WATER QUALITY

IN THE

POPLAR RIVER BASIN

International Joint Commission January 1981 Table of Contents Chapter Page

LIST OF FIGURES V LIST OF TABLES vii

SUMMARY X

I INTRODUCTION 1 Events Leading to the Reference 1 Scope of the Inquiry 4 Unilateral Actions Occurring Beforeand During the 7 Course of the Inquiry Bilateral Actions OccurringDuring the 8 Course of the Inquiry Commission and Board Activities During the Course 8 of the Study

I1 THE POPLAR RIVER BASIN 12 Surface Water Quantity and Quality 12 Groundwater Quantity and Quality 17 Aquatic Biologic Resources 21

I11 THE SPC PROJECT 22 22 23 24 The Power Plant 25 Ash Disposal System - The Original and 26 Current Designs Factors Affecting PoplarRiver Water Quality 28 Atmospheric Emissions 34 Cooling Water System 35 Cookson Reservoir 36 Natural Inflow to CooksonReservoir 36 Evaporation from Cookson Reservoir 37 Seepage from Cookson Reservoir 38 IVTHE BOARD'S INVESTIGATION 39 Surface Water Quality 40 Groundwater Quantity and Quality 41 Biological Resources 43 Uses and Water Quality Objectives 43 Plant, Mine and Reservoir Operations 45 Supplementary Report onthe Current Ash 46 Disposal System Summary of Effects 46 V PUBLICHEARINGS 52 Public Hearings on the Reference to the 53 Commission The September 1979 Hearings 55 The October 1979 Hearings 70 Supplementary Submissions 79

VI THE COMMISSION'SCONSIDERATIONS AND CONCLUSIONS 80 Baseline Water Quality 80 Measured Surface Water Quality 81 Total Dissolved Solidsand Boron in 89 the Poplar River System Groundwater 109 Existing and Reasonably Foreseeable Uses 112 Existing Uses 112 Reasonably Foreseeable Uses 116 Water Quality Requirements for Uses in the 125 Poplar River Basin Toxicity of Boron in Irrigation Water 127 Toxicity of TDS in Irrigation Water 137 Impacts of Water Uses, Apportionment and the 142 SPC Project on the Poplar River System Impacts of Cookson Reservoir on 144 Water Quality Predicted Impacts of Water Uses in the 148 Un i ted States Predicted Impacts of Water Apportionment 150 Impacts on Water Quality 150 Impacts on Biological Resources 156 Predicted Impacts of Cookson Reservoir 158 and the SPC Power Project Impacts on Water Quality 158 Impacts on Barley and Alfalfa Crops 173 Impact on Barley and Alfalfa Production 176 Other Considerations 181 Multipurpose Water Quality Objectives 181 Air Quality Aspects 186 Prior Notice and Consultation 188 Simultaneous Considerations of Water 188 Quality and Water Quantity PROPOSED COURSE OF ACTION 190 LIST OF APPENDICES A Text of Reference 210 B Directive to the International Poplar River 213 Water Quality Board C Membership of the International PoplarRiver 220 Water Quality Board D Membership of the Technical Committees 221 E Participating Organizations 223 F Correspondence between the Commission, the 224 Board and the Governments G Persons Presenting Briefs or Testimony at IJC 232 Public Hearings H Selected Boron References 236 I Additional Computer Runs 240 J The Helsinki Rules 26 5 - iv - List of Figures Title Page 11-1 PoplarRiver Basin 13 11-2 SchematicDiagram of GeologicFormations and 19 Groundwater Flows IV-1 Comparison of PredictedBoron and TDS 48 Concentrations for Original and Current Ash Disposal Systems East Fork at International Boundary IV-2 Comparison of PredictedBoron and TDS 49 Concentrations for Original and Current Ash Disposal Systems East Fork Near Scobey IV- 3Comparison of PredictedBoron and TDS sd Concentrations for Original and Current Ash Disposal Systems Poplar River Near Scobey IV-4 Comparison of Predicted Boron and TDS 51 Concentrations for Original and Current Ash Disposal Systems Poplar RiverNear Poplar VI-1 Schematic Diagram of Poplar River Basin and 82 Water Quality Sampling Stations

VI-2 Model Predictions for TDS Concentrations in 95 the East Fork at the International Boundary Before Morrison Dam (x) Compared to Observed Historical Median Monthly Values(.) VI-3 Model Predictions for TDS Concentrations in 95 the Poplar River Near Poplar, Montana Before Morrison Dam (x) Compared with Observed Historical Median Monthly Values(.) VI-4 Model Predictions for TDS Concentrations (x) 96 in the East Fork at the International Boundary Compared with Observed Values(.) VI-5 Model Predictions for TDS Concentrations (x) 96 in the Poplar River Near Poplar, Montana Compared with Observed Values (.) VI-6 Comparison of Model Predicted Boronand TDS 97 Concentrations with Concentrations Measured Between 1975 and 1980 in the East Fork at International Boundary -v-

VI-7 Comparison of Model Predicted Boronand TDS 98 Concentrations with Concentrations Measured Between 1975 and 1980 in the East Fork Near Scobey VI-8 Comparison of Model Predicted Boron and TDS 99 concentrations with Concentrations Measured Between 1975 and 1980in the Poplar River Below Scobey VI-9 Comparison of Model Predicted Boron and TDS 100 Concentrations with Concentrations Measured Between 1975 and 1980in the Poplar River Near Poplar VI-10 Comparison of Model Predicted Boron and TDS 101 Concentrations with Concentrations Measured Between 1975 and 1980 in the Middle Forkat International Boundary VI-11 Comparison of Model Predicted Boron and TDS 102 Concentrations with Concentrations Measured Between 1975 and 1980in the Middle Fork Above Scobey VI-1 2 Comparison of Model Predicted Boron and TDS 103 Concentrations with Concentrations Measured Between 1975 and 1980in the West Forkat International Boundary VI-13 Comparison of Model Predicted Boron and TDS 104 Concentrations with Concentrations Measured Between 1975 and 1980 in the West Fork Near Bredette VI-14 Generalized Vertical Variation in Selected 111 Chemical Constituents in Geologic Formations

VI-15 Measured Boron and TDS Concentrations 146 6r (Cookson Reservoir and East Fork at Boundary) 147 and Monthly Mean Flows (Eastand Middle Forks at Boundary) Between 1975 and 1980 VI-16 Schematic Summary of Model Components Used to 160 Assess the Impactof the Poplar River Project on Water Quality VI-17 predicted Effect of SPC Plant and Cookson 167 Reservoir on Mean Boronand TDS Concentrations in the East Fork at International Boundary - vi -

VI-18 Predicted Effect of SPC Plant and Cookson 168 Reservoir on Mean Boron and TDS Concentrations in the East Fork Near Scobey VI-19 PredictedEffect of SPCPlant and Cookson 169 Reservoir on Mean Boronand TDS Concentrations in the Poplar River Below Scobey VI-20 PredictedEffect of SPCPlant and Cookson170 Reservoir on Mean Boronand TDS Concentrations in the Poplar River Near Poplar VI-21 PredictedRelationship Between Crop Loss for 179 Barley Grown Along East Forkand Mean Boron Concentrations in East Fork at International Boundary VI-22 Predicted Relationship Between CropLoss for 180 Barley Grown Between Confluenceof East and Middle Forks and Fort Peck Indian Reservation and Mean Boron Concentrations in East Fork at International Boundary - vii -

List of Tables "." Title Page 11-1Long-Term Flows at the International Boundary 14 11-2 Geologic Formations in tile PoplarRiver Basin 18

11-3 Estimated Hydrologic Characteristics of 20 Generalized Aquifer Layers of Upper Poplar River Basin, Saskatchewan and Montana

VI-1Measured TDS, Boron, SAR and Flows inthe East Fork 84 at the International Boundary Prior to the Closure of Morrison Dam

VI-2 Measured Concentrations (mg/l) of Major Ions in the 86 East Fork at the International Boundary Prior to the ?losure of Morrison Dam VI-3 Measured Values for Nutrients (mg/l), Oxygen (mg/l) , 87 pH and Temperature in the East Fork at the International Boundary Prior to the Closure of Morrison Dam VI-4 Measured Concentrations (mg/l) of Metals in the East 88 Fork at the International Boundary Prior to the Closure of Morrison Dam

VI-5 Boron and TDS Concentrations in Nine East-Central 90 Montana Streams, October 1975-October 1977 VI-6 Computed Pre-Development and Historic Baseline 91 (1975) TDS Concentrations for Selected Sites in the Poplar River Basin VI-7 Computed Pre-Development and Historic Baseline (1975) 92 Boron Concentrations €or Selected Sites in the Poplar River Basin VI-aaExisting Consumptive Water Uses in thePoplar River 114 Basin (cubic decametres) vI-abExisting Consumptive Water Uses inthe Poplar River 115 Basin (acre-feet) VI--9aTotal Projected Future Water Uses in the Poplar 117 River Basin: Saskatchewan (cubic decametres) - viii -

VI-9b Total Projected Future Water Uses in the Poplar 118 River Basin: Saskatchewan (acre-feet) VI-loa TotalProjected Future Irrigation in Montana, 121 Exclusive of the Fort Peck Indian Reservation (1985 and 2000) (cubic decametres) VI-lob Total Projected Future Irrigation in Montana, 122 Exclusive of the Fort Peck Indian Reservation (1985 and 2000) (acre-feet) VI-lla Total Projected Future Uses in the Poplar River 123 Basin Fort Peck Indian Reservation (cubic decametres)

VI-llb Total Projected Future Uses in the Poplar River 123 Basin Fort Peck Indian Reservation (acre-feet) VI-12 The Effect of Boron Concentrations on the Yield 129 of Selected Plant Species (expressed as dry weight (gm) per treatment) VI-13 AverageRelative Concentration Factors for Soil 130 Water Compared to Irrigation Water VI-14 Critical Boron Concentrations (mg/l) for Various 131 Crops VI-15 Predicted PercentReduction in Barley Yields 132 for Several Boron Concentrationsin the East Fork at the International Boundary VI-16 Effects of Boron on Barley Yields (expressed as 135 barley kernels (gm) per pot) at Several Soil pH Levels VI-17 Maximum Long-Term Boron Concentrations in 136 Irrigation Water for Full Protection of Selected Crops VI-18 Effect of TDS on CropProduction 138 VI-19 Percentage Yield Reduction of Alfalfa at Three TDS 138 Concentrations for Various Leaching Fractions

VI-20 Alfalfa Yield Reductions for Several TDS 139 Concentrations and Leaching Fractions VI-21 Maximum Long-Term TDS Concentration in Irrigation 142 Water for Full Protection of Selectec Crops - ix -

VI-22 predicted Effect of Apportionment on Mean Boron 152 and TDS Concentrations: East Fork at International Boundary VI-23 Predicted Effect of Apportionment on Mean Boron 152 and TDS Concentrations: East Fork Above Scobey VI-24 Predicted Effect of Apportionment on Mean Boron 153 and TDS Concentrations: Middle Fork at International Boundary VI-25 Predicted Effect of Apportionment on Mean Boron 153 and TDS Concentrations: Middle Fork Above Confluence with East Fork VI-26 Predicted Effect of Apportionment on Mean Boron 154 and TDS Concentrations: West Fork at International Boundary VI-27 Predicted Effect of Apportionment on Mean Boron 154 and TDS Concentrations: West Fork Near Bredette VI-28 Predicted Effect of Various Ash Lagoon Seepage 165 Rates on Mean Boronand TDS Concentrations in the East Fork at the International Boundary

VI-29 A Comparison of the Board's Recommended Multi- 183 Purpose Water Quality Objectivesfor the East Fork at the International Boundary with Median Measured Values, Saskatchewan Criteriaand Montana Objectives -x-

SUMMARY

This report of the International Joint Commission concerning water quality in the Poplar River Basinhas been prepared under a Reference from the Governments of the United Statesand Canada dated August 2, 1977. It continues the Commission's involvement in water related issues in the Poplar River Basin which began with a consideration of water apportionment under a previous Reference. The 1977 Reference requested the Commission to examine into and report upon the water quality of the Poplar River, including the transboundary water quality implicationsof the Saskatchewan Power Corporation's thermal power stationnear Coronach, Saskatchewan, and to make recommendations which would assist Governments in ensuring that the provisions of Article IVof the Boundary Waters Treatyof 1909 are honored. The pertinent provision of Article IV states that "It is further agreed that the waters herein defined as boundary watersand waters flowing across the boundary shallnot be polluted on either side to the injuryof health or property on theother."

The Commission has viewed this Referencefrom two perspectives: first, a continuation and expansion of the Commission's study of water apportionment in the Poplar River Basin and second, a consideration of whether any measures are required to ensure that the provisions of Article IVof the Boundary Waters Treaty are honored. These two perspectives are related in this case and raise issues regarding both the obligations of one countryto the other and the legitimate expectations of individuals in both countries. They also raise issues regarding the relationship between emerging principles of international law, such as equitable - xi -

apportionment, and the mutual obligations of Canada and the United States embodied in the Boundary Waters Treaty of 1909.

The report briefly describes the physical setting of the Basin, including surface and groundwater quantity and quality and aquatic biological resources. The report also describes the development of the SPC power project, including the significant changes that were made to the ash handling system and the investigations of the International Poplar River Water Quality Board. It also includes a summaryof the testimony received at the public hearings.

The Commission found the fact-finding portion of this Reference extremely difficult for a number of reasons. For example, there had been very few water quality measurements taken in the Basin prior to the current study. In addition, constructionof facilities related to the SPC project began before the Reference was received. Consequently, an adequate, measured baseline against which to assess impacts of the apportionment and the SPC project was not available. However, the Commission did compare the mathematical model predictions used by the Board with other measured values throughout the Basin and concluded that the model does provide reasonable estimates of historic baseline water quality. This water quality was found to be relatively poor, particularly with respect to boron and to a lesser extent total dissolved solids (TDS) .

Information with respect to existing uses was also incomplete. It is clear that uses in Canada have been slight and that the most significant use in the United States is for irrigation purposes. While it is known that alfalfa is the predominant crop and that other crops such as wheatand barley have been irrigated to a much lesser degree, the precise location and amount of each is - xii - generally not known. For example, alfalfa is the only crop known to have been irrigated along the East Fork. As in the apportionment study, the Commission found that there are reasonably foreseeable uses for all of the water in the Basin. It is clear that in Saskatchewan, most of these uses are associated with the SPC power project, and in Montana, most are associated with irrigation. Again, it is not clear how much of each crop will be irrigated in each portion of the Basin in the future.

A determination of the water quality requirements of uses in the Montana portion of the Basin has also been difficult. This has been particularly true of the boron and TDS requirements of specific crops that may be irrigated. In large part, thishas been due to the many site specific conditionsthat may significantly affect whether or not a certain levelof boron or TDS will limit crop yields. In addition, there have apparently been no surveys in the Basin to assess whether or not the current levels of boron and TDS in irrigation water from the Poplar River are adversely affecting crops currentlyirrigated. The Commission has relied heavily on the judgment of its Poplar River Water Quality Board in its evaluation of the toxicity of irrigation water to commercial crops e

In large part due to the factors noted above, a determination of the likely impacts of the apportionment and the SPC project was also difficult. The Commission has accepted the model predictions of the Board for its estimates of likely water quality impacts. The Commission emphasizes, however,that due to the many uncertainties discussed above md elsewhere in this report, future water quality may actually be either better or worse than that which is projected. The Commission believes that there will be some adverse water quality impacts downstreamand while the precise amount cannot now be determined, it is not believed that they will be substantial. - xiii -

The Commission has examined the potential transboundary water quality effects of the altered transboundary flows calledfor in the recommended apportionmentand of the SPC power project with the above considerations in mind. The Commission recognizes that there will likelybe some adverse effects from changesin water quality and quantity. For example, the reduction inthe amount of water crossing the boundary is expected to adversely affect the maintenance of the existing biological communityin the East Fork of the Poplar River. The Commission considers this an adverse effect of water quantity reductions and, therefore, doesnot propose measures to ensure compliance with ArticleIV because it does not fall within Article IV. However, because this effect was not known and, therefore, not consideredby the Commission inits 1978 Apportionment Report, it now believes that this effect should be considered by Governments. Other water quantity considerations both beneficial and adverse which mayneed to be similarly addressed are in part suggested by the apportionment report,e.g., (1) new information regarding the effects of the project, (2) effects of possible future reservoirs, (3) the feasibility of Canada using its apportioned share of water, (4) the results of plans of mutual advantage, and (5) differences between actualand projected flows.

In addition, the projectedincreased boron concentration will likely causea small reduction in yields of irrigated crops such as barley and wheat on the relatively limited acreageon which these crops are nowirrigated. The Board reported that in 1978 it was known that there were 45 acres of barley irrigated immediately below the confluence of the East and Middle Forks. It is not certain how many acres overthe years may have been similarly irrigated in areas that mightbe affected by the SPC project. However, at the public hearings held, pursuantto this Reference, no others were identified. Therefore, it may be assumed that only a very small acreage is involved. A somewhat larger impact would be expected on barleyand wheat yields if they were to be irrigated - xiv - along the East Fork of the Poplar River where none is known to have been irrigated. It is not known, therefore, that these are presently feasible crops in this area for irrigation. No adverse impact on alfalfa yields are expected. In addition, the Commission believes that the typesand range of reasonably foreseeable uses in Montana identified in Chapter VI of this report are expected to remain substantially unchanged. Figures VI-21 and VI-22 in Chapter VI indicate the approximate dollar losses that are predicted to occur as a consequence of the effects of increased boron concentrations on the yield of barley. Such losses, whenconsidered in conjunction with the boron concentrations predicted to occur and the limited number of acres likely to be involved, may be described as minor.

With the above findings in mind and noting the uncertainties involved in assessing present and future impacts, the Commission believes it is possible to ensure that the provisions of Article IV of the Boundary Waters Treaty continueto be honored in the Poplar River Basin without delaying the operation of the plant. Measures to accomplish this are included in the Proposed Course of Action set forth below. At this point, the Commission wishes to noke that it did consider the possibility of recommending that the second unit of the SPC power project not be operated until after the impacts of the first unit were better known. However, based upon the available information the Commission now concludes that there are no compelling reasons to expect that the SPC project impacts on either water quality or traditional uses warrant delaying the operation of the second unit. Thus, considering the above uncertainties, the small extent of the estimated impacts on downstream users in relation to the Basin as a whole, the actions taken and commitments made in Canada to minimize the effects, the importance and public benefits of the SPC project, the proposed division of the transboundary flows, and the course of action hereinafter recommended, the Commission concludes that the - xv - apportionment recommended in 1978 remains equitableand should be adopted by the United States and Canada and that ArticleIV of the Treaty will not be violated in so doing. The Commission notes that this conclusion with regard to the apportionmentis based upon available information and suggests that the matters referred to above and discussed in this report be considered by Governments in their discussions on the apportionment question.

Finally, the Commission concludes that the most appropriate course of action for the Governments to take in this caseto ensure that Article Iv is not violated is one which includes anumber of interrelated provisions. ~t is essential that this course of action include water quality objectives designedto protect water users downstream, measures to help resolve the many uncertainties associated with existing and future water quality as well as the water quality requirements of downstreamuses, and provision for additional mitigation should thatbe found necessary. In addition, it is essential that adequate provision be madefor assisting, and where appropriate compensating, those who maybe adversely affected by the new regime. The Commission believes that implementationof these provisions will fully satisfy the mutual obligations set forth in Article IV of the Boundary Waters Treatyand will assist in assuring that the apportionment recommended in 1978 remains equitable to both countries. The Commission believes that the following course of action contains these essential provisionsand recommends that it be adopted by the Governments of the United States and Canada.

1. A mechanism should be qstablished at this time to provide an appropriate forum within which existing usersof water in Montana who may be adversely affected can seek compensation for losses believed to be attributable to the construction and operation of the SPC power plant and its ancillary facilities. The preferred mechanism would be a bi-national claims commission. - xvi -

2. Additional measures should be undertaken to ensure that the provisions of Articles IV of the Boundary Waters Treaty are honored if it is determined by Governments, based upon new information, that changes in water quality attributable to the SPC plantand its ancillary facilities haveor are likely to have greater impacts than those envisaged in this report.

3. The following interim boron and TDS objectives should be adopted by the Governments of the United Statesand Canada:

a) For boron during the March to October period, the long-term average of the flow-weighted concentrations should be2.5 mg/l or less in the East Fork of the Poplar Riverat the International Boundary, witha maximum flow-weighted concentration not to exceed 3.5 mg/l for any three consecutive months during this period;and

b) For TDS during the March to October period, thelong-term average of the flow-weighted concentrations shouldbe 1000 mg/l or less in the East Fork of the Poplar River at the International Boundary, with a maximum flow-weighted concentration not to exceed 1500 mg/l for any three consecutive months during this period.

4. A bilateral group, constituted as a Board of the IJC or as a group reporting directlyto the Governments of the United States and Canada, should be maintained to monitor water qualityand water quantity in the Basin with particular reference to the impactsof the SPC project; clarify to the extent necessary the effectsof water quality and water quantity on water uses; and review and recommend water quality objectives as appropriate. - xvii -

5. The appropriategovernmental agencies in the United States should as a priority matter provide technical adviceand other appropriate assistance to those in Montana who believe they might be adversely affected by changes resulting from the apportionmentand the SPC project to assist them in adjusting to the newregime.

-1-

CHAPTER I

INTRODUCTION

On August 2, 1977, the Governments of the United States and Canada, pursuant to Article IX of the Boundary Waters Treaty of 1909, referred the matter of water quality in the Poplar River Basin to the Commission. The Reference specifically requested the Commission to examine into and report upon the water quality of the Poplar River, including the transboundary water quality implications of the thermal power station of the Saskatchewan Power Corporation and its ancillary facilities, including coal mining at a site near Coronach, Saskatchewan, and to make recommendations whichwould assist Governments in ensuring that the provision of Article IV of the Boundary Waters Treaty of 1909 are honored. This Reference continued the Commission's involvement with water related issues in the Poplar River Basin which began with a consideration of water apportionment under a previous Reference. The full text of the Reference is found in Appendix A.

EVENTS LEADING TOTHE REFERENCE

In March 1972 the Saskatchewan Power Corporation (SPC) applied to the Province of Saskatchewan for permission to store and use waters from the East Fork. In July 1972 in response to this request the Province reserved 7400 dam3 (6,000 acre-feet) of water annually for a period of five years for this purpose. On September 4, 1974, SPC announced plans for the construction of a coal-fired thermal. electric generating stationincluding a reservoir on the East Fork and a new lignite coal mine at Coronach, Saskatchewan near the International Boundary. The IJC, through its International Souris-Red Rivers Engineering Board, was advised of the proposal shortly thereafter. -2-

The Commission advised the Governments of the United States and Canada on February 20, 1975 that it had asked its International Souris-Red Rivers Engineering Boardto review the proposal in light of a 1948 Reference dealing withwater apportionment and that it had asked its International Air Pollution Advisory Board to review the proposal under a separate 1966 Reference which asked the Commission to advise Governments of pollution problemsin boundary areas. The Commission also advised Governments that the proposed project might affect adversely the quality of Poplar River water crossing the 1nternat:ional Boundary and suggested thatthe Governments review the matter in light of the provisions of Article IV of the Boundary Waters Treaty relatingto water pollution.

The Saskatchewan Power Corporation, on February21, 1975, was issued an Authorization to ConstructWorks for Morrison Dam and the first unit ofa power plant under the Saskatchewan Water Rights Act, subject to conditionsimposed by the Boundary Waters Treatyof 1909 and the International River Improvements Act of Canada. The Government of Canada subsequently granteda five-year license on April 29, 1975, under the International River Improvements Act, to the Saskatchewan Power Corporation authorizing construction of the dam and reservoir on the East Fork subject to certain conditions including compliance with any future agreed apportionment andthe Boundary Waters Treaty,and monitoring by the SPC of water quality and quantity. This license was renewed on April 29, 1980, for a period of 35 years.

Although several studies were undertaken within Saskatchewan prior to 1975 regardingthe possible impacts of the proposed project, considerable concern arosein the United States regarding the potential transboundary effects. The matters of concern related to water quantity, water quality and air quality. These matters wereraised in early 1975 in a diplomatic note from the Government of the United States to the Government of Canada. In -3- that note the U.S. Government stated that construction ofthe proposed project might beginprior to completion of environmental studies and without an adequate assessment of impacts on the United States. The United States Government requested anearly meeting to review the project. Diplomatic exchanges continued from that time to the present. These are discussed briefly later in this section of the report.

In April 1975 the Poplar River Task Force of the International Souris-Red Rivers Engineering Boardwas formed to investigate the apportionment question pursuant theto above-noted 1948 Reference. The Commission's report on the appottionment was submitted to Governmentsin April 1978 based upon the report of the International Souris-Red Rivers Engineering Board and the testimony at public hearingsheld in the Basin. In that report the Commission recommended that the transboundary flows of the Poplar Riverbe divided equally betweenthe United States and Canada in accordance with a prescribed apportionment formula. The Commission also recommended that after the then ongoing water quality studies were completed, the apportionment be reviewed to determine whether any adjustments would be required. No formal response from Governments on this recommendation has yet been received by the Commission. The U.S. Government has advised the Commission that an Environmental Impact Statement would be required under the National Environmental Protection Act of 1969 before it would be in a position to acton the Commission's recommendations.

The Commission's InternationalAir Pollution Advisory Board, by memorandum dated August 21, 1975, advised that someair pollution problems would likely result from the project as it was then proposed. This information was later provided toGovernments. Since early 1975, the Governments havebeen discussing bilaterally the issue of air quality. -4-

There were severalrequests by Montana at the Commission's apportionmenthearings and elsewherethat the question of transboundarywater quality impacts of the project be referredto the Commission. This matter, however, was dealt with solelythrough bilateraldiscussions until August 2, 1977, when the current Reference was givento the Commission by the Governmentsof the United States and Canada pursuantto Article IX of the Boundary WatersTreaty of 1909.

SCOPE 0.F THE INQUIRY

As notedabove, the Reference requests the Commission to examine into and report upon the water quality of thePoplar River, includingthe transboundary water quality implications of the SPC power p:Lant at Coronach. Specifically, the Commission was asked to report upon thefollowing matters:

"1) The presentstate of waterquality, including fluctuations in water quality, with particular emphasis on thewaters of the EastPoplar River;

The factors,both natural and man-made, affectingexisting water quality, and their effects on wateruses:

The nature,location and significance of fisheries and wildlife dependent on the waters of the PoplarRiver;

The nature and location of existing and reasonablyforeseeable water uses; -5-

The effects on present water quality and consequent effects onthe uses identified in paragraphs (3) and (4) above, which would result from: (a) the changes in the flow regime of the Poplar River if apportionment of the waters of the Poplar River is made as recommended by the International sour is-Red Rivers Engineering Board 's Poplar River Task Force in its Report of February 6, 1976, or as the Commission may otherwise recommend; (b) the thermal power station of the Saskatchewan Power Corporation and ancillary facilities, including coal mining; and (c) implementation of other reasonably foreseeable developments;

Significant transboundary impacts of the Saskatchewan Power Corporation's thermal power station and ancillary facilities, including coal-mining, and of reasonably foreseeable developments in either country on the water quality and water level in the surrounding aquifers; and

Such other matters as the Commission may deem appropriate and relevant to water quality."

The Commission wasalso asked to "make recommendations which would assist Governments in ensuring that the provisions of -6-

Article IV of the Boundary Waters Treaty of 1909 are honored." Article IV states in relevant part that: "It is further agreed that the waters defined as boundary waters and waters flowing across the boundary shall not be polluted on either side to the injury of health or property on the other." Thus, the Commission must consider what water quality effects willlikely result in Montana from the proposed apportionment, the construction and operation of the plant or other reasonably foreseeable developments. If adverse effects are likely to occur, the Commission must consider whether these effects constitute injury within the meaning of the Treaty and, if so, whether measures can be taken to assure that such "in jury" does occur.not

In this regard the Commission notes that in its 1978 Report on Water Apportionment in the Poplar River Basin it was stated that once the water quality studies were underway, including the current study, the apportionment should be reviewed to determine whether any adjustments are required. The Commission considers that water quality is an essential element in determining whether or not an apportionment is equitable to both countries because the objective of equitable apportionment is to assure that each country has a reasonable and equitable share in the beneficial use of the water of an international drainage basin. Consequently, the Commission has viewed this reference to a significant extent as a continuationand expansion of its earlier apportionment study and has generally considered the Article IV obligation within the context of equitable apportionment taking into account the specific concerns of individuals who may be adversely affected.

The issue of potential air pollution resulting from the construction and operation of the SPC project has been raised at every public hearing held by the Commission since its initial involvement in the Poplar River issue. The current Reference, however, is limited to an assessment of the impact of the proposed -7-

SPC plant on water quality. The Commission has interpreted this to include a consideration of the impact of stack emissionson water quality in the Basin. Beyond this limited consideration the possible air quality impacts of the proposed project have notbeen investigated since that matterhas not been referred tothe Commi ss ion.

The Commission's inquiry has been complicatedby the fact that construction of portions ofthe SPC project began before the Reference was received. Construction of Morrison Dam began on July 22, 1975, and was completed by September 18, 1976, when the filling of Cookson Reservoir began. In addition, construction of the first unit of the power plant began in August 1975. As a result of these actions, the study site was permanently altered before the study under the Reference began. Consequently, an adequate measured baseline against which to assess impacts of the apportionment and the SPC project was not available. Approval to proceed with construction of the second unit was granted by the Government of Saskatchewan on November 14, 1979.

During 1979, SPC made substantial changes tothe original design of the ash disposal systemdue, in part, to the preliminary findings of the Commission's International PoplarRiver Water Quality Board, established to advise the Commissionon the Reference questions. The original and current ash disposal systems are described in Chapter 111 of this report.

In July 1980, the United States Environmental Protection Agency issued, and requested comments on, a Draft Environmental Impact Statement entitled "Impact of CanadianPower Plant Development and Flow Apportionment on the Poplar River Basin". Based upon a review of this draft report,the Commission finds no reason to change any of the conclusions and recommendations of this report. -8-

BILATERAL ACTIONS OCCURRING DURINGTHE COURSEOF THE INQUIRY

Several exchanges of diplomatic notes and bilateral discussions took place between the Governments of the United States and Canada during the study period. Montana and Saskatchewan officials also participated in many of these discussions. The discussions focused on the water quality impacts of the SPC plant (the samematter as covered by the present Reference) and air quality considerations. These discussions considered information provided in reports of the Commission and its International Poplar River Water Quality Board as well as reports developed unilaterally and not then being assessed by the Board. At the Commission's public hearing in Scobey on September 10, 1979, a spokesman representing the United States Department of State stated that these discussions did not prejudge the issues referred to the Commission.

On March 7, 1980, the Governments of the United States and Canada announced their intention to have a cooperativemonitoring program. on air and water quality matters in place by the time the first unit becomes operational. Subsequently, agreement was reached and on September 23, 1980 the Governments announced the technical monitoring schedules for the Poplar River cooperative monitoring arrangement .

COMMISSION AND BOARD ACTIVITIES DURING THE COURSEOF THE STUDY

The current Reference was received on August 2, 1977. The Commission established the International Poplar River Water Quality Board (the Board) on September ?8, 1977 and issued a Directive to the Board requesting that the Board undertake the necessary studies and investigations in order to advise the Commission on all matters relevant to the Reference questions. The Board was also asked by the Commission to advise on mitigation measureswhich could be taken to avoid or relieve any adverse transboundary effects andto -9- indicate approximate costs of such measures. As a matter of priority the Board was requested to immediately advisethe Commission on the status of the project and the effects of continued project development on the Board's ability to conduct itsstudy. A copy of the Directive is in Appendix B.

The Board consisted offour Canadian and four United States members drawn from federal, provincial and state agencies. Board members were advisedby the Commission that they and any Committee members appointed were to serve in a personal and professional capacity and notas representatives of their particular employers. A list of the Board membersis included in Appendix C.

Following the Commission's preliminary hearingson the Reference in Scobey, Montana and Regina, Saskatchewan, on November 2 and 3, 1977, the Board identified six main areasof study and formed five Committeesto address them including surface water quality, water uses and water quality objectives, biological resources, groundwater quantityand quality, and plant, mine and reservoir operations. The membership of each Committee is listed in Appendix D and participating agencies are identifiedin Appendix E.

The Board's planof study was forwarded tothe Commission in January 1978 and received final approval in February 1978. In the plan of studyand in preparing the Board Report, theneed for close cooperation and communication was recognized. This was achieved in part through periodic workshopsinvolving Committees and the Board, and through development of Committee reports compatible with the Board Report. Despite predictions of anearly completion date for the study, problems in obtaining baseline dataand other delays eventually lead to the Board's Report being received by the Commission in July 1979. - 10 -

In its meetings with the Board on January 19, 1978, to consider and approvethe plan of study, the Commission discussedthe request in theDirective for the Board toreport on the need for a moratorium on theconstruction of thePoplar River power plant and ancillaryfacilities. At thatmeeting, the Board advisedthe Commissionof difficulties it had encountered in obtaining sufficientdata regarding the proposed project. By letterdated January 27, 1978, the Commission advisedthe Governmentsof this matter. The Governmentsresponded on February 22, 1978, thatthe necessaryinformation should be availableto the Commission no later than March 15 and that if following an assessment of thatdata the Commissionhad concernsregarding its capacityto carry out the study, it should so advisethe Governments. In thatevent the Governments would cooperateto ensure that construction on other activities would notinterfere with thetimely collection of data consistent with the Commission's responsibilities under the Reference.

The Board reportedto the Commission onMarch 13, 1978 that it had receivedthe necessary data to assess this request and advisedthat construction plans by SPC, as understood by the Board at that time,contained no provisions which would prejudicethe collection of basicdata, wheregaps had been identified. On April 10, 1978, in a letterto Governments,the Commission concluded that "continued workon thePoplar River project should not materially and irrevocablyalter conditions in the study area beyond thatwhich may have alreadyoccurred before the Board will have an opportunityto assess the adequacy of theavailable data, and subjectto the above safeguards, is satisfiedthat workon the Project may proceed."

Duringthe conduct of the study the Commission was continuallykept informed of important developments from progress reports and throughliaison between Commission staff and the Board. - 11 -

Copies of relevant correspondence betweenthe Commission, the Board and Governments is contained in Appendix F.

By letter dated October20, 1978, the Commission advised the Governments that constructionand operations of the SPC project as then envisaged would likely result in unacceptably high boron levels and that it was not clear at that time whether adequate mitigation measures were possibleor practical. This subject was discussed in greater detail in the Commission's Interim Reportdated February 15, 1979. It is important to note at this point that following this report the ash handling system, an important component of the SPC plant design, was substantially changedand improved by SPC. These original and current designs are discussed further in Chapter 111 of this report.

During the study, the Board and Commission became increasingly concerned with theneed for continued monitoring of groundwater quality and quantity even after the Commission's study was completed in order that data for impact assessment would be available if the SPC project was to be completed and operated. The Commission recommended that thisbe done in a letter to Governments dated November 22, 1978.

Following receipt of the Board's Report in July 1979 further public hearings wereheld in the Basin to obtain comments from interested parties on the contents of that report. These hearings are summarizedin Chapter V. - 12 -

CHAPTER I I

THE POPLAR RIVER BASIN

The Poplar RiverBasin is located inthe semi-arid region of south-centralSaskatchewan and northeastern Montana. There are three sub-basinsof the Poplar River;the East, Middleand West Fork Basins.The East Fork of the Poplar River (called the East Poplar i.n Canada)joins the main stem Middle Fork Poplar River (called the Poplar Riverin Canada) in Montana about three km (two miles) north of Scobey,Montana. The West Fork of the Poplar River (called the West Poplar inCanada) joins the main stem 30 km (20 miles) south of Scobey. The main stem empties into the MissouriRiver near Poplar, Montanaabout 100 km (60 miles) south of theInternational Boundary.These three main tributaries receive water from a number of smaller secondary streams inMontana and Saskatchewan including Girard Creek, which lies whollyin Saskatchewan, Goose and Coal Creeks which cross theInternational Boundary, and Butte Creek located entirely in Montana(Figure 11-1). The total Basin area is 2 8620 k:n2 (3330 mi2) with 3150 km2 (1220 mi ) inCanada and 2 5470 km2 (2110 mi ) inthe United States, of which the lower 2 2230 km2 (860 mi ) lies within the Fort Peck Indian Reservation.Throughout this report designationsof the tributaries andsub-basins are as usedin the Commission's 1978 Report on Water Apportionment.

SURFACE WATER QUANTITY AND QUALITY

All three branches of the riverhave similar flow characteristics; a highspring flow caused bysnow-melt and spring rains,and lasting about 10 days to 3 weeks, whichrapidly decreases to a small flow during the summer, fall andwinter. At times this - 13 .-

LEGEND

SASKATCHEWAN

Asrlnlbeh

POPLAR RIVER BASIN

J Figure 11-1 Poplar River Basin - 14 -

flow may drop to zero at the InternationalBoundary. The peak spring flows account for approximatelythree-quarters of the total annualdischarge. The mean annual precipitation ranges from 30 to 40 cm (12 to 16in.), about a thirdof which is snow.The Basin is also characterizedby relatively low humidityand a veryhigh rate ofevaporation averaging more than0.76 metre (2.5ft) annually. 3 Themean annual natural flow at Poplar, Montana is 114,000dam (92,600ac-ft), with wide variations on a seasonalbasis and from year to year;the maximum andminimum annual flows being 411,000 darn3 (333,000 ac-ft) and17,800 dam3 (14,400 ac-ft) respectively.Approximately 40 percentof the total flowin the Basinoriginates in Saskatchewan. The long term averageannual, minimumand maximum annual natural flows at the three maincrossings of the Poplar Riverinto the United States are shownin Table 11-1 below.

Table 11-1 Long-TermFlows at theInternational Boundary

AverageMaximum Minimum Location Annual Annual Annual " (dam3)(ac-ft) ( dam3)(ac-f t) ( dam3)(ac-f t)

East Fork 46,80057,7002,6403,26012,500 15,400

Middle Fork 16,000 13,000 2,890 2,34054,20043,900

4 ,690 3,800 142 115 25,000 20,30025,000West 115 Fork 142 3,800 4,690

Thenatural drainage in the Basinhas been modified by the additionof numerous reservoirs, the largestbeing Cookson 3 Reservoir. This reservoir has a storagecapacity of 41,166 dam (33,375ac-ft), and was constructed by SPC to providecooling water for the power plant at Coronach. The remaining major reservoirs are 3 all in Saskatchewanand have a combinedcapacity of only 2270 dam (1840 ac-f t). - 15 -

Fife Lake is the most important of the internal drainage areas in the Basin which,during most years, do not contribute to the flow of the PoplarRiver System. The lake lies in the upper portion of the East Fork and is sufficiently large that natural evaporation usually depletes all therunoff so that in a normal year there is no outflow. During a series of dry yearsthe streamflow that reaches the lake evaporates and the mineral content ofthe lake becomes concentrated. In wet years,or in a series of moderately wet years, sufficientwater accumulates in the lake to raise the water level so that it spills to Girard Creekand subsequently into the East Fork. The spillwater is then very high in dissolved minerals.

In 1952 a project was constructed atthe outlet of the lake to provide stockwatering, flood control and to prevent blowing alkali from the lake bottom from damaging nearby crops. The project consists of an earthfillplaced across the natural overflow channel with an operating spillway (three gated culverts)and emergency spillway. Historically, overflow from Fife Lakehas occurred on average once every ten years. The wet years in 1974 and 1975 caused overflows in 1975 and 1976. In contrast the years 1977 and 1978 were dry years during which the water levels of Fife Lakereceded and no overflow occured. The return of high runoff in 1979 again raised the lake level and it overflowed in late May of 1979.

Fife Lake is presently used for minor stockwatering. There are no immediate future plansfor the lake becausea water rights licence has not been granted, pending resolution of outstanding complaints by local landowners.

Surface water quality in the Poplar River Basin varies seasonally and is strongly influenced by streamflow. The specific water quality conditions in the Poplar River Basin prior to the construction of the SPC project are discussedin detail in Chapter - 16 -

VI of this report. As a general statement, the water quality is similar to that observed in other semi-arid prairie basins in the United States and Canada, with onemajor characteristic being a relatively high concentration of dissolved minerals. During low flow periods total dissolved solids (TDS) in the Basin usually exceeded 1000 mg/l whereas during the snowmelt period in the spring, TDS levels were in the 600 to 800 mg/l range. The concentrations of TD.3 increased downstream with monthly median TDS values between 450 and 1200 mg/l at the International Boundary and in the 700 to 1500 mg/l range at Poplar, Montana. The lowest seasonal TDS values were during the spring, while autumnand winter median valuesranged from about 25 to 100 percent larger than the spring median concentrations.

