U.S. ENVIRONMENTAL PROTECTION AGENCY NATIONAL EUTROPHICATION SURVEY WORKING PAPER SERIES REPORT ON GULL LAKE (SOUTH BASIN) CASS AND CROW WING COUNTIES MINNESOTA EPA REGION V WORKING PAPER No, 102 PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY An Associate Laboratory of the NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON and NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA ifOPO— C97.O3Z ------- REPORT ON GULL LAIC (SOUTH BASIN) CASS AND CR3W WING COUNTIES MINNESOTA EPA REGION V WORKING PAPER No, 102 WITH THE COOPERATION OF THE MINNESOTA POLLUTION CONTROL AGENCY AND THE MINNESOTA NATIONAL GUARD JULY, 1975 ------- 1 CONTENTS Page Foreword ii List of Minnesota Study Lakes tv, v Lake and Drainage Area Map vi Sections I. Conclusions 1 II. Lake and Drainage Basin Characteristics 3 III. Lake Water Quality Summary 4 IV. Nutrient Loadings 9 V. Literature Reviewed 13 VI. Appendices 14 ------- 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 fresh water 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 [ 3O3(e)], water quality criteria/standards review { 3O3(c)], clean lakes [ 3l4(a,b)], and water quality monitoring [ 5106 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 condi- tion are being made to advance the rationale and data base for refinement of nutrient water quality criteria for the Nation’s fresh water 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 Minnesota Pollution Control Agency for professional involvement and to the Minnesota National Guard for conducting the tributary sampling phase of the Survey. Grant J. Merritt, Director of the Minnesota Pollution Control Agency, John F. McGuire, Chief, and Joel G. Schilling, Biologist, of the Section of Surface and Groundwater, Division of Water Quality, provided invaluable lake documentation and counsel during the course of the Survey; and the staff of the Section of Municipal Works, Divi- sion of Water Quality, were most helpful in identifying point sources and soliciting municipal participation in the Survey. Major General Chester J. Moeglein, the Adjutant General of Minnesota, and Project Officer Major Adrian Beltrand, who directed the volunteer efforts of the Minnesota National Guardsmen, are also gratefully acknowledged for their assistance to the Survey. ------- iv NATIONAL EUTROPHICATION SURVEY STUDY LAKES STATE OF MINNESOTA LAKE NAME COUNTY Albert Lea Freeborn Andrusia Beltrami Badger Polk Bartlett Koochiching Bear Freeborn Bemidji Beltrami Big Stearns Big Stone Big Stone, MN; Roberts, Grant, SD Birch Cass Blackduck Beltrami Blackhoof Crow Wing Budd Martin Buffalo Wright Calhoun Hennepin Carlos Douglas Carrigan Wright Cass Beltrami, Cass Clearwater Wright, Stearns Cokato Wright Cranberry Crow Wing Darling Douglas Elbow St. Louis Embarass St. Louis Fall Lake Forest Washington Green Kandiyohi Gull Cass Heron Jackson Leech Cass Le Hornme Dieu Douglas Lily Blue Earth Little Grant Lost St. Louis ------- V LAKE NAME COUNTY Madison Blue Earth Malmedal Pope Mashkenode St. Louis McQuade St. Louis Minnetonka Hennepin Minnewaska