1995 ANNUAL REPORT

to the

GOVERNMENTS OF CANADA, UNITED STATES,

SASKATCHEWAN AND MONTANA ^^^ ^ocumms comrm

M VI 1997

il«ONTANA STATE LIBRARY '^^-J^^!Vo.?aV/C

by the

POPLAR RIVER

BILATERAL MONITORING COMMITTEE

Poplor

COVERING CALENDAR YEAR 1995

• %Bia

December 1996
Montana State Library

3 0864 1004 5767 3
1995 ANNUAL REPORT

to the

GOVERNMENTS OF CANADA, UNITED STATES,

SASKATCHEWAN, AND MONTANA

by the

POPLAR RIVER BILATERAL MONITORING COMMITTEE

COVERING CALENDAR YEAR 1995

December, 1996

Poplar River Bilateral Monitoring Committee

Dq)artnient of State Washington, D.C., United States

Governor's Office

State of Montana

Helena, Montana, United States

Department of External Affairs and International Trade Canada

Ottawa, Ontario, Canada

Saskatchewan Environment and

Resource Management

Regina, Saskatchewan, Canada

Ladies and Gentlemen:

Haein is tfie 15* Annual Report of the Poplar River Bilateral Monitoring Committee. This rq»rt

discusses the Committee activities of 1995 and presents the proposed schedule for 1996.

During 1995, the Poplar River Bilateral Monitoring Committee continued to fulfil the

responsibilities assigned by the governments under the Poplar River Cooperative Monitoring

Agreement dated Sq)tember 23, 1980. Through exchange of Diplomatic Notes, on March 12, 1987, the Arrangement was extended to March 1991. In July 1992, another exchange

of Diplomatic Notes extended the Arrangement retroactively fhjm March 31, 1991 to March 31,

19%. In addition, the Arrangement was modified to terminate the quarterly exchange of data and

substitute an annual exchange of data.

The enclosed rqwrt summarizes current conditions and compares them to guidelines for specific

parameter values that were developed by the International Joint Commission under the 1977

Reference from Canada and the United States. After examination and evaluation of the monitoring information for 1995, the Committee finds that the measured conditions meet the recommmded objectives. However, the Committee notes that the flow-weighted concentration of total dissolved solids in streamflow in the East Poplar River at the International Boundary

continues to increase and is approaching the long-term objective of 1,000 milligrams per litre. The

Committee also notes that there is the need to finalize the three unresolved parameters - pH,

mercury in fish, and unionized ammonia.

During 1995, monitoring continued in accordance with Technical Monitoring Schedules outlined

in 1992 Annual Report of the Poplar River Bilateral Monitoring Committee.

Yours sincerely.

Robert Davis

Chairman^nited States Section

Richard Kellow

Chairman, Canadian Section

/Ce . ^ . ~X .:t-c

GirffFritz Member, Uni States Section

4^—2C

Darryl Nargang

Member, Canadian Section

TABLE OF CONTENTS

Highlights for 1995 iii

1.0 Introduction 1

2.0 Committee Activities 2

2.1 Memberships 2

2.2 Meetings 2

2.3 Review of Water-Quality Objectives 3 2.4 Data Exchange 3

3.0 Water and Air: Monitoring and Interpretations 5

3.1 Poplar River Power Station Operation 5

3.2 East Poplar River 5

3.2.1 Streamflow 5 3.2.2 Apportionment 6

3.2.3 Minimum Flows 6

3.2.4 On-demand Release 7

3.2.5 Water-Quality 8

3.2.5.1 Total Dissolved Solids 9

3.2.5.2 Boron 13

3.2.5.3 Other Water-Quality Variables 16

3.3 Ground-Water 18

3.3.1 Operations 18

3.3.2 Ground-water Levels 19

3.3.2.1 Saskatchewan 19

3.3.2.1.1 Frenchman Ground-Water Project 22

3.3.2.2 Montana 22

3.3.3 Ground-Water Quality 23

3.3.3.1 Saskatchewan 23

3.3.3.2 Montana 28

3.4 Cookson Reservoir 28

3.4.1 Storage 28

3.4.2 Water-Quality 30

3.5 Air-Quality 30

3.6 Quality Control 30

3.6.1 Streamflow 30

3.6.2 Water-Quality 31 ANNEXES

1.0 Poplar River Cooperative Monitoring Arrangement,

Canada-United States Al

2.0 Poplar River Cooperative Monitoring Arrangement, Technical Monitoring Schedules, 1996, Canada-United States A2

3 .0 Recommended Flow Apportionment in the Poplar River Basin A3
Table 2.1
HIGHLIGHTS FOR 1995

The Poplar River Power Station completed its twelfth full year of operation in 1995. The two

300-megawatt coal-fired units generated 4 472 200 gross megawatt hours of electricity which is about 102 percent of the 1994 power and 103 percent of 1993 power. The average capacity

factors for Units No. 1 and 2 was 87.2 percent and 85.3 percent, respectively.

Monitoring information collected in both Canada and the United States during 1995 was exchanged

in the spring of 1996. In general, the sampling locations, frequency of collection, and parameters met the requirements identified in the 1995 Technical Monitoring Schedules set forth in the 1994

annual report.

Streamflow in the Poplar River basin was below normal in 1995. The March to October recorded flow for the Poplar River at the International Boundary was 3 340 danf or 33 per cent of the 1931

to 1990 median seasonal flow. The 1995 recorded flow volume of the East Poplar River at the International Boundary was 2 530 dam^ This volume is 85 per cent of the median annual flow

since the completion of the Morrison Dam in 1975. The on-demand release, in accordance with

the apportionment recommendations of the International Joint Commission (UC), entitled Montana to a release of 617 dam^ from Cookson Reservoir during the twelve month period

commencing June 1, 1994. Montana requested this release to be made between April 11 and May

31, 1995. In addition to the minimum flow, a volume of 628 danf was delivered during this period.

It is noted that the 5-year moving flow-weighted concentrations of total dissolved solids for the East Poplar River at the International Boundary were continuing to approach the 1 000 milligrams per litre objective. The calculated 5-year flow-weighted concentration of total dissolved solids for 1995 was 989 milligrams per litre. However, the concentration of boron for 1995 was 1.84 milligrams per litre, below its objective of 2.5 milligrams per litre.

1.0 INTRODUCTION

The Poplar River Bilateral Monitoring Committee was authorized for an initial period of five years by the Governments of Canada and the United States under the Poplar River Cooperative

Monitoring Arrangement dated September 23, 1980. A copy of the Arrangement is attached to

this report as Annex 1. On March 12, 1987, the Arrangement was extended by the Governments

for four years to March 1991. The Arrangement was further extended for another five years to March 1996, following a request from the Committee in 1991. A more detailed account of the

historical background of the Monitoring Arrangement is contained in the 1990 Annual Report of

the Poplar River Bilateral Monitoring Committee.

