U.S. ENVIRONMENTAL PROTECTION AGENCY NATIONAL EUTROPHICATION SURVEY WORKING PAPER SERIES REPORT ON BLACK HAWK LAKE SACCOUNIY IOWA EPA REGION VII WORKING PAPER No, 496 CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY - CORVALLIS, OREGON and ENVIRONMENTAL MONITORING & SUPPORT LABORATORY - LAS VEGAS, NEVADA 699-440 ------- c REPORT ON BLACK HAWK LAKE SAC COUNTY IOWA EPA REGION VII WORKING PAPER No, 496 WITH THE COOPERATION OF THE IOWA DEPARTMENT OF ENVIRONMENTAL QUALITY AND THE IOWA NATIONAL GUARD AUGUST, 1976 ------- CONTENTS Page Foreword ii List of Iowa Study Lakes iv Lake and Drainage Area Map v v Sections I. Conclusions 1 II. Lake and Drainage Basin Characteristics 3 III. Lake Water Quality Summary 4 IV. Nutrient Loadings 8 V. Literature Reviewed 12 VI. Appendices 13 ------- ii FOREWORD The National Eutrophication Survey was initiated in 1972 in response to an Administration commitment to investigate the nation- wide threat of accelerated eutrophication to freshwater lakes and reservoirs. OBJECTIVES The Survey was designed to develop, in conjunction with state environmental agencies, information on nutrient sources, concentrations, 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 non-point source pollution abatement in lake watersheds. ANALYTIC APPROACH The mathematical and statistical procedures selected for the Survey's eutrophication 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 water- shed 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 planning [§303(e)], water quality criteria/standards review [§303(c)], clean lakes [§314(a,b)J, and water quality monitoring [§106 and §305(b)] activities mandated by the Federal Water Pollution Control Act Amendments of 1972. ------- m Beyond the single lake analysis, broader based correlations between nutrient concentrations (and loading) and trophic condi- tion are being made to advance the rationale and data base for refinement 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 EPA and to augment plans implementation by the states. ACKNOWLEDGMENT The staff of the National Eutrophication Survey (Office of Research & Development, U. S. Environmental Protection Agency) expresses sincere appreciation to the Iowa Department of Environ- mental Quality for professional involvement, to the Iowa National Guard for conducting the tributary sampling phase of the Survey, and to those wastewater treatment plant operators who voluntarily provided effluent samples and flow data. The staff of the Water Quality Division of the Department of Environmental Quality provided invaluable lake documentation and counsel during the Survey, reviewed the preliminary reports, and provided critiques most useful in the preparation of this Working Paper series. Major General Joseph G. May, the Adjutant General of Iowa, and Project Officer Colonel Cleadeth P. Woods, who directed the volunteer efforts of the Iowa National Guardsmen, are also grate- fully acknowledged for their assistance to the Survey. ------- IV LAKE NAME Ahquabi Big Creek Reservoir Black Hawk Clear Darl ing Lost Island MacBride Prairie Rose Rathbun Reservoir