Independent Environmental Monitoring Program: Key Lake Operation

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[ ] Guideline/Reference Level

2021 Results

The 2021 IEMP sampling plan for the Key Lake Operation focused on radioactive and hazardous substances (e.g., metals). A site-specific sampling plan was developed based on the licensee’s approved environmental monitoring program and our regulatory experience with the site. We endeavour to incorporate traditional Indigenous land use, values and knowledge by engaging with Indigenous Nations and communities on the sampling plan. More information on this engagement is provided in the “Indigenous Nations and communities’ participation” section.

In August 2021, CanNorth collected surface water at a reference station (David Lake) not exposed to the activities of the Key Lake Operation and at 3 exposure stations (David Creek, Delta Lake, and Wheeler River Bridge on highway 914). Fish (lake whitefish, white sucker and northern pike), blueberries and Labrador tea samples were also collected at David Lake and at Wheeler River Bridge. In addition, hunters from the English River First Nation (ERFN) collected 2 moose samples: one at the road between the Key Lake Operation and the McArthur River Operation at around the 63 km marker, and one at highway 914 approximately 62 km north of Pinehouse. All sampling locations were outside the Key Lake Operation site perimeter. These samples were sent to the SRC laboratories for testing and analysis.

Radioactivity levels (radiological contaminants) and concentrations of hazardous contaminants in surface-water samples were within natural background levels ^{Footnote 1} and, for the most part, below the Canadian Council of Ministers of the Environment (CCME) guidelines for the protection of aquatic life ^{Footnote 1} and the Province of Saskatchewan’s drinking water quality standards and objectives ^{Footnote 3}. Therefore, the surface water is safe to drink relative to the parameters analyzed.

Although the pH levels and ammonia in 3 of the samples were outside the CCME guidelines, they were within the known regional background levels. The pH in this area is naturally low, which is attributed to natural acid-generating conditions. There is no concern for the environment or human health at these levels.

For radiological contaminants in fish, Labrador tea, blueberries and moose, CNSC staff compared monitoring results to CNSC screening levels to ensure that human health is protected. CNSC screening levels were calculated based on conservative assumptions about ingestion of food and outdoor exposure, using CSA standard N288.1-14 ^{Footnote 4} and International Commission on Radiological Protection (ICRP) Publication 119 ^{Footnote 5}. The screening level for each radionuclide in a particular medium (e.g., fish, Labrador tea, berries) represents the radioactivity level that would result in a dose of 0.1 mSv/ year (millisieverts per year), or one tenth of the CNSC regulatory dose limit for a member of the public of 1 mSv/year ^{Footnote 6}. The approach used by CNSC staff to calculate screening levels is similar to the Health Canada and World Health Organization approach for drinking water guidelines ^{Footnote 7 Footnote 8}, where 0.1 mSv/year is also used.

With the exception of polonium-210 in fish and in moose, both of which are discussed below, the measured radioactivity levels for all radiological contaminants in fish, Labrador tea, blueberries and moose were below the CNSC screening levels for radionuclides.

The measured radioactivity levels of polonium-210 in fish at both the exposure and reference stations were within the regional background range of 0.02 to 14 Bq/kg (becquerels per kilogram) fresh weight ^{Footnote 1}, and were consistent with the results from the Eastern Athabasca Regional Monitoring Program (EARMP) for the northern Saskatchewan region ^{Footnote 9}. The highest radioactivity level of polonium‑210 in fish analyzed in the Key Lake Operation study area was 3.5 Bq/kg fresh weight in a northern pike sample caught at the David Lake reference station. This level of polonium-210 is within the natural background range, bearing in mind that, by definition, a reference station is not affected by a facility’s operations. The results also show that radioactivity levels of polonium-210 in fish in the Wheeler River Bridge exposure area were not the result of the Key Lake Operation since they were similar to the levels detected at the reference station (David Lake). This means that they are attributable to natural background radioactivity levels for the region.

Consumption of fish is not expected to result in any adverse health effects from polonium-210 given the conservative nature of the screening levels and given that the radioactivity levels for all other samples analyzed (water, Labrador tea, blueberries and moose) were well below CNSC screening levels. The screening levels are conservative because they are based on an individual receiving a dose of 0.1 mSv/yr.

As a result, the consumption of water, fish, Labrador tea, blueberries or moose is not expected to result in any adverse health effects from radiological contaminants. CNSC staff’s assessment of the moose results is provided in the last paragraph of this section.

CNSC screening levels were also calculated for hazardous contaminants. The CNSC screening level represents the concentration required for a representative person (adult or child) to ingest one tenth of Health Canada's tolerable daily intake (TDI) of a hazardous contaminant from multiple food ingestion pathways, such as drinking water, fruit, vegetables and fish/meat. This adds conservatism to the assessment because it considers that the receptor could be exposed to a contaminant through 10 different exposure pathways. It is likely that only 1 or 2 pathways are predominant; however, the CNSC’s assessment takes into account all 10. A TDI is the concentration of a hazardous contaminant that is safe for daily ingestion by humans on a long‑term basis. The CNSC screening levels developed for the Key Lake Operation IEMP sampling campaign are conservative and are calculated using ingestion rates for a regional Indigenous diet.

With the exception of selenium in fish and zinc in moose, both of which are discussed below, the concentration of hazardous contaminants in fish, blueberries, Labrador tea and moose were below CNSC screening levels for hazardous substances.

