U.S. ENVIRONMENTAL PROTECTION AGENCY NATIONAL EUTROPHICATION SURVEY WORKING PAPER SERIES REPORT ON BIRCH LAKE CASS COUNTY MINNESOTA EPA REGION V WORKING PAPER No, PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY An Associate Laboratory of the NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON and NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA •trOFO 697.032 ------- REPORT ON BIRCH LAI€ CASSCOMY MINNESOTA EPA REGION V WORKING PAPER No, 145 WITH THE COOPERATION OF THE MINNESOTA POLLUTION CONTROL AGENCY AND THE MINNESOTA NATIONAL GUARD JANUARY, 1975 ------- I CONTENTS Page Foreword ii List of Minnesota Study Lakes iv, v Lake and Drainage Area Map vi Sections I. Introduction 1 Ii. Conclusions 1 III. Lake Morphometry 2 IV. Precipitation 2 V. Lake Water Quality Sumary 3 VI. Appendix 8 ------- 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 reservoi rs. 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 [ 5303(e)], water quality criteria/standards review [ 5303(c)], clean lakes [ 5314(a,b)], and water quality monitoring [ 5106 and §305(b)] activities mandated by the Federal Water Pollution Control Act Amendments of 1972. * The lake discussed in this report was included in the National Eutrophication Survey as a lake of special interest to the Minnesota Pollution Control Agency. For this reason, tributaries and nutrient sources were not sampled, and this report relates only to data ob- tained from lake sampling. ------- lii 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 als9 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 Beltraml 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 Hornnie 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 Wallmark Chisago White Bear Washington Winona Douglas Wolf Beltrami, Hubbard Woodcock Kandiyohi Zumbro Olrnstead, Wabasha ------- C 2IRCH LAKE Pj Loc. rs BIRCH LAKE )c 01 ...I 1sie 5 Pnplin 5 t sft.t c2 ------- BIRCH LAKE STORET NO. 2710 I. INTRODUCTION Birch Lake was included in the National Eutrophication Survey as a water body of interest to the Minnesota Pollution Control Agency. Tributaries and nutrient sources were riot sampled, and this report relates only to data obtained from lake sampling. II. CONCLUSIONS A. Trophic Condition: Survey data indicate that Birch Lake is eutrophic. Of the 60 Minnesota lakes sampled in the fall when essentially all were well—mixed, 11 had less mean total phosphorus, 16 had less mean dissolved phosphorus, but none had less mean inorganic nitrogen. Of the 80 Minnesota lakes sampled, nine had less mean chlorophyll a, and 10 had greater Secchi disc transparency. Near depletion of oxygen with depth occurred at station 2 in July and September. B. Rate—Limiting Nutrient: The algal assay results show that Birch Lake was nitrogen limited at the time the sample was collected. However, the lake data indicate phosphorus limitation in September (N/P ratio = 24/1) but a borderline condition in July (N/P = 13/1). * DNR lake survey map (1957). ------- 2 III. LAKE MORPHOMETRY* A. Surface Area: 1,283 acres. B. Mean Depth: 10 feet. C. Maximum Depth: 45 feet. D. Volume: 12,830 acre feet. IV. PRECIPITATION A. Year of Sampling: 26.7 inches. B. Mean Annual: 23.8 inches. * DNR lake survey map (1957). ------- V. LAKE WATER QUALITY SUMMARY Birch 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 two stations on the lake and from one or more depths at each station (see map, page vi). During each visit, a single depth-integrated (15 feet or near bottom 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 from each of the sta- tions for chlorophyll a_ analysis. The maximum depths sampled were 4 feet at station 1 and 34 feet at station 2. The results obtained are presented in full in the Appendix, and the data for the fall sampling period, when the lake essentially was well- mixed, are summarized below. Note, however, the Secchi disc summary is based on all values. For differences in the various parameters at the other sampling times, refer to the Appendix. ------- 4 A. Physical and chemical characteristics: FALL VALUES (10/24/72) Parameter Minimum Mean Median Maximum Temperature (Cent.) 3.1 4.9 5.4 5.4 Dissolved oxygen (mg/i) 10.8 11.3 