Panel Report

10.1 Baseline Data and Impact Assessment

Concerns were raised about certain baseline data which were inadequate or missing in the original EIS, and about the proposed monitoring program. Most of these concerns were, however, addressed in a satisfactory manner by Cogema in its responses to the panel's requests for additional information. [The Midwest Project Environmental Impact Statement, Additional Information, Cogema Resources Inc., February, 1996, Parts 4.1 and 4.4. The Midwest Project Environmental Impact Statement, Supplementary Information, Response to Department of Fisheries and Oceans Comments, Cogema Resources, Inc., May, 1996.] Cogema has also committed to completion of the gathering of all required additional baseline information prior to construction of the mine.

Information presented at public hearings suggested that fish may have survived in Mink Arm when it was incompletely drained during the test mine phase of operations. [L. Quarshie, Transcript of Midwest Public Hearings, Saskatoon, Saskatchewan, June 15, 1996, p. 66.] This information requires confirmation. If fish are present in Mink Arm, the proponent must collect baseline information on them. Because of its isolation from the rest of South McMahon Lake, the presence of a fish population in Mink Arm would offer an ideal situation for monitoring the impacts of mine water effluent on the biota. Potential impacts would not be masked by fish migrating in or out of the area. If no impacts could be detected on the health or population dynamics of the fish in Mink Arm, it is unlikely that such effects could be detected further downstream. This could influence how fish populations are monitored in the long term.

A similar comment is relevant to the McClean Lake site where mill effluent will be released into Sink Lake over a longer time. Sink Lake and the adjacent Vulture Lake, like Mink Arm, contain fish populations isolated from the rest of the watershed. Thus, fish in this area would also provide ideal populations to assess for the potential impacts of mill effluent. The panel was concerned to learn that the fish in Sink Lake were to be poisoned. If this is true, the rationale for this decision should be re-examined.

More emphasis should be placed on assessing impacts close to the point of effluent release, where one might anticipate maximum effects. If impacts cannot be detected where effects are likely to be greatest, there is little point in looking for more subtle effects farther away from the main point of release.

Even when monitoring takes place at the most sensitive location, it may not be possible to detect impacts, either because there are no impacts, or because there is little statistical power in the analyses.[Statistical power refers to the ability of a particular statistical test to detect a given change in a population.] A study may be unable to detect a change in a population because of small sample size and a large variation between samples. [R.M. Peterman, Statistical Power Analysis Can Improve Fisheries Research and Management. Canadian Journal of Fisheries and Aquatic Science 47, 1990, pp. 2-15.] Baseline and monitoring data should be subjected to power analysis at each sample site. As a general rule, it should be possible to detect a 50 per cent reduction in a population at each site with a high degree of power or probability (>95 per cent). If there is little chance of detecting such a magnitude of change, the sampling or monitoring programme should be modified. This may require taking a larger number of samples at each sample site. To compensate for increased costs, it may be necessary to decrease the number of sample sites or increase the time interval between samples. However, it is better to sample a few things well, than many things poorly.

Another area of concern about the proposed monitoring programme is the confusion about the purpose of monitoring aquatic macrophytes. According to Cogema:

A wide variation in aquatic macrophyte data have made it difficult to assess the impacts from operations. Problems associated with contamination of water are usually observed first and corrected prior to any evidence from macrophyte data. [The Midwest Project Environmental Impact Statement, Main Document, Cogema Resources Inc., August, 1996, Part 3, p. 171.]

Cogema, therefore, does not propose to monitor aquatic macrophytes although baseline data will be collected. We do not agree with this approach. The purpose of environmental effects monitoring is to assess the impacts of contaminant release and to determine contaminant loads and transfer coefficients for specific biota. It is then possible to assess the reliability of the models which have been used to predict environmental impacts. This cannot be done in the absence of monitoring. Aquatic macrophytes are important Valued Ecosystem Components and should not be ignored.

Where possible, the mine operators should monitor the same Valued Ecosystem Components as the government agencies are monitoring in their assessments of cumulative effects distant from the mines.