Variations in concentrations of bicarbonate and sulphate vary seasonally throughout the Basin, similarto TDS. The highest nutrient concentrations (nitrogenand phosphorus), occurred during spring or summer when median seasonal total nitrogenand total phosphorus ranged from 1 to 2 mg/l and from 0.05 to 0.3 mg/l respectively.

Measured median concentrationsof boron averaged about2 mg/l in the East Fork at the International Boundary and about 1 mg/l elsewhere. Median concentrations of boron in the East Fork at the border have reached as high as 3 mg/l during high flow periodsas a result of overflows from Fife Lake. Downstream at Scobey and Poplar boron concentrations then decreased due to dilution by Middle and West Fork waters. Dissolved oxygen (DO) concentrations are generally above 4 mg/l with the autumn DO concentrations the highest (8.0 to 11.4 mg/l) and winter 30 concentrations the lowest (2.6 to 6.3 mg/l) at the East and West Forks at the border. Surface waters in the Basin are generally alkalinewith seasonal medianpH values ranging from 7.4 to 9.7, reflecting the alkaline nature of the soils. - 1.7 -

GROUNDWATER QUANTITY AND QUALITY-

Thegeologic characteristics and formations present in the PoplarRiver Basin are describedin detail in Appendix B ofthe Board's Report. Thegeneral character of thegeologic formations in thebasin are presentedin Table 11-2, and'she various layers presentedgraphically in Figure 11-2.

Thedeepest bedrock formation is the Bearpaw Formation, a thicksequence of marine silts andclays much less permeablethan theoverlying formations. There are threeoverlying bedrock formations,the Frenchman, Ravenscrag and Wood MountainFormations. TheRavenscrag is dividedinto upper and lower portionsseparated by the Hart coal seam, which is an aquiferin the Coronach area and which will providethe energy supply to the SPC power plant. Surfacedeposits overlying the bedrock formations include the Empress Group (a gravellayer), glacial deposits and present-day alluvial deposits.

Unlikesurface waters, most groundwatersnormally do not disp:Lay seasonal variationsin chemical properties. Groundwater chemistrydepends in part onthe chemical equilibrium established betweenthe groundwater and the permeable material throughwhich it flowsand on its positionwithin the groundwater flow system. As groundwaterflows through the subsurface its quality is affected by chemicalreactions with soil andgeological materials. Theproduct ofthese processes inthe Poplar RiverBasin is a groundwaterhigh insodium bicarbonate and with a relativelyhiqh TDS concentration.

Ingeneral, 'she lower geoloqicformations have hard water withrelatively high TDS concentrations.High concentrations of iron,manganese, boron, molybdenum, uranium, phenol and selenium were also notedin various samples takenin the lower layers.The surfaceformations, by contrast,generally have lower TDS - 18 -

Table 11-2 Geologic Formations in Poplar River Basin - Range in Geologic Formation Thickness GeneralThickness Formation Geologic Saskatchewan mntana Characterof Layer (m) ( ft) - Alluvium Alluvium 0-55 0-180 Floodplain deposits of gravel, sand and silt

Glacial deposits Glacial.deposits 0-30 0-100 Unconsolidatedtill, lake deposits, and glacial melt-water

Empress Group WiotaGravels 0-3 0-10 Gravel

Wood bbuntain Flaxville Formation 0-30 0-100 Sand and sandy gravel Formation

Ravenscrag Fort union Formation 50-245 165- Sandstone, siltstone, Formation, 800 clay ad lignite including Hart coal seam. Frenchman Hell Creek Formation Sandstone, siltstone, Formation 40-75 130- andshale Fox Hills Standstone 240

Bearpaw Formation Bearpaw Shale 335-365 1100- Shale and minor sand- 1200 stone beds

The hydrologic characteristics theof aquifer layers in the Upper Ibplar River Basin are described in detail in BAppendix of the Board's Report. Someof these characteristics are summarized in Table 11-3. (Source: Board Report) Figure 11-2 Schematic Diagram of Geologic Formations and Groundwater Flows (Source : Board Report) Table 11-3: Estimated Hydroisgic Characteristicsnf Generalized AquiferLayers of upel: Foplap River Easir,, Saskatchewanand Montana

Ratio of Mean Mean horizontal Saturated wm horonzontal vertical hydraulic Storage thickness transmissivity hydraulic . hydraulic eondztivity cmfficient m Cd/d,conductivity conductivity to vertical or spxific (m/d) (m/d) hydraulic yield hydraulic (m/d) (m/d) comdlwtivity I

h) 0 Valley-f ill I a1luvium"- 0-60 4.7 x 102 4.4 x 101 4.4 x 100 10: l 2.0 x 10-1 5 Glacial depits--" 0-25 3.7 x 10-3 3.5 x 10-4 3.5 x 10-5 10: 1 5.0 x lo-*

Wood Mountain Formation and Flaxville 0 Formation--" 8-14 9.5 x lo1 8-9 x 10 8.9 x lo-l 10:l 2.0 x 1Cf" 1 4 0-130 3.7 x 10 9.8 x 10"' 9.8 x loe4 1,OOO:l 1.0 x 1 1 3 0-5 5.0 x 10 2.0 x 10 4.0 x 10' 5: 1 4.0 x 2 50 3.7 x lo1 7.4 x lo1 1.9 x lo4 4,OOO:i 1.0 x 1 0 1 60 7.4 x 10 1.2 x 10 3.0 x 4,000: 1 2.8 x

(Source: Groundwater Report) - 21 -

concentrations, although the groundwater characteristics were quite variable in some places, particularly where the surface layers receive groundwater from the underlying formation. Groundwater quality is described in more detail in Chapter VI.

AQUATIC BIOLOGIC RESOURCES

A full discussion of the available baseline data on aquatic plants and invertebrates, fish and wildlife in the Poplar River Basin is contained in Appendix C of the Board's Report. In general, the biological resources of the Poplar River Basin are not large in quantity, due in part to the limited habitat available, and these resources are generally dispersed throughoutthe system.

The entire aquatic ecosystem mustbe considered in analyzing the resources of the Basin. Aquatic plants serve as food and as cover for aquatic invertebrates, fish, waterfowl,shorebirds and other wildlife. Aquatic invertebrates serve as a food source for fish and wildlife. The fish fauna in the Poplar River Basin is variable, with more species being present in the lower reaches. The habitat conditions for fish life in the upper portions of the Basin have apparently always been marginal, compared with other more productive areas of Montana. Despite these marginal conditions, however, apparently stable populations of walleye and northern pike were noted in the fish inventories compiled by the Board.

The inventory of water fowl in the Poplar River Basin was divided into ducks, Canada geese, shorebirdsand other waterfowl. The Board noted the East Fork Subbasin provided bettera duck habitat than any other portion of the Poplar River Basin studied by the Board. Reproduction by geese occurred on the upper reaches of the West Fork Subbasin. Ex.cept for the East Fork, geese were observed on all segments of the basin during the spring. The abundance and distribution of the various waterfowl species are described in Appendix C of the Board's Report. - 22 -

CHAPTER I I I

THE SPC PROJECT

The majorcomponents of the SPC projectdiscussed in this Chapterinclude the coal mining activities,the thermal power plant and thecooling reservoir formed by construction of Morrison Dam on theEast Fork. Included within thesediscussions are the coal storage and transport facilities and thecoal ash disposal system.

MINING

Coal mining tofuel the thermal power plant is being carriedout northwest of theplant site. The lignitepresent in the Hartcoal seam nearCoronach is a low-sulphur, high ash,very high moisture,moderate heat content fuel. The thickness of thecoal seams generallyrange between 2.4 to 3.7 m (8 to 12 ft) althoughthe seam is 5.5 m (18 ft) in places. At full operation with two units 3 the power plant is expectedto consume approximately 12,335 m 3 (435,600 ft ) of theselignite coal reserves daily. With the presentreserves the economic life of the SPC plant is projec,tedto be about 35 years.

There are many proceduresinvolved in opening, mining, and reclaiming of thearea to bemined nearCoxonach. Drilling and sampling, in the form of exploratoryholes and lignite sample chemicalanalyses, are continually necessary to determine the thickness of overburden and lignite. Dewatering of theHart coal seam area is necessary to drainexcess water fromabove and within the lignite seam in order to carryout the mining operation. Naturalstream drainage, precipitation and runoffentering the 23 mining pits must also be continuously pumped out. The removal and placement of topsoil and overburden, the recovery of lignite from the Hart coal seam (including mining, loading, hauling, processing and shipment) and reclamation are also part of the mining activities. Dewatering, mine pit and sump drainage, dive'rsions of water around the mine site and non-point source discharges from reclaimed areas are all of importance in varying degrees to the surface and groundwater systems in the basin. A complete description of the mining plan and associated facilities is given in Appendix E of the Board Report.

Dewaterin - Effects on Water

Because the Hart, coal seam is an aquifer and because other aquifers exist in the overburden, it is necessary to drain this excess water from the mining area in order to carry out the mining operation. At present, twelve dewatering wells in the Hart coal seam yield an average daily flow of about 11 dam3 (9 acre-ft) or 4120 dam3 (3,340 acre-ft) annually. This volume is expected to decline over a period of years to an estimated steady-state flow of about 1360 dam3 (1,100 acre~ft) annually. This dewatering flow is discharged to Gir~rd c~eek, which flows into Cookson Reservoir.

Water quality analysis of the mine water shows boron concentrations of 1.8 mg/l and TDS concentrations of 1100 mg/l, not too dissimilar from historic baseline conditions. However, as mining operations approach the Fife Lake area, seepage from the lake will increase and the result may be increased concentrations of various components in the water from the dewatering wells. The Groundwater Committee also indicated that drainage of groundwater from coal spoil areas adjacent to Girard Creek could increase in load of dissolved solids to. the reservoir. Overall, however, although some spatial and temporal variations can be expected, mine dewatering is not expected to have a major impact on water quality 24

in the Basin. These factors were considered in developing the plant operations model which predicts water quality at and below the boundary, and which is discussed in Chapter VI.

The water removed during dewatering activities will be a major; loss to the groundwater supply in the mine area around Coronach, amounting to a steady-state flow of about 1360 dam3 (fiOO acre-ft).' However, recharge of the groundwater system will occur as a result of inflow from Cookson Reservoir, as well as normal infiltration from precipitation and snow-melt. The Board's Groundwater Committee used two mathematical models to simulate the behaviour of the groundwater system and to predict groundwater level changes due to coal seam dewatering and to the influence of Cookson Reservoir. The model too.k into account the proposed mining plan, appropriate dewatering discharge rates, water level changes in the reservoir, and aquifer characteristics. The influence of the reservoir is discussed in a later section of this Chapter.

The Board studied the effect on groundwater due to dewatering activities and the maximum decline in groundwater levels that would occur. Predicted effects in the upper Ravenscrag Formation are especially important because many wells in Montana reach in this layer. The predicted area for significant declines in water levels in the upper Ravenscrag as a result of dewatering extends southward from Fife Lake to northern Montana. The maximum water level decline predicted in Montana for this formation is 0.7 m (2.3 ft) near the International Boundary, due south of the mining area.

Mining Ac~tviti'~s o~ ~wSfgnlf!ca~£e

There will also be. some seepage and precipitation and spoil pile runoff that will enter the mining pit and which must be pumped out. The predicted total average annual volume of such water is - 25 - about 672 dam3 (545 acre-ft) which is a relativelysmall quantity of water. The quality of this water is expected to be generally good sinceanalysis of test data show TDS concentrationsof about 560 mg/l and boron concentrations of about 0.8 mg/l.

Surfacewater diversion around the mine site will consist of re-routingrelatively unaffected natural surface water into a sump ornatural depression in thearea, with subsequent pumping into GirardGreek. The quantity of suchwater will depend on the location and extent of the mining activity and on the preci,pitation. Because such water is simplybeing diverted, and assuming suitablefacilities for so doing areprovided, no significantchanges in water qualityare predicted.

Non-pointsource drainage will varyas a function of the stages of the mining activities, which will disrupt an area of about 2 42 km2 (16 mi ) on eitherside of GirardCreek during the lifetime of the SPC project. The estimatedpost-mining runoff and sedimentyield would increaseabout four and ten times the pre-mining ratesrespectively. They will thengradually return to pre-mining values by theseventh year after the reclamation activities begin.

-THE POWER PLANT

The majorcomponents of the power plantare outlined in Appendix E of theBoard's Report. In this discussion below those aspects of the power plant which couldaffect the water quality in Cookson Reservoirand/or the East Fork are examined. One feature of particularimportance is theash disposal system. The original design of theash disposal system has been substantially revised, and both theoriginal and currentdesigns are discussed below. The condensercooling water system is anotherimportant factor which will affect water quality. Coolingwater for the power plant will - 26 -

be drawn from Cookson Reservoirvia asubmerged intake in the reservoir and the coolingwater will then be discharged from the plantinto a discharge canal which entersthe reservoir near Morrison Dam. Deposition of atmosphericemissions from theplant is anotherissue discussed below.

Ash Disposal System - The Oriqinal and CurrentDesigns

The Board determinedthat the major factor contributing to surfacewater quality deterioration as a result of the SPC plant would have been theonce-through ash lagoon disposal system and primarily boron which was found toreadily dissolve from the ash. This conclusion was highlighted in the Commission's InterimReport to Governments in February 1979. The Board Reporttherefore dealt essentially with theoriginal once-through design and measures to mitigatefor adverse effects from this system. Primarilyas a result of theinvestigations of theBoard, SPC revisedthe design forthe ash disposal system at the plant and at the Commission's publichearings in September, SPC presenteddetails of thecurrent designfor the ash disposal system. The Commission then requested the Board toevaluate the new information and at the close of the secondround of publichearings in October a supplementary study was submitted by thePlant, Mineand ReservoirOperations Committeeand the GroundwaterCommittee of the Board on the revisedrecirculating ashlagoon system. Both theoriginal and currentsystems are di.scussed below.

The quantity and quality of solidwastes produced at any power plant depends upon thecharacteristics of the coal being burned,the type of boiler and operatingconditions, and the efficiency of theparticular pollution-control equipment being used. In thecase of the SPC plantthe ash recovered from the bottom of theboiler (bottom ash) will averageabout 23.5 percent of the total ash produced. Fly ash, the ashcarried up the stack, will - 27 - comprise the remaining76.5 percent of the total ash. Bottom ash will be collected wet in a hopper beneaththe boiler, while flyash wil.1. be collecteddry in a 99.5percent efficient electrostatic precipitator. Boththe bottom ash andfly ash will be pumped togetherin slurry form to theash lagoons at anaverage rate of about 130 l/s (4.6cfs).

Theoriginal once-through ash di.sposa1system was intended to operate with three lagoonsin sequence. The first lagoonwould hawe beenfilled with the ash slurry until the water reached a level about 1 m (3.3 feet) below thetop of the dikesurrounding the lagoon.The slurry would then be allowed to settle forone monthr followed by a onemonth decant period ,when the water in the lagoon above the settledash would be released backinto a holdingpond and theninto the reservoir via the cooling water dischargechannel noted earlier. Duringthe ash settlingand decanting period of the firstlagoon, subsequent ash slurry would be put sequentially into thesecond and third lagoons and the above process performedin similar sequence. When all threelagoons were filled,the next set ofthree lagoons would be broughtinto service. Seepage control in theoriginal system was to havebeen achieved by reworking and compactingthe upper 600 mm (2 ft) of theoriginal base of the lagoon to achieve a permeability of 1.5 x low5 cm/s (5 x ft/s).

TheBoard assessed the potential impact of thisoriginal ashdisposal system in its Report to theCommission, however, as notedabove, SPC revised its ash disposal. system design so that no water in the lagoonwould be transported by surface flow inthe dischargechannel to thereservoir.

Thecurrent ash disposalsystem is thatof a recirculating ashlagoon system. It is similar to one of therniti.gation alternativesstudied by the Board but differs somewhat because of - 28 -

location, lagoon size,seepage rate estimates and operational characteristics. The current ash disposalsystem now being i,nstaL.Led i.ncludesthree ash lagoons and a polishing pond, although onLy onelagoon plus thepolishing pond will be operatedat any given time. The polishing pond permitsfurther settling 'of any ash in thewater before the water is recirculated back tothe plant for reuse in theproduction of more ashslurry.

The water quality impacts of thedisposal of thecoal ash slurry in ash lagoons will depend on severalfactors including the quality and quantity of theash slurry, the lagoon configuration and methodsof operation,the permeabilities of thebase and side materials of thelagoon, the hydrogeologic characteristics of the soils underlyingthe lagopn site,the degree of attenuation by the underlyingsoils of thecontaminants in thelagoon seepage water and theposition of thelagoons relative to the groundwater flow regime.These factorsare also discussed briefly below.

FactorsAffecting Poplar River Water Quality

The majorwater qualityimpacts of the SPC plantidentified by the Boardwere contamination of groundwater and of surfacewater in Cookson Reservoirprimarily due to theoriginal once-through ash disposalsystem. The use of a recirculating ash disposalsystem, however,should essentiallyeliminate concerns about contaminated surfaceflow from theash lagoons to the reservoir, barring unforeseencircumstances. Concernover potential groundwater contamination by seepageremains a concern. Such contamination will be a function of theexisting groundwater regime in thearea and the characteristics of theash lagoon system, as discussed below.

- Existinq Groundwater Regime: The existinggroundwater flowsystems for the Poplar River Basin, as well as a description of thegeology and hydrogeology of thearea were analyzed by the Board - 29 -

(Appendix B). Subsequent to the Board Report, further tests by Spc were also conducted in the area of the ash lagoons to more accurately define the nature of the soils at the site.

The groundwater systemof the Upper Poplar River: Basin is relatively complex. There is, however, a relative abundance of detailed information on the soils and geology of the Coronach and adjacent areas, reflecting the concentration of data-gathering near the SPC plant, mine and reservoir areas. The geologic system includes, from oldest (deepest) to youngest, the Frenchman Aquifer, the Lower Ravenscrag Aquifer, the Hart Coal Aquifer, the Upper Ravenscrag Aquifer, the Empress Group, the glacial till and the valley-fill alluvium. These geologic strata are described in the Board Report. There is approximately 17 m (56 ft) of glacial till consisting of sands and gravels which overlie the Empress Formation. The till has an upper oxidized layer of about 9 m (30 ft) in most areas, but highly variable and with a well-developed joint pattern. The upper oxidized layer is underlain by a lower unoxidized layer, approximately 8 m (26 ft) thick which also has fractures which have a tendency to decrease with depth. In some places, however, the upper oxidized layer is in direct contact with the Empress layer or else has a very narrow (1 m or 3.3 ft) unoxidized intermediate layer. The underlying Empress Group formation consists of sands and gravels that have been disrupted by glacial activity which occurred subsequentto the deposition of the formation.

The Board's Supplementary Report includesan evaluation of all available water level data, and interpretation of these data to derive piezometric maps. During the public hearings there were some questions concerning the interpretation of some of the hydrogeologic data, and the anticipated seepage and groundwater flows as presented by SPC and its consultants. These concerns were generally reconciled in the Supplementary Report. - 30 -

In summary, the report confirmed there is a strong groundwater recharge from the reservoir, a componentof groundwater recharge from the west, and a trough of groundwater discharge to the southeast. The permeabilities of the various geological layers underlying the ash lagoons then become important factors'in estimating seepage flow ratesand patterns of flows fromthe lagoons.

"II- Quantity and Quality ofAsh Slurry: Water qualityin the ash lagoons is of concern both because this water will be of poorer quality than the reservoir or the normal groundwater, and because it may also contain high concentrationsof contaminants. The various constituents that will be dissolved from the ash in the slurry water will generally determine the impacts of the ash slurry on the lagoon water quality.

The various waste inputsto the ash lagoons, their estimated quality and the resulting water quality in the ash lagoons are summarized in the Board Report (Appendix E). Of all the waste inputs to the ash lagoons, the ash slurry contributes more than 90 percent of the added concentration for many of the elements in the lagoons.

An ash lagoon water quality' study was conducted atthe Boundary Dam generating station whichis similar to the situation at. Coronach, to verify the assumptions made in extrapolating the results of laboratory ash leachate teststo estimations of ash lagoon water quality. The tests are also described in Appendix E. Considerable variability exists betweenthe results obtained for different ash samplesp and caution should thereforebe used in extrapolating results. Information in the Saskmont Report to the Commission showed boron could build up to the level of 70 mg/l in laboratory tests, however, there were many explanations presentedas to why this is considered a theoretical, upper limit. At Nanticoke generating station in Ontario, with a similar recirculating ash - 31 -

disposalsystem, baron concentrations in theash lagoon water are in the 20 mg/l range. In any eventthe use of 50 mgJl by the Board as a seepagewater quality estimate could well be higherthan the concentrationthat will actually be experienced and probably adds an element of conservatismto the model. resulAs.

- Permeability*- of Ash- Lagoon SitesI_ Various techniques were utilized by the Board and by SPC and its consultantsto estimate the horizontal and verticalpermeabilities of thematerials lining and underlying t,he ash lagoons and theresulting leachate seepagerates. he independent.seepage computations are essentially similar and are based on Darcy's Law Equation (discussed in the following section), however, there is a need toclarify the various estimates of permeabilities whichhave been presentedto date since thereported permeability values for the materials at the lagoon site have variedduring the study period.

The Plant, Mine and ReservoirOperations Committee selected a rangeof possible seepage rates based on the field measurements sf permeabilityavailable at thattime. A range of permeabilities from IO-' em/s to cm/s (3.3 x ft/s to 3.3 x lo-* ft/s) for the till was usedbecause the geologic investigations indicated thesite materials were notconsistent throughout the till. This directlyaffects the permeabilities and seepageflow directions and magnitudes. This range was laterrefined by theOperations and GroundwaterCommittees taking into account.subsequent geotechnical field investigations and analytical work done by consultants to §PC (Cl.ift.onAssociates, 4.979, Saskmont Engineering, 1979 and Camp,

Dresser and McKee (CDM) I 1979) I These further studies enabled a

l_l-"l__".".".- l_l-"l__".".".- * The term"hydrau4.i.e conductivity" was used in place of "permeability" in theBoard's Report and Appendix B. Thetwo termsrefer to the rate at which water may be transmittedthrough a medium and areconsidered synonymous in this report., - 32 -- more critical analysisto be made for all existing data and at the same time reflect the current ash lagoon design and operation (e.g. - size, number, location and material design ofthe lagoon).

The permeability of the floor of the ash lagoon' is a critical factor controlling seepage of ash lagoon leachate fromthe lagoon. The current system presently being installed calls for a 300 mm (1 ft) thick compacted till base having an estimated -10 permeability of 1 x cm/s (3.3 x 10 ft/s) . Board estimates of permeabilities forthe oxidized and unoxidized till layers were 6 x LO-' cm/s (2 x ft/s) and 2 x loe7 cm/s (6.5 x 10"' ft/s) respectively. Although it is difficult to make precise determinations of permeabilities, the above estimates were considered to be sufficiently accurate to provide a good order of magnitude estimate of the seepage rates from the ash lagoons. The different permeabilities ofthe various underlying layers can then be combined mathematically to give an "equivalent"or average permeability for the three-layer system (Table 111-1).

Table 111-1 Estimated Permeabilities of Geologic Layers Underlying Ash Lagoon Area

Permeability

cm/s Ift/s - -10 Compacted oxidized till (lagoonlining) 1 x 3.3 x 10 Oxidized till 6 x lom5 2.0 x Unoxidized till 2 x 6.6 x lo" Equivalent permeability 2.5 x 8.2 x

(Source: Supplementary Report)

These best estimate permeabilities can then be substituted into the appropriate seepage rate equations to compute seepage rates from the ash lagoons. - 33 -

- Ash Lagoon SeepageRates: Seepage rates can be calculated using thewell known Darcy's Law Equation: Q = KIA 3 where Q = seepageflow rate (m /s) K = permeabilitycoefficient (m/s) I = hydraulicgradien (m/m) 2 A = cross-sectionalareas of theseepage flow path (m )

Values of theabove parameters (K, I and A) canvary, thereforeprecise determinations of seepagerates are not practical. One can neverthelessproduce a range of estimates within which valuesshould likely occur. For example,seepage can be calculated on thebasis of singlepermeability coefficients or on thebasis of equivalentpermeability. The hydraulicgradient can be based either on the normal operatinghydraulic head on thebase of the ashlagoon or the difference between averagegroundwater table and averagelagoon water level. Obviously some judgment is required in making calculations. Assuming a 0.3 m (1.0 ft) till lining, a lagoon and polishing pond area of 550,000 m2 (136 acres), an equivalentpermeability of 2.5 x cm/sec and heada differential of about 10 m (33 ft), a seepagerate of approximately 1 l/s (.035 cfs) downward throughthe ash lagoon lining and till is calculated.

Therehas also been controversyover the direction the ash lagoonleachate will flow afterseeping through the lagoon lining and upper till layer. The existing groundwaterflow within the lowerEmpress Group is predominantly in a southeasterlydirection away from thearea of theash lagoons towards the East Forkbelow Morrison Dam. Nevertheless,as described previously, there is a layer of unoxidized till which exists between the Empress Group formation and the upper till layer. This layerhas a significantly lower permeabilitythan the Empress layerand, as a result, ash lagoonseepage may notpermeate through tothe Empress layer in the same quantities as originally assumed. There would instead be an - 34 -

increasedtendency for a lateralspreading of the ash lagoonseepage water in the more permeableupper oxidized till layeralong the top of theunoxidized till layer, towardsthe reservoir. In contrast, on a most severecase assumption, all of theleachate seepage would Le divertedvertically into the Empress layer and thenceinto the East Forkbelow Morrison Dam. In actualoperation, however,one would expect a combination of these two phenomenon with a portion of theleachate being diverted laterally anda portion seepingvertically into the Empress layer,primarily because the distribution of theunderlying geologic layers material is not consistent.

The SupplementaryReport estimated vertical seepage through the lining and till layerto be about 1 l/s (.035 cfs), with a probablerange of 0.5 to 2.0 l/s (.018 to .070 cfs), and estimated horizontalseepage to Cookson Reservoir in therange of 0.1 to 1.0 l/s (.004 to .035 cfs).

- Water QualityEstimates: Using theseepage rates suggestedabove, the Supplementary Report used the reservoir operational model developed by thePlant, Mine and Reservoir Operations Commi.ttee torefine the Board's water quality estimates based on theoriginal ash disposal. Data on thecurrent design is summarized in Chapter VI of this report.

AtmosDhericEmissions

Emissionsfrom the plant stack, as wellas fugitive dust emissions from theplant and mining activities, will be deposited within thePoplar River Basin. These are discussed in detail in Appendix E of theBoard's Report. Deposition concentrations of total suspended particulates,sulphur dioxide and nitrousoxides were estimatedfor the area adjacent to the SPC plant. The aerial deposition of materialsdirectly on thereservoir surface was - 35 -

2 estimated to be 6.3 g/cm /year (0.1 lb/sq in/year) which was considered to be an insignificant quantity relativeto other inputs.

_..l.""..-ICooP.ingater System

Condenser cooling water systemsare used at thermal power p%.antsto condense steam fromthe turbines into water so that it can then be recirculated back through the steam cycle tocool the turbines. Large volumes of water and a sufficiently large receiving water system are requiredto permit effective heat dissipationand hea,t transfer to the atmosphere. At the SPC plant cooling water wil:l. be drawn from thereservoir at estimated rates of 6,700 l/s (237 cfs) and 13,400 l/s (474 cfs) for a one and two unit plant respectively. The cooling system for the SPC plant is described in Appendix E of the Board Report. Two relevant topics to the present study are the cooling water discharge from the reverse osmosis plant and the warm water discharges to Cookson Reservoir.

The function of the reverse osmosis plant willbe to reduce the dissolved solids concentrationin the incoming reservoir water. The estimated reduction willbe more than90 percent, and the solids removed will be concentratedin a reject flow ofwater.

The reject water will havea relatively high salt Concentration, about 2.5 times the concentration in the reservoir water, The flow rates are relatively low, however,2.1 l/s (-074 cfs) and 4.2 l/s (.148 cfs) for 1 and 2 units respectively and therefore the net effect shouldbe of little significance.

The increased heat to Cookson Reservoir due to discharges. from the cooling water system could create an estimated maximum temperature rise in the reservoir, in the most severe conditions, of about 17OC (31°F) above ambient. The quantity and timing of warm water from the reservoir may have effects on the fish below the International Boundary. - 36 -

COOKSON RESERVOIR

Cookson Reservoir is on theEast Fork approximately 3.5 km (2 mi) northof the International Boundary. At its full supply level of 753.0 m (2470.4 ft), thereservoir has a surfacearea of 3 7.4 million m2 (1820 acres) and a volume of 41.2 million m (33,400 acre-ft). The reservoir was createdto provide cooling waterfor the operation of the SPC plant. Morrison Dam contains threeoutlets to pass waterdownstream including a low level riparianoutlet for low-flow releasesscheduled in the apportionment, a gatedservice spillway for passing flood flows, and an emergency spillway in theevent of anextreme flood. Information on thereservoir and operations is contained in Appendix E ofthe Board'sReport. The reservoir is a critical element in the operation of theplant and is a major factor in determiningthe quantity and quality of theflow in theEast Fork at the International Boundary.Other associated factors include overflows from Fife Lake, natural and forcedevaporation, and seepagethrough, beneath and aroundMorrison Dam.

NaturalInflow to Cookson Reservoir

Naturalflows on theEast Forkwere altered with the construction ofMorrison Dam. In themathematical modelling of the effects of thereservoir over the period of record it was assumed thathalf the present use baseflows in theEast Fork atthe boundary would have enteredthe reservoir and theother half would have enteredthe river betweenthe dam and the boundary.Based on the period of record,the model then computed reservoirinflows that would haveoccurred for each month. Precipitationonto the reservoir was alsotaken into account.

Inflowsto the reservoir wereassumed to have dissolved elementconcentrations inversely proportional to the flow rates and - 37 -

the Surface Water Quality Committeeof the Board provided regression equations for concentrations and flows.

Overflows from Fife Lake,a largen shallow impaundrnent in the upper part of the Girard Creek Basin is another source of inflow to Cookson Reservoir. Water in the lake is generally of paoK quality with mean monthly TDS levels ranging from 1500 to 25170 rng/.l and for 1977 boron levels ranging from 3.1 to 5.7 my/].. This is due to the small quantity of annual inflowand the large surface area for concentration of salts due to natural evaporakion. 'There is a small control structure atthe outlet of the lake whi.ch prevents natural drainage downstream into GirardCreek, 0verfl.o~from Fife Lake occurs on the average about onceevery ten years when sufficient water accumulates in the lake to raise its water level so that it overflows into Girard Creekand subsequently into Cookson Reservoir. Fife Lake overflowed in both 1975 and 1976 and both overflows were noted to have causeda deterioration of downstream water quality.

Evaporation from Cookson Reservoir

Computations of both natural and forced evaporation rates in Cookson Reservoir are discussed in Appendix E. Since evaporat-ion losses from the reservoir provide a directlink between water quantity and quality, it is important to establishan estima.te sf these losses.

The net natural evaporation fromCookson R.eserv0i.r is estimated to average about 0.6 m (2 ft) annually, with a mean monthly value in late summer of about 0.2 rn (0.7 ft). 14ssumi.ng a full reservoir in the spring, this net evaporation resultsin an average annual water loss ,of 6863 dam3 (5565 acre-ft) or about 17 percent of the full reservoir volume. Forced evaporation for a two unit plant is estimated to be 3300 dam3 (2765 acre-ftj ar about 8 percent of the full reservoir volume. - 38 -

Seepage from Cookson Reservoir "

Some seepage from Cookson Reservoirthrough, beneath and aroundMorrison Dam tothe East Fork is expectedto occur The seepagerate through and beneathMorrison Dam was estimated ,to be about 25.5 l/s (0.9 cfs), This flow is nearlyequal to the recommended minimum continuousapportionment flow of 28 l/s (1. cfs). The seepagewater quality is expectedto be essentially the same as that of thereservoir water.

Estimates were also made of seepage from thereservoir into the EmpressGroup sand and gravellayer. These estimatessuggest that if flow were tooccur fromeach side of Cookson Reservoir, it would averageabout 7.1 l/s (0.25 cfs). This seepagewater quality is also assumed to be similarto that in thereservoir. - 39 -

CHAPTER IV

THE BOARD'S INVESTIGATIONI "

The results of the Board's investigation are given in detail in its Report to the Commission and the accompanying five appendices. The appendices are the reports of the five technical Committees established by the Board to aid it in its investigations. These appendices served as the basis for the Board's Report to the Commission. There is also one minority report by a Board member and two minority reportsby Committee members, which indicate that diff.erences of view aroseon certain technical and procedural matters. Nevertheless the Board Report is a unanimous document. In addition, after the Commission was informed of the intention of SPC to proceed witha revised design for the ash handling system, a Supplementary Report entitled "Preliminary Evaluation of Revised Design and Seepage Estimated for the Ash Disposal System at the PoplarRiver Generating Station" was prepared by the Plant, Mine and Reservoir Operations and Groundwater Committees of the Board. This report evaluates the current ash handling system and the further hydrogeological investigationsand assessments submitted by SPC at the Commission's public hearingsin September. The main findings ofthe Supplementary Report are discussed briefly below and in Chapter VI. The Board also provided, in writing, answers to certain questions raised at the public hearings. In addition the Canadian Co-Chairman of the Operations Committee submitted a report to the Commission entitled "Comparison of Natural Spring Flowsin the East Poplar River with Estimated Spillage from MorrisonDam."

It should be noted that asa result of the current SPC design and further hydrogeological assessments, some of the Board's and technical Committees' original estimates of the impactsof the - 40 - plant were revised in theSupplementary Report. Consequently, certainsections of the Board Report and appendicesrelating to predictedimpacts nee.d to be read with theserevisions in mind. In view of the above considerations,the following sections of this Cl-:*-pter,with theexception of theSupplementary Rp,,ort and Summary uf Effectssections, will notdescribe the Board's and Committees' findings with regardto future water quality.

SURFACE WATER QUALITY

An inventory of existingwater quality data for nine locationsthroughout the Basin was compiled using records from federal,state and provincialagencies and consultants and thedata were enteredinto a master file on NAQUADAT, theCanadian national computer datastorage and retrieval system. Summary tables were preparedto indicate annual, seasonal and monthly variability in the data. Computer modelswere used toestimate the flow and concentrations of TDS, some major ions, boron and sodium adsorption ratio (SAR) which would accompany eachpossible development scenario. A waterbudget model (KARP 11), an adaptation of the U.S. Bureau of Reclamation HYD-2 program, was used toproject the flows expected with proposedapportionment and assumed level of development.Another model ("E) was used toestimate the quality and quantity in Cookson Reservoir.Output from the MME and KARP I1 modelswere used as inputto a KARP I11 model tosimulate water qualityat selected locations.

Because of thepaucity ofpre-impoundment water quality data(i.e., before 1975), particularly on theEast Fork, coupled with theinfluence of Fife Lake discharges on thatdata collected since 1974, the Commission recognizedthe importance of assessing thesebaseline model-projected conditions against which thewater qualityimpacts of the project were to be compared. A detailed analysis of the adequacy of the models used in the Board study is contained in Chapter VI of this report. It shouldalso be noted - 41 -

that the available water quality data did not includea period of drought, such as occurredin this area in the early 1930's. As a result, concentration versus flow regression equationsfor the model did not take into account naturally high concentrationsof constituents which mayhave occurred during periods of very low flow of less than 37 dam3 (30 acre-ft) in any month.

The study found that presentwater quality in the Basinhas been strongly influenced by flow, with concentrations of TDS and the major ions being greatest when stream flows arelow. TDS concentrations usually increased as one moved downstream. Boron concentrations were foundto average about 1 to 2 mg/l in the East Fork and about 1 mg/l elsewhere. During the spring runoff dilution from snowmelt greatlyre.duced the concentration of dissolved minerals. Highest concentrations of nutrients generally occurred during spring and summer when median total nitrogenis in the range of 1 to 2 mg/l and median total phosphorusis in the range of 0.05 to 0.3 mq/l. Except for the winter period when dissolved oxyqen (DO) can fall to near 1 mg/l under the ice cover, the study found DO content of the Basin waters remain greater than4 mg/l. Iron and manganese are the only metals presentin significant quantities in the Basin.

GROUNDWATER QUANTITY AND QUALITY

Groundwater assessment wasbased primarily on an appraisal of data and information already available froma variety of sources prior to the Board's study. A consultant collected and collated those data and information available for Saskatchewan. Chemical data were obtained fromSPC records and studies by the U.S. Geological Survey and the Montana Bureau of Mines and Geology. Most of the chemical quality studiesin Montana were supportedby the U.S. Environmental Protection Agency. New data obtained as a result of Committee activities included chemical analysesfor a number of - 42 - groundwater and surface water samples in the Basin and test hole and aquifer test: data for a number of new holes in Montana. The new data helped to establish the general reliability of earlier analyses as indicators of groundwater chemical qualityand provided information on the continuity and hydraulic properties o'f the Hart coal seam. The complexity of the Poplar groundwater system dictated the use of two mathematical modelsfor simulation of the total system behavior. The two models were a finite-element model. designed to evaluate the combined effects of dewateringand natural recharge by precipitation, and a finite-difference model designed for the estimation of water-level changesin the layered aquifer system.

It was foundth,at groundwater is used in the Basin for domestic and municipal purposes and is the main source of water to the river during low flowperiods. A generalized description of the geological formations in the Basin is given in Chapter 11. Under natural conditions the chemical quality of groundwater in formations lying under glacial and preglacial deposits often exceeds the recommended levels for iron, manganese, nitrate,non-ionized ammonia, phenols, copperrfluoride, SAR, sulphate, zinc, and selenium. In the various formations the groundwater is alkaline with TDS and boron concentrations in the relatively high range.

The maximum drawdown of water levels due tothe SPC project was predicted to be 0.7 m (2.3 ft) near the International Boundary after 35 years of dewatering,and the predicted maximum risein water level after 75 years of reservoir leakage was predictedto be 0.1 m (.3 ft) near the boundary south of the reservair. The groundwater south of the International Boundary was not expected to be degraded by the SPC project. - 43 -

BIOLOGICAL RESOURCES

All available data on aquatic and riparian vegetation, aquatic invertebrates, fish and wildlife was reviewed in the study. For each group information was obtained can species occurrence, distribution, abundance and tolerance to environmental stress. Using these data plus surfacewater quality predictions, the impacts on biological resources of the SPC project and the proposed apportionment was assessed using appropriate indicator species for each resource group.

In general, it was found that the proposed water apportionment would lead to substantial changes in the flow characteristics of the east Fork and Poplar Rivers causing habitat changes and resulting in moderate to severe impacts on macrophytes, walleye and duck production. However, it was predicted that the SPC project would likely not cause significant adverse impacts on the biological resources below the confluence of the mainstem with the West Fork, and that there would not be any adverse impacts to these resources due to changes in water quality.

USES AND WATER QUALITY OBJECTIVES

The inventory of historical, existing and projected future water uses in the Poplar River Basin was based primarily on information presented in the Poplar River Apportionment Task Force Report of 1976, and included examination of background information, personal communications with key individuals and firsthand observations of projects in the basin. The level of uses presented in the Board Report was notexactly as indicated in the Task Force Report, however, the differences are minor and are discussed in Chapter VI.

Existing major water uses in the Poplar Rive' Basin include municipal supply, stock watering and irrigation. The principal uses - 44 - have historically been relatedto agriculture, with irrigation accountingfor about seventy percent of thetotal wateruse in the basin. Water usage in the basin has alsoincreased substantially over theyears since the 1930's and thetypically variable water supply from oneyear to the next has greatly affected water use.

Almost all of thefuture water use in Saskatchewan is relatedto the SPC plant.Future water uses in Montana are predictedto include increased municipal, stock watering and irrigationusage. Based on thetrends of thepast 15 years, irrigation use is likelyto have a significantincrease. In addition,there are plans to use 74,000 dam3 (60,000 acre-ft) of waterfor irrigation on theFort Peck IndianReservation.

The Usesand Objectives Committeeof the Board recommended multiple-purposewater quality objectives for the Basin. based on the bestavailable information. The Commission has commentedon these objectives in Chapter VI of this report. The Committeenoted that the waterquality objectives developed for the study couldnot be expectedto ensure absolute protection for all wateruses, however, they would give an adequateassurance of protection until better information becomes available.

With regard to boron and TDSl theparameters ofmost concern in thePoplar River Basin, the Committee recommended that (a)the long-term mean valuefor boron be 5.0 mg/l with valuesas high as 8.0 mg/l beingpermissible for short periods oftime (three months orless) during the irrigation season, and (b) thatfor TDS 1000 mg/l be the limit on a long-termbasis, with 1500 mg/l being acceptableduring shorter time increments (less than three months).

In commenting on.theCommittee's water quality objectives, the Board indica,ted that in orderto prevent additional yield reductions of barleyirrigated downstream of theInternational - 45 -

Boundary, the objective for boron should be the natural concentration (median of about 2 mg/l in the irrigation season). on the other hand, the International Boundary objectivefor boron to prevent yield reductions of irrigated alfalfabetween the International Boundary and the confluence of the East and Middle Forks was 6 mg/l. The Board recommended that the TDS objective at the boundary be 1000 mg/l over a long period (10 years) and 150Q mg/l over any three month period in the irrigation season.

