s 333.91 M26prar 1992 1992 ANNUAL REPORT to the GOVERNMENTS OF CANADA, UNITED STATES, SASKATCHEWAN AND MONTANA iSTATE DOCUMENTS COLLECTION FEB 2 e 1994 MONTANA STATE LIBRARY 1515 E. 6th AVE. HELENA, MONTANA 59620 POPLAR RIVER BILATERAL MONITORING COMMITTEE CX)VERING CALENDAR YEAR 1992 Poplar December 1993 3 0864 1004 5765 7 1992 ANNUAL REPORT to the GOVERNMENTS OF CANADA, UNITED STATES, SASKATCHEWAN AND MONTANA by the POPLAR RIVER BILATERAL MONITORING COMMITTEE covering calendar year 1992 December 1 993 Poplar River Bilateral Monitoring Committee Department of State Washington, D.C., United States Governor's Office State of l\yiontana Helena, Montana, United States Department of External Affairs Ottawa, Ontario, Canada Saskatchewan Environment and Resource Management Regina, Saskatchewan, Canada Ladies and Gentlemen: During 1992, the Poplar River Bilateral Monitoring Committee continued to fulfill the responsibilities assigned by the governments under the Poplar River Cooperative Monitoring Agreement dated September 23, 1980. Through the exchange of Diplomatic Notes, on March 12, 1987, the Arrangement was extended to March 1991. In July 1992, another exchange of Diplomatic Notes extended the Arrangement retroactively from March 31, 1991 to March 31, 1996. In addition, the Arrangement was modified to terminate quarterly exchange of data and substitute an annual exchange of data. The enclosed report summarizes current conditions and compares them to guidelines for specific parameter values that were developed by the International Joint Commission under the 1977 Reference from Canada and the United States. After examination and evaluation of the monitoring information for 1992, the Committee finds that the measured conditions meet the recommended objectives. However, the Committee notes that flow-weighted concentration of total dissolved solids in streamflow in the East Poplar River at the International Boundary continues to increase and is approaching the long-term objective of 1 ,000 milligrams per liter During 1992, monitoring continued in accordance with Technical Monitoring Schedules outlined in the 1991 Annual Report of the Poplar River Bilateral Monitoring Committee. Herein is the 12th Annual Report of the Poplar River Bilateral Monitoring Committee. This report discusses the Committee activities of 1992 and presents the proposed monitoring schedule for 1993. Yours sincerely. .ft i\UJLJ Me A. Moreland fhairman. United States Section R.A. Halliday Chairman, Canadian Section /C '^■ '-f'-r Gary Fritz Member, United States Section D.D. Nargang Member, Canadian Section TABLE OF CONTENTS Highlights for 1992 iii 1.0 Introduction 1 2.0 Committee Activities 2 2.1 Membership 2 2.2 l\/leetings 2 2.3 Review of Water-Quality Objectives 3 2.4 Data Exchange 5 3.0 Water and Air: Monitoring and Interpretations 5 3.1 Poplar River Power Station Operation 5 3.2 East Poplar River 5 3.2.1 Streamflow 5 3.2.2 Apportionment 6 3.2.3 Minimum Flows 7 3.2.4 On-Demand Release 8 3.2.5 Water Quality 8 3.2.5.1 Total Dissolved Solids 8 3.2.5.2 Boron 11 3.2.5.3 Other Water-Quality Variables 13 3.3 Groundwater 15 3.3.1 Operations 15 3.3.2 Ground-Water Levels 15 3.3.2.1 Saskatchewan 15 3.3.2.2 Montana 17 3.3.3 Ground-Water Quality 19 3.3.3.1 Saskatchewan 19 3.3.3.2 Montana 25 3.4 Cookson Reservoir 26 3.4.1 Storage 26 3.4.2 Water Quality 27 3.5 Air Quality 28 3.5.1 Saskatchewan Environment and Resource Management 28 3.5.2 SaskPower Corporation 28 3.6 Quality Control 29 3.6.1 Streamflow 29 3.6.2 Water Quality 29 4.0 References Cited 31 ANNEXES 1 .0 Poplar River Cooperative Monitoring Arrangement, Canada-United States A1 -1 2.0 Poplar River Cooperative Monitoring Arrangement, Technical Monitoring Schedules, 1993, Canada-United States A2-1 3.0 Recommended Flow Apportionment in the Poplar River Basin A3-1 4.0 Metric Conversions A4-1 TABLES Table 2.1 Recommended Water-Quality Objectives 4 Table 3.1 Recommended Water-Quality Objectives and Excursions, 1992 Sampling Program, East Poplar River at International Boundary 14 Table 3.2 Water-Quality Statistics for Water Pumped from Supplementary Water Supply Project Wells Sampled at Site "C3" on Girard Creek 20 Table 3.3 Water-Quality Statistics for Water Pumped from Soil Salinity Project Wells Sampled at the Discharge Pipe 21 Table 3.4 Cookson Resen/oir Storage Statistics for 1992 26 Table 3.5 Streamflow Measurement Results for June 17, 1992 29 FIGURES Figure 3.1 Discharge during 1992 as Compared with the Median Discharge for 1961-1990 for the Poplar River at the International Boundary 6 Figure 3.2 Flow Hydrograph of the East Poplar River at the International Boundary 7 Figure 3.3 TDS Concentrations for 1992 Grab Samples from East Poplar River at International Boundary 9 Figure 3.4 Three-Month Moving, Flow-Weighted TDS Concentration for East Poplar River at International Boundary 9 Figure 3.5 Five-Year Moving, Flow-Weighted TDS Concentration for East Poplar River at International Boundary 10 Figure 3.6 Boron Concentrations for 1 992 Grab Samples from East Poplar River at International Boundary 11 Figure 3.7 Three-Month Moving, Flow-Weighted Boron Concentration for East Poplar River at International Boundary 12 Figure 3.8 Five-Year Moving, Flow-Weighted Boron Concentration for East Poplar River at International Boundary 12 Figure 3.9 Drawdown for Hart Seam Aquifer as of December 1992 16 Figure 3.10 Cone of Depression in the Empress Sands Due to the Salinity Project as of December 1992 18 Figure 3.11 Hydrographs of Selected Wells 19 Figure 3.12 Total Dissolved Solids in Samples from Montana Monitoring Wells 25 Figure 3.13 Cookson Reservoir Mean Daily Water Levels for 1992 and Median Monthly Water Levels for 1981 -1991 27 HIGHLIGHTS FOR 1992 The Poplar River Power Station completed its ninth full year of operation in 1 992. The two 300- megawatt coal-fired units generated 4 692 000 gross megawatt-hours (MW/h) of electricity, 103 percent from 1991 and 102 percent from 1990. In 1992, the average capacity factor for Unit No. 1 was 92.8 percent and the average capacity factor for Unit No. 2 was 88.2 percent. Monitoring information collected in both Canada and the United States during 1992 was exchanged in the spring of 1993. In general, the sampling