s 333.91 M26PRAR 2003 2003 ANNUAL REPORT to the GOVERNMENTS OF CANADA, UNITED STATES, SASKATCHEWAN AND MONTANA by the POPLAR RIVER BILATERAL MONITORING COMMIHEE COVERING CALENDAR YEAR 2003 \ \{k /STATE DOCUMENTS COLLECTION Scobey JAN 1 4 2005 MONTANA STATE LIbKARY 1515 E. 6th AVE. HELENA r«ONTAM^ 5962C November 2004 ktontana Stats Ubmi 3 0864 1003 2744 7 2003 ANNUAL REPORT to the GOVERNMENTS OF CANADA, UNITED STATES, SASKATCHEWAN, AND MONTANA by the POPLAR RIVER BILATERAL MONITORING COMMITTEE COVERING CALENDAR YEAR 2003 November 2004 Poplar River Bilateral Monitoring Committee Department of State Washington, D.C., United States Governor's Office State of Montana Helena, Montana, United States Ladies and Gentlemen: Department of Foreign Affairs and International Trade Canada Ottawa, Ontario, Canada Saskatchewan Environment Regina, Saskatchewan, Canada Herein is the 23rd Annual Report of the Poplar River Bilateral Monitoring Committee. This report discusses the Committee activities of 2003 and presents the Technical Monitoring Schedules for the year 2004. During 2003, the Poplar River Bilateral Monitoring Committee continued to fulfil the responsibilities assigned by the governments under the Poplar River Cooperative Monitoring Agreement dated September 23, 1980. Through exchange of Diplomatic Notes in March 1987, July 1992, July 1997, and March 2002, the Arrangement was extended. The Monitoring Committee is currently extended to March 2007. The enclosed report summarizes current water-quality 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 evaluation of the monitoring information for 2003, the Committee finds that the measured conditions meet the recommended objectives including boron and total dissolved solids (TDS). Concems over an upward trend in the concentrations of TDS in the East Poplar River between the late 1980's and 1995 were investigated. The results of the investigation indicated that the temporal changes in TDS concentrations were most likely primarily linked to natural drought events. Based on UC recommendations, the United States was entitied to an on-demand release of 370 dam^ (300 acre- feet) from Cookson Reservoir in 2003. A volume of 386 dam^ (313 acre-feet) was delivered to the United States during this period. In addition, daily flows in 2003 met or exceeded the minimum flow recommended by the UC except for June 7-11, June 13 to September 9, September 11, and December 28-31. Several changes were made in the Technical Monitoring Schedules for the year 2003. The ground-water monitoring network operated by SaskPower was reduced from 180 piezometers to about 85 piezometers after receiving approval from Saskatchewan Environment. This reduction was based upon modelling studies undertaken by SaskPower. In 2003, due to a reduction in available funding and using specific conductance to estimate TDS, the number of surface-water-quality samples collected at both Poplar River boundary stations by the U.S. Geological Survey was reduced from six per year to four per year. In 2004, the number of surface-water- quality samples collected at these stations will be reduced further, with the U.S. Geological Survey collecting four samples and Environment Canada collecting none. Yours sincerely, Robert Davis ChairmanJJnited States Sectron Richard Kellow Chairman, Canadian Section ^Stults lember. United States Section TABLE OF CONTENTS Highlights for 2003 iii 1.0 Introduction 1 2.0 Committee Activities 2 2.1 Membership 2 2.2 Meetings : 2 2.3 Review of Water-Quality Objectives 3 2.4 Data Exchange 4 3.0 Water and Air: Monitoring and Interpretations 6 3.1 Poplar River Power Station Operation 6 3.2 Surface Water 6 3.2.1 Streamflow 6 3.2.2 Apportionment 7 3.2.3 Minimum Flows 7 3.2.4 On-Demand Release 8 3.2.5 Surface- Water Quality 9 3.2.5.1 Total Dissolved Solids 10 3.2.5.2 Boron 15 3.2.5.3 Other Water-Quality Variables 16 3.3 Groundwater 18 3.3.1 Operations 18 3.3.2 Ground- Water Monitoring 20 3.3.2.1 Saskatchewan 21 3.3.2.2 Montana 23 3.3.3 Ground- Water Quality 25 3.3.3.1 Saskatchewan 25 3.3.3.2 Montana 29 3.4 Cookson Reservoir 30 3.4.1 Storage 30 3.4.2 Water Quality 32 3.5 Air Quality 32 3.6 Quality Control 32 3.6.1 Streamflow 32 3.6.2 Water Quality 33 ANNEXES 1 .0 Poplar River Cooperative Monitoring Arrangement, Canada-United States Al 2.0 Poplar River Cooperative Monitoring Arrangement, Technical Monitoring Schedules, 2004, Canada-United States A2 3.0 Recommended Flow Apportionment in the Poplar River Basin A3 4.0 Conversion Factors A4 TABLES Table 2.1 Water-Quality Objectives 5 Table 3.1 Recommended Water-Quality Objectives and Excursions, 2003 Sampling Program, East Poplar River at International Boundary 17 Table 3.2 Geologic Formation Name Equivalence between Saskatchewan and Montana 20 Table 3.3 Water-Quality Statistics for Water Pumped from Supplementary Water Supply Project Wells 25 Table 3.4 Water-Quality Statistics for Water Pumped from Salinity Control Project Wells Sampled at the Discharge Pipe 26 Table 3.5 Cookson Reservoir Storage Statistics for 2003 30 Table 3.6 Streamflow Measurement Results for August 6, 2003 33 Table 3.7 East Poplar River Joint Water-Quality Sample Results for September 9, 2003 34 FIGURES Figure 3.1 Discharge during 