-IPLANT MINEAND RESERVOIR" OPERATIONS

A full description of the SPC project is contained in Appendix E of the Board Report.

There was an extensive reviewof available information on the SPC project including the methodof mine reclamation, leachability of constituents from the coaland ash, subsurface conditions in the ash disposal areaand details of the power plant waste management system.

In summary, ,the Board determined that the major contributing source to surface water quality deterioration wasthe original once-through ash disposal lagoon system,with the element of primary concern being boron which was found to readily dissolve from the ash. It was also found that seepage from theash lagoons could be significant dueto the nature of the upper till layer in the ash disposal area and that corrective action shouldbe taken. Evaporation loss from Cookson Reservoir, particularly natural evaporation, was identifiedas a major factor in total dissolved solids buildup in the reservoir. There were other minor concerns associated with the mine dewateringand waste management systems. Several possible mitigation options were evaluated,and it was concluded that feasibleand practical mitigation measures were available that would permit thewater quality objective recommended - 46 -

by the Uses and Water QualityObjectives Committee of the Board to be met. Severalmitigation measures and/or design criteria were specifically recommended for theash disposal system, TDS reduction, power plantwaste steams, the mining operation,overflows from Fife Larce, power plantoperation and inspection of pollutioncontrol features.

SUPPLEMENTARY REPORT ON THE CURRENT ASH DISPOSAL SYSTEM

As discussed in Chapter 111, a SupplementaryReport was preparedto evaluate the SPC consultants'seepage estimation procedures and thepredicted impacts of thecurrent ash disposal system on thewater quality of theEast Fork atthe International Boundary. The reportconcluded that although some of the consultants'methodologies could be questioned, and uncertainties in thedata base existed, the predicted seepage rates in thosestudies were good order of magnitudeestimates. The SupplementaryReport also re-computed concentrations ofboron and TDS at the boundary takinginto account the current seepage estimates and thecurrent recirculatingash disposal lagoon design. Thesere-computed concentrationsare presented in thefollowing section.

SUMMARY OF EFFECTS

The Board'sinvestigation of theoriginal ash disposal designfound that seepage from theash lagoons would have had the greatesttransboundary effects. A number of estimates were made of theseepage flow from theash lagoons and thepredicted water quality in theEast Forkbelow Morrison Dam. Based on the informationavailable to the Board atthe time of their study, the flow of leachate from a singleash lagoon with a once-throughdesign was estimatedto be as high as 17.4 l/s (0.61 cfs), and for a recirculating lagoondesign the estimated seepage rate was 5.0 l/s (0.18 cfs). Based on furtherinformation detailed in the supplementaryReport, seepage estimates were revisedto a probable - 47 - range of horizontal seepage to Cookson Reservoir between0.1 to 1.0 l/s (.004 to .035 cfs), and a vertical seepage rate to the East Fork below the Morrison Dam within the range of 0.5 to 2.0 l/s (.018 to -07 cfs). The Supplementary Report predicts the monthly mean boron and TDS concentrations for the East Fork at the International Boundary with these revised seepagerates. The probable maximum seepage rate was estimated to be 2.0 l/s (.07 cfs) to the East Fork below Morrison Dam and 0.5 l/s (.018 cfs) to Cookson Reservoir, and the probable order of magnitude seepage rate was estimatedto be 1.0 l/s (.035 cfs) to the East Fork and 0.1 l/s (.004 cfs) to the reservoir. Figures IV-1 to IV-4 compare the various predicted monthly mean boron and TDS concentrations for the East Fork at the International Boundary and locations downstream in Montana. - 48 -

t

JAN FEB MAR JULAPR JUN MAY AUG SEP OCT NOV DEC

Figure Iv- i COMPARISON OF PREDICTED BORON AND T D S CONCENTRATIONS FOR ORIGINAL AND CURRENT ASH DISPOSAL SYSTEMS: EAST FORK AT THEINTERNATIONAL BOUNDAPY -. 49 -

JAN FEB JAN MAR APRJUL JUN MAY AUG SEp oCT DEC NOV

Figure Iv-2 COMPARISON OF PREDICTED BORONAND T D S CONCENTRATIONS FOR ORIGINAL AND CURRENT ASH DISPOSAL SYSTEMS: EAST FORK NEAR SCOBEY 14

2

0

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

I600

I400

1200

IO00

Figure IV-3 COMPARISON OF PREDICTED BORONAND T D S CONCENTRATIONS FOR ORIGINAL AND CURRENT ASH DISPOSAL SYSTEMS: POPLARRIVER NEAR SCOBEY - 51 -

JAN FEB MAR APR MAY JUL JUN AUG SEP OCT NOV DEC

Figure IV-4 COMPARISON OF PREDICTED BORON AND T D s CONCENTRATIONS FOR ORIGINAL AND CURRENT ASH DISPOSAL SYSTEMS: POPLARRIVER NEAR POPLAR - 52 -

CHAPTER V

PUBLIC HEARINGS I

Publichearings on theReference were heldin Scobey, Montanaand Regina, Saskatchewan on November 2 and 3, 1977 respectively,with the Board inattendance, to obtainviews of the publicand provi'de guidance in planning the investigation.

Followingpublication of the Board's Report to the Commissionin July 1979,further public hearings were conductedby theCommission to provide a convenientopportunity for all those concernedwith the water quality of thePoplar River and the transboundary water qualityimplications of the SaskatchewanPower Corporationthermal power stationnear Coronach to presenttheir views, At thepublic hearings all thoseinterested were given an opportunity to expresstheir views orally or presentdocumentary evidence.The Commission also acceptedwritten submissians received subsequent. to the respectivehearings.

Thefirst set ofpublic hearings was heldon September 10, 1979 at Scobey and onSeptember 11 at Coronach. It becameapparent duringpresentation of submissionsin Scobey that interested parties in the area hadnot had sufficient time to reviewthe report. A further set of hearings was requested.The Commission completed the first round of hearingsand subsequently scheduled a second set of hearings whichwere heldon October 15 inRegina and October 1,6 and 17in Scobey for the purposes of receiving further testimony.

Verbatimtranscripts of all hearingsand copies of all written.submissions made at, andsubsequent to thehearings are on file andavailable for examination at theCommission offices in Ottawa andWashington, D.C. The names of the persons who testified at the hearings are listed in Appendix G.

During the hearingsthe Commission emphasized khat the ~eferencewas limited to water qual.ity matters and that the only air quality aspects were those related to the direct impacts of atmospheric emissions on water quality in theBasin. Nevertheless, it. was clear from testimony in Scobey that the air qualityissue was importank to many of the witnesses.

?'he essenseand salient points of the testimony and wri.t.ten submissions aresummarized below.

"l__.".__"_l_lPUBLIC HEARINGS ON THE REFERENCEI._. TO THE """_-. COMMISSION

At theNovember, 1977 public hearing the Commission heard testimony from electedrepresentatives, private individuals, citizen groupsl farmers, ranchers,and the Indian tribes in the Basin, The majority of witnessesin Scobey requested a moratorium on the project until all relevantissues had been identified and solved, and stressed the need to incorporatethe air qualityissue into the study. Most witnessesbelieved water quantity and qualityand air qaality were inseparable,that a separate Reference to the IYC should he made, thatscrubbers should be installed at theplant and that an air treatyshould be negotiated. Other main areas of concern voiced by many witnesses were thestrong potential for adverseimpacts on theagricultural and 1.ivestock operations in the Basin due to increasedlevels of boronand TDS from theplant, and the fact thatany studies should havebeen completed before the power plant was built so as not to influence the data gathering process. The Commission was toldthe time frame for the study was inadequate, Some witnessesurged SPC to usethe best available technology in the design of theplant8s poll.uticum controls and the question of the safety of the dam was alsoraised, Several - 54 - witnessestestified that there was a thriving sports fisheryon the East Fork that wouldbe damaged. The need to ensurethat Article Iv of the Boundary Waters Treatywould not be violated was stressed. As during the Commission'sapportionment hearings Indian' representativesagain asserted their right to thefull natural flow of the Poplar Riverunder a treaty with the United States andthe WintersDoctrine. In addition they expressed concern for the impactsof atmospheric emissions on the Basin. Some witnessesnoted the potentialadverse impacts of the reservoir and dewatering activitieson the local groundwater resources andurged the Board to investigate this problem.

A spokesmanfor Environment Saskatchewan outlined the responsibilitiesand approach of the department towards environmental protection in the provinceand stressed the fact that eventhough the Poplar River and its tributaries were small, that did not make the water any less important to all thecitizens of the basin,and thatthe resource must be usedwisely. The Commission was advised that the provinceintended to cooperate fullyin providng all relevantinformation on the project. In summary, the witnessstated that the project was proceedingin full accordance withCanada's obligations under the Boundary Waters Treaty.

InRegina a representative of SPC spoke of the need to provide electrical energy to the people ofSaskatchewan as economically as possibleand in a technicallyand environmentally responsiblemanner. The Corporation stood ready to assist the Commissionand also believedthey would benefit from the results of the study.The statement spoke of the water qualityand hydrogeotechnical data gatheringprocess which had alreadybeen initiated for the project, the relevantexperience of the Corporation with Boundary Dam Reservoir at Estevan, the need to determine the actual uses of water downstreamand to consider the 40 year period of record,including drought years, in relation to water - 55 -

quality,and the plansof the Corporation with respect to reclamation of the mined areas. Insummary, SPC looked to the Commission to assess opinionsand conclusions on water qualityin light of factual data from all reliable sourcesand also indicated their intention to comply with Article IV ofthe Boundary' Waters Treaty. The Corporationrepresentatives at thehearing also clarified the number of unitsapproved and/or planned at Coronach at that time oneunit had beenapproved and a secondone planned and provided for shouldfurther studies show a secondunit desirable. Although the originalplant concept involved four 300 Megawatt unitsIupon further study it was highlyquestionable whether units three andfour would remain economically viable, although they would remainunder study.

TME SEPTEMBER. 1979 HEARINGS

After receipt of the Board's Report inJuly, 1979, the Commissiondistributed copies in the area andannounced the dates of public hearings to receivecomments as soon as possible. Public hearings were scheduledfor Scobey on September 10 andCoronach on September 11. Subsequent to the release of the report, however, requests were receivedfrom private individuals and public officials that the hearings be postponedbecause sufficient time to reviewthe report had notbeen allowed due to its late arrivaland its length and tech; ical complexityand because the hearing dates coincided withthe harvest season. The Commission decided to proceedwith the hearingson the understanding that further opportunity for public commentwould be made availableif this was foundnecessary.

Scobey Montana-

Most witnessesin.Scobey were veryconcerned that due to late receipt of t'he Board's Report inthe area andthe pressures of harvest time, insufficient time hadbeen allowed for thepublic to - 56 -

complete any detailed study of thereport and appendices. The majority ofMontana residentsrequested that the Commission schedule a furtherset of hearings and allow an extension of timeto present more detailedtestimony.

The Stateof Montana pointedto three majorimpacts discussed in the Board Report that would potentially be associated with the SPC development:increased Concentrations of total dissolvedsolids (TDS) which would adverselyaffect alfalfa yields, increasedconcentrations of boron, which would adverselyaffect alfalfa and barleyyields, and theproposed water quantity apportionment which would essentiallyeliminate the sports fishery in theEast Poplar and result in the loss of approximately one half of the duck population. .It was emphasized thatthe effects of TDS and boron on crop yields arenot fully understood, with available data on impactsbeing limited to alfalfa, oats and barley and relianceplaced largely onwork done by Eaton in the 1940's. Even though thewater quality objectives presented in the Board Report arethe best available, the State believed that they may not adequatelyprotect irrigated crop yields in Montana. It was consideredimperative, therefore, that research be initiatedto resolveoutstanding questions concerning the effects of boron and TDS on crops grown in thearea. Although Montana had participated in meetings with representatives of the Governmentsof Saskatchewan, Canada and theUnited States, and was awareof a commitment by SPC to mitigation in the form of a closedloop ash disposalsystem to significantlyreduce boron concentrations from thoseindicated in theBoard's Report, it was imperative in theState's view thatjoint monitoringsystems should be in place in advance of alloperations. The Statepointed out the possible double counting of benefits with respectto the apportioned flows and demand releases on theEast Poplar which were previouslyconsidered by thePoplar Task Force in balancingthe benefits and costs of water allocationto Montana and Saskatchewan.Serious concern was also expressedregarding the - 57 -

Board's recommendation that on the East Poplar a discharge of 20 3 m /s for a two-day period five years outof ten is required for the fishery, because under the apportionment recommendations this water would not be available,

The Province of Saskatchewan statedits belief that in dealing with the PoplarRiver project the Government had discharged its responsibilities by maintaining a close and cooperative relationship with the Government of Canada, by keeping the United States and Montana Governments fullyinformed of project planning, and by actively supporting the work of the Commission. The Province indicated that the design of the project had been substantially modified, at considerable expense,to meet the concerns identified in the IJC Interim Report to Governments,in particular the incorporation of a closed-loop ash handling system, lining ofthe ash lagoons and planned installation of an extensive monitoring network. The Province believed that with proper environmental safeguards the project should proceedincluding the construction of a second unit, and that there would be no risk of injury to health or property either in Saskatchewanor Montana. It was noted that with further monitoring and researcho if the results are suchas to indicate that there are matters that need further considerationand further mitigation, the Province would give considerationto these at that time.

The Provincial Minister responsiblefor the Saskatchewan Power Corporation stated thatthe project was of tremendous importance to the peopleof Saskatchewan. Both the development and wise use of electrical energy in the Province are requiredto develop Saskatchewan's resource potential. The Minister illustrated the manner in whichthe province is embarking on a ten year period of resource development unprecedentedin its history and which will produce demands on §PC's energy load from the residential and commercial sectors. The coal resource has great significance for - 58 - theProvince as resources available for energy development include 4.5 billiontons of economicallyusable lignite coal. It was also pointed out that energydevelopment is proceeding in such a way as to m.aximize thebenefits and minimize any adverseenvironmental impacts which may be associated with development. The M'inister briefedthe Commission on thepurpose of theCorporation and on its developrne~~tas an electrical utili.ty from the 1920's tothe present day, emphasizing that unlike some otherelectrical utilities, none of theelectricity produced by SPC is normallyexported. Whileany new generationproject may be expectedto result in some detrimental effects, it was theconsidered judgment ofthe Corporation that the project at Cororlach would provideoverall benefits which far outweigh any disadvantages.

The majority of public witnesses wanted it understood that their comments were based on a ratherquick reading of the Board Report and that;their total concerns may not havebeen expressed, which is why furtherhearings were required. Of thosewitnesses who had an opportunityto study thereport to some extent, many expressedconcern about the project's effects on thebiological resources of the EastPaplar, on thefarmers, ranchers and irrigators in theBasin who depend on thequantity and quality of surface and groundwatexsfor their livelihood, and on waterquality as it relates to watersupplies for municipal uses. Although most people who testifiedrecognized air quality was outsidethe scope of theCommission's investigation, concerns were repeatedlyexpressed about the impacts of atmosphericemissions from the power plant in Montana.

The Commission was told that there were many aspects of the boron and T'DS issue whichwere notsatisfactorily understood to enablemeaningful recommendations to bemade. It was maintained thatthe Board's proposed water quality objectives were inconsistent wi.th objectivesfor similar constituents in otherinternational - 59 - streams such as the Colorado and Souris Rivers. Monthly flow weighted or mean values were not appropriate,according to many witnesses, as the Poplar River Basin is in an area of extremes. The fact that baseline pre-project water quality data were practically non-existant was often cited as a critical omission in being able to determine the transboundary impacts of the project and the computer generated baseline values were insufficient for the study. Of more importance, in the minds of some witnesses, was the cutting off of better quality spring water due to the apportionment since traditionally some of this water has been diverted into local impoundments or "oxbows" along the r iver for flood irrigation in May, June and early July. In addition, the high spring flush was considered necessary to flush out accumulated salt from the soil. Several farmers wereparticularly concerned that more work had not been done by the Board to investigate the type of crops grown in the Basin and to relate crop yieldswith the variety of crops or the actual soil conditions in the Basin (including leaching fraction and soil pH) and predicted concentrations of boron and TDS from the operation of the power plant. Some witnesses noted the possible synergistic effectsof boron and TDS which might result in greater reductions in crop yields than would be predicted from a simple addition of separate impacts. Together with atmospheric fallout directly on the Basin, which wasnot studied by the Boardl further reductions in yields could be expected to occur. One witness stated research has indicated a carcinogenic hydrocarbon has been found in coal and inquired whether hydrocarbon testing is being carried aut,, All the witnesses in the Montana portion of the Basin believed the water quality objective levelsfor boron and TDS suggested by the Board were not sufficient to protect present crops, nor did the objectives provide a marginfor future crops to be grown which may be sensitive to boron and TDS. Some witnesses disagreed withthe Board's use of trace levels of boron as a basis for calculating yield reductions. They believed yield reductions should be based on a comparison with the maximum yield, rather than the yield at trace - 60 - levels. It was also noted that barley is a major crop in the Basin, even though it has not been irrigated traditionally on the East Poplar, which is the area most impacted by the power plant at Coronach, and that barley is important for crop rotation and diversification. The Commission was also told that if limits for horon and TDS are set too high, this will affect the ability of farmers to grow certain crops which, althoughpresently not profitable or may not even have been developed, could become important in the future. In this regard, reference was made to a new crop, waxy barley, which canbe used to produce syrups and as a sugar substitute.

All farmers maintained that any reduction in crop yields would come directly out.of their profit margins, whichthey could ill afford, and that if this occurred the power plant should be considered to have caused injury under the terms of the Boundary Waters Treaty and compensation in some form should be required. Some witnesses suggested SPC should construct a desalinisation plant on the East Poplar at the border to mitigate against high TDS levels, and post a bond or establish a specialfund which could be used towards compensation if damages were shown to occur. Many witnesses suggested a moratorium onthe project until these critical questions have been answered.

Testimony relating to the biological resources of the East Poplar was also received. The Commission was told that the northern pike and walleye that exist in the river depend on flows during April and May for spawning and egg incubation. Large flows are also required in the spring to retard the encroachment of emergent vegetation and maintain the open water and emergent areas critical to duck habitat on the East Fork. Under the terms of the proposed apportionment the losses of the biological resources in this stretch of the river wouildbe significant, even if Montana were to use its entire apportioned sharefor fish and wildlife purposes. - 61 -

Severalwitnesses expressed,concern for the effects of the project,including dewatering, on thegroundwater resources of the Basin. The Commission was toldthat people depend on natural springsfor stock watering and that a lowering of thewater table wouldbe unacceptable and would affectranchers who raise cattle. In addition,the reservoir could cause saline groundwater torise higher, which might increase the production of nativesalt grasses on which cattle cannot graze.

A spokesman forthe Sioux and AssiniboineTribes on the Fort Peck IndianReservation continued to assert their full rightto all thenatural flow of the PoplarRiver, undiminished in quality and quantity, under the terms of theWinters Doctrine. The Tribes also took the positionthat, irrespective of themagnitude of the WintersDoctrine, acceptable water quality at the northernboundary of thereservation is from 500-1000 mg/l TDS and 2 mg/l boron measured at any given moment in time, and that water quality in the rivershould not exceed historic water quality levels at the reservationboundaries. If acompromise is necessary,the spokesman submittedthat an equitableagreement wouldbe to establish numericalcriteria at the International Boundary in which the two countriesshare the level of degradation betweenthe historic water quality levels and the maximum acceptablewater quality degradation level.References were made in thestatement to precedents in the IJC Report on theGarrison Diversion project and the agreement between theUnited States and Mexico on theColorado River which recommended lower objectivesthan the Poplar Water Quality Board. The Tribesbelieved that proper mitigation should be provided by SPC at any cost. This opinion was voiced by others who presented testimonyas well.

An adviserto the Uses and Water QualityObjectives Committeeand the Board expressedconcern with some of the statements in theBoard's Report which werebased on his advice. He - 62 - maintainedthat his adviceconcerning the degree of yieldreduction that might takeplace for alfalfa with the use of 8 mg/l boron in thesoil water and thatthe relative importance ofboron toxicityto cropsversus TDS toxicity had been misinterpreted in theBoard's Report. The Commission was toldthat the relationships between leachingfraction, soil water and irrigation waterconcentrations werecomplex and of the need toconsider the additional effects of irrigation management practices,crop type and weather. It was stated, however, that to the degree that data was availableto support it, an objectivelevel of 5.5 mg/l boron in irrigation water is a reasonablelevel to avoid yield decreases in alfalfa CKOPS, takinginto account an adjustmentfor rainfall dilution effect and a leachingfraction of 0.3 in theBasin. With respectto TDS and the ColoradoRiver arrangement between the U.S. and Mexico, he noted thatthe agreement only addresses itself to an incrementalincrease in ColoradoRiver salinity of 120 ppm difference between thepoint of diversionfor the U.S. versus Mexico, and doesnot provide for a level of 1000 ppm as had been stated by some witnesses.

A member of the Uses and Water QualityObjectives Committee of the Board addressedthe Commission on severalaspects of the Board's and Committees'Reports including the fact that the Uses Report was not anunanimous document. Factorsthat were omitted in the study includedthe very limited number of plantspecies that had been investigated and theexperiments on which thetoxic levels to crops were based did notsufficiently reflect local field conditions orvarieties of crops. With thecombination of soils,climate, plantspecies and water thatpeople in theBasin are working with presently, it was emphasized thatconditions are marginal andany deterioration would incite damage. Regardingthe salinityissue, it was conceded that onecould successfuly irrigate with waterof 1000-1500 mg/l TDS, but that it would cost more to do it and the question then becomes who shouldbear any increasedcosts. - 63 -

The former Chairman of the Board of Inquiry establishedby the Government of Saskatchewan to inquire, in part, into the proposed second unit at Coronach, testified on the recommendations of the Board of Inquiry insofar as they related to the conclusions of the Poplar Board's Report. The spokesman drew the Commission's attention to the Inquiry's Report which concluded that acceptable standards and objectives for the East Poplar could be maintainedif suitable mitigation proceduresin reservoir management and design and construction of the ash lagoons wereimplemented.

A spokesman representing the United States Department of State did not comment on the substance of Board's the Report, but expressed appreciation to the Board for their excellent work under difficult conditions. Reference was made to the bilateral talks that had occurred during the past year between the United Statesand Canada, but it was stressed that these discussions wereheld for the purpose of exchanging informationon various aspects of the Poplar project and did not prejudge anyof the issues whichhad been referred to the Commission.

Coronach, Saskatchewan

All the witnesses livingin the Saskatchewn portion of the Basin gave their support to the project. The Minister of the Environment, speaking on behalf of the Province of Saskatchewan,and the Provincial Minister responsiblefor SPC both reiterated statements expressed previouslyin Scobey emphasizing theneed for energy in the Provinceto support the ongoing resource development and referred to the substantial modificationsin the design of the project which had been undertaken by SPC to meet environmental concerns downstream in Montana. It was alsopointed out that 70 percent of the potash produced in Saskatchewan is sold to farmers in the midwest statesso that the development at Coronach has some benefits to the agricultural community in the United States. The - 64 -

Commission was toldthat the decision to proceedwith the second unit at Coronachhad been postponed repeatedly to allow time forthe Commission'sinvestigations, but the Government of Saskatchewan expressed the need to come to a finaldecision in the very near future to meet the power requirementsanticipated by the winter of 1982-83.

Otherwitnesses also spoke ofthe importance of the Coronach project inmeeting the energy needs of the Province and the factthat the project hadbrought and would bring immense social, economicand recreational benefits to the people of Coronachand the surrounding area. It was contendedthat reservoirs must be constructed to make use of water in the Provinceand in particular to store water usedin the generation of electrical energy.The Commission was toldthat people inSaskatchewan believe the Province recognizes its responsibilitywith respect to theenvironment, and hasshown that no large project wouldbe built and operated until all effectson the environmentand the local communityhad been fullyassessed. Witnesses were confidentthat this plant would meet all Canadianand Saskatchewan requirements and based on the assurancesgiven by theProvincial Government to take all necessary precautionsand to continue to monitor water quantityand quality, the project should proceed.

Comparisonswith a similar power plant,the SPC Boundary Dam Reservoir at Estevan,Saskatchewan were also madeand in particularthe high quality water inthe reservoir was mentioned as well as theagricultural land in the area whichproduces grain and hay crops of excellentyield. Since that project has operated for almost 20 yearswithout detrimental effects witnessesquestioned why,with improved technology, there should be detrimentaleffects at CooksonReservoir. - 65 -

Severalwitnesses spoke ofthe naturally high boron and salinitycontent of the East Poplar Riverprior to anydevelopments at Coronachand of irrigation projects inthe Basin in Saskatchewan thathad never been implemented because reports showed the water was not of suitablequality for irrigation. Opinions were expressed that there neverreally was anygood fishing in the East Poplar Riveruntil they were placedin the reservoir, which now provides a sourceof fishing for a wide area includingnortheastern Monta.na.

With regard to mitigation to meet possibleenvironmental problems most witnesses were in:favour of having continuous monitoringand providing safeguards as required,but believed that largeamounts of money on controls should not be spent'unnecessarily or onthe wrong equipment, when there are manyunknowns.

A statementon behalf of the Government of Canada was submitted to theCommission outlining developments which had taken place regardingthe project withthe Government of the United States andthe State of Montana.The statement reiterated the Government's assurancesthat it wouldfully adhere to its obligationsunder the Boundary Waters Treatyand noted that such adherence had been made a conditionof the license issued to the SPC underthe International RiverImprovements Act. The Governmentstatement did notcomment directlyon the Board Report butmentioned that the development of water qualityobjectives for the transboundary stream, such as had beendone by the Board for the Poplar, is a conceptwhich has merit inprinciple and which could be an effective management tool. The Governmentof Canada summarized by indicating a beliefthat the nature of the project is suchthat its effectscan be handled through the applicationof appropriate mitigationand other measures and the institution of a monitoringprogram to ensure that any unforeseeneffects are recognizedand dealt with, should these ever arise. The Government remained of the view that on this basis the 600 megawattplant could be builtand operated so as not to violate the Boundary Waters Treaty. - 66 -

The GeneralManager of theSaskatchewan Power Corporation spoke on behalf of the Corporationand submitted new information to the Commission, based onrecently completed studies,which the Corporationbelieved indicated the currentdesign of the ash disposal systemwould be more thanadequate to meet theConcerns of the Commission. It was also established that neitherthe public nor the Board had had anopportuni,ty to review this informationand therefore the Board Report could notreflect this recent data, The Corporationoutlined three major considerations which were discussed ingreat detail in the report submitted to the Commission. These included a commitmentby SPC to proceed with a closed loop recirculating ash transportsystem to eliminateconcerns of pollutionin Cookson Reservoir by the ash slurry water being decanted back to the reservoir;further studies of the permeabilities ofthe ash lagoon base materials whichshowed that the underlying tills were much more imperviousthan was formerly believed;and the probabilitythat attenuation of boron in the ash water byunderlying materials in the soil shouldremove this problem as a sourceof concern for future water qualityin the East Poplar. The Corporation'sconsultants briefed the Commission on the revised ash disposalsystem and on the nature and expected seepage effects of the system.

Oneconsultant briefly outlined the physicalsetting of the plantand ancillary facilities andhighlighted the nature of the problem with regard to the ash lagoons,including siting, design, water balancesand scheduling of constructionand operation. It was also stressed thatwhile the presentation of the Corporation centeredaround TDS andboron, these parameters were certainlynot the onlyones evaluated, but rather were theones of most concern. The potentialenvironmental impacts of the ash disposal system were discussedtogether with a .summaryof the findings of sequential ash leaching tests. The tests showedboron in the recirculating system couldbuild up to as high as 50 mg/l,although concentrations are - 67 .- most likelyto be considerablylower, based on otheroperating experience. The consultant compared theresults of computer studies on TDS and boron concentrationsfor the East Poplar at the International Boundary with the long and short termwater quality objectivespresented in the Board Report. For theperiod May to September thepredicted maximum TDS valueover a 10 year rolling averageperiod was lessthan 1000 mg/l, and thethree month weighted mean rollingaverages for the period of recordnever exceeded the proposedobjective.

A discussion of thegroundwater regime and recent hydrogeologicalevaluations followed, with results of fieldtests andmodel calculationsestablishing a very low (lom7 cm/s range) permeability of thematerials underlying the ash lagoons. The permeability of thenative material which will form thebase of the lagoon itself,after scarifying and compacting, was predictedto be in the loy* cm/s range, The consultantalso described two differentseepage flaw scenarios from thelagoons which couldoccur depending on thepermeabilities which actuallyexist in thefield a groundwater mounding and non-mounding situation. A maximum estimatedseepage rate from thelagoon of 2 X/s, with probable values in therange of 0.5 to 1.0 l/s, was predicted in thereport which, together with anticipatedattenuation in theseepage zone and dilutionafforded in theseepage in the Empress gravellayer, should reduceboron levels at the border near background values.

A second consultantto SPC outlinedfurther evaluations of leakage from thelagoons and presentedthe results of studies carriedout during June and July 19'79 tothe Commission. After a re,viewof thepresent groundwater system, there was a presentation of waterlevel data, piezometric mapsand flow-netanalyses for the area under study which led to thedetailed explanation on the results of calculations of permeabilities of the EmpressGroup and overlyingglacial till, of Empress Group rechargerates from the - 68 - reservoir and overlying tills, and ofmagnitudes of groundwater flow beneaththe proposed ash lagoons. The major results of the study showed thatleakage froma total of threelagoons each with a 600 mm compacted till base was estimatedto be about 0.72 l/s, and that it couldtake from 30 to 75 yearsafter construction of the'lagoonsfor theleachate to appear as groundwater runoff in theEast Poplar River, and most likelynorth of theInternational Border. The dilutionratio of thepresent groundwater flow rate to theleachate flow rate was estimatedto bemore than 20 to 1, based on the above conditions.

A spokesman forthe SaskatchewanDepartment of the Environmentreviewed the history of theproject since 1972 noting the development had been.thoroughlyreviewed by Saskatchewan and Canadian regulatoryagencies and by two independentSaskatchewan Boardsof Inquiry,that the transboundary implications had been discussed in bilateralmeetings and that watersupply and water quality had been studied by technicalexperts operating under the Commission.

SaskatchewanEnvironment viewed the Board Reportas a sound,useful study. While agreeing in general with mostof the major findings in theBoard's Report, some reservations were expressed which included a generalbelief that the Board orthe Uses and Water Quality Objectives Committee did not give sufficient weightto the fact that seasonal and cyclical improvements in water quantity and quality result from reservoir impoundments on prairie streams. The limitations on usesresulting from existingwater quality was alsonoted, as well asthe fact that there is a limited recreationalfishery in thePoplar River System.Regarding the effects of theapportionment on biologicalresources, the Commission was told it was assumed thatthe apportionment was intendedto assureboth countries ofan equitableshare ofwater for its own use. In this part of theworld storage is requiredto make useof - 69 - snow-meltwater in thespring and such storageaffects the regime of any stream which in turn will have an effect on aquaticresources. It was noted thatzero flows were reported in theMiddle and West Poplar in thepast which,together with flows of less than l cfs on theEast Poplar, posed some naturalstress for aquatic resources in theBasin. It was alsothe view of theEnvironment spokesman that a flow release of 700 cfsfor a two day period in atleast five years of eachten year period would destroythe practical underpi.nnings of theCommission's apportionment recommendations. The Commission was thus urged tocarefully consider the offset measuresproposed in the BiologicalResources Committee Report. While some of theseoffset mitigating proposals were practical,others were not; howevery Saskatchewan officials were preparedto cooperate with U.S. agencies todetermine the feasibilities and costs of reasonableoffset proposals.

The spokesman suggestedthat significant and sustained irrigationalong the East Poplar would only be possiblebecause the reservoir is in place and if the recommended apportionment is in effect. It was alsosuggested that experienced irrigators would trade a small,speculative loss in yieldfor an assured supply of water when theyactually needed it, duringhot summer months. In this regardfurther research is desirableto determine the exact nature of croplosses, if any.Another important point emphasized in thestatement concerned the comprehensive surface and groundwater monitoringsystem required for the project as part of its approval.

The Commission was told that SaskatchewanEnvironment was preparedto participate in establishingwater quality objectivesat theborder and thatthe Uses and Water QualityObjectives Committee Report was a sound basis on which tobegin. The spokesman urgedthe Commission to reject an objective of 2 mg/l toprotect barley, since this crophas never been grown alongthe East Poplar in Mont.ana. Concerningmitigation to control Fife Lake overflows,several - 70 - controloptions were outlined with theintent of indicating this area needed further study. It was theposition of theDepartment thatthe latest SPC proposal, which had theDepartment's approval, shouldeliminate water quality concerns relating to high TDS and boron concentrations in the Montana portion of theBasin.

-THE OCTOBER, 1979 HEARINGS

As a result of theconcerns expressed during the first set of hearingsabout the need forfurther time to review the report and technicalappendices, the Commission scheduled a second set of public hearingsat Regina, Saskatchewan on October 15, 1979; and at Scobey, Montana on October 16 and 17.

Regina,Saskatchewan

In Regina, a presentation on behalf of SPC clarified the roles of the two consultants who hadmade statementsto the Commission atthe previous hearings in September. It was notedthat bothconsultants had proceededalong parallel paths using commonraw data but notnecessarily the same methodsof approach, yet in the finalanalysis good agreement was reached. One basicdifference between the two studiesoccurred as a result of thedecision to utilize a recirculatingash disposal system -- theoriginal three large (3 x 44 ha)ash lagoons were eliminated in favour of one large ash kag,oon (40 ha) and a small (12 ha)polishing pond. The results of thestudies by both consultants weresummarized as showing an estimatedseepage rate of about 0.5 l/s to a maximum of 2 l/s, with generalagreement of 0.5 l/s to 1 l/s for 52 ha area of ashlagoon and polishing pond.

Comments by otherwitnesses again supported the project, with concernbeing expressed over the long delays and disputes. The representative of the Governmentof Saskatchewan reiteratedthe Province'sdesire and willingnessto cooperate and toact in a - 71 - responsiblemanner regarding the Poplar project. It was pointedout once more, however, that a decisionon the secondunit at Coronach hadbeen postponed again, and that anyfurther delay would not be possible. It continued to bethe view of the Government that the nature of the project is suchthat it couldproceed to a'second unit,given certain measures would be undertaken, without risk of injury to health cr property, either inSaskatchewan or inthe United States. Referringonce again to the closedloop ash handling systemand the lining of the ash lagoons to minimizeconcentrations ofboron and TDS inthe East PoplarRiver, the Government maintained thatundertakings given and mitigation measures proposed by SPC wouldbe effective in meeting the concerns identified by the Board.

The spokesman for SaskatchewanEnvironment did not elaborateon his presentation in September but urged the Commission to examine the technical reports of theconsultants to SPC inthe contextof what had been proposed and what had been approved by the departmentwith respect to theash handling system. The approval issued to theCorporation requires the establishment of a very elaboratemonitoring system and specifies thatthe seepage rate from theash lagoons shall not exceed 2 l/s. TheCommission was told that thisapproval is for the initiallagoons and that if monitoring shows the seepage rate is greater than predicted, the Corporation would be obliged to implementmitigation measures, severalof which are available, to meet the terms of this approval.

Testimonyon behalf of the towncouncil of Coronach was verystrong in support of the project.The demand for electricity inthe Province was stressed as well as thefact that SPC is a crown corporation,owned by the people ofSaskatchewan and which has concerns for and is committed to the welfare of citizens of the Provinceand the Province's international obligations. Fishing and duckhunting have not historically been of any significance in the East Poplar according to thespokesman, nor has therebeen any - 72 - significant irrigation on the East Poplar on either side of the border, particularly for barley. Projected plans by the Fort Peck Indians for 20,000 irrigated acres by the year 2000 were also questioned. The apportionment recommendation did not appear to be overly generous to Canada, in the spokesman's view, considering that not more that 25% of the Basin is in Canada and that the East Poplar forms a small part of that area. Considering the recent improvements to the project announced by SPC and the intentto establish a continuous monitoring system, the town council maintained that reasonable precautionshad been taken and that the project should proceed.

A representative of the Three Corners Boundary Association, a group of northeast Montana farmers, ranchersand citizens, spoke of the damage to crops and to East Fork .fishery thatwould be caused by the project and urged that the development as it is planned also poses a health hazard with respect to stack emissions and fugitive dust, a violation of health standards for trace elements in water and high bacteria counts. Article IV of the Boundary Waters Treaty was cited, stating that health and property in Montana would not be protected unde.r 'the current SPC project.

At the Scohey hearings ranchers, farmersand irrigators living in the Montana portion of the Basin were unanimousin their belief that the SPC project at Goronach would have adverse effects for the area. Most comments were from people livingin the East Fork Subbasin, both above and below Scobey, although many witnesses spoke of their concerns with respectto the Middle and West Forks as well. The Board Report: was criticized for recommending TDS and boron levels that were significantly above predevelopment levelsand some witnesses suggested the report seemedto be more interested in satisfying the requirements ofSPC than the needs of the farmingand - 73 - ranchingindustry in Montana. Otherscontended the project would leadto a violation of Article IV of the BoundaryWaters Treaty.

Farmers and spokesmen for farm interestgroups that the project might affectvoiced several concerns regarding potential impacts on crops. The Commission was toldthat conditions for irrigation in thebasin are presently marginal and that any increase in pollutantconstituents, such as boron and TDS, would aggravate the problem and would constitute damage because of decreased yields.Witnesses also stated that provided water is available there is a largepotential for irrigation in theBasin, being a relatively new techniquefor the area due totechnology and availablecapital, and thatthe possibility of introducing new crops tothe area should not be precluded by settingobjectives that are too high ortoxic to several varieties of sensitivecrops sucKas oats, wheat and barley. A numberof witnessess.tated that, contrary to theBoard's Report, barley is amajor crop in theBasin, although perhapsnot as an irrigatedcrop on theEast Fork, and that irrigatedbarley typically yields two tothree times the acreage of non-irrigatedbarley. Providing the economics are right, farmers may want to grow barley in thefuture, either as a cashcrop or for forage.Others expressed concern for the effects of increased TDS on alfalfayields. With less water available forirrigation as a result of theapportionment, the leaching fraction would decrease which would make crops more toxicto these constituents. Some noted theirplans for increasing irrigated acreages had been curtailed because of theuncertainties associated with the power development north of theborder.

Most farmersalso believed the spring flood flows were importantto their operations to flush outthe soil and replenish localsmall impoundments or"oxbows", from which water was drawn the following months ,duringthe irrigation season. Thesereduced flowsI due tothe apportionment, were seenas a significant loss. One - 74 - witnessproposed there should be a 50/50 split on each individual streamcrossing the Border rather than the recommended apportionment.Also any possibledegredation should be split 50/50, Problems with thebaseline data from which impacts on crops could be assessed were cited,as well as the overall unce.rtainties surroundingthe toxic level for some cropsbearing in mind native soil conditions, and thevariety andnumber ofcuttings of crops. The Commission heard of the need for more researchinto these problems,particularly field studies with typicalBasin conditions, such researchto be funded by theenergy developers rather than the agriculturalsector.

A numberof witnesses were primarilyconcerned with air quality problemsassociated with theproject and relatedhealth effects. One witnessdisagreed with calculations in the Board Report that showed contributions of stackemissions and fugitive dust to waterquality in thereservoir were insignificant, and presented a series of assumptions and calculationsto indicate the Board'spredictions may havebeen overlyoptimistic. Some witnesses mentionedthe possible synergistic effects of deterioratedair and waterquality ,on crops. The need for an airquality Reference on theproject was alsoraised several times at the hearings.

Potential effects of theproject on thegroundwater resource in theBasin was seenas being very important to some people in thearea. Any increase in thesalinity level of thewater table due tothe presence of thereservoir would be intolerable,the Commission was told. In addition, mine dewateringactivities should be closelymonitored to ensure no negativeeffects are created by loweringwater tables south of the border.

Testimony on the effects of theproject and apportionment on thefishery and duck population of theEast Poplar was also heard.Residents were concerned with thestatements in the Board - 75 -

Reportthat with decreasedflows the quality of thefishery, already marginal, would deterioratedrastically, and thatthe duck population would suffersevere losses. The proponentsof the SPC project were called on tomitigate against these losses.

Many witnessesrequested a moratorium on theproject until all.impacts were more accurately known, and a carefulmonitoring of surface and groundwaterconditions before Unit 1 went on line. Suggestions were made that SPC shouldpost a bond to cover future damages 01: pay grants in lieu of taxesto cover the cost of additionalservices which could be required by thepeople in Montana.

