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
AMMONIA (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
KJELDAHL N (MG/L)
0.-1.5 M DEPTH
MAX DEPTH**
4
2
4
2
4
2
4
2
0.002-0
0.002-0
0.020-0
0.020-0
0.020-0
0.020-0
0.200-0
0.200-0
.005
.005
.020
.020
.020
.020
.400
.300
0.002
0.0f>3
0.0?0
0.020
0.020
0.020
0.300
0.250
0
1
0
1
0
1
0
1
.0-
.5-
.0-
.5-
.0-
.5-
.0-
.5-
1.5
3.0
1.5
3.0
1.5
3.0
1.5
3.0.
SECCHI DISC (METERS)
3.1- 3.2
3.2
* N = NO. OF SAMPLES
«» MAXIMUM DEPTH SAMPLED AT EACH SITE
«»» s = NO. OF SITES SAMPLED ON THIS DATE
-------
10
B. Biological Characteristics:
1. Phytoplankton - Lower Twin Lakes
Sampling
Date
06/03/75
07/23/75
09/10/75
10/24/75
Dominant
Genera
1. Dinobryon
2. Asterionella
3. Flagellate
4. Anabaena
5. Nitzschia
Other genera
Total
1. Melosira
2. Fragilaria
3. Ankistrodesmus
4. Asterionella
5. Chlorophytan cell
Other genera
Total
1. Merismopedia
2. Chroomonas
3. Melosira
4. Cryptomonas
5. Oocystis
Other genera
Total
1. Ankistrodesmus
2. Cryptomonas
3. Chroomonas
4. Tabellaria
Other genera
Total
Algal
Units
per ml
1,214
187
140
47
47
45_
1,680
875
175
131
87
87
176
1,531
3,081
171
171
128
86
129
3,766
128
128
43
43
342
-------
11
B. Biological Characteristics: (continued)
1. Phytoplankton - Upper Twin Lakes
Sampling
Date
06/03/75
07/23/75
09/10/75
10/24/75
Dominant
Genera
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
Dinobryon
Chroomonas
Ankistrodesmus
Asterionella
Cryptomonas
Other genera
Total
Cryptomonas
Chroomonas
Stichococcus
Chroococcus
Coelosphaerium
Other genera
Total
Melosira
Fragilaria
Epithemia
Lyngbya
Ankistrodesmus
Other genera
Total
1. Flagellate
2. Cryptomonas
3. Chroomonas
4. Chlamydomonas
5. Mallomonas
Other genera
Total
Algal
Units
per ml
788
338
113
113
113
167
1,632
291
97
97
48
48
581
932
883
343
294
196
1.769
4,417
1,200
768
432
144
144
47_
2,735
-------
12
2. Chlorophyll a. -
Sampling Station Chlorophyll
Date Number (yg/1)
06/03/75 01 (Lower Twin) 1.7
02 1.1
03 1.2
01 (Upper Twin) 2.5
02 2.4
07/23/75 01 2.9
02 3.7
03 2.0
01 1.9
02 3.4
09/10/75 01 3.7
02 2.5
03
01 19.4
02 ----
10/24/75 01 2.8
02 2.5
03 1.4
01 2.5
02 2.8
-------
13
C. Limiting Nutrient Study:
1. Autoclaved, filtered, and nutrient spiked -
a. 06/03/75 (Lower Twin Lakes)
Spike (mq/1)
Ortho P
Cone, (mg/1)
Inorganic N
Cone, (mg/1)
Maximum Yield
(mg/1-dry wt.)
Control
0.05 P
0.05 P + 1.0 N
1.00 N
b. 09/10/75
Spike (mg/1)
Control
0.05 P
0.05 P + 1.0 N
1.00 N
c. 10/24/75
Spike (mg/1)
Control
0,05 P
0.05 P + 1.0 N
1.00 N
<0.005
<0.055
<0.055
<0.005
Ortho P
Cone, (mg/1)
0.010
0.060
0.060
0.010
Ortho P
Cone, (mg/1)
0.010
0.060
0.060
0.010
0.025
0.025
1.025
1.025
Inorganic N
Cone, (mg/1)
0.035
0.035
1.035
1.035
Inorganic N
Cone, (mg/1)
0.050
0.050
1.050
1.050
0.4
1.4
17.4
0.5
Maximum Yield
(mg/1 -dry wt. )
0.9
5.6
18.8
0.8
Maximum Yield
(mg/1 -dry wt. )
0.7
3.9
21.2
0.7
-------
14
C. Limiting Nutrient Study (continued) -
1. Autoclaved, filtered, and nutrient spiked -
d. 06/03/75 (Upper Twin Lakes)
Spike (mg/1)
Ortho P
Cone, (mg/1)
Control <0.005
0.05 P <0.055
0.05 P + 1.0 N <0.055
1.00 N <0.005
e.
