Environmental Performance of a Uranium Mine or Mill Regulated Under the Nuclear Safety and Control Act

Transcription

1 Environmental Performance of a Uranium Mine or Mill Regulated Under the Nuclear Safety and Control Act Based on Environmental Data Associated with Operating Uranium Mines and Mills (2000 Prepared by: Canadian Nuclear Safety Commission for the Quebec BAPE Hearings on Uranium Industry Issues in Quebec October, 2014 e-doc (Word) e-doc (PDF)

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3 Introduction EXECUTIVE SUMMARY The Canadian Nuclear Safety Commission (CNSC) regulates the development, production and use of nuclear energy and the production, possession and use of nuclear substances, prescribed equipment and prescribed information in order to prevent unreasonable risk to the environment and the health and safety of persons. The CNSC has a rigorous environmental protection framework that is based on: Regulatory Instruments: legislation, licenses, standards and regulatory documents. Licensing and environmental protection policies, programs and procedures. Compliance verification to ensure that licensees comply with requirements. Regulatory support through the conduct of research, risk assessment and performance assessment. There is extensive natural background and receiving environment monitoring data collected at the northern Saskatchewan uranium mining operations to meet the requirements of this environmental protection framework. The CNSC has assembled a comprehensive database containing the core environmental chemistry (both nuclear and hazardous substances) monitoring results at operating uranium mines and mills since the Nuclear Safety and Control Act (NSCA) came into force in This report provides a summary of the data and is being made available to support the CNSC s commitment to regulatory transparency and its mandate to disseminate objective scientific information. The report covers 13 years of data collection (2000 to addressing 22 contaminants of potential concern (COPC). These COPCs have been identified for routine monitoring through environmental risk assessments (ERA) which are required by the CNSC for all uranium mining and milling operations. Environmental Performance for a Modern Uranium Mine/Mill For this report, the monitoring data from four operating northern Saskatchewan uranium mining and/or milling sites have been incorporated into one database, thereby capturing a range of site-specific environmental factors. The focus is on the core monitoring elements common to all the operating uranium mines and mills; air, surface water, fish and aquatic sediments. Mean concentrations of nuclear and hazardous substances are presented relative to their distance from their primary source of release to the environment. The concentrations were compared to applicable guidelines and criteria for the protection of human health and the environment (e.g., Canadian Environmental Quality Guidelines, Province of Saskatchewan Drinking Water Standards and Objectives), and the CNSC public dose 1 Environmental protection programs pre-date the NSCA (i.e., to meet requirements of the province and the federal Atomic Energy Control Act, predecessor of the NSCA). The NSCA enhanced and formalized environmental protection responsibilities of the federal nuclear regulator. 2

4 limit of 1 msv per year above natural background radiation. Measured concentrations were also compared to the range of natural background concentrations from the region. Recent environmental monitoring data from existing uranium mining and/or milling operations for off-site concentrations (more than 2 km from the source) reflect what one could expect at a modern operating high grade ore uranium mine or mill regulated by the CNSC under the NSCA. A proposal for a new uranium mine and/or mill would nevertheless be required to address all site-specific facility and local human and environmental factors as part of the CNSC regulatory process. Findings The compilation of air monitoring data from the past 13 years demonstrates that a modern operation would meet ambient air quality criteria for hazardous substances, meaning both onsite workers and the public would be protected. Similarly, air particulate radionuclide concentrations would not pose a risk to the public as levels would be expected to be below reference doses (0.1 msv per year, one-tenth the CNSC public dose limit). Radon concentrations in air are demonstrated to rapidly decrease with distance from source. At a mine site lease boundary distance (i.e., approximating > 2 km from source), exposure of the public to radon is similar to natural background. Liquid effluent releases to surface water are the most significant source of contaminants to the environment from an operating facility. Treated mine and/or mill effluent is managed to ensure that drinking water supplies are protected and not at risk. The compiled surface water monitoring data demonstrate that drinking water guidelines for radionuclides are achieved within the immediate receiving environment with all other health drinking water guidelines being achieved at all stations beyond an assumed 2 km surface lease boundary. The consumption of fish from effluent receiving surface waters is also an important human exposure pathway. Five contaminants of potential concern (COPC) have the potential to accumulate in fish flesh above natural background concentrations; though levels are well-below typical human health consumption guidelines. The monitoring data demonstrated that without specific effluent controls, selenium can accumulate within fish flesh, such that the human consumption health guideline could be exceeded in sensitive receiving environments when high human fish consumption rates are assumed. The CNSC has required treatment of selenium in effluent for existing uranium mills where necessary. Many forms of aquatic life are more sensitive to contaminants than humans. If effluent releases are not properly managed, they may pose a risk to aquatic life. The extensive water quality monitoring downstream of modern uranium mines and mills indicates that uranium, molybdenum and selenium, if untreated, posed the greatest potential for offsite (assumed 2 km radius from source) impacts on water. Uranium, selenium and molybdenum, arsenic and nickel concentrations in aquatic sediments were also greater than natural background concentrations and greater than sediment quality guidelines for the protection of aquatic life beyond 2 km from a source. Accumulation of COPCs in the sediments is at least partly responsible for changes in the sediment dwelling benthic invertebrate communities observed in some near-field effluent receiving water bodies. 3

5 These changes were predicted in the original environmental risk assessments and accepted as not representing significant adverse effects. The NSCA formally expanded the environmental protection mandate of the federal nuclear regulator to include hazardous substances as well nuclear substances. The resultant increased technical over-sight of hazardous substances identified three COPCs (uranium, molybdenum and selenium) as meriting increased regulatory attention. Licensees were required to implement treatment system upgrades to reduce the release of these COPCs to the aquatic environment. Surface water quality data collected since the installation of treatment system upgrades have demonstrated that uranium and molybdenum releases have been addressed. They should not pose an environmental risk at any future uranium mine or mill designed to meet present day expectations of the CNSC. Selenium releases continue to require careful management as specific types of aquatic eco-systems are now known to be sensitive to this substance. Any future uranium mine and or mill will need to incorporate effluent treatment systems which adequately address selenium risk to sensitive receiving environments if they are to receive CNSC regulatory approval. The two most recent proposals for new mines in Saskatchewan have both included a reverse osmosis circuit to further augment the performance of their proposed water treatment systems. This provides additional treatment for all the COPCs (nuclear and hazardous substances) associated with uranium mining This review of the receiving environment monitoring programs associated with the existing uranium mines and mills demonstrates that a uranium mine or mill regulated by the CNSC can be operated in a manner that protects both public health and the environment. 4

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7 TABLE OF CONTENTS EXECUTIVE SUMMARY INTRODUCTION Environmental Performance for a Modern Uranium Mine/Mill METHODS Contaminants of Potential Concern Data Statistical Analysis Time Period for Statistical Analyses RESULTS Ambient Air Quality Ambient Air Particulate Monitoring Hazardous Substances Nuclear Substances Radon Aquatic Environment Surface Water Monitoring of COPCs in Fish Flesh Sediment Quality CONCLUSION REFERENCES ACRONYMS APPENDIX A AIR QUALITY Sample Calculations Ambient Air Quality Sample Calculation of Reference Annual Air Quality Reference Levels for Hazardous Substances Sample Calculation of Air Quality Reference Levels for Nuclear Substances Sample Calculation for the Conversion of the Uranium from µg/m 3 to Bq/m Sample Calculation for combined dose for all measured radionuclide from the high volume ambient air samplers References Air Quality Summary and Reference Value Tables

8 Appendix B Surface Water Quality Surface Water Quality Summary Tables Surface Water Quality Figures APPENDIX C CONCENTRATION IN FISH FLESH Sample Calculations Concentrations in Fish Flesh Sample Calculations Fish Toxicity Reference Values Sample Calculations Nuclear Substances Reference Fish Concentrations References Concentration in Fish Flesh Summary Tables Concentration in Fish Flesh Figures APPENDIX D SEDIMENT QUALITY Sediment Quality Summary Tables Sediment Quality Figures

9 1 INTRODUCTION The CNSC regulates the development, production and use of nuclear energy and the production, possession and use of nuclear substances, prescribed equipment and prescribed information in order to protect the health and safety of persons and the environment. This is done through a rigorous environmental protection framework that is based on: Regulatory Instruments: legislation, licenses, standards and regulatory documents. Licensing and environmental protection policies, programs and procedures. Compliance verification to ensure that licensees comply with requirements. Regulatory support through the conduct of research, risk assessment and performance assessment. In June 2000, the CNSC was given an explicit mandate in environmental protection that included the regulation of both nuclear and hazardous substances under the Nuclear Safety and Control Act (NSCA). Both effluent and receiving environment monitoring programs are required for all uranium mines and mills. They are designed to meet specified regulatory requirements as well as address facility specific issues identified in the site-specific ERA (see CNSC 2014a). The objective of these programs is to demonstrate that regulatory requirements have been met; and that all reasonable precautions have been taken to control releases and hence prevent unreasonable risk to the public and the environment. As a result, there is a wealth of natural background and exposure environmental monitoring data associated with the northern Saskatchewan uranium mining operations. Thus, in accordance with the CNSC s commitment to regulatory transparency and its mandate to disseminate objective scientific information, the CNSC has assembled a comprehensive database containing the core environmental chemistry (both nuclear and hazardous substances) monitoring results at operating uranium mines and mills since the coming into force of the NSCA 2. This report covers 13 years of data collection from 2000 to 2012 and includes information collected by licensees for 22 contaminants of potential concern (COPC). These COPCs have been identified for routine monitoring through ERAs which are required by the CNSC for all uranium mining and milling operations. 2 Note: the completion of environmental assessments incorporating environmental and human health risk assessments and the design and implementation of receiving environment monitoring programs pre-dates the NSCA The Joint Federal-Provincial Panels on Uranium Mining and Milling Developments in Northern Saskatchewan of the 1990s involving the province and the Atomic Energy Control Board (predecessor of the CNSCC) established comprehensive monitoring requirements carried forward into both federal and provincial licensing activities. The NSCA modernized and formalized environmental protection requirements for the federal nuclear regulator. 8