Pope Mud Itasca Nest Kandiyohi Pelican St. Louis Pepin Goodhue, Wabasha, MN; Pierce, Pepin, WI Rabbit Crow Wing Sakatah Le Sueur Shagawa St. Louis Silver McLeod Six Mile St. Louis Spring Washington, Dakota St. Croix Washington, MN; St. Croix, Pierce, WI St. Louis Bay St. Louis, MN; Douglas, WI Superior Bay St. Louis, MN; Douglas, WI Swan Itasca Trace Todd Trout Itasca Wagonga Kandiyohi Walimark Chisago White Bear Washington Winona Douglas Wolf Beltranii, Hubbard Woodcock Kandiyohi Zumbro Olmstead, Wabasha ------- Lake Shore S Map Location GULL LAKE Tributary Sampi I ng Lake Sampling Site I- ------- GULL LAKE (SOUTH BASIN) STORET NO. 2737 I. CONCLUSIONS A. Trophic Condition: Survey data indicate that the south basin of Gull Lake is eutrophic. Of the 60 Minnesota lakes on which sampling was completed, 18 had less and one the same mean total phos- phorus, 27 had less and one the same mean dissolved phosphorus, 23 had less mean inorganic nitrogen, 27 had less and one the same mean chlorophyll a, but only eight had greater mean Secchi disc transparency. Hypolimnetic dissolved oxygen was markedly depressed at all three sampling stations in July and was depleted or nearly so below 30 feet in depth in September, 1972. While phytoplankton numbers were not exceptionally high, blue- green algae were prominent in all samples. B. Rate-Limiting Nutrient: The algal assay results indicate Gull Lake was nitrogen limited at the time the sample was taken (10/24/72). The lake data also indicate nitrogen limitation at that time but indicate phosphorus limitation in July and September. C. Nutrient Controllability: 1. Point sources--There were no known municipal wastewater treatment plants impacting Gull Lake during the sampling year. ------- 2 The Village of Pequot Lakes, about 8 miles north of Gull Lake, is served by stabilization ponds, but there is no discharge from the system (Schilling, 1975). Septic tanks serving shoreline dwellings were estimated to have contributed about 4% of the total phosphorus load to the lake, but a shoreline survey would be necessary to determine the actual significance of these sources. It is calculated that Gull Lake received a total phosphorus load at a rate less than that proposed by Vollenweider (in press) as an oligotrophic rate (see page 12). However, the existing trophic condition of the lake indicates that either the loading rate must have been higher in the past or the true loading rate was not determined by Survey sampling. It seems more likely that the latter is the case, and a need for further study of the lake is indicated. 2. Non-point sources--Survey data indicate that upper Gull Lake contributed nearly 51% of the total annual phosphorus load to the south basin of Gull Lake. The origin of the phosphorus load from upper Gull Lake is not known; but if the load could be significantly reduced, it is believed the water quality of the south basin of Gull Lake would be improved. ------- II. LAKE AND DRAINAGE BASIN CHARACTERISTICS A. Lake Morphometry : 1. Surface area: 9,540 acres. 