Red Rock Reservoir Rock Creek Silver Spirit Viking West Okoboji NATIONAL EUTROPHICATION SURVEY STUDY LAKES STATE OF IOWA COUNTY Warren Polk Sac Cerro Gordo Washington Clay, Palo Alto Johnson Shelby Appanoose, Wayne Marion Jasper Worth Dickinson Montgomery Dickinson ------- Iowa Map Location BLACK HAWK LAKE <8> Tributary Sampling Site X Lake Sampling Site •Z3 Drainage Area Boundary 1 Scale 2 4215— 3 Mi. 9505 9500 42*10- ------- BLACK HAWK LAKE STORE! NO. 1903 I. CONCLUSIONS A. Trophic Condition: Survey data indicate that Black Hawk Lake is eutrophic. This lake ranked fourteenth in overall trophic quality when the 15 Iowa lakes and reservoirs sampled in 1974 were com- pared using a combination of six parameters*. Thirteen of the water bodies had less median total phosphorus, 11 had less median dissolved phosphorus, four had less and one had the same median inorganic nitrogen, 13 had less mean chlorophyll a_, and all of the other water bodies had greater Secchi disc transparency. Survey limnologists did not observe surface concentrations of algae, but the numbers of phytoplankton in July and Sep- tember indicate blooms at those times (see page 6). B. Rate-Limiting Nutrient: The algal assay results indicate that Black Hawk Lake was phosphorus limited at the time the assay sample was collected (04/19/74). The lake data indicate phosphorus limitation in April but nitrogen limitation in September. C. Nutrient Controllability: 1. Point sources—During the sampling year, the phos- * See Appendix A. ------- 2 phorus contributions of domestic point sources amounted to 1.2% of the total phosphorus load. All of this load is attributed to lakeshore septic tanks, but a shoreline survey would be necessary to determine the actual significance of those sources. The present loading of 0.55 g/m2/year is well over that proposed by Vollenweider (Vollenweider and Dillon, 1974) as a eutrophic loading (see page 11). Because this lake is phos- phorus limited at least part of the time, the incoming phos- phorus load should be reduced to the greatest practicable extent. 2. Non-point sources--The phosphorus contribution of non- point sources accounted for 98.8% of the total phosphorus load during the sampling year. The Unnamed Stream B-l contributed 79.6%, and ungaged tributaries were estimated to have contrib- uted 16.0% of the, load. ------- II. LAKE AND DRAINAGE BASIN CHARACTER1STICSf A. Lake Morphemetry : 1. Surface area: 3.72 kilometers2. 2. Mean depth: 1.7 meters. 3. Maximum depth: 3.7 meters. 4. Volume: 6.324 x 106 m3. 5. Mean hydraulic retention time: 271 days. B. Tributary and Outlet: (See Appendix C for flow data) 1. Tributaries - Drainage Mean flow Name area (km2)* (m3/sec)* Unnamed Stream B-l 47.1 0.21 Minor tributaries & immediate drainage - 9.5 0.06 Totals 56.6 0.27 2. Outlet - Unnamed Stream A-l 60.3** 0.27 C. Precipitation***: 1. Year of sampling: 83.7 centimeters. 