U.S. ENVIRONMENTAL PROTECTION AGENCY NATIONAL EUTROPHICATION SURVEY WORKING PAPER SERIES REPORT ON 11ASHKENODE LAKE ST, UDUIS COUNTY MINNESOTA EPA REGION V WORKING PAPER No, 111 PACIFIC NORTHWEST ENVIRONMENTAL RESEARCH LABORATORY An Associate Laboratory of the NATIONAL ENVIRONMENTAL RESEARCH CENTER - CORVALLIS, OREGON and NATIONAL ENVIRONMENTAL RESEARCH CENTER - LAS VEGAS, NEVADA ------- REPORT ON HASHKhNODE LAKE ST, IMS COUNTY MINNESOTA EPA REGION V WORKING PAPER No, 111 WlTH THE COOPERATION OF THE MINNESOTA POLLUTION CONTROL AGENCY AND THE MINNESOTA NATIONAL GUARD DECEMBER, 1974 ------- 1 CONTENTS Page Foreword ii List of Minnesota Study Lakes iv, 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 14 VI. Appendices 15 ------- 11 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 [ 314(a,b)], and water quality monitoring [ g106 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. ACKNOWL EDGMENT 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 Koochi chi ng 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 Homme 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 Beltrami, Hubbard Woodcock Kandiyohi Zumbro Olmstead, Wabasha ------- nnesota Map Location MASHKENODE LAKE ® Tributary Sampling Site X Lake Sampling Site Sewage Treatment Facility — — Direct Drainage Area Limits 1/2 !ML -L ( S Tr.atvn.n Focility near Evekth 2.5 Mi ------- MASHKENODE LAKE STORET NO. 2756 I. CONCLUSIONS A. Trophic Condition: Survey data indicate that Mashkenode Lake is eutrophic. Of the 60 Minnesota lakes surveyed in the fall of 1972, when essen- tially all were well—mixed, 30 had less mean total phosphorus, 15 had less mean dissolved phosphorus, and 11 had less mean in- organic nitrogen. Of the 80 Minnesota lakes sampled, 43 had greater Secchi disc transparency, and 49 had less mean chloro- phyll a. Survey limnologists noted that water quality was generally poor on all visits. High turbidity, anaerobic conditions with hydrogen sulfide evident, and intensive algal blooms and large areas of floating macrophytes were observed. B. Rate-Limiting Nutrient: The results of the algal assay show that nitrogen was the limiting nutrient at the time the sample was collected. The lake data also indicate that nitrogen was limiting at the other sampling periods (N/P ratios were less than 8/1 on all occasions). C. Nutrient Controllability: 1. Point sources--During the sampling year, Mashkenode Lake received a total phosphorus load at a rate more than six times ------- 2 that proposed by Vollenweider (in press) as hdangerousu; i.e., a eutrophic rate (see page 13). Of that load, it is estimated the Nichols Township wastewater treatment plant contributed nearly 88%. It is calculated that complete removal of phosphorus at the point source would reduce the loading rate to 5.8 lbs/acre/yr or 0.65 g/m 2 fyr (a mesotrophic rate). If 100% removal can be accomplished, the trophic condition of Mashkenode Lake should improve. 2. Non—point sources (see page 13)——The phosphorus export of the unnamed stream (B-i) compares well with the mean phosphorus export of five unimpacted tributaries of nearby Swan Lake* (28 lbs/ mi 2 /yr). In all, it is estimated that non-point sources contributed about 12% of the total phosphorus load to the lake during the sampling year. * Working Paper No. 129. ------- II. LAKE AND DRAINAGE BASIN CHARACTERISTICS A. Lake Morphometry : 1. Surface area: 101 acres. 