2. Mean depth: 30 feet. 3. Maximum depth: 86 feet. 4. Volume: 286,200 acre-feet. 5. Mean hydraulic retention time: 2.9 years. B. Tributary and Outlet: (See Appendix A for flow data) 1. Tributaries - Drainage Mean Name area (mi2)* flow (cfs)* Dade Lake connection 8.5 3.7 Upper Gull Lake connection 200.0 98.2 Round Lake connection 52.6 19.9 Minor tributaries & immediate drainage - 20.0 13.0 Totals 281.1 134.8 2. Outlet - Gull River 296.0** 134.9 C. Precipitation***: 1. Year of sampling: 32.7 inches. 2. Mean annual: 27.5 inches. t Affeldt. 1971. * Drainage areas are accurate within ±5%; mean daily flows are accurate within ±10%; and ungaged flows are accurate within ±10 to 25% for drainage areas greater than 10 mi2. ** Includes area of lake. *** See Working Paper No. 1, "Survey Methods, 1972". ------- 4 III. LAKE WATER QUALITY SUMMARY Gull Lake was sampled three times during the open-water season of 1972 by means of a pontoon—equipped Huey helicopter. Each time, samples for physical and chemical parameters were collected from three stations on the lake and from a number of depths at each station (see map, page vi). During each visit, a single depth-integrated (15 feet to surface) sample was composited from the stations for phytoplankton identification and enumeration; and during the last visit, a single five-gallon depth- integrated sample was composited for algal assays. Also each time, a depth-integrated sample was collected at each of the stations for chloro- phyll a analysis. The maximum depths sampled were 60 feet at station 1, 40 feet at station 2, and 66 feet at station 3. The results obtained are presented in full in Appendix B, and the data for the fall sampling period, when the lake essentially was well- mixed, are summarized in the following table. Note, however, the Secchi disc summary is based on all samples. For differences in the various parameters at the other sampling times, refer to Appendix B. ------- 5 A. Physical and chemical characteristics: FALL VALUES (10/24/72) Parameter Minimum Mean Median Maximum Temperature (Cent.) 7.3 7.6 7.7 7.8 Dissolved oxygen (mg/i) 9.4 10.6 10.2 12.4 Conductivity ( imhos) 208 214 212 220 pH (units) 7.7 7.8 7.8 7.9 Alkalinity (mg/i) 99 105 105 107 Total P (mg/i) 0.017 0.034 0.037 0.052 Dissolved P (mg/i) 0.010 0.024 0.027 0.036 NO 2 + NO 3 (mg/i) 0.030 0.040 0.040 0.050 Ammonia (mg/i) 0.110 0.120 0.120 0.160 ALL VALUES Secchi disc (inches) 77 91 84 120 ------- 6 B. Biological characteristics: 1. Phytoplankton — Sampling Dominant Number Date Genera per ml 07/02/72 1. Tabellaria 1,392 2. Microcystis 958 3. Fragilaria 416 4. Oocystis 307 5. Flagellates 271 Other genera 688 Total 4,032 09/05/72 1. Microcystis 714 2. Anabaena 542 3. Dinobryon 443 4. Lyngbya 344 5. Aphanocapsa 316 Other genera 498 Total 2,857 10/24/72 1. Flagellates 2,906 2. Dinobryon 1 ,358 3. Fragilaria 981 4. Anabaena 868 5. Chroococcus 490 Other genera 2,831 Total 9,434 ------- 7 2. Chlorophyll a — (Because of instrumentation problems during the 1972 sampling, the following values may be in error by plus or minus 20 percent.) Sampling