Finally, the proponent should reassess its method of monitoring sediments, as discussed in our McArthur River report. [D.G. Lee, J. Archibald and R. Neal, McArthur River Uranium Mine Project, Minister of Public Works and Government Services, February, 1997, p. 35.] In areas of compacted sediment, contaminants will accumulate at the surface by adsorption and by deposition of new sediment. Because deposition rates of new sediments would be very low, the impacts from the mine are likely to be observed only in the top 1-2 cm of the sediment. Cogema proposes to take sediment cores every three years and divide them into two strata: 0-5 cm, and 5-15 cm. The monitoring would be more useful if sediment samples, taken less frequently, were divided into 1 cm strata, particularly in the top 5 cm. Similar reasoning should be applied to the sampling of soils where contaminant inputs also occur at the surface.

10.2 Monitoring at the Midwest Site

Mink Arm, the recommended site for release of effluent from the water treatment plant, is separated from the rest of South McMahon Lake by an earth dam with a culvert near its top, as described in Section 6.2. Since it is possible that upsets could cause the quality of the water in Mink Arm to exceed Saskatchewan Surface Water Quality Objectives, controls should be placed on the culvert to allow for containment and gradual release of contaminated water, if necessary. Also, as described in Section 10.1, Mink Arm would provide a natural laboratory for the study of the effects of uranium mine effluent on fish, macrophytes and sediments. To make use of this opportunity, a monitoring program should be carefully designed, instituted well before mining starts again, and continued until after mining has ceased and concentrations of contaminants in the biota, water and sediments reach acceptable levels.

10.3 Monitoring of the JEB Tailings Management Facility

As described in Section 9.2, the proposed method for disposal of tailings from the McClean Lake mill involves placing them in the JEB pit, where it is predicted that they will consolidate until their permeability eventually becomes much less than that of the surrounding rock. If consolidation occurs as predicted, ground water would flow preferentially around the tailings, decreasing the risk of contamination of the surrounding lakes. However, evidence was presented which suggested that the source terms used in arriving at these predictions may not have been conservative. If this is so, Fox Lake, in particular, would be subjected to unacceptable impacts.

The premise for calculating the environmental impact was the source term for the concentration of arsenic in tailings porewater remains constant or is depleted. We believe that the premise, based on information that's available, is invalid.

R. Swider, Transcript of Supplementary Public Hearings for Midwest and Cigar Lake, La Ronge, Saskatchewan, August 28, 1997, p. 7.

If the JEB TMF is approved, these predictions would need to be confirmed by detailed field observations during the operating, decommissioning and postdecommissioning phases, as prescribed by the licensing procedures. The construction licence for the JEB tailings management facility required the operator to measure the characteristics, including the permeability, of the overburden and various layers of rock forming the pit wall. Similarly, the operating licence for the tailings management facility would prescribe how the tailings, groundwater, the water in the pond overlying the tailings, and the water collected in the drainage sump beneath the tailings would be monitored. Subsequently, the licence for the decommissioning phase would require the final consolidation of the tailings and restoration of the groundwater to be monitored. The proposed monitoring program for the various phases has been described by the proponent [The Midwest Project Environmental Impact Statement, Supplemental Information, Cogema Resources Inc., May, 1996, Part 6, Appendix 1, Section 3.3.] and the panel is confident that the regulatory agencies will enforce an appropriate monitoring program for the facility.

The main outstanding issue to be addressed is the length of time the facility should be monitored after the pumps are shut off and the water table is restored. Local people deserve to know that contaminants are being contained within the facility and to be assured that, in the long term, any leakage of contaminants will be mitigated before organisms are harmed. Since modelling predicts that it would take about 10,000 years for the maximum concentration of contaminants to reach the nearest water body, Fox Lake, monitoring would have to continue at some level for the foreseeable future. The only way in which the people of the region can be assured of environmental protection is to monitor the facility indefinitely; it is not possible to guarantee a walk-away, zero-risk storage facility. The details of the monitoring program, possible maintenance of the facility, and ability to respond to any contingencies will require careful thought and appropriate funding.