10 1.1 Environmental Performance for a Modern Uranium Mine/Mill Uranium mine and milling operations are required to design, implement, interpret and maintain extensive environmental monitoring programs. CNSC document entitled Environmental Protection Framework for Operating Uranium Mines and Mills Under the Nuclear Safety and Control Act (CNSC 2014a) provides an introduction to the CNSC environmental protection framework and the monitoring programs associated with uranium mines and mills in Canada. This document focuses on the core monitoring elements common to all the operating uranium mines and mills: air, surface water, fish and aquatic sediments for which there are national and/or provincial environmental quality criteria. Existing uranium mine/mill monitoring programs also contain additional monitoring elements as indicted by their site-specific ERA, to support environmental risk assessment modelling and test ERA predictions, but have not been summarized here (e.g., lichen, country foods, wildlife). Uranium mines and mills are also required to complete Environmental Effects Monitoring Programs, (chronic toxicity testing, benthic macroinvertebrate community monitoring and fish health/population assessments) to meet the environmental effects monitoring (EEM) requirements of both the NSCA and the federal Metal Mining Effluent Regulations (MMER). CNSC environmental specialists work jointly with Environment Canada to ensure that these programs not only meet but exceed MMER requirements. The latest Environment Canada analyses of the national EEM program, which include the uranium mining sector was published in 2012 (Environment Canada. These data provide the information required to ensure that operations remain within the licensing basis as approved by the Commission and identified within the CNSC licence. Licensees are expected to maintain continuous oversight and management of their environmental impacts. CNSC licensing and specialist staff, through the compliance and verification programs, assesses the adequacy of a facility s environmental performance with respect to the requirements of the NSCA and the license. In addition to the site specific programs, the Saskatchewan Government s Eastern Athabasca Regional Monitoring Program (EARMP) monitors the environment and country foods associated with the Athabasca Basin communities in closest proximity to the mining and milling operations. The EARMP community based program monitors the safety of traditionally harvested country foods through the testing of water, fish, berry and mammal (moose/caribou) chemistry for COPCs associated with uranium mining. The reports and additional information on the EARMP program can be found at the following web site EAs completed under the NSCA and the CEAA contain a wealth of diverse data on environmental performance 3. Many ERAs have also been performed for existing and proposed projects to interpret these data and to make projections for future environmental performance. These documents are reviewed by CNSC technical specialists to ensure appropriate technical and scientific methods are used. 3 See 9

11 These documents, by their very nature, are site-specific as each project must be assessed on its own merits. This makes it difficult to address requests with respect to the environmental effects that one could expect from a theoretical modern uranium mine. For example, concerns are often expressed with respect to the spatial extent of contaminant dispersion within an effluent receiving watershed. This can be influenced by site-specific facility characteristics (e.g., ore mineralogy, mining and milling methods) and environmental characteristics (e.g., water volume, retention time and/or detrital and biological composition of the receiving waters and their associated sediment). Similarly, human exposure is related to the proximity of the nearest human receptor and their lifestyle characteristics. How then does one present the potential distribution of potential contaminants for a non-specific theoretical operation? This is addressed in this report by combining the results of the monitoring data from the existing mine/milling sites into one database, thereby capturing a range of facility and site-specific environmental factors. Specifically, relevant data were tabulated by the monitoring station distance from primary facility release points to air or surface water for four operating uranium mines and mills in northern Saskatchewan: the Rabbit Mine and Mill; the Mine and Mill; the Mine and Mill and the McArthur River Mine. The time period addressed within this assessment extends from 2000 to 2012, inclusive. This time period was selected as it encompasses the coming into-force of the modern uranium mining and milling regulations associated with the NSCA up to present time. It is important to note that the mines/mills involved in this assessment commenced operations prior to the NSCA (i.e., 2000). Two of the operations extend back to the late 1970s/early 1980s (Rabbit and ) with substantial improvements occurring in environmental protection practices, technologies and regulatory over-site occurring over this time. Some of the existing environmental conditions reflect these older practices. The two more recent operations commenced in the late 1990s (McArthur River and ). Thus these results represent a conservative range (i.e., over predict releases to and quantities in the environment) of performance one might expect from modern mines/mills operating in high precipitation boreal environments exploiting high grade ore. A short description of each facility is provided in the CNSC document on the environmental protection framework for uranium mines/mills (CNSC 2014a). Actual measured levels (average and upper bound) of nuclear and hazardous substances are presented relative to their distance from their primary point of release to the environment. These measured levels (background and exposure) were compared to applicable guidelines and criteria for the protection of human health and the environment (e.g., Canadian Environmental Quality and Guidelines, drinking water guidelines, and the CNSC public dose limit of 1 msv per year above natural background radiation) as well as to the range of conditions in reference areas from this mining region. Where concentrations exceeded guidelines beyond 2 km from effluent release points (a representative boundary for the edge of a licensed facility), values have been compared for two time periods: and The data for reflect improvements in effluent treatment technologies required by the CNSC. The improvements occurred after follow-up risk assessments indicated that additional effluent 10

12 treatment was merited for specific substances not explicitly regulated by effluent release limits under federal MMER (i.e., uranium, selenium, molybdenum). 2 METHODS 2.1 Contaminants of Potential Concern The nuclear and hazardous substances presented here were selected based on the existing environmental legislation for metal mining (MMER) as well as those consistently identified as being of potential concern in site-specific risk assessments conducted to support licensing requirements under the NSCA. The MMER require all mines to report arsenic, copper, cyanide, lead, nickel, zinc, total suspended solids (TSS), radium-226 and ph in effluent. Cyanide which is generally associated with gold mining is not used in uranium mining and/or milling and therefore there is no requirement for CNSC licensees to monitor it at uranium mines and mills. The CNSC requires monitoring and reporting of contaminants in addition to the MMER requirements. These additional substances are required to: characterize the natural uranium series decay chain (radon, lead-210, polonium-210, thorium-230) address specific COPCs identified in site-specific ERAs (e.g., U, Mo, Se) ensure that full characterization of effluents and their presence in the environment is completed (e.g., Cd, Co, Fe, Mg, V, etc.) respond to issues of public concern Contaminants monitored in exposure pathways can vary from site to site. This is due to site-specific differences in mining and milling processes and the nature of the surrounding environment. Table 1 summarizes the most common nuclear and hazardous substances monitored in the receiving environment at uranium mines and mills in Canada. It should be noted that within this document uranium is presented as both a hazardous substances (mass/unit volume: e.g., mg/l) to address chemical toxicity, and as a nuclear substances (activity level/unit volume: e.g., Bq/L) to address radiological dose. However, as uranium is more chemically than radiologically toxic, it is most commonly presented in association with the other hazardous substances (US ATSDR 2013). Table 1: Nuclear and hazardous substances monitored at uranium mines and mills in Canada Exposure pathway Air Nuclear or hazardous substances monitored Th-230, Ra-226, Pb- Nuclear 210, Po-210, Rn As, Cd, Pb, Ni, U, Hazardous Se, Cu, Mo Zn Annual reports Source 1 Status of the environment reports 11

13 Exposure pathway Water Sediment Fish Nuclear or hazardous substances monitored Nuclear Hazardous Nuclear Hazardous Nuclear Hazardous Ra-226, Pb-210, Th- 230, Po-210 ph, NH3, TSS, P, Al, As, Ba, B, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, Zn, U Ra-226, Pb-210, Th- 230, Po-210 Al, As, Ba, B, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, Zn, U Ra-226, Pb-210, Th- 230, Po-210 Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, Zn, U Annual reports Source 1 Status of the environment reports Environmental effects Monitoring reports Annual reports Status of the environment reports Environmental effects Monitoring reports Annual Reports Status of the Environment Reports Environmental Effects Monitoring Reports Soil Nuclear Hazardous Ra-226, Pb-210, Th- 230, Po-210 ph, Al, As, Cd, Co, Cu, Fe, Mo, Ni, Pb, Se, V, Zn, U Annual reports Status of the environment reports 1 These reports are submitted to provincial and federal regulators. CNSC licensing and specialist staff complete technical reviews as part of the CNSC environmental compliance program. 2.2 Data Environmental monitoring data (air, surface water, fish and sediment) for a 13-year time period (2000 at four Canadian uranium mines and mills were compiled. Soil data were not included in this compendium as levels are low, and this pathway is largely captured through particulate air sampling. The data were collected (monthly, quarterly or annually) as a licence requirement and submitted to the CNSC for regulatory review. The sources of data were annual reports, status of the environment reports and environmental effects monitoring reports. All data were subject to quality assurance and quality control (QA/QC) practices for sample collection and laboratory analysis. The distance of each monitoring station from the point of release (atmospheric or aquatic) was determined by measuring the direct linear distance of each station from the nearest 12

14 release point. The distance reported is not necessarily the distance through the relevant discharge channel unless noted otherwise. s that are downwind or downstream of atmospheric or effluent release points are considered exposure sites. Background monitoring sites are stations that represent typical background or existing conditions in the area. The use of graphs was selected as an easily interpretable approach for presenting the data. A generic example is shown in Figure 1. Each data point in the figure represents the measured average concentration (± 1 Standard Error) of the COPC at a given distance from the nearest source for that COPC. The green filled area represents the measured background range for the specific COPC. Note that many of the COPCs are present at relatively low levels; hence the background range in many of the figures is shown to extend to zero. Available environmental quality criteria for the COPC are provided as horizontal lines. These criteria may be provincial or federal environmental quality criteria or exposure reference levels calculated for this report. The exposure reference levels are explained whenever they are presented. In these figures the 2 km (linear) distance from the nearest point of release is indicated by a vertical line. This distance was selected as a means of generically representing onsite monitoring (0 2 km) from offsite monitoring (> 2 km). A 2 km radius circle from a release point was considered to represent a distance from which one would reasonably be expected to be within the onsite footprint of a mine site. A review of the surface area of the lease boundaries of the facilities included in this assessment supports this as being a conservative assumption. The surface lease boundaries for the four mines and/or mills in this assessment range from 1425 ha to 3677 ha. A circle with a radius of 2 km corresponds to 1256 ha, which is less than the smallest surface lease of the four sites included in this work. The 2 km boundary was not considered for air quality data as nearly all monitoring stations were within the site footprint. 13

15 Figure 1: Generic representation of graphical data Onsite 40 Guideline Concentration or Activity Level Reference + 2 Standard Deviations Distance from the source (km) The dataset presented in the appendices contains one extremely far-field station (~ 37.5 km, Russell ) which was consistently removed from figures so that the data for stations at 0 15 km from the effluent discharge points could be displayed at better resolution. The removal of this station does not influence interpretations as COPCs were at or within background levels at this distance. 2.3 Statistical Analysis The data compiled from original reports were carefully scrutinized before statistics were calculated. All negatives, zeroes, non-detects, not applicable and blank sample entries were removed. Entries reported as being less than the analytical detection limit were given a value of half the detection limit except for radon where entries were left at the detection limit. Concentrations were also converted to the common units identified in for each environmental pathway (see table 2). 14