Station Chlorophyll a Date Number ( pg/i ) 07/02/72 01 17.6 02 13.1 03 10.2 09/05/72 Spike (mg/i ) Control 0.005 P 0.010 P 0.020 P 0.050 P 0.050 P + 10.0 N 10.0 N Maximum yield ( mg/i-dry wt. ) 2.4 2.3 2.5 2.6 2.7 29.5 5.4 2. Discussion - The control yield of the assay alga, Selenastrum capri- cornutum , indicates that the potential primary productivity of Lower Gull Lake was moderate at the time of sampling (10/24/72). Also, the results indicate the lake was nitrogen 10/24/72 01 8.3 02 4.8 03 8.8 01 19.1 02 16.3 03 14.0 C. Limiting Nutrient Study: 1. Autoclaved, filtered, and nutrient spiked - Ortho P Inorganic N ___________ Conc. (mg/i) Conc. (mg/i ) 0.029 0.131 0.034 0.131 0.039 0.131 0.049 0.131 0.079 0.131 0.079 10.131 0.029 10.131 ------- 8 limited at that time. No growth response accompanied spikes of phosphorus alone, but the addition of nitrogen alone stimu- lated growth significantly. The lake data substantiate nitrogen limitation at the time of assay sample collection (the N/P ratio was 6/1) but indicate phosphorus limitation In July (N/P 16/1) and September (N/P = 16/1). ------- 9 IV. NUTRIENT LOADINGS (See Appendix C for data) For the determination of nutrient loadings, the Minnesota National Guard collected monthly near-surface grab samples from each of the tributary sites indicated on the map (page vi), except for the high runoff months of April and May when two samples were collected. Samp- ling was begun in October, 1972, and was completed in September, 1973. Through an interagency agreement, stream flow estimates for the year of sampling and a “normalized” or average year were provided by the Minnesota District Office of the U.S. Geological Survey for the tributary sites nearest the lake. In this report, nutrient loads for sampled tributaries were calcu- lated from mean annual concentrations and mean annual flows. Nutrient loadings for “minor tributaries and immediate drainage” (“ZZ” of U.S.G.S.) were estimated by using the means of the nutrient concentrations in the Dade Lake connection (station B—i) and the Round Lake connection (station D-i) and the mean annual ZZ flow. ------- 10 A. Annual Total Phosphorus Loading - Average Year: 1. Inputs — lbsP/ %of Source yr total a. Tributaries (non-point load) Dade Lake connection 120 1.5 Upper Gull Lake connection 5,220 64.5 Round Lake connection 550 6.8 b. Minor tributaries & immediate drainage (non-point load) - 380 4.7 c. Known municipal STP’s - None — d. Septic tanks* - 330 4.1 e. Known industrial - None - f. Direct precipjtation** - 1,490 18.4 Total 8,090 100.0 2. Outputs - Lake outlet - Gull River 5,050 3. Net annual P accumulation — 3,040 pounds * Estimate based on 285 lakeshore dwellings and 25 resorts (Affeldt, 1971); see Working Paper No. 1. ** See Working Paper No. 1. ------- 11 B. Annual Total Nitrogen Loading - Average Year: 1. Inputs — lbsN/ %of Source yr total a. Tributaries (non-point load) Dade Lake connection 5,670 1.8 Upper Gull Lake connection 158,720 50.7 Round Lake connection 25,780 8.2 b. Minor tributaries & immediate drainage (non-point load) - 18,380 5.9 c. Known municipal STP’s - None - - d. Septic tanks* - 12,570 4.0 e. Known industrial - None - - f. Direct precipitation** - 91,910 29.4 Total 313,030 100.0 2. Outputs — Lake outlet - Gull River 193,070 3. Net annual N accumulation - 119,960 pounds * Estimate based on 285 lakeshore dwellings and 25 resorts (Affeldt, 1971); see Working Paper No. 1. ** See Working Paper No. 1. ------- 12 C. Mean Annual Non-point Nutrient Export by Subdrainage Area: In butary 1 bs P/mi 2 /yr 1 bs N/mi 2 /yr Dade Lake connection 14 667 Upper Gull Lake connection 26 794 Round Lake connection 10 490 D. 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 mor- phometry permitted. A mesotrophic rate would be considered one between “dangerous” and “permissible”. Total Phosphorus Total Nitrogen Total Accumulated Total Accumulated lbs/acre/yr 0.85 0.32 32.8 12.6 grams/m 2 /yr 0.10 0.04 3.7 1.4 Vollenweider loading rates for phosphorus (g/m 2 /yr) based on mean depth and mean hydraulic retention time of Gull Lake: “Dangerous” (eutrophic rate) 0.34 “Permissible” (oligotrophic rate) 0.17 ------- 13 V. LITERATURE REVIEWED Affeldt, Craig, 1971. Report on investigation of water quality of the Gull Lake Chain, Cass and Crow Wing Counties. MPCA, Minneapolis. Schilling, Joel, 1975. Personal communication (Pequot Lakes wastewater treatment system). MPCA, Minneapolis. Vollenweider, Richard A. (in press). Input-output models. Schweiz. Z. Hydrol. ------- VI APPENDICES APPENDIX A TRIBUTARY FLOW DATA ------- TP1HUTA Y FLOw iNFO MAT1ON FOP MINNESOTA 10/30/74 LAKE CODE 2737 GULL LAKE TOTAL DRAINAGE AREA OF LAKE 2q6.00 SUB—DRAINAGE NORMALIZED FLOWS TRIBUTARY AREA JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MEAN 2737A 1 296,00 125.20 123.80 131.90 197.20 186.70 189.40 129.00 91.50 97.60 106.30 108.90 131.90 134.90 273781 8.50 1.26 l.6 2.26 5.97 5.6 5.26 3.69 3.36 3.02 5.90 4.07 2.61 3.74 2737C 1 200.00 6.50 98.00 83.60 162.00 148.00 129.00 93.40 94.50 65.00 140.00 11.40 86.80 98.25 2737D1 52.60 4.33 6.39 10.30 39.60 33.80 32.80 22.10 17.80 14.40 26.50 20.00 10.00 19.87 2737ZZ 35.20 5.30 7.18 8.71 24.90 20.30 21.80 13.10 10.30 9.07 15.70 11.30 8.68 13.04 SUMMARY TOTAL DRAINAGE AREA OF LAKE 296.00 TOTAL FLOW IN = 1617.30 SUN OF SUB—DRAINAGE AREAS 296.30 TOTAL FLOW OUT = 1619.40 MEAN MONTHLY FLOWS AND DAILY FLOWS TRIBUTARY MONTH YEAR MEAN FLOW DAY FLOW DAY FLOW DAY FLOW 2737A1 10 72 111.00 15 BQ.00 11 72 359.00 18 370.00 1? 72 194.00 22 177.00 1 73 162.00 6 320.00 2 73 99.00 4 120.00 3 73 163.00 26 165.00 4 73 101.00 9 75.00 24 180.00 5 73 234.00 4 2 Q.00 20 100.00 6 73 97.00 11 180.00 7 73 162.00 13 100.00 8 73 218.00 17 340.00 9 73 94.90 17 40.00 273781 10 72 3.25 15 3.30 11 72 5.17 18 4.80 12 72 3.14 22 3.10 1 73 2.21 6 2.20 2 73 1.66 4 1.70 3 73 6.78 26 8.80 4 73 4.98 9 4.70 24 5.80 5 73 6.30 4 6.30 20 5.60 6 73 4.50 11 4.90 7 73 3.91 13 3.80 8 73 1.68 17 1.80 9 71 2.36 17 2.20 ------- T’JIr4IITARY FLU ’ 1 fO -1ATIUN FO ‘\iINNESOTA 10/30/74 A’(F CO )F 2717 ILL LAKE MEL bJ M J’JT— LY L ) ‘‘- A i;) IL ‘ T IPJTA Y ‘-I3NTH Yt.A - ft A FL H ‘AY FL J DAY FLOW DAY FLOW 7737C1 10 7 77•’fl 1 79.0) J 7 14c. 0 I L !3 -.0 ’ ) 1’ 77 1O- .