09/10/75
Spike (mg/1)
Control
0.05 P
0.05 P + 1.0 N
1.00 N
f. 10/24/75
Ortho P
Cone, (mg/1)
0.025
0.075
0.075
0.025
Ortho P
Spike (mg/1) Cone, (mg/1)
Control 0.005
0.05 P 0.055
0.05 P + 1.0 N 0.055
1.00 N 0.005
Inorganic N
Cone, (mg/1)
0.025
0.025
1.025
1.025
Inorganic N
Cone, (mg/1)
0.150
0.150
1.150
1.150
Inorganic N
Cone, (mg/1)
0.045
0.045
1.045
1.045
Maximum Yield
(mg/1-dry wt.)
0.3
1.7
17.6
0.3
Maximum Yield
(mg/1-dry wt.)
2.1
9.0
24.4
2.1
Maximum Yield
(mg/l-dry wt.)
0.6
4.0
25.6
0.5
-------
15
2. Discussion -
The control yields of the assay alga, Selenastrum capri-
cornutum, indicate that the potential for primary productivity was
moderate in Upper and Lower Twin Lakes except during September samp-
ling when it was high in Upper Twin Lakes. In all assays, there
was significant increase in yield over that of the control when
orthophosphorus was added indicating phosphorus limitation. The
addition of nitrogen alone did not result in an increase in yield,
and the maximum growth increase over that of the control was achieved
with the simultaneous addition of both nitrogen and phosphorus.
Mean inorganic nitrogen to orthophosphorus ratios N/P in the
lake data were approximately 6/1 in Lower Twin Lakes for all sampling
rounds suggesting nitrogen limitation at those times. In Upper Twin
Lakes, the N/P ratios of approximately 5/1 and 6/1 in June and August
suggest nitrogen limitation, while the approximate ratios of 21/1 and
13/1 in September and October suggest phosphorus limitation and co-
limitation by the two nutrients, respectively, on those sampling
occasions.
-------
16
IV. NUTRIENT LOADINGS
(See Appendix D for data)
For the determination of nutrient loadings, the Idaho 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 July when two samples were collected. Sampling was
begun in October 1974, and was completed in September 1975.
Through an interagency agreement, stream flow estimates for the
year of sampling and a "normalized" or average year were provided by
the Idaho 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 a 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
2
nutrient loads, in kg/km /year, in Shove Creek and Fish Creek at
2
Stations C-l and D-l and multiplying the means by the ZZ area in km .
-------
17
A. Waste Sources:
1. Known municipal - None
2. Known industrial - None
B. Annual Total Phosphorus Loading - Average Year:
1. Inputs -
% of
Source kg P/yr total
a. Tributaries (nonpoint load) -
C-l Shove Creek 55 2.9
D-l Fish Creek 580 30.4
b. Minor tributaries and immediate
drainage (nonpoint load) - 870 45.5
c. Known municipal STP's - None
d. Septic tanks* - 120 6.3
e. Known industrial - None
f. Direct precipitation** - 285 14.9
Totals 1,910 100.0%
2. Outputs - A-l Rathdrum Creek 235
3. Net annual P accumulation - 1,675
*Estimate based on 419 lakeshore residences.
**Estimated (See NES Working Paper No. 175).
-------
18
C. Annual Total Nitrogen Loading - Average Year:
1. Inputs -
% of
Source kg N/yr total
a. Tributaries (nonpoint load) -
C-l Shove Creek 1,970 3.8
D-l Fish Creek 8,590 16.6
b. Minor tributaries and immediate
drainage (nonpoint load) - 18,970 36.8
c. Known municipal STP's - None
d. Septic tanks* - 4,465 8.6
e. Known industrial - None
f. Direct precipitation** - 17.650 34.2
Totals 51,645 100.0%
2. Outputs - A-l Rathdrum Creek 7,610
3. Net annual N accumulation - 44,035
*Estimate based on 419 lakeshore residences.
**Estimated (See NES Working Paper No. 175).
-------
19
D. Mean Annual Nonpoint Nutrient Export by Subdrainage Area:
2 2
Tributary kg P/km /yr kg N/km /yr
Shove Creek 8 298
Fish Creek 15 227
E. Mean Nutrient Concentrations in Ungaged Streams:
Mean Total P Mean Total N
Tributary (mg/1) (mg/1)
B-l Unnamed Stream 0.037 0.570
-------
20
E. Yearly Loadings:
In the following table, the existing phosphorus loading is
compared to the realtionship proposed by Vollenweider (1975). Essen-
tially, his "eutrophic" loading is that at which the receiving waters
would become eutrophic or remain eutrophic; his "oligotrophic"
loading is that which would result in the receiving water remaining
oligotrophic or becoming oligotrophic if morphometry permitted. A
"mesotrophic" loading would be considered one between "dangerous"
and "permissible."