The regional background concentration of selenium in fish ranges from 0.12 to 3.03 mg/kg (milligrams per kilogram) fresh weight ^{Footnote 1}. The concentration of selenium in northern pike ranged from 0.11 to 0.14 mg/kg fresh weight at the David Lake reference station and from 0.34 to 0.39 mg/kg fresh weight at the Wheeler River Bridge exposure station. The highest concentrations of selenium in lake whitefish and white sucker were 0.17 and 0.34 mg/kg fresh weight at David Lake (reference station) and at Wheeler River Bridge (exposure station) respectively. The measured concentrations of selenium in fish at both the exposure and reference stations were within the regional background concentration range. The results also show that concentrations of selenium in fish in the exposure area of Wheeler River Bridge were not the result of the Key Lake Operation since they were similar to the levels detected at the reference station (David Lake). This means that they are attributable to natural background selenium levels for the region. The results are also consistent with the results from the EARMP for the northern Saskatchewan region ^{Footnote 9}.

The highest concentration of selenium in fish analyzed in the Key Lake Operation study area was 0.39 mg/kg fresh weight in a lake whitefish sample, caught at the Wheeler River Bridge exposure station. A concentration of 0.39 mg/kg fresh weight in fish is 18% of the selenium TDI of 2.17 mg/kg fresh weight. The selenium contribution from other ingestion pathways, including water, blueberries and Labrador tea, was negligible. No health effects are expected from the consumption of fish due to selenium. This is because the highest concentration of selenium in fish was less than half of the conservative CNSC screening level, and the selenium concentrations in all other samples analyzed (water, Labrador tea, blueberries) were well below the screening level.

For context, the selenium concentrations in fish tissue on a dry weight basis are below the United States Environmental Protection Agency’s 2016 selenium criterion for fish muscle tissue of 11.3 mg/kg dry weight. This indicates that the fish are not affected by selenium.

Since there were exceedances of the zinc and polonium-210 screening levels in moose tissue, CNSC staff compared the IEMP moose results with moose results collected from other studies conducted in northern Saskatchewan, such as the ERFN Food, Nutrition & Environment Study and the EARMP ^{Footnote 9}. CNSC staff concluded that the IEMP moose results are typical of other moose samples taken to date from various areas in the boreal forest in Saskatchewan and elsewhere in the province that are not located near a uranium mine or mill. Therefore, no health impacts are expected and the moose is safe to eat.

2014 Results

The 2014 IEMP sampling plan for the Key Lake Operation focused on both radiological (nuclear) and non-radiological (hazardous) contaminants. A site-specific sampling plan was developed based on Cameco’s approved environmental monitoring program, CSA Group standards and the CNSC’s regulatory experience with the site. In 2014, water samples were collected at three sites downstream of the effluent discharge point, and at a one background location upstream for comparison. All samples were taken outside the Key Lake Operation site perimeter.

View detailed sampling data.

The measured radioactivity in the samples were below drinking water quality guidelines. No health impacts are expected at these levels.

With respect to the non-radiological analysis, the concentrations of analyzed substances in water were mostly below or close to the Canadian Council of Ministers of the Environment’s (CCME) guidelines and within the natural background levels.

The pH levels in three of the samples were slightly below the CCME guidelines, however they were within known regional background levels. The pH in this area is naturally low which is attributed to naturally acid generating conditions. There is no concern to the environment or to human health at these levels.

Selenium and molybdenum are two contaminants released as part of the regular milling process and are analyzed as part of the IEMP. In 2014, two water samples had molybdenum concentrations that exceeded the CCME guideline, and one water sample exceeded the CCME guideline for selenium. The results of the samples taken close to the effluent discharge point were consistent with Cameco’s environmental monitoring program results. No health impacts are expected at the current levels.

Selenium and molybdenum have received CNSC regulatory focus since the NSCA came into force in 2000. Over recent years, the CNSC has identified the need for improved water treatment systems for a few hazardous substances at some of the operating mines, including the Key Lake Operation. Cameco’s environmental monitoring program has demonstrated that selenium and molybdenum water concentrations have decreased significantly since the installation of effluent treatment system upgrades in 2009. The CNSC expects that the surface water quality will continue to improve in the future at the Key Lake Operation.

To obtain the full technical IEMP report, contact us at cnsc.info.ccsn@cnsc-ccsn.gc.ca or call 613-995-5894 or 1-800-668-5284 (in Canada). Please provide the name of the facility and the report year.

Indigenous Nations and communities’ participation

We have made it a priority to ensure that IEMP sampling reflects Indigenous traditional knowledge, land use and values where possible. In addition to routine IEMP sampling activities, we seek input from local Indigenous Nations and communities on our IEMP sampling plans.

In advance of the 2021 IEMP sampling campaign at the Key Lake Operation, notification emails were sent to Indigenous Nations and communities near the facility to notify them of the campaign and to seek input on the sampling plan. We invited suggestions for species of interest, valued components, and potential sampling locations where traditional practices and activities may take place.

CNSC staff sent the draft IEMP sampling plan to and held teleconferences with ERFN to gather feedback. As part of their review process, ERFN shared the draft IEMP sampling plan with community Elders, Leadership and Land Users. ERFN reviewed the draft sampling plan and concluded that the sampling locations and sampling media were acceptable. In their review, ERFN indicated that their community members frequently gather moose at locations between the Key Lake and McArthur River operations. As a result, ERFN suggested to the CNSC that moose samples be included in the IEMP. CNSC staff incorporated 2 moose samples into the final sampling plan. CNSC staff will continue to engage with ERFN on the Key Lake Operation.

We will continue to engage with interested Indigenous Nations and communities to ensure that the IEMP incorporates Indigenous knowledge in future sampling.

View detailed sampling data.

Conclusions

Our IEMP results from 2021 and 2014 (last IEMP campaign in the vicinity of the Key Lake Operation) are consistent with the results submitted by Cameco, supporting our assessment that the licensee’s environmental protection program is effective. The results add to the body of evidence that people and the environment in the vicinity of the Key Lake Operation are protected and that there are no anticipated health impacts from the operation of the facilities on the site.