The Committee oversees monitoring programs designed to evaluate the potential for transboundary

impacts from SaskPower's (formerly Saskatchewan Power Corporation) coal-fired thermal

generating station and ancillary operations near Coronach, Saskatchewan. Monitoring is conducted in Canada and the United States at or near the International Boundary for quantity and

quality of surface and ground water and for air quality. Participants from both countries,

including Federal, State and Provincial agencies, are involved in monitoring.

The Committee submits an annual report to Governments which summarizes the monitoring

results, evaluates apparent trends, and compares the data to objectives or standards recommended

by the International Joint Commission (UC) to Governments, or relevant State, Provincial, or

Federal standards. The Committee reports to Governments on a calendar year basis. This report

is the fifteenth in the series. The Committee is also responsible for drawing to the attention of Governments definitive changes in monitored parameters which may require immediate attention.

A responsibility of the Committee is to review the adequacy of the monitormg programs in both

countries and make recommendations to Government on the Technical Monitoring Schedules. The

Schedules are updated annually for new and discontinued programs and for modifications in sampling frequencies, parameter lists, and analytical techniques of ongoing programs. The

Technical Monitoring Schedules listed in the annual report (Annex 2) are given for the forthcoming year. The Committee will continue to review and propose changes to the Technical Monitoring Schedules as information requirements change.
2.0 COMMITTEE ACTrvrriES

2.1 Membership

The Committee is composed of representatives of the Governments of the United States of America and Canada, the State Government of Montana, and the Provincial Government of Saskatchewan. In addition to the representatives of Governments, two ex-officio members serve

as local representatives for the State of Montana and Province of Saskatchewan.

During 1995, the members of the Committee included: Mr. J. A. Moreland, U.S. Geological

Survey, United States representative and Cochair; Mr. R. Kellow, Environment Canada,

Canadian representative and Cochair; Mr. G. Fritz, Montana Department of Natural Resources and Conservation, Montana representative; Mr. D. D. Nargang, Saskatchewan Environment and Resource Management, Saskatchewan representative; Mr. C.W. Tande, Daniels County

Commissioner, Montana local ex-officio representative; and Mr. J.R. Totten, Reeve, R.M. of Hart

Butte, Saskatchewan local ex-officio representative.

2.2 Meetings

The Committee met on August 2 and 3, 1995, in Helena, Montana. Delegated representatives of Governments, with the exception of the two ex-officio members from Montana and Saskatchewan,

attended the meeting. In addition to Committee members, several technical advisors representing

Federal, State and Provincial agencies participated in the meeting. During the meeting, the Committee reviewed the operational status of the Poplar Power Plant and associated coal mining

activities; examined data collected in 1994 iiKluding surface water-quality and quantity, ground

water-quality and quantity, and air quality; established the Technical Monitoring Schedules for 1996; discussed proposed changes in water-quality objectives and the possibility of replacing the flow-weighing method currently used to compute total dissolved solids and boron. The Committee

also prepared the first draft of the 1994 annual Report to Governments.
2.3 Review of Water-Oualitv Objectives

The International Joint Commission in its Report to Governments, titled " Water-Quality in the Poplar River Basin", recommended that the Committee "periodically review the water-quality

objectives within the overall Basin context and recommend new and revised objectives as appropriate". In 1991, the Committee undertook a review of water-quality objectives.

The Committee approved changes in water-quality objectives recommended by the 1991 subcommittee which was formed to review the objectives. Revised objectives approved by the Committee are listed in Table 2.1.

The Committee discussed the water-quality objectives for 5-year and 3-month flow-weighted

concentrations for total dissolved solids and boron. Although the Committee agreed that calculation procedures to determine flow-weighted concentrations are time consuming and

probably scientifically questionable, no consensus was reached on alternative objectives or

procedures. Objectives for unionized ammonia, pH, and mercury in fish tissue and the rational for using flow-weighted averages in the determinations of total dissolved solids and boron will require

additional study.

Another responsibility of the Committee has included an ongoing exchange of data acquired

through the monitoring programs. Exchanged data and reports are available for public viewing

at the agencies of the participating governments or fi-om Committee members.

2.4 Data Exchange

The Committee is responsible for assuring exchange of data between governments. The exchange

of monitoring information was initiated in the first quarter of 1981 and was an expansion of the informal quarterly exchange program initiated between the United States and Canada in 1976.

Until 1991, data were exchanged on a quarterly basis. At the request of the Committee, the United States and Canada agreed to replace the quarterly exchange of data with an annual exchange effective at the beginning of the 1992 calendar year. Henceforth, data will be exchanged once each year as soon after the end of the calendar year as possible. However, unusual

conditions or anomalous information will be reported and exchanged whenever warranted. No

unusual conditions occurred during 1995 which warranted special reporting.
Table 2.1 Water-quality Objectives

PARAMETER
3.0 WATER AND AIR: MONITORING AND INTERPRETATIONS

3.1 Poplar River Power Station Operation

In 1995, the average capacity factor for Unit No. 1 was 87.2 percent. The average capacity factor for Unit No. 2 was 85.3 percent. The capacity factors are based on the maximum generation

rating of 297.8 MW/h for Unit No. 1 and 294.0 MW/h for Unit No. 2. Total power generated

from both units was 4 472 200 gross megawatt-hours which is about 102 percent of 1994 power

and 103 percent of 1993 power.

There was no major construction activity during 1995 as compared to 1994 when Ash Lagoon #3

South was constructed. A minor construction project was started in the fall of 1995 to install a new discharge culvert between Ash Lagoons 1 and 2.

3.2 East Poplar River

3.2.1 Streamflow

Streamflow in the Poplar River basin was below normal in 1995. The March to October recorded flow of the Poplar River at the International Boundary, an indicator of natural flow in the basin, was 3 340 cubic decameters (dam^) or 33 percent of the 1931 to 1990 median seasonal flow. However, timely precipitation sustained above-average flows in the normally dry late-summer months after below-average snowmelt runoff in the spring. A comparison of 1995 mean monthly

discharge with the l%l-90 median flow is shown in Figure 3.1.
MAR APR MAY JUN JUL AUG SEP OCT

Figure 3. 1 Discharge during 1995 as Compared with the Median Discharge from 1931- IS^ for Poplar River at the International Boundary.