(.,fl ? 10 ,.C0 1 73 114.”’ 117.0i 2 7 1 - “. ( ‘* 1O1.C) 3 3 ? 1.’ifl 2 3? • (j 4 73 1 3 . O 9 12 .0O 24 1 7.00 73 )6 . ’0 4 16S.00 ?O 147.00 7 11.’ (‘ 1) 120.00 7 73 ‘ °.O0 13 47.00 73 47.2C 17 ‘ 0.00 9 73 “.7O 17 +l.00 ?737fl 1 10 11 1 1 7 1 4 S 6 7 Q 72 72 72 73 7_ 73 73 7 7 71 71 73 -5.40 1’.’ 0 7. ‘.. 3 .L0 33 .’Q 37•. 0 2 -4.13 23• . 11.?0 1 1 ’ 72 f 4 9 4 11 i: 17 17 IS.0’) ? +,Oo 12.00 7.60 e.60 40.0’) 11.00 3fj.00 31.00 23.00 9.40 10.0 24 20 38.00 34.00 273777 JO 11 J7 1 7 3 4 5 6 7 7 - ’ 77 73 71 71 71 73 7 73 7. .‘-7 1 .4’, 1C.511 u.2t: 7.43 ?c.70 IP.”-) s .i 7 17 1’- 1 ? 4 ? 4 11 13 11 17 - .0 13.0’) 10.0 ) - ‘.1G 7•4 34.0) 1 i.00 23.00 20.00 1’+.0 ) 5.50 6.E0 24 2C 2’..00 20.00 ------- APPENDIX B PHYSICAL and CHEMICAL DATA ------- STORET RETRIEVAL DATE 74/10/30 273701 46 28 42.0 094 19 12.0 GULL LAKE 27 MINNESOTA 11EPALES 2111202 3 0060 FEET DEPTH 00010 00300 00077 00094 00400 00410 00630 00610 00665 00666 DATE TIME DEPTH WATER DO TRANSP CNDUCTVY PH T ALK NO2 NO3 NH3—N PHOS—TOT PHOS—DIS FROM OF TEMP SECCHI FIELD CACO3 N—TOTAL TOTAL TO DAY FEET CENT MG/L INCHES MICROMHO SU MG/L MG/L MG/L MG/L P MG/I P 72/07/02 11 05 0000 21.0 8.2 120 190 8.50 100 0.040 0.040 0.022 0.009 11 05 0015 17.5 8.2 195 7.90 101 0.040 0.040 0.022 0.009 11 05 0030 11.5 4.3 205 7.30 104 0.160 0.040 0.014 0.010 11 05 0060 8.0 1.0 210 7.00 118 0.300 0.160 0.049 0.029 72/09/05 13 27 0000 18.8 108 195 8.55 95 0.050 0.070 0.013 0.008 13 27 0004 18.8 8.5 190 8.55 93 0.040 0.060 0.013 0.007 13 27 0015 18.4 8,0 190 8.55 94 0.040 0.050 0.011 0.007 13 27 0030 17.4 6.4 195 8.15 119 0.040 0.050 0.011 0.007 13 27 0045 11.3 0.4 218 7.30 123 0.050 0.240 0.045 0.013 72/10/24 13 30 0000 77 210 7.80 106 0.040 0.120 0.017 0.010 13 30 0004 7.7 9.9 208 7.80 105 0.040 0.120 0.034 0.025 13 30 0015 7.7 10.2 208 7.80 107 0.040 0.120 0.043 0.029 13 30 0025 7.5 10.2 210 7.80 107 0.040 0.120 0.041 0.030 13 30 0035 7.3 9.4 208 7.70 107 0.040 0.120 0.044 0.032 13 30 0046 7.5 10.0 212 7.70 107 0.040 0.120 0.052 0.036 32217 DATE TIME DEPTH CHLRPHYL FROM OF A TO DAY FEET UG/L 72/07/02 11 05 0000 17.6J 72/09/05 13 27 0000 8.3J 72/10/24 13 30 0000 19. IJ J VALUE KNOWN TO BE IN ERROR ------- ST3PET ‘ ETR1FvAL DATE 74/10/30 ‘7370? 46 ? 4M.0 094 20 3’..0 hULL LAXE 27 M INNFSOTA 1IEPALES 2111202 3 0045 FEET DEPTH 00010 00 0 00077 00094 00400 00410 00630 00 ’St O 00665 00666 OATF TIu r)FPT-4 ATE 1)0 19AJ’ISP CNDIICTVY Pr4 r ALt( NO2 NO3 NH3-N P’iOS—TOT Pi- OS—L)1S FROM OF TEMP SECCHI FIFLI) CACO3 N—TOTAL TOTAL TO DAY FET CENT M( /L INC’4ES MICROMI-40 SU M6/L MG/L MG/L H&/L P MG/L P 7?/07/07 11 30 0000 ‘l. 7. P4 190 99 0.050 0.040 0.020 0.010 11 10 0024 15.0 7.0 200 104 0.060 0.050 0.023 0.010 11 30 0040 9•5 1.2 ?OS 104 0.260 0.080 0.154 0.012 7?/o9/O 11 01 0000 IM.’ 9f 190 8.50 Il ? 0.040 0.060 0.018 0.010 13 01 0004 1 .S 187 8.50 112 0.040 0.040 0.017 0.008 13 03 0015 !F .0 7.6 19C 8.40 110 0.040 0.050 0.012 0.008 I] 03 0030 17. ‘.6 195 4.3O 111 0.040 0.050 0.013 0.007 7?