2003 as Compared with the Median Discharge from 1931-2000 for the Poplar River at International Boundary 6 Figure 3.2 Flow Hydrograph of the East Poplar River at International Boundary 8 Figure 3.3 Cumulative Volume Hydrograph of On-Demand Release 9 Figure 3.4 TDS Concentration for 2003 Water-Quality Samples from East Poplar River at the International Boundary 12 Figure 3.5 Three-Month Moving Flow-Weighted TDS Concentration in 2003 for East Poplar River at the International Boundary 12 Figure 3.6 Five- Year Moving Flow- Weighted TDS Concentration in 2003 for East Poplar River at the International Boundary 14 Figure 3.7 Daily TDS Concentration, 1990 to 2003; East Poplar River at the International Boundary 14 Figure 3.8 Daily Boron Concentration, 1990 to 2003; East Poplar River at the International Boundary 16 Figure 3.9 Supplementary Water Supply 18 Figure 3.10 Pumpage from Salinity Control Project 20 Figure 3.11 Hydrograph of Selected Wells - Cookson Reservoir Supplementary Supply 22 Figure 3.12 Hydrograph of Selected Wells - Cookson Reservoir Supplementary Supply 22 Figure 3.13 Hydrograph of Selected Wells - Fort Union and Hart Coal Aquifers 23 Figure 3.14 Hydrograph of Selected Wells - Alluvium and Fox Hills Aquifers 24 Figure 3.15 Total Dissolved Solids in Samples from Montana Wells 29 Figure 3.16 Cookson Reservoir Daily Mean Water Levels for 2003 and Median Daily Water Levels, 1993-2002 31 HIGHLIGHTS FOR 2003 The Poplar River Power Station completed its twentieth full year of operation in 2003. The two 300-megawatt coal-fired units generated 4,470,455 gross megawatt hours (MWh) of electricity. The average capacity factors for Units No. 1 and 2 were 84.5 percent and 83.0 percent, respectively. The capacity factors are based on the maximum generating rating of 305 MW/h for both Unit No. 1 and Unit No. 2. Similar to other years, scheduled maintenance was completed in the spring and fall of 2003. Monitoring information collected in both Canada and the United States during 2003 was exchanged in the spring of 2004. Several changes were made in the Technical Monitoring Schedules for the year 2003. The ground- water monitoring network operated by SaskPower was reduced from 180 piezometers to about 85 piezometers after approval from Saskatchewan Environment. This reduction was based upon modeling studies undertaken by SaskPower. In 2003, due to a reduction in available fiinding and using specific conductance to estimate total dissolved solids (TDS), the number of surface-water-quality samples collected at both Poplar River boundary stations by the U.S. Geological Survey was reduced from six per year to four per year. In 2004, the number of surface-water-quality samples collected at these stations will be reduced further, with the U.S. Geological Survey collecting four samples and Environment Canada collecting none. The recorded volume of the Poplar River at International Boundary from March 1 to May 3 1 , 2003 was 10,050 dam^ (8,150 acre-feet). Based on International Joint Commission (IJC) recom- mendations 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 0.085 cubic metres per second (mVs) (3.0 cubic feet per second (ft^/s)) for the period June 1, 2003 to August 31, 2003 and 0.057 m^/s (2.0 ftVs) for the period September 1, 2003 to May 31, 2004. The minimum flow of 0.028 mVs (1.0 ft^/s) for the period January 1 to May 31, 2003 had previously been determined on the basis of the Poplar River flow volume for March 1 to May 3 1 , 2002. Daily flows in 2003 met or exceeded the minimum flow recommended by the IJC except for June 7-11, June 13 to September 9, September 1 1 , and December 28-3 1 . In addition to the minimum flow, the IJC apportiormient recommendation entitles the United States to an on-demand release to be delivered on the East Poplar River during the twelve-month period commencing June 1. Based on the runoff volume of 3,960 dam^ (3,210 acre-feet) recorded at the Poplar River at International Boundary gauging station for March 1 through May 31, 2002, the United States was entitled to an additional release of 370 dam^ (300 acre-feet) from Cookson Reservoir during the succeeding twelve-month period commencing June 1, 2002. Montana requested this release to be made between May 1 and May 31, 2003. A volume of 386 dam^ (313 acre-feet), in addition to the minimum flow, was delivered during this period. The 2003 five-year TDS flow-weighted concentrations were below the long-term objective of 1,000 milligrams per litre (mg/L). The maximum monthly value calculated in 2003 was 887 mg/L, which was less than the maximum monthly value in 2002. Boron water-quality sample data was incomplete and no analysis was conducted. Ill 1.0 INTRODUCTION The Poplar River Bilateral Monitoring Committee was authorized for an initial period of five years by the Governments 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. Through exchange of Diplomatic Notes, the Arrangement was extended in March 1987, July 1992, July 1997, and March 2002. The current extension expires in March 2007. A more detailed account of the historical background of the Monitoring Arrangement is contained in the 1 990 Annual Report of the Poplar River Bilateral Monitoring Committee. The Committee