16 Table 2: Units used in the analyses and presentation of the datasets Environmental Hazardous substances Nuclear substances Wet or dry weight pathway Air µg/m 3 Bq/m 3 n/a Water mg/l Bq/L n/a Fish mg/kg Bq/kg Fresh weight Sediment mg/kg Bq/kg Dry weight The data for each exposure pathway was treated as follows prior to calculating statistics: Air quality for nuclear and hazardous substances was determined using high volume ambient air samplers. Annual means were calculated from monthly and/or quarterly data depending on the station. Summary statistics were derived for the entire 13-year dataset (2000 at each of the monitoring stations. Radon (air quality): Radon monitoring was completed using passive track etch devices left in place for a minimum of three months to a maximum of one year to ensure adequate time to obtain results in low-level ambient air environments. Annual means were calculated on a station specific basis from the results from each monitoring report for that year. Distance was calculated from the centre of the nearest radon source (e.g., above-ground tailings management facility (AGTMF), rock piles, ventilation shafts) to the location of the track etch cup rounded to the nearest 0.5 km. Thus, for spatially large radon sources (e.g., above ground tailings management facilties) monitoring stations situated directly on source margins may be identified as being hundreds of meters from the point of release. Surface water: The mine/mill sites have extensive surface water monitoring programs. However, this database has been restricted to those watersheds directly receiving treated mine/mill effluent; the primary source of COPCs to the environment. Water was collected using surface water grab samplers. Sampling frequency ranges from weekly, monthly, quarterly, bi-annually to annually. Higher sampling frequency occurs at stations nearest to the point of release. Distance from point of release was measured to the specific sampling station. Fish: Fish were collected using a variety of sampling methods including nets, angling and boat electrofishing. The data presented here are flesh samples from large fish species most commonly eaten by local inhabitants; Whitefish (Coregonus clupeaformis), Longnose Sucker (Catostomus catostomus), Northern Pike (Esox lucius) and White Sucker (Catostomus commersonii). Results are presented for both nuclear and hazardous substances as fresh (wet) weight. Fish are collected on a cyclical basis, generally every three years though special investigations can result in an increased sampling frequency. Distance from point of release was measured to the approximate centre of the water body or bay within which the fish were collected. Sediment: Sediments were collected from depositional areas which can vary considerably among sites; lakes, rivers, and a few streams. Sediment samples consisted of the upper 2 cm collected using a Tech-Ops sediment corer. Sediments are collected on a cyclical basis, generally every three years though special investigations 15

17 can result in an increased sampling frequency. Distance from point of release was measured to the specific sampling station. The following statistics were generated for nuclear and hazardous substances for each of the exposure sampling stations. sample size arithmetic mean arithmetic standard deviation standard error number of samples below detection limit minimum / maximum 95 th percentile assuming a one-tailed normal distribution 95 th percentile assuming a one-tailed log-normal distribution Additional statistics were calculated for reference or background sites. Upper and lower levels based on two standard deviations of the arithmetic mean were calculated. These levels represent the 97.5 th percentile assuming a two-tailed normal distribution or a 95 th percentile assuming a one-tailed normal distribution Time Period for Statistical Analyses Air, Fish and Sediment: Statistics were calculated for the entire 13-year dataset (2000 for the air, fish and sediment environmental pathways. Surface Water: Statistics were calculated for the 13-year dataset for all of the COPCs. Where a COPC was greater than the Water Quality Guideline for the Protection of Aquatic Life (Canadian Council of Ministers of the Environment (CCME), 2014) at stations beyond 2 km of the treated effluent release point (i.e., generic off-site location), two additional time periods were assessed; a 10-year period ( ) and a 3-year period (2010. The year 2000 was selected as the start of all analysis as this was the year that the NSCA came into force. Under the NSCA, the regulatory oversight of the CNSC was broadened to encompass environmental protection, including the regulation of both nuclear and hazardous substances. As a result of increased oversight and the conduct of ERAs, additional risks with respect to surface water quality were identified by CNSC staff between 2000 and For example, CNSC staff identified additional risk for uranium as a chemical contaminant under the second Priority Substances List (Canadian Environmental Protection Act, 1999), as well as for the impacts of selenium and molybdenum through independent staff risk assessments under the NSCA. The period is indicative of effluent performance once treatment upgrades had been implemented. More details can be found in the companion report describing the CNSC environmental protection framework. The companion document also includes a short description of the mines and mills included in this assessment (CNSC, 2014a). 16

18 3 RESULTS Statistical summaries were prepared for the four exposure pathways for interpretation of spatial and temporal patterns relative to effluent release points. The results compare arithmetic means, where appropriate, to relevant federal or provincial standards, guidelines and criteria. Explanations and further details are provided when results are above these levels. Appendices at the end of the report provide sample calculations and additional graphs and tables which help further explain the results. 3.1 Ambient Air Quality Ambient Air Particulate Monitoring The concentrations of COPCs in the atmospheric environment were compiled for the13- year period (2000 as mentioned in the Methods section. The substances analyzed were: Hazardous substances: arsenic, cadmium, copper, lead, nickel, molybdenum, selenium, sulphur dioxide, uranium, zinc, and total suspended particulates. Nuclear substances: lead-210, polonium-210, radium-226, thorium-230, uranium (uranium-234 and uranium-238 calculated based on specific activity) Hazardous Substances All hazardous substances were below the relevant annual average ambient air quality criteria. Figure 2 provides examples of the 13-year annual arithmetic mean and corresponding standard error for selected contaminants (arsenic, cadmium, lead, nickel and uranium). The Ontario Ministry of the Environment s (MOE) Ambient Air Quality Criteria (OMOE, for metals and metalloids were used as there are no similar criteria from Saskatchewan or Environment Canada. Where necessary, the criteria were converted to an annual basis for comparison. Appendix A provides a sample calculation for this procedure. The criteria for sulphur dioxide and total suspended particulates were obtained from the Appendix of the Saskatchewan Clean Air Regulations. Table A.1 provides the summary statistics and table A.3 provides the relevant annual air quality reference levels used in this work. Table A4 provides the available Quebec air quality criteria, standards and converted annual levels for comparison purposes. All high volume air sampler stations are situated within the 0 to 2 km zone within which most particulate are expected to settle (based on site-specific dispersion modelling). Hence, as seen in figure 2, these results demonstrate that atmospheric emissions of particulate hazardous substances associated with uranium mining and milling do not pose a health risk to members of the public. 17

19 Figure 2: Average concentration of hazardous substances in particulates in air at uranium mines and mills ( Hazardous substances - 13 year period (2000- Ambient Air Quality Reference Levels 0.1 Concentration (µg/m 3 ) Arsenic Cadmium Lead Nickel Uranium Hazardous Substance Nuclear Substances Analysis was performed on the primary nuclear substances associated with the natural uranium decay chain; all were below reference levels. Figure 3 provides the 13-year annual arithmetic means and their corresponding standard errors. Nuclear substance reference levels were calculated based on the air concentration that would result in a dose a factor of ten less (i.e., 0.1 msv per year) than the 1 msv per year regulatory annual dose limit for members of the public in the CNSC Radiation Protection Regulations. This is a similar approach to that used by the World Health Organization and Health Canada for the calculation of drinking water guidelines for radionuclides. Appendix A provides sample calculations for these reference levels. Table A.5 of Appendix A summarizes the calculated values. The combined total dose for the air pathway from all the nuclear substances presented in Figure 3 is msv which is also well below the 1 msv per year dose limit for members of the public (see appendix A for calculation methods). It should be noted that these results over-predict the dose associated with uranium mining and milling as natural background levels are included in these calculations. The public dose limit is only applicable to incremental exposure in addition to natural background. 18

20 As stated in the previous sub-section, the high volume air sampler stations are situated in the 0 to 2 km zone within which most particulate materials are expected to settle (based on site-specific dispersion modelling). Hence, as seen in figure 3, these results demonstrate that atmospheric emissions of particulate nuclear substances associated with uranium mining/milling do not pose a health risk to members of the public. Figure 3: Average concentration of nuclear substances in particulates in air at uranium mines and mills (2000- Nuclear substance - 13-year period (2000- Reference level (0.1 msv per year exposure) Concentration (Bq/m 3 ) Pb-210 Po-210 Ra-226 Th-230 U-234 U-238 Nuclear substance Radon-222 Radon is an inert gas that cannot be measured using high volume air samplers. Radon monitoring at the uranium mines and mills is completed using passive track etch air samplers. The mine and mill was the only site with both pre-operational and operational radon monitoring at exposure sites. This allowed for the comparison of the pre-operational baseline range to the 13-year average for each of the stations during the operational phase (figure 4). Pre-operational data were collected between 1988 and 1990; operations began in The average of the pre-operational radon data was 24 Bq/m 3 with an upper bound (average + 2 standard deviations) of 58 Bq/m 3. Summer outdoor radon monitoring completed by Grasty (1994) in 1990 and 1991 reported southern Saskatchewan outdoor radon levels of 61 Bq/m 3 and 15 Bq/m 3, respectively, with the variations believed to be a result of seasonal variation in soil moisture. More recent work 19

21 by Grasty and LaMarre (2004) calculated a population-weighted annual concentration of 13.5 Bq/m 3 for outdoors based on outdoor concentrations measured for 17 Canadian cities. The Canadian population-weighted annual concentration is presented as the blue dashed line in Figure 4. This value is lower than the baseline average but within the baseline range. Figure 4: Radon monitoring data at the Mine and Mill (including pre-operational baseline data) Radon Concentration (Bq/m 3 ) Reference + 2 standard deviations Canadian average Distance (km) All radon activity levels from, except for one onsite station, were within the pre-operational baseline activity levels. The single elevated value (218 Bq/m 3 ) was observed at a distance less than 0.5 km from the emission source. Elevated levels are expected in close proximity to emission sources (e.g., exposed tailings facilities, ore piles, underground ventilation shafts where there would be no public access). Figure 4 demonstrates that radon levels from the mine and mill rapidly decrease with distance from source and that members of the public would not be exposed to levels greater than the site baseline. Radon levels greater 2 km away are similar to the Canadian background average. Figure 5 summarizes the combined radon data from all four sites for comparison to background radon levels derived from the reference or control monitoring stations from the radon monitoring programs (i.e., pre-operational baseline data not included). The background (control) radon levels averaged 27 Bq/m 3 with an upper 20

22 bound (average + 2 standard deviations) of 46 Bq/m 3. Thus the reported background range is similar to that for the pre-operational baseline, and as previously discussed encompasses radon levels reported in the literature for Saskatchewan and across Canada (Grasty 1994; Grasty and LaMarre 2004). To assist in the interpretation of the results, figure 5 has been subdivided into two panels, figure 5A, and 5B. In figure 5A the high radon stations associated with the historical Key above ground tailings management facility (AGTMF: not considered to represent modern mining practices) have been removed to facilitate (i.e., enlarge the visual scale) the interpretation of the off-site (> 2 km) radon levels 4. Figure 5: Operational Radon monitoring data at four Canadian uranium mines and mills with (B) and without (A) the above-ground tailings management facility 300 A B Radon Concentration (Bq/m 3 ) Radon Concentration (Bq/m 3 ) Reference + 2 standard deviations Distance (km) 50 Reference + 2 standard deviations Canadian average Distance (km) A: Not including stations associated with the AGTMF B: including stations associated the AGTMF 4 Note: AGTMF stations are identified as being. 0.5 Km from source. These stations are actually located directly on the AGTMF but are approximately 350 m (rounded to nearest 0.5 km) from the centre of the TMF. 21