locations, frequency of collection, and parameters met the requirements identified in the 1992 Technical Monitoring Schedules set forth in the 1991 annual report. Regional drought conditions persisted during 1992 resulting in below nonnal streamflows. The March to October recorded flow of the Poplar River at the International Boundary for 1992 was 2 080 cubic decametres (dam^) which was 21 percent of the 1931 to 1991 median seasonal flow. The 1992 recorded flow volume of the East Poplar River at the International Boundary was 1 860 dam^. This volume Is 54 percent of the median annual flow since completion of Morrison Dam in 1975. The on-demand release, in accordance with the apportionment recommendations of the International Joint Commission (IJC), entitled Montana to 370 dam'^ for 1991-92 to be delivered between May 1 and May 30, 1 992. A volume of 480 dam^ was delivered during this period. iii 1.0 INTRODUCTION The Poplar River Bilateral Monitoring Committee was authorized for an initial period of five years by the Govemments of Canada and the United States under the Poplar River Cooperative Monitoring Arrangement dated September 23, 1980. A copy of the Arrangement is attached to this report as Annex 1 . On March 12, 1 987, the Arrangement was extended by the Govemments for four years to March 1991 . In July 1992, the Arrangement was further extended retroactively from March 31 , 1 991 to March 31, 1996 following a request from the Committee in 1991. A more detailed account of the historical background of the Arrangement is contained in the 1990 Annual Report of the Poplar River Bilateral Monitoring Committee. The Committee oversees monitoring programs designed to evaluate the potential transboundary impacts from SaskPower's (formeriy Saskatchewan Power Corporation) coal-fired themnal generating station and ancillary operations near Coronach, Saskatchewan. Monitoring is conducted in Canada and the United States at or near the International Boundary for quantity and quality of surface and ground water and for air quality. Participants from both countries, including Federal, State and Provincial agencies, are involved in monitoring. The Committee submits an annual report to Governments which summarizes the monitoring results, evaluates apparent trends, and compares data to objectives or standards recommended by the international Joint Commission to Govemments, or to relevant Federal, State or Provincial standards. The Committee reports to Govemments on a calendar year basis. This report is the twelfth in the series. The Committee is also responsible for drawing Government's attention to definitive changes in monitoring parameters which may require immediate attention. A responsibility of the Committee is review of the adequacy of monitoring programs in both countries and recommending changes in Technical Monitoring Schedules to Govemments. The Schedules are updated annually to document changes in monitoring locations, sampling frequencies, parameter lists, and analytical techniques. The Technical Monitoring Schedules listed in the annual 2 report (Annex 2) are given for the forthcoming year. The Committee reviews and proposes changes to the Technical i\/Ionitoring Schedules as information requirements change. 2.0 COMMITTEE ACTIVITIES 2.1 Membership The Committee is composed of representatives of the Federal Governments of the United States and Canada, the State Government of Montana, and the Provincial Government of Saskatchewan. In addition to the representatives of Govemments, two ex-officio members serve as local representatives for the State of Montana and the Province of Saskatchewan. ' During 1992, members of the Committee included: Mr J.R. Knapton, U.S. Geological Survey, United States representative and CoChairperson; Mr R.A. Halliday, Environment Canada, Canadian representative and CoChairperson; Mr A. Wittich, Govemor's Office, Montana representative; Mr D.D. Nargang, Saskatchewan Environment and Resource Management, Saskatchewan representative; Mr C.W. Tande, Daniels County Commissioner, Montana local ex- officio representative; and Mr J.R. Totton, Reeve, R.M. of Hart Butte, Saskatchewan local ex-officio representative. 2.2 Meetings The Committee met on June 2 and 3, 1 992, in Coronach, Saskatchewan. Delegated representatives of Govemments except the representative from the State of Montana attended the meeting. Neither of the ex-officio members were in attendance. In addition to Committee members, several technical advisors representing Federal, State and Provincial agencies participated in the meeting. During the meeting, the Committee reviewed the operational status of the power plant and mine; examined data collected in 1991 including surface-water quality and quantity, ground-water quality and quantity, and air quality; established the Technical Monitoring Schedules for 1992; considered a draft report on 3 quality-assurance results; discussed proposed changes in water-quality objectives; and toured the power plant, ash lagoons, mine, and other ancillary facilities. The Committee also prepared the first draft of the 1991 Annual Report to Govemments. 2.3 Review of Water-Quality Objectives The International Joint Commission in its Report to Govemments, titled "Water Quality in the Poplar River Basin," recommended that the Committee "periodically review the water-quality objectives within the overall Basin context and recommend new and revised objectives as appropriate." In 1 991 , the Committee undertook a review of water-quality objectives. A subcommittee composed of Mr. J.R. Knapton, U.S. Geological Survey; Mr J.