oversees monitoring programs designed to evaluate the potential for transboundary impacts from SaskPower's (formerly Saskatchewan Power Corporation) coal-fired thermal 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 the data to objectives or standards recommended by the International Joint Commission (IJC) to Governments, or relevant State, Provincial, or Federal standards. The Committee reports to Governments on a calendar year basis. The Committee is also responsible for drawing to the attention of Governments definitive changes in monitored parameters which may require immediate attention. A responsibility of the Committee is to review the adequacy of the monitoring programs in both countries and make recommendations to Governments on the Technical Monitoring Schedules. The Schedules are updated annually for new and discontinued programs and for modifications in sampling frequencies, parameter lists, and analytical techniques of ongoing programs. The Technical Monitoring Schedules listed in the annual report (Annex 2) are given for the year 2004. The Committee will continue to review and propose changes to the Technical Monitoring Schedules as information requirements change. 2.0 COMMITTEE ACTIVITIES 2.1 Membership The Committee is composed of representatives of the Governments of the United States of America and Canada, the State Government of Montana, and the Provincial Government of Saskatchewan. In addition to the representatives of Governments, two ex-officio members serve as local representatives for the State of Montana and Province of Saskatchewan. During 2003, the members of the Committee included: Mr. R. Davis, U.S. Geological Survey, United States representative and Cochair; Mr. R. Kellow, Environment Canada, Canadian representative and Cochair; Mr. J. Stults, Montana Department of Natural Resources and Conservation, Montana representative; Mr. C. Bosgoed, Saskatchewan Environment, Saskatchewan representative; Mr. C.W. Tande, Daniels County Commissioner, Montana local ex-officio representative; and Mr. J.R. Totten, Reeve, R.M. of Hart Butte, Saskatchewan local ex-officio representative. 2.2 Meetings The Committee met on June 17-18, 2003, in Helena, Montana. Delegated representatives of Governments, with the exception of the two ex-officio members from Montana and Saskatchewan, attended the meeting. 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 Poplar River Power Station and associated coal-mining activities; examined data collected in 2002 including surface-water quality and quantity, ground-water quality and quantity, and air quality; discussed proposed changes in the water-quality sampling program, and established the Technical Monitoring Schedules for the year 2004. In 2003, due to a reduction in available funding and using specific conductance to estimate total dissolved solids (TDS), the number of surface-water-quality samples collected at the Poplar River stations by the U.S. Geological Survey was reduced from six per year to four per year. In 2004, the number of surface-water-quality samples collected at these stations will be reduced ftirther, with the U.S. Geological Survey collecting four samples and Environment Canada none. 2.3 Review of Water-Quality Objectives The International Joint Commission in its Report to Governments, titled "Water Quality in the Poplar River Basin", recommended that the Committee "periodically review the water-quality objectives with the overall Basin context and recommend new and revised objectives as appropriate". In 1991, an action item from the armual Committee meeting set in motion the review and revision of the water-quality objectives. In 1993, the Committee approved changes in water-quality objectives recommended by the subcommittee that was formed in 1992 to review the objectives. The Committee also discussed the water-quality objectives for 5-year and 3-month flow-weighted concentrations for total dissolved solids and boron. Although the Committee 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. In 1997, the Committee agreed to suspend the monitoring and reporting of several parameters. The parameters affected were: dissolved aluminum, un-ionized ammonia, total chromium, dissolved copper, mercury in fish tissues, fecal coliform, and total coliform. The Committee also agreed to other minor revisions for clarification purposes. For example, changing the designation for pH from "natural" to "ambient". In 1999, the Committee replaced the term "discontinued" with "suspended" in Table 2.1. In 2001, the Committee suspended the monitoring of dissolved mercury and total copper. This decision to suspend these parameters was based on data indicating concentrations or levels well below or within the objectives. Current objectives approved by the Committee are listed in Table 2.1. The Committee also agreed to periodically review all suspended parameters. Another responsibility of the Committee has included an ongoing exchange of data acquired through the monitoring programs. Exchanged data and reports are available for public viewing at the agencies of the participating governments or from Committee members. 