Note that Vollenweider's model may not be applicable to water
bodies with very short retention times or in which light penetration
is severely restricted from high concentrations of suspended solids
in the surface waters.
Total Yearly
Phosphorus Loading
(g/m2/yr)
Estimated loading for Upper and Lower Twin Lakes 0.12
Vollenweider's "eutrophic" loading 0.22
Vollenweider's "oligotrophic" loading 0.11
-------
21
V. LITERATURE REVIEWED
Idaho Department of Water Resources, Department of Health and Welfare,
Department of Fish and Game, and Department of Budget, Policy
Planning and Coordination. 1975. Idaho Environmental Overview.
Boise, Idaho.
Martin, R.O.R. and Ronald L. Hanson, 1966. Reservoirs in the U.S.
Geological Survey Water Supply Paper 1838. U.S. Government Printing
Office, Washington, D.C.
U.S. Environmental Protection Agency. 1975. National Eutrophica-
tion Survey Methods 1973-1976. Working Paper No. 175. National
Environmental Research Center, Las Vegas, Nevada, and Pacific
Northwest Environmental Research Laboratory, Con/all is, Oregon.
Vollenweider, R. A. 1975. Input-Output Models With Special
Reference to the Phosphorus Loading Concept in Limnology.
Schweiz. Z. Hydro!. 37:53-84.
-------
22
VI. APPENDICES
APPENDIX A
CONVERSION FACTORS
-------
CONVERSION FACTORS
Hectares x 2.471 = acres
Kilometers x 0.6214 = miles
Meters x 3.281 = feet
Cubic meters x 8.107 x 10" = 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/s.quarc kilometer x 5.711 ~ Ibs/square mile
-------
APPENDIX B
TRIBUTARY FLOW DATA
-------
TRIBUTARY FLOW INFORMATION FOR IDAHO
LAKF CODE 1618 TWIN LAKFS
TOTAL DRAINAGE APEA OF LAKFtSQ KM) 133.*
OP/23/76
TRIBUTARY AREAfSQ KM)
JAN
FF.B
MAP
APR
MAY
NORMALIZED FLOWS(CMS)
JUN JUL AU6
SEP
OCT
NOV
DEC
MEAN
1612A)
1612C1
161201
161277
133.4
6.6
37.8
88.8
0.57
0.113
0.57
1.42
0.74
0.142
0.88
1.98
n.96
0.255
1.39
3.34
1.70
0.2S3
1.56
3.71
i.n
0.19S
1.19
2.72
0.68
0.085
0.48
1.13
0.68
0.028
0.23
0.45
0.62
0.028
0.14
0.37
0.31
0.028
0.14
0.37
0.11
0.028
0.17
0.40
0.17
0.028
0.?3
0.45
0.31
0.057
0.34
0.79
0.66
0.106
0.61
1.42
SUMMARY
TOTAL DRAINAGE AREA OF LAKE = 133.4
SUM OF SUB-DRAINAGE AREAS = 133.3
TOTAL FLOW IN
TOTAL FLOW OUT
25.71
7.99
MEAN MONTHLY FLOWS AND DAILY FLOWSCCMSI
TRIBUTARY
1612A1
MONTH
YEAR
1612C1
in
11
12
l
?.
3
4
5
6
7
a
9
10
11
12
1
2
3
4
5
6
7
8
9
74
74
74
75
75
75
75
75
75
75
75
75
74
74
74
75
75
75
75
75
75
75
75
75
FLOW
0.072
0.113
0.196
0.507
0.906
1.356
1.484
4.332
0.988
0.467
0.368
0.230
0.017
0.028
0.028
0.037
0.051
0.133
0.261
0.368
0.122
0.048
0.031
0.025
DAY
19
18
16
18
16
16
13
16
7
c;
B
19
18
16
1R
16
16
n
16
7
t;
fl
FLOW DAY
0.071
0.113
0.130
0.580
0.510
0.864
0.255
5.097
1.416
0.566 8
0.396
0.017
0.037
0.023
0.079
0.062
0.108
0.156
0.481
0.150
0.057 8
0.028
FLOW DAY
FLOW
0.566
28
0.425
0.051
28
0.037
-------
TRIBUTARY FLOW INFORMATION FOH IDAHO
Ofl/?3/76
LAKE CODE 1M2
TWIN LAKES
MEAN MONTHLY FLOWS AND DAILY FLOWS(CMS)
TRIBUTARY MONTH YEAf MEAN FLO*
1612D1
10
11
12
\
2
3
4
5
6
7
8
9
74
74
74
75
75
75
75
75
75
75
75
75
0.105
0.159
0.164
o.aio
0.283
0.765
1.47?