/I0/?4 14 05 00’ 0 78 220 7.90 105 0.040 0.110 0.017 0.011 1’. 05 0004 7. 12.4 21? 7.90 106 0.040 0.110 0.034 0.023 14 05 0015 7.5 11.0 218 7.90 105 0.040 0.110 0.030 0.022 3??1 7 nATE TIME OEQTH CHL PHYL FPOM OF A T ) hAY FFFT ‘JG/L 7?/07/0’ II 10 0000 13.LJ 7?/09/OS I l 01 0000 4.HJ 72/10/24 14 05 0000 1€.3J J ALIJE KNOWN TO E I ’i F.? Q). ------- STORET RETRIEVAL DATE 74/10/30 273703 46 25 42.0 094 21 57.0 GULL LAKE 27 MINNESOTA 1 1EPALES 2111202 3 0050 FEET DEPTH 00010 00300 00077 00094 00400 00410 00630 00610 00665 00666 DATE TIME DEPTH WATER DO TRANSP CNDUCTVY PH T ALK P’402&N03 NH3—N PHOS—TOT PHOS—OIS FROM OF TEMP SECCHI FIELD CACO3 N—TOTAL TOTAL TO DAY FEET CENT MG/L INCHES MICROMHO SU MG/L MG/L MG/I MG/I P MG/L P 72/Ô7/02 12 00 0000 21.5 8.8 78 195 8.40 98 0.040 0.050 0.015 0.010 12 00 0015 21.0 8.6 107 0.040 0.060 0.026 0.015 12 00 0040 9.0 1.8 210 7.20 107 0.310 0.040 0.015 0.011 72/09/05 11 55 0000 18.2 96 190 8.40 108 0.050 0.120 0.014 0.011 11 55 0004 18.2 6.7 190 8.45 108 0.040 0.050 0.014 0.008 11 55 0015 17.9 8.0 185 8.40 108 0.050 0.050 0.014 0.007 11 55 0030 16.3 3.1 215 7.30 118 0.030 0.050 0.013 0.009 11 55 0045 11.1 0.4 220 7.20 119 0.030 0.270 0.040 0.031 11 55 0066 9.7 0.0 200 7.50 119 0.070 0.850 0.082 0.020 7?/10/24 14 30 0000 84 220 7.80 99 0.040 0.120 0.019 0.011 14 30 0004 7.8 10.3 212 7.80 99 0.040 0.110 0.032 0.023 14 30 0015 7.7 9.9 220 7.80 99 0.030 0.110 0.036 0.027 14 30 0025 7.7 9.9 210 7.80 105 0.040 0.130 0.037 0.025 16 30 0035 7.7 10.2 210 7.80 14 30 0045 7.7 10.3 212 7.80 105 0.040 0.130 0.041 0.028 14 30 0055 7.7 9.6 220 7.80 105 0.040 0.140 0.037 0.028 14 30 0062 7.7 10.4 220 7.70 106 0.050 0.160 0.047 0.035 32217 DATE TIME DEPTH CHLRPHYL FROM OF A TO DAY FEET UG/L 72/07/02 12 00 0000 10.2J 72/09/05 11 55 0000 R.8J 72/10/24 14 30 0000 14.OJ J VALUE K 4O W TO F t QPQ ------- APPENDIX C TRIBUTARY DATA ------- ST jQET ETQIEVAL DATE 74/101)0 2737A1 LS273741 46 25 00.0 094 21 30.0 GULL RIVER 27 Co 011, SHEET 01 0/GULL LAPcF (CASS CO) CO HWY 105 1 PDG N OF EAST GULL LAKE 1 1EPALES 2111204 4 0000 FEET DEPTH OOe,30 006?S 00610 00671 00665 DATE TIME DEPTH N02 NO3 TOT KJEL NHI—N PHOS—DIS PHOS—TOT FROM 0 N-TOTAL N TOTAL ORTHO TO DAY FEET MG/L 1G/L HG/L MG/L P MG/L P 72/10/15 10 50 0.0 6 0.450 0.044 0.005K 0.019 7?/11/18 1400 0.020 0.c40 0.019 0.005K 0.018 7?/I?/?? 09 40 0.0)5 0.560 0.034 0.005K 0.013 71/01/06 09 15 0.037 0.S 0 0.058 0.005K 0.020 73/O?/04 10 0’) 0.048 0.690 0.039 0.005K 0.010 71/03/?6 14 45 0.072 1.050 0.0 0 0.015 0.020 71/04/09 14 IS 0.025 2.100 0.039 0.005K 0.020 73/04/24 14 25 0.015 0.440 0.008 0.005K 0.020 73/05/04 10 20 ( 1.015 0.480 0.006 0.011 0.020 71/05/20 13 30 0.010K 0.610 0.006 0.007 0e025 73/06/11 10 55 0.010K 0.720 0.010 0.005P 0.020 73/07/13 15 35 0.010K 0.580 0.017 0.005K 0.015 71/08/17 14 10 0.010K 0.330 0.020 0.014 0.020 71/09/17 13 50 0.025 0.670 0.050 0.009 0.025 K VALUE r NOt N TO r3E LESS THAN INDICATED ------- STOPET r ETR1EVAL DATE’ 7 ./19/30 2737 3 1 ‘.6 23 LOwER 27 TI GULL Co HWY 1 IEPALES 4 L52737 U 00.0 094 22 00.0 GULL UK/DADE LAKE CONNECT! Co Wil, SHEET *1 LAKE (CASS CO) 77 XING SW OF EAST GULL LAKE 2111204 0000 FEET DEPTH 00h3 00675 00610 00671 00665 DATE TIME DEPTH NO?