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 1 98 1 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 1992 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 data will be reported and exchanged whenever warranted. No unusual conditions occurred during 2003 which warranted special reporting. Table 2.1 Water-Quality Objectives Parameter Present Objective Recommendation New Objective Boron, total 3.5/2.5' Continue as is — TDS 1500/1000' Continue as is — Aluminum, dissolved 0.1 Suspend* — Ammonia, un-ionized 0.02 Suspend* — Cadmium, total 0.0012 Continue as is 0.0012 Chromium, total 0.05 Suspend* — Copper, dissolved 0.005 Suspend* — Copper, total 1 Suspend* — Fluoride, dissolved 1.5 Continue as is 1.5 Lead, total 0.03 Continue as is 0.03 Mercury, dissolved 0.0002 Suspend* — Mercury, fish (mg/kg) 0.5 Suspend* — Nitrate 10 Continue as is 10 Oxygen, dissolved 4.0/5.0^ Objective applies only during open water 4.0/5.0^ SAR (units) 10 Continue as is 10 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 6.5^ Coliform(no./100mL) Fecal 2000 Suspend* ... Total 20000 Suspend* ... Units in mg/L except as noted. 1. Five-year average of flow- weighted concentrations (March to October) should be <2.5 boron, <1,000 TDS. Three-month average of flow-weighted concentration should be <3.5 boron and < 1500 TDS. 2. 5.0 (minimum April 10 to May 1 5), 4.0 (minimum remainder of year - Fish Spawning). 3. Natural temperature (April lOtoMay 15), <30 degree Celsius (remainder of year) .. 4. Less than 0.5 pH units above ambient, minimum pH=6.5. *Suspended after review of historic data found sample concentrations consistently below the objective. The Committee will periodically review status of suspended objectives. 3.0 WATER AND AIR: MONITORING AND INTERPRETATIONS 3.1 Poplar River Power Station Operation In 2003, the two 300-megawatt coal-fired units generated 4,470,455 gross megawatt hours (MWh) of electricity. The average capacity factors for Unit No. 1 and 2 were 84.5 percent and 83.0 percent, respectively. The capacity factors are based on the maximum generating rating of 305 MW/h for both Unit No.l and Unit No. 2. Similar to other years, scheduled maintenance was completed in the spring and fall of 2003. 3.2 Surface Water 3.2.1 Streamflow Streamflow in the Poplar River basin was normal in 2003. The March to October recorded flow of the Poplar River at International Boundary, an indicator of natural flow in the basin, was 10,700 cubic decametres (dam^) (8,670 acre-feet), which was 104 percent of the 1931 to 2000 median seasonal flow of 10,290 dam^ (8,340 acre-feet). A comparison of 2003 monthly mean discharge with the 1931-2000 median monthly mean discharge is shown in Figure 3.1. ° - Median of Monthly Mean Discharge for 1931-2000 o — Monthly Mean Discharge for 2003 Apr May Jun Jul Aug Sep Figure 3.1 Discharge during 2003 as Compared with the Median Discharge from 1931-2000 for the Poplar River at International Boundary. The 2003 recorded flow volume of the East Poplar River at International Boundary was 2,300 dam^ (1,860 acre-feet). This volume is 77 percent of the median annual flow of 2,980 dam^ (2,420 acre-feet) for 1975-2002 (since the completion of Morrison Dam). 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 apportion- ment recommendations in each of its annual reports. Armex 3 contains the apportionment recommendation. 3.2.3 Minimum Flows The recorded volume of the Poplar River at International Boundary from March 1 to May 3 1 , 2003 was 10,050 dam^ (8,150 acre-feet). 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 0.085 cubic metres per second (mVs) (3.0 cubic feet per second (ftVs)) for the period June 1, 2003 to August 31, 2003 and 0.057 m^/s (2.0 ftVs) for the period September 1, 2003 to May 31, 2004. The minimum flow for the period January 1 to May 31, 2003 was 0.028 mVs (1.0 ftVs), determined on the basis of the Poplar River flow volume for March 1 to May 31, 2002. A hydrograph for the East Poplar River at International Boundary and the minimum flow as recommended by the IJC are shown in Figure 3.2. ,.„.;■ , ., . Daily flows during 2003 met or exceeded the minimum flow recommended by the IJC throughout the year except for June 7-11, June 13 to September 9, September 11 and December 28-31, when daily flows fell below the recommended minimum. C C C A A an na>ai"«5-33io»3 3r^^33 ••i'iji' oo« so •?TTU.u.SS<<c*>*kCno)^ot>tDO-»>N3W^aia)-Nioo-^ ■v_ u r^ ~\. fV 0)0)0)0)0)0)0)0) 0) 0) 0) 0) 03 Qj 0}0}Q}Q)Q>Q)fl>0)0}Q>Q}fl}Q}0> •^ -^ 00 00 00 00 00 CD o -^ ro od 00 00 00 CO CD CO CO CiD CO CD CD CD Figure 3.7: Daily TDS Concentration, 1990 to 2003; East Poplar River at the International Boundary (regression-derived data) 1400 Q 600 14 3.2.5.2 Boron Boron water-quality sample data for 2003 at the East Poplar River at International Boundary was incomplete and no flow-weighted concentration analysis was conducted. In 2004, only four boron water-quality samples will be available for analysis. Boron concentrations are not as well-correlated with specific conductance as TDS. Boron is a relatively minor ion, and does not in itself contribute to a large degree to the total load of dissolved constituents in the water. Accordingly, it appears likely that the standard deviation of dissolved boron (relative to the long-term mean boron concentration) may be greater than that of the major cations (sodium, potassium, and magnesium) and anions (sulphate, bicarbonate, and chloride) around their respective long-term mean concentrations. The relationship between boron and specific conductance applied to data collected from 1974 to 2002 is as follows: Boron = (0.00129 x specific conductance) - 0.04709 (R^ = 0.57, n = 617) The daily boron values, as generated by linear regression, for the period January 1990 through December 2003 are shown in Figure 3.8. 