23 Figure 5A demonstrates that radon levels rapidly decline with distance. Mean values for all stations greater than 2 km from the nearest emission source were within the regional background range levels, and at or near the Canadian average (Grasty and LaMarre 2004). The data support a conclusion that a modern uranium mine would not expose members of the public to radon levels measurably above background. 3.2 Aquatic Environment At a modern uranium mine/mill, contaminated waters are intercepted and re-routed from throughout the site to water treatment plant(s) for treatment prior to release to the receiving environment. The watersheds receiving treated effluent are the focus of comprehensive aquatic monitoring programs. To aid in the interpretation of the results from the aquatic program a brief summary is provided of the effluent treatment facilities and the watersheds they release to. The Rabbit and McArthur River operations have a single water treatment facility processing all collected contaminated waters at the site. At Rabbit these waters are released on a continuous flow basis to the headwaters of the Horseshoe Creek which flows to Hidden Bay of Wollaston (figure 6, insert). The McArthur River treatment plant releases to holding ponds where water is tested prior to being released in batches to the drainage system. The and operations have operated two water treatment facilities at various times over the assessment period. At (figure 8, insert) the release point for both treatment plants is Sink Reservoir which flows through a control structure to Vulture, with the ultimate final point of release being from Vulture via a diffuser to of the system. The Sink and Vulture control system is referred to as the S-V Treated Effluent Management system (S-V TEMS). It is designed to enhance near-field settling of COPCs and ensure adequate volume control to protect water quality and the natural flow regime and channel integrity of the system. The operation has two water treatment plants releasing to different watersheds. Water from dewatering wells associated with maintaining water levels within the Deilmann North tailings management facility is sent to the Reverse Osmosis (RO) Effluent Treatment Plant. Clean treated water from the RO plant is discharged into the McDonald Creek system. The concentrated waste stream from the RO plant is sent to the main effluent treatment plant which treats contaminated water using a chemical precipitation process. This plant also receives contaminated waters from throughout the site and the mill. Upon treatment these waters are stored in holding ponds and tested for quality prior to being released in batches to the system which flows to the Wheeler River (figure 9, insert). Releases from these effluent treatment plants must meet Environment Canada s MMER as well as additional requirements of the CNSC. As of 2013, the uranium mines and mills continue to be the top performing mining sector with respect to compliance with the MMERs; a performance they have achieved since the coming into force of this regulation in The most recent public summary of effluent quality for 2012 is provided below 5 Summary reports are available at 22

24 to place the performance of the uranium mining sub-sector into perspective relative to the other metal mining sub-sectors in Canada (table 3). Table 3: A sector comparison of average effluent parameter concentrations, 2012 (CNSC 2014b) Parameters MMER limit Uranium Base metals (e.g., nickel, copper) Precious metals (e.g., gold) Arsenic (mg/l) Copper (mg/l) Lead (mg/l) Nickel (mg/l) Zinc (mg/l) TSS (mg/l) Radium-226 Iron (Bq/L)* ph low ph high * Bq/L Becquerel per litre For a more detailed review of the performance of the Canadian uranium mining and milling sector with respect to all safety and control areas including environmental protection as required by the NSCA see the latest CNSC Staff Report on the Performance of Uranium Mine and Mill Facilities: 2013 (CNSC 2014b). This document was presented to the Commission during the October 1, 2014 public meeting Surface Water The currently operating uranium mines and mills are required to have comprehensive surface water quality monitoring programs. Monitoring within watersheds receiving treated effluents is extensive, with sampling stations located at multiple sites along a drainage. Sampling frequency ranges from weekly to monthly in the near-field, decreasing in frequency with increased distance from the point of effluent release. The CNSC requires reporting of an extensive list of water quality parameters. These far exceed those required within the MMER, including the associated requirements for Environmental Effects Monitoring. This report addresses the COPCs commonly monitored as per table 1. Tables B.1 B.23 in appendix B contain the surface water monitoring station names, distances downstream from the effluent release point, means and associated statistics for local background (reference) stations (table B1) and for each COPC (tables B.2 B.23). Figures B.1 to B.23 display the mean and standard error of concentrations with distance from the effluent release point, the local background concentration range (mean + 2 standard deviations for reference data) and applicable Drinking Water Quality Guidelines (Health Canada, and Canadian Water Quality Guidelines for the Protection of Aquatic Life (CCME, 2014). 23

25 Drinking Water Quality Drinking water quality guidelines are not regulatory limits and are generally only applicable to drinking water sources such as drinking water plants and/or wells. They are presented here to provide perspective on water quality. Should a uranium mine/mill be proposed on a watershed used as a source of drinking water, specific restrictions would be placed to ensure drinking water was protected. All nuclear and hazardous substances in surface water beyond 2 km from the effluent release points were below the applicable Maximum Allowable Concentration (MAC) or Aesthetic Objective in Health Canada s Guidelines for Canadian Drinking Water Quality (, with the exception of uranium and manganese. Of particular note, all radiological parameters (lead-210, polonium-210, radium-226 and thorium-230) were well-below the MAC, even within 2 km of the effluent release point, and all concentrations beyond 2 km were similar to local background (reference) values. Uranium: Figure B.1 indicates that mean uranium concentration were below the drinking water MAC for all stations with the exception of the first Horseshoe Creek monitoring stations receiving effluent from the Rabbit operation. Within the 13-year assessment period the CNSC identified uranium releases at Rabbit as being unacceptable and required upgrades to the treatment system to reduce releases (CNSC 2009). Figure 6 provides a comparison of uranium water quality prior to treatment upgrades ( ) and post-treatment upgrades (2009 -, clearly demonstrating a substantial improvement in water quality. Surface water uranium concentrations beyond the 2 km range 6 decreased to an average of mg/l, well below the MAC of 0.02 mg/l (table B.2) with the upgrades to the water treatment facility. Any future proposed uranium mine/mill will be required by the CNSC to meet or exceed the uranium in effluent quality presently being achieved by existing uranium mining and milling operations (CNSC 2009). Manganese: Figure B.12 displays manganese concentrations downstream relative to local background concentrations and the drinking water quality objective. As the natural background substantially exceeds the guideline and all the exposure stations are well within natural background variability it is clear that uranium mining and milling is not influencing manganese levels. These concentrations are the result of natural sources of manganese in the environment from weathering of soils, rocks and minerals. Note that this guideline is an aesthetic objective (based on taste and staining of laundry) and is not a health related guideline. The assessment results demonstrate that the release of treated mine and/or mill effluent is regulated by the CNSC to ensure that drinking water supplies are not placed at risk. 6 Note that distance from source in Figure 6 measured from the effluent release point down the drainage system (slightly increases distance due to variations in stream course) rather than being straight linear distance. 24

26 Protection of Aquatic Life Water Quality Guidelines for the Protection of Aquatic Life (WQGAL) (CCME, 2014) are developed on a Canada-wide basis to protect all forms of aquatic life and all aspects of the aquatic life cycles. These guidelines consider effects on the most sensitive life stage of the most sensitive species over the long term, based on published toxicological data. They are often substantially lower than human drinking water guidelines. The aquatic life guidelines are not regulatory limits. Due to their conservative nature (i.e., highly protective) they serve as screening criteria to indicate when there is a potential risk to aquatic life that may merit further risk assessment, monitoring or specialized investigations. It is not unusual for some effluent constituents to exceed these guidelines in the nearfield, particularly when releases are to low dilution (i.e., low flow) headwaters as is common in mining operations. This is addressed in site-specific risk assessments and monitoring programs with predicted exceedances carefully monitored (chemical and biological effects monitoring) and unpredicted exceedances triggering investigations to assess the potential ecological effects of the exceedance and whether mitigative action is required. Uranium, selenium, and molybdenum exceeded the WQGAL at one or more monitoring stations as a result of mining or milling activities. Additional exceedences (cadmium, copper, lead, TSS, and ph) were not due to effluent releases. These COPCs are discussed in further detail in the following sections, commencing with uranium, selenium and molybdenum as they have received enhanced CNSC regulatory oversight in recent years. CNSC Regulatory Action for U, Mo, Se Uranium, selenium and molybdenum are three effluent constituents that have received additional CNSC regulatory attention with the coming into force of the NSCA and the enhanced responsibilities associated with hazardous substances 7. Over recent years regulatory action by the Commission has required water treatment system upgrades for these substances. These upgrades were generally installed and commissioned by the end of To demonstrate the efficacy of these treatment upgrades the 13 year assessment period (2000 is supplemented by the presentation of two additional periods; pretreatments upgrades ( ) and post-treatment upgrade (2010- for these three effluent constituents. Uranium: The Rabbit operation is the only site where the WQGAL (0.015 mg/l) was exceeded beyond the 2 km zone (figure B.1). As discussed in the drinking water section, regulatory action required the implementation of upgrades to the water management and treatment systems to reduce uranium releases. These upgrades succeeded in substantially reducing effluent uranium concentrations which subsequently resulted in improvements in Horseshoe Creek surface water quality. This is clearly demonstrated in Figure 6, with 7 The NSCA, promulgated in 2000, added hazardous substances to the environmental protection mandate of the federal nuclear regulator. 25

27 Horseshoe Creek waters exhibiting considerably improved water quality such that uranium concentrations currently achieve the WQGAL prior to entering Hidden Bay. CNSC regulatory requirements to upgrade the Rabbit treatment system have resulted in substantial improvements in downstream water quality. Any future proposed mining operation would be required to have similar or better treated effluent quality for uranium. 26

28 Figure 6: Uranium surface water concentrations in the Horseshoe Creek system downstream of the Rabbit mill treated effluent release point 0.18 Rabbit Mine and Mill - Horseshoe Creek Uranium in Surface Water (mg/l) : Horeseshoe Pond - Downstream from Wier 3 (Effluent outlet) (2 km) 3.2: Horseshoe Creek (Effluent Stream Prior to Hidden Bay) (6.6 km) 3.2.2: Hidden Bay Near Horshoe Creek Outlet (7.4 km) 3.4: Hidden Bay (8.6 km) Distance from Source along the Watershed (km) Protection of Aquatic Life Guideline 27