The 1995 recorded flow volume of the East Poplar River at the International Boundary was 2 530

dam'. This volume is 85 % of the median annual flow since the completion of Morrison Dam in 1975.

3.2.2 Apportionment

In 1976 the International Souris-Red Rivers Engineering Board, through its Poplar River Task

Force, completed an investigation and made a recommoidation to the Governments of Canada and

the United States regarding the aj^rtionment of waters of the Poplar River basin. Although not

officially adopted by the two countries, the Poplar River Bilateral Monitoring Committee has adhered to the Apportionment Recommendations in each of its annual reports. Annex 3 contains

the apportionment recommendation.

3.2.3 Minimum Flows

The recorded volume of the Poplar River at the International Boundary from March 1 to May 31, 1995 was 2 110 dam^ Based on UC recommendations and the assumption that the recorded flow

is the natural flow, the United States was entitled to a minimum discharge on the East Poplar of 0.028 mVs for the period June 1, 1995 to May 31, 1996. The minimum flow for the period

January 1 to May 31, 1995 had previously been determined on the basis of the Poplar River flow volume for March 1 to May 31, 1994. A hydrograph of the East Poplar River at the International Boundary and the minimum flow as recommended by the UC are shown in Figure 3.2.
Daily flows during 1995 cwcasionally fell below the recommended minimum during the winter months because of beaver activity, ice conditions, and severe cold spells. The deficit volume for January through March, 1995, was 10 dam' - an average of 0.001 mVs per day.

FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV OEC

Figure 3.2 Flow Hydrograph of the East Poplar River at the International Boundary.

3.2.4 On Demand Release

In addition to the minimum flow, the UC apportionment recommendation entitles Montana to an on demand release to be delivered during the twelve month period commencing June 1. Based on

the runoff volume of 13 200 dam' recorded at the Poplar River at the International Boundary

gaging station during the March 1 to May 31, 1994 period, Montana was entitled to a release of 617 dam' from Cookson Reservoir during the twelve month period commencing June 1, 1994. Montana requested this release to be made between April 11 and May 31, 1995. In addition to

the minimum flow, a volume of 628 dam' was delivered during this period.
3.2.5 Water-Quality

The 1981 report by the UC to Governments recommended:

For the March to October period, the maximum flow-weighted concentrations should not exceed 3.5 milligrams per litre (mg/L)for boron and 1500 mg/Lfor

TDS for any three consecutive months in the East Poplar River at the International Boundary. For the March to October period, the long-term average offlow-weighted concentrations should be 2.5 mg/L or less for boron,

and 1000 mg/L or less for TDS in the East Poplar River at the International Boundary.

For the period prior to 1982, three-month moving flow-weighted concentrations (FWC) for boron and TDS were calculated solely from monthly monitoring results. Since the beginning of 1982,

the US Geological Survey (USGS) has monitored specific conductance daily in the East Poplar

River at the International boundary, allowing estimates of daily boron and TDS concentration to be derived from the regression relationship with specific conductance. Thus, three-month FWCs

for the period 1982 to 1995 have been calculated from both the results of monthly monitoring and

the daily concenfration estimates.

The Bilateral Monitoring Conmiittee adopted the approach that for the purpose of comparison

with the proposed UC long-term objectives, the boron and TDS data are best plotted as five-year

moving FWCs which were advanced one month at a time. Prior to 1988, long-term averages were

calculated for a five year period in which 2.5 years preceded and 2.5 years followed each plotted

point. Beginning in 1988, FWCs were calculated from the five year period preceding each plotted

point. For example, the FWC for December 1995 refers to the FWC of the period December 1990

to December 1995. The calculations are based on the results of samples collected throughout the year, and are not restricted to only those collected during the months bracketing the period of

irrigation (March to October) each year.
3.2.5.1 Total Dissolved Solids

There is an inverse relationship between TDS and streamflow at the International Boundary

station. During periods of high runoff, such as spring freshet, TDS drops as the proportion of

streamflow derived ultimately from ground-water decreases. Conversely, during times of low

streamflow Gate summer, winter) the contribution of ground-water to streamflow is proportionaUy

greater. Because the natural ground-water has a higher ionic strength than the surface water

entering the river, the TDS of the stream increases markedly during low flow conditions.

TDS grab sample data collected by Environment Canada and the USGS in 1995 are shown in Figure 3.3. TDS ranged from 899 mg/L on 6-July to 1 194 mg/L on 9-May. The proposed short- term objective for TDS is 1 500 mg/L. A time plot of the three-month moving FWCs for TDS is presented in Figure 3.4. No exceedences of the objective have been observed during any three month period since 1975. The three-month FWCs remained confined within a narrow range

centred around a mean of approximately 984 mg/L (regression generated data) and 1 039 mg/L

(grab sample data).
10

Figure 3.3: TDS Concentrations for 1995 Grab Samples from

East Poplar River at the International Boundary

1400

1200

1000

800

600

400

200

05/09 i 02/14 A
11

Five-year FWC's for TDS at 989 mg/L (Figure 3.5) for 1995 continued to approach, but remained below the long-term objective of 1000 mg/L. The maximiim monthly value calculated

in 1995 was 981 mg/L. This gradual increase in five-year FWC for TDS is due to low surface runoff in the late eighties/early nineties, particularly reflected in the spring flows, which has not allowed for sufflcient flushing of Cookson Reservoir.

A linear regression analysis was applied to the daily TDS values, as generated from the daily

specific conductance readings from 1982 to 1995 (Figure 3.6). The regression line shows a

gradual increase in TDS over this period. The positive trend is probably due to drought conditions

in southern Saskatchewan during the latter part of the 1980' s, and the early 1990' s. Hence, a

larger overall contribution of ground-water to the flow in the East Poplar River. The upward trend could also be attributed in part to higher rates of evaporation from Cookson Reservoir during the

hot, dry period of the late 1980's, and to the fact that the Reservoir has received very little flushing over the period of record, due to the need to conserve cooling water. It should be

understood though, that this regression line has a low R-squared value, which means that it is only a very general indicator of long-term trends, and should not be thought of as a predictive tool.

The relationship between TDS and conductivity generated from data collected from 1975 to 1995

is as follows:

TDS = (0.639 X specific conductance) + 11.286

(R} = 0.87, n = 517)
12

I Figure 3.5: Five-Year Moving Flow-Weighted TDS Concentrations for East Poplar

! River at the International Boundary

1200

1000 -

«d 800

o>

E,c% 600

o 400 O

200 -

1 1 1 1 i i i 1 1 i i Ml
13

3.2.5.2 Boron

During 1995, boron concentrations in the East Poplar River at the International Boundary

varied from 0.94 (9-May) to 2.2 mg/L (14-February, and 14-December) (Figure 3.7).