15 3.00 2.50 2.00 1.50 1.00 0.50 Figure 3.8: Daily Boron Concentration, 1990 to 2003; East Poplar River at the International Boundary (regression-derived data) 3.2.5.3 Other Water-Quality Variables Table 3.1 contains the multipurpose water-quality objectives for the East Poplar River at International Boundary, recommended by the International Poplar River Water Quality Board to the IJC. The table shows the number of samples collected for each parameter and the number of times over the course of the year that the objectives were exceeded. In the table, multiple replicate samples collected during the annual quality control exercise are treated as a single sample, but where an objective was exceeded in a replicate sample, this is charged against the single sample noted. As the table shows, all parameters were within the appropriate objectives. 16 Table 3.1 Recommended Water-Quality Objectives and Excursions, 2003 Sampling Program, East Poplar River at the International Boundary (units in m g/L, except as otherwise noted Parameter Objective No. of Samples Excursions USA Canada Objectives recommended by IJC to Governments | Boron, dissolved 3.5/2.5 (1) 0 6 0 Total Dissolved Solids 1,500/1,000(1) 4 6 0 Objectives recommended by Poplar River Bilateral Monitoring Committee to Governments 1 Cadmium, total 0.0012 4 6 0 Fluoride, dissolved 1.5 4 6 0 Lead, total 0.03 4 6 0 Nitrate 10.0 4 6 0 Oxygen, dissolved 4.0/5.0 (2) 4 6 0 Sodium adsorption ratio 10.0 4 5 0 Sulphate, dissolved 800.0 4 6 0 Zinc, total 0.03 4 6 0 Water temperature (Celsius) 30.0 (3) 4 6 0 pH (pH units) 6.5 (4) 4 6 0 (1) Three-month average of flow-weighted concentrations should be <3.5 mg/L boron and < 1,500 mg/L ' flow-weighted concentrations (March to October) should be <2.5 mg/L boron and <1,000 mg/L TD (2) 5.0 (minimum April 10 to May 15), 4.0 (minimum, remainder of the year). (3) Natural temperature (April 10 to May 1 5), <30 degrees Celsius (remainder of the year). (4) Less than 0.5 pH units above natural, minimum pH = 6.5. ~DS. Five-year average of S. 17 3.3 Ground Water 3.3.1 Operations SaskPower's supplementary water supply project continued to operate during 2003. The supplementary water supply project currently consists of 21 wells with a total of 10 discharge points. No wells were added or deleted from the well field during the year. The majority of ground-water production in 2003 occurred during the fall to spring period. This is a typical operational pattern for the project and is done to minimize water losses. However, pumping was maintained through the 2003 summer period due to low spring runoff. In 2003, ground-water production decreased to 4,489 dam^ from the 2002 total of 4,927 dam^ total. Production from 1991 to 2003 has now averaged 4,998 dam^ per year. Prior to 1991, the wells used for supplementary supply were part of a dewatering network for coal-mining operations. This resulted in the high production levels experienced in the early to mid 1980's. With the drought of the late 1980's and early 1990's, it was evident that there was a continued need for ground water to supplement water levels in Cookson Reservoir. Consequently, the wells were taken over by SaskPower for use as a supplementary supply. Poplar River Power Station - Supplementary Supply 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year Figure 3.9 Supplementary Water Supply 18 SaskPower has an approval for the supplementary supply project to produce an annual volume of 5,500 damVyear. This approval was extended by Sask Water in 1996. Future revisions to the approval will likely include conditions requiring termination of pumping (with the exception of wells supplying domestic users) when the reservoir is above a specified level. In addition to the supplementary supply, SaskPower also operates the Soil Salinity Project, which is located south of Morrison Dam. The project was initiated in 1989 to alleviate soil salinity which had developed below the dam. The salinity project consists of a network of production wells which discharge into the cooling water canal, which in turn discharges to Cookson Reservoir. Operation of the salinity project continued in 2003 despite ongoing operational difficulties which resulted in a continued decline in the annual volume pumped. As a result, only 426 dam^ of ground water was pumped fi-om the Soil Salinity Project in 2003. This was much lower than the 2002 production level of 631 dam^, and substantially lower than the average armual production obtained in the early to mid- 1 990 's when production was near its optimal level. Production levels peaked at about 1,100 dam^/year in 1994. SaskPower expects to increase production levels in 2004 with additional rehabilitation work. Well PW87104, which is located on the east side of the river, provided all the production in 2003. 