29 Selenium: Mean selenium surface water concentrations are displayed in figure B.2 for About half of the surface water monitoring stations between 2 and 10 km had mean concentrations that were both above the local background range and above the current Canadian WQGAL of mg/l. These stations were located downstream of mill effluent release points at the Rabbit Mine and Mill, the Mill and the Mill. Selenium concentrations in surface water beyond 2 km downstream of the McArthur River Mine treated effluent release point and the Reverse Osmosis treatment facility at were below the WQGAL and within the range of local background. Concentrations at all monitoring stations beyond 10 km downstream of all uranium mines and mills were below local background and the WQGAL. In 2006, CNSC staff completed an independently peer-reviewed ecological risk assessment (EcoRA) of the operation. This was done to determine whether operations remained within the scope of effects anticipated (licensing basis), and/or whether additional regulatory controls were merited to minimize impacts. Based on seven lines of evidence, CNSC staff s conclusion was that releases of treated effluent from the mill over the 30 plus life-span of the operation had resulted (e.g., selenium) and could result (e.g., molybdenum) in unacceptable environmental effects. Additional details can be found in the companion document (CNSC, 2014). As a result of the EcoRA, the Commission required the operation to upgrade their treatment system to reduce selenium and molybdenum concentrations in the effluent. McArthur River Mine, Rabbit Mine and Mill and Mill also pro-actively undertook effluent treatment optimization projects to reduce releases of selenium and molybdenum to the surface water environment. These process improvements were largely operational by Figures 7 through 9 display selenium concentrations at distance along the watersheds from the effluent release points at the Rabbit Mill (Horseshoe Creek ), the Mill (Collin s Creek ) and the Mill ( ) for the periods of and At the Rabbit operation mean selenium surface water concentrations decreased between the two time periods at 3.1 (about 2 km from the point of releases), however, concentrations continued to be above the WQGAL (figure 7). Concentrations at 3.2, further down the drainage (approximately 6.6 km) have not yet demonstrated a decrease post-treatment and continued to be above the WQGAL. Beyond this station, selenium concentrations were below the WQGAL. Figure 8 provides mean selenium surface water concentrations for the two periods for stations downstream of the Mill. The two nearest downstream stations are situated within the Sink-Vulture Treated Effluent Management or SV-TEMS. The S-V TEMS is designed to hold water containing higher amounts of treated effluent to allow for the settling of contaminants to the sediments, and to protect stream channel integrity in. Mean concentrations in the immediate near-field (about 0.6 km) within Sink Reservoir decreased between the two sampling periods though the error bars indicate substantial fluctuations through time. Concentrations for both periods exceeded the WQGAL. Mean concentration at the adjacent Vulture station 28

30 (approximately 2.7 km from the point of release) fluctuated around the WQGAL being just below in and above in Mean selenium concentrations at all stations downstream of Vulture, from 5 to 25 km, were below the WQGAL for both time periods demonstrating that the SV TEMS is, as designed, protecting the downstream system. 29

31 Figure 7: Selenium surface water concentrations in the Horseshoe Creek system downstream of the Rabbit Mill treated effluent release point Rabbit Mine and Mill - Horseshoe Creek Selenium in Surface Water (mg/l) : Horeseshoe Pond - Downstream from Wier 3 (Effluent outlet) (2 km) 3.2: Horseshoe Creek (Effluent Stream Prior to Hidden Bay) (6.6 km) 3.2.2: Hidden Bay Near Horshoe Creek Outlet (7.4 km) 3.4: Hidden Bay (8.6 km) Distance from Source along the Watershed (km) Protection of Aquatic Life Guideline 30

32 Figure 8: Selenium surface water concentrations in the Collin's Creek system downstream of the Mill treated effluent release point Mill Selenium in Surface Water (mg/l) WQ09E: Sink Reservoir (0.6 km) WQ10E: Vulture (2.7 km) WQ11E: East Basin (4.9 km) WQ12E: Below (flow metering actually at SG8) (7.1 km) WQ13E: Below Highway 905 (14.8 km) WQ14E: Kewen (25.1 km) Distance from Source along the Watershed (km) Protection of Aquatic Life Guideline 31

33 Figure 9 displays mean selenium surface water concentrations in the, downstream of the Mill, for and Mean selenium concentration in surface water downstream of the Mill decreased significantly between and at all monitoring stations. Mean surface water concentrations at monitoring stations between 1.4 and 6.3 km downstream remained above the WQGAL of mg/l in ; however, the mean surface water concentration 12.3 km downstream at Delta ( 3.3) decreased to mg/l during Concentrations were below laboratory detection limits at s and 3.2, located 15.7 and 21.5 km respectively downstream at the Key Mill in An exceedance of the selenium WQGAL indicates the potential for effects on fish reproductive success, however, recent scientific advances have demonstrated that fish tissue levels are more reliable indicators than selenium water concentrations (Chapman et al, 2010). The CNSC required investigations of selenium in fish tissue at all of these sites. Scientific evidence of selenium related effects at the operation resulted in the Commission requiring the implementation of selenium treatment and the development and implementation of a specialized selenium recovery monitoring program by this licensee. The objective is to reduce releases of selenium and demonstrate a corresponding reduction of selenium in the abiotic and biotic media of the receiving watershed. Surface water quality is considered a short-term, rapid indicator and has already demonstrated substantial reduction in the receiving environment (figure 9). Concentrations in sediments and biological tissues (macrophytes and fish) are measured less frequently as they are predicted to respond more slowly to the improvements in effluent quality. To date selenium levels in these environmental compartments have remained relatively stable. At other sites, it is CNSC staff s assessment that the concentrations of selenium in the receiving environment are not at levels indicative of potential for fish reproductive effects. In addition to the upgrades in effluent treatment systems, continued monitoring of selenium in water, sediments and fish tissues (flesh with increasing attention being directed towards eggs) is required at all of these sites. These programs will provide early warning of any developing risks to fish health. Any proposed new operation would be required to include selenium within their sitespecific risk assessment and to produce selenium effluent quality similar to or better than that currently being achieved by the existing upgraded water treatment systems. CNSC specialist staff are also assisting Environment Canada in their current proposal to include selenium effluent limits in the MMERs as selenium releases are not unique to uranium mining (table 4). 32

34 Figure 9: Selenium surface water concentrations in the David s Creek system downstream of the Mill treated effluent release point Mill Selenium in Surface Water (mg/l) : Wolf Outflow (1.4 km) 3.9: Yak Creek (1.9 km) 3.8: David Creek (2.3 km) 3.9.1: Pyrite Creek (6.3 km) 3.3: Delta (12.3 km) Distance from Source along the Watershed (km) Protection of Aquatic Life Guideline 3.9.2: Delta Outflow (15.7 km) 3.2: Wheeler River (Downstream of ) (21.5 km) 33

35 Table 4: Selenium concentration (mg/l) in treated effluent by metal mining sector in * Metal mining sector Selenium concentration (mg/l) Uranium Base metals Precious metals Iron * CNSC 2014b: Summary period based on effluent concentrations submitted to Environment Canada as part of the MMERs Molybdenum: Mean molybdenum surface water concentrations downstream of treated effluent release points are showed in figure B.3 for Nine surface water quality monitoring stations beyond 2 km had concentrations above the range of local background, with four stations exceeding the WQGAL (0.073 mg/l). These exceedances were for the first station beyond the 2 km zone for each of Rabbit,,. Molybdenum is another substance identified by the CNSC staff EcoRAs as meriting additional regulatory action. Unlike selenium, molybdenum posed a theoretical risk (i.e., no field evidence of biological effects), however, as demonstrated treatment technology was available, the Commission required system upgrades based on the principle of pollution prevention and the precautionary principle. These process improvements were largely operational by Figures 10 through 12 compare molybdenum concentrations at distances along each of the relevant watersheds for the assessment periods of and At the Rabbit operation, mean concentrations in the Horseshoe Creek system decreased significantly between these time periods at s 3.1 in Horseshoe Pond and 3.2 in Horseshoe Creek (figure10). This was a result of the effluent treatment improvements at the Rabbit Mill. Concentrations at all monitoring stations downstream of the Rabbit Mill were below WQGAL in Figure 11 provides mean molybdenum surface water concentrations for the Mill. Molybdenum releases at this, the most modern of the uranium milling operations, were addressed early in operations and releases have always been significantly lower relative to the other facilities. Mean molybdenum concentrations were above the WQGAL within both water bodies of the SV TEMS. In Sink reservoir molybdenum increased in compared with , though concentrations at the Vulture station decreased significantly in compared with Concentrations beyond Vulture, in the east basin and further downstream in the Collin s Creek were below the WQGAL during both periods. 34

36 Figure 12 displays mean molybdenum surface water concentrations in the, downstream of the mill, for and Concentrations in surface water downstream of the mill decreased significantly between and at all stations. Concentrations between 1.4 and 6.3 km downstream remained above the WQGAL in ; however, the concentrations 12.3 km downstream at Delta ( 3.3) decreased to mg/l during , compared with mg/l in Concentrations were below laboratory detection limits at s and 3.2, located 15.7 and 21.5 km respectively, downstream of the mill during As a result of CNSC regulatory action, the uranium mining sub-sector has seen a significant reduction in molybdenum releases in recent years. This is clearly demonstrated in Figure 13 showing average molybdenum effluent concentrations for the various metal mining sub-sectors in Canada. Molybdenum releases in the uranium subsector have dramatically declined from the highs of the early 2000s, such that they are presently equal to those of the precious metal and iron ore sub-sectors, and well below those of the base metal subsector. 35

37 Figure 10: Molybdenum surface water concentrations in the Horseshoe Creek system downstream of the Rabbit Mill treated effluent release point 3.5 Rabbit Mine and Mill - Horseshoe Creek Molybdenum in Surface Water (mg/l) : Horeseshoe Pond - Downstream from Wier 3 (Effluent outlet) (2 km) 3.2: Horseshoe Creek (Effluent Stream Prior to Hidden Bay) (6.6 km) 3.2.2: Hidden Bay Near Horshoe Creek Outlet (7.4 km) 3.4: Hidden Bay (8.6 km) Distance from Source Along the Watershed (km) Protection of Aquatic Life Guideline 36

38 Figure 11: Molybdenum surface water concentrations in the Collin's Creek system downstream of the Mill treated effluent release point 0.4 Mill Molybdenum in Surface Water (mg/l) WQ09E: Sink Reservoir (0.6 km) WQ10E: Vulture (2.7 km) WQ11E: East Basin (4.9 km) WQ12E: Below (flow metering actually at SG8) (7.1 km) Distance from Source along the Watershed (km) WQ13E: Below Highway 905 (14.8 km) WQ14E: Kewen (25.1 km) Protection of Aquatic Life Guidelines 37

39 Figure 12: Molybdenum surface water concentrations in the system downstream of the Mill treated effluent release point 0.6 Mill Molybdenum in Surface Water (mg/l) : Wolf Outflow (1.4 km) 3.9: Yak Creek (1.9 km) 3.8: David Creek (2.3 km) 3.9.1: Pyrite Creek (6.3 km) 3.3: Delta (12.3 km) Distance from Source along the Watershed (km) 3.9.2: Delta Outflow (15.7 km) 3.2: Wheeler River (Downstream of ) (21.5 km) Protection of Aquatic Life Guideline 38