2. Mean depth: 7 feet. 3. Maximum depth: 14 feet. 4. Volume: 707 acre/feet. 5. Mean hydraulic retention time: 40 days. B. Tributary and Outlet: (See Appendix A for flow data) 1. Tributaries - Name Unnamed stream (B-l) Minor tributaries & immediate drainage - Totals 2. Outlet - Two Rivers C. Precipitation***: 1. Year of sampling: 29.8 inches. 2. Mean annual: 26.9 inches. Drainage area* Mean flow* 16.7 mi2 8.6 cfs 0.7 mi .2 17.4 mi .2 0.4 cfs 9.0 cfs 17.6 mi2** 9.0 cfs** t DNR lake survey map (1964). * 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 mi^. ** Includes area of lake; outflow adjusted to equal sum of inflow. *** See Working Paper No. 1, "Survey Methods". ------- 4 III. LAKE WATER QUALITY SUMMARY Mashkenode 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 or more depths at one station on the lake (see map, page vi). During each visit, a single depth—integrated (near bottom to surface) sample was collected for phytoplankton identification and enumeration; and during the last visit, a single five-gallon depth-integrated sam- ple was collected for algal assays. Also, each time a depth-integrated sample was collected for chlorophyll a analysis. The maximum depth sam- pled was 12 feet. The results obtained are presented in full in Appendix B, and the data for the fall sampling period, when the lake was essentially 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 tines, refer to Appendix B. ------- 5 A. Physical and chemical characteristics: FALL VALUES (10/19/72) Parameter Minimum Mean Median Maximum Temperature (Cent.) 3.8 3.8 3.8 3.8 Dissolved oxygen (mg/l) 12.0 12.0 12.0 12.0 Conductivity (pmhos) 300 300 300 300 pH (units) 8.7 8.7 8.7 8.7 Alkalinity (mg/l) 87 89 88 92 Total P (mg/i) 0.050 0.053 0.052 0.058 Dissolved P (mg/i) 0.016 0.018 0.019 0.019 NO + NO (mg/l) 0.040 0.040 0.040 0.040 Arn onia mg/1) 0.070 0.077 0.080 0.080 ALL VALUES Secchi disc (inches) 36 41 42 46 ------- 6 B. Biological characteristics: 1. Phytoplankton - Sampling Dominant Number Date Genera per ml 07/10/72 1 . Cyclotella 904 2. Oocystis 832 3. Asterionella 687 4. Fragilaria 452 5. Flagellates 307 Other genera 1 ,321 Total 4,503 09/09/72 1 . Microcystis 6,396 2. Aphanocapsa 5,766 3. Peridinium 2,432 4. Dictyosphaerium 1,261 5. Ana aena 811 Other genera 4,054 Total 19,459 10/19/72 1. Cyclotella 15,639 2. Flagellates 2,632 3. Fragilaria 2,030 4. Cylindrocystis 1,654 5. Anabaena 827 Other genera 4,286 Total 27,068 ------- 7 Maximum yield ( mg/i-dry wt. ) 2.6 2.7 2.4 2.4 2.4 32.2 9.2 24 . 