2.124
0.680
0.278
0.173
0.142
19
1?
If.
7
=;
FLOW DAY
0.099
0.210
0.136
0.453
FLOW DAY
FLOW
n.623
0.906
P.718
0.850
0.311
0.161
0.283 28
0.210
-------
APPENDIX C
PHYSICAL AND CHEMICAL DATA
-------
STOOET RETRIEVAL D»TE 76/08/25
NATL FUTROPHICATIOVJ SURVEY
EPA-LAS VEGAS
DATE
FDQM
TO
75/06/03
75/07/23
75/09/10
75/10/24
00010
TIME DEPTH WATER
OF TEMP
DAY FEET
12
12
12
13
13
13
14
14
14
10
10
10
15
15
15
15
15
15
30
30
30
30
30
30
0000
0005
0011
0000
0005
0010
0000
0005
0009
0000
0005
0010
CENT
15
15
15
24
23
23
14
14
14
10
10
10
.a
.7
.5
.2
.9
.7
.5
.3
.4
.4
.4
.0
161201
47 53 27.0 116 53 00.0 3
LOWER TWIN LAKES
16055 IDAHO
130292
11EPALES 2111208
0015 FEET DE^TH CLASS oo
00300
00
MG/L
9.0
9.0
9.0
8.6
8.8
7.6
9.0
9.0
9.0
9.0
8.8
9.2
00077
TRANS0
CECCHT
INCHES
126
144
144
156
00094
CNDUCTVY
FIELD
MJCROMhO
22
22
23
25
21
22
14
14
14
24
24
23
00400
PH
su
7.80
7.90
8.20
7.05
7.20
7.20
8.15
7.70
7.80
6.70
6.70
6.80
00410
T ALK
CAC03
MG/L
14
14
12
24
24
23
26
10
13
16
10K
10K
00610
NH3-N
TOTAL
MG/L
0.040
0.030
0.040
0.060
0.040
0.020
0.020K
0.020K
0.020K
0.030
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.400
0.400
0.400
0.800
O.*00
0.400
0.500
0.400
0.400
0.500
0.400
0.400
00630 00671
N02»s,N03 PHOS-DIS
N-TOTAL 09THO
MG/L MG/L P
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
n.012
0.011
0.007
0.012
0.009
0.009
0.004
0.002
0.002
0.018
0.006
0.003
DATE
FRO"
TO
75/06/03
75/07/23
75/09/10
75/10/24
TIME
OF
DAY
12 15
12 15
12 15
13 15
13 15
13 15
14 30
14 30
14 30
10 30
10 30
10 30
DEPTH
FEET
0000
0005
noil
0000
0005
0010
0000
0005
0009
0000
0005
0010
00665
PHOS-TOT
MG/L P
0.016
0.017
0.016
0.018
0.015
0.015
0.034
0.015
0.014
0.030
0.049
0.020
32217
CHLRPHYL
A
UG/L
1.7
2.9
3.7
2.8
00031
IWCDT LT
OFMNING
PERCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
5TOPET RETRIEVAL DATE 76/nR/25
NATL EUTROPHICATION SURVEY
EPA-LAS VEGAS
16120?
47 52 44.0 116 SI 59.0 3
LOWER TWIN LAKES
16055 IDAHO
130292
1 1EPALES
DATE
FPOM
TO
75/06/03
75/07/23
75/09/10
75/10/24
DATE
FROM
TO
75/06/03
75/07/23
75/09/10
75/10/24
TI"E OEPTH
OF
DAY FEET
12 35 0000
1? 35 0005
12 35 0015
12 35 0025
12 35 0048
13 35 0000
13 35 0005
13 35 0015
13 35 0030
13 35 0046
11 40 0000
11 40 0005
11 40 0020
11 40 0030
11 40 004C
09 50 0000
09 50 0005
09 50 0016
09 50 0040
09 50 0056
TIME DEPTH
OF
DAY FEET
12 35 0000
12 35 0005
12 35 0015
12 35 0025
12 35 0048
13 35 0000
13 35 0005
13 35 0015
13 35 0030
13 35 0046
11 40 0000
11 40 0005
11 40 00?0
11 40 0030
11 40 0045
09 50 0000
09 50 0005
09 50 0016
09 50 0040
00010
HATEP
TEMP
CENT
15.0
14.9
14.1
7.0
5.6
25.0
24.2
22.6
in. 6
8.0
14.7
14.4
12.3
6.4
3.6
11.3
11.2
11.?
10.9
B.I
00665
PHOS-TOT
MG/L P
0.012
0.016
0.013
0.012
0.012
0.013
0.013
0.015
O.OP4
0.02?
0.012
0.014
0.027
0.015
0.006
0.015
0.017
0.017
0,027
00300
DO
MG/L
8.