2. Mean annual: 72.6 centimeters. t Table of metric conversions—Appendix B. tt Harrison, 1975. * For limits of accuracy, see Working Paper No. 175, "...Survey Methods, 1973-1976". ** Includes area of lake. *** See Working Paper No. 175. ------- 4 III. LAKE WATER QUALITY SUMMARY Black Hawk Lake was sampled three times during the open-water season of 1974 by means of a pontoon-equipped Huey helicopter. Each time, samples for physical and chemical parameters were collected from a number of depths at two stations on the lake (see map, page v). During each visit, a single depth-integrated (near bottom to surface) sample was composited from the stations for phytoplankton identification and enumeration; and during the first visit, a single 18.9-liter depth-integrated sample was composited for algal assays. Also each time, a depth-integrated sample was collected from each of the stations for chlorophyll ^analysis. The maximum depth sampled at each of the stations was 0.6 meters. The sampling results are presented in full in Appendix D and are summarized in the following table (the July nutrient samples were not preserved properly and were not analyzed). ------- PARAMETER TEMP (0 DISS OXY (MG/L) CNDCTVY (MCftOMO) PH (STAND UNITS) TOT ALK (MG/L) TOT P (MG/L) ORTHO P (MG/L) N02»N03 (MG/L) AMMONIA (MG/L) KJEL N (MG/L) 1NORG N (MG/L) TOTAL N (MG/L) CHLRPYL A (UG/L) SECCHI (METERS) A. SUMMARY OF PHYSICAL AND 1ST SAMPLING ( 4/19/74) 2 SITES RANGE MEAN MEDIAN 12.4 - 12.7 12.5 12.5 «««**• -«•«•»*«*•«*«••••*•*••* 186. - 187. 187. 187. 8.6 - 8.6 8.6 8.6 168. - 177. 173. 173. 0.161 - 0.168 0.164 0.164 0.012 - 0.013 0.012 0.012 2.150 - 2.390 0.040 - 0.060 1.400 - 1.800 2.190 - 2.450 3.790 - 3.950 CHEMICAL CHARACTERISTICS FOR BLACK HAWK LAKE STORET CODE 1903 50.3 - 59.3 0.2 - 0.2 2.270 2.270 0.050 0.050 1.600 1.600 2.320 2.320 3.870 3.870 54.8 0.2 2ND SAMPLING ( 7/ 3/74) 2 SITES RANGE 24.5 - 25.2 8.0 456. - 467. 8.9 - 8.9 MEAN MEDIAN 24.9 24.9 462. 462. 8.9 8.9 »«**•*•***••• 54.8 0.2 «•*•*• -«**>***••**••••«****•» »«*••• _•**•*«•*•»•»****•*•••* «•««*» _****»«*»***«*•*••***•* •••*•• _*»***»*•«•*••*»»*»•*•« «»**** _•»«•*••**•••*•••*••»»« ««*•** -«***•*•>***«*«•*«»**•* 43.7 - 43.7 43.7 43.7 0.4 - 0.4 0.4 0.4 3RD SAMPLING ( 9/25/74) 2 SITES RANGE MEAN MEDIAN 14.6 - 15.2 14.9 14.9 8.6 - 9.0 8.8 8.8 321. - 323. 322. 322. 8.1 - 8.2 8.2 8.2 145. - 148. 146. 145. 0.181 - 0.198 0.191 0.193 0.019 - 0.024 0.022 0.022 0.040 - 0.070 0.955 0.055 0.060 - 0.070 0.067 0.070 1.600 - 1.700 0.110 - 0.130 1.640 - 1.770 45.7 - 49.7 0.3 - 0.3 1.625 1.600 0.122 0.125 1.680 47.7 0.3 1.655 47.7 0.3 ------- B. Biological characteristics: 1. Phytoplankton - Sampling Date 04/19/74 07/03/74 09/25/74 2. Chlorophyll a_ - Sampling Date 04/19/74 07/03/74 09/25/74 Dominant Genera 1. Nitzschia sp. 2. StejahanocTiscus sp. 3. Flage!1ates 4. Cryptomonas sp. 5. Ankistrodesmus sp. Other genera Total 1. Aphanizomenon sp. 2. Sphaerocystis sp. 3. Oocystis sp. 4. Crucigem'a sp. 5. Stephanodiscus sp. Other genera Total 1. Merismopedia sp. 2. Oscillatoria sp. 3. Flagellates 4. Aphanizomenon sp. 5. Stephanodiscus sp. Other genera Total Station Number 1 2 1 2 1 2 Algal Units per ml 20,657 16,611 9,796 3,194 2,875 5.964 59,097 9,323 6,447 5,612 1,160 835 1.855 25,232 28,092 3,904 3,140 2,885 2,631 13.665 54,317 Chlorophyll a (ug/D 50.3 