A member of WIFE (Women Involved in Farm Economics) providedthe Commission with information on one of thenewest potentialcrops for the area -'- waxy barley. Recentresearch conducted at Montana StateUniversity was described on the use of waxy barleyfor making high-maltosesyrup as a substitute far corn syrup in various food and other products. It. was alsoreported that there is a potentialmarket in thearea to support a plant processing 30,000 bushels of waxy barley a day.

El.ected U.S. off ici.ais ortheir representatives raised several points with respect to the prQject and the Board's study. There was a lack of confidenceexpressed in thecomputer generated results in thereport and concernover the high levels of TDS, baron and SAR that were recommended by the Board asobjectives to be met atthe boundary.Other statements referred to the TDS levels in the Commission'sGarrison Report and in theagreement with Mexico on the ColoradoRiver. One spokesman expressedconcern that a precedent would be set by the IJC if it acceptedthe Board's Report by implying that somedamage downstream is acceptablewithout compensation. Any benefit/costanalysis in this case would not be validsince benefits are all in onecountry and negativeimpacts in theother. Questions concerning possible losses and the way in - 76 - which compensation couldbe managed were raised, including what body would determine when, howand to whom any compensationwould be payable. A comprehensive monitoring system was also considered mandatory.

The spokesman for the State of Montana requested the Commission to refer to the State's previous testimony at the September hearings. A further point raised in the testimony was the basic problem of uncertainties. The State recognized that despite all the best scientific efforts, absolute answersto all questions were not going to be provided, nor did the State expect the Commission to recommenda guarantee of no risk. The statement expressed the hope and expectation that the Commission would carefully consider the Board's recommendations particularlywith respect to boron, TDS and the proposed mitigation measures, carefully evaluate the future importance ofthe northeastern Montana agricultural industry, weigh the loss or reduction of a sports fishery and waterfowl habitat,and prepare recommendations that would meet the needs ofthe present without sacrificing the opportunities of the future.

The Commision alsoheard detailed testimony from Scobeyls medical officer concerningthe potential effects ofthe project on the town's municipal water supplies and related health effects. The testimony noted that Scobeyls water supply is exclusively groundwater for domestic and household use and that little mention was made in the report of possible contamination from uranium, found in the coal seam, whendewatering wells pumpedout into the reservoir. Other constituents requiring careful control to ensure no leakage into the East Poplar included molybdenum, selenium, chromium, arsenic and vanadium. Comparisons of State and Provincial recommended levels for various constituents with objectives recommended by the Board seemed to indicate the Board had recommended a moderate to severe declinein the quality of thewater - 77 -

used formunicipal purposes in Scobey. It was statedthat although some of thesevalues may be of littlesignificance for health purposes,based on thepresent state ofknowledge, they could become a problem in thefuture. In addition,while these constituents may notrequire any increasedtreatment, the potential exists for additionalexpense to Scobey toobtain potable water of equal qualityto what is presentlyavailable. It was furtheralleged in thestatement that this would be a breach of Article IV of the BoundaryWaters Treaty.

A spokesman forthe Fort Peck Sioux and AssiniboineTribes continuedto assert the open-endedwater rights of theTribes established by Treaty with theUnited States in 1888, and thatthey do not depend on a presentuse. The Commission was urged to seriously consider other 'international boundary standardsfor salinity(Garrison recommendations andUS/Mexico standard),to supportthe Minority Report of the Usesand Objectives Committee of theBoard, and toreject any objectivethat permits TDS levelsto exceed 1000 mg/l at any time.

Two membersof the Uses and Water Quality Objectives Committeeof the Board, aswell as a consultantto that Committee, addressedthe Commission on specifictechnical points raised during thehearings and in the Board Report. One of the Committee members reiterated his seriousreservations about the Board's Main Report, expressedpreviously at the Commission's hearings in September. The witness tookexception to several of thestatements in the Board Reportwhich referred to the effects ofboron and TDS on alfalfa and barley, and tothe lack of any discussion of theeffects of TDS, boron and SAR on crops such as wheat,safflower, faba bean, sunflower and drybean. Several apparent discrepancies were also noted.Other major shortcomings of thereport were thefailure to recognizecrop rotation as a usefulfarming practice, and the failureto recognize barley as an importantcrop in theBasin. - 78 -

These omissions should cast doubt on the valuethe of report and its judgments pertaining to agronomics, irrigation water quality and practical farming, the witness stated. The main failing was the inference in the Board's Reportof a philosophy that some damage to crops should be acceptable.

Another member of the Uses and Water Quality Objectives Committee presented a technical report entitled "PoplarRiver Boron and TDS Objectives" to the Commission. The report dealt with some of the comments of oneadviser to the Committee and with the assumptions made in developing the above objectivesand how, if you made assumptions whichhe considered realistic, one could derivea different set of objectives. He stated theBoard had been too conservative and recommended a level of 9 ppm boron in the soil water to prevent yield reductions in irrigated alfalfa. A lengthy literature review of available information onthe effects of boron to plants was also presented,including an analysis of the classic Ea ton study .

A consultant to the Uses and Water Quality Objectives Committee presented his understandingof the salinity issueand the international decisions with respectto the Colorado River, this being an allowed increase ofsalinity.between the last downstream point of diversion in the U.S. and the first point of diversionin Mexico of an increment of115 ppm, on an annual averagebasis. There is no objective level of1000 ppm as other witnesses claimed. The consultant also summarized his involvement withthe Committee and reviewed the recommendations whichhe had made in briefings, letters and telephone conversations. He reiterated the reasons for his disagreement with two areasin the Board Report,namely the conlusion that a boron level of 8 ppm would not cause losses of alfalfa yield of greater than 6%, and that under expected future irrigation conditions boron problemswould not be expected to be as significant as future TDS problems. He also summarized some of the worldwide experience with respect to salinityand the manner in which permissible TDS levels should be set. - 79 -

SUPPLEMENTARY SUBMISSIONS

After the public hearings were completed, the Commission also received further written submissions from some witnesseswho testified at the hearingson the boron and TDS issues. These written comments respondedto some of the testimony and statements made during the hearings, which the Commission indicatedwould more properly be addressed in supplementary submissions. - 80 -

CHAPTER VI

COMMISSION'S CONSIDERATIONS AND CONCLUSIONS

BASELINE WATER OUALITY

Natural factors affecting water qualityin the Basin are essentially the sameas those influencing thewater quality of similar prairie basins in this semi-arid region of Canadaand the United States. It is an area where water is generally scarce, and where the relatively low and extremely variable precipitation falling in the Basinis the primary source of thewater flowing in its rivers and streams. As a consequence, flow varies dramatically on a seasonal basis and from year-to-year, with peaks generally in late March,April or early May accountingfor about three-quarters of the total annual streamflow. Except during this spring runoff, the streamflows are maintained primarilyby groundwater. The Basin is also characterized by relatively low humidityand a very high rate of evaporation, averaging morethan 0.76 meters (two and one-half feet) annually. The Basin in Saskatchewan containsa number of internal non-contributing drainage areas,the largest and most important being the Fife Lake drainage area of about414 km 2 2 (160 mi ). The outlet from Fife Lake to Girard Creekis dammed, and historically overflow has occurredon average once everyten years, although overflows werenoted in both 1975 and 1976. Although there is little water quality information on Fife Lake,the water from this lake is generally of relatively poor quality.

As noted earlier, natural drainage inthe Poplar River Basin has been modified by the construction of numerous reservoirs both large and small. The largest is Cookson Reservoir, with a - 81 -

storage capacity of 41,166 dam3 (33,375 acre-feet). The three remaining principal reservoirs in the Basin, all in Saskatchewan, have a total storage capacity of only 2270 dam3 (1840 acre-feet).

Throughout the study the state of knowledge concerning present surface water quality has been an area of considerable concern to the Board and the Commission. Water quality measurements prior to 1975 are both sparse and fragmentary. Knowledge of water quality prior to any construction activities (i.e., prior to 1975) is important as a baseline or reference value against which to assess the water quality changes predicted to occur as a result of the SPC plant. Collection of water quality data in a comprehensive, systematic way did not begin until 1975, the year that construction of Morrison Dam began. .Hence, much of 1975 water quality data and all of the post-1975 data, while considerably improved over the pre-reservoir construction data, nevertheless reflect the influences of disturbances (i.e., East Fork construction activities) on the natural hydrologic regime in the East Fork Basin. As well, the water quality in the East Fork Basin in 1975 and following years was affected in the following ways: 1) impoundment of water began in 1976; 2) Fife Lake overflowed in both 1975 and 1976; and 3) water was pumped from the Hart Coal Seam into Girard Creek beginning in 1976 as a result of initiation of mine dewatering activities. The effects of these three factors will be most pronounced in the East Fork Basin, but will also persist to some degree downstreamfrom its confluence with the Middle Fork. These factors complicate considerably the determination of baseline water quality.

Measured Surface Water Quality

Most of the water quality data has been collected since 1974. These data are discussed in detail in Appendix A of the Board Report. Water quality data were evaluated at the locations indicated in Figure VI-1. The parameters considered were TDS, major - 82 -

MiddleFork at West Forkat International \-.- InternationalBoundary floundary r- , EastFork at international Boundary

0 EastFork nearScobey

West rork PoplarRiver near 13rtsdette @ near Scobey ." - -. ._" "_ North Boondory Fort Peck I R - i

L €GEND 0 Model Output Pomts

Power Plont E Mlne Slte -N-I 0

Pop1 ar River near Poplar MISSOURI RIVER

FigureVI-1 Schematic Diagram of PoplarRiver Basin and water^ Quali ty SamplingStations (Source: Surface Water Quali ty Report) - 83 - ions, nutrients (phosphorus and nitrogen), boron, dissolvedoxygen, pH, temperature, turbidity, selected trace metals and coliform bacteria. Some pesticide data were also availablefor the International Boundary stations. In this report the Commission has given priority to stations 1, 3, 8 and 12, which are downstream of the SPC project, while data from stations4, 7, 9 and 11 on the Middle and West Forks are used occasionally for comparative purposes.

The water quality parameters identifiedby the Board as being of particular significance were total dissolved solids(TDS), 1 boron and, to a lesser extent, the sodium adsorption ratio (SAR) . All three parameters could have significance in terms the of use of water for irrigation, the principal water use in the Basin. The available pre-reservoir measurements are summarized in TableVI-1. TDS concentrations varied froma median value of 445 mg/l in the spring period toa median value of942 mg/l in the winter period. Boron concentrations in the pre-reservoir period varied from a median value of1.05 mg/l in the springto 2.75 mg/l in the summer. Median measured SAR values ranged from 1.97 in the springto 4.60 in the autumn period. Total dissolved solids and boron concentrations are discussed .in more detail in the later section on boron and TDS. Because of the small number of measurements, the values may not adequately reflect pre-reservoir conditions.

~ ~~~ ~~ 'The sodium adsorption ratio (SAR) is a measure Of the proportion of sodium to calcium and magnesium. In the Board's investigation, the SAR + ++ ++ was calculatedwas as Na+ , where Na , Ca , Mg

are measured in milliequivalents. - 84 -

Table VI-1: Measured TDS, boron, SAR and flows in the East Fork at the International Boundaryprior to the closure of Morrison Dam

Sprin g2 SamplesSpring2 4041 4 Median 445 19.5 1.97 1.05 10% 135 0.82 90% 870 - 3.32 Summer 2 Samples 27 4 29 Med i an 775 6.0 4.54 2.75 10% 612 - 2.96 90% 1488 11.7 Autumn2 Samples 23 7 23 Media n 924 Median 3.4 4.60 2.04 10% 794 - 3.73 90% 1167 90% - 6.73

Sampl es 13 3 13 Winter3 2 13 Samples Median 942 Median 0.7 4.01 2.30 10% 758 - 3.44 90% 1132 - 6.06 lMedian mean daily flowfor the period of record. 2Spring - March, April and May; Summer - June, July and August; Autumn - September, October and November; Winter - December, January and February (Source: Surface Water Quality Report) - 85 -

The dominant cation and anion in the Basin surface waters were sodium and bicarbonate, respectively. Median chloride levels were low at most stations. Bicarbonate, sulphate and TDS concentrations varied seasonally throughout the Basin, although no similar variation for the other major ions was noted. The concentrations of the major ions in the East Forkat the International Boundary are summarizedin Table VI-2.

The highest nutrient concentrations occurred inthe spring and summer. Concentrations of dissolved oxygen often remained greater than 4 mg/l, although they have been observed to drop as low as 1 mg/l under ice cover in theWest Fork. Autumn levels were generally highest (median value of11.4 mg/l), while winter levels were lowest (median value of 6.3 mg/l). Surface waters were generally alkaline. Seasonal median pH values ranged from 7.6-8.6, with winter values lowest,and summer and autumn values highest. The median winterwater temperature was 0.5 0C, while the corresponding summer median temperature was 220 C. The highest median seasonal turbidity values were observed during the summer, possibly due to the abundance of algae. Nutrient, oxygen and pH conditions in the East Fork at the International Boundary are summarized in Table VI-3.

Trace metal data are relatively morescarce. Iron and manganese were the most abundant trace metals in the Basin with annual median values of0.4 for total iron and 0.05 for total manganese. In some of the samples, high dissolved mercury concentrations were observed,but the Board concluded that these high values were probably due to sample contamination. Samples of dissolved mercury fromthe East Fork atthe International Boundary were all below detection limits (TableVI-4). - 86 -

Table VI-2: Measured concentrations (mgbl) of major ions in the East Fork at the International Boundary priorto the closureof Morrison Dam

Bicarbonate Chloride Sulphate Calcium Magnesium Sodium

Spring Samples 41 42 40 42 42 41 Median 360 1.7 123 43 30 69 129 0.410% 129 25 18 10 19 90% 590 7.090 219 53 144 Summer Samples29 28 27 28 29 29 573 3.7Median 573 244 37 52 173 10% 483 0.6 145 26 38 110 90% 875 1649 540 63 451

Autm Samples 23 23 .23 23 23 23 Median 645 . 4.748 250 50 204 10% 585 0.1 194 32 43 159 90% 755 10.374 330 56 290

Winter Samples13 13 13 13 13 13 Median 715 4.4 258 81 50 185 10% 6 53 3.5 185 68 41 155 90% 833 6.394 310 55 27 5 (Source: Surface Water Quality Report) - 87 -

Table VI-3: Measured values for nutrients(mg/l) , oxygen (mg/l) , pH and temperature in the East Fork at the International Boundary prior to the closure of MorrisonDam

Total Total No3, No2 Temperature PhosphorusNitrogen Nitrogen Oxygen' pH oc

Spring Samples 40 4 36 - 42 - Median 0.12 1.30 - 0.14 8.0 7.8 0.6 10% 0.03 0.09 4.4 7.5 0.5 90% 0.28 0.26 10.2 8.4 12

Summer Samples 29 8 29 - 29 Median 0.13 1.67 0.06 9.1 8.6 22 10% 0.03 - 0.01 5.2 8.3 16 90% 0.33 0.13 11.0 8.9 24.5 Autm Samples 23 8 24 - 23 - Median 0.04 1.25 0.04 11.4 8.3 11.2 10% 0.01 0.01 10.2 7.9 1.5 90% 0.18 0.11 12.0 8.5 17.5 Winter Sanples 13 3 13 - 13 - Median 0.01 1.10 0.1 6.3 7.6 0.5 10% 0.01 0.01 6.0 7.4 0.5 90% 0.02 0.17 6.6 7.7 1.5

'The maximun aid minimun values are given for andoxygen temperature rather than the lo* and 90th percentiles. (Source: Surface Water QualityReport) - 88 -

Table VI-4: Measured concentrations (mg/l) of metals in the East Fork at the International Boundary Prior to the Closure of Morrisan Dam

Metal Samples 90 th2 Median , 10th

Aluminum: Dissolved 6 0.04 0.02 BDL mtal 10 8 BDL3 BDL Chranium: Dissolved 5 0.01 BDL BDL Wtal 9 0.01 0.01 BDL Manganese: Dissolved 5 0-20 0.07 0.02 Total 91 0.22 0.05

3BD~= belaw detection limit (Source: Surface Water Quality Report) - 89 -

Pesticide data are even more limited. Only four of the eight pesticides for which analysis were made were present at detectable concentrat-ions. The broadleaf herbicide 2,4-D occurred in the highest concentrations (up to 0.08 ug/l). Lindane and alpha BHC were found at maximum levels of 0.001 ug/l and 0.02 ug/l, respectively. Heptachlor was found in two samples at 0,003 ug/l levels.

For most stations, the median total coliform bacteria colony counts ranged from 34-40/100 ml. The median fecal coliform counts ranged from 20-30/100 ml. Highest median counts of total and fecal coliform bacteria (57/100 ml and 60/100 ml, respectively) occurred at the Poplar River near Poplar, Montana, while the lowest counts were recorded for.the West Fork'atthe International Boundary.

In general, the water quality in the surface waters in the Poplar River Basin is similar to that in other intermittent prairie streams. The relatively higher boron concentration in the eastern part of the Basin is perhaps the most atypical feature of the water quality in this system. Further discussion is limited to boron and TDS, the principal water quality concerns identified by the Board.

Total Dissolved Solidsand Boron in the Poplar River Basin

As indicated in the previous section, the pre-reservoir boron and TDS data are limited to a relatively few measurements. Because of the relative scarcity of pre-reservoir data, much use has been made of model-generated data to simulate historic baseline conditions and to predict future conditions. The measured values summarized in Table VI-1 do, however, provide a general perspective as to the concentrations that occurred prior to construction and provide one meansof assessing the accuracy of model-generated baseline water quality. - 90 -

Measured data from nearbyst,reams outside the Basin can also be used to provide a perspective of the appropriateness of the model-generated values. In October 1975 the U.S. Geological Survey established a network of nine data-collection stations on eight streams in east-central Montana in order to monitor water quality in several potential coal-mining areas. Although in a different region of the State, these data allow comparison withthe predicted boron and TDS concentrations for the Poplar Riverunder pre-reservoir conditions. These east-central Montana stations are all located in the area between the confluenceof the Missouri and Yellowstone Rivers, just east ofthe Montana-North Dakota border. The data for boron and TDS, collected during the first two years ofthe monitoring program, are summarized in Table VI-5. Boron concentrations varied from 0.06-1.2 mgyl, with the majority of the values in the range of about 0.1-1.0 mg/l. The mean TDS values varied from 1090 mg/l to 2560 mg/l while individual valuesranged from 160-4570 mg/l.

Table VI-5: Boron and TDS concentrations in nine east-central Montana streams, October1975-October 1977 Boron (mg/l) TDS (mg/l) # of # of Ana lyses Range Analyses Mean Range Mean Analyses Range Analyses

3 0.11-0.18 3 1090 628-1540 9 0.12-0.36 9 1570 433-2460 4 0.43-1.2 4 2200 1.180-3840 10 0.12-0.91 10 1910 528-4570 24 0.06-1.0 22 1200 160-2380 9 0.11-1.1 8 1220 212-2480 35 0.22-0.97 34 2560 1060-3370, 23 0.08-0.48 23 2080 531-2940 22 0.17-0.45 22 1090 382-1420 (Source: McKinley, P.W. 1979. Water quality of selected streams I_ in the local area of east-centralMontana. U.S. Geol. Surv. Water- Resources Investigations. 78-142.49 pp.)

Model-generated data for the "historic baseline" and "predevelopment" scenarios are summarizedbelow in Tables VI-6 and VI-7. The "historic baseline" is defined as the water quality with Table VI-6 Computed Predevelopment and Historic Baseline(1975) TDS Concentrations for Selected Sites in the Poplar River Basin

Concentration of Total Dissolved Solids (mg/L) STATION*** SCENARIO STATISTIC* Jan Feb Mar Apr May June July Aug Sep Oct Nov Oec

West Fork at Predevel opment mean ** ** 430 420 640 61 0 680 670 670 750 720 ** International Boundary Historic Baseline (1975) mean 430 490 640 600 680 670 670 750 720 percent change 0 17 0 (2) 0 0 0 0 0 West Fork Predevel opment mean 800 780 440 420610 650 720 820 800 820 820 81 0 near Bredette Historic Baseline (1975) mean 800 790 440 430610 660 730 780 800 81 0 820 81 0 percent change 0 1 0 202 1 (5) 0 (1 1 0 0 Middle Fork Predevelopment mean 760 710 530 530590 630 6JO 71 0 720 71 0 740 770 International Border Historic Baseline (1975) mean 760 710 590 540 590 630 670 710 720 71 0 740 770 percent change 0 0 11 20 0 0 0 0 0 0 OI Poplar River near Predevelopment mean 830 810 530 530630 730 940 960 1070 900 81 0 1050 u) Scobey Historic Baseline (1975) mean 1070 960 550 530 640 700 630 730 820 1040 870 1170 c" percent change 29 19 4 02(4) (33) (24) (23) 16 7 l1 I East Fork at Predevelopment mean 1420 1210 440 350 530 61 0 700 800 750 730 840 1070 International Boundary Historic Baseline (1975) mean 1450 1230 360 470 550 620 720 820 770 740 840 1080 percent change 2 2 (18) 34 4 2 3 3 3 1 0 1 East Fork Predevelopment mean 1270 1130 560 490640 700 780 860 820 800 870 1070 near Scobey Historic Baseline (1975) mean 1260 1130 540 510650 710 780 860 830 800 880 1080 percent change (1) 0 (4) 42 1 0 0 1 0 1 1 Poplar River Predevelopment mean 1230 1220 480 490670 750 840 970 1010 960 1000 1140 near Pop1 ar Historic Baseline (1975) mean 1230 1210 500 510690 790 960 1230 1200 980 1010 1150 percent change 0 (1) 4 43 5 14 27 19 2 1 1

* Parentheses indicate a decrease in TDS concentrations. This decrease shown during June, July,August and September for the PoplarRiver near Scobey is misleading. The model did not predict TDS values when streamflow was less than .0142 m3/s (0.5 cfs)even though TDS concentrations can be expected to be quite high at these low flow periods. Ignoring these presumably high concentrations results in the niisleading decreases in mean concentrations. ** Concentrations not predicted in these months. ***Station locations shownin Figure VI-1. _- Concentration of Boron (mg/i) - ,- - SiATIOfi*** SCENARIO SPATISTI&* JanMar Feb Apr May Jun July Aug Sap OctDec Hov " West Fork at Predevelopment mean .6 .8 .7 .8 .8 .8 .9 .8 ** Internationzl Boundary Historic Saseline (?975) mean .7 .8 .7 .8 .a .8 .9 .8 percent change 17 000 0 0 00 West Fork Predevelopment mean .5 .5 .2 .2 .4 .5 .6 .7 .6 .6 .7 .5 near Bredette Historic Baseline 1975) mean .5 .5 ..2 .2 .4 .5 .6, .7 .6 .7 .6 .5 percent change 0 000000 0 0 000 Middle Fork at Predevelopment mean 1.1 1.0 .7 .7 .E .9 1.0 1.0 1.0 1.0 1.1 1.1 International Boundary Historic Baseline 1975) mean 1.1 1.0 .8 .7 .8 .9 1.0 1.0 1.0 1.0 1.1 1.1 percent change 0 0 14 0000 0 0 000 Poplar River near Predevelopment mean 1.2 1.2 .7 .7 .9 1.1 1.4 1.5 1.7 1.4 1.2 1.6 Scobey Hi stori c Base1 i ne 1975 mean 1.6 1.4 .8 .7 .9 1.0 .9 1.0 1.2 1.5 1.3 1.8 percent change 33 17 14 0 0 (9) (36) (33) (29) 7 8 13 East Fork at Predevelopment mean .,7 2.4 2.8 .6 .9 1.1 1.3 1.5 1.4 1.4 1.6 2.1 International Boundary Historic Baseline 1975 mean .5 2.4 2.9 .8 1.0 1.1 1.3 1.6 1.4 1.4 1.6 2.1 percent change 4 0 (29) 33 11 00 6 0 000 East Fork near Predevelopment mean 2.5 2.2 1.0 .E 1.1 1.3 1.4 1.51.6 1.5 1.6 2.1 Smbey Historic Bas_eiine (1975) mean 2.4 2.2 .9 .9 1.2 1.3 1.4 1.6 1.5 1.5 1.6 2.1 percent change (4) 0 (10) 13900 0 0 000 Poplar River Predevelopment mean .5 1.3 1.3 .6 .8 .9 1.0 1.2 1.2 1.1 1.2 1.3 near Pop1 ar Historic Baseline (1975) mean .5 1.3 1.3 .6 .8 .9 .9 1.0 1.0 1.2 1.2 1.3 percent change 0 00 0 0 0 (10) (17) (17) 9 0 0

* Parenthesesindicate a decreasein Boron levels.Footnote to Table VI-6 also applies to this table. ** Concentrations not predicted for these months. *** Station locations shown 'in Figure VI-1. the 1975 level of usesof water in the Poplar River Basin, excluding any SPC developments. "Predevelopment" refers to conditions that existed before the area was settled, while "status quo" refers to the conditions existing with the1975 level of uses including Cookson Reservoir but without other uses associated withthe SPC project. In its discussion of computed boron and TDS concentrations, the Board presented dataas monthly mean values in it5 description of pre-reservoir water quality and as monthly median values in its assessment of the SPC plant impacts. The Commission has chosen to use monthly mean valueswhenever feasible.

The Tables showthat computed pre-reservoir boron levels were generally higher in the East Fork Basin than inthe rest of the Poplar River Basinand that concentrations generally decreasedat the International Boundary stations as one moves westward. The computed monthly meansfor boron ranged from about0.5-3 mg/l at the East Fork boundary stationand between 0.2-1 mg/l at the other boundary stations. The corresponding TDS values were about 400-1,400 mg/l at the East Fork boundary stationand about 400-800 mg/l at the other boundary stations. At the Poplar Rivernear Poplar, Montaria, computed pre-reservoir boron and TDS levels range between 0.5-1.3 mg/l and 500-1,200 mg/l, respectively. All concentrations were generally highest during low flow periodsand lowest during the spring runoff snowmeltperiod.

The most directway of assessing the'accuracy of model-generated data is to compare model-predicted values with measured values. In this process of model verification satisfactory agreement between predicted and measured values dependson the nature of the problem, the extentof available data andp probably most important, the purpose of the analysis. Perfect agreement between measured valuesand predicted values is virtually never achieved in environmental modeling. On the other hand, extreme accuracy is not required in many cases. Rather, trends and ranges may be sufficient to answer particular planning or management questions, Measured and predicted data setsfor the Poplar River - 94 -

Basin are examined within this latter perspective. The lack of a substantial pre-project database forces a greater reliance on model-genera ted data

The models used by the Board and its Committees are mass balance models based on the general assumption that the constituents will behave conservatively. This means that all of each constituent entering the surface OK groundwater of the Poplar River System will move downstream and khat none will be removed by physical, chemical or biological processes. This is a common water quality modeling approach. The basic model used to predict water quality is also based on the relationships between streamflow and boron and TDS concentrations,@ The model did not, however, predict concentrations 3 when streamflows were less than 0.0142 m /s (0.5 cfs). Consequently the mean predicted values illustrated in Tables VI-6 and VI-7 and in Figures VI-2 to VI-13 do not take into account low flow conditions.

AS part of the.Board's investigation the Surface Water Qua.lity Committee of the Board computed median monthly TDS values for the East'Fork at the International Boundary and for the Poplar River near Poplar, Montana. These computed values were based on a 42 yeas period of flow records, and 'TDS concentrations were calculated for each month having a mean flow in excess of 3 0.0142 m /s (0,5 cfs). These values were then compared with the median of the recorded instantaneous measure,mentstaken during the 1973-1975 period (Figures VI-2 and VI--3) The Committee also compared the computed monthly mean concentrationsbased on the flows from January 1976 to September 1977 with the instantaneous measurements taken during the same period (Figures VI-4 and VI-5). The Committee pointed out that. the predicted and measured values were not strictly comparable but nevertheless concluded that there was adequate agreementbetween measured and predicted values, and that the models would provide a reasonable predictionof water quality impacts in the Poplar River Basin. The Committee noted that - 95 - I

I500

1000 c \- 0 E u m n c- 500

0

Figure VI-2 Model Predictionsfor TDS Concent,rationsin the East Fork at the Internationdl Boundary Before Morrison Dam (x) Compared to Observed Historical Median Monthly Values (0) (Source: Surface Water Quali ty Report) I500

IO00 - \ 0, E e cn n I- 500

0 J F M A M J J A s 0 N D .- MONTH

Figure VI-3Model Predictionsfor TDS Concentrationsin the Poplar River near Poplar, Montana Before Morrison Dam (x) Compared with Observed Historical MedianMonthly Values [o) (Source:Surface WaterQual ity Report) - 96 -

7t"." ""

1976 1977 DATE F-iqure VI-4 Model Predictions for TDS Concentrations (x) in the East Fork at the International Boundary Compared with Observed Values (0) (Source : Surface Water Qual ity Report)

2000

1600

2130

" DATE

Figure VI-5 Model Predictions for TDS Concentrations (x) in the Poplar River near Poplar, Montana Compared with Observed Values (e) (Source: Surface Water Quality Report) - 97 -

""I_ " "_ "I"T It 1

""

0 L

JAN FEB MAR APR MAY JUL JUN AUG SEP OCT NOV DEC

Figure VI-6 COMPARISON OF MODELPREDICTED BORONAND T D S CONCENTRATIONS WITH CONCENTRATIONS MEASURED BETWEEN 1975 AND 1980 IN THE EAST FORK AT THE INTERNATIONAL BOUNDARY - 98 - 3.2

JAN T

Figure VI-7 COMPARISON OF MODELPREDICTED BORONAND T D S CONCENTRATIONS WITH CONCENTRATIONS MEASURED BETWEEN 1975 AND 1980 IN THE EAST FORK NEARSCOBEY - 99

JAN FEB JAN MARMAY APR JUN JUL AUG SEP OCT NOV DEC

Figure VI-8 COMPARISON OF MODELPREDICTED BORONAND T D S CONCENTRATIONS WITH CONCENTRATIONSMEASURED BETWEEN 1975 AND 1980 IN THE POPLARRIVER BELOW SCOBEY - 100 -

1,Predicted Monthly Mean Concentvation ___._____-_ "

"

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC "_ "_

I-."

Figure VI-9 COMPARISON OF MODEL PREDBCTEQBORON AND TDS CONCENTRATIONS WITH CONCENTRATIONS MEASURED BETWEEN 1975 AND 1980 IN THE POPLARRIVER NEAR POPLAR - 101 -

2000 - c I 800 * -

Figure Vi- 10 COMPARISON OF MODELPREDICTED BORONAND T D S CONCENTRATIONS WITH CONCENTRATIONSMEASURED BETWEEN 1975 AND 1980 IN THE MIDDLE FORK AT THEINTERNATIONAL BOUNDARY - 102 -

""1"- ;&Mea7 Conce tration "- 7 Percentile T

JAN FEE MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Figure VI--!! COMPARISON OF MODELPREDICTED BORONAND TDS CONCENTRATIONS WITH CONCENTRATIONSMEASURED BETWEEN 1975 AN.D 1980 IN THE MIDDLEFORK NEAR SCOBEY ..

- 103 -

3.0-

1:

Measured Instar taneousConcentration \

JAN FEE MAR APR MAY JUL JUN AUG SEP OCT NOV DEC

Figure VI- 12 COMPARISON OF MODEL PREDICTED BORONAND T D S CONCENTRATIONS WITH CONCENTRATIONSMEASURED BETWEEN 1975AND 1980 IN THE WEST FORK AT THEINTERNATIONAL BOUNDARY - 104 -

JUN JWL AUG SEP OCT NOV QEC

F'igUR?VI- 13 COMPARISON OF MODEL PREDICTED BORON AND T D S CONCENTRATIONS W8TH CONCENTRATIONS MEASURED BETWEEN 1975 AND 1980 IN THE WEST FORK NEARBREDETTE - 105 - the highest measuredTDS values at Poplar duringthe summer of 1977 were not predictedby the model because flowin the Poplar River at, 3 that time was less than 0.0142 m /s (0.5 cfs). The Committee also compared measured and predicted SAR values, but concluded that the model did not adequately predict thisparameter. A similar comparison was not carriedout for boron, presumably because the measured data were so sparse. It was assumed that boron behaved in the same conservative manneras TDS.

The Commission compared measured datafor the 1975 to 1979 period with model-generated dataat eight stationsin the Poplar River Basin (Figures VI-6 to VI-13). The data collected subsequent to October 1977 were not availableto the Water Quality Committee in its comparison of measuredand predicted boron and TDS concentrations. Because the measured data are essentially all from the post-reservoir period, the predicted values are taken from the scenario which includes Cookson Reservoirbut no power plant. Consequently, water quality at the two stations on the East Fork (Figures VI-6 and VI-7) and those on the main s'tem of the Poplalc River below the confluence with the East Fork (FiguresVI-8 and VI-9) is not "historic baseline." The concentrations at the four remaining stations (Figures VI-10, VI-11, VI-12 and VI-1.3) are for the same time periodbut are assumed'to be representative of baseline conditions since the flow regimes have beennot changed by Cookson Reservoir.

Measured values in FiguresVI-6 to VI-13 are the arithmetic means of the instantaneous measurements taken from1975 to 1979 inclusive. The ranges indicate the maximum and minimum values measured during the five yearperiod. Predicted values are based on streamflow records for the period from 1931 to 1974, using a "status quo'' scenario which includes Cookson Reservoirand 1975 uses exclusive of other project developments. Concentrations were computed for each monthof the period of record having a mean 106

monthly flow of 0,"Ot4~4In 3 /s (0.5 cis) or greater. The '" ' model~gen~.rat~~d v~~~u~s illustrated are the 10th percentiles, the " : " , 90th perce:ntil.e~! ~qd,~qnthly mean valu~s.

i': The measu~e,d monthly mean bo,~~'.iapd\.wDS concentrations for the 1975-1979 period in the East Fork:i;:at th,e International Boundary Cj ~, have genera,l1.Y b~en between 1.-2 mg/ltan~.OD-1,OOO mg/l, , ; respectively. During the same period instantaneous concentrations have varied from 0.12-3,1 mg/l fqr boro~ and from 95-1480 mg/l for - (; TDS." In the summer months the monthly mean bo~on and TDS , "~f?"o concentrations have varied from 1.4-2.0 mg/1 and from 900-l000mg,/l, 'l ,!7 (;~:;i if respectively. Further downstream in the Ea~t Fork near Scobey there ,,'; - " ! is a wider variation in the monthly mean boron and,TDS value-s. The 't.J,1 '!-

monthly ;: mea~s- fo~ boron . ~aQged f~om 0.7-2.4 m9/l over the year and from 1~6 to 2.2_mg/l during the swnmer months., Comparable values , for TDS were 500-1600 mg/l for the year and 800-1100 mg/1 during the summer. Instantaneous measur~ent~, va.ried from ,0.12-1.2 mg/'l for

" boron and from 100-2300 mg/1 for TDS.

; ",: ai' Seasonal variation in, ~ron and TDS conpentrations the poplar River below the confl~.Q-Ge with the East Fork (Figures VI-8 , ," "" I" ") t ' .." an~ Y1-'9) is more apparen~ ,,~hap ~t the East Fork., boundary station. " ,~, ,'~'

Boron.' :cc :,!:,r" concentrationsl"~ ar~ ge~~fJlly' somewhat lower at downstream locations,while,TDS concentrations in the Poplar River are similar w' ,~ to or, higher th~n ~n the upstream stations. Boron concentrations at the ,boundary s,~at+pp ?p tbe Middle Fork and farther downstream near Sc?gey ,~re ~~ne~rally lower than at, the boundary station on the East

Fork,. although. monthly" me~n cgncentrat,ions during the summer months are still in the 1.Q-l.75 mg/J. +~n

?tations on the Middle Fork and on the East Fork. Monthly mean TDS concentrations varied from 800-1100 mg/l during the summer months, approximately the same as at the other boundary stations. Fi.jrther downstream on the West Fork at Bredette, both boron and TDS concentrations were substantially less than comparable values at other stations in the system. Summer monthly mean concentrations varied from 0.55-0.7 mg/l €or boron and from 560-590 mg/l for TDS.

Fife Lake overflowshave also had an effect on Poplar River water quality. Fife Lake median monthly TDS levels ranged from L,500-2,500 mg/l. Measured boron values for 1977 were also high, varying from 3.1-5.1 mg/l. Overflows from Fife Lake have contributed to boron levels rising to as high as 3.1. mg/l ,at the East Fork boundary station. Water taken from the East Fork above its confluence with Girard Creek exhibited a range of 0.9-1.8 mg/l during the same period, indicating that Fife Lake can have a significant effect on East Fork water quality during the years it overflows.

Overall, the measured and predicted concentrations follow similar patterns. There does, however, appear to be a general tendency for the model to underestimate the concentration of both boron and TDS during low flow periods - especially during summer months. At some stations the mean measured summer values were typically 20, 30 or even 50 percent higher than the mean values predicted by the model. On the other hand, the model typically overestimated boron and TDS concentrations during the high flow spring months. Because most of the annual flow typically occurs during this high period, the flow-weighted annual concentrations.1. calculated Erom measured concentrations and 1975-1979 monthly mean flow records were

"-11 'Annual mass of constituent in streamflow divided by total annual Elow at the same location.

- 109 "

The Commission concludes that the apparent tendency to underestimate summer values and overestimate spring values is not significant enough to warrant altering the basic model predictions, alethough the tendencies should be kept in mind when assessing plant. impacts and when developing water quality objectives. The model-predicted values for baseline wat.er quality are used as the hasis for assessing the impact of various developments on water quality in the Poplar River Basin.

Groundwater

Groundwater quantity and quality in the Pop]-ar River area is described in det3il in Appendix B of the Board's Report and ir, discussed only briefly,here. Tn general, the natural groundwater the Poplar River study area was of marginalquality and often exceeded recommended or mandatory limits of state, provincia1. 9r federal governments for one or more parameters. Further, the observed concentrations in at least one well exceeded concentration criteria recommended by the Uses and Water Quality Objectives Committee for iron, manganese, nitrate, unionized ammonia, phenols, copper, fluoride, SAR, sulphate,zinc and selenium. High levels (~f molybdenum, which can cause a disease in cattle known as molybdenosis, were also noted in several wells. This has important implications since groundwater is the primary source of flows in the Poplar River Basin during low flow periods. Hence, its quality during such periods largely dictates the quality of surface waters available €or most uses, including irrigation.

The geological formations most directly involved in the Poplar River Basin groundwater circulation were sumrnarized in Figure 11-2. A generalized outline of the vertical variation in selected chemical constituents is given in Figure VI-14. Water in the Frenchman formation, the deepest formation, was generally a sodium - 110 - bicarbonate 'type. Mos,t water samples from this 1-ayercontained bor:,:>tn concentrationsabove 2 mg/l, and TDS levels in the range from 900--1.500mg/l. Relativelyhigh concentrations of molybdenumand E luor ide were al.so present.

The Ravenscragformation below the Hart Coal Seam exhibits a transition,containing water ranging from a relatively soft, sodiclm bicarbonatewater (similar to tile underlyingFrenchman i'orm.jtion water) to a hard calcium, magnesium, sulphate, bicarbonate water (similar to tire overlying Hart Coal Seam). Boron concentrations were in the order of 2 mg,/l.High phent~l concentrations were also noted.Wat'er in the Hart. Coal Seam itself was highin TDS, ranging from 1000-2000 mg,/l. Boron level,-; ranged from 1.5-2.6 rng/l.. Ir(>n, manganesL?, uraniumand radium-226 were also presen.tin relatively high levels. TheRavenscrag formation abovethe Illart Coal Seam was aLso high in TDS, varyingfrom 1000-2500 mg/l. The samples from thisformation indicated a hard calcium, magnesium,sulphate, bicarbonate type water. High values were also noted for uranium,selenium and nitrate in one sample. The boron l.evel:; seldomexceeded 2 mg/l. The waterquality in these layers is importantsince the water pumped from the Hart Coal Seam, as a result of mine dewateringactivities, will bedischarged to the Cookson Reservoir, As noted above, this water will generallyhave boronlevels around 2 mgjl and TDS levels between 1000-2000 mg/l.