9.
9.
8.
8.
9.
a.
9.
5.
8.
8.
8.
a.
1.
1.
8.
8.
8.
7.
1.
32217
00077
TfcAMSP
SECCHI
INCHES
e 192
0
0
0
0
6
6
4
8
8
6 120
6
4
8
8
2 120
2
6
6
4
00031
00094
CNDUCTVY
FIELD
MICROMHO
22
23
22
19
20
20
19
17
12
17
14
10
8
8
9
25
24
24
24
32
005?
00400
PH
Sll
7.30
7.50
7.70
7.70
8.20
7.80
7.30
7.20
6.40
6.70
7.80
7.50
7.30
6.80
7.05
7.00
7.00
6.90
6.70
6.45
?1!
FEET DEPTH CLASS
00410
T ALK
CAC03
MG/L
14
16
17
15
18
24
22
24
16
18
17
16
15
16
15
10K
10K
10K
10K
10
00610
NH3-N
TOTAL
MG/L
0.030
0.040
0.030
0.030
0.030
0.030
0.020
0.030
0.090
0.040
0.020K
0.0?OK
0.020K
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
0.280
120?
on
00625
TOT KJEL
N
MG/L
0.200
0.300
0.300
0.300
0.300
0.500
0.200
0.200K
0.400
0.200K
0.200K
0.200K
0.200
0.200
0.200
0.200
0.200K.
0.200K
0.200K
0.400
006^0
N02S.N03
N-TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.030
0.020
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00671
PHOS-DIS
ORTHO
MG/L P
0.011
0.014
0.011
0.009
0.009
0.009
0.009
0.010
0.020
0.012
0.002
0.002K
0.005
0.006
0.002
0.003
0.004
0.004
0.010
0.149
CHLRPHYL INCDT LT
A
UG/L
1.
3.
2.
2.
RFMNING
PERCENT
i
7
5
5
K VALUE
KNOWN TO BE
LESS
THAN INDICATED
-------
STOSET RETRIEVAL OATE 76/08/25
NATL FUTROPHICATION SURVEY
FPA-LAS VEGAS
00010
DATE TIME DEPTH rfATER
FROM OF TEMP
TO DAY FEET CENT
75/06/03 13 00 0000 14.7
13 00 0005 13.7
75/07/23 13 55 0000 25.5
13 55 000* 25.3
75/09/10 14 15 0000 15.4
75/10/24 09 30 0000 9.3
09 30 000^ 9.3
00300
DO
MG/L
9.6
8.8
8.2
8.8
9.8
9.2
00077 00094
TRANSP CNDUC
^ECCHI FIELD
INCHES MICRO
72
96
161203
47 51 38.0 116 51 54.0 3
LOWER TWIN LAKES
16055 IDAHO
1303°!
11EDALES 2111202
OOOfl FEET DEPTH CLASS 00
14
VY
IHO
23
23
25
25
18
24
24
00400
PH
SU
8.00
8.00
7.40
7.40
7.90
7.10
7.10
00410
T ALK
CAC03
MG/L
17
21
13
14
25'
10
10K
00610
NH3-N
TOTAL
MG/L
0.030
0.040
0.050
0.030
0.020
0.020K
0.020K
00625
TOT KJEL
N
M(5/L
0.400
0.300
0.400
0.300
1.600
0.200K
0.?OOK
00630
NI02&N03
N-TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00671
PHOS-DIS
OPTHO
MG/L P
0.010
0.007
0.010
0.009
0.012
0.003
0.002
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/06/03 13 On 0000
13 00 0005
75/07/23 13 55 0000
13 55 0004
75/09/10 14 15 0000
75/10/24 09 30 0000
09 30 0005
0665
S-TOT
/L P
0.016
O.Olfl
0.016
0.016
0.422
0.013
0.015
32217
CHLRPHYL
A
UG/L
1.2
2.0
1 .4
00031
INCDT LT
PEMNING
PERCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 76/08/25
NATL FUTROPHIC4TION SURVEY
F.PA-LAS VEGAS
161301
47 53 15.0 116 55 10.0 3
UP°ER TWIN LAKES
16055 IDAHO
130292
11EPALES 2111202
0015 FEET DEPTH CLASS 00
DATE
FPOM
TO
75/06/03
75/07/23
75/09/10
75/10/24
DATE
FPOM
TO
75/06/03
75/07/23
75/09/10
75/10/24
TI'.'E DEPTH
OF
DAY FEET
11 30 0000
11 30 0005
11 30 0011
11 15 0000
11 15 0008
15 15 0000
15 15 0005
15 15 0009
12 05 0000
12 05 0005
TIME DEPTH
OF
DAY FEET
11 30 0000
11 30 0005
11 30 0011
11 15 0000
11 15 0008
15 15 0000
15 15 0005
15 15 0009
12 05 0000
12 05 0005
00010
4ATEP
TFMP
CFNT
U.7
14.6
12.4
21.5
20.4
16.2
15.9
14.3
9.2
fl. 8
00665
PHOS-TOT
MG/L P
0.016
0.019
O.Olfl
0.014
0.015
0.016
0.019
0.016
0.018
0.019
00300
00
MG/L
8.8
R.8
9.2
9.6
10.2
9.4
8.6
9.6
10.0
9.8
32217
CHLRPHYL
A
UG/L
2.5
1.9
19.4
2.5
00077
TRANSP
•JECCH!