-G. Zakrevsky, Environment Canada; Mr A. Horpestad, Montana Department of Health and Environmental Sciences; and Mr D.D. Nargang, Saskatchewan Environment and Resource Management, was formed to review and recommend changes in water-quality objectives. The subcommittee examined the entire data base collected during the last eleven years of monitoring. This data base has led to a better understanding of background conditions in the basin and documented the presence or absence of trends in monitored constituents. The subcommittee agreed that dissolved trace elements should be dropped from the water-quality objectives. The group reached consensus that total trace element concentrations provided more meaningful information but that differences in laboratory analytical procedures and field techniques would have to be investigated to determine comparability of data. The subcommittee noted that mercury concentrations in tissue from fish in Cookson Reservoir are less than Canadian consumption guidelines. However, the subcommittee recommended that fishery experts be consulted before a decision is made to drop the objective. The subcommittee also reviewed the water-quality objectives for 5-year and 3-month flow-weighted concentrations for total dissolved solids and boron. Although the subcommittee agreed that calculation procedures to determine flow-weighted concentrations are time consuming and probably scientifically questionable, no consensus was reached on alternative objectives or procedures. Recommendations of the subcommittee are summarized in Table 2.1 . Table 2. 1 Recommended Water-Quality Objectives. PARAMETER PRESENT OBJECTIVE RECOMMENDATION NEW OBJECTIVE Boron, total ^3.5/2.5 Discontinue flow weighting ? TDS M 500/1000 Discontinue flow weighting ? Aluminum, dissolved 0.1 Discontinue Ammonia, un-ionized 0.02 Base objective on temperature and pH (table to be done later) Cadmium, total 0.0012 Continue as is 0.0012 Chromium, total 0.05 Discontinue -- Copper, dissolved 0.005 Discontinue - Copper, total 1.0 Continue as is 1.0 Fluoride, dissolved 1.5 Continue as is 1.5 Lead, total 0.03 Continue as is 0.03 Mercury, dissolved 0.0002 Change to total 0.0002 Mercury, fish (mg/kg) 0.5 Discuss with fisheries people ? Nitrate 10 Continue as is 10 Oxygen, dissolved 24.0/5.0 Objective applies only during open water 24.0/5.0 SAR (units) 10.0 Continue as is 10.0 Sulfate, dissolved 800 Continue as is 800 Zinc, total 0.03 Continue as is 0.03 Water temperature (C) ^30.0 Continue as is ^30.0 pH (units) ^6.5 Continue as is (need to detennine what is natural) "6.5 Coliform (no./100 mL) Fecal 2,000 Discontinue -- Total 20,000 Discontinue -- Units In mg/L except as noted. 1. Five-year average of flow-weighted concentrations (March to October) should be <2.5 boron, <1000 TDS. Three-month average of flow-weighted concentration should be <3.5 boron and <15(X) TDS. 2. 5.0 (minimum April 10 to May 15), 4.0 (minimum remainder of year). 3. Natural temperature (April 10 to May 15), <30 degrees Celsius (remainder of year). 4. Less than 0.5 pH units above natural, minimum pH = 6.5. 2.4 Data Exchange The Committee is responsible for assuring exchange of data between governments. The exchange of monitoring information was initiated in the first quarter of 1981 and was an expansion of the informal quarterly exchange program initiated between the United States and Canada in 1976. Until 1991 , data were exchanged on a quarterly basis. At the request of the Committee, the United States and Canada agreed to replace the quarterly exchange of data with an annual exchange effective at the beginning of the 1 992 calendar year Henceforth, data will be exchanged once each year as soon after the end of the calendar year as possible. However, unusual conditions or anomalous information will be reported and exchanged whenever warranted. No unusual conditions occurred during 1992 which would warrant special reporting. 3.0 WATER AND AIR: MONITORING AND INTERPRETATIONS 3.1 Poplar River Power Station Operation In 1992, the average capacity factor for Unit No. 1 was 92.8 percent. The average capacity factor for Unit No. 2 was 88.2 percent. The capacity factors are based on the maximum power generation rating of 297.8 MW/h for Unit No. 1 and 294 MW/h for Unit No. 2. Total power generated from both units was 4 692 000 gross megawatt-hours which is about 103 percent of 1991 power and 102 percent of 1 990 power 3.2 East Poplar River 3.2.1 Streamflow Streamflow in the Poplar River basin was below normal in 1992. The f^arch to October recorded flow of the Poplar River at the international Boundary, an indicator of natural flow in the basin, was 2 080 cubic decametres which was 21 percent of the 1931 to 1991 median seasonal flow. For the 6 sixth consecutive year, the flow was below normal. A comparison of 1992 monthly mean discharge with the 1961-90 median discharge is shown in Figure 3.1. o o LxJ (/) a: Ld CL C/O UJ en 1.000 0.800 0.600 o m o z (jj o < X o Q 0.400 0.200 0.000 MEDIAN OF MONTHLY MEAN DISCHARGE FOR 1961 -1990 J MONTHLY MEAN DISCHARGE FOR 1 992 :^^ MAR APR MAY JUN JUL AUG SEP OCT Figure 3.1 Discharge during 1992 as Compared with the IVIedian Discharge from 1961-1990 for the Poplar River at the International Boundary. The 1992 recorded flow volume of the East Poplar River at the International Boundary was 1 860 dam-^. This volume is 54 percent of the median annual flow since the completion of Morrison Dam in 1975. 3.2.2 Apportionment In 1976 the International Souris-Red Rivers Engineering Board, through its Poplar River Task Force, completed an investigation and made a recommendation to the governments of Canada and the United States regarding the apportionment of waters of the Poplar River basin. Although not officially adopted by the two countries, the Poplar River Bilateral Monitoring Committee has adhered to the Apportionment Recommendations in each of its annual reports. Annex 3 contains the apportionment recommendation. 3.2.3 Minimum Flows The recorded volume of the Poplar River at the International Boundary from March 1 to May 31, 1992 was 1 460 dam-^. Based on IJC recommendations and the assumption that the recorded flow is the natural flow, the United States was entitled to a minimum discharge on the East Poplar River of 0.028 cubic metres per second (m^/s) for the period June 1, 1992 to May 31, 1993. The minimum flow for the period January 1 to May 31, 1992 had previously been determined on the basis of the Poplar River flow volume for March 1 to May 31 , 1 991 . A hydrograph for the East Poplar River at the International Boundary and the minimum flow as recommended by the IJC are shown in Figure 3.2. Daily flows during 1992 were above the recommended minimum at all times with the exception of December 29, 30, 31, 1992. Extremely cold temperatures reduced the flow to 0.027 m^/s on these days. T 1 1 1 1 1 1 r / 0.028 m3/t Apportionment recommendation for minimum flow JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 1992 Figure 3.2 Flow Hydrograph of the East Poplar River at the International Boundary. 