59.3 43.7 45.7 49.7 ------- 7 C. Limiting Nutrient Study: 1. Autoclaved, filtered, and nutrient spiked - Ortho P Inorganic N Maximum yield Spike (mg/1) Cone, (mg/1) Cone, (mg/1) (mg/l-dry wt.) Control 0.040 2.380 15.6 0.050 P 0.090 2.380 29.4 0.050 P + 1.0 N 0.090 3.380 32.0 1.0 N 0.040 3.380 15.2 2. Discussion - The control yield of the assay alga, Selenastrum capri- cornutum, indicates that the potential primary productivity of Black Hawk Lake was high at the time the sample was col- lected (04/19/74). The addition of only phosphorus pro- duced a significant increase in yield, but no such increase occurred with the addition of only nitrogen. Therefore, phosphorus limitation is indicated. The lake data substantiate phosphorus limitation during April (the mean inorganic nitrogen/orthophosphorus ratio was 193/1). However, nitrogen limitation is indicated in September (the mean N/P ratio was 6/1). ------- 8 IV. NUTRIENT LOADINGS (See Appendix E for data) For the determination of nutrient loadings, the Iowa 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 months of April, May, and June when two samples were collected. Sampling was begun in August, 1974, and was completed in July, 1975. Through an interagency agreement, stream flow estimates for the year of sampling and a "normalized" or average year were provided by the Iowa District Office of the U.S. Geological Survey for the tributary sites nearest the lake. In this report, nutrient loads for sampled tributaries were determined by using a modification of a U.S. Geological Survey computer program for calculating stream loadings*. Nutrient loads for unsampled "minor tributaries and immediate drainage" ("II" of U.S.G.S.) were estimated using the nutrient loads at station B-l, in kg/km2/year, and multiplying by the II area in km2. No known point sources impacted Black Hawk Lake during the sampling year. * See Working Paper No. 175. ------- 9 A. Waste Sources: 1. Known municipal - None 2. Known industrial - None B. Annual Total Phosphorus Loading - Average Year: 1. Inputs - kg P/ % of Source yr total a. Tributaries (non-point load) - Unnamed Stream B-l 1,620 79.6 b. Minor tributaries & immediate drainage (non-point load) - 325 16.0 c. Known municipal STP's - None d. Septic tanks* - 25 1.2 e. Known industrial - None f. Direct precipitation** - 65_ 3.2 Total 2,035 100.0 2. Outputs - Lake outlet - Unnamed Stream A-l 1,635 3. Net annual P accumulation - 400 kg. * Estimate based on five parks, two camps, and 55 lakeshore dwellings (LeFevre, 1976); see Working Paper No. 175. ** See Working Paper No. 175. ------- 10 C. Annual Total Nitrogen Loading - Average Year: 1. Inputs - kg N/ % of Source y_r total a. Tributaries (non-point load) - Unnamed Stream B-l 62,890 78.1 b. Minor tributaries & immediate drainage (non-point load) - 12,680 15.8 c. Known municipal STP's - None d. Septic tanks* - 905 1.1 e. Known industrial - None f. Direct precipitation** - 4,015 5.0 Total 80,490 100.0 2. Outputs - Lake outlet - Unnamed Stream A-l 23,995 3. Net annual N accumulation - 56,495 kg. D. Non-point Nutrient Export by Subdrainage Area: Tributary kg P/km2/yr kg N/km2/yr Unnamed Stream B-l 34 1,335 * Estimate based on five parks, two camps, and 55 lakeshore dwellings (LeFevre, 1976); see Working Paper No. 175. ** See Working Paper No. 175. ------- 11 E. Yearly Loads: In the following table, the existing phosphorus loadings are compared to those proposed by Vollenweider (Vollenweider and Dillon, 1974). Essentially, his "dangerous" loading is one at which the receiving water would become eutrophic or remain eutrophic; his "permissible" loading is that which would result in the receiving water remaining oligotrophic or becoming oligotrophic if morphometry permitted. A meso- trophic loading would be considered one between "dangerous" and "permissible". Note that Vollenweider's model may not be applicable to water bodies with short hydraulic retention times. Total Phosphorus Total Nitrogen Total Accumulated' Total Accumulated grams/m2/yr 0.55 0.11 21.6 15.2 Vollenweider phosphorus loadings (g/m2/yr) based on mean depth and mean hydraulic retention time of Black Hawk Lake: "Dangerous" (eutrophic loading) 0.30 "Permissible" (oligotrophic loading) 0.15 ------- 12 V. LITERATURE REVIEWED Harrison, Harry M., 1975. Personal communication (lake morphometry), IA Cons. Comm., Des Moines. Le Fevre, John, 1976. Personal communication (shoreline dwellings at Black Hawk Lake). IA Dept. of Env. Qual., Spencer. Vollenweider, R. A., and P. J. Dillon, 1974. The application of the phosphorus loading concept to eutrophication research. Natl. Res. Council of Canada Pub!. No. 13690, Canada Centre for Inland Waters, Burlington, Ontario. ------- VI. APPENDICES APPENDIX A LAKE RANKINGS ------- LAKE DATA TO BE USED IN RANMNGS LAKE CODE LAKE NAME 1901 LAKE ACQUAdI 1902 BIG CREEK RESESVOIR 1903 BLACK HAWK LAKE 1904 CLEAR LAKE 1905 LAKE DARLING 1906 LOST ISLAND LAKE 1907 LAKE MACBRIDE 1908 PRAIRIE ROSE LAKE 1909 RATHBUN RESERVOIR 1910 RED ROCK LAKE 1911 ROCK CREEK LAKE 1912 SILVER LAKE 1913 SPIRIT LAKE 1914 VIKING LAKE 1915 WEST LAKE OKOBOJI MEDIAN TOTAL ? 0.062 0.046 0.185 0.059 0.077 0.146 0.061 0.056 0.071 0.180 0.065 0.193 0.041 0.075 0.046 MEDIAN INO«G N 0.3J5 6.465 0.130 0.070 1.475 0.065 2.035 0.210 1.170 1.880 1.400 0.565 0.090 0.130 0.060 500- MEAN SEC 469.333 436.500 488.167 465.125 482.500 421.167 458.444 463.667 475.889 473.400 480.500 482.667 422.667 459.000 380.444 MEAN CMLOrtA 8.600 16.867 49.740 17.400 13.817 36.100 17.067 17.350 12.039 14.730 18.367 95.300 12.622 26.033 7.722 15- MIN 00 8.200 14.800 15.000 8.600 9.200 8.400 15.000 8.600 14.000 14.000 8.400 10.000 9.000 14.200 15.000 MEDIAN DISS OKTnO P 0.009 0.011 0.020 0.010 0.012 0.021 0.010 0.010 0.008 0.104 0.007 0.034 0.007 0.017 0.017 ------- PERCENT OF LAKES WITH HIGHER VALUES (NUMBER OF LAKES WITH HIGHER VALUES) LAKE CODE LAKE NAME 1901 LAKE ACOUABI 1902 BIG CREEK RESERVOIR 1903 BLACK HAWK LAKE 1904 CLEAR LAKE 1905 LAKE DARLING 1906 LOST ISLAND LAKE 1907 LAKE M4CBRIOE 1908 PRAIRIE ROSE LAKE 1909 RATHBUN RESERVOIR 1910 RED ROCK LAKE 1911 ROCK CREEK LAKE 1912 SILVER LAKE 1913 SPIRIT LAKE 1914 VIKING LAKE 1915 WEST LAKE OKOdOJI MEDIAN TOTAL P 57 89 7 71 