INCHES
120
144
126
00031
INCDT LT
RFMNING
PERCENT
00094
CNDUCTVY
FIELD
MICROMHO
22
21
20
22
21
16
15
16
23
24
00400
PH
SL)
7.70
7.40
7.70
8.00
7.85
8.35
8.50
8.30
7.30
7.30
00410
T ALK
CAC03
MG/L
17
la
10K
20
19
14
12
16
10
18
00610
NH3-N
TOTAL
MG/L
0.100
0.040
0.040
0.060
0.020
0.030
0.0?OK
0.020K
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.400
0.400
0.300
0.600
0.400
0.400
0.400
0.400
0.300
0.200K
00630
N02S.N03
N-TOTAL
MG/L
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00671
PHOS-DIS
ORTHO
MG/L P
0.013
0.017
0.014
o.oii
0.009
0.003
0.002
0.002K
0.002K
0.005
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE
NATL EUTROPHICATION SURVEY
EPA-LAS VEGAS
DATE
FROM
TO
75/06/03
75/07/23
75/09/10
75/10/24
00010
TIME DEPTH 4ATER
OF TEMP
DAY FEET
11
11
11
11
11
11
14
14
14
11
11
11
55
55
55
30
30
30
45
45
45
45
45
45
0000
0005
OOl^
0000
000?
0013
0000
0005
0012
0000
0005
0010
CENT
15
15
9
22
22
19
15
15
15
10
10
9
.2
.2
.8
.2
.0
.3
.5
.1
.1
.1
.0
.9
161303
47 53 28.0 116 54 02.0 3
UPPER TWIN LAKES
16055 IDAHO
130392
11EPALES 2111202
0019 FEET DEPTH CLASS 00
00300
DO
MG/L
10.0
9.0
8.8
6.8
9.2
9.8
9.4
9.6
9.6
9.4
9.6
9.4
00077
TKANSP
SECCHI
INCHES
126
180
96
124
00094
CNDUCTVY
FIELD
MICROMHO
20
22
18
21
14
19
14
19
16
20
21
20
00400
PH
SU
8.00
7.90
7.70
7.60
7.80
8.70
7.60
8.20
8.30
6.90
7.00
7.00
00410
T ALK
CAC03
MG/L
10K
17
15
19
21
22
13
13
11
10K
10K
10K
00610
NH3-N
TOTAL
MG/L
0.040
0.050
0.030
0.040
0.040
0.040
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
00625
TOT KJEL
N
MG/L
0.600
0.400
0.300
0.600
0.400
0.300
0.400
0.400
0.600
0.400
0.300
0.300
006^0 00671
N02&N03 PHOS-DIS
N-TOTAL ORTHO
MG/L MG/L P
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.020K
0.014
0.007
0.012
0.004
0.009
0.014
0.002K
0.003
0.002
0.003
0.002
0.002
DATE TIME DEPTH
FROM OF
TO DAY FEET
75/06/03 11 55 0000
11 55 0005
11 55 0015
75/07/23 11 30 0000
11 30 0005
11 30 0013
75/09/10 14 45 0000
14 45 0005
14 45 0012
75/10/24 11 45 0000
11 45 0005
11 45 0010
0
s
/
0
0
0
0
n
0
0
n
0
n
0
0
665
-TOT
L P
.018
.017
.016
.015
.014
.021
.024
.022
.069
.014
.015
.018
32217
CHLRPHYL
A
UG/L
2.4
3.4
2.8
00031
INCDT LT
RFMNING
PERCENT
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
APPENDIX D
TRIBUTARY AND WASTEWATER
TREATMENT PLANT DATA
-------
STORE! RETRIEVAL DATE 76/08/35
NATL EUTROPHICATION SURVEY
EPA- LAS VEGAS
DATE TIME DEPTH NO?liN03
FROM OF
TO OAY FEET
74/10/19
74/11/18
74/12/16
75/01/18
75/02/16
75/03/16
75/04/13
75/05/16
75/06/07
75/07/05
75/07/08
75/07/28
75/08/08
75/09/10
13 50
10 45
10 30
13 15
14 05
10 20
11 30
14 30
11 45
10 30
11 05
11 00
09 00
11 40
1612A1
47 51 25.0 116 51 58.0 4
RATHDRUM CREEK
16 7.5 HAYDEN
0/TWIN LAKES 13030630
'S.N03
rnTAL
4G/L
0.024
0.024
0.040
0.032
0.040
0.035
0.070
0.010
0.010
0.005
0.010
0.005
0.025
0.010
00625
TOT KJEL