3 13.7 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 ) 07/10/72 01 09/09/72 01 10/19/72 01 37.9 C. Limiting Nutrient Study: 1 . Autoclaved, filtered, and nutrient spiked - Ortho P Inorganic N ___________ Conc. (mg/i) Conc. (mg/i ) _____________ 0.017 0.100 0.022 0.100 0.027 0.100 0.037 0.100 0.067 0.100 0.067 10.100 0.017 10.100 Spike (mall ) ____________ ____________ ______________ Control 0.005 P 0.010 p 0.020 P 0.050 P 0.050 P + 10.0 N 10.0 N 2. Discussion - The control yield of the assay alga, Selenastrum capri- cornutum , indicates that Mashkenode Lake had a moderately high rate of primary productivity at the time the assay sam- ple was collected. The lack of change in yield when phosphorus spikes were increased and the significant increase in yield when only nitrogen was added show nitrogen limitation. ------- 8 The lake data at each of the three sampling times indi- cate nitrogen limitation; i.e., the N/P ratios were less than 8/1, and nitrogen limitation would be expected. ------- 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 tribu- tary sites indicated on the map (page vi), except for the high runoff months of May and August when two samples were collected. Sampling 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 Minne- sota 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 loadings for unsampled “minor tributaries and immediate drainage” (“ZZ” of U.S.G.S.) were estimated by using the means of the nutrient loads, in lbs/mi 2 /year, in nearby Swan Lake tributaries at stations B-l , C-i, G-1 , H-i, and J-l and multiplying the means by the ZZ area in mi 2 . Nichols Township did not participate in the Survey and nutrient loads were estimated at 2.5 lbs P and 7.5 lbs N/capita/year. * See Working Paper No. 1. ------- 10 A. Waste Sources: 1. Known municipa1 - Pop. Mean Receiving Name Served Treatment Flow (mgd) Water Nichols 1 ,702* stab. pond 0.170** Creek to Township Mashkenode Lake 2. Known industrial - None t Anonymous, 1974. * 1970 Census. ** Estimated at 100 gal/capita/day. ------- 11 B. Annual Total Phosphorus Loading - Average Year: 1. Inputs - lbsP/ %of Source yr total a. Tributaries (non-point load) - Unnamed Creek (B-i) 550 11.4 b. Minor tributaries & immediate drainage (non-point load) - 20 0.4 c. Known municipal — Nichols Township 4,260 87.8 d. Septic tanks - None e. Known industrial - None - f. Direct precipitation* - 20 0.4 Total 4,850 100.0 2. Outputs - Lake outlet - Two Rivers 1 ,250 3. Net annual P accumulation - 3,600 pounds * See Working Paper No. 1. ------- 12 C. Annual Total Nitrogen Loading - Average Year: 1 Inputs - lbs NI % of Source yr total a. Tributaries (non-point load) - Unnamed Creek (B-i) 20,950 60.5 b. Minor tributaries & immediate drainage (non-point load) - 820 2.4 c. Known municipal Nichols Township 12,760 36.9 d. Septic tanks - None e. Known industrial - None - - f. Direct precipitation* - 970 0.2 Total 35,500 100.0 2. Outputs - Lake outlet - Two Rivers 15,580 3. Net annual N accumulation - 19,920 pounds * See Working Paper No. 1. ------- 13 D. Mean Annual Non-point Nutrient Export by Subdrainage Area: Tributary lbs P/m1 2 /yr lbs N/mi 2 Jyr Unnamed Creek (B-i) 33 1 ,254 E. Yeariy Loading Rates: In the following table, the existing phosphorus loading rates are compared to those proposed by Volienweider (in press). Essentially, his “dangerous” rate is the rate at which the receiving waters would become eutrophic or remain eutrophic; his pernissib1e 11 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 Units Total Accumulated Total Accumulated lbs/acr /yr 48.0 35.6 351.5 197.2 grams/rn /yr 5.38 4.00 39.4 22.1 Volle 2 weider loading rates for phosphorus (g/m /yr) based on mean depth and mean hydraulic retention time of Mashkenode Lake: “Dangerous” (eutrophic rate) 0.84 “Permissible” (oligotrophic rate) 0.42 ------- 14 V. LITERATURE REVIEWED Anonymous, 1974. Wastewater disposal facilities inventory. MPCA, Minneapolis. Vollenweider, Richard A., (in press). Input-output models. Schweiz A. Hydrol. ------- 15 VII. APPENDICES APPENDIX A TRIBUTARY FLOW DATA ------- TRIBUTARY FLOW INFORMATION FOR MINNESOTA 10/30/74 LAKE CODE 2756 MASHKENODE LAKE TOTAL DRAINAGE AREA OF LAKE 17.60 SUB—DRAINAGE NORMALIZED FLOWS TRIBUTARY AREA JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MEAN 275661 17.60 0.61 0.65 2.12 45.40 22.20 11.60 9.20 2.95 3.42 6.11 4.02 1.07 9.11 275681 16.70 0.61 0.64 2.09 42.80 21.00 11.00 8.74 2.80 3.26 5.80 3.81 1.04 8.63 2756ZZ 0.90 0.02 0.01 0.07 1.93 1.02 0.61 0.42 0.11 0.18 0.21 0.14 0.04 0.40 SUMMARY TOTAL DRAINAGE AREA OF LAKE z 17.60 TOTAL FLOW IN = 108.35 SUM OF SUB—flRAINAGE AREAS 17.60 TOTAL FLOW OUT = 109.35 MEAN MONTHLY FLOWS AND DAILY FLOWS TRIBUTARY MONTH YEAR MEAN FLOW DAY FLOW DAY FLOW DAY FLOW 2756A1 10 72 3.81 15 3.80 11 72 2.01 12 2.60 12 72 0.70 1 73 0.49 9 0.50 2 73 0.66 3 73 4.54 9 0.90 4 73 9.99 18 8.90 5 73 16.90 2 11.00 19 8.10 6 73 8.24 7 4.60 7 73 4.05 A 73 5.66 19 12.60 25 4.50 9 73 2.01 23 1.40 275681 10 72 3.61 15 3.60 II 72 1.91 12 2.40 72 0.68 1 73 0.49 9 0.50 2 73 0.65 3 73 4.47 9 0.90 4 73 9.42 18 8.40 5 73 16.00 2 11.00 19 7.70 6 73 7.81 7 4 .4Q 7 73 3. S 8 73 5.38 19 8.60 25 4.30 9 73 1.92 23 1.30 27562 ? 10 7 0.15 IS 0.20 11 7? 0.07 12 0.09 1? 72 0.02 I 73 0.02 9 0.02 2 73 3 73 0.1S 9 0.03 4 73 0.42 1 0.40 S 73 0.7A 2 0.50 19 0.40 6 73 0.43 7 0.20 7 73 0.10 0 73 0.21 19 0.47 25 0.17 9 73 0.11 23 0.07 ------- APPENDIX B PHYSICAL and CHEMICAL DATA ------- STORET RETRIEVAL DATE 74/10/30 275601 47 49 42.0 092 35 52.0 MASHKENOOE LAKE 27 MINNESOTA 11EPALES 2111202 3 0015 FEET DEPTH 00010 00300 00077 00094 00400 00410 00630 00610 00665 00666 DATE TIME QE TH WATER DO TRANSP CND&JCTVY PH T * 1K N02&N03 NH3—N PHOS—TOT Pt$OS—DIS FROM OF TEMP SECCHI FIELD CACO3 N—TOTAL TOTAL TO DAY FEET CENT G/L INCHES MICROMHO SU MG/L MG/I MG/I MG/L P MG/I P 7?/07/1O 18 30 0000 46 270 9.30 102 0.110 0.080 0.074 0.023 18 30 0004 ‘2.0 11.2 300 9.20 99 0.090 0.070 0.076 0.022 - 18 30 0012 17.9 0.2 330 7.40 119 0.370 0.630 0.277 0.131 77/09/09 08 18 0000 15.6 42 305 8.80 108 0.070 0.080 0.092 0.028 08 18 0005 15.6 9.3 300 8.83 109 0.060 0.800 0.124 0.026 72/10/19 15 10 0000 36 300 8.70 87 0.040 1.075 0. OSI 0.0 16 15 10 0004 3.8 12.0 300 8.70 92 0.040 0.580 0.058 0.019 15 10 001 3.8 12.0 300 8.70 88 0.040 0.080 0.052 0.019 3721 7 DATE TIME DEPTH CHLPPHYL FROM OF A TO DAY FEET IJG/L 77/07/10 18 30 0000 ?4.3J 77/09/09 0$ 18 0000 13.7J 77/10/19 15 10 0000 37.9J J VALUE KNOWN TO E IN ERROR ------- APPENDIX C TRIBUTARY DATA ------- ST)°ET RETRIEVAL DA1T 74/10/30 ?756A1 LS27 56A1 47 29 30.0 092 36 00.0 UNNAMED Ti IH FROM LK TO TWO RIVE 27 7.5 EVELETrI O/M sHKENODF LAKE XING 3.5 M NW OF EVELETH IIEPALES 2111204 4 0000 FEET DEPTH 0 63C 33675 00610 00671 00665 DATE TIME 1) T’- NO2f NO3 TOT i JEL hJH3—r’! iOS—DIS PHOS—TOT FROM OF N—TOTAL N TOTAL UPTHO TO DAY FEET M(,/L MG/L MG/L MG/L P MG/L p 72/10/15 16 45 0.026 0.89? 