'The surface deposits generallyhave low boron and 'rDS levels. The groundwater in this layer can be highly variable, however, and canhave high boron and TUS levels where the surface Layers receive groundwater from underlyingformations. - 111 -

n

" L. ci._

Y L li

wo 5.L "- 1. 1. 2 -

-_ li4 -

P1-Y mN r(N N

II

‘“ -rJ

m Ob .rr r- w I” P m N N N R N

d am W om rl rlm d

(\i 00 m -? a

In 4 3 I9 TABLE VI-Ob

rnCIPAL m1c

Subtokals Saskatchewan WestForkShbasin 0 46 25 0 0 230 301 Elidle Fork Subsin 0 136 0 * 52 0 18s East Fork Subbasin ' 36 376 137 * 85 390 1024

colm Subtotals 558 36 162 * 6 137 20 1513 Mon tam Exclusive oE Reservaticn West Fork Subbasin 0 38 1 331 630 90 1432 Middle Fork Suthsin 0 122 73 460 772 1427 FoplarRiver Stbbasin 350 334 306 55 1 20 48 3589 East Fork Subsin 0 105 852 0 147 1104 . P colm Subtotals 350 942 156 2 164 1 3057 7552 P Ln

mKt Peck Indian Reservation I West Fork Subbasin 0 88 39 0 0 121 Foplac River Subbasin 0 802 260 222 519 1003

Colum Subtotals 0 890 299 222 519 - 19 30

Grad mtals 386 2390 2023 1063 3513 620 18 995

Total Projected Future WaterUses in the Foplar RiverBasin: Saskatchewan (cubic decametr9.s)

Irriga tion Reservoir Irrigation mtal Use Municipal Dxnestic Water Spreading Full Service Evaporation Industrial Wildlife By Subbasin 1985 2000 1985 2000 1985 2000 1985 2000 1985 2000 1985 2000 1985 2000 1985 200G

West Fork Subsin 0 0 7272 43 43123 123 284 284 0 0 0 0 522 522

Middle Fork Subbasin 0 411 213 213 0 90 0 90 0 4439 u 3133 185 185 488 8471

East Fork Subsin 185391 237588 588 237 147147 4439 4439 268b 2688 1851858469 8675

Colm Subtotals 185 802 873873 280 280 360 3605821 26889162 4723 370 370 176689479 .I ua c- *w P N '9 w 4 NOW

w N 4

N W w cn rr

N +- k-" i- w P-43 N LO w 0

1-4 W a m N W 0 CJ 0 000

4 ww P QIQ\W 1-4 aow 4 uoo

S - 11.9 -

Montana

Projections of E Iuture uses in Montana, excllJsive of the Fort Peck IndianReservation, were based on theassumption that- the increased use patkernobserved over the past 15 years would cuntinue i.n the future. For theFort Peck Reservation,projections were based upon infc:,rmati,on provided by theTribes. The estimates were: n=rt 'iimited tca amounts of waterthat wouldbe av3i.l.ableunder the appor t ionment: recommended by the Commission.

'Tables VI-loa and 10b and TablesVI-lla and Llb summarize the uses and Water QualityObjectives Committee projections of future uses in Montana, exclusive of and also including theFort ~eckIndian Reservation respectively. Projections of future rr~unicipalwater use by the town ofScobey assumed both a declining and increasingpopulation, based on pastrecords and possibLepotash development,respectively. Future use projections for stock watering and reservoirevaporation were based ona trendanalysis. A Montana Department of NaturalResources and Conservation survey of landsnot yet irrigated (excluding the Reservation) was used to projectfuture irrigation use in Montana. The irrigableland was estimatedto be:

Class 1 land(best suited for crops) 0 Class 2 land 23,976 ha ( 59,200 acres) Class 3 land 94,770 ha (234,000 acres) (Lands below Class 3 arenot considered irrigable)

As notedabove, irrigation practices vary throughout. the Basin. The methodsrange from springwater spreading to full serviceirrigation, which includessprinkle irrigation and flood irrigation by eithergravity or pumping.

In thefuture, as a result of Cookson ReSeKVOir, thespring floods on theEast Fork will be considerablyreduced, resulting in

TABLE VI-loa

Total ProjectedFuture Irrigaticm in Montana, Bclusive oE the Fort Peck Indian Reservation (1985 and 2000)

Watersprecding SprinklingFlcdinq 2000 1985 2000 1985 2000 1985 2000 19851985 2000 3 3 3 dam3 3 dam3 dam dam dam darn hKtares req'd hectaresreq'd hectares req'd hectares req'd hectares req'd hectares req'd

West Fork Shbasin 57 2020 28 4403 1174 719 168 1133 446 430 124 936 i

N Middle Fork Subsin 221 104487 138 2303 340 981151 140 303 190 1644 e

Wlar River Subbasin 154 1088263 428 668 3OL8 390 26111070 344 2496 356

462 1171 530 1344 0 0 0 0 38 291 91 692

1096 2779 1555 39401555 2779 1096 4627698 io99 3233 577 8034376 6090

dam req'd3 = cubic decametres of mter required. TABLE VI-lob %tal Projected Future Irrigaticn in Mntana, Exclusive of the Fort Peck IndianReservation (1985 and 2000)

Waterspreading Sprinkling Flooding 1985 2000 1985 2000 1985 2000 1985 2000 1985 2000 1985 I acres AE' req'dacres AF req'dacres AF' req'd acres AF req'd acres AF' req'd acres AF req'd w N West Fork Subbasin 1L02 583 700 759 305 349 140 2287 919994 952 414 N I Middle Fork Subbasin 373 179 215 1771 470 847 3403 I11932 840 7963 46

Poplar River Subbasin 88 1057 542 650 2448 983 2118 850 2024 2 880 874 380

East Fork Subsin 10901308 950 1140 0 0 0 0 2 95 36 56 225 1

Colm Subtotals 32023840 2254 2705 49391983 355011.40 1425 6243 2714 2622

AF req'd = acre-feet water required. TABLE VI-lla Total Projected Future Uses in the poplar River Basin Fort Peck Indian Reservation (cubic decametres)

Danestic Irrigation Reservoir Waterspread Full Service Evapor3tion 1985 2000 1985 2000 1985 2000 1985 2000

West Fork Subbasin 109 109 48 . 48 0 0 0 0 poplar River Subbasin 9 89 989 321 321 34 682 68 784 60716071

Column Subtotals 1098 890 36 9 36 9 34 682 68 784 60716071 I

TABLE VI-llb Total Project& Future Usesin the Poplar River Basin Fort Peck Indian Reservation (acre feet)

Danest Lc Irrigation Reservoir Waterspread FullEvaporation Service 1985 2000 1985 2000 1985 2000 1985 2000

West Fork Subbasin 88 88 39 39 0 0 0 0 poplar River Subbasin 802 802 260 260 28 128 55 786 4924 4924

Column Subtotals 890 890 299 299 28 12324 55 49786 24 49 - 124 -

It is importantto note that the av3ilable land for irrigation is notthe limiting factor when projectingfuture irrigation.Rather, irrigation will be limited by waterquantity and probably by waterquality. In addition,fu.ture economic conditions will likelydictate future irrigation patterns and the specificcrops grown in thePoplar River Basin. Further, the actual rate of increase in bothwater spreading and full service irrigation, whichhas increased steadily since the early 19601s, may be lowerthan the projected rate due in partto uncertainty on the part of irrigatorsregarding the impact of theapportionment and the SPC power plant,particularly on theEast Fork. Finally, while such considerations as soilchemistry, texture and depth,lay of theland and distance f rom watersources, as well as other factors, were takeninto account in estimatingirrigable lands and future use requirementsfor irrigation by thetechnical committees, a precise determination of thetypes of cropsthat could or wouldbe grown on theselands was not made by theBoard. However, it is known that theprincipal irrigated crop in theBasin is alfalfa. This will likely be thecase in thefuture as well,although other possibilitiesshould not be excluded.Other crops that either have been,or are likely to be irrigated in thefuture are barley, wheat, oats,potatoes and sunflowers. In addition,the Commission was informed at the public hearings thatanother type of barley, waxy barley, was beingintroduced in theBasin. It was suggestedthat waxy barley, whichcan be used toproduce syrup, could possibly become an importantcrop in theBasin.

Futureindustrial use in the Montana portion of theBasin is relatedto the vast potash and lignitecoal reserves in the area.There is potential€or a potashdevelopment near Scobey in the EastFork Basin, which would require up to 8,650 dam 3 (7,000 acre-feet)of water. However, thepossible impacts of such a development on waterquality and water uses were notevaluated by theBoard. Coal deposits are present in thearea, but no estimate - 125 - ofreserves has been made. In addition,the feasibility of developingthese reserves has not been investigatedto date.

Plansexist to irrigate 4,050 ha (10,000 acres) by 1985, and an additional 4,050 ha (10,000 acres) by theyear 2000 on the Fort Peck IndianReservation, on landsprimarily betweenthe Poplar River and Big Muddy CreekBasins. Currently the lands are intended to be used to grow alfalfa. In addition,the Sioux and Assiniboine tribes have assertedthat under theWinters Doctrine the full natural flow of thePoplar River is reservedfor them forpresent. and futureuses. As the Commission stated in its Apportionment Report(p. 54), "The Commission is not the proper forum forthe determination of thesetheories and claims,although the needs of those making the claims were given full consideration by the Commission in assessingfuture needs in theBasin. In general,the Commission viewsthe issue of waterrights as onebetween the individualclaiming the right and theappropriate governmental body."

The Commission concludesthat, to t.he extentwater is available, the projections of futureuses of water in theBasin are reasonable;however, the Commission recognizesthat with respect to agriculturaluses, the future acreages of specificcrops cannot be predicted with precision.

WATER QUALITY"" REQUIREMENTS FOR USES IN THE POPLAR RIVER BASIN - "_ "

Existing and reasonablyforeseeable water uses in the PoplarRiver Basin were discussed in previoussections. Based on theavailable data, the Commission concurs with theconclusion of the Board that most types of non-irrigationwater use in Montana (domestic,municipal, industrial, and fish and wildlife) are generallynot restricted by the waterquality existing prior to or following construction of Morrison Dam. Further, the Commission is notaware of any substantiveevidence that non-irrigation uses will - 126 - be affected by changes in thewater quality projected to occur in thefuture as a result of the SPC project.

A possibleexception is the level of mercuryaccumulated in fish. Mercury levelsin the flesh of adultwalleye from Cookson Reservoirhave been found to be about 1 mg/g (determined on a wet weight basis), which is theUnited States standard and is twicethe Canadianstandard. The Governmentof Saskatchewanhas recommended thatthe fish from this reservoirnot be consumed by humans. Recent literature on thesubject indicates that elevated mercury levels in fish fromnewly-flooded reservoirs is a common, though relatively transitory phenomenon, althoughagricultural and industrialsources couldalso be contributingfactors in this case.Other elements, suchas selenium, molybdenum and uranium,are also present in relatively high I-evels, 'but arenot currently expected to affect fur ture uses.

For irrigation uses, evidenceprovided by the Board indicatesthat the natural concentrations of boron in waterused for irrigation may already limit thegrowth of barley, a crop which is sensitiveto elevated boron levels. In addition, at times the naturalconcentration of TDS may exceedlevels optimal for alfalfa production. Most of theanticipated problems are associated with irrigationuses. Accordingly, the discussion in thefo.llowing sectionfocuses on theirrigation issue.

"Toxicity"as used in this reportrefers to reducedcrop yields,relative to the yield which occurs in the presenceof trace levels in irrigationor soil water. Toxicity can also be expressed in termsof physiological symptoms, such as leaftip burnor discolorations. However, yieldreductions were considered to bea more direct measure of impact on wateruses and are the criteria used in this reportto assess the toxicity levels of boron and TDS. Irrigationwater refers to the water applied to the fields, while soil waterrefers to the water percolating down throughthe root zoneof thecrops. - 127 -

Toxicity of Boron" in -Irrigation Water

The scienti€ic Literature contains considerable information on boron toxicity. It can usually be correlated wi.th the boron concentration in plant tissue, and plant uptake can usually be related to specific field or experimental conditions. It is apparent that while its exact metabolic role is unclear, boron is an essential plant micronutrient. It is also clear, however, that there is often a very narrow range between optimaland toxic amounts. Concentrations as low as 0.5 mg/l boron in irrigation water may be harmful to certain crops. In other cases, optimal boron concentrations maybe considerably higher than this level.

Several factors can affectthe precise impact that boron will have on specific crops in a given area. Principal factors include soil acidity (pH), SAR,precipitation, the period of irrigation, the variety of crops, the leaching fraction and soil attenuation. The leaching fraction is the portion of the irrigation water which is not used by the plant as the water percolates down through the root zone. Soil attenuation refers to the ability of soils to chemically bind or adsorb a substance so that the substance is effectively neutralized or rendered harmless.

The exact levels of boron which are toxicto crops depend on a number of interrelated factors, and boron toxicity occurs most commonly in arid or serni-arid regions. The Board concluded that natural boron concentrationsin most parts of the Basin were probably higher than desiredfor optimal growth of barley.

1 The Board cited a 1944 paper by Dr. F. M. Eaton , and subsequent consultation withDr. J. D. Rhoades of the U.S. Department of Agriculture Salinity Laboratory, Riverside, lEaton, F. M. 1944. Deficiency, Toxicity and Accumulation of Boron in Plants. Jour. Agric. Res. 69(6):237-277. - 128 -

California, as the principal sources of information for its analyses concerning boron. In an extensive series of tests conducted during the period from 1929 to 1934, Eaton compared the boron requirements and tolerances of 58 plant varieties. The tests were conducted out-of-doors in California and the test beds contained sand satturated with six different solutions of boron (trace level., l mg/l, 5 mg/l, 10 mg/l, 15 mg/l and 25 my/l). Because much of the debate at the public hearings concerning boron toxicity hinged on Eaton's experiments, pertinent data are extracted from his 1944 paper and arc? summarized below in Table VI-12. The Table illustrates how different plant species react to various boron concentrations. Levels that are toxic for one species, such as barley, may act as a growth stimulant to other species such asalfalfa or sweet clover.

The Board also made use of a model developed in part by Dr. Rhoades to aid in the Board's predictions of the effects of several concentrations of boron and TDS i:? irrigation water on irrigated crops. The model, originally developed to predict saLinity, incorporates mass balance techniques to predict the degree to which conservative constitutents will be concentrated as the irrigation water, in which they are carried, percolates down through the root zone. The model assumes that the plant. takes up 40 percent of the water in the upper quarter of the root zone, 30 percent in the 2nd quarter, 20 percent in the 3rd quarter and 10 percent of the lower quarter. The degrees by which conservative constituents will be concentrated in the soil water, as predicted by the model for various leaching fractions, are summarized in Table VI-13. The model predicts that the highest concentration factors occur when the leaching fractions are the lowest, e.g., when the leaching fraction is 0.5, the average concentration factor is 1.53; when the leaching fraction i.s 0.05, the concentration factor is 5.5'7. The model predicts that for a leaching fraction of 0.3, which the Board accepted as a reasonable estimate for the region, the average boron and TDS concentration in the soil water will be approximately double that in the irrigation - 129 -

Table VI-12: The Effect of Boron Concentrations on the Yield of SelectedPlant Species (expressed as dryweight (gm) PerTreatment).

-. -. "" " Boron Concentration In TestSOlUEii-K<7i-j- - """""-.- Test Number Plant Part.- Trace 1 5 10 15 25 " - .-~- - - Alfalfa 47 leaves 79 70 73 85 77* 42 47 other 197 209 221 237 195* 102 48 stems & leaves 125 133 127 113 -151* 88 49 stems & leaves 31 55 -59 38 35" 26 SweetClover 62 leaves 34 60 79 65* 54 64 62 other 64 100 -'132 97" 102 1.0 3 Barley 20 grain -102 90 65* 64 21 19 20 other -283 238 169* 154 112 71 Oats 43 grain 45 33 64* 35 23 9 43 other 234 280 -303" 217 16 7 86 SugarBeets 65 roots 44 42 66 65 50* 50 roots 174 2-42 192" 217 207 66 35 ~ 67 roots 51 Lao 223 151* -265 215 68 roots 40 54 67 ._93" 71 85 Potato 34 leaves 139 131" 111 -145 78 57 34 .tubers 591 796* 713 599 490 177 "

I I_

Underlinedvalues indicate maximum yieldswhile the asterisk (*) indicates the lowestconcentration at which visible signs of boron toxicity were detected.Data from Eaton, 1944. - 130 -

water. The Commission has accepted that this doubling of concentration will applyin the Poplar River Basin, although field data from other studies show that boron concentrations in soil water can be higher or lower than the concentrations in irrigation water.

Table VI-13: Average Relative Concentration Factors for Soil. Water Compared to Irrigation Water

_"""" _"""" ""l_""l".l" Concentration Factor

Leaching Fraction - """ -. Root Zone Interval 0.05 0 1 0.2 0.3 0.4 0.5 " " - . .""""."_"

0-1/4 1.30 1.28 1.23 1.19 1.16 1.12 1/4-1/2 2.32 2.1.3 1.87 1.67 1.52 1.40 1/2-3/4 5.09 3.98 2.92 2.33 1.94 1.68 7.63 4.28 3.01 2.33 1.91 3/4-4/4 _"__. 13.57 "" ""tl."-."--

Linear Averase for Entire Root Zone

0-4/4 3.75 5.57 2.581.74 2.05 1.53 "- " _I ."I_"- - (Source: letter from Dr. J.D. Rhoades to IJC, September 19, 1979)

The Board did not recommend a specific boron water quality objective for the International Boundary. Rather, based upon its study, the Board advised the Commission concerning boron levels for the protection of selected crops.

The Board suggested that a concentration of 0.5 mg/l boron in irrigation water was an acceptable upper limit in order to avoid any reductions in barley yields. Since historic baseline boron concentrations during the irrigation season were already well above this value, the Board suggested that, "An International Boundary water quality objective for boron necessary to protect barley irrigated in the East Poplar River Basin betweenthe International Boundary and the confluence withthe Poplar River from further yield - 131 -

reductions is thereforethe natural concentration (about 2 mg/l) .'I With respectto alfalfa the Board notedthat boron concentrations foroptimal alfalfa yields were considerablyhigher than those €or barley and suggested a maximum value of 5.5 mg/l boron in irrigation wateras the guideline for alfalfa crop protection. However, since no alfalfa is currentlyirrigated immediately south of the Boundary the Board concluded, "The International Boundary objectivefor boron toprevent yield reductions of irrigatedalfalfa between the International Boundary and theconfluence of the East Poplar and PoplarRivers, about 26 ha (65 ac), in theirrigation season is 6 mg/l .I'

Dr. Rhoades suggestedthe concentrations listed in Table VI-14 as critical boron levels which would notproduce crop yield reductions. He pointed'out that these levels werebased ona presumed leachingfraction of 0.3 and thatthe dilution effects of precipitation were notincluded. In suggestingthese levels, he was carefulto emphasize thatthey wereof a provisionalnature and that sitespecific informtion could well influence the choice of appropriatelevels. Rhoadesbased his valuesprimarily on the toxicitytests reported by Eaton (1944) and theconcentration factorspredicted in Table VI-13. In the case of alfalfa,the principalirrigated crop in theBasin, he chosethe results of test #49 (Table VI-12) asthe most appropriatetoxicity data. The Commission notesthat the use of theresults of tests #47 or#48 would have leadto different estimates of critical boron concentrations.

Table VI-14: Critical Boron Concentrations (mg/l) forVarious Crops

" Crop Soil Water " ~ Irrlgatlon Water " barley 1 0.5 wheat 1 0.5 oats 5 2.5 corn 5 2.5 al.f alf a 8 4 (Source:letter fromDr. J.D. Rhoades to IJC, September 19, 1979) - 132 -

The Board reportedthat the Water Uses and Water Quality Objectives Committee had "great difficuLty in determiningcriteria for developingboron requirements for irrigation", and the Board concludedthat the scientific literature provided little guidance forsetting acceptable boron levels. The Committee did, however, estimatebarley yields that could be expectedalong different stretches of thesystem downstreamof thePoplar River Project, basedprimarily on Eaton's (1944) report.Yield reductions in bushelsper acre for several boronconcentrat.ions in theEast Fork atthe International Boundarywere calculated from datapresented in theCommittee's Report and are summarizedbelow in Table VI-15.

Table VI-15: PredictedPercent Reduction in BarLey Yields for Several Boron Concentrations in theEast Fork at theInter.nationa1 Soundary.

-~"_-I- "._ " Boron ConcentratioqgTlT ." Sub-basin 1.0 1.5 2.0 2.5 4.0 " __" .""""""""- East Fork 7.5% 13.8% 17.5% 21.3% 35%

PoplarRiver to Fort Peck IndianReservation 6.3 8.8 .L L * 3 -12.5 17.5 PoplarRiver within Fort Peck Indian Reservation 5 7.5 10 10 1'3.8 " ." "- Soilwater concentration factor of 2.0 is assumed. (Adaptedfrom the Uses and Water QualityObjectives Report)

Thereare also several minority opinions in boththe Board Report and the Usesand Water QualityObjectives Committee Report. One opinion, signed Dr. by D. S. Brown (Montana Department of NaturalResources and Conservation), Dr. J. R. Sims (Montana State University) and Dr. A. Horpestad (a Board member; Montana Department of Health)contained data from theCommittee's Report which leadto theminority opinion that any increaseover the natural levels of boron in theBasin would adverselyimpact the yield of irrigated barley. The authorsstated that: "T'he averageannual concentration - 133 - of boron in theEast Poplar River ... hasremained within therang? of 1.6-1.9 mg/l duringthe period 1975 through 1977, in spite of Cookson Reservoir." In a minorityopinion to the Board Report Horpestadstated that only the crops grown atpresent were considered by the Board. He notedthat increasing boron will limit tnefuture crop possibilities, and thatthe effects of boron and TDS on crop yields is notwell understood. He also notedthat the Eaton experiments(on which theBoard's conclusions are based) were short-term and did notreflect possible lony-term effects of boron on perennial.crops such asalfalfa. He concluded,however, that t he values in the Board'sReport are probably safe for short-term alfalfa becausethe use of Eaton'sdata leads to a built-insafety margin foralfalfa, and because the high predicted boron concentrations wi1.L notoccur for some tens of yearsbecause of delays in seepage of boron-richwaters from the SPC plantash lagoons. Ye alsostates that Eaton's data i.ndicate that any increase in boronabove natural. levels will causedecreases in bar ley yields.

Dr. J. R. Sims, a memberof the Uses and Water Quality Objectives Committee anda co-signer of oneof theminority opinions,presented additional comments concerning the effectsof boron on crops. Citing data in the Board'sTables 3.5 and 3.6, Sims concludedthat even with alfalfathe use of water with 5-6 mg/l of boron will cause yield reductions compared to water with natural levels of boron. He alsoconcluded, using data from the Uses and Water QualityObjectives Committee Report,that irrigation water with 15 mg/l boron would leadto alfalfa yield reductions of 40-50 percentrelative to natural levels of boron. He furtherstated that the concept of croprotati.on was notconsidered by the Committeeor the Board,nor were the effects of boron on wheat,safflower, faba bean,sunflower or dry beans considered.

Dr. D. C. Cameron from AgricultureCanada, a member of the Uses and Water QualityObjectives Committees, reviewed anumber of - 134 -

studies which examinedthe effects of variousboron concentrations on several crops, including wheat, alfalfa and barley. He indicated these data were not always easy to interpret because of different experimental conditions in each study. In some cases, yield reductions occurred at higher concentrations, and i.n other cases at lower concentrations, than those predicted from Eaton's tests. In the case of alfalfa, Cameron noted that the 1929 and 1931 data sets of Eaton gave somewhat different results. He stated that the 1929 data suggested an optimum yield near 10 mg/l boron in soil water, whereas the 1931 data suggested an optimum yield at3-4 mg/l. Cameron cited Eaton's suggestion thatthe d,ifferent results are due to weather conditions and concluded that the 1929 weather conditions more closely resembled the Poplar River situation. On this basis, he concluded that optimum alfalfa yields wouldoccur at soil wat.er concentrations approaching 10 mg/l boron and that yield reductions would occur at soil water concentrations approaching 13-14 mg/l. Cameron concluded that the Board's 6 mg/l boron objective in the East Fork at the International Boundary for irrigation of alfalfa was too conservative, and that a more realistic objectivewould be about 9 mg/l.

Saskatchewan and Montana both have water qual.ity criteria for boron. These criteria are meant to apply province-wide or state-wide, and in most cases natural waters in these jurisdictions do not exceed the criteria. In the case of the Poplar River Basin, however, natural boron concentrations are higher than the Saskatchewan and Montana criteria. The water quality criterion in Saskatchewan is a maximum concentration not to exceed 0.5 mg/l. In Montana, the boron criterion for long-term irrigationis 0.75 mg/l.

The effects of elevated boron levels in irrigation water, as noted above, will be influenced by site-specific factors, including the crop being irrigated, the irrigation practices employed, the boron content of the irrigated soils, the soil type

- 136 - those used in the above experiments, ranging from 7 to 8.5. A review of the scientific literature indicates that in most cases, pH values of 7 to 8 are conducive to boron fixation in the soil and the maintenance of soil water concentrations lower than would otherwise be the case.

After a review of the recent scientific literature, the Commission concluded that Eaton's reports on boron toxicity and on the behavior of boron in soils are valuable sources of information and the Commission has based its conclusions largely on them. A bibliography of some of the more important references on the toxicity of boron and its behavior in the environment is given in Appendix "H" .

After a review 'of the above considerations, the Commission notes that there is no clear indication as to the specific boron levels that will cause cropyield reductions under the conditions that prevail in the Poplar River Basin. Based on the available information, however, the Commission concludes that the irrigation water concentrations for boron contained in Table VI-17 represent the best estimates, available at this time, of the maximum concentrations that should be applied, over the long-term, in order to fully protect the production of the listed crops.

Table VI-17: Maximum Long-Term Boron Concentrations in Irrigation Water for Full Protection of Selected Crops

"" -

I.___Crop "" "Boron-(mg/l) "-."-." alfalfa 5.5 barley 0.5-1.0 wheat 0.5-1.5 "_ oats 2.5.___"""

In arriving at these concentrations the Commission has assumed a leaching fraction of 0.3 and a concentration factor of 2. - 137 -

No site-specific considerations other than precipitation are incorporated in these estimates. The Commission notes that historic baseline boron concentrations in the Poplar River Basin (Figures VI-6 to 13) are frequently at or above these levels €or wheat, barley and oats and, as indicated earlier, has concluded that existing boron concentrations in the Poplar River Basin may already be limiting for some crops. It is not aware, however, of any site-specific evidence that historic or current boron levels in itrigation water have actually caused elevated boron levels in the tissues of irrigated crops, physiological or morphological damage to irrigated plants or reductions in yield.

""Toxicity of TDS in Irrigation Water "" -

The Board found a large disparity in professional opinion and judgement concerning toxicity levels of TDS. It also noted, as with boron, that crop yield reductions due to high TDS levels were highly dependent on such factors as the amount of irrigation water applied, the type of soil, the type of crop grown and the SAR. The Board did provide some general guidelines, which aresummarized in Table VI-18. - 138 -

Table VI-18: Effect of TDS on Crop Production

"_."" ""." - .- -~""." TDS Concentration

" ""_ (mg/l i - Possible .- Effects ."

500 no detrimental effects noted

500-1000 may have detrimental effects on sensitive crops

1000-2000 may have adverse effects on crops, requires careful management

2000-5000 used €or tolerant plants on permeable soils with careful management

The Board concluded that alfalfa, the predominant irrigated crop in the Poplar River Basin, is more sensitive to high TDS concentrations than other crops grown in the region. It also provided some estimates of yield reductions in alfalfa for several TDS concentrations in irrigation water, as summarized in Table VI-19.

Table VI-19: Percentage Yield Reduction of Alfalfa at Three TDS Concentrations for Various Leaching Fractions

." ." """""" ""- Leaching Fractlon - "-*-"-"" TDS (mg/l) . """. 0.1 "._".__ 0.2 0.3 0.4

0% 0% 0% 0% 0% 0%670 0%

1000 3 0 0 0

1350 10 4 1 0 Values are expressedin percentages and do not assume any dilution effect due to rainfall, as would occur under field conditions. (Source: Board Report) As indicateQ~ t:n:'lb:he"Pl::evt~Qe, t~.bcle, the tp~ici ty .effeq-t~' of TDS incr~as~ as the ~eachi~ng fracti.on ~ecreases. At a leac~in~- -. fraction of 0.3, a reduction in alfalfa y~f!;ld is p'f:~icte(1; to occur with a TDS COngentrat:i-o.n'b-.ween 1,000-1,350 mg/l! ~~!.irrigation ------~- - ~- .~.~ __0- . ~ c . water, although the diluting effects of precipitation are again not taken :ifttQ~ aQ:Count. It: ,dilp;t.t:9Q,.pad been taken into account, and all other factors had remained constant, the percentage yield redu.ction:iW():Uld have been l~s.t~ any given le~hin9 fraction.

In correspondence with the Commission, Dr. Rhoades presen~ :~&~i~eQc ~fta.lfa ,Yi~, reductions f~',(geve(.a_l TDS concentrations-as s'UJomarized in Table VI-20.

Table VI-20~ Alfalfa Yield Reductions for Several TDS Concentr;ations.,- . - - -. . . -, ~nd. . Leaching Fracti~on_sr . -

, TPS, r j;~ c , . ,'" - c Concentration ~Leachin9Fra~~ion - (.~.L ~¥~:: ~. 2~~=~ °-. -~ -- J5.Q -- _"~_l'-~". --~,-~",-~y~ - - Q% 1,000 6 0 i.J :0;

1,500 15 6 2 - (SOUrce :' letter from:~Dr. @..oo.~~oades r~;t.IW1,L'September :19, 1979)

'rrbe va:l"ues in "rable VI-20 compare reasonably well with

.. ~- those in Tal11e 'VI: 19!,J although Rhoades1 estimates do indicate siightry~ mo'r~:' tJbt:ent'lcal 'for' damage. As with t-he Board estimates, these values do not take precipitation into account. In addition, Dr. "Rhoad~s ~ffi~~~\~ :ebar"ley a:h~ ',\ofh'e'at-\~titd} tolerate :~! " ' c ;J~:-;?r;C!!~.!,,?J;- :;' ',:1 ~';[:_f)" -;-, approximately three to four times the salinity levels tolerated by alfalf~~ ~- ~~';~:~_?f2].~S~ - ' :'~' .~ --~

Rhoade~) noted that :~uccessful ir¥tgation has been conducted in the USSR witlt' TDS concent~tions exceeding 4,000-6,000 mg/J...' There are instan.ces of "usable" water in India with TDS values 1 .ranging up~t6~lT;U(fOm9/l. 'He~stressed, howev~r;~that: the use of - 14 0 "' suchelevated rrm irric~a.i:.ionwaters required careful management. practices, and that these practices were generally m.ore stringent thanthose normally us~?din irrigation in thePoplar River Basin. He also stressedthat the salinity 1,eveJ.s which arejudged acceptable in some regions or cc:~untriesmay not apply to the Poplar Riversystem with i.t;s own set of phys hcal,ecc~nomic and climatic conditions. Based on h.%sanalysis of availabl..edata, he expressed confidencethat I' e .water of 1,000 ppm can be used succcessfullyfor irrigation of al.falfa and grain c;rcpgs in t:he PoplarRiver area."

The Uses and, Water Quality Objecti,ves Committee indicated thatirrigakion was zurr,ently being practiced in areas in Montana with watercwntaini ng r[",!~~, cnncentrations above its recommended long-term obj ezt ive of 2. OQCI mg/l and t:he short--terrn (anythree consecutive months) ob:jective of 1,500 rng/l. The Committee also noted,however, that there were areas in northern Montana where irrigation opera,t.ions u'ki.l..i"Zing waters with TDS concentrations I.ess than its recommended objectives have Ea iled.

As with ~OTCSII,there were ~ninorityopinions in the Board Report and in the Uses and Water Qualityab-jeztives committee Report concerning the effects of TDS crn crops. Dr A. Horpestad, a member of both.the Board and the Conr:ni,ttee, statedthat the data used to predictthe effects c:)E increasing rrDS concentrations on crop yields were not good because the ohsecved effects of large lrns increases wereused to predict the effects ~:)f small 'I'DS increases.

Dr. J. R. Sirns I a member of the Uses and Qbj ectives Committee, also presentedadditional views concerning acceptable TDS levels. He indicatedthat in the summary of references on irrigationwater yuali.ty contained in the Uses and Water Quality Objectives Committee Report, * in a1.l cases,except for the Saskatchewan criteria which is not referenced,that irrigation waters with over SO0 to 700 :fig//:! TDS wouXd !-rave detrimentaleffects - 141 -

on crops...'' He also stated that when TDS levels increased to above critical levels, additional management practices mustbe used or a decreased crop yield would occur. He also described salinity toxicity experiments that he had conducted using six plant species. Although noting that the experiments were incomplete,he concluded that all six crop species showed large declinesin dry matter production with TDS levels above 750 mg/l, and hence concluded that the Board's recommended long-termand short-term TDS objectives of 1,000 mg/l and 1,500 mg/l, respectively, may be too high.

The Montana TDS criterion for long-term irrigation is 500 mg/l. It is noted that Saskatchewan has not established a specific water quality criterion for TDS.

The Commission.notedthat effects on crop yieldsare not the only effects of elevated boronor TDS concentrations in irrigation waters. Farm management practices may haye to be changed to help counteract increasesin boron and TDS if these levels exceed those that are critical. Changes in farm management practices could include reducing the choiceof crops; increasing irrigation water requirements to meet increased leaching and draining needs which in turn can lead to increased drainage, erosionand runoff problems; increasing use of fertilizers; better land preparation; increasing seeding rates to compensate for reduced germinationand increasing labour requirements. Although the Board emphasized many of these considerations, it did not have the necessary site-specific information to consider them in a quantitative manner.

After a review of the above considerations, the Commission concludes that the irrigation water TDS concentrations contained in Table VI-21 represent its best estimates, at the present time, of the maximum concentrationsthat should be applied over the long-term in order to fully protect the productionof the listed crops. - 142 -

Table VI-21: Maximum Long-Term TDS Concentration in Irrigation Water for Full Protection of Selected Crops

- -Crop - %L.!m!LLL" - alfalfa 1000-1300 bar ley 4000 wheat 4000

In arriving at these concentrations the Commission has assumed a leaching fraction of 0.3 and a concentration factor of 2. No site-specific considerations other than precipitation are incorporated in these estimates. The Commission notes that alfalfa is considerably more sensitive to elevated TDS levels than either barley or wheat, although it does not appear that existing TDS concentrations in the Poplar River Basin are high enough to limit alfalfa production. Unfortunately, however, site-specific data that would help one assess whether or not crop yields are actually being reduced because of TDS concentrations are not available.

IMPACTS OF WATER _."USES, APPORTIONMENTAND THE "-PROJECTSPC ON THE POPLAR RIVER SYSTEM

The Commission presentedbaseline water quality conditions in the Poplar River Basin, as well as its best estimates of critical boron and TDS concentrations for the long-term irrigation of selected crops in the Basin, in earlier sections of this chapter. This section consists of an assessment of projected changes in boron and TDS concentrations resulting from different levels of water use in the Basin, including projected water uses in Montana, changed flows that will result from the specific provisions of the recommended apportionment, and the SPC project. The computed historic baseline values for boron and TDS, or other appropriate baseline reference values, are compared with the concentrations projected to occur as a result of the above activities. The - 143 - differences between thebaseline values and theprojected values resulting from a givenactivity provide a measure of thepotential impact of the specificactivity on waterquality in thePoplar River System.

Severalconsiderations should again be noted in examining the assessments in this section. The estimates of theimpacts of thevarious activities noted above, as well as the estimates of baselinewater quality, were derived with theuse of mathematical models. The generalconcerns raised earlier in this chapterabout the use of such models arealso valid here. The limitedquantity of baselinewater quality data for the Poplar River System is also a matter of concernto the Commission. It is recalledthat historic baselinewater quality is that assumed toexist in 1975, with a 1975 level of wateruse in the'united States and Canada.Neither Cookson Reservoir nor the SPC plant wereassumed to exist. As noted in the section on baselinewater quality, although there was a tendencyfor the models tooverestimate mean springlevels and tounderestimate meansummer levels ofboron and TDS atthe upper stations in the Montana portion of the PoplarRiver Basin, the Commission neverthelessconcluded that the model-generatedprojections of water quality were sufficientlyaccurate to be used forthese comparisons. The Commission alsonotes, however, thatall model projectionsrepresent long-term "average" conditions which should be viewed as approximationsrather than absolute values. There is a range of uncertaintyaround all the projections which is difficult to quantify. As a result, the boron and TDS concentrations in a givenyear could be betteror worsethan the projected average values. -- 144 -

IMPACTS OF COOKSON RESERVOIR ON WATER QUALITY-

Cookson Reservoir is a new dominant component in the Poplar River hydrologic regime. Inflows of water from the East Fork and other smaller upstream tributaries, as well as occasional overflows from Fife Lake, and the constituents carried by the water (such as boron and TDS), are stored in Cookson Reservoir and will mix with inputs from direct precipitation,groundwater and the SPC plant and its ancillary facilities. Water losses from the reservoir, both controlled and uncontrolled, will occur as a result of controlled releases to meet the specific East Fork flow requirements of the recommended apportionment, spillage over the spillway, seepage through, under or around Morrison Dam, natural evaporation, and forced evaporation resulting from the use of the reservoir water for cooling purposes.

Because of the large volume of Cookson Reservoir relative to its inflows and outflows, the waters in the reservoir, or released from the reservoir as a function of the apportionment or from seepage through, under or around Morrison Dam, will be a composite or "average" of the various inputs that entered the reservoir during the previous months and years. The full storage ca.pacity of Cookson Reservoir is estimated to be 41,166,000 m 3 (33,373 acre-feet). This is approximately threetimes the volume of the mean annual measured flows into the reservoir and is four to five times the mean annual flows that are expected in the East Fork at the International. Z3oundary as a result of the recommended apportionment and the operation of the SPC plant and its ancillary facilities. Because of these factors, the dramatic month-to-month and year-to-year variations in quantity and quality that have characterized the East Fork in the past will be greatly reduced.

The measured boron and TDS concentrations in Cookson Reservoir and on the East Fork at the International Boundary (Figure - 145 -

VI-15) illustrate this leveling effect of the reservoir on both the quality and quantity of the transboundary water flows. The concentrations in Figure VI-15 are instantaneous measurements, while the flows are measured monthly mean values. The monthly mean flows in both the East and Middle Forks at the International Boundary are illustrated. Since the flows at these two locations have generally Seen similar for the 1931-1974 period of flow record, the differences in flows in the post-reservoir period since 1975 provides an approximation of the effect of the reservoir on flows in the East Fork at the Boundary since that year.

There was a considerable variation in boron and TDS concentrations in the East Fork on a month-to-month basis as the reservoir was being completed, with the boron and TDS concentrations being lowest when the flows were highest. Variations in the concentrations of boron and TDS decreased dramatically once the reservoir began to store water early in 1976. On the East Fork at the Boundary, the boron and TDS concentrations generally remained in the 1.6-2.0 mg/l and 800-1.100 mg/l range, respectively, throughout most of 1977 and 1978. Transboundary flows in the East Fork were low in 1977 and 1978. The flows and concentrations in the East Fork at the International Boundary during this period were due primarily to groundwater containing relatively high boron and TDS concentrations. Following storage of a comparatively high 1978 spring inflow, the boron and TDS concentrations in Cookson Reservoir were in the range of 1.1-1.4 mg/l and 600-800 my/l, respectively, considerably lower than those in the transboundary flows. In the spring of 1979, another influx of relatively high quality water further reduced the reservoir concentrations of boron and TDS to about 0.8-0.9 mg/l and 400-SO0 mg/l, respectively. From March through June, the flow at the Boundary apparently consisted mostly of reservoir outflow. Consequently, reservoir and Boundary boron and TDS concentrations were similar. The overflows from the reservoir ceased during the period from June-September 1979 and the - 146 -

I975 1976 1977

Figure VI-15Neasured Boron and TDS Concentrations (Cookson Reservoir and East Fork at Boundary) and ivlonthly Mean Flows (East and MiddleForks at Boundary) Between 1975 and 1980 - 147 -

1 - East Fork at International Boundary 1

- - -* -e .- Cookson Reservoir

NOTE: TDS concentrationsin Cookson

IO0 East Fork at International Boundary 80 , -.-. lliddle Fork at International i3ouldhxy I 60

40

20

0 I978 1979 I980

Figure VI-15 Measi-:I..=j. Boron ana TDS Concentrations (Cookson Reservoir (cont'd) 211i East Fork at Boundary) and Monthly Mean Flows (East GT,~Middle Forks at Boundary) Betwtkii 1975 and 1980 flows at the Boundarywere againprimarily due to groundwater.

There was also some seepagethrough, under and aroundMorrison Dam.

The indicationsare that the combined seepage and groundwaterflows are now considerablyhigher than the base flow that occurred prior to completion of thereservoir or during the reservoir filling period. The boron and TDS concentrationsat the Boundary consequentlyincreased again to essentially groundwater levels. The concentrations in thereservoir, however,remained at approximately the March throughJune levels, illustrating the role of the reservoiras a hydrologic componentwhich will "average"out the impacts of high and low. flowsover time.