N
MG/L
0.200
0.100K
0.200
0.200
0.800
0.200
0.150
0.300
0.250
0.400
0.900
0.400
0.250
0.900
00610
NH3-N
TOTAL
MG/L
0.055
0.061
0.015
0.025
0.044
0.015
0.010
0.030
0.020
0.015
0.015
0.010
0.040
0.020
00671
PHOS-DIS
ORTHO
MG/L P
0.005K
0.005K
0.005
0.005K
0.008
0.005K
0.005K
0.005K
0.005K
0.005
0.005K
0.005K
0.010
0.005K
00665
PHOS-TOT
MG/L P
0.010
0.010K
0.010
0.010K
0.010K
0.010K
0.010K
0.010K
0.010
0.010K
0.010
0.030
0.040
0.010K
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STO«ET RETRIEVAL DATE 76/08/25
NATL FUTROPHICATION SURVEY
EPA- LAS VEGAS
DATE TIME DEPTH N02f,N03
FROM OF
TO DAY FEET
74/10/19
74/11/18
74/12/18
75/03/16
75/04/13
75/05/16
75/06/07
75/07/05
75/07/08
75/07/28
75/08/08
75/09/10
11
10
10
11
14
12
10
11
11
09
11
00
45
15
40
45
05
50
20
20
15
55
1612B1
47 51 27.0 116 51 59.0 4
UNNAMED STREAM
16 7.5 HAYDEN
T/TtolN LAKES
130301
GRVL RD OWDG ?.4 MI SW OF T*IN LKS STATN
11EPALES 2111304.
0000 FEET DEPTH CLASS 00
10630
'f,N03
OTAL
IG/L
0.016
0.128
0.336
0.375
0.575
0.210
0.070
0.065
0.105
0.110
0.080
0.065
00625
TOT KJEL
N
MG/L
0.9t)0
0.700
0.300
0.200
0.600
0.500
0.250
0.15T)
0.200
0.300
0.400
0.200
00610
NH3-N
TOTAL
HG/L
0.030
0.030
0.015
0.025
0.035
0.035
0.055
0.005
0.030
0.015
0.020
0.015
00671
PHOS-niS
ORTHO
HG/L P
0.005
0.025
0.010
0.005K
0.005K
0.005
0.020
0.005K
0.005
0.015
0.010
0.005
00665
OHOS-TOT
HG/L P
0.010
0.010
0.040
0.020
0.080
0.060
0.020
0.040
0.040
0.060
0.030
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 76/08/25
NATL EUTROPHICATION SURVEY
EPA- LAS VEGAS
DATE TIME DEPTH N02^N03
FROM OF
TO DAY FEET
74/10/19
74/11/18
74/12/16
75/04/13
75/05/16
75/06/07
75/07/05
75/07/08
75/07/28
75/08/08
75/09/10
14
11
11
12
15
13
11
13
12
12
55
40
30
20
30
15
50
00
10
30
1612C1
47 52 48.0 116 56 43.0 4
SHOVE CREEK
16 7.5 SPIRIT LK W
T/TWIN LAKES 130293
GRVL RD BRDG 4.2 MI WSW OF SLVR SNDS RCH
11EPALES 2111204
oooo FEET DEPTH CLASS oo
0630
S.N03
OTAL
G/L
0.016
0.032
0.016
0.025
0.030
0.010
0.005
0.010
0.015
0.010
0.015
00625
TOT KJEL
N
MG/L
0.300
0.200
0.200
0.250
1.450
0.700
0.100
0.050K
0.550
0.075
3.000
00610
NH3-N
TOTAL
MG/L
0.025
0.025
0.025
0.020
0.065
0.020
0.005K
0.005
0.010
0.010
0.040
00671
PHOS-DIS
ORTHO
MG/L P
0.015
0.020
0.015
0.015
0.010
0.010
0.015
0.015
0.020
0.020
0.015
00665
PHOS-TOT
MG/L P
0.025
0.040
0.020
0.015
0.010
0.010
0.020
0.020
0.030
0.045
0.020
K VALUE KNOWN TO BE LESS
THAN INDICATED
-------
STORET RETRIEVAL DATE 76/08/25
NATL EUTROPHICATION SURVEY
EPA- LAS VEGAS
DATE TIME DEPTH N02S.N03
FROM OF
TO OAY FEET
74/10/19
74/11/18
74/12/16
75/01/18
75/02/16
75/03/16
75/04/13
75/05/16
75/06/07
75/07/OS
75/07/08
75/07/28
75/08/08
75/09/10
14 40
11 30
11 04
14 00
14 30
11 00
12 10
15 15
13 00
11 30
12 50
11 55
09 45
12 50
1612D1
«7 53 09.0 116 57 06.0 4
FISH CREEK
16 7.5 SPIRIT LK W
T/TWIN LAKES 130393