19 Poplar River Power Station - Salinity Project 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 Figure 3.10 Pumpage from Salinity Control Project 3.3.2 Ground-Water Monitoring Equivalent geologic formations present in Saskatchewan and Montana have different names. A list of the corresponding formation names is provided in Table 3.2. Table 3.2 Geologic Formation Name Equivalence between Saskatchewan and Montana Formation Location Geologic Formation Name Saskatchewan Eastend to Whitemud Frenchman Ravenscrag Alluvium Montana Fox Hills Hell Creek Fort Union Alluvium 20 3.3.2.1 Saskatchewan In 2003, SaskPower reduced its monitoring network from 180 piezometers to about 85 piezometers after receiving approval from Saskatchewan Environment. This reduction was based on modelling studies undertaken by SaskPower. In past years the groundwater response to pumping has been illustrated through a regional drawdown map prepared by SaskPower. However, the 2003 drawdown map indicated an apparent expansion in the cone of depression in the vicinity of the International Boundary during 2003. Given that the 2003 withdrawals were the lowest in the past four years, and one of the lowest in the past 13 years, the apparent expansion was anomalous. This was confirmed by the absence of any significant increases in drawdown in Montana's monitoring wells (Figure 3.13). It was therefore decided to incorporate hydrographs for several monitoring wells near the border as opposed to the drawdown map. Hydrographs of these selected wells are shown in Figures 3.11 and 3.12. While there are some anomalous data points in the hydrographs, they do clearly show that there have not been significant changes in groundwater levels in the Hart Coal seam at the international boimdary in the past ten years. Of particular note are monitoring wells M81 1 and M507 along the international boundary. The goal of the Salinity Control Project is to lower ground-water levels in the Empress sands below Morrison Dam to approximately pre-reservoir levels. This is equivalent to roughly two to three mefres of drawdown, and was achieved by the end of 1995 and again by the end of 1996. However, reduced production over the past several years and increased recharge from higher reservoir levels and precipitation has led to a significant contraction in the project's cone of depression with the cone of depression being negligible at the end of 2003. 21 Cookson Reservoir Supplementary Supply Groundwater Monitoring Network ■ ■■ ■■■ M, • ■""■■"" i' WMM J ^,^ i ^^* ' ♦%' ♦♦, i ♦♦♦ 4 ♦!♦ ♦ ♦ « * ♦ « ♦/ ♦ < ♦ ♦♦' ♦♦•< — WellM811 K-WellM782 t-WellM510A OOOOOOOOOOOOOOOOO Figure 3.11 Hydrograph of Selected Wells — Cookson Reservoir Supplementary Supply Cookson Reservoir Supplementary Supply Groundwater Monitoring Network z IMM^ mm tm* -, •1 rf*Si IMMN MMMM M M* MM« ^ lUHk f r** A i 1 M. ' M»H »mmn u uJt ■P K/XI ■». ^ .*■ 1. *^ «M pa* ^w T -Well M492A -WellM507 -Well M509 OOOOOOOOOOOOOO Figure 3.12 Hydrograph of Selected Wells — Cookson Reservoir Supplementary Supply 22 3.3.2.2 Montana Water-levels in monitoring wells (6, 7, 9, 13, 16, 17, 19, and 22) that penetrate the Fort Union Formation and/or Hart Coal Seam were rising during 1997 and 1998, and have leveled off or decreased during the last five years (1999 to 2003). Hydrographs of selected Fort Union and Hart Coal Seam wells (6, 7, 17, and 19) are shown in figure 3.13. Hydrograph of Selected Wells Fort Union and Hart Coal Aquifers -Well 6 -Well 7 -Well 17 -Well 19 CO CO CO 00 cbooGoooooo>ooo>^d)0)0)o>o)ooooooo <0(0(Dfl3Ct](T]n](Q(Q(D(D(D(OCDn)(13(Ofl3CDCO(D(DCO{a(0(U(0(D —> —i —3 —> ~y —i —3 —> —i Figure 3.13 Hydrograph of Selected Wells — Fort Union and Hart Coal Aquifers 23 The potentiometric surface in the Fox Hills/Hell Creek artesian aquifer (well 11) has shown very little fluctuation or change throughout the 25-year (1979-2003) monitoring period. Water levels in monitoring wells (5, 8, 10, 23, and 24) that penetrate the alluvial and/or outwash aquifer show considerable fluctuation due to seasonal and/or pumping changes. Hydrographs of selected alluvial wells (10, 23, and 24) and the Fox Hills well (11) are shown in Figure 3.14. Hydrograph of Selected Wells Alluvium and Fox Hills Aquifers -Well 10 -Well 11 -Well 23 -Well 24 CD (Q (C ra CD (Q m (0 Figure 3.14 Hydrograph of Selected Wells — Alluvium and Fox Hills Aquifers 24 3.3.3 Ground-Water Quality 3.3.3.1 Saskatchewan The water quality from the Supplementary Supply Project discharge points has been consistent with no trends indicated. A summary of the more frequently tested parameters during 2003 is provided in Table 3.3. Statistical averages of the results since 1992 are included in this table. Table 3.3 Water-Quality Statistics for Water Pumped from Supplementary Water Supply Project Wells* 2003 Average 1992 - 2003 Average pH (unit) 8.1 8.0 Conductivity (^S/cm) 1,387 1,316 Total Dissolved Solids 945 910 Total Suspended Solids 26 10.9 Boron 1.2 1.2 Sodium 191 179 Cyanide (jig/L) <0.004 <2 Iron 0.17 0.2 Manganese 0.09 0.1 Mercury (|ig/L) <0.05 <0.1 Calcium 68.7 72 Magnesium 48.2 52 Sulfate 271 269 Nitrate 0.01 0.07 *A11 units in mg/L, unless otherwise noted. Sampled at Site "C3" on Girard Creek. 