40 Figure 13: Average treated effluent concentration of molybdenum by metal mining sector (CNSC 2014b) This improved effluent quality is expected to continue to lead to rapid reductions in the receiving environment as molybdenum, unlike selenium is not strongly cycled within biological systems. Any future proposed uranium mine would be required to meet or exceed existing effluent performance with respect to molybdenum, hence, molybdenum is not expected to pose a risk to the environment in a new uranium mine or mill. Additional COPCs in Surface Water Results for the remaining contaminants with one or more stations having concentrations above the WQGAL are discussed below. For each contaminant, a figure is provided in Appendix B with mean concentrations in surface water downstream of uranium mine and mill treated effluent discharge points for Tables are also provided with mean concentrations and associated statistics at local background stations (reference: table B.1) and monitoring stations downstream of effluent release points (exposure: other tables in Appendix B). Cadmium (figure B.9, tables B.1, B.10): The mean range of concentrations for cadmium was within the range of local background concentrations and well below the drinking water guideline with the exception of the furthest station. This station mean represents only two samples both obtained using analytical methods with very different method detection limits. Due to the extremely low cadmium WQGAL for aquatic life and the difficulty in obtaining such low laboratory method detection limits, it can only be stated that cadmium concentrations were below analytical detection limits for most of this monitoring period. Improved laboratory detection limits for analyses completed in the last few years ( : Appendix B) have allowed a better assessment of cadmium in the receiving environment. When the analysis is limited to the last three years (table 5), cadmium concentrations have not only been within background ranges but also below the 39

41 WQGAL (table 5). Hence effluents from uranium mines/mills have not adversely affected water quality with respect to cadmium. Table 5: Average cadmium concentration for the period compared to the WQGAL corrected for station specific hardness Distance from point of effluent release (km) Average concentration (mg/l) Hardness corrected guideline* (mg/l) Below guideline? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 9 n/a n/a n/a Yes Yes 15.0 n/a n/a n/a n/a = not analyzed at this location from * The WQGAL was calculated using the hardness formula associated with the guideline. Copper (figure B.10, tables B.1, B.11): Mean copper concentrations at all stations beyond 2 km were within the background range indicating no measurable uranium mining/milling influence beyond the site boundary. Two stations report values above the WQGAL (0.002 mg/l). However, all samples from these stations were below the method detection limit that was used. As copper concentrations at stations upstream of these sites, analyzed more frequently using better (lower) detection limits, are below the WQGAL, there is no reason to believe waters at these two stations would be exhibiting elevated 40

42 copper levels. Hence, effluents from uranium mining/milling are not adversely affecting water quality with respect to copper. Lead (figure B.11, tables B.1, B.12): Two surface water sampling stations report mean values greater than both the background and the WQGAL, though this is a result of high method detection limits rather than a reflection of water quality. Both these Watershed sampling stations downstream of the mill reported values at the analytical method detection limit, which was in itself greater than the WQGAL and the range of local background. Since stations located closer to the point of release in this watershed have lower lead values this result is considered an artifact of the high method detection limit and not evidence of a mining related effect. Hardness (figure B.20, tables B.1, B.21): Hardness is the concentration of calcium and magnesium ions expressed as equivalent of calcium carbonate (CaCO 3 ). There are no water quality guidelines for the protection of aquatic life for hardness. Figure B.20 shows that calcium carbonate concentration is above the range of local background in nine out of 14 monitoring stations beyond 2 km. Increased hardness can have a nutrient effect on biota living in surface water with hardness higher than local background. Low hardness is typical of natural surface water in the Athabasca Basin. Hardness can change the way metals behave in these environments, in particular it can reduce uptake and hence their toxicity to biota. ph (figure B.21, tables B.1, B.22): ph is a measure of the acidity or alkalinity of a solution. Solutions with a ph less than seven are acidic, while those with a ph greater than seven are basic or alkaline. A ph level of 7.0 is 'neutral'. All mean ph surface water values beyond 2 km were within the WQGAL and local background, with the exception of a monitoring station 4.2 km downstream of the effluent release point ( 3.9.1, Pyrite Creek at ph 5.04, table B.23). Depressed ph in this area has been attributed to natural acid generating conditions that are not attributable to the treated effluent. s both upstream and downstream of this station have ph values within the WQGAL and local background conditions. Furthermore treated effluent quality has always complied with the MMER limit for ph (6.0 to 9.5). Total Suspended Solids (TSS) - (figure B.22, tables B.1, B.23): The WQGAL for TSS is 5 mg/l above local background. The TSS concentrations in surface water at all monitoring stations were within the range of local background and below the WQGAL. However, the mean and range in TSS concentrations at 3.2, located 15 km downstream of the Mill treated effluent release point was high. TSS was measured at 3.2 four times between 2000 and The values were 4.6 and 5.0 mg/l for two samples from 2000, 3.2 mg/l for a sample from 2002, and 24.7 mg/l for a sample from The 2007 value is clearly anomalous. Regardless, TSS values in uranium mine and mill effluents have always been below the 15 mg/l MMER Limit. Therefore this anomalous result is not attributable to effluent Monitoring of COPCs in Fish Flesh This section presents the results of the fish flesh chemistry monitoring programs completed within the effluent receiving watersheds. 41

43 Figures C.1 to C.14 display the mean and standard error of hazardous and nuclear substances concentrations at different distances from the effluent release point and the local background concentrations (mean ± 2 standard deviations for reference data) for For the purpose of assessing the significance of human exposures to hazardous substances, toxicity reference concentrations in fish flesh for an intake or consumption rate of g of fish per day were calculated and are indicated by a red line on the hazardous contaminant figures (figures C.1 to C.10). The source of this fish consumption rate is the Hatchet dietary survey (CanNorth 2000), which was completed to provide regional dietary information for human health risk assessments associated with uranium mining activities in northern Saskatchewan. This represents a diet extremely high in fish to allow for a very conservative assessment. For example, the average consumption rate for an adult male in the Hatchet survey was 208 g/day, a value very similar to Health Canada s (2004) recommended value of 220 g per day (Richardson 1997) to represent native Canadian diets high in fish. Hence, the derived reference levels used here are very conservative and will over-predict risk. The calculation method, assumptions and rationale for the toxicity reference values for hazardous substances are described in Appendix C. To assess the significance of human exposures to nuclear substances, an approach similar to that used for the derivation of the ambient air reference value was selected. Fish flesh concentrations equivalent to an effective radiation dose of 0.1 msv per year (one-tenth of the public dose limit) for a daily fish consumption rate of g of fish were calculated. The calculation method, assumptions and rationale for the reference concentrations are provided in Appendix C. These reference concentrations are indicated by a red line on figures C.11 to C.14. Note that the regulatory limit is based on incremental dose above background, hence, only applies when radionuclides levels exceed natural background as a result of the licensed activity. Beyond the theoretical site boundary (i.e., > 2 km), the hazardous substance COPCs cadmium, copper, manganese, and zinc as well as all the nuclear substances were within the range of background conditions. This indicates that these substances are not accumulating in fish flesh beyond natural levels and are not discussed any further. Six COPCs; (arsenic, N=4 stations; lead, N=6 stations, molybdenum, N=7 stations, nickel, N=1 station; selenium, N=2 stations and uranium, N=1 station) were identified as being above regional background in one or more stations beyond 2 km. All of these COPCs, with the exception of selenium, were well below their respective reference criteria and do not pose a health concern. Beyond the 2 km zone only one COPC, selenium, was found to be exceeding both background and the reference criterion indicating a possible mining influence, meriting more follow up related to human health. Selenium (figure C.8): Selenium fish flesh concentrations exhibit substantial elevation above both background and the consumption toxicity reference concentration at two stations beyond the 2 km zone. The two stations where the highest values were found are associated with releases from the effluent treatment plant. These results played a role in the weight of evidence assessment used as the basis for CNSC regulatory action requiring upgrades to the water treatment system at this facility. The operation is required to perform an enhanced biological monitoring program in the 42

44 . The CNSC continues to carefully review these results to be able to detect any reduction in selenium fish concentrations in response to improvements in effluent quality. Arsenic (figure C.1): Although the mean concentrations of arsenic were above the local background concentrations, they were below the toxicity reference concentration and therefore do not represent a concern for human health. Lead (figure C.4): Concentrations of lead in fish flesh were at or just above local background concentrations at six of the seven monitoring stations located beyond 2 km of effluent release points. All fish flesh concentrations were below the toxicity reference concentration for lead. Molybdenum (figure C.6): Fish caught in areas not exposed to uranium mine and mill effluents have no detectable concentrations of molybdenum in their flesh (all below the method detection limit). Most fish flesh measured downstream of effluent release points had very low, but detectable concentrations of molybdenum, indicating slight accumulation. The measured levels (~ 10-2 µg/g range) were well below the toxicity reference concentration of 3.2 µg/g. Nickel (figure C.6): All exposure stations downstream of the water treatment plants were within background with the exception of McDonald, which has historically received dewatering water elevated in nickel. The measured levels in McDonald (~ 10-2 µg/g range) have been well below the toxicity reference concentration of 1.04 µg/g. A reverse osmosis (RO) treatment plant was installed in 1996/97 and was further expanded post Water quality released to the McDonald drainage has significantly improved with the fish flesh nickel levels decreasing in recent years. Uranium (figure C.9): Uranium fish flesh concentrations at all monitoring stations downstream of uranium mines and mills were within the range of local background values with the exception of one station at McDonald, downstream of the reverseosmosis groundwater treatment plant. This elevated mean value (0.044 µg/g) is strongly influenced, as demonstrated by the large error bars, by the results from the 2001 sampling program which reported a mean of µg/g. Three additional sampling events have occurred since 2001 with average fish flesh uranium concentrations steadily decreasing with each sampling event (2004: µg/g; 2007: µg/g: 2010 ( µg/g). Thus all samples collected after 2001 have been within the range of natural background and below the toxicity reference concentration. As mentioned, regulatory action required the construction of the reverse osmosis plant in the 1990s (initially in response to Ni concerns) with further expansion post This has resulted in a significant reduction in uranium concentration in both treated waters and the downstream receiving environment (CNSC, 2009 for detailed assessment). This has in turn been reflected in a decrease in U concentrations in fish flesh. Nuclear Substances (figures C.11 to C.14): Nuclear substance COPCs in fish collected beyond the 2 km theoretical site boundary exhibited flesh activity levels within the range of local background. Radium-226 (figure C.12) and thorium-230 (figure C.14) activity in fish flesh downstream of effluent release points was within the range of local background activities and well below levels that would result in a dose of 0.1 msv per year to a very high fish 43