Three-month boron FWC's for the period of record are shown in Figure 3.8. The short-term

objective of 3.5 mg/L was not exceeded for the period 1975-1995. It can be seen that the data derived from grab samples and that derived from regression with specific conductance are

similar, with the highs and lows in some degree of correspondence. This indicates that the regression generation of boron (and TDS) values is in general terms, a valid procedure.

The five-year boron FWC's displayed in Figure 3.9 remained well below the long-term

objective of 2.5 mg/L. From mid 1993 to the end of the data period there is a distinct drop in

tlie computed values.

The relationship between boron and conductivity at the East Poplar River sampling location during the period 1975 to 1995 is described by the equation:

boron = (0.0013 x specific conductance) - 0.092

(R^ = 0.61, n = 517)

As shown in Figure 3.10, the straight line generated by the regression analysis of boron

(dependent variable) over time (independent variable) shows a positive slope of 0.025

mg/L/year. Again, as was the case with TDS, this is only a general indicator of a long-term

behaviour. It should not be considered a predictive tool, without a more detailed analysis of weather, ground-water conditions, and conditions imposed by the power station.
14

Figure 3.7: Boron Concentrations for 1995 Grab Samples from East Poplar River at the International Boundary

2.5

B

o 1.5

o

1 U

S

1 —

0.5

i 02/14 •

104/11
15

Figure 3.9: Five-Year Moving Flow-Weighted Boron Concentration for East Poplar

River at the International Boundary

2 -

! «

ea 1
16

3.2.5.3 Other Water-Quality Variables

Table 3.1 contains the multipurpose water-quality objectives for the East Poplar River at the

International Boundary, recommended by the International Poplar River Water-Quality Board

to the IJC. The table shows the number of samples collected for each parameter and the number of exceedences over the course of the year. In the table, multiple replicate samples

collected during the annual quality control exercise are treated as a single sample, but any

exceedences noted in the suite of replicate sample is charged against the single sample noted. There were no exceedences for any parameter measured. The January 17 Canadian sample

revealed a dissolved oxygen concentration of 4 mg/L, which is equal to the objective value. Dissolved oxygen levels can be expected to be lower during ice-covered conditions, and lowflow summer conditions where oxygen has been reduced by biological activity.

Table 3.1 lists the updated multipurpose water-quality objectives for the East Poplar River at

the International Boundary, recommended by the International Poplar River Water-Quality

Board to the UC. Revisions to the objectives were made in 1992 as outlined in the 1992

annual report. Objectives for un-ionized ammonia, mercury in fish, and pH require further

definition. No excursions occurred in 1995.
17

Table 3.1 Recommended Water-Quality Objectives and Excursions, 1995 Sampling Program, East Poplar River at the International Boundary (units in mg/L except as otherwise noted) ||
18

3.3 Ground-water

3.3.1 Operations

In 1995, SaskPower continued to operate their supplementary ground-water supply to Cookson

Reservoir. The 1995 total of 5 376 dam? of ground-water produced from the supplementary

supply was slightly less than the 1994 production of 5 485 danf . SaskPower has an approval to produce an aimual volimie of 5 500 dam?.

SaskPower's well network currently consists of 21 wells, with a total of 10 discharge points. No

wells were added or deleted from the well field during the year. Production was reasonably

consistent throughout most of the year with the exception of July and August when there was a reduction in pumping. In July and August, with the exception of well UA, wells which do not supply water to domestic users were turned off. Therefore, from mid-July to late August, only

5-6 wells were pumped, as opposed to the remainder of the year when up to 19 wells were pumped. Reduced summer pumping assists in maximizing flows into Cookson Reservoir by

minimizing evaporative losses in Girard Creek and ensures that the SaskPower's allocation is not exceeded.

Operation of SaskPower's salinity project continued in 1995 with production from 7 wells, with

a total volume of 1 017 dan^ pumped during the year. This represents a slight reduction from the 1994 pumped volume of 1 095 dam?. (An eighth well is located along the International Boundary,

but has never been operated). As in previous years, the majority of the water was pumped from

wells PW87103 and PW87104 on the east side of the river and PW90108 on the west side of the

river.
19

3.3.2 Ground-Water Levels

3.3.2.1 Saskatchewan

There does not appear to be any major changes in the cone of depression in the Hart Coal seam

as a result of the supplementary supply project. The 1 m drawdown contour is at or near the

International Boundary, much as it has been for the past several years (Figure 3.11). As a result of the map for 1996 being generated by a computer contouring package, there are some differences

in the manner in which the contours are drawn, but these differences are minor. The reasonably

consistent drawdowns over the past several years (over which the volumes pumped have been

fairly consistent) indicate the aquifer system has approached a semi-equilibrium state.

The December 1995 drawdown map for the Empress sands (Figure 3.12) indicates that there was

a significant increase in both the extent and magnitude of drawdowns from salinity project

pumping. This increase occurred even with a slight reduction of pumping, which demonstrates

the impacts of fluctuations in recharge on the project. Recharge in 1995 was lower than in 1993 and 1994. The goal of the project is to lower water levels in the Empress sands below the reservoir by 2-3 metres. This had been established prior to the significant recharge which started

in June 1993, and led to drawdowns below the targeted level of 2-3 metres. The drawdown map

shows that a 2-3 metre drawdown cone has been re-established on the west side, while drawdowns

are 1-1 V2 metres on the east side. Pumping will target maintenance of the present drawdowns on

the west side and expansion of drawdowns on the east to 2-3 metres.
o

%
«
22

3.3.2.1.1 Frenchmaii Groundwater Project

Given the low water levels in Cookson Reservoir throughout the early to mid-1990s,

SaskPower undertook an evaluation of the Frenchman (Hell Creek) formation as an additional supplementary supply and subsequently submitted an application for 360 dam'/year from the aquifer . There was some written opposition to the project from local residents and concerns were also submitted by the State of Montana and the United States Geological Survey due to potential drawdowns occurring across the International Boundary. The application is still under consideration.

3.3.2.2 Montana

After an increase in water levels in 1994 due to an excellent recharge year, water levels in Wells 5, 8, 16, 19, 22, and 23 declined in 1995 reflecting a return to normal seasonal

fluctuations. Monitoring Wells 6, 7, 9, 11, 13 and 17 fluctuated in response to seasonal changes (Figure 3.13).