25 Average water-quality results from the common discharge point for the Salinity Control Project for 2003, plus an average of the 1992-2003 results, are provided in Table 3.4. Results have remained relatively consistent since 1992. Table 3.4 Water-Quality Statistics for Water Pumped from Salinity Control Project Wells Sampled at the Discharge Pipe* 2003 Average 1992-2003 Average pH (units) 7.8 7.5 Conductivity (^iS/crn) 1,479 1,410 Total Dissolved Solids 1,050 981 1 Boron 1.5 1.6 1 Calcium 121 103 Magnesium 65 60 Sodium 145 146 Potassium 7.4 7.4 Arsenic (ng/L) 7.0 8.1 Aluminum <0.1 0.1 Barium <0.1 <0.1 Cadmium <0.01 <0.003 Iron 4.0 4.1 Manganese 0.10 0.136 Molybdenum <0.1 <0.01 1 Strontium 1.8 1.8 Vanadium <0.1 <0.1 Uranium (^g/L) <0.5 <0.2 Mercury (|ig/L) <0.05 0.08 Sulfate 362 314 Chloride 6.6 6.2 Nitrate <0.003 <1.04 *A11 concentrations in mg/L, unless otherwise noted. 26 Ground-water quality in the vicinity of the ash lagoons can potentially be affected by leachate movement through the ash lagoon liner systems. The piezometers listed in the Technical Monitoring Schedules are used to assess leachate movement and calculate seepage rates. Piezometric water level, boron, and chloride are the chosen indicator parameters to assess leachate movement. The groimd- water monitoring program was expanded in 1994 as a result of Ash Lagoon No. 3 South construction. In total, 20 new pneumatic piezometers and 28 new standpipe piezometers were completed within their target zones. Testing of these piezometers began in 1995. The limited data so far do not show any unusual or unexpected values. Piezometers C867A, C868A and C871A are completed immediately above the liner system, within the ash stack of Ash Lagoon No. 1 . The 2003 monitoring results continue to suggest confirmation of the trend first observed in 1993 that the boron concentration decreases with depth within the ash stack. The effect of ash thickness on leachate quality is, however, not completely understood. The chemistry of water immediately above the liner systems is therefore expected to differ fi-om the surface water of the lagoons. Meaningful information is only available fi-om piezometers installed within Ash Lagoon No. 1 where ash has been deposited for many years. The 2003 monitoring results of Ash Lagoon No. 3 South piezometers completed above the liner system (piezometers C886A, C887A, C890A and C893A) supports the theory that boron levels decrease with depth within the ash stacks. Future monitoring of all piezometers completed above the lagoon liner systems will continue with the purpose of confirming the boron trend noted above and to improve the understanding of leachate quality and flow fi-om the ash lagoons. The piezometric surface measurements for the oxidized till continue to show the presence of a ground- water mound beneath the ash lagoons. The mound extends from the west side of the Polishing Pond to the east side of Ash Lagoon No. 2. Isolated ground- water mounds have developed within the area of the oxidized ground-water mound. Piezometers located in the oxidized till suggest limited leachate activity. No seepage activity is evident in the unoxidized till. 27 The greatest changes in chloride and boron concentrations within the oxidized till have occurred where piezometric levels have changed the most. Although increasing water levels do not automatically suggest that the water affecting the piezometers is leachate, changing piezometric levels do suggest ground-water movement. Oxidized till piezometers C868B and C869B located in the middle of the lagoons, between Ash Lagoon No. 1 and No. 2, have shown increased piezometric levels but chemical information does not indicate leachate influence. On the west side of the Polishing Pond, the boron levels have changed only slightly in the oxidized till piezometers C728A and C728D, where the chloride levels have changed more significantly. The chloride level for C728A has decreased fi^om 403 mg/L in 1983 to 197 mg/L in 2003. The chloride level for C728D has increased from 185 mg/L in 1983 to 342 mg/L in 2003. Although these piezometers are close in proximity and installed at the same level, they are being influenced by different water. Chloride results for C728A suggest initial seepage and it is to be expected that over time the same observation will be seen in C728D. The piezometric surface of the Empress Gravel indicates a regional flow from northwest to southeast below Morrison Dam. As a general observation, Empress piezometers respond to changing reservoir levels. Results for the Empress layer do not indicate seepage activity with the majority of the analyses showing little real change in boron or chloride results. Sand lens piezometers C712B, C766 and C767 are located between the Polishing Pond and the cooling water canal. C767 is located on the top of dyke G and C766 and C712B are located at the toe of dyke G. These piezometers have historically been of interest as the sand lens provides a preferential pathway for leachate migration of boron concentrations. C766 shows an increasing trend up to October 1988 with a peak of 43.0 mg/L in April 