29 21 64 79 43 1* 50 0 100 36 P9 ( 8) < 12) ( 1) ( 10) ( 4) ( 3) ( 9) < ID ( 6) ( 2> ( 7) ( 0) ( 14) ( 5) ( 12) MEDIAN INO*G N 50 ( 0 ( 68 ( 86 ( 21 ( 93 ( 7 ( 57 ( 36 ( 14 ( 29 ( 43 ( 79 ( 68 ( 100 ( 7) 0) 9) 12) 3) 13) 1) 8) 5) 2) 4) 6) 11) 9) 14) 500- MEAN SEC 43 ( 79 < 0 ( 50 ( 14 ( 93 ( 71 ( 57 ( 29 ( 36 ( 21 < 7 ( 86 ( 64 ( 100 ( 6) 11) 0) 7) 2) 13) 10) 8) 4) 5) 3) 1) 12) 9) 14) MEAN C*LORA 93 ( 57 ( 7 ( 36 ( 71 ( 14 ( 50 ( 43 < 86 ( 64 ( 29 ( 0 ( 79 ( 21 ( 100 ( 13) 8) 1) 5) 10) 2> 7) 6) 12) 9) 4) 0) 11) 3) 14) 15- MIN DO 100 ( 21 < 7 ( 75 ( 57 ( 89 ( 7 < 75 ( 39 ( 39 ( 89 ( 50 < 64 ( 29 ( 7 ( 14) 3) 0) 10) 8) 12) 0) 10) 5) 5) 12) 7) 9) 4) 0) MEDIAN DISS ORTHO P 79 ( 50 ( 21 ( 64 ( 43 ( 14 ( 64 ( 64 ( 86 ( 0 ( 96 ( 7 ( 96 ( 32 ( 32 I 11) 7) 3) 8) 6) 2) 8) 8) 12) 0) 13) 1) 13) 4) 4) INDEX NO 422 296 110 382 235 324 263 375 319 167 314 107 504 250 428 ------- LAKES RANKED BY INDEX NOS. RANK LAKE CODE LAKE NAME INDEX NO 1 1913 SPIRIT LAKE 504 2 1915 WEST LAKE OK080JI 428 3 1901 LAKE ACOUABI <»22 4 1904 CLEAR LAKE 382 5 1908 PRAIRIE ROSE LAKE 375 6 1906 LOST ISLAND LAKE 324 7 1909 RATHBUN RESERVOIR 319 8 1911 ROCK CREEK LAKE 314 9 1902 BIG CREEK RESERVOIR 296 10 1907 LAKE MACBRIDE 263 11 1914 VIKING LAKE 250 12 1905 LAKE DARLING 235 13 1910 RED ROCK LAKE 167 14 1903 BLACK HAWK LAKE 110 15 1912 SILVER LAKE 107 ------- APPENDIX B CONVERSION FACTORS ------- CONVERSION FACTORS Hectares x 2.471 = acres Kilometers x 0.6214 = miles Meters x 3.281 = feet -4 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/square kilometer x 5.711 = Ibs/square mile ------- APPENDIX C TRIBUTARY FLOW DATA ------- TRIBUTARY FLOW INFORMATION FOR IOWA LAKE CODE 1903 BLACKHAMK SUB-DRAINAGE TRIBUTARY AREAIS9 KH) 12/23/75 1903A1 190381 19032Z 60.3 13.2 OF LAKE (SO KH) 60. JAN O.Ob 0.04 0.01 FEB 0.16 0.12 0.03 MAR 0.57 0.45 0.13 .3 APR 0. 0. 0. 43 34 09 MAY 0.52 0.41 0.11 NORMALIZED FLOWS (CMS) JUN JUL AUG 0.45 0.35 0.10 0.21 0.16 0.05 0.36 0.28 0.08 SEP 0.19 0.15 0.04 OCT NOV 0.13 0.09 0.10 0.07 0.03 0.02 DEC MEAN 0.07 0.27 0.05 0.21 0.02 0.06 SUMMARY OTAL iUM OF DRAINAGE AREA OF LAKE * SUB-DRAINAGE AREAS ' 60.3 60.3 TOTAL FLOW TOTAL FLOW IN « OUT * 3.24 3.24 MEAN MONTHLY FLOWS AND DAILY FLOWS(CMS) TRIBUTARY MONTH YEAR MEAN FLOW DAY 1903A1 190381 1903ZZ 8 9 10 11 12 1 2 3 4 5 6 7 a 9 10 11 12 1 2 3 4 s 6 7 6 9 10 11 12 1 2 3 4 5 6 1 74 74 74 74 74 75 75 75 75 75 75 75 74 74 74 74 74 75 75 75 75 75 75 75 74 74 74 74 74 75 75 75 75 75 75 75 0.01 0.01 0.01 0.0 0.0 0.0 0.0 0.0 0.62 0.62 0.54 0.24 0.01 0.01 0.01 0.0 0.0 0.0 0.0 0.0 0.51 0.48 0.48 0.21 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.0 0.14 0.14 0.14 0.06 17 21 2 20 25 22 26 10 12 12 24 17 21 2 20 25 22 26 10 12 12 24 FLOW DAY 0.01 0.01 0.0 0.0 0.0 0.0 0.0 0.48 0.68 0.45 0.20 0.01 0.01 0.0 0.0 0.0 0.0 0.0 0.37 0.54 0.40 0.17 26 27 27 26 27 27 FLOW DAY FLOW 0.34 0.40 0.48 0.26 0.31 0.42 ------- APPENDIX D PHYSICAL and CHEMICAL DATA ------- STORET RETRIEVAL DATE 75/12/23 190301 42 18 00.0 095 00 45.0 BLACK HAWK LAKE 19161 IOWA DATE FROM TO 74/04/19 74/07/03 74/09/25 DATE FROM TO 74/04/19 74/09/25 TIME DEPTH OF DAY FEET 13 