2460 _ 2458

1

2456

^^S

2 2454

>U

i; 2452

it g 2450

O

2448

2446
23

3.3.3 Ground-Water-Quality

3.3.3.1 Saskatchewan

The Water-quality from the Supplementary Water Supply Project discharge points has been

consistent with no trends indicated. A summary of the more frequently tested parameters

during 1995 is provided in Table 3.2. Statistical averages of the results since 1990 are included in this table. Water-quality from the wells has a positive influence on the quality of

water in the reservoir for most parameters.

Table 3.2 Water-Quality Statistics for Water Pumped

Supplementary Water Supply Project Wells
24

The Water-Quality of the common discharge point from the Salinity Control Project wells is generally better than the Water-Quality in Cookson Reservoir. Average results from the common discharge point for 1995, plus an average of the 1990-1995 results, are provided in Table 3.3. Results have been consistent since 1990.

Table 3.3 Water-Quality Statistics for Water Pumped from

Salinity Control Project Wells Sampled at the Discharge Pipe
25

Ground-water quality in the vicinity of the ash lagoons can potentially be affected by leachate movement through the ash lagoon liner systems. The piezometers listed in the Technical Monitoring Schedules are used to assess leachate movement and calculate seepage rates. Piezometric water level, boron and chloride are the chosen indicator parameters to asses leachate movement.

The ground-water monitoring program was expanded in 1994 as a result of Ash Lagoon #3 South

construction. In total 20 new pneumatic piezometers and 28 new standpipe piezometers were

completed within their target zones. Testing of these piezometers began in 1995. Due to the

limited amount of data collected to date from these piezometers, a meaningfiil review is not yet

possible.

Piezometers 867A, 868A and 871A are completed immediately above the liner system, within the ash stack of Ash Lagoon #1 . The 1995 monitoring results continue to suggest confirmation of the trend first observed in 1993 that the boron concentration decreases with depth within the ash stack. The effect of ash thickness on leachate quality is, however, not completely understood.

The chemistry of water immediately above the liner systems is therefore suspected to differ from

the surface water of the lagoons. Meaningful information is only available from piezometers

installed within Ash Lagoon #1 where ash has been deposited for many years. New piezometers

886A, 887A, 890A and 893A have been completed above the liner system of new Ash Lagoon #3

South and are now being monitored. Future monitoring of all piezometers completed above the lagoon liner systems will continue with the purpose of confirming the boron trend noted above and

to improve the understanding of leachate quality and flow from the ash lagoons.

The piezometric surface measurements for the oxidized till continue to show the presence of a ground-water mound beneath the ash lagoons. Relative to the 1994 position, the size and extent of the ground-water mound has not significantly changed. The mound extends from the east side of Ash Lagoon 2, where levels have increased 7 metres, to the west side of the polishing pond,

where levels have increased 4 metres. Oxidized till piezometers located closer to the reservoir have shown a decreasing trend in piezometric levels reacting to lower reservoir levels.
26

The greatest changes in chloride and boron concentrations within the oxidized till, have occurred where piezometric levels have changed the most. This is an expected result as changing

piezometric levels suggest ground-water movement. Increasing boron concentrations on the east and south side of Ash Lagoon 2, together with decreasing chloride concentrations suggests leachate influence. On the west-side of the polishing pond the boron concentrations have not

significantly changed.

Little change in boron or chloride concentrations has been observed for most of the oxidized till piezometers located by the reservoir. The most significant change in samples from any of these piezometers has been C719 where chloride concentrations have decreased 93 mg/1 overall since 1983 to 18 mg/1. The change in quality is suspected to be the result of reservoir influence rather than ash lagoon influence.

A ground-water mound has developed in the unoxidized till, similar to that in the oxidized till, extending from the east side of Ash Lagoon 2 to the west side of the Polishing Pond. The ground- water mound is known to be discontinuous as piezometers 764D and 871C are located within the mound area and are reacting to reservoir levels. A review of boron and chloride concentrations does not show any significant trends.

The piezometric surface of the Empress gravels indicate a regional flow from northwest to southeast below Morrison Dam. Monitoring since 1983 generally shows that the piezometric

surface in the lagoon area reacts to the reservoir level. Results for Empress gravel Water-Quality

do not indicate any leachate influence with the majority of piezometers showing little change in boron or chloride concentrations from background values.

Sand lens piezometers C712B, C766 and C767 are located between the polishing pond and the cooling water canal. C767 is located on the top of dyke G and C766 and C712B are located at the

toe of dyke G. These piezometers have historically been of interest as the sand lens provides a

preferential pathway for leachate migration.

A review of the boron concentrations for C766 shows an increasing trend up to October 1988 when levels peaked at 12.6 mg/1. Boron concentration decreased to 6.99 mg/1 in April 1990, then began increasing again peaking at 35.2 mg/1 in June 1993 before falling to 26.7 mg/1 in October

1993. The boron concentration began an increasing trend throughout 1994 and peaked at 43 mg/1
27

in May, 1995, the highest recorded concentration to date, before decreasing to near 35 mg/1 in October, 1995. The chloride concentration for C766 has shown little movement since 1987 and

remains within the 20 to 30 mg/1 range, similar to the ash lagoon surface water concentration.

Up to April 1988 the boron concentration for C767 was increasing and peaked at 49.4 mg/1. From

this peak the boron concentration has steadily decreased to the end of 1991 where the concentration levelled off near 5 mg/I. The October 1995 result is 5.28 mg/1. The reduction in boron concentrations for samples from C767 suggest the movement of a slug of leachate and not

a continuous plume. There has been an increasing trend in chloride for C767 ranging from 25

mg/1 in 1989 to 75 mg/1 in 1991. Since 1991 the concentration has remained near 70 mg/1 with an October 1994 result of 73.4 mg/1. In 1995 the concentration showed a moderate increase, ranging between 94 and 99 mg/1.

Boron concentrations for piezometer 712B were initially below 1.0 mg/1 until an increasing trend began in 1987 with the concentration peaking in April 1992 at 26.6 mg/1. The boron

concentration then decreased and levelled off near 18 mg/1 with an October 1995 result of 20 mg/1. Chloride concentrations trended down for C712B to 50 mg/1 in 1988 from over 200 mg/1 in 1984. Since 1988 chloride levels have changed little with an October 1995 result of 50.8 mg/1.

In 1994 it was reported that no vertical seepage or liner permeability could be calculated for Ash

Lagoon #3 North due to the measured pore pressure exceeding what the lagoon water level could

physically produce. As expected this situation has corrected.