11.0 12.8 Conductivity (pmhos) 190 207 210 210 pH (units) 8.2 8.2 8.2 8.5 Alkalinity (mg/i) 98 105 106 107 Total P (mg/l) 0.015 0.029 0.030 0.037 Dissolved P (mg/l) 0.009 0.019 0.020 0.026 NO + NO (mg/i) 0.020 0.023 0.020 0.030 AJonia mg/l) 0.020 0.023 0.020 0.040 ALL VALUES Secchi disc (inches) 54 96 90 168 ------- 5 B. Biological characteristics: 1. Phytoplankton - Sampling Dominant Number Date Genera per ml 07/12/72 1. Dinobryon 1,628 2. Microcystis 253 3. Cyclotella 229 4. Anabaena 109 5. Navicula 96 Other genera 182 Total 2,497 09/08/72 1. Chroococcus 1,315 2. Flagellates 693 3. Dinobryon 231 4. Anabaena 90 5. Cryptornonas 60 Other genera 272 Total 2,661 10/24/72 1. Flagellates 2,035 2. Dinobryon 1,533 3. Fragilaria 427 4. Anabaena 201 5. Cryptonionas 176 Other genera 1 4O6 Total 5,778 ------- 6 Spike (mg/i ) Con troi 0.005 P 0.010 P 0.020 P 0.050 P 0.050 P + 10.0 N 10.0 N 02 01 02 01 02 and nutrient spiked - Inorganic N Conc. (mg/i ) 0.100 0.100 * 0.100 0.100 0.100 10.100 Maximum yield N/P ( mg/i-dry wt.) Ratio 1.4 6/1 1.4 - 1.3 - 1.4 - 1.6 - 27.3 151/1 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 ) 07/12/72 01 11.7 09/08/72 1.5 4.0 10/24/72 4•9 8.8 C. Limiting Nutrient Study: 1. Autoclaved, filtered, Ortho P ___________ Conc. (mg/i ) 0.017 0.022 0.027 0.037 0.067 0.067 (not done) 2. Discussion — The control yield of the assay alga, Selenastrum capri- cornutum , indicates that the primary productivity of Birch Lake was moderate at the time the sample was collected. Also, the lack of significant changes in yields with increasing increments of phosphorus, until nitrogen also was added, indi- cates that Birch Lake was nitrogen limited at the time of ------- 7 sampling. The nitrogen/phosphorus ratio in the lake when the sample was collected (about 2.5 to 1) confirms this conclusion. However, the N/P ratio of about 24 to 1 in the September lake sample indicates that Birch Lake may also be phosphorus limited at times (this has been ob- served in some other Survey lakes, including Shagawa Lake). ------- VI. APPENDIX ------- STOPET RETRIEVAL DATE 74/10/30 271001 46 56 00.0 094 31 30.0 BIRCH LAKE 27 MINNESOTA 11EPALES 2111202 4 0004 FEET DEPTH 00010 00300 00077 00094 00400 00410 00630 00610 00665 00666 DATE TIME OE”TH ATFR 00 TPA! JSP CNDUCTVY PM I ALK N02&N03 NH3—N PHOS—TOT PHOS—DIS FROM OF TEMP SECCHI FIELD CACO3 N—TOTAL TOTAL TO DAY FEET CENT ‘1G/L INCHES MICROMMO SU NG/ 14G/L MG/I .. MG/L P MG/L P 7?/07/1? 17 50 0000 72 17 50 0004 24.2 10.? 150 8.40 124 0.040 0.040 0.019 0.008 72/09/08 14 40 0000 19.5 9.9 E 0 180 8.70 88 0.050 0.100 0.012 0.008 72/10/24 09 05 0000 3.1 1?.8 5’. 190 8.50 98 0.030 0.040 0.015 0.010 3?717 DATE TIME DEPTH CHL PHYL FROM OF A TO DAY FEET IJG/L 72/07/1? 17 50 0000 l1.7J 72/09/OM 14 40 0000 1.5J 7?/10/24 09 05 0000 4 JJ J VALUE KNOWN TO HE jN RR0 ------- STORET RETpTF VAL DATE 74/1 J/ 271002 46 56 45.0 094 32 30.0 eIRCH LAKE 27 MINNESOTA I IEPALES 4 2111202 0024 FEET DEPTH 00019 00300 00077 00094 00400 00410 00630 00610 00665 00666 D 1 E TIMF DEPTH WATEP (30 T’ ANSP CNDIJCTVY PH T ALK N02&N03 NM3—N PHOS—TOT PHOS—DIS FROM OF TEMP SECCHI FIELD CAC03 N—TOTAL TOTAL TO Day FEET CENT ‘ G/L INCHES MICROMHO SU MG/L MG/L MG/L M&L P MG/L P 72/07/12 IA 05 0000 168 IH 05 0004 23 .7 f•4 180 7.90 102 0.030 0.040 0.013 0.008 IA 05 0015 ‘1. 6.4 190 7.60 109 0.040 0.050 0.018 0.013 I A 05 0024 11.7 u.6 205 6.50 117 0.050 0.180 0.015 0.008 72/09/08 14 00 0000 108 215 7.95 111 0.050 0.080 0.019 0.010 14 00 000” 19.3 .O 210 7.90 108 0.050 0.060 0.018 0.007 14 00 0015 18.5 7.7 215 7.90 106 0.050 0.060 0.017 0.006 14 00 0020 1F.4 7•c 215 7.85 105 0.040 0.060 0.016 0.007 14 00 0027 1’.O l. A 225 7.20 115 0.040 0.120 0.021 0.015 14 00 0034 3.Q ‘.3 265 7.10 129 0.080 0.680 0.064 0.007 72/10/24 09 25 oOQØ 115 210 8.20 105 0.020 0.020 0.033 0.023 (19 25 0004 5. ’ . 10.8 710 8.2 o 105 0.020 0.020 0.034 0.026 09 25 0015 5. . 1 1.0 ‘10 8.20 106 0.020 0.020 0.037 0.026 09 25 0027 5.4 11.0 210 8.20 107 0.020 0.020 0.027 0.018 09 ?5 0929 5. 1 Ifl.8 210 8.20 106 0.030 0.020 0.027 0.009 DATE TIMF D PT9 3”l 7 C - L . PHYL EPOM OF TO I)AY FEET ‘J /L 72/09/OH 14 00 000’) ..JJ 72/10/24 09 “ 000’) J VALUE KNOW’ TO r L I PP 0 ------- |