3.2.4 On-Demand Release In addition to the minimum flow, the IJC apportionment recommendation entitles Montana to an on- demand release to be delivered during the twelve month period commencing June 1, 1991. Based on the runoff volume recorded at the Poplar River at the Intemational Boundary gaging station during the March 1 to May 31, 1991 period, Montana was entitled to a release of 370 dam"' from Cookson Reservoir Montana requested this release to be made between May 1 and May 30, 1992. A volume of 480 dam^ was delivered during this period. 3.2.5 Water Quality The 1981 report by the IJC to Governments recommended: For the March to October period, the maximum flow-weighted concentrations should not exceed 3.5 milligrams per liter (mg/L) for boron and 1 500 mg/L for total dissolved solids for any three consecutive months in the East Poplar River at the International Boundary. For the March to October period, the long-term average of flow-weighted concentrations should be 2.5 mg/L or less for boron, and 1 000 mg/L or less for total dissolved solids in the East Poplar River at the International Boundary. The Bilateral Monitoring Committee adopted the approach that, for the purposes of comparison with the proposed IJC long-term objectives, the boron and total dissolved solids (TDS) data are best graphically plotted as 5-year moving flow-weighted concentrations (FWCs) which were advanced one month at a time. 3.2.5.1 Total Dissolved Solids TDS data for grab samples collected by Environment Canada and the U.S. Geological Survey in 1992 are shown in Figure 3.3. TDS ranged from 743 mg/L (March 16) to 1 286 mg/L (May 19). The short-term objective for TDS is 1 500 mg/L. A time plot of the 3-month moving FWCs for TDS is presented in Figure 3.4. No exceedances of the objective have been observed during any 3-month period since 1975. The 3-month FWCs remained confined within a narrow range centered around a mean of approximately 1 000 mg/L during 1992. 1300 1200 1100 3 1000 m Q H 900 800 - 700 - • • - 1992 N 1993 Figure 3.3 TDS Concentrations for 1992 Grab Samples from East Poplar River at International Boundary. 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 I ' I '—1 ' I ' I ' 1 ' I ' I ' 1 ' I ' I ' I ' I ' I ' r Short-Term Objective (1500 mg/L) from sample analysis, from regression _l I I I I ■ I 1974 1975 1978 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 Year Figure 3.4 Three-Month Moving, Flow-Weighted TDS Concentration for East Poplar River at International Boundary. 10 Five-year FWCs for TDS (Figure 3.5) remained below the long-term objective of 1 000 mg/L. An increase in the 5-year FWCs to approximately 955 mg/L was observed in 1992. A 200-mg/L increase had previously occurred in early 1988 and had been maintained through 1989 and 1990. The 1991 rise in FWCs corresponds to depressed spring flows in the East Poplar River A similar increase in TDS was seen during mid-1987. Relatively low spring discharges have occurred since 1 984. If this trend continues, it is expected that FWCs will reach the 1 000 mg/L objective. The TDS increase can be explained in part by salt build-up in Cookson Reservoir as a result of water being used for cooling. Forced evaporation causes salts to concentrate within the reservoir This process is further driven by drought conditions which prevailed over the last half of the data record (Lang and Jones, 1988). In addition, low-flow conditions (when flows are derived largely from ground-water sources) likely increase TDS concentrations and yields a positive TDS trend in the data. 1300 1200 1100 lOUO :j 900 6 800 700 m Q 600 500 400 300 200 100 "I — ' — I — ' — I — ' — I — ' — r -1 — I — I- Long-Term Objective (1000 mg/L) J . I I I I L J I I ^ \ I L 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 Year Figure 3.5 Five- Year Moving, Flow-Weighted TDS Concentration for East Poplar River at International Boundary. The relation between TDS and specific conductance generated from data collected from 1 975 to 1 992 is as follows: TDS = (0.632 X specific conductance) -f 1 9.97 (r2 = 0.86, n = 449) 11 3.2.5.2 Boron During 1992, boron concentrations in the East Poplar River at the international Boundary varied from 1.40 mg/L (March 16) to 2.34 mg/L (May 19) (Figure 3.6). 2.4 T5 C C5 2445- Jan-79 Jan-81 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Figure 3.11 Hydrographs of Selected Wells. 3.3.3 Ground-Water Quality 3.3.3.1 Sasi(atchewan The water quality from the Supplementary Water Supply Project discharge points has been consistent with no trends indicated. A summary of the more frequently tested parameters during 1992 is provided in Table 3.2. Statistical averages of the results since January 1990 are included in this table. 20 Table 3.2 Water-Quality Statistics for Water Pumped from Supplementary Water Supply Project Wells Sampled at Site "C3" on Girard Creek. 1990-1991 Average 1992 Average pH (units) 7.7 7.8 Conductivity (nS/cm) 1,383 1,381 Total dissolved solids 905 930 Total suspended solids 3.7 2.6 Boron 1.25 1.29 Sodium 178 180 Cyanide (ng/L) <2 <2 Iron 1.2 1.4 Manganese 0.24 0.23 Mercury (|xg/L) <0.10 <0.1 Units in mg/L except as noted. Girard Creek location "C3" is directly downstream from the majority of the pumped wells and provides a good indication of water quality entering Cookson Reservoir. Water quality at "C3" is better than current reservoir quality and therefore this water has a positive influence on the quality of water in the reservoir. The water quality of the common discharge point from the Soil Salinity Project wells is generally better than the water quality In Cookson Reservoir. Average results from the common discharge point for 1992, plus a summary of the 1990 and 1991 results, are provided in Table 3.3. Results have been consistent since 1 990. 