45 consumer (600.8g per day). Lead-210 (figure C.11) and polonium-210 (figure C.13) are two of the most important contributors to natural background dose arising from fish consumption. These nuclear substances do not appear to be accumulating in fish flesh downstream of uranium mines and mills above natural background ranges. Altogether, the fish monitoring program indicates that of the COPCs measurable in fish flesh, selenium is the one demonstrated to increase in flesh as a result of effluent releases, to levels of potential risk to humans. Hence, any new proposed uranium mine or mill would be required to strictly limit the release of selenium to the environment Sediment Quality Sediment chemical analysis is required by the CNSC for all uranium mines and mills. Sediment monitoring is used to test facility predictions related to contaminant transport, support theoretical risk assessments (using sediment quality criteria or more complex modelling) and to interpret the results of biological monitoring programs for benthic macroinvertebrate communities and fish. Releases of treated effluent are expected to result in the accumulation of COPCs in the sediments of downstream water bodies, especially for those sites in operation for multiple years to decades. Thus, downstream sediments at uranium mines and mills such as Rabbit and will exhibit higher levels of COPCs as a result of their long operating histories (Rabbit 42 years; 32 years) than those of the more recent operations at and McArthur River (~ 15 years and 14 years, respectively). The sediments for the longer operating sites will also reflect poorer effluent quality during early years of operation. Figures D.1 to D.14 present the mean and standard error of hazardous and nuclear substances COPCs in sediments with distance from the effluent release point and the local background range (mean ± 2 standard deviations for reference data) for All reference (control) sediment monitoring stations were included in the background calculations with the exception of one water body. The water body removed from the database (Zimmer ) has highly unusual (naturally elevated) sediment concentrations for many of the COPCs. It was decided to err on the side of caution (inclusion of Zimmer sediment substantially increased upper background levels for comparison) and remove this lake from background statistical summaries. The applicable Interim Sediment Quality Guidelines for the Protection of Aquatic Life (ISQG) (CCME, 2014) and/or a Lowest Effect Level (LEL) from Thompson et al. (2005) are displayed using red lines on the figures. The ISQGs are derived from scientific data to protect the most sensitive aquatic receptor. The LELs (weighted method) were derived from statistical analysis of the presence / absence of benthic species downstream of uranium mines / mills in Saskatchewan and Ontario between 1985 and LELs represent concentrations below which adverse effects on benthic invertebrate communities are not expected. Exceedance of an LEL indicates the potential for biological effects that merit additional monitoring or investigation such as that provided by benthic macroinvertebrate monitoring programs. Beyond the theoretical 2 km lease boundary, three hazardous substance COPCs: copper (N=1), lead (N=1) and manganese (N=1), exceeded background levels but not sediment 44

46 quality criteria indicating that they do not pose a risk to aquatic life. Seven COPCs: arsenic (N=2), cadmium (N=2), molybdenum (N=6), nickel (N=3), selenium (N=2), uranium (N=2), and zinc (N=1), exceeded both background levels and sediment quality criteria at one or more stations, indicating the potential for effects on the benthic invertebrate community. As accumulation of COPCs in sediments is expected depending on the duration of operation of a facility, only those situations where both background and the relevant LELs are exceeded are discussed in the following sections. Molybdenum (figure D.6) Historical releases, especially those at the Rabbit and operations, have resulted in elevated levels of this COPC in the sediments. Most stations show significantly elevated concentrations of molybdenum, roughly 10 to 100 times the upper range of local background concentrations. The only stations not showing elevated molybdenum is the McDonald Creek watershed which has not received any effluents associated with the grinding or milling of ore. Selenium (figure D.8) Selenium is elevated in downstream sediments at levels that the CNSC considers to pose risk to biota. Two of eight stations located greater than 2 km downstream of effluent release points had sediment selenium concentrations above the local background concentrations. These water bodies are associated with the McArthur River and the operations, with selenium sediment concentrations in the latter being substantially elevated. As discussed in the previous sections, both of these sites have implement selenium risk management activities to address this contaminant. Uranium (figure D.9): Uranium sediment concentrations at two monitoring stations were greater than both the local background levels and the LEL; one station associated with the dewatering releases at the Key lake operation and the other with the McArthur River operation. Releases of metals, including uranium, have been addressed at the site with the addition (1990s) and further expansion (post 2002) of the reverse osmosis treatment plant. CNSC (2009) provides an extensive review of the performance of this treatment plant in reducing uranium levels released to this watershed. The McArthur River operation has also been successfully reducing uranium releases to surface waters. Nickel (figure D.7): The upper range of local background sediment nickel concentrations was almost equal to the ISQG. Nickel concentrations at three of eight stations located more than 2 km downstream were greater than the ISQG and the local background. Of these stations, two are situated in water bodies just beyond 2 km (both ~ 2.7 km), one is located in the Vulture part of the operation SV-TEMS (~ 2.7 km), one in the near-field of the McDonald Creek watershed (~ 2.7 km), and another at a midfar-field station (Delta ) in the watershed. The latter two are associated with the operation. Arsenic (figure D.1): The range in local background arsenic sediment concentrations was greater than both the ISQG and the LEL, reflecting natural high concentrations of arsenic in sediment in the region. Arsenic concentrations at two of eight sediment monitoring stations beyond the 2m km theoretical lease boundary were greater than local background concentrations. These stations were Vulture in the near-field (~ 2.7 km) ( operation) and Delta downstream of the operation. 45

47 Cadmium (figure D.2): Cadmium concentrations in sediments were above the ISQG and above local background concentrations at two of eight monitoring stations beyond 2 km of the effluent release points. Sediment cadmium concentrations measured in Hidden Bay Deep (4.8 km) at the Rabbit Mill, and at the Delta monitoring station (7.5 km) at the Mill, were greater than the ISQG and local background concentrations. Zinc (figure D.10): All concentrations of zinc in sediments beyond 2 km of the effluent release points were within the range of local background values except those at the McDonald monitoring station, 2.7 km downstream of the Reverse Osmosis Effluent Treatment Plant. Mean zinc sediment concentration at this station was 133 µg/g, greater than the ISQG of 123 µg/g. As stated previously, improved sediment quality downstream of the reverse osmosis plant may be achieved over time due to the improved effluent quality entering the McDonald Creek drainage system. Nuclear Substances (figures D.11 to D.14): There are no ISQG s for nuclear substances, though LELs were calculated by Thompson et al. (2005). The LELs for lead-210 (figure D.11) and polonium-210 (figure D.12) are lower than the range of local background values, these levels may be over-protective. Beyond the 2 km zone, no sediment radionuclide levels exceeded both background and the applicable LEL (figures D.11 D.14), with the exception of one station for lead-210 (figure D.11). Implications of Sediment Contaminant Accumulation The accumulation of COPCs in sediments is to be expected as it was predicted within the site-specific ERAs. ERAs also predicted effects on the benthic macroinvertebrate community within near-field water bodies. As a result, extensive benthic macroinvertebrate monitoring programs have been in place at the uranium mines and mills since the mid-1990s, pre-dating the environmental effects monitoring programs now required under the MMER. These programs have confirmed alteration of the benthic macroinvertebrate community, with impacts primarily restricted to near-field water bodies. The most consistent effect has been a reduction in the number of taxa, a response common to mining activities in general (Kilgour and CanNorth 2010; EC. Changes in benthic invertebrate density (number of individual organisms) have also been evident with exposure to mining effluents, though the direction of this change has varied depending on the mining sub-sector. Benthic communities exposed to iron ore effluents have tended to exhibit decreases in total density whereas those exposed to other mining effluents (precious metals, base metals and uranium mines) have tended to exhibit increases in total density (EC. 4 CONCLUSION The objective of this report was to use measured environmental quality data from currently operating uranium mining and/or milling facilities to present a realistic assessment of the potential exposures that one could expect for members of the public and environmental receptors from a modern high grade uranium mine/mill operating in a boreal environment and regulated under the NSCA. The compilation of air monitoring results demonstrates that such an operation would meet ambient air quality criteria for hazardous substances and therefore would not pose a risk to onsite workers or the public. The onsite air sampling results also demonstrate that 46

48 particulate nuclear substances in air would not pose a risk to public health, as individual nuclear substances can be expected to be below their respective reference levels (0.1 msv per year). Radon monitoring programs also demonstrate that levels in air rapidly decrease with distance from the source such that at a generic mine site boundary ( 2 km from a source), the public would only be exposed to levels of radon similar to natural background. Liquid effluent releases are the most significant source of contaminant release to the environment for a uranium mine and/or mill operating in a boreal environment. This assessment shows that with existing effluent treatment systems, radionuclide specific drinking water guidelines are achieved within the immediate receiving surface waters bodies with all other analytes meeting their respecting drinking water guidelines at all stations beyond an assumed 2 km surface lease boundary. Releases of treated mine and/or mill effluent are regulated such that drinking water supplies would not be placed at risk by a uranium mining and/or milling operation. The consumption of fish from water bodies receiving effluents can also be an important potential human exposure pathway. Five COPCs (As, Pb, Mo, Ni, U) demonstrated the potential for accumulation in fish flesh above background, though none of these approached the human health guidelines, even for an exceedingly high daily fish consumption rate. The data demonstrate that human consumption health guidelines could be exceeded for an individual with a diet high in fish obtaining all their fish from a selenium enriched ecosystem 8. The CNSC has required treatment of selenium in effluent of existing operations, in part, to ensure such a scenario does not develop. Any new proposed uranium mine or mill would be required to assess the site-specific selenium risks. Releases would be required to be at levels at or lower than those currently achieved by operating uranium mines/mills as well as being site-specifically protective of fish consumption practices. Due to the greater sensitivity (compared to humans) of some aquatic organisms to waterborne contaminants, effluent releases, if not properly managed, may pose a risk to aquatic life. The extensive water quality data collected downstream of uranium mines and mills indicate that uranium, molybdenum and selenium posed the greatest potential for impacting water quality beyond an assumed mine or mill site boundary (i.e., > 2 km from source). Uranium, selenium and molybdenum are also present in aquatic sediment above both background and their respective sediment quality guidelines in some near-field water bodies. This is also the case for a few other COPCs such as arsenic and nickel. Accumulation of COPCs in sediments is believed to be, at least partly, responsible for the changes in the sediment dwelling benthic invertebrate communities observed in some near-field effluent receiving water bodies. In addition, the characteristics of selenium in sediment are now known to be extremely important for the biological cycling of selenium and the effects on fish health identified at one operating uranium milling site. These results indicate that the COPCs of most concern at operating uranium mines/mills between 2000 and 2012 have clearly been uranium, molybdenum and selenium. Concerns related to these contaminants were identified by the CNSC in the late 1990s to early 8 No such scenario currently exists at the operating uranium mine or mill sites. 47