45 0000 15 00 0000 09 50 0000 09 50 0002 TIME DEPTH OF DAY FEET 13 45 0000 09 50 0000 09 50 0002 00010 WATER TEMP CENT 12.7 25.2 15.2 15.2 00665 PHOS-TOT MG/L P 0.161 0.181 0.197 00300 00 MG/L 9.0 8.6 32217 CHLRPHYL A UG/L 50.3 45.7 00077 TRANSP SECCHI INCHES 9 14 12 00031 INCDT LT REMNING PERCENT 1.0 00094 CNDUCTVY FIELD MICROMHO 186 467 323 323 11EPALES 3 00400 PH ,. SU 8.60 8.90 8.22 8.23 00410 T ALK CAC03 MG/L 177 145 145 2111202 0005 FEET DEPTH 00610 NH3-N TOTAL MG/L 0.060 0.070 0.070 00625 TOT KJEL N MG/L 1.400 1.600 1.600 00630 N02&N03 N-TOTAL HG/L 2.390 0.060 0.050 00671 PHOS-OIS ORTHO MG/L P 0.813 0.022 0.024 ------- STORE! RETRIEVAL DATE 75/12/33 190302 42 17 24.0 095 01 48.0 BLACK HAtfK LAKE 19161 I OH A DATE TIME DEPTH WATER FROM OF TEMP TO DAY FEET CENT 74/04/19 13 55 0000 12.4 74/07/03 14 50 0000 24.5 74/09/25 10 15 0000 14.6 10 15 0002 14.6 00665 DATE TIME DEPTH PHOS-TOT FROM OF TO DAY FEET MG/L P 74/04/19 13 55 0000 0.168 74/07/03 14 50 0000 74/09/25 10 15 0000 0.189 10 15 0002 0.198 11EPALES 00300 DO MG/L ' 8.0 9.0 8.6 32217 CHLRPHYL A UG/L 59.3 43.7 49.7 06077 ®@094 TRANSP CNDUCTVY SECCHI FIELD INCHES MICROMHO 9 187 15 456 12 321 321 00031 INCDT LT REMNING PERCENT 17.0 3 00600 PH SU 8.60 8.90 8.14 8.14 00410 T ALK CAC03 MG/L 168 145 148 2111202 0006 00610 NH3-N TOTAL MG/L 0.040 0.060 0.070 FEET DEPTH 00625 00630 TOT KJEL N02&N03 N N-TOTAL MG/L MG/L 1.800 2.150 1.700 0.070 1.600 0.040 00671 PHOS-OSS ORTHQ MG/L P 0.012 6.019 0.022 1.0 ------- APPENDIX E TRIBUTARY DATA ------- STORET RETRIEVAL DATE 76/01/27 1903A1 42 17 30.0 095 00 40.0 UNNAMED STREAM 19015 SAC CO IA rIMY MP 0/BLACKHAWK LAKE BRDG ON RO 2 MI ESE OF LAKE VIEW 11EPALES 2111204 4 0000 FEET DEPTH DATE FROM TO 74/08/17 74/09/21 75/04/10 75/04/26 75/05/12 75/05/27 75/06/12 75/06/27 75/07/24 TIME DEPTH OF DAY FEET 15 20 13 30 16 10 19 00 20 00 19 35 20 01 19 50 16 50 00630 N02&N03 N-TOTAL MG/L 0.136 0.020 0.750 0.010 0.125 0.095 0.540 0.390 0.010 00625 TOT KJEL N MG/L 1.900 2.100 2.700 2.800 4.000 1.680 3.700 2.100 1.350 00610 NH3-N TOTAL MG/L 0.120 0.020 0.045 0.030 0.045 0.220 0.875 0.540 0.030 00671 PHOS-DIS ORTHO MG/L P 0.015 0.020 0.035 0.040 0.020 0.020 0.065 0.095 0.290 00665 PHOS-TOT MG/L P 0.155 0.180 0.260 0.200 0.180 0.090 0.200 0.140 0.380 ------- STORET RETRIEVAL DATE 76/01/27 1903B1 42 17 00.0 095 03 00.0 UNNAMED STREAM 19 SAC CO IA HWY MP T/BLACKHAMK LAKE BRDG ON RD 1 MI S OF LAKE VIEW 11EPALES 2111204 4 0000 FEET DEPTH DATE FROM TO 74/08/17 74/09/21 74/10/20 74/11/03 75/04/10 75/04/26 75/05/12 75/05/27 75/06/12 75/06/27 75/07/24 TIME DEPTH OF DAY FEET 15 50 14 00 10 18 14 00 15 53 19 10 20 10 19 45 20 10 20 17 17 00 00630 N02&N03 N-TOTAL MG/L 1.200 0.020 0.024 0.016 9.600 8.700 10.000 10.500 10.500 9.700 1.150 00625 TOT KJEL N MG/L 1.600 2.800 1.600 2.000 1.500 1.180 1.250 0.900 1.700 1.200 2.400 00610 NH3-N TOTAL MG/L 0.270 0.060 0.185 0.150 0.165 0.165 0.025 0.070 0.100 0.105 0.230 00671 PHOS-DIS ORTHO MG/L P 0.280 0.090 0.040 0.045 0.150 0.180 0.005 0.065 0.095 0.090 0.190 00665 PHOS-TOT MG/L P 0.470 0.420 0.260 0.230 0.290 0.260 0.120 0.130 0.220 0.190 0.500 ------- |