It is apparent that the environmental risks associated with uranium tailings disposal areas will require periodic monitoring for as long as can be foreseen. Although these monitoring programs need not be expensive, the idea that it might be possible in a few years to completely walk away from a site that contains millions of tonnes of material that is both toxic and radioactive is not realistic. Instead, provisions should be made for continual monitoring of all Saskatchewan tailings disposal areas, including the aboveground facilities at Eldorado, Lorado, Gunner, Cluff Lake, Key Lake and Rabbit Lake, as well as the underground excavations that will eventually be filled. The term "decommissioned", when used in connection with uranium tailings management facilities, describes a site that is left in a condition that will require only infrequent monitoring and the lowest possible amount of maintenance; it does not mean that the site can be abandoned and forgotten about.

Previous reports by this and other panels have called for perpetual monitoring of tailings disposal facilities, and during the hearings the possible meaning of the word "perpetual" was debated. Modelling predicts that the maximum concentration of contaminants emanating from the JEB TMF may not reach Fox Lake for about 10,000 years. It will, therefore, be necessary to keep an eye on this facility for a very long time -- longer than the recorded history of humankind. In response to this observation, we are recommending that mechanisms be established which will permit us and our immediate descendants to monitor the site. If it is found that contaminant migration is at acceptable levels and that secondary mineralization is occurring, future generations might decide that continued monitoring is no longer necessary or, if contaminant migration is at unacceptable levels, they might decide to apply mitigative measures using technology available to them at that time. The best that we can do at this time is to proceed in a way that we believe will provide protection of the environment in the long term, by arranging for monitoring for the foreseeable future.

An authority should be established to oversee the monitoring and maintenance of the tailings management facilities, in perpetuity. Dedicated financial resources should be made available to cover the cost of these operations, as well as possible contingencies. The authority, which should include residents of the Athabasca region, could be given the task of overseeing all decommissioned tailings management facilities in the region.

The panel envisions a system whereby decommissioning costs will be covered by financial guarantees, from the mining companies, that have been legislated by the federal and provincial governments (see Section 12.3). However, postdecommissioning costs for the perpetual maintenance and monitoring of tailings management facilities, as well as for dealing with any contingencies which might arise, will require a dedicated permanent fund as well as an authority to oversee these activities. The fund might be called the Uranium Mining Contingency Fund (see Section 12.4).

10.4 Pathways Modelling

The proponent presented a comprehensive program for predicting potential environmental impacts through modelling of conditions locally and regionally. Valued Ecosystem Components (VECs) were used as indicators of potential impacts on pathways modelling for human dose response assessment. However, Environment Canada expressed concern that current human dose modelling is not conservative, largely due to a substitution of southern foods for country foods. [Environment Canada, Prairie and Northern Region, Submission to the Midwest Project Public Hearings, Regina, Saskatchewan, June 10, 1996, p. 2.]

Dose calculations obtained from pathways models may be inaccurate because of errors in estimating the contaminant source terms or transfer coefficients used in the models. For example, in estimating the doses for humans, the models use the radionuclide concentrations in muscle meat of caribou or moose; however, northerners also consume large quantities of organ meats, such as liver and kidney, that have significantly higher radionuclide concentrations.

A more realistic dose assessment would incorporate conditions during active mining, as well as those present after decommissioning, and scenarios which would include ingestion of larger percentages of local country foods, including food-chain transfer coefficients obtained from local sources. [P. Thomas, Transcript of Midwest Public Hearings, Saskatoon, Saskatchewan, May 30, 1996, p. 87.] The pathways modelling should be repeated taking these concerns into consideration and the proponent should be required to commit to a program of continual assessment to ensure that the pathways model is current.

10.5 Cumulative Effects

Cumulative impacts have been assessed for two situations. First, regional cumulative effects due to all existing and proposed uranium mines have been assessed for humans residing at Wollaston Lake, Hatchet Lake and Black Lake. [The Midwest Project Environmental Impact Statement, Main Document, Cogema Resources Inc., August, 1995, Part 5.] The largest dose during mining operations was calculated for the Wollaston Lake receptor and was estimated to be approximately 1 per cent of the natural background radiation. A similar estimate has been made by the Cumulative Effects Monitoring Working Group (CEMWG). [T. Gates and L. Chamney, Uranium Mining Cumulative Effects Monitoring and Assessment, Submission to the Midwest Project Public Hearings, Regina, Saskatchewan, June 10, 1996.]