The total calculated seepage from the ash lagoons in 1995 was determined to be 1.61 litres per

second. This value is not significantly different from the 1994 and 1993 calculated seepage rates of 1.67 and 1.62 litres per second, respectively. There was a negligible total calculated seepage

rate for Ash Lagoon #3 South at 0.001 litres per second. This result was not unexpected as the lagoon has only been in service since May, 1995 and no gradients have developed.

Liner permeabilities for all lagoons except Ash Lagoon 3 South remain in the order of lO^cm/sec. The liner permeability determined for Ash Lagoon 3 South, based on the above permeability, is not considered realistic and was not reported.
28

3.3.3.2 Montana

Samples were collected firom monitoring wells 7, 16, and 24 during 1995. Well 7 is completed

in Hart Coal, well 16 is completed in the Fort Union Fonnation, and well 24 is completed in alluvium. No significant changes in water quality was observed. Graphs of total dissolved solids for selected wells are shown in Figure 3. 14.

1000

800

M 600

400

200
29

Table 3.4 Cookson Reservoir Storage Statistics for 1995

Date
30

3.4.2 Water-Quality

The 1995 spring runoff had little positive impact on Cookson Reservoir water-quality. At the end

of 1995, boron concentrations in the reservoir were about 2.4 mg/L compared to about 2.4 mg/L

at the end of 1994. Similarly, TDS increased from 1 250 mg/L at the end of 1994 to about 1 400

mg/L at the end of 1995. Water-quality conditions at the end of 1995 were similar to year-end

conditions in 1993 and early 1992.

3.5 Air-Quality

SaskPower's ambient SOj monitoring for 1995 recorded no violations of SERM's hourly and 24- hour average standards at 0.17 and 0.06 ppm, respectively. The highest hourly value was

recorded at 0.0413 ppm in June, 1995.

Total suspended particulate concentrations for 1995 obtained from SaskPower's monitor did not exceed SERM's 24-hour standard of 120ug/m^ The highest recorded concentration was 60.6 ug/m' in June, 1994. The geometric mean for the high-volume suspended particulate sampler was

15.7 ug/m^

3.6 Quality Control

3.6.1 Streamflow

To test the comparability of Streamflow measurements made by the U.S. Geological Survey

(USGS) and Environment Canada (EC), similar measurements were made on the East Poplar River

at the International Boundary on August 23, 1995 by personnel from both agencies. The discharge

data shown in Table 3.5 are similar although not identical indicating the difficulty of obtaining

the same measurements of small discharge using conventional current-metre methods. The

computations were made using the theoretical discharge of the 9CP V-notch weir of 0.067 ra?/s.
31

Table 3.5 Streamflow Measurement Results for August 23, 1995

Agency

ANNEX 1

POPLAR RIVER

COOPERATIVE MONITORING ARRANGEMENT

CANADA-UNITED STATES

Al-1
September 23, 1980

POPLAR RIVER COOPERATIVE MONITORING ARRANGEMENT

I. PURPOSE

This Arrangement will provide for the exchange of data collected as described in the attached Technical Monitoring Schedules in Water-Quality, water quantity and air quality monitoring programs being conducted in Canada and the United States at or near the International Boundary

in response to SaskPower development. This Arrangement will also provide for the dissemination of the data in each country and will assure its comparability and assist in its technical

interpretation.

The Arrangement will replace and expand upon the quarterly information exchange program

instituted between Canada and the United States in 1976.

n. PARTICIPATING GOVERNMENTS

Governments and government agencies participating in the Arrangement are:

Government of Canada: Environment Canada

Government of the Province of Saskatchewan: Saskatchewan Environment and Resource Management

Government of the United States of America: United States Geological Survey Government of the State of Montana: Executive Office

m. POPLAR RIVER MONITORING COMMITTEE: TERMS OF REFERENCE

A binational committee called the Poplar River Bilateral Monitoring Committee will be established

to carry out responsibilities assigned to it under this Arrangement. The Committee will operate

in accordance with the following terms of reference:

A1-2
A. Membership

The Committee will be composed of four representatives, one from each of the participating Governments. It will be jointly chaired by the Government of Canada and the Government of the United States. There will be a Canadian Section and a United States Section. The participating Governments will notify each other of any changes in membership on the Committee. Cochairpersons may by mutual agreement invite agency technical experts to participate in the work

of the Committee.

The Governor of the State of Montana may also appoint a chief elective official of local government to participate as an ex-officio member of the Committee in its technical deliberations. The Saskatchewan Minister of the Environment may also appoint a similar local representative.

B. Functions of the Committee

The role of the Committee will be to fulfil the purpose of the Arrangement by ensuring the exchange of monitored data in accordance with the attached Technical Monitoring Schedules, and

its collation and technical interpretation in reports to Governments on implementation of the Arrangement. In addition, the Committee will review the existing monitoring systems to ensure

their adequacy and may recommend to the Canadian and United States Governments any

modifications to improve the Technical Monitoring Schedules.

1. Information Exchangg

Each Co-chairperson will be responsible for transmitting to his counterpart Co-chairperson on a

regular, and not less than quarterly basis, the data provided by the cooperative monitoring

agencies in accordance with the Technical Monitoring Schedules.
2. E£I2Q£tS

(a) The Committee will prepare a joint Annual Report to the participating

governments, and may at any time prepare joint Special Reports.

(b) Annual Reports will

i) summarize the main activities of the Committee in the year under Report and the data which has been exchanged under the Arrangement;

ii) draw to the attention of the participating governments any definitive changes in the monitored parameters, based on collation and technical interpretation of exchanged

data (i.e. the utilization of summary, statistical and other appropriate techniques);

iii) draw to the attention of the participating governments any recommendations

regarding the adequacy or redundancy of any scheduled monitoring operations and any proposals regarding modifications to the Technical Monitoring Schedules, based on a continuing review of the monitoring programs including analytical

methods to ensure their comparability.

c) Special Reports may, at any time, draw to the attention of participating

governments definitive changes in monitored parameters which may require

immediate attention.

d) Preparation of Reports

Reports will be prepared following consultation with all committee members and

will be signed by all Committee members. Reports will be separately forwarded by the Committee Co-chairmen to the participating governments. All annual and

special reports will be so distributed.
3. Activities of Canadian and United States Sections

The Canadian and United States section will be separately responsible for:

(a) dissemination of information within their respective countries, and the arrangement

of any discussion required with local elected officials;

(b) verification that monitoring operations are being carried out in accordance with the Technical Monitoring Schedules by cooperating monitoring agencies;

(c) receipt and collation of monitored data generated by the cooperating monitoring

agencies in their respective countries as specified in the Technical Monitoring

Schedules;

(d) if necessary, drawing to the attention of the appropriate government in their respective covmtries any failure to comply with a scheduled monitoring function on

the part of any cooperating agency under the jurisdiction of that government, and

requesting that appropriate corrective action be taken.