€ !O3 TOT KJEL NH3—N PHOS—DIS PHOS—TOT FPC)M (W N-TOTAL N TOTAL OPT’-40 TO DA FEET MG/L AG/L MC /L Mc /L P MG/L P 7?/)0/15 10 30 0.6 5 0.056 0.005K 0.014 7 2/Il/l U 13 50 0.011 0.760 0.06? 0.005K 0.011 7?/I2/2? I I 45 O. ?0 0.043 0.005K 0.01 71/0l/0 10 0() C.014 0.B40 0.04 0.005K 0.010 71/02/04 13 ( 10 0.01 1.100 0.071 0.00 5K 0.010 71/03/? l’ 30 .0 70 1.750 0.078 0.010 0.020 71/04/09 14 00 0.010K 1. 60 0.010 0.00 5K 0.070 73/04/24 11 10 0.010K 0.5 O 0.00 5K 0.005K 0.020 71/05/0’ 10 00 0.010K 0.665 0.005K 0.006 0.02SK 71/05/20 10 00 3.0 )0K 0.570 0.011 0.006 0.01 , 71/06/11 10 35 ( 1 . O1OK 0.790 0.009 0.005K 0.015 71/07/13 14 Of) 0.01 0K 0.700 0.014 0.00 5K 0.020 71/0 4/17 14 00 0.013K 0.660 0.030 0.020 0.030 71/09/17 11 00 0.010’( 0.-30 0.029 0.007 0.010 1< VALUI- NOt TO BE LESS P-1i N I OIC TED ------- STOPET PETPIF.VAL DATE 74/10/30 2737C1 LS2737C1 46 30 30.0 094 20 30.0 UPPER GULL LK/GULL LK CONNECTION 27 Co #11, SHEET $1 1/GULL LAKE (CASS CO) CO HWY 77 BROG AT VLG OF LAKE SHORE I IEPALES 2111204 4 0000 FEET DEPTH 00630 00625 00610 00671 00665 DATE TIME 1)EPTr4 NO2 ,NO3 TOT KJEL NH3-N Pr-40S—DIS PHOS—TOT FROM OF N—TOTAL N TOTAL URTHO TO DAY FEET MG/L - HG/L MG/I MG/L P MG/L P 7?/I0/15 11 10 0.0’+5 0.700 0.060 0.005 k 0.O2f, 7?/Il/ IM 14 30 0.065 0.5 0 0.056 0.006 0.021 7?/I2/ 2 10 00 0.115 0.560 0.048 0.005K 0.016 73/01/06 09 00 0.189 0.7 0 0.057 0.005K 0.020 73/0?/04 14 00 0.252 0.540 0.027 0.005K 0.015 73/O4/0 14 40 0.010< 1.000 0.011 0.008 0.050 71/04/?4 14 00 0.08? 0.660 0.032 0.005K 0.040 71/05/04 10 50 0.010K 0.640 0.005K 0.006 0.030 73/05/20 11 10 0.010K 0.650 0.008 0.007 0.025 73/06/11 11 20 0.010K 1.600 0.084 0.005K 0.020 71/07/13 15 00 0.010K 0.780 0.010 0.00 5K 0.025 71/08/17 14 30 0.010K 0.700 0.018 0.012 0.035 73/09/17 13 75 0.010K 0.7’0 0.024 0.008 0.025 K VALUE KNOWN TO BE LESS THAN INDICATED ------- STOPET I T IEVAL OAT 74/10/30 2737D1 LS2737D1 41 ’ 2 00.0 094 1R 00.0 ( ULL LK/ROUND LK CONNECTION 27 CO S’-IEET #2 1/ OLL LAKE (CASS CO) US i- WY 371 XING 1 1FPALES £4 2111204 0000 FEET DEPTH oO 3J OOf ’!S Or,610 00671 00665 DATE TIME DFPr-4 JO? ,MO3 TOl KJEL Nr-13N HOS—D!S PHOSTOT p?OM 1W N—TOTAL N TOTAL OPTHO TO DAY FFET 1C,/L iG/L f4 /L MG/L P MG/L r 7? /1O/15 ii 00 0.070 O.4’ S .066 0.005K 0.u1S 77/1I/1 14 15 0.010K 0.46 0 0.01 0.005K o.eoa 7?/I?/27 10 30 C.OlDrc 0.400 0.001’ 0.005K 0.012 73/01/01’ 09 30 fl.O1O’ 0.440 C..C?0 O.00 K 0.015 73/02/04 13 45 •D. O lcic 0. ’0O 0.017 0.005K 0.005K 73/01/21’ 15 00 0.O ljK 1.000 0.046 0.007 0.010 71/0 /0 14 30 0.010 K 1.760 0.009 0.005K 0.010 73/ 4/?4 14 00 o.Oi0c 0.400 0.005K 0.005K 0.015 71/0S/0 ’ 10 11’ 0.010K 0. ’” 0 0.005K 0.006 0.020 73/0 ,120 10 40 .01OK 0. 40 0.005K 0.006 0.015 71/01’/11 11 07 0.010K 1.100 0.010 0.005K 0.015 73/07/1 ) 15 15 0.010K 0.540 0.009 0.005K 0.015 71/OR/17 14 20 0.010K 0.500 0.016 0.00 0.0?0 73/09/li 13 35 0.010K 0.5’O 0.012 0.005K 0.015 K Vf,LUE r’NO NJ TO BE LESS T- A J INDIC TEI) ------- |