21 Table 3.3 Water-Quality Statistics for Water Pumped from Soil Salinity Project Wells Sampled at the Discharge Pipe. 1990-1991 Average 1992 Average pH (units) 7.7 7.8 Conductivity (^S/cm) 1,457 1,388 Total dissolved solids 966 941 Boron 1.5 1.7 Calcium 111 98 Magnesium 60 58 Sodium 147 151 Potassium 7.4 7.6 Arsenic (ng/L) 13.1 15.3 Aluminum 0.011 0.012 Barium 0.025 0.028 Cadmium <0.001 <0.001 Iron 3.8 4.2 Manganese 0.31 0.15 Molybdenum 0.003 0.003 Strontium 1.70 1.86 Vanadium 0.003 0.002 Uranium (^g/L) <0.1 <0.1 Mercury (|ig/L) <0.10 <0.1 Sulfate 328 315 Units in mg/L except as noted. Ground-water quality can potentially be affected by seepage of the contaminants in the ash lagoons through the containment system. The piezometers listed in the Technical Monitoring Schedules are 22 used to detect leachate movement and calculate seepage rates. In 1992, 15 new piezometers were installed to obtain additional information on leachate effects and seepage from the ash lagoons. The piezometric surface for the oxidized strata shows a ground-water mound that has developed beneath the ash lagoons. The ground-water mound extends from the east side of Ash Lagoon No. 2, where a 6-metre increase has been noted, to the west side of the Polishing Pond, where levels have increased about 4 metres. The new oxidized-till piezometers installed along Dyke B confirm the ground-water mound that has developed. The oxidized-till piezometers closer to the reservoir have shown a decreasing trend in piezometric levels reacting to lower reservoir water levels. The largest changes in chloride and boron concentrations have occurred where the water levels have changed the most. This would be expected because changing water levels suggest leachate movement. Increasing boron concentrations on the east and south sides of Ash Lagoon No. 2, together with decreasing chloride concentrations, suggests leachate influence. On the west side of the Polishing Pond, boron concentrations have not changed significantly. Little change in boron or chloride concentrations has been noticed in samples from most of the oxidized-till piezometers located by the reservoir The only significant change in samples from any of these piezometers has been at C719 where chloride concentrations have decreased by 96 mg/L since 1983, to a concentration of 14.7 mg/L in 1992. This piezometer is beside the reservoir and the change in quality is due to the lower water levels of the reservoir rather than ash-lagoon influence. During the 1991 review, a ground-water mound was concluded to have developed in the unoxidized till similar to that in the oxidized till, extending from the east side of Ash Lagoon No. 2 to the west side of the Polishing Pond. The ground-water mound was known not to be continuous because some unoxidized-till piezometers within the mound area had no increase in piezometric level. The new piezometers installed along Dyke B (C868C, C869C, and C871C) provided some valuable infonnation. These piezometers located in the middle of the lagoon area are illustrating a 23 decreasing trend in piezometric levels matching decreasing reservoir levels. This new infonnation would suggest that the ground-water mound in the unoxidized till is not general but likely occurs in unconnected pockets. A review of boron and chloride concentrations does not show any strong trends. The piezometric surface of the Empress gravels indicate a regional flow from northwest to southeast below Morrison Dam. Since 1983, the closer an Empress piezometer is to the reservoir, the larger the decrease in water level. Around the lagoon area there is a noticeable drop in piezometric level at the north end of Ash Lagoons No. 1 and No. 2, and a mound has developed at the east end of Ash Lagoon No. 3 North. The mound on the east side of Ash Lagoon No. 3 North is likely due to upper horizon influences. Results for the Empress gravel do not indicate any seepage activity with the majority of piezometer wells showing little change in boron or chloride concentrations. Piezometer series C775 is located at the southeast corner of Ash Lagoon No. 3 North. Until 1992, chloride concentrations have only varied in samples from the oxidized-till piezometer C775A. For the last two years, water levels in the oxidized-till piezometer C775B, the unoxidized-till piezometer C775C, and the Empress-gravel piezometer C775D have increased. This is especially significant in C775B where the level has increased 6 metres in the last year and boron concentration has increased to 6.6 mg/L in 1992. The changes seen for the piezometers in the area are significant but more data will be needed to reach any firm conclusions. Sand-lense piezometers C712B, C766, and C767 are located between the Polishing Pond and the cooling water canal. C767 is located on top of Dyke G. C766 and C712B are located at the top of Dyke G. A review of the boron concentrations for samples from C766 shows an increasing trend until October 1988 when levels peaked at 12.6 mg/L. Boron concentration decreased to 6.99 mg/L in April 1990, 24 started increasing again, and peaked at 23.7 mg/L at the end of 1991. In 1992, the boron concentrations remained stable at about 25 mg/L. Until April 1988, the boron concentration for samples from C767 was increasing and peaked at 49.4 mg/L. From this peak, the boron concentration has steadily decreased. By the end of 1991 the boron concentration had leveled off t>elow 4 mg/L and remained at this concentration through 1992. The reduction in boron concentrations for samples from C767 to background concentrations suggest a leachate plume and not a continuous front. Piezometer C712B has been monitored for several years. Historically, boron concentrations have been below 1 mg/L. In mid-1987, increasing boron concentrations were noted with the concentration peaking in April 1992 at 26.6 mg/L. Chloride concentrations trended down in samples from C712B to 50 mg/L in 1988 from over 200 mg/L in 1984. Since 1988, chloride concentrations have changed little with the exception of a spike over 125 mg/L in 1991 . There is an increasing trend in samples from piezometer C767, increasing from about 25 mg/L in 1989 to 75 mg/L in 1991. Since 1991, the chloride concentrations in samples from C767 have remained about 75 mg/L. The chloride concentrations for samples from C766 have shown little change since 1987 and remain between 20 and 30 mg/L, similar to ash-lagoon chloride concentrations. The lag time for the boron