IV. PROVTSTON OF DATA

In order to ensure that the Committee is able to carry out the terms of this Arrangement, the

participating governments will use their best efforts to have cooperating monitoring agencies, in

their respective jurisdictions provide on an ongoing basis all scheduled monitored data for which

they are responsible.

V. TERMS OF THE ARRANGEMENT

The Arrangement will be effective for an initial term of five years and may be amended by

agreement of the participating governments. It will be subject to review at the end of the initial term and will be renewed thereafter for as long as it is required by the participating governments.

Al-5

ANNEX 2

POPLAR RIVER

COOPERATIVE MONITORING ARRANGEMENT

TECHNICAL MONITORING SCHEDULES

1996

CANADA-UNITED STATES

A2-1
TABLE OF CONTENTS

PREAMBLE X2 - 3 CANADA

STREAMFLOW MONITORING A2 - 5

SURFACE-WATER-QUALITY MONITORING A2 " 1

GROUND-WATER PIEZOMETERS TO MONITOR

POTENTIAL DRAWDOWN DUE TO COAL SEAM DEWATERING A2 - 10

GROUND-WATER PIEZOMETERS LEVEL MONITORING

- POWER STATION AREA A2 - 12

GROUND-WATER PIEZOMETER LEVEL MONITORING

- ASH LAGOON AREA A2 - 14

AMBIENT AIR-QUALITY MONITORING A2 - 23

UNITED STATES

STREAMFLOW MONITORING A2 - 26

SURFACE-WATER-QUALITY MONITORING A2 - 28

GROUND-WATER-QUALITY MONITORING A2 - 30

GROUND-WATER LEVELS TO MONITOR POTENTIAL

DRAWDOWN DUE TO COAL SEAM DEWATERING A2 - 32

A2-2
PREAMBLE

The Technical Monitoring Schedule lists those water quantity, Water-Quality and air quality

monitoring locations and parameters which form the basis for information exchange and reporting

to Governments. The structure of the Committee responsible for ensuring the exchange takes place

is described in the Poplar River Cooperative Monitoring Arrangement.

The monitoring locations and parameters listed herein have been reviewed by the Poplar River

Bilateral Monitoring committee and represent the basic technical information needed to identify any defmitive changes in water quantity, Water-Quality and air quality at the International Boundary. The Schedule was initially submitted to Governments for approval as an attachment to

the 1981 report Governments. Changes in the sampling locations and parameters may be made by Governments based on the recommendations of the committee.

Significant additional information is being collected by agencies on both sides of the International Boundary, primarily for project management or basin-wide baseline data purposes. This additional information is usually available upon request from the collecting agency and forms part of the pool of technical information which may be drawn upon by Governments for specific study purposes. Examples of additional information are water quantity, Water-Quality, ground-water and air

quality data collected at points in the Poplar River basin not of direct concern to the Committee.

In addition, supplemental information on parameters such as vegetation, soils, fish and waterfowl

populations and aquatic vegetation is also being collected on either a routine or specific studies basis by various agencies.

A2-3
POPLAR RIVER

COOPERATIVE MONITORING ARRANGEMENT

TECHNICAL MONITORING SCHEDULES

1996

CANADA

A2-4
STREAMFLOW MONITORING

Responsible Agency: Environment Canada

Daily mean discharge or levels and instantaneous monthly extremes as normally

published in surface water data publications.

No. on Map
10 Mil«t

HYDROMETRIC GAUGING STATIONS (CANADA)

A2-6
SURFACE-WATER-QUALITY

Sampling Locations

1 Responsible Agency: Saskatchewan Environment and Resource Management J
PARAMETERS
A2-9
GROUND-WATER PIEZOMETERS TO MONITOR POTENTIAL DRAWDOWN

DUE TO COAL SEAM DEWATERING

Responsible Agency: Saskatchewan Environment and Resource Management
V.

GROUND-WATER PIEZOMETERS TO MONITOR POTENTIAL

DRAWDOWN DUE TO COAL SEAM DEWATERING

A2-11
GROUND-WATER PIEZOMETER MONITORING - POPLAR RIVER

POWER STATION AREA

SPC Piezometer Number
g

LJ 2

c

.0^^.^^

.0^

^^0^^<l^^

in vJino
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-WATER LEVEL

SPC Piezometer Number
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-WATER LEVEL (Continued)

SPC Piezometer Number
GROUND-WATER PIEZOMETER MONITORING--

ASH LAGOON AREA-WATER LEVEL (Continued)

SPC Piezometer Number
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-WATER LEVEL (Continued)

SPC Piezometer Number Completion Formation

888D Unoxidized Till Empress

B6^ Oxidized Till 155C"

555^

Oxidized Tril "

Unoxidized Till 889r Empress

Oxidized Till Oxidized Till "55(317 Unoxidized Till i5or Empress

"S5TB" Oxidized Till ^5TCr Oxidized Till 89TD^ Unoxidized Till 55Tr

"892r

8§2C"

Empress

Oxidized Till Oxidized Till M5D^ Unoxidized Till Empress

Oxidized Till 852EM3B

893C Oxidized Till Unoxidized Till Empress

893D

"893r

Oxidized Till Oxidized Till 894B

"8945"

Unoxidized Till Empress

894D

894E

1555" Oxidized Till 895(r Oxidized Till 855D Unoxidized Till gSST Empress

Water levels measured quarterly

A2-17
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-QUALITY

SPC Piezometer Numt>er
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-QUALITY (Continued)

SPC Piezometer Number
GROUND-WATER PIEZOMETER MONITORINGASH LAGOON AREA-QUALITY (Continued)

SPC Piezometer Number
A2-21
PARAMETERS

R«»pon»lbl« Agtncy: Saskatchewan Envlronmant and Rasourc* Managtmant ||
AMBIENT Am-QUALITY MO^fITORING

Responsible Agency: Saskatchewan Environment and Public Safety
^

10 Miles

AMBIENT AIR-QUALITY MONITORING (CANADA)

A2-24
POPLAR RIVER

COOPERATIVE MONITORING ARRANGEMENT

TECHNICAL MONITORING SCHEDULES

1996

UNITED STATES

A2-25
STREAMFLOW MONITORING

Responsible Agency: U.S. Geological Survey
5 10 15 Km

5 lO Miles

HYDROMETRIC GAUGING STATIONS (UNITED STATES)

A2-27

lO Miles

SURFACE-WATER-QUALITY MONITORING STATIONS (UNITED STATES)

A2-29
GROUND-WATER-QUALITY MONITORING - Station Locations —=JJ , Responsible Agency: Montana Bureau of Mines and Geology
5 10 -5 K'

10 Miles

GROUND-WATER-QUALITY MONITORING (UNITED STATES)

A2-31
GROUND-WATER LEVELS TO MONITOR POTENTIAL

DRAWDOWN DUE TO COAL SEAM DEWATERING

1 Responsible Agency: Montana Bureau of Mines and Geology
5 10 15 Km

10 Miles

GROUND-WATER PIEZOMETERS TO MONITOR POTENTIAL

DRAWDOWN DUE TO COAL SEAM DEWATERING

A2-33

AN>fEX3

RECOMMENDED FLOW APPORTIONMENT

IN THE POPLAR RIVER BASIN

BY THE INTERNATIONAL SOURIS-RED RIVERS ENGINEERING BOARD.