1995. Since 1995 the boron levels have declined modestly and have remained between 25 and 38 mg/L. Up to April 1988 the boron concentration for C767 was increasing and peaked at 49.4 mg/L. Since this peak the boron concentration steadily decreased to the end of 1991 where it leveled off near 5 mg/L and has since remained with one exception, a concentration of 1 1 .7 mg/L in October 2000. Piezometer C712B has been monitored for several years. Historically, boron levels were below 1 mg/L. From 1992 to 2003, boron levels have remained relatively steady around between 12 and 20 mg/L. 28 3.3.3.2 Montana Samples were collected from monitoring wells 7, 16, and 24 during 2003. Well 7 is completed in Hart Coal, well 16 is completed in the Fort Union Formation, and well 24 is completed in alluvium. The TDS concentration in water from all three monitoring wells decreased in 2003. Changes in TDS with time for wells 7, 16, and 24 are shown in Figure 3.15. Total Dissolved Solids S 650 -GWQQC 16 -GWQQC 24 -GWQQC 7 Figure 3.15 Total Dissolved Solids in Samples from Montana Wells. 29 3.4 Cookson Reservoir 3.4.1 Storage On January 1, 2003, Cookson Reservoir storage was 31,320 dam' or 72% of the full supply volume. The 2003 maximum, minimum, and period elevations and volumes are shown in Table 3.5. Inflows into the reservoir were near normal in 2003. A release was initiated in May to meet the recommended Poplar River basin demand release for the 2002-2003 apportionment years. No releases were required to maintain the recommended apportionment target flow at the International Boundary for the remainder of the year. In addition to runoff, reservoir levels were augmented by ground-water pumping. Wells in the abandoned west block mine site supplied 4,489 dam' to Girard Creek. It is estimated that approximately 70% of this flow volume reached Cookson Reservoir. Wells in the soil salinity project area supplied 426daml Table 3.5 Cookson Reservoir Storage Statistics for 2003 Date Elevation (m) Contents (dam') January 1 751.31 31,320 May 1 7 (Maximum) 752.28 37,990 October 27 (Minimum) 751.11 30,770 December 3 1 751.26 31,010 Full Supply Level 753.00 43,410 30 The Poplar River Power Station is dependent on water from Cookson Reservoir for cooling. Power plant operation is not adversely affected until reservoir levels drop below 749.0 metres. The dead storage level for cooling water used in the generation process is 745.0 metres. The 2003 recorded levels and associated operating levels are shown in Figure 3.16. 2003 Cookson Reservoir Daily Mean water Levels Full Supply Level -Ten Year Median Level Minimum Desired Operating Level Minimum Useable Storage Level ...1 _.^. Figure 3.16 Cookson Reservoir Daily Mean Water Levels for 2003 and Median ' Daily Water Levels, 1993-2002 31 3.4.2 Water Quality The period from 1987 to 1993 saw very low volumes of surface-water runoff to Cookson Reservoir. Consequently, total dissolved solids (TDS) in the reservoir increased steadily from approximately 780 mg/L to over 1,800 mg/L. Since 1993, higher runoff volumes have improved reservoir water quality. Since 1997, the TDS levels in the reservoir have generally remained below 1,000 mg/L. The average TDS level in Cookson Reservoir in 2003 was 928 mg/L, up slightly from the 2002 average level of 910 mg/L but still below past levels. 3.5 Air Quality SaskPower's ambient SO2 monitoring for 2003 recorded no values greater than Saskatchewan Environment's one-hour average standard of 0.17 ppm and the 24-hour average standard of 0.06 ppm. The ambient SO2 monitor was replaced in January 2001 which has greatly improved the availability of this information. The 2003 geometric mean for the high- volume suspended-particulate sampler was 17.6 |ag/m^ and 2003 was the twelfth consecutive year of below-average particulate readings. One total suspended-particulate concentration exceeded the Saskatchewan provincial standard of 120 ^g/m^/24 hours in 2003. This occurred when a reading of 187.4 ng/m^/24 hours was taken on October 24, 2003. 3.6 Quality Control 3.6.1 Streamflow Current-meter discharge measurements were made at the East Poplar River at International Boundary site on August 6, 2003 by personnel from the U.S. Geological Survey (USGS) and Environment Canada (EC) to confirm sfreamflow measurement comparability. Data from the two current-meter discharge measurements are shown in Table 3.6. The measured discharges compared well with each other and the theoretical discharge computation of 0.053 m^/s for a 90° V-notch weir. 32 Table 3.6 Streamflow Measurement Results for August 6, 2003 Agency Time CST Width (m) - ■"■■■ r-=i^ Mean Area (m') Velocity (m/s) Gauge Height (m) Discharge (m^/s) EC 1030 1.3 0.140 0.346 1.579 0.049 USGS 1030 1.2 0.131 0.405 1.579 0.053 3.6.2 Water Quality Quality-control sampling was carried out at the East Poplar River at International Boundary on September 9, 2003. Participating agencies included the U.S. Geological Survey, Environment Canada, and SaskPower. Sets of triplicate samples were split from USGS sampling chums and submitted to the respective agency laboratories for analyses. Field procedures were identical to those used since 1986. 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