concentration to increase when compared to chloride is expected because boron moves slower through soil than an element like chloride. The higher boron concentrations in samples from C767 than in samples from the other two piezometers are much closer to the boron concentrations in the Polishing Pond. The total calculated seepage from the ash lagoon was determined to be 1.51 Us. This is an increase over the 1991 calculated value of 1.267 Us. The increase can mostly be attributed to the increase in calculated seepage rates for Ash Lagoon No. 1 from 0.245 L/s in 1991 to 0.417 L/s in 1992. The piezometric levels in the new piezometers 25 installed on the west side of Ash Lagoon No. 1 closely matched levels in other piezometers on the west side of the ash lagoons and these levels did not affect calculations. However, the new piezometers on the east side of Ash Lagoon No. 1 did indicate large increases in piezometric levels from background values and when these levels were added to the calculation, the calculated seepage rates increased. The piezometers on the east side of Ash Lagoon No. 1 provided data in an area where there was no previous information. Calculated liner permeabilities for the ash lagoons have remained about 1 0"^ cm/sec. The calculated total seepage from the ash lagoons is well below the seepage limits proposed in 1 979 by the International Poplar River Water Quality Board of the International Joint Commission. 3.3.3.2 Montana Samples for water-quality analysis were collected from Montana monitoring wells 5-11, 15, 16, 19, 23, and 24 in 1992. Graphs of total dissolved solids for selected wells are shown in Figure 3.12. 200 Jan-79 Jan-81 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Date Figure 3.12 Total Dissolved Solids in Samples from Montana Monitoring Wells. 26 3.4 Cookson Reservoir 3.4.1 Storage On January 1, 1992, Cookson Reservoir storage was 23 500 dam'^--54 percent of the full-supply volume. During the year, precipitation was below normal resulting in below normal inflows. The 1992 maximum, minimum, and period elevations and volumes are shown in Table 3.4. In addition to runoff, reservoir levels were augmented by ground-water pumpage. Wells in the abandoned west block mine site supplied 5 225 dam"^ to Girard Creek. Approximately 70 percent of this flow volume reached Cookson Reservoir. Wells in the Soil Salinity Project supplied 942 dam^^ directly to the reservoir. Table 3.4 Cookson Reservoir Storage Statistics for 1 992. Date Elevation (m) Contents (dam^) January 1 749.944 23 500 March 3 (maximum) 749.989 23 800 October 14 (minimum) 749.085 19 500 December 31 749.116 19 800 Full-supply level 753.000 43 400 The Poplar River Power Station is dependent on water from Cookson Reservoir for cooling. Power plant operation is adversely affected when reservoir levels drop below 749.0 metres. The dead- storage level for cooling water used in the generation process is 745.0 metres. The 1 992 recorded levels and associated operating levels are shown in Figure 3.13. As indicated in Figure 3.13, 1992 reservoir levels were well below the ten-year median levels. 27 _j 756 ^ 755 LlJ _l 754 ^ 753 > 751 ^ 750 in 749 ^ 748 ^ 747 Z 746 2 745 O 744 ^ 743 y 742 ^ 741 T 1 1 1 1 1 1 1 1 I f Full Supply Level missing data \ 'Minimum Desired Operating Level 'Unusable Storage Level MEAN DAILY WATER LEVEL FOR 1 992 MEDIAN OF MONTHLY MEAN ELEVATION FOR 1 981 -1 991 56500 CO 51900 LjJ cc 43400 1- LU 35900 :^ < 29400 u UJ 23800 CJ o 19100 CD 14900 :d u 11400 z 8340 (/i 5860 1- 7' h 1 3780 1— -F 2000 O r 1 550 0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 1992 Figure 3.13 Cookson Reservoir Mean Daily Water Levels for 1992 and Median Monthly Water Levels for 1981-1991. 3.4.2 Water Quality For the last several years, the lack of normal spring runoff has been the most significant factor influencing Cookson Reservoir water quality. During 1992, Cookson Reservoir did not experience boron concentrations in excess of 3.5 mg/L However, the reservoir water quality exceeded 1 500 mg/L for total dissolved solids. The net effect of little spring runoff over the last several years has been a decrease in reservoir water quality. From 1988 to the end of 1992, several analytes have doubled in concentration; sulfate, sodium, and boron, for example. The reservoir water quality has decreased to the point that a substantial spring mnoff will be required to have any significant impact on the reservoir quality. 28 3.5 Air Quality 3.5.1 Saskatchewan Environment and Resource Management Ambient sulphur dioxide (SO2) monitoring was discontinued on March 30, 1 992. During the 3-month period of 1992, ambient sulphur dioxide monitoring recorded no violations of Saskatchewan Environment and Resource Management's hourly and 24-hour average standards of 0.17 and 0.06 parts per million (ppm), respectively. The highest recorded hourly value of 0.082 ppm SO2 was recorded on March 27th at 13:00 hours, as compared to 0.137 ppm SO2 recorded in September 1 991 . The highest 24-hour average reading of 0.011 ppm occurred on March 27th as compared with 1991's highest average reading of 0.11 ppm. There was no downtime for the monitor during the 3- month period. The High-Volume Sampler was also discontinued on March 30, 1992. Suspended particulate concentrations obtained from the monitor at the same site for the 3-month period did not exceed Saskatchewan Environment and Resource Management's 24-hour average standard of 120 micrograms per cubic metre (ng/m^) per 24 hours as compared to the two occasions in 1991 in September and October at 162.2 ^ig/m^, and 197.7 ^ig/m^ respectively. The annual geometric mean was not calculated for 1992 and there was no downtime for the 3-month period as compared to 3.3 percent downtime for 1991 . 3.5.2 SaskPower Corporation SaskPower Corporation's (SPC) ambient SO2 monitoring for 1992 recorded no violations of Saskatchewan Environment and Resource Management's hourly and 24-hour average standards. The highest recorded hourly value of 0.067 ppm SO2 was recorded on October 9, 1992 at 11:00 hours. 