". ". PredictedImpacts of Water Uses in the-United States -"

The projectedimpacts of variouslevels ofdevelopment in the Montana portion of thePoplar River Basin on boron and TDS concentrations in theBasin are presented in this section. An evaluation of theseimpacts is intendedto assist the Commission in assessing the netimpact of uses in Canada on downstreamwater quality.Predicted future uses in theSaskatchewan portion of the

Basinare related primarily to the SPC power project and are thereforenot included in this section.Attention was focussed on stations in Montana below theInternational Boundary sincethese - 1.49 - stationsrepresent the areas where thefuture uses are predicted to occur, and thereforethese are the stations where waterquality is most likelyto be influenced by futureuses of water. The specific stations used in this assessment were theEast Forkabove Scobey (Station 3), thePoplar River belowScobey (Station 8), the West Fork nearBredette (Station 11) and thePoplar River near Poplar (Station 12). The scenarios examined reflectedprojected water uses forthe years 1975, 1985 and 2000 in the U.S., and usesfor the year 1975 in Canada. The scenarios assumed that no reservoiror SPC power plant were in existence an theEast Fork and that no apportionment was in effect.

In examiningthe projected impacts of wateruses, the Commission notedthat the data were relativelysparse for a11 stationsexcept the East Fork nearScobey. This was due primarily tothe fact that the modelsused forthe projections are programmed such thatthey do notpredict boron and TDS concentrations when flowsare less than 0.0142 m3 (0.5 cfs) . Flowsbelow this level, however,occurred €or a majority of yearsat the stations examined, particularly from late summer throughthe winter. Hence, with projectedwater uses for the years 1985 and 2000, thewater quality projectionsduring September and October at a station may, for example,include less than 10 years in which flows atthe station exceeded 0.0142 m’ (0.5 cfs) , whilefor these same months projectionsfor the 1975 level ofuses often include data for 35 to 42 years of theperiod of flowrecord. Thus, a directcomparison of mean or median valuesbased on suchdifferent sample sizes can be misleadingbecause the conditions in the low flowyears, when one would expectpoor water quality, would not be reflected in the 1985 and 2000 projections.

The Boardtook thediffering sample sizesinto account and concludedthat boron and TDS concentrations in the West Forkwere not affected by the 1975 uses, relative to pre-development uses. - 153 -

The Board also concluded that 1975 uses had a "substantial impact" on boron and TDS concentrations in the Middle Fork above its confluence with the East Fork and that the 1975 uses only "slightly affected" boron concentrations in the East Fork and in the Poplar River near Poplar. It also concluded that 1975 uses had little impact on the TDS concentrations in the East Fork, although these uses "caused higher TDS concentrations" in the Poplar River near Poplar, Yontana.

The Commission agrees with these conclusions. In addition, the Commission believes that the projected 1985 and 2000 uses in the United States are unlikely to have much impact on boron and TDS concentrations in the East Fork since only limited uses have been identified for this area. Because of the constraint on the model pcojections noted above, the impact of increased levels of use in the United States on the water quality at other stations in the Poplar River Basin is not clear. The projected 1985 and 2000 level of water use in the United States will reduce the amount of flow in the Poplar River System, especially at the downstream stations, and would likely result in degraded water quality associated with the reduced flows.

Predicted Impacts of Water Apportionment

Impacts on Water Quality

The Commission was asked to consider the effects on water quality and on water uses of "changes in the flow regi.me of the Poplar River if apportionment of the waters of the Poplar River is made as recommended by the International Souris-Red Rivers Engineering Board's Poplar River Task Force in its Report of February 6, 1976, or as the Commission may otherwise recommend." In assessing the effects of these changes, the Commission has included the impacts of Cookson Reservoir operated in accordance with the recommended apportionment. - 151 -

The projected impact of the recommended apportionment on boron and TDS concentrations in the Poplar River Basin is discussed in this section. The effects of apportionment are examined by comparing a scenario which assumes no reservoir and no apportionment, with a scenario which assumes Cookson Reservoir and the apportionment in effect. Such a comparison is presented in Tables VI-22 toVI-27 for several stations in the Poplar River System. The 1975 level of water use in the Basin is assumed. The Commission used results from two scenarios in assessing the impacts of apportionment. Because several factors were not consistent between the two scenarios, it was not feasible for the Commission to compute the effects of the apportionment Zlows at the two stations below the confluence of the East and Middle Forks. As previously discussed, the model projections for the period October-February are not included in Tables VI-22 toVI-27 because the models do not predict boron and TDS concentrations when flows are below 0.0142 3 m /s (0.5 cfs), which oEten occurs during this period.

The most significant projected impacts of CooksonReservoir operated in accordance with the apportionment on boron and TDS concentrations are in the East Fork at the International Boundary during the period from March to June (Table VI-22) . The projected values for the non-apportionment scenario range from 0.5-1.1 mg,/l, while the projected values under the reservoir and apportionment scenario are relatively constant at 1.6 mg/l during this period. The corresponding projected TDS values €or the non-apportionment and apportionment scenarios are 360-620 mg/l and 750-830 mg/l, respectively. The projected values for the two scenarios are generally similar by late summer. These differences between the non-apportionment and apportionment scenarios are less pronounced as one moves downstream on the East Fork (Table VI-23). It is also noted that the projected boron and TDS concentrations under the reservoir and apportionment scenario, while higher during the spring period than the non-apportionment values, do not exhibit the dramatic - 152 -

TableVI-22 Predicted Effect of Apportionmenton Mean Boron "" and TDS Concentrations:

East Fork at InternationalBoundary - ___""BORON (mg/l) March April May- June """___July Aug. Sept. no apportionment no 0.5 0.8 1.0 1.11.6 1.3 1.4 (noreservoir) (no plant) apportionment 1.6 1.4 1.6 1.61.5 1.5 1.6 (no reservoir) (noplant)

no appor t ionmen t 360 470 820550 720 620 770 (no reservoir) (noplant) apportionment 830 750 810 820 810 820 860 (no reservoir) (noplant)

-~.~-Table VI-23Predicted Effect of Apportionmenton Mean Boronand TDS Concentrations:

East Fork AboveScobey

" - BORON (m

no apportionment510 no 540 650 830710 860 780 (noreservoir) (noplant) apportionment 880690 840 720 850 830 910 (noreservoir) (no plant) - - 153 -

_"____Table VI-24 PredictedEffect of Apportionmenton MeanBoron and TDS Concentrations:

MiddleFork at InternationalBoundary

"""" BORON ) (mg/ 1 March April -~""I_June July Aug. Sept. """I_ May ""_."" no appor t ionmen t 0.8 0.7 0.8 0.9 1.0 1.0 L.0 (noreservoir) (noplant) apportionment 0.9 0.9 n.9 0.9 0.9 0.9 0.9 (30 reservoir) (nopLant) __ "_" __- TDS (mg/l) """ -I_ no appor t ionmen t 590 540 590 630 670 7 .LO 720 (noreservoir) (no plant) apportionment 690 670 660 670 670 670 690 (:IO reservoir) (noplant)

Ta!->le VI-25 Predicted EEfect of Apportionmenton Mean Boron and TDS Concentrations:

?liddie FQrk Above ConfLdenccNith East For!:

BOROFJ (mg/l) March__"" L""Aoril Nay June J1~l.y- Aug. Sept. no apportionment no 0.8 0.7 0.9 1.0 0.9 1.0 1.2 (noreservoir) (no plant)

"_ ."""~-"."_"""-__.I_ " " appor ti onment 0.8 0.8 1.0 1.1 0.9 1.1 1.1 (no reservoir) (noplant)

no apportionment no 550 530 640 700 630 730 820 (noreservoir) (no plant) apportionment 610 590 680 750 660 750 780 (noreservoir! (no plant)

"_.____ ." ." -" " .- - "- - 154 -

TableVI-26 Predicted Effect of Apportionmenton MeanBoron and TDS Concentrations:

West Fork at InternationalBoundary

"" " BORON"""""-."__I__""" (mg/ 1 ) MarchApril May JuneJuly Aug. Sept. noapportionment 1.0 0.7 0.8 0.7 0.8 0.8 0.8 (no reservoir) (no plant)

apportionment 0.9 0.9 0.9 0.8 0.9 0.9 0.8 (no reservoir) ( no pl an t)

n o apportionment no 730 490 640 600 680 670 670 (noreservoir) (no plant) apportionment 760 690 680 680740 740 670 (no reservoir) (noplant)

__ "- - ""

Table" -- - - - Vi-27 - "_ Predicted Effect of Apportionment on Mean Boron and TDS Concentrations:

West Fork NearBredotte

~~ BORON (mg/l) March April May JulyJune Aug. Sept. "" - ~ noapportionment 0.2 0.2 0.4 0.5 0.6 0.7 0.6 (no reservoir) (no plant) apportionment 0.2 0.2 0.4 0.5 0.6 0.7 0.6 (noreservoir) (no plant)

no apportionment 440 430 610 660780 730 800 (no reservoir) (no plant) apportionment440 440 610 660790 730 800 (no reservoir) (noplant)

~- .I ." - 155 -

month-to-month variations characteristic of pre-reservoir conditions. This is primarily a result of Cookson Reservoir storing the high quality spring flows which previously had passed downstream. The Commission concludes that a major effect on the East Fork at the Boundary of Cookson Reservoir operated in accordance with the recommended apportionment will be to substantially redJce the month- to-month variations in water qual-ity that existed prior to the construction of the reservoir. Specifically, eEfects will include an increase in the mean concentrations of boron and TDS during the spring months and a maintenance of higher mean flows and generally higher mean concentrations of boron and TDS during the summer and early autumn. Measured values for the 1975-1980 period (Figures VI-6 to VI-13) are generally similar to the model projections for the reservoir and apportionment scenarios.

The predicted impacts of apportionment were not as pronounced at the other stations examined by the commission, and differences between the non-apportionment and apportionment scenarios were relatively insigniEicant. The Commission again notes, however, that some of the predicted mean values were computed from a small. number of samples because of projected flows below O.OL42 m3/s (0.5 cfsj. For example, this is the case at several stations for the late summer-early fall period for both the apportionment and non-apportionment scenarios. Elence some caution is needed when comparing the predicted water qual-ity values for the apportionment and non-apportionment scenarios.

As noted above, the Commission was unable to make quantitative predictions of the effects oE apportionment on boron and TDS levels at the two Poplar River stations below the confluence of the East and Middle Forks. The Commission notes, however, the decreased effect of apportionment, relative to the non-apportionment scenario, on boron and TDS concentratiQns in the East Fork as one moves downstream from the Boundary to Scobey. The insignificant - 156 - differences in theapportionment and non-apportionmentvalues atthe otherstations are also noted. Based on theseobservations, the Commission concludesthat the effects of apportionment will be minor at the two stations below theconfluence of theEast and Middle Fclr k s .

Impacts on BioLogicalResources "_ "" ""

No adverseimpacts on thebiological communi.ty in the PoplarRiver Basin are ex2ected to result fromchanges in water quality. However, some adverseimpacts in theEast Fork are anticipated due tochanges in theflow regime under the recommended apportionment.

The Board concludedthat "the proposed water quantity apportionment of the PoplarRiver System is expectedto adversely affectthe biological. resources of theEast Poplar River by reducing the natural effects of high spring flows which reach 20 m 3 /s (700 cfs) on theaverage every two years." The BiologicalResources Committee estimatedthe major impactsas: up to a 50 percent increase in thegrowth of rootedaquatic plants in theEast Fork; up kc^ 25 percentdecrease in thequantity of streamflowdependent algae in theEast Fork; up to a 75 percentdecrease in thewalleye population in the Lower East Fork; and up to a 50 percentreduction inannual duck production in theEast Forkdue tohabitat alteration,resulting primariLy from theencroachment of thestream bed by rootedaquatic plants. The committeeestimated that this encroachment of rootedaquatic plants "could result in the eventual loss of approximately 70 to 80 breedingp.airs of ducks, and the production of between 300 and 400 ducksannually." The Committee concludedthat "the upper reaches of theEast Poplar provided better duck habitatthan other portions studied. Emergent vegetation was more abundantalong the upper 14.5 km (9 mi) of theEast Poplar and particularlythe upper 6.4 km (4 mi) compared tothe rest of the PoplarRiver. - 157 -

The actual impacts on the biological community in the Poplar River Basin cannot he fully assessed at this time. The Committee and the Board proposed similar, though somewhat different, discharges as being necessary to maintain the existing aquatic habitat of the East Fork. While the duration and frequency of these high flows cannot be met if the SPC project operates as expected, the Commission notes that these flows did not occur under natural conditions This matter is discussed in a report submitted at the final hearings of the Comnission by the Canadian Co-chairman of the Plant, Mine and Reservoir Operations Committee. The report is part of the official record of this Reference and is available for public inspec tion.

The Commission notes that in many years it is likely that the available water will exceed that required by the SPC project. Consequently, there will be times, particularly in the spring, when discharges from Cookson Reservoir will exceed those called for in the proposed apportionment. This suggests that with operation of the two-unit SPC plant and no other water uses occurring in the Canadian portion of the Basin, there will be water available in the East Fork which could reduce, at least to some degree, the adverse effects on the biological resources in the East Fork discussed earlier in this section. The timing and future availability of this water, which is part of Canada's share under the recommended apportionment, could be the subject of discussions and possible agreement between the appropriate Governments in each country.

In addition to the above, the Commission notes that the Biological Resources Committee recommended the following measures for offsetting losses in biological resources in the East Fork and for taking advantage of wildlife habitat potential in northeastern Montana and Canada: (1) the use of land at Outlet Creek Marsh, 4 miles east of the East Fork on the Boundary, to provide additional habitat for waterfowl; (2) the management of selected lands along the East Fork for wildlife; (3) the utilization of Carrol Dam, 4 - 158 - miles northwest of Plentywood in northwestern Montana, for the enhancement of fish production and water related recreation; and (4) the implementation of a waterfowl development plan on and around Cookson Reservoir.

Many of the above factors were not identified and therefore not considered by the Commission in its 1978 Report on Apportionment in the Poplar River Basin. The Commission believes that all such matters s'nol~ldbe considered by Governments in reviewing the apportionment recommended by the Commission. This matter is discussed briefly in Chapter VI1 of this report.

Predicted Impacts of Cookson Reservoir and the SPC Power Project """."_I_ "" "_

Impact on Water"Quality-

Since the SPC plant is located on the East E'ork, the water quality impacts of the SPC plant will occur only in the East Fork and in those portions of the Poplar River System into which the East Fork flows. The water quality below the confluence of the East and Middle Forks will, of course, be a function of the quality and quantity of the water from both Forks, while the water quality at Poplar, Montana will also be influenced by the water quality and quantity in the West Fork.

The model used to assess impacts of the SPC plant was similar to the mass balance model used to predict historic baselilne water quality. A reservoir model was used to predict in-reservoir concentrations of boron and TDS as a function of the operation of the plant and its ancillary facilities. These in-reservoir concentrations, as well as estimates of seepage from the reservoir and ash lagoon system, were then used as input values €or the model used by the Surface Water Quality Committee to predict the resultant water quality throughout the Poplar River System. - 159 -

This Committee, 3s wellas the Plant, Mineand Reservoir OperationsCommittee, examined theeffects of anumber of different scenariosfor the SPC plant. As noted earlier, however, subsequent to the Board'sReport, the original once-through ash lagoonsystem design was altered by SPC toincorporate a closedrecirculating ash lagoonsystem. As a result of this redesign, most of the predictions of the SPC projectimpacts presented by the Board and its Committees are no longerapplicable under present circumstances. At theCommission's final public hearings on thi.5 Reference,the Plant, Mine and ReservoirOperations Committee and theGroundwater Quankity and Quality Committee submitted a SupplementaryReport on behalf {of the Boardwhich containedrevised projections of boron and TDS concentrationsfor the East Fork at the International Boundary,based on therevised ash lagoon system and the most recentestimates of ashlagoon seepage rates. Furthermore, the Cornmission has receivedadditional computer projections of boron and TDS concentrations,throuyhoilt the Poplar RiverSystern, based on theserevized estimates. The resuLts of theseadditional computer runsare presented in Appendix I. The Commission notesthat for the East Fork atthe International T3oundary, theonly station common to boththe Supplementary Report and theadditional computer projectionscited above, the predicted boron and TDS valuesare similar.Differences that do occurare ninor and areapparently due to some differing model assumptions.

The majorcomponents considered in thereservoir models of boththe Plant, Mineand ReservoirOperations Committee and the Surface Water Quality Cominittee are summarized in Figure VI-16. All of these componentscan influencethe predicted boron and TDS concentrations in thePoplar River Systen, particularly on theEast Fork. As notedearlier, the inputs of waterto the reservoir are stored and mixed in thereservoir. As a consequence of consumptive losses in thereservoir (primarily evaporation), the volume of reservoiroutflow is typicallyabout 40 percentless than the - 16'3 - - 161 - combined inflows.Since constituents such as boron and TDS are assumed to behave conservatively,the net effect of theevaporation losses is toincrease the average outflow concentrations of these constituents. The naturalinflow to the reservoir and the evaporation from thereservoir have a dominant influence on the concentrations at theBoundary, principallybecause of theirlarge volume relativeto other inputs and outflows.Seepage from theash lagoonsto the reservoir or the East Fork is alsoimportant because of thepredicted high boronconcentr.2tions in the asn lagoons.

Thereare two assumptions in thereservoir model which govern the overall manner in which theindividual parameters are incorporated and treated in thereservoir model.These assumptions are as follows:

1. Boron and TDS wilL behave conservatively in theirpassage throughthe Poplar River System. This means thatthe boron and TDS, generated as a result of the SPC plantor its ancillaryfacilities, together with thenatural inputs, will eventual.1.y movedown theEast Fork and acrossthe International Boundary. It is assumed that none of the boron or TDS will be retainedalong groundwater pathways or within thereservoir or the river. At least some of the boron,however, will. undoubtedly be retained within the soiL. This assumption,therefore, at least in thecase of boron is conservative, and may even be veryconservative depending onhow much boron is actuallyretained in the soil. Yore site-specific study wili be requiredto quantifythe extent (e.g., LO, 50 or 90 percent) of this boron attenuationcapacity. Some discussion of the boron attenuationcapacity of the soils in theEast Fork is contained in thereport of thePlant, Mine and Reservoir OperationsCommittee. - 162 -

2. Steady-stateor equilibrium conditions are assumed to exist in thePoplar River System. This means that in predicting impacts,the model assumes thatthe SPC project is in full operation and that theinputs of water,boron and TDS from allsources will exerttheir effects on thesystem simultaneously. The Board indicated, however, thatthe seepagefrom the ash lagoon system may notreach the East Fork for 50 yearsor more because of slowgroundwater movement. This period of tine is longerthan the projected life of the SPC plant. Even if theseepage should reach theEast Fork duringthe proposed life of theplant, the incr2ases in boron concentrationspredicted to occur as a result of theplant operation (such as forced evaporation in thereservoir) and theash lagoon seepage would not b +.I1 simultaneouslyaffect ~~ater qualityin theEast Fork throughoutthe entire projected life of theplant, as was assumed in thereservoir model-. There would atleast bo some lagperiod before the ash lagoon seepagereached the East Forkand/or Cookson Reservoir.Because of the relativelylong residence time of water in thereservoir (onthe order of 3-5 years), it may takeyears or even decadesbefore the water quality of the inputs tothe reservoirreaches an approximateequilibrium with the water- quality of theoutflows from thereservoir.

Theseassumptions insure that an element of conservatism j.5 incorporated in thetreatment of theindividual reservoir model components, particularly in thecase of boron. Theydo not, however, insurethat the actual values af any of thereservoir moue1 components(Figure VI-16) will not be eitheroverestimated or underestimated. Most of thespecific values assigned to .the individualparameters are "best estimates" based ona variety of empirical. and quantitativeevidence plus thesubjective judgment of experts. Some of thevalues for parameters in thereservoir model, - 163 - aswell as the surface water quality model parameters,can be estirnatedor predicted with reasonableprecision. For other parameters,however, there is a greaterdegree of uncertainty. This means that it is likelythat some values of the model garametersare overestimatedwhile others are underestimated. The reliability of the model predictions wi.11 depend on theparticular mix of the reasonableestirnat.es, and theoverestimated or underestimated value:;. If some or most of theestimated values for the more importantparameters havebeen toooptimistic, it is entirely possiblethat the cumJlative effect of theseoptimistic assumptions wouldmore thannegate the effect of theconservatism inherent i.n the above two assumptions.Consequently, future watc.r quality c0ul.d beworse than the predicted values, despite the conservative nature o€ themodel. On theother hand, if theestimates for individual parametersare too pessinistic, future water quality will probably be betterthan that predicted by themodels. More site-specific information would serveto narrow the range of uncertainty of the values €or most of the more important model parameters.

The Comrnission notesthat a veryimportant component of the model about which there is uncertainty is theestimates of seepage rates from theash lagoon system. The seepagerates and the concentration of theboron in theseepage are important parameters of thereservoir model. The predictedimpacts of variousseepage rates from therecirculating ash Lagoon system on boron and TDS concentrations in theEast Fork ,at theInternational Boundary are presented in Table VI-28. The values in this Table are taken from thecomputer runs presented in Appendix I. The modelassumed a boron concentration of 50 mg/l in the ash lagoonseepage, although indications from severalsources suggest that lower concentrations may actuallyoccur under field conditions. The seepagerates in Table VI-28 representthe maximum, minimum and bestestimates of the PLant, Mineand ReservoirOperations Committee and the Groundwater Quantity and Quality Committee forthe ash lagoon system. The three - 164 - scenarios assume a two-unit SPC plarlt in operation and the recommended apportionment in effect,as well as the 1975 level of ~ateruse in theBasin. Themean predicted boron concentration in theEast Fork at the Boundary increases as thetotal :seepage rate increases, for the per iod examined. The impact OE increased seepage rater, 33 medn TDS Icvels at the Boundary is relatively insignificant. ‘rh? seepage rates Erom the ash lagoonsystem can be ,~sr,:~ssedmore accuratelyafter the ash lagoons are in operation. This will be one CI~ the components of theCooperative Monitoring Progrlm for the Poplar RiverBasin, which is described in Chapter VII. The Commission nQtes that one of theconditions of the liqpnsi? permitting the Saskatchewan Dower Corporati:3n toconstruct the ash .i,lgoon systen is that the total seepage rate not exceed 2 lis. - 165 -

Table- "" VI-28 Predicted Effect of Various Ash Lagoon Seepage Rates on Mean Boron and TDS Concentrations in the East Fork at theInternational Boundary

- BORON (mg/l) March April May June July Au3. Sept.." to river - 0.5 1/s 2.l. L.8 1.9 2.0 2.0 2.7. 2.2 to reservoir - 0.1 l/s (minimum estimated seepage rates)

to river - 1. .O 1,'s 2.4 1.9 2.1 2.1 2.1 2.2 2.4 t!> reservoir - 0.1 1/s ("5e;t estimate") to river - 2.0 l/s 2.9 2.2 2.5 2.5 2.5 2.7 2.9 t:o re:;:?rvoir - 1.0 Lis (naxirnum estimated) seepage rates)

to river - 0.5 1/s 1000 910 950 980 1000 10601040 to reservoir - 0.1 1,'s (minimum estimated) seepage rates) t:-o river - 1 .O l/s 10 LO 910 960 990 1010 1050 1.070 to roscrv0i.r - 0. .L 1-/s ("best estimate")

to river - 2.0 1/s 1030 930 , 970 1000 1020 1070 1090 t.o reservoir - 1.0 l/s (maximum estimated) seepage rates) - 166 -

The reservoir model predictions of the SPC plantimpacts cannot yet be verified with fielddata because the SPC project is n3t yet in €1-111operation and it will probablybe years before the full watercquaiity impacts of all components of the SPC project will be reflected in boron and TDS levels in theEast Fork at the International.3oundary and at downstream ststions.Yotwithstanding this consideraticn,the Com-nissionconcluded thatthe mass balance approachused by t!leRoard and its Committees is basical'ly sound and tht thevarious parameters and valuesused as inputsto the models were reasonableestimates for the scenarios considered.

The projectedimpacts of thetwo-unit SPC plant on boron and TDS concentrationsare presented in Figures VI-17 to VI-20. since the potential.impacts of the SPC project on surfacewater qualityare anticipated only in the portion of thePoplar River which receive:;inputs from theEast Fork, attention is focused 011 .;tations i.q thesesections of the ~opl.arRiver System. The historic baselinevalues (no reservoir, no apportionmeqt, nopower plant) and the st.at:ls quo val~le:;(reservoir, apportionment, nopower plant)are also presented. This comparisonprovides an assessment of the SPC project on PoplarRiver Water Quality,relative to the conditions which existedprior to construction of the Cookson Reservoir. Tile

1975 level of water 1usc3 in the Basil? was assumed in aI'L cases. Ash lagoonseepage rates of 1 L/s to Cookson Reservoir, and 0.1 1/s to theEast Forkbetween the reservoir and above theInternational Boundary, were ,also ,3ssumed. T5eseseepage rates werejudged as "bestestinates" in the SupplementaryReport, and the Commission chose 00 usethese estimates in Figures VI-17 to VI-20. The Commission notes, however , thatthe predicted boron and TDS concentrations would be higher ar lower if the maximum or mi.nimum values,respectively, of thepredicted range of seepagerates in the SupplementaryReport had beenused in the model projections. Mean boron and TDS concentrations were predicted for each month of the 42-yearperiod of flow record. The mean concentration is thus the - 167 -

'11'1'I i I i I ~ -.. 1 Reseryoir With S PC Plant

JANSEP AUGFEB JUL JUNMAR MAY APR OCT NOV DEC

I800 -1

Figure VI- 17 PREDICTEDEFFECT OF SPC PLANT AND COOKSON RESERVOIR ON MEANBORON AND TDS CONCENTRATIONS INTHE EAST FORK ATTHE INTERNATIONAL BOUNDARY - 168 -

T I "-l-"-7"-l 1

200c

l8OC

1600

I400 h % \ 1200 CT E v 1000 nv, 800 I- 600

400

200

0 Figure VI-I8 PREDICTEDEFFECT OF SPCPLANT ANDCOOKSON RESERVOIR ON MEANBORON AND TDS CONCENTRATIONSIN THE EASTFORK NEAR SCOBEY - 169 -

" I I T

I I I i

JAN FEB APR MAR MAY JUN JUL AUG SEP OCT NOV DEC

Figure vI-19 PREDICTEDEFFECT OF SPCPLANT AND COOKSON RESERVOIR ON MEAN BORONAND TDS CONCENTRATIONS IN THE POPLARRIVER BELOW SCOBEY - 170 -

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV

1600 I I Reservoir With PC Plant I S I I400 c

I 600 ~

400:

200 1

0 Figure VI - 20 PREDICTED EFFECT OF SPC PLANT AND COOKSON RESERVOIR ON MEANBORON AND TDS CONCENTRATIONSIN THE POPLARRIVER NEAR POPLAR - 171 -

nean of all thepredicted monthly mean concentrations for the period of flow record. Theupper and lower valuesfor each data pint are the90th and 10th percentile values. Hence, the il1.lIstratedranges in Figures VI-17 to VI-20 encompass 80 percent ofthe monthly mean values predicted from the recorded flows. The Commissionhas concluded, based on its analyses,that these predictedboron and TDS concentrationsprovide a reasonablebasis Eor assessingthe impacts of the SPC project on boronand TDS concentrationsin the Poplar River System. As notedearlier, however,these values should be viewed as approximations,rather than absolute values.

TheCommission has reached the following conclusions concerningthe potential impacts of Cookson Reservoir and the SPC project on boronand TDS concentrationsin the Poplar River Basin. First, theprincipal impacts of bothscenarios on boron and TDS concentrations wi.11 occur in theEast Fork between the InternationalBoundary and the confluence of the East andMiddle Forks. In this area, the major impact will occur in thespring floodperiod when, prior to CooksonReservoir, boron and TDS levelshave traditionally decreased dramatically to average values of 0.5-1 mg/land 350-550 mg/l,respectively, as a result of spring runoEf waters containingrelatively low concentrations of theseconstituents. By contrast, water qualityin the East Fork inthe spring period withCookson Reservoir in place will be alteredbecause the traditional high quality spring runoff will be stored andmixed in the reservoir with water thathas accumulatedin the reservoir over past years.These inputs would include Low quality summerand winter inflows plus inputs from the SPC project. Water leavingthe reservoir via surface c)r groundwaterroutes will havebeen mixed in the rcservoir,and consequentlythe annual cycles in the East Fork will no longer be as apparent.The mean boron and TDS concentrationsin the East Fork at theBoundary are predicted to increase to around 1.4-1.6 mg/1 and 750-830 mg/ldurixg spring months with Cookson Reservoir operated inaccordance with the recommended apportionment. - 172 -

Nhenthe two-unit SPC plant goes into operation, the mean boron and TDS concentrations in theEast Fork at theInternational Boundary are predicted to increase to about1.9-2.4 mg/l and 900-1000 mg/l,respectively, during the spring. The predicted impact is reduce? as one goes downstream, as a resultof inflows of water Erom othertributaries not influenced by Cookson Reservoir. During tho remai.ningpt3rtion of theyear, meanmonthly concentrations of boron and TDS inthe East Fork at theBoundary for the SPC projectscenario are predicted to exceedthe predicted historicbaseline and predicted status quo meanvalues. 1'1 eva'lu3tinythe significance of these comparisons, it is appropriate to note, as dis~ussedpreviously, that measured values; between 1.975 and 1980 !Figures VI-6 to 1/1-13) !laveusually exceeded predicted values during Low flowmonths and have been lower thanpredicted valuesduring high flow months.The Comrnission notes the mean boron and TDS concentJ:ati.ons in the East Fork at theBoundary have been more constantover the annual cycleafter completion of Cookson Reservoir.

There1.ative impacts of the SPC plant are of smaller magnitude as onemove,s down the East Fork. As noted in Figure VI-18 thegener?i. trends are the same for all threescenarios in the East ~orknear Scobel7, Montarla. There is, however, much less difference betweenthe spring val.11es at thisstation than at theboundary under all threescenarios. The meanhistoric Sase'l.ine boron and TDS concentrations dur i;lg thespring are onthe order of 0.9-1.2 mg/l and 500-650 mg,/l., respe2tively,while the levels under the reservoir scenario -ire 1.2-1.5 mg/l and700-800 mg/l, respectively. The correspondingmean values for the SPC plantscenario range Erom about 1.3-1.8mg/l and 700-900 mg/l, respectively. During the remainder of the yea^: at this station,the mean boron and TDS levels ldnder the SPC plantscenario range Erom 1.9-2.9mg/l and 950-1150 mg/l,respectively, - 173 -

The SPC plantimpacts on boron and TDS concentrationsare notablyless once the waters oE theEast Fork mix with those from the MiddleFork (FigureVI-19). At this point,there is generally a slight projectedincrease in the mean boron and TDS levels throughoutthe year as a result of the SPC plant. The general trends with or withoutthe SPC plants,are, however, aresirnilar throughoutthe year. The springtime mean boron and TDS levels under the SPC plantscenario range from about 0.9-1.2 mg/l and 550-750 mg/l, respectively. This compares with thecorresponding historic baselineconcentrations of about 0.8-1.0 mg/l and 500-650 mg/l, respeztively.

At the lower end of thePoplar River Basin, near Poplar, Montana, theimpacts of, Cookson Reservoir and the SPC project on mean boron and TDS concentrations will be slight (Figure VI-20). The predictedspringtime mean boron and TDS concentrations under all threescenarios range from about 0.6-0.9 mg/l and 500-700 mg/l, respectively.

Thus, overall,the Commis;.on concludes that theimpact of the SPC plant and Cookson Reservoir on averageboron and ’TDS levels will be most significant in theEast Fork between theInternational Boundary and theconfluence of theEazt and MiddleForks. The averageboron and TDS levels below Scobey, Montana arenot expected tobe measurably different from historicbaseline water quality.

Irnpacts on Barley and Alfalfa Crops “l_”_l____”_

The Commission presented its bestestimates of critical boron and TDS levels in irrigationwater for thelong-term irrigation of severalselected crops in thePoplar River Basin earlier in Tables VI-17 and VI-21. These estimatedcritical levels areconsidered to be levels which would not result in crop yield reductions. For barley,the critical level is estimatedto be 0.5 to 1.0 mg/l boron; for alfalfa, thecritical levels are estimated to - 174 - be 1000-1300 my/l TDS and 5.5 mg/l boron.Predicted boron concentrationsfor the three scenarios illustrated in Figures VI-7 to VI-20 all exceedthe criticallevels for barley in several portions of the Basin,p2rticularly for months otherthan during the springperiod.

111 theEast Fork at theInternational Boundary, the predicted mean boron concentrationsexceed the estimated critical Level f3r barley durii1y nost monthsunder historicbaseline conditions, and during theentire year both with thereservoir in place and with thetwo-unit SPC project io? operation. During the months of Marchand April under historicbaseline conditions, when high qualityspring flows traditionally occurred, the mean predicted boron levelsare 0.5 and 0.8 mg/l, respectively, which are within therange oE critical. imron levelsfor barley. With thereservoic, but no plant in operation, mean boron levels during these months are predictedto increase to 1.6 and l.4 mg/l, respectively,while the concentrations with the SPC plant in operationare 2.4 and 1.9 mg/l, respectively. Irl thecase :3f TDS, thecritical level for alfalfa is onlyexceeded during a portion of winter under historic baseline conditi.ons. During thespring period, historic TDS lsvelsduring March and April were 360 and 470 mg/l, respectively. TD.S levels t-lilring March and April. r re increasedto 830 and 750 mg/l with the reservoironly, and to 1010 <-tnd 910 mg,/l, respectively, with the SpC plant in operation.

Further downstream on the East Forknear Scohey, above the confluence with the MiddleFork, the trends are similar to those observed atthe Boundary. However, the boron concentrationsare generally ;lightly lower overall,except during March and April. In this portion of theEast Fork Basin, the TDS levels are of more concern because alf3lfa, a cropsensitive to TDS, hasbeen irrigated with water from the East Fork, althoughthe Commission also notes that only 65 acres of alfalfa were irrigated in this Fork with PoplarRiver water during theyear of study. While thepredicted - 175 -

Tables v-1-24 and VI-25 indicate that predicted meat] boron concentrationsalong the Niddle Fork are wit.hl.n the critical. range .. . for barley crops, 3nd that TDS concentrations arc? wei.1 below the critical.range for alfalfa crops,under both the apportionnent and non-apportionmentscenarios a Tables VI-26 and VI--2'7 ,i.nciicat:.e that dredicted boron concentrationsfor the Boundary at, the West Fork are withinthe critical range for barleyyieLds under both the appor t ionmen t andnon-apport ionment scenar io TIcswevel:, the predictedLevels decrease to below critical. ranges zt f?redet.te, Montana. For %DS, the predicted mean levels i~nder.both - 176 -

apportionmentand nos-apportionment scenarios are well below the criticalrange fQr a1.Eal.h along theentire reach from the Boundary to Bredette.

IrnPact :3n Barley and Alfalfa Production

A:; indicatedin the previous section, the Commission does not antiripat,?that the yields of alEalfawill. be adverselyaffected by changesin water qu83litty resulting from theapportionment or the SPC project. On theother hand, since boronconcentrations are 3.ikel-yalready, at or abovelevels that wolxld have a detrimental effecton barley yie1.(-3s, any additionalincrease can be expected to have some adverse effiect onbarley yields. The effect on the producer will depend on a variety of factors,including: the type oE irrigation praztices used by theproducer; the av?ilabil-ity of sufficientquantities of water when it is requiredby the crop;the boron concentration of thatirrigation water as compared to that previouslyavailable; the relationship between boron concentrations inirrigation water and barleyyield; the quantity of barleygrown by theproducer; and Euture market conditions,particularly the c~>:;tsof fertilizersand the value of barleyrelative to alternate crops.

The Uses andWater Quality Objectives Committee concluded that"the 1975 crop acreagesfor the subbasins that will beaffected by the powerplant oper3tion" were as follows: Subbasin Bar ley .Alfalfa To ta 1 East Fork 0 65 65 PoplarRiver 45 1324 1369 Futuredemands for irr-iyation water are expected to begreater than present requirements. Water will be av3ilableunder the recommended apporti::,nment to meet significant new demands. - 177 -

T!le approximatecost implications on thebarley yield reductionspredicted to occur as a result of increasedboron concentrations i.n irrigation water areillustrated in Figures VI-21 and VI-22. TheseFigures are based on Figures 3 and 4 from the Uses and :,laterQuality Objectives Committee Report.These latterfigures were modi.fiedhere to take into account the assumption noted earlier in this sectionthat the concentration of boron in soil water will, on average, be twicethat in irrigationwater. This modification was necessary because the Committee had assumed that the boron concentration in soil water and in irrigati.onwater wouldbe the Sdine.

The relationship between theestimatld crop loss forbarley irrigated with water from theEast Fork and theboron concentration in theEast Fork atthe International Boundary is iLlustrated in Figure VI-21. For example, assumingthe histQric baseline concentration of boron in the East Fork atthe International Boundary was 1.25 mg,/i, a crop loss of approximately $18 peracre is projected if the averageboron concentration were toincrease to 2.5 mq/l. The Commission is notaware, however, thatbarley has been irrigatedalong the East Fork of thePoplar River.

The relationship betweenthe estimated crop loss for barley cropsirrigated with water from thePoplar River between the confluence with theMiddle Fork and theFort Peck IndianReservation is illustrated in Figure VI-22. Again,under the assumption that thehistoric baseline concentration of boron in theEast Fork atthe International Boundary was 1.25 mgjl, a crop loss of approxinately $8 per acre is projected. The Commission notesthat the Uses and NaterQuality Objectives Committee reportedthat a total of 45 acres of barley were irrigated in 1975 in this section of the PoplarRiver Basin.

The assumptions on which therelationships illustrated in Figures VI-21 and VI-22 arebased are consistent with thoseinherent - 178 .- inthe ear-Lier conclusions of theCommission in this section concerningthe projected impacts of the SPC project 01-1 water quality andbzirley yields. Two additionalassumptions inherent in these specific figuresare that the average price forbarley grain is $2.25 per bushel (1978 U.S. dollars)and that the yield ~f b;lrley at traceboron concentrations was 30 bushels per acre. TheCo~nmission n*>tcs khatmean boron concentration in the East Fork undernatural condit.i,onsal-ready exceeded trace levels.Figures VI-21 and VI-22 take these factors intoaccount.

The::? ar? many uncertaintiesin Some of theseassumptions, and for that re,2son the Commis:;ion regardsthe cost relationships il.Lust:ratedin Figures VI-21 and VI-22 only as approximations.The Commissionrecognizes that there are goodarguments that could lead to either lower orhigher cost estimates. As oneexampl-e, if the hist:ox-ic baseline averageboron concentrations were higher or lower thanthat indicated in Figures VI-21 and VI-22, a lower or higher efstimatedcrop Ioss, respectively,would be projected.The estimates inthese figures do, however, provide a generalsense of the costs that could occur as a result ,a€ i.ncre.3sedboron concerctrationsin irrigation water. When consideredin conjunction withthe acreages that are likely to be involved,they also provide a sense of the overall costs thatmight be attributable to water qualit.ychanges. ". 0-i I I " . .. 0 0.5 4.0 4.5

Figure VI-21 PredictedRelationship Setween Crop Loss forBarley Grown Along East Fork and Mean Boron Concentrations in East Fork atInterndtional Boundary (adapted from Uses .and Water Quality ObjectivesReport) - 180 -

" I -1"" l_-.--

1

In d 0 - 191 -

OTHER CONSIDERATIONS

Multipurpose"" ." W:llter Quali.ty Objectives-

At the Commission'spublic hearings, concern was raised as to the Board's recommended multipurpose water quality object' Lves. The Board suggest3dthat these objectives would apply atthe I.lternationa1 Boundary. They weredeveloped toprovide protection topresent and reasonablyforeseeable uses atthe point of use. The mard cautionedthat they should not be used asabsolute values of w,.-~terquality, but ratheras guides forassuring water quality p..atectic)n for water 1.1ses. The 3oarr7 a1:;o recommended thatthey silould be reviewedl and adjusted if nec::ssary, at a minimum of every fiveyears. The Commisgion notesthat the Uses and Water Quality 0i;jectives Comrnittee sugge;tedwater qualityobjectives €or anumber 0;:specif:ic uses (e-f~., xunkipal, iqdustrial, irrigation, aquatic l €e,etc:,) . However, only themultipurpose objectives recommended b> the Board were considered by the Commission.

The Board'sobjeztives are compared in Table VI-29 with the rnc:.jian valuesreported by theSurface Water Quality Committee for t!,eEast Fork at the International Boundary. Water qualitycriteria 0; objectives, either proposed or in effect, €or Saskatchewan and M~ntanaare also presented forcomparative purposes. The Commission nc tes that the Board's proposedmultipurpose Dbjectives, S:>skatchewan's c:riterin and Montana'sobjectives, are sll sometimes e::.:oeded by natucal..'!~occurring levels €or some of theparameters. TI.'? Commission also notesthat the Board did notpresent proposed okjectivesfor numbera of other parametersdiscussed in the Board Report .