GRVL RD BRDG 3.8 MI W OF SILVER SNDS RCH
11EPALES 2111204
0000 FEET DEPTH CLASS 00
0630
S.N03
OTAL
G/L
0.016
0.048
0.040
0.080
0.056
0.055
0.080
0.035
0.0.20
0.010
0.020
0.020
0.010
0.020
00625
TOT KJEL
N
MG/L
0.100
0.400
0.400
0.200
0.800
0.150
0.100
0.800
0.350
1.350
0.350
0.150
0.150
2.000
00610
MH3-N
TOTAL
MG/L
0.010
0.025
0.025
0.015
0.024
0.010
0.015
0.055
0.010
0.027
0.015
0.010
0.020
0.030
00671
PHOS-DIS
ORTHO
MG/L P
0.015
0.020
0.015
0.015
0.016
0.010
0.010
0.025
0.010
0.015
6.015
0.015
0.020
0.015
00665
PHOS-TOT
MG/L P
0.025
0.050
0.020
0.040
0.016
0.020
0.030
0.040
0.030
0.030
0.035
0.020
0.050
0.020
-------
APPENDIX E
PARAMETRIC RANKINGS OF LAKES
SAMPLED BY NES IN 1975
STATE OF IDAHO
Mean or median values for six of the key parameters evaluated
in establishing the trophic conditions of Idaho lakes sampled are
presented to allow direct comparison of the ranking, by parameter,
of each lake relative to the others. Median total phosphorus, median
inorganic nitrogen and median dissolved orthophosphorus levels are
expressed in mg/1. Chlorophyll a^ values are expressed in yg/1.
To maintain consistent rank order with the preceding parameters,
the mean Secchi disc depth, in inches, is subtracted from 500.
Similarly, minimum dissolved oxygen values are subtracted from 15
to create table entries.
-------
LAKE DATA TO BE USED IN RANKINGS
LAKE
CODE LAKE NAME
1601 AMERICAN FALLS RESERVOIR
1603 CASCADE LAKE
1603 LAKE COEUR D'ALENE
1604 OWORSHAK RESERVOIR
1605 MAUSER
1606 HAYDEN LAKE
1607 ISLAND PARK RESERVOIR
1603 LAKE LOWELL
1609 MAGIC RESERVOIR
1610 PALISADES RESERVOIR
1611 LOWER PAVETTE
1612 LOWER TWIN LAKES
1613 UPPER TWIN LAKES
MEDIAN
TOTAL P
0*105
0.032
0.017
0.010
0.023
0.010
0.034
0.070
0.062
0.024
0.013
0.016
0.017
MEDIAN
INORG N
0.030
0.060
0.040
0.080
0.075
0.040
0.050
0.070
0.130
0.080
0.060
0.050
0.045
500-
MEAN SEC
463.800
415.067
380.348
401.866
366.286
243.500
391.778
477.111
400.750
345.428
234.000
370.000
369.143
MEAN
CHLORA
15.379
8.031
10.391
2.420
11.112
2.787
9.322
25.389
7.322
2.067
4.600
2.318
4.986
15-
MIN 00
14.700
14.800
12.200
7.400
14.800 *
11.800
12.800
14.600
14.700
12.800
9.600
13.600
8.200
MEDU
OISS ORTj
0.035
0.009
0.005
0.009
0.013
0.003
0.012
0.015
0.020
0.007
0.007
0.009
0.004
-------
PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES)
LAKE
CODE LAKE NAME
1601 AMERICAN FALLS RESERVOIR
1602 CASCADE LAKE
1603 LAKE COEUR D'ALENE
1604 OWORSHAK RESERVOIR
1605 MAUSER
16O6 NAYDEN LAKE
1607 ISLAND PARK RESERVOIR
1608 LAKE LOWELL
1609 MAGIC RESERVOIR
1610 PALISADES RESERVOIR
1611 LOWER PAYETTE
1612 LOWER TWIN LAKES
1613 UPPER TWIN LAKES
MEDIAN
TOTAL P
0 <
33 <
67 (
96 1
42 <
96 1
25 1
8 1
17 1
50 1
83 1
75 1
58 <
[ 0)
I 4)
: 8)
: ID
; 5)
: in
! 3)
[ 1)
t 2)
I 6)
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