29 Total suspended particulate concentrations for 1992 obtained from SPC's monitor exceeded Saskatchewan's 24-hour standard of 120 ng/m^on three separate occasions: April 12th (246.4 M-g/m^), April 30th (318.6 ^ig/m^), and May 8 (363.6 \ig/m^). In all cases, the prevailing wind direction eliminated the power station as a possible influence. The geometric mean for the high-volume air sampler for 1 992 was 23.8 ^ig/m^. 3.6 Quality Control 3.6.1 Streamflow To test the quality of streamflow calculations made by the U.S. Geological Survey (USGS) and Environment Canada (EC), similar measurements were made on the East Poplar River at the International Boundary on June 17, 1992 by personnel from both agencies. The discharges shown in Table 3.5 agree within measurement error Table 3.5 Streamflow Measurement Results for June 17, 1992. Agency Time CST Width (m) Mean Area (m2) Velocity (m/s) Gauge Height (m) Discharge (m^/s) EC 09:00 1.4 0.143 0.369 1.527 0.053 USGS 08:30 1.4 0.131 0.369 1.524 0.048 3.6.2 Water Quality Quality-control sampling was carried out at the East Poplar River at the Intemational Boundary on July 15, 1992. Participating agencies included in the U.S. Geological Survey Environment Canada, Saskatchewan Environment and Resource Management, and SaskPower Corporation. 30 Sets of triplicate samples were split from U.S. Geological Survey sampling chums and submitted to tfie respective agency laboratories for analyses. Field procedures were identical to those used since 1986. Most parameters showed acceptable reproducibility within and between sets of triplicates. Only the variables for which corrective action should be considered are discussed here. Field temperature results showed an unacceptable level of inter-agency variability with values ranging from 16.5 °C to 18.0 °C. Dissoived-oxygen concentrations ranged from 10.0 to 11.2 mg/L Between-triplicate results were not comparable for ortho phosphorus, total ammonia, chloride, total barium, total vanadium, and dissolved iron. For TDS, dissolved iron, dissolved boron, silica, total chromium and color, one set of results was noticeably high compared to the other reported sets. Similariy one of the reported triplicate data sets was low for lab pH. Since most of the metals were present in the samples at concentrations near or below analytical detection limits, a satisfactory evaluation of data comparability for these constituents is not possible. 31 4.0 REFERENCES CITED Integrated Environments Limited, 1991 , The use of the TYDAC SPANS GIS in the assessment and review of pesticide residues detected in surface waters of the Prairie Provinces and the Northwest Territories. (Prepared for Environment Canada, Inland Waters Directorate, Western and Northern Region, Water Quality Branch, Regina, Saskatchewan.) 138 p. Lang, T.-A., and Jones, K., 1988, A comparison of the meteorological conditions during the droughts of the 1930's and the 1980's for the Prairie Provinces. Environment Canada, Atmospheric Environment Service, Regina. Report No. CSS-R89-01 (A publication of the Canadian Climate Program.) 50 p. ANNEX 1 POPLAR RIVER COOPERATIVE MONITORING ARRANGEMENT CANADA-UNITED STATES A1-1 September 23, 1980 POPLAR RIVER COOPERATIVE MONITORING ARRANGEMENT I. PURPOSE This Arrangement will provide for the exchange of data collected as described in the attached Technical Monitoring Schedules in water quality, water quantity and air quality monitoring programs being conducted in Canada and the United States at or near the International Boundary in response to SaskPower development. This Arrangement will also provide for the dissemination of the data in each country and will assure its comparability and assist in its technical interpretation. The Arrangement will replace and expand upon the quarterly information exchange program instituted between Canada and the United States in 1976. II. PARTICIPATING GOVERNMENTS Governments and government agencies participating in the Arrangement are: Government of Canada: Environment Canada Government of the Province of Saskatchewan: Saskatchewan Environment and Public Safety (now Saskatchewan Environment and Resource Management) Government of the United States of America: U.S Geological Survey Government of the State of Montana: Executive Office III. POPLAR RIVER MONITORING COMMITTEE: TERMS OF REFERENCE A binational committee called the Poplar River Bilateral Monitoring Committee will be established to carry out responsibilities assigned to it under this Arrangement. The Committee will operate in accordance with the following tenms of reference: A. Membership The Committee will be composed of four representatives, one from each of the participating Governments. It will be jointly chaired by the Govemment of Canada and the Government of the United States. There will be a Canadian Section and a United States Section. The participating Governments will notify each other of any changes in membership on the Committee. Co- chairpersons may by mutual agreement invite agency technical experts to participate in the work of the Committee. The Governor of the State of Montana may also appoint a chief elective official of local govemment to participate as an ex-officio member of the Committee in its technical deliberations. The Saskatchewan Minister of the Environment may also appoint a similar local representative. B. Functions of the Committee The role of the Committee will be to fulfill the purpose of the Arrangement by ensuring the exchange of monitored data in accordance with the attached Technical Monitoring Schedules, and its collation and technical interpretation in reports to Governments on implementation of the Arrangement. In addition, the Committee will review the existing monitoring systems to ensure their adequacy and A1-2 may recommend to the Canadian and United States Govemments any modifications to improve the Technical Monitoring Schedules. 1. Information Exchange Each Co-chairperson will be responsible for transmitting to his counterpart Co-chairperson on a regular, and not less than quarterly basis, the data provided by the cooperative monitoring agencies in accordance with the Technical Monitoring Schedules. 