Secondly, Cogema has assessed the effects on humans living on the mine site after decommissioning, and obtaining much of their food and water from the local area. [The Midwest Project Environmental Impact Statement, Additional Information, Cogema Resources Inc., February, 1996, Part 4.6.] This considers the cumulative effects of the mining and milling operation on the local environment. Two locations were studied: South McMahon Lake at the Midwest site and Vulture Lake at the McClean Lake site. Peak doses are predicted to occur immediately after decommissioning and to decline slowly with time at both sites. The peak radiological dose predicted initially at South McMahon Lake is just over 1 per cent and, at Vulture Lake, is approximately 6 per cent of that received from natural background radiation. Estimates were revised to consider the situation where all of a person's food and water were obtained from the local area. [The Midwest Project Environmental Impact Statement, Supplementary Information - Response to Environment Canada Review Comments, Cogema Resources Inc., May, 1996, p. 5.] This increased the doses by, at most, a quarter of the original estimates. Consequently, it may be concluded that the potential radiological impact of the Midwest and McClean Lake developments is acceptably low. There is, however, a potential for arsenic to be an unacceptable risk to human health at the Vulture Lake site. If field observations of water and sediment concentrations of arsenic or any other contaminants at Vulture Lake are unacceptable, remedial action would be required.

All predictions need to be confirmed by the use of a well-defined monitoring program. Saskatchewan Environment and Resource Management (SERM) and the Atomic Energy Control Board (AECB) agreed to establish such a program [The Atomic Energy Control Board, Memo to Board Members from the Directorate of Fuel Cycle and Materials Regulation, May 10, 1994.] in response to an earlier recommendation of the panel. [D.G. Lee, J.F. Archibald, J. Dantouze, R. Neal and A. Yassi, Dominique-Janine Extension, McClean Lake Project, and Midwest Joint Venture, Supply and Services Canada, October, 1993, p. 16.] They formed a working group (the CEMWG, noted previously) in 1994 with technical advice from representatives of Saskatchewan Health, Environment Canada, Department of Fisheries and Oceans Canada, Saskatchewan Research Council, University of Saskatchewan Toxicology Centre, Canadian Cooperative Wildlife Health Centre, Saskatchewan Northern Mines Monitoring Secretariat, and Terrestrial and Aquatic Environmental Managers Ltd. (TAEM). [T. Gates and L. Chamney, Uranium Mining Cumulative Effects Monitoring and Assessment, Submission to the Midwest Project Public Hearings, Regina, Saskatchewan, June 10, 1996.] This working group continues to improve the IMPACT/AECB model, which evaluates cumulative environmental effects. It has also established a cumulative effects monitoring program for all of the mines to test the reliability of the model's predictions using field observations. A total of 63 sample stations have been established. Valued ecosystem components to be monitored on a 3-year cycle include air, soil, lichen, blueberry, spruce needles, caribou, spruce grouse, water, depositional sediments, macrophytes, benthos, and fish. Each VEC is assessed for concentrations of radionuclides and metals, as well as other physical and chemical parameters. The panel endorses this initiative and notes that it should reassure Athabasca residents and other northerners about the safety of country foods, particularly if the residents are involved in the collection of this information and have representation on the monitoring committees (see Sections 11.2 and 11.3).

...I think that you'll gain public trust by involving people in that monitoring...

P. Thomas, Transcript of Midwest Public Hearings, Saskatoon, Saskatchewan, May 30, 1996, p. 94

10.6 Conclusions and Recommendations

The presence of isolated populations of fish in Mink Arm, Sink Lake, and Vulture Lake provides an opportunity to study the effect of uranium mining and milling on fish. Aquatic macrophytes and sediments should also be studied.

Modelling results indicate that the environmental impacts of this project may not be within acceptable limits. There is a potential for arsenic to be an unacceptable health risk at Vulture Lake and Fox Lake. Therefore, careful monitoring using actual field observations, combined with appropriate mitigation, will be required to ensure that the environment is protected and that the decommissioned site will not present unacceptable risks to human health.

Monitoring will be required over a much longer time span than that suggested in the Environmental Impact Statement; the JEB tailings management facility, if approved, would require perpetual monitoring.

Local residents should be involved in all monitoring activities.