POPLAR RTVER TASK FORCE (1976)

A3-1
•RECOMMENDED FLOW APPORTIONMENT

IN THE POPLAR RTVER BASIN

The aggregate natural flow of all streams and tributaries in the Poplar River Basin crossing the International Boundary shall be divided equally between Canada and the United States subject to the following conditions:

1

.

The total natural flow of the West Fork Poplar River and all its tributaries crossing the International Boundary shall be divided equally between Canada and the United States but

the flow at the International Boundary in each tributary shall not be depleted by more than 60 percent of its natural flow.

2. The total natural flow of all remaining streams and tributaries in the Poplar River Basin

crossing the International Boundary shall be divided equally between Canada and the United States. Specific conditions of this division are as follows:

(a) Canada shall deliver to the United States a minimum of 60 percent of the natural flow of the Middle Fork Poplar River at the International Boundary, as determined below the confluence of Goose Creek and Middle Fork.

(b) The delivery of water from Canada to the United States on the East Poplar River

shall be determined on or about the first day of June of each year as follows:

(i) When the total natural flow of the Middle Fork Poplar River, as determined below the confluence of Goose Creek, during the immediately preceding

March 1st to May 31st period does not exceed 4,690 cubic decameters

(3,800 acre-feet), then a continuous minimum flow of 0.028 cubic metres

per second (1.0 cubic feet per second) shall be delivered to the United

States on the East Poplar River at the International Boundary throughout the succeeding 12 month period commencing June 1st. In addition, a volume

of 370 cubic decameters (300 acre-feet) shall be delivered to the United

States upon demand at any time during the 12 month period commencing

June 1st.

(ii) When the total namral flow of the Middle Fork Poplar River, as determined below the confluence of Goose Creek, during the immediately preceding

March 1st to May 31st period is greater than 4,690 cubic decameters (3,800

acre-feet), but does not exceed 9,250 cubic decameters (7,500 acre-feet).

Canada-United States, 1976, Joint studies for flow apportionment. Poplar River Basin, Montana-Saskatchewan: Main Report,

International Souris-Red Rivers Board, Poplar River Task Force, 43 pp.

A3 -2
then a continuous minimum flow of 0.057 cubic metres per second (2.0 cubic feet per second) shall be delivered to the United States on the East Poplar River at the

International Boundary during the succeeding period June 1st through August 31st. A minimum delivery of 0.028 cubic metres per second (1.0 cubic feet per second)

shall then be maintained from September 1st through to May 31st of the following

year. In addition, a volume of 617 cubic decameters (500 acre-feet) shall be

delivered to the United States upon demand at any time during the 12-month period

commencing June 1st.

(iii) When the total natural flow of the Middle Fork Poplar River, as determined below

the confluence of Goose Creek, during the immediately preceding March 1st to May 31st period is greater than 9,250 cubic decameters (7,500 acre-feet), but does

not exceed 14,8(X) cubic decameters (12,000 acre-feet), then a continuous minimum

flow of 0.085 cubic metres per second (3.0 cubic feet per second) shall be delivered

to the United States on the East Poplar River at the International Boundary during

the succeeding period June 1st through August 31st. A minimum delivery of 0.057

cubic metres per second (2.0 cubic feet per second) shall then be maintained from

September 1st through to May 31st of the following year. In addition, a volume

of 617 cubic decameters (500 acre-feet) shall be delivered to the United States upon demand at any time during the 12 month period commencing June 1st.

(iv) When the total natural flow of the Middle Fork Poplar, as determined below the confluence of Goose Creek, during the immediately preceding March 1st to May

31st period exceeds 14,8(X) cubic decameters (12,000 acres-feet) then a continuous minimum flow of 0.085 cubic metres per second (3.0 cubic feet per second) shall be delivered to the United States on the East Poplar River at the International Boundary during the succeeding period June 1st through August 31st. A minimum

delivery of 0.057 cubic metres per second (2.0 cubic feet per second) shall then be

maintained from September 1st through to May 31st of the following year. In

addition, a volume of 1,230 cubic decameters (1,0(X) acre-feet) shall be delivered

to the United States upon demand at any tune during the 12-month period

commencing June 1st.

(c) The natural flow at the International Boundary in each of the remaining individual

fributaries shall not be depleted by more than 60 percent of its namral flow.

The natural flow and division periods for apportionment purposes shall be determined,

unless otherwise specified, for periods of time commensurate with the uses and

requirements of both countries.

A3-3

ANNEX 4

METRIC CONVERSION FACTORS

A4-1
ac

ac-ft C*cm

cm* dam'

tehahm

hm'

l.gpm

in

kg

km

km*

L

L/s m

m»mVs mm

tonne

U.S. gpm

METRIC CONVERSION FACTORS

4,047 m' = 0.04047 ha

1.233.5 m' = 1.2335 dam*

5/9(F°-32)

0.3937 in.

0.155 in^

1,000 m' = 0.8107 ac-ft

28.3171 X lO'm'

10,000 m* = 2.471 ac

100 m = 328.08 ft IxlO'm'

0.0758 L/s

2.54 cm

2.20462 lb = 1.1 xlO-'tons

0.62137 miles

0.3861 mi^

0.3532 ft' = 0.21997 I. gal = 0.26420 U.S. gal

0.035 cfs = 13.193 l.gpm = 15.848 U.S. gpm

3.2808 ftm* = 10.7636 ft^

1,000 L = 35.3144 ft' = 219.97 I. gal= 264.2 U.S. gal

35.314 cfs

0.00328 ft

1 ,000 kg = 1 .1023 ton (short)

0.0631 L/s

For Air Samples ppm = 100 pphm = 1000 x (Molecular Weight of substance/24.45) mg/m'

A4-2