Becausethe Commission considers it unrealisticto recommend objectivesthat exceed natural levels, it concludesthat theBoard's multipurpose objectives should be consider2das a - 182 - partial and provisional list of water quality guidelines at this time. I€, after additional monitoring, it appears that any water qua-lity parameter is likely to impair an existing or reasonably foreseeable use, specific water quality objectives should be adopted for the psrameters so identified. - 183 -

Table VI-29: A Comparison of Board's Recommended Multipurpose Water Quality Objectives for the East Fork at the International Boundary with Median Measured Values; Saskatchewan Criteria and Montana Objectives

- BOARD EAST FORK MULTI - MEDIAN VALUE SASKATCHEWAN MONTANA PARAMETER PURPOSE AT INTERNATIONAL CRITERIA* OBJECTIVE^ BOUNDARY~ ___-__OBJECTIVE "" "___ "- r\lurninum 0.1 0.02 (dissolved)

Ammon i a 0.2 - - 3.02 (f re?) (0.02- aquatic -Life)

Cadmium O.OOL2 0.01 0.01 0.01 (0.0004- aquatic f4 life)

Chromium 0.05 0.01 0.05 0.01 (0.05- aquatic life)

Copper 0.005 0.01 (dissolved)

Copper 1.0 0.02 0.02 0.1 (total) (90th percentil?) (0.02- aquatic Life) Fluor ide 1.5 - 1 .5 - Lead 0.03 0.02 0.05 5.0 (0.05- drinking water Mercury 0.0002 Below - (dissolved) Detection (0.00005- Lilni ts aquatic life) Table VI-29 (continued) ""

BOARD EAST FORK MU LT I- MEDIAN VALUE SASKATCHEWAN MONTANA PARAMETER PURPOSE AT INTERNATIONAL CRITERIA2OBJECTIVE3

-. OBJECTIVE BOUNDARY' "

Mercury 0.5 (wholefish)

10 0.84 - - (10- drinking water)

Dissolved 5 4.4 5 - Oxygen (minimum (minimum-spring) (4- -Apr. 10 drinking -May 15) water)

4 5.2 (minimum (minimurn-rest of -rest yr.1 of yr.)

SAR 10 3.84 8

Sulfate 800 2194 200 (0.017- aquatic life)

Zinc 0.03 0.01 0.05 2.0 (0.003- aquatic life)

Temperature"natural" 0.5-1.2 no more than (OC1 (Apr. 10 (spring ; median 3O above -May 15) = 0.6) "natural" <30 (res?: 21.5 of yr .) (maximum-rest of Yr -1

PH 6.5 8.14 6.5-8.5; 4.5-9.0 (minimum) less than - and less 0.5 from than 0.5 background above "natural" - 185 -

Table""- VI-29 (conki nued)

_. - "" -I_ "X."" "" ~ "" __ BOARD EAST FORK MULTI-MEDIAN VALUE SASKATCHEWAN MONTANA PARAMETERPURPOSE AT INTERNATIONALCRITERIA OBJECTIVE3

"."""~""""~._I"-.."""-."-- "."""~""""~._I"-.."""-."-- OBJECT1V4 BOUNDARY'___. -__.

Coliform (maximum density) -f ecai 430/100 ml lOOO/lOO ml - (9 of 10 samples)

-total 20, ooo/ 430/100 ml 5000/100 ni 1000,/ LOO ml (9 of 10 loom1 samples)

IAll measured values at International Boundary are pre-reservoir median values (mg/L), unless otherwise noted.

2Saskatchewan criteria are based on multiple use requirements, 3Montana objectives are based on irrigation requirements; most sensitive use requirements are also indicated in parentheses,

'Average of median values for each season of the year. - 186 -

Air" Quality Aspects "

The Poplar River: Water Quality Reference did not request the Commission to address the e€fects of the SPC development on air quality. However, in view of the possibility of water quality impacts as a resillt of atmospheric emissions from the plant, as well

The Board, usinci several air pollution models, presented a brief analysis of potentiaL air poL1ution impacts and reported that annual ground level maxinlum annual concentrations of SO resulting 2 from pl.ant erniss ions wou.~dbe approxinately 1.2 ug/m3 in the area about, 15-24 km (10-19 mi) northwest of the proposed 600 MW plant. An annual mean concentrat ionof about 0.5 ug/m3 was predicted to occur in the Scobey, Mont.ana area. Maximum concentrations predicted €or total suspended particulates (TSP) and NOx, respectively, as a result of the proposed 6CO MW plant are 0.05 ug/m3 and 0.4 ug/m 3 , respectively. The maximum predicted concentrations are expected to occur in the northwest and southeast direction from the plant site. These concertrations correspond to depositional rates 2 2 of 0.032 g TSP/m /yr, 0.76 g S02/m /yr and 0.145 g NOx/m 2 /yr for the proposed 600 MW plant.

Using these valces and various air pollution models, the Board estimated the annual quantity of TSP deposited within a 70 km (43 mi) radius of the proposed plant would be about 1364 metric tons (3 million lbs). The annual SO2 and NOx deposition rates in the same area would be 34,000 metric tons (75 million lbs) and 11,365 metric tons (25 million lbs), respectively. The Board noted that these calculated TSP and SO2 rates were about three times the maximum annual estimates of the U.S. EPA, while the NOx rate was about five times the EPA rate. The Board, therefore, concluded that a "considerable portion of the fine particulates emitted must therefore be deposited beyond (the) 70 km (radius)It.

In it.; assessment of the fugitive dusts likely to a;:ise from the "mining operation and activities around the Poplar River Power Plant," tile Soard concluded that the total annual emissions would be about 4670 metric tons (10 million lbs), with the mine operations contributing about seven times as much dust as the plant. As was t11e c3se for emis:;ions from the stack, the maximum concentrations of dust were predicted to occur in a west-northwest and east-southeast direction from tile plant area.

In cxaQining the impact of these projected emissions O:I wat-.+r quality in the Cookson Reservoir itself, the Board concluded the emissions would result in a negligible addition of TSP and Eugitive dust, as well 3s horon and selenium, to Cookson Reservoir. This corresponds to about 4,600 kg (10,200 lbs) of TSP and 5.5 kg (12 Lbs) of boron being deposited directly onto the reservoir surface per year. The Board suggested that when the volume of the reservoir was considered, (41 bilLi.on liters at the full supply level), the projected increases in TDS and boron would 55 "insignificant."

The Commission concurs With this genera1 conclusion, although it expects that at smaller volumes of water in Cookson Reservoir, the t,ransport of materials deposited on the land surface in the Basin to the reservoir ~ouldproduce somewhat higher estimates of the input oE atmospheric emissions on reservoir water quality. It also notes that materials other than boron and other constituents of TDS are usual1.y emitted when lignite coal is burned. Some constituents, such as sulfur dioxide and oxides of nitrogen, while unlikely to influence water quality in the Poplar River Basin, will represent another contribution to the continental problem of acid rain. - 188 -

Prior Notice and Consultation "- " "" - ""

This Reference has been particularly difficult for the Commissioq. This was due in part to the fact that construction of the Paphr River Project began before the Reference from the Governments was received. In addition, had studies been undertaken prior to commenceaent of construction, better baseline information would have been available, and if the studies showed that problems would likely arise, corrective measures could have been taken prior to construction. To some extent the process of changing the project design in response to preliminary study results did occur, but the potential for rnajor changes in project design is severely limited once a project is already under construction. This leads the Commission to comment once again on a matter it considers of extreme importance to the United States and Canada; that is, the procedure of prior noice and consultation. Had the procedure of prior notice and consultation been adequately followed in this case, the Commission believes that it would have been to the mutual advantage of both countries.

The Commission has discussed this matter in other reports and in correspondence wi.th the Governments, most recently in the Report on Water Apportionment in the Poplar River i3asin. However, the Commission wishes to emphasize the need for Governments to take the necessary steps to assure that mechanisms are in place to provide adequate prior notice and consultation regarding proposed projects having potential transboundary implications.

Simultaneous Consideration of Water Quality and Water Quantity

Throughout the Commission's consideration oE the Poplar River matter, both during the apportionment study and the current water quality study, it has been apparent that in future apportionment References, water quality and water quantity issues - 189 - should be consideredtogether. Water quantityand water quality issues are oftenclosely related to oneanother. This is particularly true in cases involvingthe apportionment of streams such as the Poplar River,which have highly va.riable seasonal flows coupled with generally poor natural water quality.In such case? the impoundment of water inupstream reservoirs will invariably affect the quality of water receiveddownstream due to the withholding of relativelyhigh quality spring water, andthe mixing Over time of this water with water ofdifferent quality, and the naturalevaporation of water inthose reservoirs. Unless these water quality impacts are consi.deredalong with quantity impacts, it is not possibLe to assess the overalli.rnp1ication.s of apportionment in the downstreamportion of theBasin. Consequently, it is Ear more difficult to developan apportionment that provides each country wi.th an equitable share of the beneficial uses of the waters of the Basin beirlg considered. - 190 -

CHAPTER VI1

PROPOSEDCOURSE OF ACTION

up to thispoint the Cornmission has focused on the baseline water qualityconditions in the Poplar River Basin, the existing and reasanablyforeseeable usw inthe Basin, the water qualitythat is required by theseuses, and the likely transboundary water quality implications of bot!1 therecommended water apportionmentand the SpC power project.This was thefact-finding portion of thestudy. The Commissi(3rl now considers tile centralquestion of the Reference, which is therelationship between the above Eindingr; and Article IV of theBoundary Waters Treaty of 1309.

In theReference, the Commission was asked to make recommendations to assist Governmentsin ensuring that the provisions of Article IV are honored. Article IV reads,in relevant part, as follows: "It is furtheragreed that the waters herein deEined as boundary waters and waters flowing across theboundary shall. not be polluted on either side to the injury of health or propertyon the other."

It is important to notethat Article IV doesnot say that there shall be notransboundary po1I.ution but rather it requires thatinjury not result from such pollutioq. Thus,the Commission concludesthat Article IV doesnot require nondegradation per se. In some cases the upstream countrycould degrade the water quality of a transboundary stream withoutcausing injury to health or propertyin the downstream country; in other cases, anydegradation of water qualitycould cause suchinjury. There is no generalrule - 191. -

to define the degree (sf "pol.lution" that consti.tutesa violation of Article 117 of the Treaty. As A consequence, each si tuation must be examined on a case-by-case basis and the course of action that is selected will. reflect the particular circumstances Oi the case.

In addition, it is clear that many of the i-ssues raised by .this Reference dre i.nextcicably tied to the issue of water apportionment tnat the Commission reported on in 197'3. Indeed, in this situation, where countries are seeking to increase their use of water i:~a basin where water is both scarce and of relatively poor: quality, the Comnissi.on believes that the issues of equitable apportionment and the 05l.igations of Article IV must be examined at the same time.

Reductions iq water quantity resulting from an apportionment can adversely affect downstre'2m uses. However, the Commission does not mnsi.?er such reductions in water quantity per sc to be pollution within the neaning of Article Iv. The Commission believed that these nnatters should be considered within the context of appvr tionment. In some cases, such impacts could be a basis for not apportioning water for a particular use; in others, mitigation, compensation or other alternatives may be required to achieve equity; and in others stil.L, no additional measures may be necessary .

The Commission recognized i.n its Apportionment Report "that major economic, demographic, technological, environmental and other changes may occur in either the iJnited States or Canadian portions of the Poplar River Basin. These changes may suggest patterns of water use different from those envisaged at the time of the Board's study." The Commission believed then "that the apportionment agreement shou1.d irlcl.ude provision for review, to ensure continuing equitable utilization of the waters of the Poplar River to the benefit of both countries." The Cornmission now reiterates its recommendation for periodic review of the apportionment agreement. - 192 -- - 193 - and r.3ise issues regarding both the obligations of one country to the other and the legitimate expectations of individuals in both countries. They also raise issues regarding the relationship between emerging principles of international law, such as equitable apportionment, and the mutual obligations of Canada and the United States embodied in the Boundary Waters Treaty of 1909.

When considering the issue oE equitable apportionment, one must be concerned with the uses in both the upstream and downstream country. Because equitable apportionment focuses on uses, it is clear that consideration must. be given to both water quant-ity and water quality. In this report the Commission is focusing on the potential impacts of Canadian uses on existing and reasonably foreseeable uses in the United States since this is necessary to address the questions raised in the Reference.

In developing its recommended apportionment in 1975, the Commission included in its considerations the Helsinki Rules on the "Uses of the Waters Df International Rivers," adopted by the International Law Association in 1966 as a useEul. statement oE the emerging principles of international law on this subject. The fundamental principle of equitable apportionment as expressed in Article IV of those Rules, reads as follows: "Each basin State is entitled, within its territory, to a reasonable and equitable share in the beneficial use of the water of an international drainage basin." For information purposes, other Articles of the Helsinki Rules which amplify on this principle are contained in Appendix J.

The Commission finds that customary international law has not developed to the state where a precise or binding formula for the apportionment of water in transboundary rivers can be applied in any given case. Indeed, such a formula applicable to a11 cases may - 194 - never be developed. However, certain general principles are evolving and a review of the Helsinki Rules is useful in considering apportionment issues. In its previous report, the Commission recommlr3nd?d an apportionment, which it believed was the most equitable and practicable at that time in light of the factors to which the Commission was limited by the Reference and the facts avsil..able to it.

The Ccmmission notes that if the process of apportionment is to be equitable, it must take into account the water quality impacts of uses i? one country on uses ii? the other. For the United States and Canada, Article Iv of t!le Boundary Waters Treaty defines the obligations oE each country to the other regarding water quality, and any uses of water made under an apportionment agreement should not violate the provisions of Article IV of the Treaty. Because Artic'Le .IV can act as a constraint on upstream development in apportionment case:; , as well as i? non-apportionment cases such as the Garrison Diversion, there is no absolute right for the upstream country to make a desired use ot water arising in its territory if that ase woilld result in injury to the downstream country, At the same time, the process of apportionment is one of cooperation, and therefore each country should take a reasonable position to accornmodats uses in the other country so long as it continues to receive an equitable share of the beneficial uses of the waters that are available.

These views are based upon a number of considerations. The Commission notes the longstanding and farsighted mutual commitment of the United States $lnd Canada to protect water quality in both countries. This commitment, as has been demonstrated in United States-Canadian practice in the Great Lakes and elsewhere, extends both to the protection of the more traditional economic uses of water as well. as to the protection of less traditional but increasingly more ccmrnon recreational, scenic, natural preserve, and - 195 - ecosystem research uses, Both Governments have recognized the intrinsic value of maintaining water resources in their natural state. In the Commission's view, the stated purpose of the 1978 Great Lakes Water Quali.ty Agreement: "to restore and maintain the chemical, physical and biological integrity of the Great Lakes Basin ecosystems," is a specific example of the Governments' commitment to the protection of less traditional values associated with water. At the same time, the Commission recognizes that all beneficial uses may not be possible, particularly in areas such as the Poplar River Basin where water is both scarce and of relatively poor quality. Indeed, it is inevitable in water scarce regions where the upstream country has used relatively insignificant amounts of wa.ter, as is the case in the Poplar River Basin, and then begins to exercise its right to use a fair share, that this may cause dislocations downstream which can manifest themselves by causing adverse impacts on existing uses. While the process of developing an equitable apportionment does give due consideration to existing users of water, it also recognizes the right of each basin country to a reasonable and equitable share in the beneficial uses of the waters of a basin.

The Commission believes that when water quality or quantity changes do occur in one country as a result of new uses in the other, some provision should be made to all-ow those who may be adversely affected by the changed circumstances to seek compensation. Such a provision can he useful. in making the process of equitable apportionment more acceptable to those who may be affected. Such cooperation and accommodation will facilitate the process and assist Governments in taking advantage of changed needs in a basin context in water short areas. The Commission believes that such a provision should be made both in cases such as this where the new uses are in the upstream country and in parallel cases, in this or other basins, where new uses in the downstream - X96 -- The Commission hasexamined thepotential transboundary waterquality effects of thealtered transboundary flows called for in the recommended apportionment and of the SPC power pcoject with .the above considerations in rnind. The Commission recognizesthat there wi.I.1 likely be some adverseeffects Erom changes in water: qua.’lity and quantity. AS discussed in theprevious chapter the reduct.ion in the amount of watercrossing the boundary is expected to adverselyaf€ect the maintenance of theexisting biological community in theEast Fork of thePoplar River. TheCornmissio;1 considers this an adverseeffect of waterquantity reductions and, therefore,does not propose measures to ensure compliance with Article TV because it does not faLl within Article IV. Howeverc, because this effect was not known and, therefore,not considered by the Commission in theApportionment Report, it now believesthat this effectshoold be considered by Governments.Other water quantityconsiderations both beneficial and adverse which may need to be similarlyaddressed are in partsuggested by theApportionment ~eport,e.g., (1) new informationregarding the effects of the project (2) effects of possiblefuture reservoirs, (3) the feasibility of Canada using its apportioned share of water, (4) the resu1t.s of plans of mutualadvantage, and (5) differences between actual and projectedflows.

In addition,the projected increased boron concentration will. like:lycause a smallreduction in yields of irrigatedcrops such as barley and wheat on therelatively limited acreage on which thesecrops are now irrigated. The Board reportedthat in 1958 it wasknown thatthere were 45 acres oE barleyirrigated immediately below theconfluence of the East and Middle Forks. It is not certain howmany acresover the years may have been similarly irrigated in areasthat might be affected by the SPC project. However, in thepublic hearings held, no others were identified. Therefore, it may be assumed thatonly a verysmall acreage is involved. A somewhat larger impact would be expected on barley and - 195 - wheatyield.; if they were to be irrigatedalong the East Fork of the PoplarRiver where none i:s known to havebeen irirgated. It is not known! therefore,that tnese are presentlyfeasible crops inthis area E%>r irrigation. No adverse impact on alfslfayields are expected.In addition, the Commission be1.ievt.s that th;3 tltges and range of reasonably foreseeable uses in Montana identified in Chapter VI c7f thi.5 rep~rtare expected to remainsubstantially unchanged.Figure3 TJI,..-2L and VI-22 in Chapter VI indicatethe apprQximate d~llarLosses that (are predicted to occur as cc)nseql.lenc:e of the effects of increasedboron concentrations on the yield of baciey Such lossc~sI when consideredin conjunction with theboron collcerlt..ratiorls predicted to occurand the limited number cjf acres l-ikely. to be invoLved, may be described as minor. - 199 - appi.3rtionment recommended in 1975 remains equitable and should be adopt.ed by the United States and Canada and that Article IV of the Treaty wi.1.1 not be violated in so doing. The Commission notes that this concl.clsion with regard to the apportionment is based upon av2ilabLe information and suggests that the matter discussed earlier in this Chapter be considered by Governments in their discussions on t.hc 3ppor tionment clues tion.

Finally, the Commission concIt1des that themost appropriate course 13€ action €or the Governments to take in this case to ensure that Article IV i.s not violated is one which includes a number of interrel3ted provisions. It is essential that this course of action i!?c\ude water quality objectives designed to protect water users downstream, measures to help resolve the many uncertainties associated with existing and future water quality as well as the water quality requirements of downstream uses, and provision for additional mitigation should that he found necessary. In addition, it is essential th.3t adequate provision be made €OK assisting, and where appropriate compensating, those who may be adversely affected by the new regime. The Commission believes that implementation of these provisi.ons will fully satisEy the mutual obligations set forth in Article IV of the Boundary Waters Treaty and will assist in assuring that the apportionment recommended in 1978 remains equitable to both countries. The Cornmission believes that the foll.owing course of action contains these essential. provisions and recommends that it be adopted by the Governments of the United States and Canada. - 200 -

This provision follows from theCommission's Conclusion that waterusers who believethat they havebeen adverselyaffected by wateruses in the other countryshould have an appropriate forum in which theycan seek, compensation. The Commission considersthat til(? costs associated with assistingthose users to adjust to the new conditi~nsshou1.d be treated a!; one factorto he considered when developing an equl tableapportionment and in this case it believes thatthe new wer (~askntshewanPower Corporation)should consider compensation to downstr.cam users a,s a normal cost of doing business. The Ccmnissionbel.ieves t!?at this mechanism need be in placeonly f:>r a limitedperiod of time,perhaps for five to ten year:;, 'after the commencement of the operation of the two unit (600 "rJ) power plarlt, althoughthe period covered by any compensation settl.ernentshould not be restr icted. The Commission alsoconsiders that: 1.mp sum sett1,ementsto individual irrigators who cail demonstratethat they are adversely affected should be considered and t.h3t the sum t.o be paid could be determined in many ways inc1.uding reduc:t:.ions in thepresent value of theproperty or projected losses in income due toprojected reductions in cro,p yields. In addition,the Cornmission believesthat this mechanism should be concerned only with effects within therange of those projected in this report. I€ it turnsout that there are impacts greaterthan those projected, they should be considered within the context of provision 2 of this proposedcourse of action. In this regard theComnission ngtss thatthe establishment of such a mechanism does not in any way prejudge whether or notadverse effects will actually c)ccur.Indeed, given the uncertainties i,n ti1i.s case, it is entirelypossible that no adverseeffects on existing uses will be experienced. The establishment of an appropriate mecharism assures only that if a cLairn i,s made a forum will be available to deal with thematter. Any speci€icclaim, of course, will have to be judged on its merits. - 201 - trust fund. In addition, the Commission notes that the American Bar Association and the Canadian Bar Association have recommended that the United Stater; and Canada enter into a treaty which would provide citizens of each country access to the courts of the other in transfrontier pollution cases and would assure that they receive equal. treatment with citizens oE the other country. Although it may take some time to achieve, such a treaty could provide an ongoing mechanism along the boundary to deal with cases such as the Poplar River matter.

The Commission believes t!lat the mechanism most adequately meeting the needs for adjudication of compensation in this case would be a Si-national cLaims commission which would determine a fair basis for compensation based on the laws of the two countries, international law, or other agreed bases as it may deem appropri.ate. Such a mechanism would have the benefit of providing a uniform basis for compensation and would not add a cost burden to those who feel themselves aggrieved should the alternative be that they must take the cases to court separately.

The Commission wishes to emphasize that this recommendation is not an endorsement the use of compensation rather than mitigation as a means of dealing with potential transboundary effects from degradation of watt?r quality. Given the specific facts of this case, however, including the relatively minor water quality impacts that are expected, the Comnission believes that compensation for the limited purpose discussed abov? is appropriate when considered within the context of this proposed course of action. - 202 -

The Commission believes that the projected water quality impacts downstream are dcceptable under the particular circumstances of t-his case. However, because of the large number of uncertainties regac~3ing.the impacts lot the apportionment and the SPC project on t!~ePoplar River systern, the Cornmission believes that it should be ,zlearly understmd that if the impacts are more severe than now projected, additional measures to address these impacts will be required and should be undertaken.

The interim objectives recommended by the Commission are based 011 severs1 factors including: the alternative objectives .. ci1.scussed by the International Poplar River Nater Quality Board and it-s IJse:; and Objectives Committee; Statements received at the public hearillgs; the recommended water quantity apportionment; the requirements for existing and reasonably foreseeable uses of water on both sides of the International Boundary; the measured and computed baseline concentrations; and the computed concentrations for scenarios with the two-unit 600 megawatt SPC plant in operation. The Commission suggests that the long-term average - 203 -

concentrations be calculatedas five year rolling averages and that they be based onmean monthlyflows, with at least oneboron and one TDS sample to be takena-t intervals of not more than 31 daysduring the March toOctober period.

Based upon theprojected impacts the Commission recognizes thatthese recommended interim boron objectives will not, in themselves,provide complete protection for irrigators who havo used waters from thePoplar River system to irrigate barley or wheat. Otherfactors may or may notalleviate the effects on cropyields o€ themoderate increases in boron concentrationspermitted by these interimobjectives. Compensation issuesare not addressed in this paragraph.Although these interim TDS objectivespermit a moderate increase in thelong-term average TDS concentrations no adverse impacts on existinguses or reasonablyforeseeable uses are projected. The Commission belizvesthat, under thecircumstances, these recommended boron and TDS objectives will assist in ensuring thatthe provisions of Article IV of the Boundary WatersTreaty are honored.

In previousReferences dealing with Article IV of the Boundary WatersTreaty, the Commission has recommended waterquali-ty objectivesfor specific Boundary and Transboundarywaters. In effect, these recommended objeztives have reflectedthe Commission's judgment as tothe degree of degradationor "pollution" that could be toleratedbefore "injury to health and property'' would result. Such is theintent in this report. The Commission believesthat mitigation will be necessary if theobjectives are exceeded unless theimpacts on uses from suchexceedence are not greater than those anticipated in settingthe present objectives. The Objectives,once adopted by Governments, are a measure of whetheror not the provisions of Article IV of the Boundary WatersTreaty of 1909 are being satisfied. Water qualityobjectives can equally well be viewed as one of theconditions of an equitableapportionment. Such - 204 - objectives, when applied to transboundary streams, provide protectionfor benef i.cial downstreamuses while allowingbeneficial 1.1p:;tream uses to the extent that thecumulative effect of these upstream asea does not cause the objectives to be exceeded. Con:.;equently, the objectives become benchmarks that help define the +.Lrdm?work . - whi%-:hinfluences the mannerin which the beneficialuses of t.hc water resource are to be shared.

The Commission is pleased to note that the Governmentshave

established ;i Poplar RiverCooperative Monitoring Arrangement to monitorwater quality and water quantityin the Poplar River System. The bilateral group recommendedabove could perhaps build upon the committee established underthis arrangement. The duties of the bilateral group should includethe following:

(a) Oversee the monitoringactivities being conducted in the Basinand recommend changes in these activities as appropriate;

(5) Co-ordi.nateand initiate the studies necessary to furtherclarify the impacts of the SPC project on Poplar Riverwater quality and the effects of water quality on water uses in the Basin;

(c) Periodicallyreview the interim water quality objectiveswithin the overall B3sin context and recommend new and revisedobjectives as appropriate; - 205 -

(a) Recommend additional mitigation measures, if such measures are found to be necessary, to meet interim or revised water quality objectives;

(e) Review existing contingency plans for accidental spills of materials associated with the SPC project into the Poplar River System; and

(E) Report on a regular basis concerning all water quality matters referred to it.

This group could also undertake the periodic review of the apportionment that was recommended in the Cornmissson's 1978 Apportionment Report .

The Commission considers the Poplar River Cooperative Monitoring Arrangement to be a very positive step that wil.1 help ensure that the eE€ects of upstream uses on the quality and quantity of both surface and groundwater are adequately monitored. The Cornmission does, however, suggest that the monitoring network be expanded or modiEied to ensure that: (a) the responsibility for collecting water quality data from the Middle Fork of the Poplar River at the Boundary be shared between the United States and Canada so that water quality objectives can be developed based upon data that are generated in a mutually acceptable manner; (b) the monitoring of streamflow and water quality on the East Fork above Cookson Reservoir and on Girard Creek be done so as to provide an adequate basis €or determining the quantities of water and monitored chemical constituents enteri.ng Cookson Reservoir by means of these tributaries; and (c) the water quality and levels of Fife Lake be monitored so as to provide a better basis for assessing the impact of this Lake on water quality in the Poplar River System.

The Commission suggests additional investigations to clarify the impacts of the SPC project on the water quality of the - 206 -

PoplarRiver System and the effects of waterquality on water uses in the Basin. It believes it is essentialfor the bilateralgroup +. .. L(~attempt toensure that the necessarystudies are designed so as tc> est::3i11ish field criteriafor assessing the degree of crop damage a:;sociated with excessive boronor TDS concentrations. It is de:;Irahl.e to obtainsite specific information on: the relationships betweenstreamflow and theconcentrations of boron and TDS at streamflows af less than 0.0142 m'3 /s (0.5 cfs) in thePoplar River Basill, which i.;; the minimum flow used in the Board's models to make water qualitypredictions; the relationships between the concentrations of TDS and boron in irrigationwater with the (3o~~centt-n%i!.,nsof TDS and boron in soil water in irrigatedsoils along the Poplar i=tiv?r System; therelationships between soilwater concent.ratir3ns of TDS and boron and visible signs of crop damage for irrigatedfields al.ong thePoplar Ri.ver System; and the re.Lati.onshipsbetween soil. waterconcentrations of boron and the concentr?tions of boron in the tissues of irrigatedplants.

me Clommission alsosuggests that the bilateral group initliate orencourage one or more fieldexperiments to help assess thedegree to which cropyields in thePoplar River Basin are Kelated to concentrations ofboron and TDS in irrigationwater, concentr?tions of boron and TDS in soilwater, concentrations of boron and TD; in plant tissuc, and visible signs of crop darnage.

The Cornmis:;isn beli?ves that this bilateralgroup should co:Isidc_'c the development. of new or revisedwater quaLity objezt.i,ves for the Pop]-ar River System. '!?here areseveral considerations which the bilat.era1group could use i.n developingwater quality objectives. One consideration is the use of waterquality measuremeqts on theMiddle Fork a:; a startingpoint in establishing objectives for theEast Fork. Another consideration is thatthe flow and waterquality data for Girard Creek and the East Fork above Cookson Reservoircould provide information as to a "moving" or - 207 -

"floating" objective based on the balance between reservoir inputs and outputs. A further consideration would be the possibiLity of objectives for the entire Poplar River Basin. The bilateral group could a'Lso consider the merits of recommending objectives based on the combined Lc1c)'ws of the Middle and East FDrks. The Commission believes that this latter approach could provide an incentive for reducing boron and TDS levels in the East Fork, while at the same time adding another dimension to the recommended apportionment. All of the above approaches have some potential and the Commission encourages the bilateral. group to consider these possibilities when recommending the adoption of new or revised objectives.

The Commission notes that equitable apportionments of water resources between countries are entered into by the Governments of the countries concerned. They reflect the Governments' best judgment as to what is a reasonable and equitable sharing of the beneficial uses of the available water. Often, as in the present case, this may result in adverse effects on existing uses. Some of these effects may be elirninated or substantial.ly alleviated by means of changed practices by the water user. Since each Government has a stake in the success of the apportionment, the Commission believes it incumbent on each Government to take all reasonable steps to provide technical advice and other appropriate assistance to water users in its portion of the Basin. The Commission believes that existing U.S. governmental agencies already have the power and the authority to extend such assistance and, indeed, may already be engaged in such help. The Commission here only brings to the attention of governments the importance OE timeliness in responding - 208 - t.o the present situation and it is not recommending the imposition oE a new burden. The attention of a similar Canadian resgonse is not reque.;ted because as far as the Commission is aware there are no farmers usi:?g water to irrigate in the Canadian section of the East F:>rk Basin. This provision will assist in ensuring that water users who are affected by apportionment will not be forgotten when Governments atterr.pt to maximize to the extent possible the beneficial ares oE an international river basin. - 209 -

Signed this 19thday of January 1981 as the .InternationalJoint Commission's report tothe Governments of the TJnited States and Canada on Water Quality in the Poplar River Bas i n.

:I Charles R. Ross Jean R. Roy - 210 -

A P PEWD IX ''.A"

TEXT OF REFERENCE TO THE INTERNATIONAL JOINT COMMISSION

On August 2, 1977, the Secretary of State for External Affairs for t!le Government of Canada and the Secretary of State for the Government of the United States sent the following Reference to the International Joint Commission, Canadianand United States Sections of the Commission:

L 5ave the honour to inform you that the Governments oE Canada and the United States have agreed, pursuant to Article IX of the Boundary Waters Treaty of 1909, to request the International. Joint Commission to examine into and report upon the water quality of the Poplar River, irlcludigg the transboundary water quality implications of the thermal power station of the Saskatchewan Power Corporation and its ancillary facilities, including coal-mining, at a site near Coronach, Saskatchewan, and to make recommendations which wouLd assist Governments in ensuring that the provisions of Article IV of the said Treaty are honoured. In this context, the Governments note both the water apportionment studies conducted by the Commission and the PDplar River Task Force of its International Souris-Red Rivers Engineering Board, environmental. studies undertaken or proposed by the Saskatchewan Power Corporation and the Governments of Saskatchewan and Canada, and the environmental studies being undertaken by the State of Montana and the United States Government. 1'1 addition, the Canadian and United States Governments have established an international water quality monit.ori11g network in the Poplar River Basin. For the information of the Commission, the Governments further note that on April 29, 1975, the Saskatchewan Power Corporation was issued 3 licence by the Government of Canada, under Canada's International River Improvement Act, accompanied by an exchange of letter between the federal and provincial governments, to construct, operate, and maintain a dam on the East Poplar River in Saskatchewan to contain water to be used in the operation of a thermal electric power piant. Conditions of this licence include: A) Com2liance with terms and conditions relating to water apportionment as may be imposed by the Federal Minister of Environment, following recommendations by the Commission and acceptance thereof by Canad? and the United States; - 211 -

B) Construction,operation and maintenance of the improvement by t?le licenseein such a manner as shall. notcontravene theBoundary Waters Treaty Df 1909; and

C) Monitoring,by the licensee, of water qualityand water quantityand reporting to the sflid Minister as and when reques tpd. In this application to theCanadian Government for this l.icencp, the Saskatchewan Power Corporation committed itsel€ to carry out a ~iderange of water quality studies, sane of which are presentlyunderway.

InIiqht of the above, the Governments request that the Comnissionzxalnine into dnd reprt uponthe fqllowing matters regarding the ~32larRiver Basin:

1) The gresent state of water qu3lityincluding the fluctuations irl water quality,with particular ernphasi~; on the waters of the East Poplar River;

3) The tlature,location and significance of Eisheries and wildlifedependent on the waters of the Poplar Xiver;

4) The aature andlocation of existingand reasonably foreseeable w3ter uses;

5) The effects onpresent water qualityand consequent eEfects on the user; identifiedin paragraphs (3) and (4) above, which would result from:

(a) changesin the flow regime of the PoplarRiver if apportionment of the waters of the Poplar River is made as recommendedby the InternationalSouris-Red RiversEngineering Board's Poplar River Task Force in its Report of February 6, 1976, or as the Commission may otherwiserecommend;

(c) implementation of 3ther reasonably foreseeable developments;

6) Significanttransboundary impacts of the Saskatchewan Power Corporation's thermal powerstation and ancillary - 212 -

facilities, including coal-mining, and of reasonably foreseeabledevelopments in eithercountry on thewater quality and waterlevel in thesurrounding aquifers;

7) Such othermatters as the Commission maydeem appropriate and relevantto water quality.

In theconduct of its investigati.c~>nand theprep.aration of its report,the Cornmission shall make full use of information and technicaldat3 heretofore available or which [naybecome avaihthle i? eithercountry during the course of its investigation,including relevantstudies on thewater quality oE thePoplar River carcied outor to be carriedout by Governments and the Saskatchewan Power Corporation.In addition, t4e Commission shallseek the assistance, *3s required, of specia'llyqualified personnel in Canada and the UnitedStates. The Governments shall naice availableor, as necessary,seek the appropriation of the funds reqairedto provide the Commission promptly with theresources needed todischarge the obligations under this Reference fully within thespecified time period. Tne Commission shalldevelop, as early as practicable, most projections for thestud.ies underReference for the information of Governments .

This examination and report i.3 to be based upon a 600 megawatt facility.Authorization as been granted by the Government of Saskatchewn forthe first 300 megawatt unit. It is ankicipated that theSaskatchewan Power Corporation will, in the near future, seekauthorization from the Government of Saskatchewanfor construction of a second 300 megawatt unit. The coalreserves in the Coronach areaare considered by t!le Saskatchewan Power Corporationto be suEficientto support a 300 megawatt faci-1-ity; however, thereart? at this time no firmplans to proceed with, furtherexpansion. If, at a futuredate, the Saskatchewan Power Corporationindicates a firmintention to expand thethermal power station beyond two units with a totalcapacity of 600 megawatts,the Commission shall.reactivate its study program to examine such plans consistent with thefactors enumerat+?dabove, including impacts on thebasin of any associateddiversion of watersinto the East Poplar River,particularly if such a diversion would involve an inter-basin transfer of wators. - 213 -

APPENDIX "B"

DIRECTIVE TOTHE INTERNATIONAL POPLAR RIVER WATER QUALITY BOARD

On September 28, 1977,the International Joint Commission establishedthe International Poplar River Water QualityBoard to undertakethe technic31 investigation and to advisethe Commission on all matters which it mustconsider in reporting to the two Governments.The following Direztive to theBoard was issued 011 September 30, 1977:

1. TheGovernments of theUnited States andCanada have forwarded theattached Reference, dated August 2, 1977, to theComnission forexamination and report 2ursuant to Article IX of the Boundary Waters Treaty of 1909.

2. TheCommission established the International Poplar River Nater Quality Board on September 28, 1977, to undectake,through appropriate governmental or otheragencies in the United States andCanada, the necessary investigations and studies and to advisethe Commission on all matterswhich it mustconsider in making its reports to Governmentsunder the Attached Reference.

3. The Board shall I?xalnine intoand report ]upon the water quality of thePoplar River, including the transboundary water qual-ity implications of a 600-megawattthermal power station of tl;e SaskatcheanPower Corporation (SPC) an3 its ancillary facilities,including coal mining, at a site nearCoronach, Saskatchewan.The analysis of water qualityand its implications shall. includechemical, physical, biological, economicand social factors.In this regard the Board shall examineinto and report upon the Eol.lowingmatters regarding the Poplar River Basii1: - 214 -

(1) The present state of water qualityincluding fluctuations thereof, with particular emphasis on.the waters of the East Poplar River. (2) The f3ctors, both naturaland man-made, affecting existing water quality,and their e€fectson water uses. (3) The nature,'Location and significance of fisheriesand wildlifedependent on the waters of t!le Poplar River. (4) The nat,Jreand location of existingand reasonably. foreseeable water uses. (5) The eEfects onpresent water quality and consequent effects on the usesidentified in paragraphs (3) and (I) ,abwe,which would result from the following,both separatelyand cumulatively: (a) changesin the flow regime of the Poplar River, if apportionment of the waters of the Poplar River is made 8s recommendedby the International Souris-RedRivers Engineering Board's Poplar River Task Force in its Report of February 27, 1976, or as theComnission may otherwise , 3,) recommend; (5) the thermal power station of the SPC and ancillary facilities, including coal mining; (c) implementation of other reasonably foreseeable developmentsin either country. (6) Significanttransboundary impacts of the SPC's thermal power stationand ancillary facilities, including coal mining,and of reasonably foreseeable developmentsin eithercountry on the water qualityand water levelin the surroundingaqui€ers. (7) Such other matters as the Commission may indicate to the Board during the course of the study. - 215 -

4. The Board shall also advisethe Commission as to measures which could be taken to avoid or relieveany adverse transboundary effectsin the Basin, identiEied in sub-paragraphs (5) and (6) of paragraph 3, aboveand shall indicate the approximate costs :>E such measures. Inthis regard, if the Board concludes that the flows underthe recommended apportionment of the waters of thePoplar River may causesuch adverse effects, it shall propose, to theextent possible, measureswhich would avgid or relievesuch effects.

6. TheBoard shall prepare andsubmit €or Commissionapproval by November 1, 1977, a plan of study for theinvestigations that it proposes to undertake,and a schedule of estimated time and cost:s involvedin the completion of thenecessary phases of the study,including the subrnission to theComnission of interim reports as appropriateas well as a final report. The Governmentshave asked the Commission €or cost projectionsfor thestudies as early as practicable. Inpreparing its plan of study,the Board should be guidedby the following considerations: (a) The Board shall act as a unitarybody, carrying out its investigationsjointly in both countries as a coordinated andintegrated effort, and (b) provisionshould be made, where appropriate, forpublic informationand participation throughout the course of the study. - 216 -

7.Upon receipt of thestudy plan, the Commission will meet with the Board to discuss same and the Board shall carryout the programin accordance with the approvedplan of study. ~f it appears to the Board at any time in the course of its investigationsand studies that theprograms should be modiEied, it shall so advisethe Commission and request instructions.

8. The Board shall submit its finaireport and appendices, if any, and the necessaryquantity for public distribution, to the Commission no later than September 1, 1978.

9. Iq the c(>llduct (J€ its investiyation and in the preparation of its report or reports, the Board shall make use of information andtechnical data heretoforeavailable, or which may become availableduring the course of the investig?tion.The Board's attention is specificallydrawn to the report of the InternationalSouris-Red Rivers Engineering Board entitled "JointStudies for Flow Apportionment - Poplar RiverBasin in Saskatchewanand Montana", d2ted February 27, 1976, environmentalstudies undertaken or proposed bythe Saskatchewan Power Corporationand Governments of Saskatchewanand Canada, and the environmental studies beingundertaken by the State of Montanaand the United States Government. The Board should also draw upon the informationdeveloped through the international Water qualitymonitoring network in the Poplar RiverBasin which has been established by the Canadianand United States Governments.

10. The Board will. consi:;t oE a United States Sectionand a Canadian Section, each havingfour members. The Commission will appoint one member of each Section to be Chairman of that Section. At the request of any member, the Commission may approve ip each case analternate member to act in the place and stead of such member whenever the said member, forany exceptional reason, is notavailable to act as a member of theBoard. - 217 -

11. Members of the Board, and its committees and working groups, whether or not employed by departments or agencies of Gov?rnment, are not representatives of their employers. They serve in a personal and professional capacity under the direction of the Commission, and their employers 31: superior officers ,3re not committed in any way by the actions of the individual members of the Board.