2. Reports (a) The Committee will prepare a joint Annual Report to the participating governments, and may at any time prepare joint Special Reports. (b) Annual Reports will i) summarize the main activities of the Committee in the year under Report and the data which has been exchanged under the Arrangement; ii) draw to the attention of the participating govemments any definitive changes in the monitored parameters, based on collation and technical interpretation of exchanged data (i.e. the utilization of summary, statistical and other appropriate techniques); iii) draw to the attention of the participating govemments any recommendations regarding the adequacy or redundancy of any scheduled monitoring operations and any proposals regarding modifications to the Technical Monitoring Schedules, based on a continuing review of the monitoring programs including analytical methods to ensure their comparability. (c) Special Reports may, at any time, draw to the attention of participating governments definitive changes in monitored parameters which may require immediate attention. (d) Preparation of Reports Reports will be prepared following consultation with all committee members and will be signed by all Committee members. Reports will be separately fon^^arded by the Committee Co-chairmen to the participating governments. All annual and special reports will be so distributed. 3. Activities of Canadian and United States Sections The Canadian and United States sections will be separately responsible for: (a) dissemination of information within their respective countries, and the arrangement of any discussion required with local elected officials; (b) verification that monitoring operations are being carried out in accordance with the Technical Monitoring Schedules by cooperating monitoring agencies; (c) receipt and collation of monitored data generated by the cooperating agencies in their respective countries as specified in the Technical Monitoring Schedules; (d) if necessary, drawing to the attention of the appropriate government in their respective countries any failure to comply with a scheduled monitoring function on the part of any cooperating agency under the jurisdiction of that government, and requesting that appropriate corrective action be taken. A1-3 IV. PROVISION OF DATA In order to ensure that the Committee is able to carry out the terms of this Arrangement, the participating govemments will use their best efforts to have cooperating monitoring agencies, in their respective jurisdictions provide on an ongoing basis all scheduled monitored data for which they are responsible. V. TERMS OF THE ARRANGEMENT The Arrangement will be effective for an initial term of five years and may be amended by agreement of the participating govemments. It will be subject to review at the end of the initial term and will be renewed thereafter for as long as it is required by the participating govemments. A1-4 ANNEX 2 POPLAR RIVER COOPERATIVE MONITORING ARRANGEMENT TECHNICAL MONITORING SCHEDULES 1993 CANADA-UNITED STATES A2-1 TABLE OF CONTENTS PREAMBLE A2-3 CANADA STREAMFLOW MONITORING A2-5 SURFACE-WATER QUALITY MONITORING A2-7 GROUND-WATER QUALITY MONITORING A2-11 GROUND-WATER PIEZOMETER TO MONITOR POTENTIAL DRAWDOWN DUE TO COAL SEAM DEWATERING A2-13 GROUND-WATER PIEZOMETER LEVEL MONITORING - ASH LAGOON AREA SCHEDULE A - PIEZOMETER IN TILL A2-15 GROUND-WATER PIEZOMETER LEVEL MONITORING - ASH LAGOON AREA AND INTERNATIONAL BOUNDARY AREA SCHEDULE B - PIEZOMETER IN EMPRESS GRAVEL A2-17 AMBIENT AIR QUALITY MONITORING A2-19 UNITED STATES STREAMFLOW MONITORING A2-22 SURFACE-WATER QUALITY MONITORING A2-24 GROUND-WATER QUALITY MONITORING A2-26 GROUND-WATER LEVELS TO MONITOR POTENTIAL DRAWDOWN DUE TO COAL SEAM DEWATERING A2-28 A2-2 PREAMBLE The Technical Monitoring Schedule lists those water quantity, water quality, and air quality monitoring locations and parameters which form the basis for information exchange and reporting to Govemments. The structure of the Committee responsible for ensuring the exchange takes place is described in the Poplar River Cooperative Monitoring Arrangement. The monitoring locations and parameters listed herein have been reviewed by the Poplar River Bilateral Monitoring Committee and represent the basic technical information needed to identify any definitive changes in water quantity, water quality, and air quality at the Intemational Boundary. The Schedule was initially submitted to Governments for approval as an attachment to the 1981 report to Govemments. Changes in the sampling locations and parameters may be made by Governments based on the recommendation of the Committee. Significant additional information is being collected by agencies on both sides of the Intemational Boundary, primarily for project management or basin-wide baseline data purposes. This additional information is usually available upon request from the collecting agency and forms part of the pool of technical information which may be drawn upon by Governments for specific study purposes. Examples of additional information are data on water quantity water quality, ground water, and air quality collected at points in the Poplar River basin not of direct concern to the Committee. In addition, supplemental information on parameters such as vegetation, soils, fish, and waterfowl populations and aquatic vegetation Is also being collected as part of routine or specific studies by various agencies. A2-3 POPLAR RIVER COOPERATIVE MONITORING ARRANGEMENT TECHNICAL MONITORING SCHEDULES 1993 CANADA A2-4 STREAMFLOW MONITORING Responsible Agency: Environment Canada Daily mean discharge or levels and instantaneous monthly extremes as nomally published in surface water data publications. No. on Map Station No. Station Name *1 11AE003 (06178500) East Poplar River at Intemational Boundary 2 11AE013 Cookson Reservoir near Coronach 3 11AE015 Girard Creek near Coronach above Cookson Resen/oir 4 11AE014 East Poplar River above Cookson Reservoir 5 **Fife Lake Overflow *6 11AE008 (06178000) Poplar River at International Boundary Intemational gauging station Miscellaneous measurements of outflow to be made by Sask Water during periods of outflow only. A2-5 0 5 10 15 Km 1 I I I I I 0 5 10 Miles HYDROMETRIC GAUGING STATIONS (CANADA) A2-6 SURFACE-WATER QUALITY MONITORING Sampling Locations Responsible Agency: Saskatchewan Environment and Resource lUanagement No. on Map Station No. Station Name 1 7904 Fife Lal