0.081 0.007 0.070 72/11/17 10 15 0.042 0.840 ).087 0.0?? 0.075 71/04/1 lB “) 0.014 0.901’ 0.021 0.006 0.075 73/05/0? 18 3 ) 0.012 0.780 0.011 0.007 0.075 73/05/19 II 45 J. OI OK 0.560 0.009 0.010 0.070 73/06/07 14 45 0.011 0.96’) 0.060 0.050 0.057 73/0 4/19 14 35 .027 1.050 0.090 0.110 71/OM/?S L7 70 0.k60 0.036 0.029 0.050 71/09/23 11 45 0.500 I.G50 0.075 0.008 0.120 K VALUE. KNOWN TO E LESS THAN I ’JDICATED ------- STO ET PETI lEV4L DATE 7 e/1(J/3O 2756131 LS2756 1 47 30 30.0 092 34 30.0 UNNAMED TRIB TO LK FROM N SLOE 27 CO #69. SHEET #3 1/MASKENODE LAKE CO HWY 103 XING ABOV NICHOLS SIP 1 1EPALES 2111204 4 0000 FEET DEPTH 0063u 006?5 00610 00671 00665 DATE TIME DE°TH NO &NO3 TOT KJEL N-13—N PHOS—DIS PHOS—TOT FROM OF N—TOTAL N IOTAL ORTriO TO DAY FEET MG/L ‘AG/L Mr,fL MG/L P MG/L P 7?/10/IS 16 30 0.870 0.350 0.07? 0.005K O.0?0 7?/11/12 10 45 0.46( O.7 ) 0.130 0.005K 73/O4/J 19 10 O.?31 0. ’ R0 0.038 0.006 0.050 73/05/0? IR 15 fl.7 - ,? C.6Q0 0.026 0.00 5K 0.040 71/05/1 14 00 O.3 4O 0.480 0.035 0.008 0.015 73/06/07 14 35 0.800 0.6 ’.0 0.069 0.022 0.050 7 3 /O9/I 14 ‘+0 L.50i) 0. 70 0.034 0.011 0.025 73/OR/?c 17 10 1.2?0 0.175 0.04? 0.006 0.020 71/09/ 3 1? iS i.lh O O. 40 C.088 0.075 K VALUE KNO SN TO BE LESS THAN INDICATED ------- STORET RETRIEVAL DATE 74/10/30 275651 TF275651 P012450 47 31 30.0 092 34 30.0 VIRGINIA 27 7.5 VIRGINIA T/MASNKENODE UNNAMED STREAM IIEPALES 214)204 4 0000 FEET DEPTH 00630 00625 00610 00671 00665 50051 50053 DATE TIME DEPTH NO2 .NO3 TOT cJEL NH3-N PIIOS—DIS PHOS—TOT FLOW CONDUIT FROM OF N—TOTAL N TOTAL ORTHO RATE FLOW—M&0 TO DAY FEET HG/L MG/L MG/I HG/I P HG/L P INST M60 MONTHLY 73/01/31 11 00 CP(T)— 10.000 14.000 0.140 4.175 4.700 2.060 2.160 73/01/31 13 00 73/02/2R ii 00 CP(T)— M.7 00 8.R00 0.155 3.600 4.400 2.350 2.040 73/02/2M 13 00 73/03/11 11 00 CP(T)— 9.400 6.900 0.540 3.500 4.200 2.700 2.480 73/03/31 13 00 73/04/30 11 00 CP(T)— 9.700 9.200 0.041 3.100 4.000 3.000 2.350 73/04/30 13 00 73/05/29 11 00 CP(T)— 10.000 7.200 0.350 3.500 4.500 2.540 2.740 73/05/29 13 00 71/06/30 11 00 CP(T)— R.200 2.?00 0.650 2.200 3.300 2.560 2.370 73/06/30 13 00 73/07/31 11 00 CP(T)— 9.200 2.400 1.030 3.100 3.500 2.680 2.590 73/07/31 13 00 73/OR/3 1 10 00 CP(T)— 5.700 2.960 3.600 2.100 2.480 73/OR/31 1? 00 73/09/30 11 00 CP(T)— 7.800 .?O0 0.360 3.900 4.300 2.120 2.280 73/oq/30 13 00 73/10/31 I I 00 CP(T)— 9.700 6.500 0.090 3.330 4.400 2.120 2.670 73/10/31 13 00 73/11/30 II 00 CP(T)— M.400 6.150 0.190 4.400 6.250 2.370 2.300 73/11/30 13 00 74/01/01 11 00 CP(T)— 13.000 6.100 0.051 4.050 5.100 2.300 2.300 74/01/01 13 00 ------- STOPET ETPIEVAL P)ATF 74/10/30 275651 TF275651 P012450 47 31 30.0 092 34 30.0 VIRGINIA 27 7.5 VIRGINIA T/ ’1ASHKEr ’JODE UNNAMED STI €.AM 11E’ ALES 141204 4 0000 FEET DEPTH c ’30 O0’? (V)610 00671 00665 50051 50053 r)ATE [ PIE DF’ T -l NO 7 NO3 TOT PcJFL JH3—N Phos—DIS I-iOS—TOT FLOW CONDUIT FOOM (W rJ—tOTAL N TOTAL OPTkO RATE FLOW—MGO TO DAY FFET (‘/L MG/I MG/L MG/L P MG/L P INST MGD MONTHLY 74/01/31 11 00 CP(T)— 10.1G 4.cO O 0. lPfl 4.600 7.600 2.240 2.740 74/01/31 13 00 ------- |