12. The Chairmen of the two Sections shall. be joint Chairmen of the Board and shall be responsible for maintaining proper liaison between the Board and the Commission and between their respeztive Sections of the Board and the corresponding Sections of the Commission.

13. Each Chairman shall ensure that the other members of his Section of the Board are informed of all instructions, inquiries and authorizations received from the Commission; also of activities undertaken by or on behalf of the Board, progress made and any developments aEfscting such progress.

14. A Chairman, after consulting the other members of his Section oE the Board, may appoint a Secretary of that Section and a Public Information Officer of that Section. Under the general supervision of the Chairman, these individuals c,haI.l carry out such duties as are assigned to them by the Section.

15. The Board may establish such committees and working groups as may be required to discharge its responsibilities effectively and may enlist the cooperation of federal, provincial or state departments or agencies or others who could contribute in the United States and Canada. The duties and composition of any such committees shall be subject to prior approval by the Commission. The Board shall consider and adivse the Commission whether it would be desirable to appoint a coordinator to assist - 218 -

the Board in its investigation in view of the severe time, .,-~ constraints imposed on the study. Board and Committee me.rqb,ers 1. ' ,. :it will make their own arrangements for reimbursement of necessary I I. , expenditures for travel.

16. The Board shall maintain liaison with the International Souris-Red Rivers Engineering Board so that each may be aware of any activities of the other which may be useful .to-it or mqy have a bearing on its activities.

17. The Chairmen shall. keep the Commission currently informed of the Board's plans and progress and of any developments, actual or anticipated, which are likely to impede, delay or otherwise affect the carrying out of the Board's responsibilities.

18. The Chairmen shaLL submit, at least semi-annually and more often if necessary reports to the Commission describing the progress that has Seen made and any problems that have arisen to the investigation. All such reports sh311 be sent to the Secretaries of the Commission. Regular semi-annual reports should be submitted at least 30 days prior to the Commission's A?ril and October meetings.

19. If, in the opinion of the Board, there is a lack of clarity or precision in any instruction, directive or authorization received from the Commission, the matter shall be referred promptly to the Commission for appropriate action.

20. Documents, Letters, memoranda and communications of every kind in the official records of the Cornmission are privileged and become available for public information only after release by the Commission. The Commission considers all documents in the official records of the Board or of any of its committees to be similarly privileged. Accordingly all such documents shall be - 219 -

so identified and maintained in separate files. They shall become available for public information onlyafter Commission approval.

21. ‘In its dealings with the public and news media, the Board shall observe the principles of the attached documents on public relations policy dated 27 July 1973 and 20 September 1974 of the Commission and supplemented by the provisions of the study plan of the Board when approved by the Commission. - 220 -

Membership of the International PoplarRiver Water Quality Board

When the International PoplarRiver Water Quality Board suhitted its Report to the Commission the membership Df the Boardwas as follows:

United States Section Canadian Section

Dr. Robert C. Averett, Water Resources Dr.Robert K. Lane,Environmental Division, U.S. Geological Survey, Management Service,kvironment Canada, Max Dodson, U.S. Envircnmental Dr. F. Mervyn Atton, Saskatchewan Protection Agency Department of Tourismand Natural Resources Gary Fr i tz, Montana Department of Donald H. Lennox, National Natural Resources and Conservation Hydrological Research Institute, Environment Canada Dr.Abraham A. Horpestad, Montana Murray H. Prescott , Saskatchewan Department of Health and Department of the Environment Envircnmental Sciences Ernest H.G. Cornford, !%viromenta1 Management Service, Environment Canada, FormerBoard Members

Robert H. Hagen, U.S. EnvironmentalRichard H. Millest, rnvironment A gency, Canada,Protection Agency, Orrin Ferris, EJlontanaDepartment of Natural Resources and Conservation Gary E. Parker, U.S. kvironmenta'i Protect ion Agency, - 221 -

Membership of the Technical- Camnittees

When the Wardsubmitted its Report, khe Committees consisted of the follming members:

L

United States Section CanadianSection -__"- "" Dr. Abraham A. Horpestad, Montana Ken W. Reid, Ehvironmental Management Department of Health and Service,mvironment Canada, ~v.ironmental Sciences, Dr. 8Julos B. Cohen, U.S. Environmental. Roger A. McDonald, Saskatchewan Protection Agency Department of theEnvironment Dr. James I,. Thomas, U.S. Bureauof Dr. Simon H. Whitlm, Environmental Reclamation Management Service, Environment Canada

Groundwater Quantity and Quality Cmittee ~- "

Dr. Robert C. Avere tt, Water Resources Donald 13. Lennox, National Division, U.S. Geological Survey, Hydrological Resarch Institute, Environment Canada, Gerald L. Feder , Water Resources Gerald E. Gr isak, Hydrolog1 Divis ion, U. S . ralog ical. Survey ResearchBranch, Ehvironment Canada Marvin R. Miller, Montana Bureau of T.W. Rey, SaskatchewanDepartment Minesand Geology of the Environment* Q. James Taylor, Water Resources Dr. A. Schneider , Saskatchewan Divis ion, U. S. Geologocial. Survey Research Council S. Stan K. Weyer*

."i3iological Resources- Comi ttee

Donald L. Tennant, U.S. Fish and John S. Loch, Fisheries andMarine Wildlife Service, Service,Department of Fisheries and Oceans, Dr. Loren Bahls, Water Quality Bureau, Hugh Hunt, Saskatchewan Department Montana Department of Health and of Tburism and Natural. Resources EnvircnmentalSciences Loys Parrish, U.S. kvironmental Al Kristofferson, Fisheries and Protection Agency MarineService, Department of Fisheries andOceans James E. Posewitz, Montana Department Dr. William Sawchyn, Saskatchewan of Fish and Game Research Council. - 222 -

Usesand Water Quality Objectives Committee

United States Section Canadian Section

Dr. D. Scott Brown,Montana Department S.W. Reeder,Environmental Management of Natural Resources and Conservation Service, Eenvironmental.Canada

Robert J. Burm, U.S. Environmental Dr. Doug R. Cameron, Swift Current Protection Agency Agricultural Research Station, Agriculture Canada Dr.Abraham A. Horpestad, Montana Don A. Fast, SaskatchewanDepartment Departmentof Health and of the Environment Envi rcnmental Sciences Dr. James R. Sims, Plant and Soil 30n T. Waite , SaskatchewanDepartment Science Departnent, Montana State of the Environment University MikeWatson, Yorrison-Maicrle, Inc.

.-___Plant, Mine and Reservoir Operations -" Committee Lee R. Rice, U.S. Bureau of ;dines, D. Wayne Draper,Environmental Department of the Interior, ProtectionService, Environment Canada, Mike Bishop, MontanaDepartment of R. Wayne Nordquist, Saskatchewan State Lands* mer Corporation Dr.Gary E. Glass, Znvirmental Cliff L. Potter, Saskatchewan Research Laboratory, U. S . Department of the Environment Environmental Protection Agency Dan B. Kimball, U.S. Environmzntal Gary Sergy, Environmental Protectiori Protection Agency Service, EnvironmentCanada David M. StilLer, Montana Department of State Lands*

*These individuals served on the Cmittees but were not members at the time the Board Report was submitted. - 223 -

APPENDIX "E"

Participating Organizations

Valuable and cooperative assistance was provided by the following organizations:

United Stat?s Environmental Protection Agency United Stzites Bureau of Reclamation United States Geological Survey United States Fish and Vildlife Service United States Bureau of Mines Montana Department of Natural Resources and Conservation Montana Department of Health and Environmental Sciences Montana Bureau of Mines and Geology Montana Department of Fish and Game Montana Department of State Lands Montana State University Morrison-Maierle, Inc.

In Canada

Environment Canada Department of Fisheries and Oceans Agriculture Canada Saskatchewan Department of Tourism and Natural Resources Saskatchewan Department of the Environment Saskatchewan Research Council Saskatchewan Power Corporation - 224 -

APPENDIX "'F''

On January27, 1978, the International Joint Commission sentthe following letter to theGovernments of Canadaand'the Un i ted States:

Pursuant to yourReference of August 2, 197.7,tne InternationalJoint Commission established the International Poplar Iiiver Water QualityBoard on September 30, 1977.The Commission met withthe co-chairmen of the Board onJanuary 19, 1978, to receive andapprove a Pl3n of Study,and to discuss its request to theBoard to consider, *as a matter ofpriority, the effects of continued projectdevelopment on the Board's ability to conduct its study.

TheCommission was informedthat, in spite of concerted effortsby the Board to obtain all water qualitydat.3 in the possessionof the Saskatchewan Power Corporation (SPC), it has been unable to do so. By let,ter to the SPC, dated November 3, 1977,the Board requested copies ofthe reports required bythe Province of Saskatchewan on theenvironmental impacts €or the Poplar River power plant,near Coronach, Saskatchewan. To datethe Board has received onlythe summary report. TheBoard has beeninformed that alL of theappendices, except theappendix on water qualityand wild.Life, havebeen forwarded to the Board. Theyhave nat yet been received. The Boardhas also beenadvised by the SPC thatthe critical appendixon water qualityand wildlife would not be available untiL theend o€ Februarysince the Government of SaskatchewanDepartment ofEnvironment has asked for a more complete study of the environmental irnpaet andthe necessary remedial measures.

Theinformation contained in theappendix on water quality andwildlife is vital to the Board's investigationsince it representsthe baseline data which is to serve as thestarting point of the Board's study. If the information is not made available to the Board, it will be necessary to acquire the raw datafrom SPC and then make a time consumingindependent assessment. Moreover, if the raw data now collected itsel€ is inadequate, it will benecessary to obtainadditional data. Thus,continued work onthe Poplar River Project, particularlythe associated coal-mining operation, may materiallyand irrevocably alter conditionsin the study area before the Board hasbeen able to determinewhether or notadequate baselinedata is available.Therefore the Board at this time in unable to advisethe Commission if continued project development wouldsubstantially interfere with its studyand whether completion of theBoard's investigation may be undulydelayed. Consequently, the Commission now recommends that all construction, excavation and de-watering on the Poplar River project, including the associated coal-mining operations be stopped until the Board has received the information it requested from the SPC, and until the Board has had an opportunity to assess the information.

The Commission has also been advised by its International Poplar River Water Quality Board that, due to the magnitude of the study required and the delays that have already occurred, its report to the Commission will now be delayed by four months. This assumes that no further delays in receiving cri.tica1information will. be encountered. Thus, the Commission's own report to the Governments of Canada and the United States will iI0t be submitted earlier than April , 1979. - 226 -

On February 22, 1978,the Governments of Canadaand the United States sentthe following letter to theInternational Joint Commission:

This letter constitutesthe response of theGovernments oE Canadaand the United States to theComnission's letter of January 27 pursuant to theGovernments' Reference to theCommission ofAugust 2, 1977,concerning water quality aspects of the Poplar River project.

TheGovernment:3 have consulted concerning the Commission's letter, includingthe request of theCommission's International Poplar River Water QualityBoard to theSaskatchewan Power Corporation €or certaininformation regarding the water qual-ity aspects ofthe project.

TheGovernments understand that thenine appendices which theCornmission's letter noteshad been enroute to theBoard Erom the SPC were receivedon February 2, 1978.The Governments also understandthat the final draft version of theappendix on water qualityand aguatic life, whichthe Commission had understood would notbe avsilahle until the end of February, was made available to the SPC by it.; consultantsJanuary 31 andreceived by the Commission onFebruary 5, 1978. It is theGovernments' understanding that the i3oard now hasin its possession all ofthe material which it had requestedfrom the Saskatchewan Power Corporation.

TheGovernments note that the Board intends to assess the adequacy: of thebase-line data av3ilable for its study,which includesexisting data andinformation additional to the reports recentlyprovided by the SPC. TheGovernments request the Commission to report to Governmentsthe results of thatevaluation as quickly as possible, inany case no later thanMarch 15, 1978.

The CanadianGovernment has beenadvised by the SaskatchewanPower Corporation that the current status of site activity is as follows: - Dewatering is beingcarried out at theapproximate rate of 5 cfs,the rate at whichdewatering has been carried out for severalyears.

- Constructionactivities are primarilydirected toward the plantstructure; with only limited externalactivity. - Overburdenremoval andmining activity has not yet commencedand will notcommence for some months.

- Mine test pit 2ctivityhas been completed. - 227 -

- The reservoir is currently one-third full at approximately the same level as one year ago; no filling activity except from dewatering is being carried out or is planned other than the retention of spriilg run-offs.

The Government of Canada has assured the Government of the United States that no alteration in the activities described above is planned or will take place, prior to receipt of the Commission's report requested by March 15. The Governments have no reason to believe that the data and information now av3ilable to the Board for its water quality study wilL prove to be less than adequate. Yowever, should the Commission have concerns as a result of the Board's assessment regarding its capacity to carry out its study under the Terms of the Reference, it is requested to communicate these to Governments in speciEic terms. I? this case, the Governments will cooperate to ensure that construction or other activities will not interfere with the timely colLection of data consistent with the Commission's responsibilities under the Reference. It is the view of Governments that maintenance oE the status quo for the limited period until the Commission's report of March 15 will not prejudice subsequent collection of additional base-line data. The Governments are concerned about the possible delay in the completion of the Reference mentioned in the Commission's January 27 letter. The Governments would appreciate receiving a full report on the Commission's conclusions and recommendations as expeditiously as practicable, if at all possible by December 1, L978 as originally requested in the Reference. In the event a full report is not possible by December 1, the Governments request a report at that time, including the Commission's substantive findings and recommendations a!; of that date. - 228 -

On March 13, 1975, theInternational Poplar River..Waker Quality Board sentthe following letter to the International Joint Commission:

Meeting of the Board atCalgary, March 7/8, 1978. - " .____"_ As requested by the IJC members at the March 3rdmeeting in Montreal, we arehereby reporting on severalissues addressed by the Board at ourrecellt Calgary meeting, whichwere of particular interestto the Commissioners. Will you pleasetransmit this informatimaccordingly.

1. The availability and adequacy of datareqllired from Saskatchewan Power Corporation -""- """_ __ - - At theBoston meeting, %he PR WQB i.ndicated that .:7e:Lays in receivingcertain data from SPC wereimpeding the work of the Board. Tnesc? dataare now in hand.Although datagaps still. exist, it is expectedthat these can be acquired within the revisedplanning schedule of theBoard. The review of adequacy has primarilyfocussed on completion of thedata base method to carryout the assignment to the Board. If furtherreviews indicateconcerns about binational compatibility of sampling proceduresor accuracy of thedata, these will be communicated to SPC.

2. Will SPC operationsprejudice the acquisition of baseline data still to be acquired? "" "" -" __ ~ SPC construction plans asunderstood by the Board at this time, contain no provisions which will prejudicethe collection oE basicdata, where gapshave been identified.Certain data gaps, however, relateto possible effects of itemsto be constructed; in particular,uncertainties as tothe degree of seepage from ashlagoons and the waste retention pond. These items, as well as a concernrelated to the effects of thedevelopment on the dissolved oxygen conditions of poolsdownstream, have all been Communicated to SPC and we wi.LL i.ndicateto SPC, aswell as to the IJC, any firmbases for alarm on thesematters, as they may developthrough analyses of data.

3. How have delays in obtaining"__ data__ affected the Board's schedule? These delays,as well as internal. slippage, andamore realistic evaluationof report preparation, result in thesetting of May 1, 1979, as ourrevised proposed date €or submission of our finalreport to the IJC. Details will appear in ourforthcoming progressreport. - 229 -

4. Meetina with SPC at our Caluarv meetina Our meeting with SPC was very cordial. Mr. Ursel, the General Manager, was informed of our current satisfaction as to the cooperation being provided by SPC. We discussed ways of continuing and improving our interactions. At a follow-up news conEerence, attended by the Globe and Mail, and CBC TV, the co-chairmen and Mr. Ursel provided background information and answered questions. The Globe and Mail account was inaccurate, though not very seriously. Mr. Ursel also provided a solo interview with CBC TV, at CBC's request. - 230 -

On April 10, 1978,the International Joint Commission sent

Y, I , thefollowing letter to the Governments of Canada and the,United. . , , .. States: 1 ,.

By letterdated January 27, 1978, the Commission. advised Governments thatcertain data from Saskatchewan Power Corporation

(SPC) were unavailable and thatcontinued work on thePoplar River ' ', Projectcould materially and irrevocablyalter conditions in the-: study area beEore the Boar'dwould have an opportunityto assess the adequacy of thesebase-l.ine data. By letter of responsedated February 22, '1978, Governmentsnoted thesubsequent receipt of certaindata by the Board from SPC and reequestedthe Commission to reportthe results of its Board'sassessment of the adequacy of the base-linedata av3ilable for its study.

The Board hasadvised the Commission that it hasreceived thedata requested from SPC; thatthese data are generally adequate for it toproceed to evaluate present conditions and base-line conditions where they st,i11 existor can be simulated;that certain datagaps exist, but ik is expectdthat these can be filled within therevised planning schedule of the Board.

The Board has alsoadvised the Commission thatthe SPC constructionplans, as understood by the Board at this time,contain no provisions which will prejudicethe collection of data where gaps havebeen identified. However, certaindata gaps relate to possible effects of itemsto be constructed, and in particular,uncertainties asto the degree of seepage from ashlagoons and thewaste retention pond. The Board hascommunicated its concernregarding this uncertaintyto the Saskatchewan Power Corporation. The Commission is of theopinion that such works shouldnot be undertaken until adequatedata havebeen provided. The Board also hasadvised that whilecertain data concerning the dissolved oxygen content of downstream pools in thePoplar River and theeffects of the mine-dewateringprogram cannot be assessedat this time,these data will be acquiredat an appropriatetime during the coming months.

The Commission is unable at this time toadvise Governments of otherspecific concerns which might affectthe Board's capacity tocarry out its studies. However, shouldthe Board be unable to completeda.ta gaps related to ongoing works, and tothose works yet to be undertaken,the Commission shall communicatesuch specific concernspromptly to Governments.

The Commission is concernedthat the filling of the reservoircould result in waterquality changes, some of which may be adverse. The datarequired to determine such changes,however, arenot yet available. The Commission hasinstructed the Board to - 231 - advise it upon determining any adverse water quality changes that would require modification in SPC's construction program. Upon receipt of such advice,the Commission will immediately inform the Governments.

The Commission concludes, based on its Board report, that continued work on the Poplar River Projezt should not materially and irrevocably alter conditions in the study area beyond that which may have alresdy occurred before theBoard will have an opportunity to assess the adequacy of the available data, and subject to the above safeguards, is satisfied that work on the project may proceed. - 232 -

APPENDIX "G"

Persons Presenting Briefs or Testimony at IJC Public Hearincrs

November 2. 1977 at Scobev, Montana Jim Schulenberg €or Montana Senator John Melcher Clancy Rich €or Congressman Ron Marlenee, U.S. House of Representatives Ted Schwinden, Lieutenant-Governor, State of Montana Grant Mitchell, Deputy Yinister,Saskatchewan Department of the Environnen t Congressman Max Qaucus, U.S. House of Representatives Ed Smith, Montana St*3te Senator, District No. l Art Lund, Montana State House of Representatives, District No. 2 Dennis G. Nathe, Montana State House of Representatives, District No. 1 Morris Billihus for Daniels County Board of Commissioners, Montana Alfred Kaschube for Roosevelt County Commissioners, Montana Curt Holje for Sheridan County Commissioners, Montana Norman Hollow, Tribal C'hairman of the Fort Peck Assiniboine and Sioux Tribes, Montana Dr. Kenneth C. Lee, Scobey, Montana Orville Odegard for Whitetail Sports Club, Montana Glen Jacobsen €or Econoinic Development Association of Eastern Montana Lee Humbert, Scobey, Montana Robert Nilson, for Daniels County 4-H Council, Montana Bill Cromwell for Daniels County Planning Board, Flaxville, Montana Caleb Shields, National Congress of American Indians Dr. Robert Bell, Culbertson, Montana Melvin Schow, Senior Citizens, Scobey, Montana Terry Kincannon, Scobey, Montana Lowell Burgett, Scobey, Montana Clark Tousley, Mayor, Scobey,Montana J. Perry Wolfe, Scobey, Montana Norman Nelson, for Northeast Montana Land and Mineral Owners Association, Westby, Montana Bill Tande for Daniels County Livestock Association, Montana Robert Schneekloth for Three Corners Boundary Association and the Northern Plains Resource Council, Flaxville,Montana Lorraine Pedersen €or Big Muddy Cow Belles, Westby,Montana Barry Handy for Middle Fork Irrigators, Scobey, Montana Dr. Wayne Wilson, Daniels CountyFarm Bureau, Montana Mrs. Arlo Anderson for Daniels County Branded Cow Belles, Scobey, Montana Rick Anderson for Middle and East Fork Irrigators, Scobey, Montana Milton Shipstead, Farmers Union, Scobey, Montana Boyd Tymofichuk, Daniels County Soils Conservation District, Montana - 233 -

Merle D. Fitz, M.D., Daniels County Health Department, Scobey, Montana Scobey Commercial Club, Montana Board of Trustees, Montana School District No. 1, Scobey, Montana

November 3, 1977 at Regina Saskatchewan """ _"____ R. Wayne Nordquist for Saskatchewan Power Corporation Grant Mitchell, Deputy Minister,Saskatchewan Department of the Environment

SeDtember 10, 1979 at Scobev, Montana Jim Molloy for Montana Senator Max Baucus Alan Felt for Congressman Marlenee, Districtof Montana Ted Schwinden, Lieutenant-Governor, State Df Montana Ted Bowerman, Minister of the Environment, for Government of Saskatchewan John R. Messer, Minister in charge of the Saskatchewan Power Corporation and Minister of Mineral Resources Mickel Lund f.3r Art Lund, Montana State Representative, DistrictNo. 2 Ed Smith, Montana State Senator Dennis Nathe, Montana House of Represcntatives David Johnson, for Fort Peck Assiniboine and Sioux Tribes, Montana Lionel Bergstrom, Chairman, Board of Inquiry into Poplar and Nipiwan Projects, Saskatchewan Bill Tande for Daniels County Commissioners, Montana Bill Cromwell for Daniels County Planning Board, Montana Merle D. Fitz, M.D., Daniels County and Scobey City Health Officer, Montana Sid Friedland for U.S. Department of State Dr. J.D. Rhoades, U.S. Salinity Laboratory, Riverside, California Carroll Ferestad, Scobey, Montana Mrs. Scheekloth for Mrs. Charles Humbert, Scobey, Montana Lee Humbert, Scobey, Montana Ron Stoneberg, Redstone, Montana Ralph Susag, West Fork Poplar River, Montana Jack Pittenger, East Fork Poplar River, Montana Dr. Kenneth Lee, D.V.M., Scobey, Montana Dr. James R. Sims, Professor of Soils Science, Montana State University Eric Hansen, alternatemember on Uses and Water Quality Objectives Committee, Montana Milton Gunderson, for Scobey Commercial Club, Montana Bill Tande for Daniels County Livestock Association, Montana Barry Handy for Middle Fork members of the Daniels County Water Users and Irrigators Association, Montana Boyd Tymofichuk for Morris Billehus, Economic Devlopment Association of Eastern Montana - 234 -

September 11, 1979 at Coronach, Saskatchewan ""_l_____""""- Bob Schneekloth for Three Corners Boundary Association; for Orville Odegard and Whitetail Sports Club; for Elmer Halverson and Daniels County Livestock Association; for Ken Hellickson and Daniels County Water Users and Irrigators Association Mrs. Marlys Farver, Daniels County WIFE, Scobey,Montana Dennis Unsworth, Radio Station KCGM-FM, Scobey, Montana Ted Bowerman, Minister of the Environment, €or the Government of Saskatchewan John Messer, Minister in charge of the Saskatchewan Power Corporation and Minister of Mineral Resources Allan Engel, nember of the Saskatchewan Provincial Legislative Assembly for Assiniboia Anne Park, Canadian Department of External Affairs for Flora MacDonald, Secrc3tary of State for External Affairs Rev. Randall Yackenzie, United Church of Canada, Coronach, Saskatchewan Nartin Nowakowski, for Local 2067 International Brotherhood of Electrical Workers, Saskatchewan Glen Peterson, Eastevan Chamber of Commerce, Saskatchewan Ross Strachan, Coronach CommunityChamber of Commerce, Saskatchewan Harold Sigglekow, Mayor of Coronach, Saskatchewan Fred Ursel, General Manager, SaskatchewanPower Corporation; Dr. Stewart Behie, Montreal Engineering Company; Tom Prickett, Camp Dresser and McKee, €or Saskatchewan Power Corporation Grant Yitchell, Deputy Minister,Saskatchewan Department of the Environment

October" 15, 1979 at Regina, Saskatchewan R. Wayne Nordquist for Saskatchewan Power Corporation Harold Sigglekow, Mayor of Coronach, Saskatchewan Ted Bowerman, Minister of the Environment, for the Government of Saskatchewan Dennis J. Unsworth for Three Corners Boundary Association, Scobey, Montana Grant Mitchell, Deputy Minister, Saskatchewan Departmentof the Environment

October 16, 1979 at Scobey, Montana " " Bob Cummings, Scobey Chapter of the Future Farmers of America, Montana Dr. Kenneth Lee, D.V.N., Middle Fork Poplar River below confluence, Montana Cherie Danelson, student, Scobey,Montana Jill Farver, Happy Valley 4-H Club, Scobey, Montana Gerry Farver, Earmer-rancher below confluence, East and Middle Forks, Montana - 235 -

Dale Chabot, Scobey, Montana Ken Hellickson, Three CornersBoundary Association Montana Ron Stoneberg, Redstone, Montana Boyd Tymofichuk, Scobey, Montana Marlys Farver, Daniels CountyWIFE, Scobey, Montana Barry Handey, Middle Fork Poplar River, Montana Lowell Burgett, East Fork Poplar River, Montana Mrs. Humbert, Montana Dr. .James R. Sims, professor of Soil Science, Montana State University Milton Gundzrson, Flaxville, Montana Carroll. Ferestad, Middle Fork Poplar River, Montana Bob Schneekloth, Three Corners Bound.ary Association, Flaxville, Montana Terry Danelson, Middle Fork Poplar River, Montana Mrs. Eva Schow, Montana Mrs. Donna Pratt, WIFE, Montana Daryl Fiadager, West Fork Poplar River, Montana Ralph Sasag , Scobey , Montana Gerry Farver tor Delmer Safty and Whitetail Sports Club, Montana Lee Humbert, Yiddle Fork Poplar River, Montana

October 17, 1979 at Scobey, Montana ~_.__~. -- “__”- Mr. Barrett for Montana State Senator John Melcher Merle D. Fitz, M.D., Qaniels County and City of Scobey Health Officer, Montana Milton Shipstead, Peerless, Yontana Jack Pitinger, East Fork Poplar River, Montana Miss Zelpha Danelson, Dahiels County WIFE, Mont3na Boyd TymoEichuk for Mr. Bowler, Scobey Commercial Club, Montana Dr. ,James R. Sims representing Congressman Kent Xance, 19th District, State of Texas Ted Schwinden, Lieutenant-Governor, State of Montana John Totton, Councilof the Rural Municipality of Hart Butte Number 11, Saskatchewan Ed Smith, Montana State SenatQr, District No. 1 Art Lund, Montana State House of Representatives, District No. 2 Dennis Nathe, Montana State Houseof Representatives, District No. 1 Bill ‘rande, Daniels County Commission, Yontana Bill Cromwell,, Daniels County Planning Board, Montana David &Johnson and for Norman Hollow, Fort Peck Sioux and Assiniboine Tribes, Montana Gerry Farver, Scobey, Montana Grant Mitchell., Deputy Minister, Saskatchewan Departmentof the Environment Dr. J.D. Rhoades, TJ.S. Salinity Laboratory, Riverside, California Dr. Doug Cameron, Research Scientist, Swift Current Agricultural Station, Saskatchewan - 236 -

APPENDIX "H"

."___"___"Selected BoronReferences

Adams, F.S., Cole Jr., and L.B. Massie. 1973.Element constitution Df selectedaquatic vascular plants from Pennsylvania:submersed and floating leaved species androoted emergent species. Environ.Poll. 5:117-147

Allan, R.J., and D.J. Richards.1973. Effect of a therm'al generatingstation ondissolved slDlidsand heavy metals in a prairie reservoir. Ynvironment Canada,Scient. Ser. NO. 93

Bingham, F.T., and A.L. Page. 1971. Specificcharacter of boron absorption by an amorphous soil. Soil Sei. SOC. Amer. Proc. 353892-893

Bingham,F.T., A.W. Marsh, R. Branson, R. Mahler,and G. Ferry. 1972.Reclamation of .Salt-AffectedYigh Boron Soils in Western KernCounty. Nilgardid. 41: L95-210

Bowen, J,E. 1977.The fine art of usingenough but not too much boron. Crops and Soils Magazine 12-14

Boyd, C.E. 1969. BoronAccumulation by NativeAlgae. Amer. MidL. Nat. 84:565-567

Boyd, C.E., and J.Y. Lawrence.1967. The mineral composition of severalfreshwater algae. Proc. of theTwentieth AnnuaL Conference. S.E. Assoc. of Game andFish Commissioners 413-424

Boyd, C.E., and W.W. Walley.1972. Studies of thebiogeochemistry ofboron, 1, concentrationsin surface waters, rainfall. and aquatic plants. Amer. Midl. Natur. 88:l-14

Brown, J.C., and J.H. Graham.1978. Requirements and tolerance to 2lementsby alfalfa. Agron. J. 70:367-373

Calder, F.W., and W.M. Langi'lle.1963. Trace element effects on oats andalfalfa grown on three soils. Can. J. Plant Sci. 43:482-489

Carriber, N.E.,and P.L. Brezonik.1978. Sources, levels, and reactions of boronin Florida waters. J. Environ.Qual. 7:516-522

Chauhan, R.P.S., and S.L. Powar. 1978.Tolerance of wheat and pea to boron inirrigation water. Plantand Soil 50:145-149 - 237 -

Chu, T-Y. .Jr., and R.J. Ruave.1978. Characterization and reuse ofash pond efluents in coal-fired power plants. ,J. Water Poll. Cont. Fed. pp. 2494-2508

Cox, J.A., G.L. Landquist, A. Przyjazny,and C.D. Schmulbach. 1978.Leaching of boronfrom coal ash.Envir. Sci. and Tech. 12:722-723

Dionne, J.L., et A.R. Pesant.1978. Effets des doses de bore, desregimes hydriques et du pH des sols sur les rendements de la luzerne et du 'Lotier et sur i'assimilabilite du bore. Can. J. Soil Sci. 58:369-379

Eaton, F.M.. 1944.Deficiency, toxicity and accumulation of boronin plants. J. Agr. Res. 69:237-277

Eaton, F.M., and L.V. Wilcox. 1939.The behaviour of boron in soils. USDA Tech.Bull No. 696,57 pp.

Fox, !?..H. 1967.The effect of calcium and pH onboron uptake fromhigh concentratiolx of boron by cotton and alfalfa. Soil Sci.106:435-439

Furr, A.K., T.F. Parkinson, W.H. Gutenmann, I.S. Pakkala,and D.J. Lish.1978. Elemental content of vegetables,grains, and foragesfield-grown on flyash anended soil-. J. Agric.Food Chem. 26: 357-359

Gerloff, G.C.. 1968. The comparativeboron nutrition of several greenand blue-green algae. Physiol, Plant 21:369-377

Gough, L.P., H.T. Shacklette,and A.A. Case. 1979.Element concentrationstoxic to plants,animals and man. USGS Survey Bull. 1466, 80 pp.

Green, G.H., and H.J. Weeth.1977. Responses of heifers ingestingboron in water. J. Anim. Sci. 46:812-818

Green, G.H., Y.D. Lott, and H.J. Weeth.1373. Effects of boron-water on rats. J. Anim. Sci. 36:1203-1204

Gladney, E.S., L.E. Wangen, D.B. Curtis,and E.T. Jurney.1978. Observationson boron release fromcoal-fired power plants. Environ. Sci. Technol-.l-2:LO84-1085

Gupta, U.C. 1970.Boron requirement of alfalfa,red clover, brussclsprouts and cauliflower grown under greenhouse conditions.Soil Sci. 112:280-281 - 238 -

Gupta, U.C. 1971. Boron and molybdenum nutrition of wheat, barley and oats grown in Prince Edward Island soils. Can J. Soil Sci. 51: 415-422

Gupta, U.C. 1972. Effects of boron and lime on boron concentration and growth of forage legumes under greenhouse conditions. Comm. in Soil Sci. and Plant Anal. 3:355-365

Gupta, U.C. 1972. Interaction effects of boron and lime on barley. Soil Sci. SOC. of Amer. Proc. 36:332,334

Gupta, U.C. 1977. Effects of boron and limestone on cereal yields and on B and N concentratiDn of plant tissue. Plant and Soil 47:283-287

Gupta, TJ.C. and J.A. MacLeod. 1977. Influence of Calcium and Magnesium Sources on Boron Uptake and Yield of Alfalfa and Rutabagas as Related to Soil pH. Soil Sci., 124:279-284

Gupta, U.C., J.S. MacLeod, and J.D.E. Sterling. 1976. Effects of boron and nitrogen on grain yield and boron and nitrogen concentrations of barley and wheat. Soil Sci. SOC. Amer. 40:723-726

Gupta, U.C.,

Hadas, FI., and J. Gagin. 1972. Boron absorption by soils as influenced by potassium. Soil Sci. 113:189-133

Hatcher, J.T., and C.A. Bower. 1958. Equilibria and dynamics of boron adsorption by soils. Soil sci. 85:319-323

John, M.K., H.H. Chuah, and C.J. Van Laerhoven. 1977. Boron response and toxicity as affected by soil properties and rates of boron. Soil Sci. 124:34-38

Neary, D.G., G. Schneider, and D.P. White. 1975. Boron toxicity in red pine following municipal waste water irrigation. Soil Sci. SOC. Amer. Proc. 39:981-982

Peterson, L.A., and R.C. Newman. 1976. Irlfluence of soil pH on the availability of added boron. Soil Sci. SOC. Amer. 40:280-282

Plank, C.O., D.C. Martens, and D.L. Hallock. 1975. Effect of soil application of fly ash on chemicalcomposition and yield of corn ”(Zea -mays L.) and on chemical composition of displaced soil solutions. Plant and Soil 42:465-476

Prather, R.J. 1977. Sulfuric acid as an amendment for reclaiming sr3ils high in boron. Soil Sci. SOC. Amer. 41:1098-1100 - 239 -

Ryan, J.S. Miyamoto, and J.L. Stroehlein. 1977. Relation of solute and sorbed boron to the boron hazard in irrigation water. Plant and Soil 47:253-256

Scanlon, D.H., and J.C. Duggan. 1979. Growth and element uptake of woody plants on fly ash. Environ. Sci. Technol. 13:311-315

Schalscha, E.B., F.T. Bingham, G.G. Galindo, and H.P. Galvas. 1973. Boron adsorption by volcanic ash soils in Southern Chile 116: 70-76

Sheikh, K.H., and S. Khanum. 1976. Some studies of the quality of irrigation water and the germination and growth of wheat at diEferent concentrations of boron. Plant and Soil 45:565-576

Temple, P..7., and S.N. Linzon. 1976. Boron as a phytotoxic air pollutant. -7. Air Poll. Cont. I\ssoc. 26:498-499

Temple, P.J., S.N. Linzon, and M.L. Smith. 1978. Fluorine and boron effects on vegetation in the vicinity of a Eiberglass plant. Water, Air and Soil PolL. 10:163-174

Thompson, J.A.J., and J.C. Davis. 1976. Toxicity, uptake and survey studies of boron in the marine environment. $7. Int. Assoc. Water Poll. Res. 1_0:869-875

Waggott, A. 1969. An investigation of the potential problem of increasing boron concentrations in river and water courses. J. Int. Assoc. Water Poll. Res. 3:749-765

Wangen, L.E., and M.D. Williams. 1978. Elemental deposition downwind of a coal-fired power plant. Water, Air and Soil Poll. 10: 33-44

Wilcox, L.V. 1960. Boron injury to plants. TJSDA, Ag. Irlfo. Bull. No. 221, 7 pp. - 240 -

APPENDIX I"

Additional Computer Runs

Identification"___ Key for Computer" Scenarios

__ ~- ash lagoon aportiment rates seepage (l/s) to: scenario in ______level of water uses East Fork Cookson 1J.S. below - number effec:t Canada "_ reservoir "___"Reservoir 2A 1985 197 5 0 0 2B 2000 1975 0 0 7NM 1975 1975 0 2.5 9NM 2000 1985 0 2.5 l0NM 1975 1975 0 2.5 1. LNM 1985 1985 0 2.5 7M4 1975 1975 2 1 7M5 1975 1975 1 0.1 7M6 1975 1975 0.5 0.1 8M4 1985 1985 2 1. 8M5 1985 1985 L 0.1 8M6 1985 1985 0.5 0.1. SC8Mh 2.6 3.6

-k442 2.6 3.4 "5 42 2.2 2.6 -f:& 42 1.8

SEI' MEAN

3.1

-t:342 2.4 3.2 -"..J2. - 242 - - 243 - - 244 -

- 246 -

'A r3

z "? 3

(y: c) "

r r:

C 71

c -3 b" ln k 4 v-

r - 248 -

>- i C 5

z 3 I c Q c m - 249 -

7 c 3

3 3 - 250 -

Z 3 - 251 -

'3 -L

Z 3 z C a

'3 Z

c - 252 -

7 L Q J - 253 -

m +-P d 0 LL - 254 - - 255 -

J IT

LL 0 z 3

z

0 Y Y Q z 'U 0 m - 256 -

-I h

Z 3 -7 0 z

n 0 IJ

C z

0 n

- LSZ -

... - SSZ - - 259 -

7 L 3 z n v, c3 t if 0 lL cl) Z Y

z r: 3

c - 09z - m 0 m C C c P c rc' 7 < Q 0 r L -4 P

- 192 - C 3

- z9z - - 19z - - P92 - - 265 -

APPENDIX I'J"

International Law Association HelsinkiRules onthe USES OF THE WATERS OF INTERNATIONAL RIVERS*

CHAPTER 1

GENERAL

Article I

Thegeneral rules of international law as set forthin thesechapters are applicable to the use ofthe water of an internationaldrainage basin except as may beprovided otherwise by convention,agreement or bindingcustom among the basin States.

Article I1

An internationaldrainage basin is a geographical area extendingover two or more Statesdetermined by the watershed limits of thesystem of waters, includingsurface and underground waters, Elowinyinto a comnonterminus.

Article I11

A "basin State" is a state theterritory of whichincludes a portion of aninternational drainage basirl.

*TheseArticies were formallyadopted Aug. 20, 1966, bythe International Law Association (ILA) inHelsinki at its 52nd Conference. - 266 -

CHAPTER 2

EQUITABLE UTILIZATION OF THE WATERS OF AN INTERNATIONAL DRAINAGE BASIN

Article IV

Each basill State is entitled, within its territory, to a reasonable and equitable share in the beneficial use of the water of an international drainage basin.

Article V

(1) What i:; a reasonable and equitable share within the meaning of Article IV is to be determined in the light of all the relevant factors in each particular case.

Relevant fllctors which are to be considered include, but lixited to: the geography of the basin, including in particular the extent of the drainage area in the territory of each basin State; the hydrology of the basin, including in particular the contribution of water by each basin State; the climate affecting the basin; the past utiliz3tion of the waters of the basin, including in particular existing utilization; the economic and social needs of each basin State; the population dependent on the waters of the basin in each basin State; the comparative costs of alternative means of satisfying the economic and social needs of each basin State; the availability of other resources; the avoidance of unnecessary waste in the utilization of waters of the basin; - 267 -

the practicability of compensation to one or more of the co-basin States as a means of adjusting conflicts among uses; and the degree to which the needs of a basin State may be satisfied, without causing substantial injury to a co-basin State.

The weight to be given to each factor is to be determined by its importance in comparison with that of other relevant factors. 1'1 determining what is a reasonable and equitable share, all relevant factors are to be considered together and a conclusion reached on the basis of the whole.

Article VI

A use or category of use.? is not entitled to any inherent preference over any other use or category of uses.

Article VI1

A basin State may not be denied the present reasonable use of the waters of an international drainage basin to reserve for a co-basin State a future use of such waters.

Article VI11

1. An existing reasonable use may continue in operation unless the factors justifying its continuance are outweighed by other factors leading to the conclusion that it be modified or terminated so as to accommodate a competing incompatible use.

2. (a) A use that is in fact operational is deemed to have been an existing use from the time of the initiation of construction directly related to the use or, where such construction is not - 260 -

required, the undertaking of comparable acts of actual implementation. (b) Such a use continues to be an existing use until such time as it is discontinued with the intention that it be abandoned.

3. A use will not be deemed an existing use if at the time of becoming operational it is incompatible with an already existing reasonable use.