49 2000s. Subsequently, licensees were required to implement treatment system upgrades. Assessment of water quality since the installation of treatment system upgrades has demonstrated that uranium and molybdenum releases have been adequately addressed. These contaminants should not pose an environmental risk at any future facility designed to meet current CNSC requirements. Selenium releases from operating uranium mines and/or mills continue to require careful management. Any future uranium mine or mill would need to incorporate effluent treatment systems that adequately address selenium risk to sensitive receiving environments if they are to receive CNSC regulatory approval. The two most recent proposals for new mines in Saskatchewan have both included reverse osmosis within their proposed effluent treatment systems. This will provide additional benefits for control of all COPCs (nuclear and hazardous substances) associated with uranium mining, not only uranium, molybdenum and selenium. Other federal and provincial regulatory agencies are now also focusing their attention on selenium. Selenium is presently being assessed by Environment Canada under Canadian Environmental Protection Act, 1999 (CEPA) as a potentially toxic substance. It is also being proposed for inclusion in Environment Canada s MMER applicable to all mining operations in Canada. CNSC staff have been assisting both actions by providing scientific expertise, regulatory experience, effluent and receiving environment data and support. The focus of this assessment has been on the local environment associated with each of the presently operating uranium mines and mills. Complementary information is also available in recent publications of the Saskatchewan Government s Eastern Athabasca Regional Monitoring Program (EARMP). This program focus on the environment further away from operating uranium mines and mills at the communities of the Athabasca Basin most closely associated with uranium mining and milling sites. This EARMP community based program monitors the safety of traditionally harvested country foods through the testing of water, fish, berry and mammal (moose/caribou) chemistry for COPCs associated with uranium mining. The objectives of the program are to: Determine the safety of traditionally harvested food for local consumption. Establish long-term monitoring at community sampling areas to assess variability and potential changes over time. Build mutually beneficial relationships a well as engage and involve community members in the gathering of information for the program. Communicate monitoring results to community members and other stakeholders through reporting, public media and meetings. The 2014 EARMP report (CanNorth 2014) states: The evaluation of country foods data shows that most chemical concentrations are below available guidelines and similar to concentrations expected for the regions Furthermore, the associated human health risk assessment indicated that: 48

50 the non-radiological exposures to residents as a result of country food consumption are similar to those to members of the general Canadian population and are below values that are considered to be protective of health effects and therefore do not represent a cause for concern. Similarly, the radiological doses are below the public dose limit and as such are not a concern from a human health perspective. Overall, the results indicate that traditional harvesting of country foods does not present health risks to Athabasca basin residents. The reports and additional information on the EARMP program can be found at the following web site This compilation of the results of receiving environment monitoring programs associated with operating uranium mines and mills in Canada demonstrates that a uranium mine or mill regulated under the NSCA can be expected to operate in manner that protects human health and the environment. 49

51 REFERENCES Canadian Nuclear Safety Commission (CNSC), Environmental Protection Framework for Operating Uranium Mines and Mills under the Nuclear Safety and Control Act, Presentation to BAPE September a Canadian Nuclear Safety Commission (CNSC) CNSC Staff Report on the Performance of Uranium Mine and Mill Facilities: b. Canadian Nuclear Safety Commission (CNSC), Risk Management of Uranium Releases from Uranium Mines and Mills 2007 Annual Report. A joint report of the Canadian Nuclear Safety Commission and Environment Canada, 2009, Canada North Environmental Services Limited Partnership (CanNorth), Hatchet Dietary Survey Final Report. Prepared for the Atomic Energy Control Board. Project S. 274, Canada North Environmental Services Limited Partnership (CanNorth), Eastern Athabasca Regional Monitoring Program 2012 Technical Report, Prepared for the Government of Saskatchewan, 2014a, Canada North Environmental Services Limited Partnership (CanNorth), Eastern Athabasca Regional Monitoring Program 2012 Community Report. Prepared for the Government of Saskatchewan, 2014b, Canadian Council of Ministers of the Environment (CCME), Canada Environmental Quality Guidelines, 2014, Chapman, P. M., Adams, W. J.,Brooks, M.,Delos, C. G.,Luoma, S. N.,Maher, W. A.,Ohlendorf, H. M.,Presser, T. S.,Shaw, P Ecological Assessment of Selenium in the Aquatic Environment. CRC Press. Chen, J., Whyte, J, and K. Ford, An overview of radon research in Canada, Radiation Protection Dosimetry, (submitted). Environment Canada, Second National Assessment of Environmental Effects Monitoring Data from Metal Mines Subjected to the Metal Mining Effluent Regulations. National Environmental Effects Monitoring Office, Forestry, Agriculture and Aquaculture Division, Environment Canada, 2012, Grasty, R.L, Summer outdoor radon variations in Canada and their relation to soil moisture, Health Physics, Vol. 66: No. 2, pp , Grasty, R.L. and J.R. LaMarre, The annual effective dose from natural sources of ionising radiaton in Canada, Radiation Protection Dosimetry Vol. 108, No. 3, pp , Health Canada, Federal Contaminated Site Risk Assessment in Canada, Part 1: Guidance on Human Health, Preliminary Quantitative Risk Assessment (PQRA),

52 Health Canada, Guidelines for Canadian Drinking Water Quality Summary Table, 2012, Kilgour (Kilgour and Associates Ltd) and CanNorth (Canada North Environmental Services Limited Partnership), Feasibility of the Reference-Condition Approach for Uranium Mines, CNSC Research Contract R416.1, Justice Canada, Metal Mining Effluent Regulations, Justice Canada, Nuclear Safety and Control Act, pdf Ontario Ministry of the Environment, Ontario s Ambient Air Quality Criteria, 2012, Ontario Ministry of the Environment, Air Dispersion Modelling Guideline for Ontario (Version 2.0), Province of Saskatchewan, The Clean Air Regulations Appendix, Richardson, G.M. Compendium of Canadian Human Exposure Factors for Risk Assessment. Ottawa: O'Connor Associates Environmental Inc Thompson, P.A., Kurias, J. and S. Mihok, Derivation and Use of Sediment Quality Guidelines For Ecological Risk Assessment of Metals and Radionuclides Released to the Environment From Uranium Mining and Milling Activities in Canada, Environmental Monitoring and Assessment, Vol. 110, pp , US ATSDR Toxicological Profile for Uranium. United States Department of Health and Human Services, Agency for Toxic Substances and Disease Registry. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), Effects of Ionizing Radiation Volume II: Scientific Annexes C, D and E, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), Sources and Effects of Ionizing Radiation Volume I, Report to General Assembly, Scientific Annexes A and B,

53 ACRONYMS AGTMF Bq CCME CEAA Above-Ground Tailings Management Facility Becquerel Canadian Council of Ministers of the Environment Canadian Environmental Assessment Act CEPA Canadian Environmental Protection Act, 1999 COPC EEM ERA EcoRA ISQG LEL MAC MMER msv nbdl OMOE QA/QC RO S-V TEMS TSS WQGAL Contaminants of Potential Concern Environmental Effects Monitoring Environmental Risk Assessment (Human and Ecological) Ecological Risk Assessment Interim Sediment Quality Guidelines for the Protection of Aquatic Life Lowest Effect Level Maximum Allowable Concentration Metal Mining Effluent Regulations MilliSievert Number below analytical detection limit Ontario Ministry of the Environment Quality Assurance / Quality Control Reverse Osmosis Sink Reservoir and Vulture Treated Effluent Management Total Suspended Solid Water Quality Guideline for the Protection of Aquatic Life 52

54 APPENDIX A AIR QUALITY Sample Calculations Ambient Air Quality Sample Calculation of Reference Annual Air Quality Reference Levels for Hazardous Substances The reference annual air quality levels for certain hazardous substances (metals) were calculated from the Ontario Ministry of the Environment s (MOE) 24-hour Ambient Air Quality Criteria based on equation A1. The Ontario MOE criteria were used as there are no similar criteria provided by the Province of Saskatchewan or federal Ministry of the Environment for these substances. The criteria for sulphur dioxide and total suspended particulates were obtained from the Appendix of the Saskatchewan Clean Air Regulations. C o p t C t 1 Equation A1 o = 1 where: C o is the concentration of the longer time period (µg/m 3 ) C 1 is the concentration of the shorter time period (µg/m 3 ) t 0 is the longer time period t 1 is the shorter time period p is a constant, 0.28 (OMOE, 2009) Calculated reference annual air quality level for uranium in total suspended particulate = U TSP, 24-hr (t 24-hr /t annual ) p U TSP, annual = 0.3 µg/m 3 (24 hours /8760 hours) 0.28 = 0.06 µg/m 3 Table A1 summarizes the calculated reference annual air quality levels for the hazardous substances that were analyzed in this report. Table A2 provides a summary of the air quality criteria and standards and calculated reference annual air quality levels for hazardous substances in the Province of Quebec. Sample Calculation of Air Quality Reference Levels for Nuclear Substances The reference levels for nuclear substances were calculated based on a 0.1 msv exposure to members of the public. This introduces a factor of 10 safety factor compared to the 1 msv annual regulatory dose to members of the public. Equation A2 was used to calculate reference levels for nuclear substances. 53

55 D RL = DC inh IR reference Equation A2 where: RL is the calculated reference level (Bq/m3) D reference is the dose limit (Sv/year) DC inh is the inhalation dose coefficient (Sv/Bq) IR is the inhalation rate (m3/year) Reference levels were calculated assuming continuous exposure (8760 hours/year) and a standard inhalation rate (8400 m 3 /year). Further, the Type S (slow solubility) inhalation dose coefficients as recommended by ICRP 72 (ICRP, 1995) were used. These dose coefficients are the most restrictive and would result in conservative calculated reference levels. Calculated reference level for lead-210 RL = D reference / (DC inh IR) = ( Sv/year) / (( Sv/Bq) 8400 m 3 /year) = Bq/m 3 Table A.3 summarizes the reference levels for the nuclear substances that were analyzed in this report. Sample Calculation for the Conversion of the Uranium from µg/m 3 to Bq/m 3 The environmental monitoring data for uranium was collected as µg/m 3. Uranium may have both toxic and radiological effects. Therefore, in order to compare the annual averages to reference levels for nuclear substances, the concentration of uranium in µg/m 3 were converted to Bq/m 3 using equations A3. AU, nat = mu, nat F SA Equation A3 where A U,nat is the activity of natural uranium (Bq/m3) m U,nat is the mass of natural uranium (µg/m3) F is a conversion factor to convert from µg to mg SA is the specific activity of uranium (Bq/mg) Calculated activity of natural uranium from uranium in µg/m 3 A U, nat = m U,na F SA = ( µg/m 3 ) Bq/mg = Bq/m 3 54

56 The calculated activity of natural uranium was then used to calculate the activity of the main two isotopes of uranium, U-234 and U-238, as shown below by the sample calculation using Equation A4. AU, isotope = AU, nat IA Equation A4 where AU, isotope is the activity of one of the isotopes of uranium, U-234 and U-238 (Bq/m3). A U, nat is activity of natural uranium (Bq/m3). IA is the isotopic abundance of uranium. The isotopic abundance of U-234 and U-238 was assumed to be 48.86% for both isotopes. Calculated activity of U-238 from activity of natural uranium A U,isotope = A U, nat IA = ( Bq/m 3 ) = Bq/m 3 Sample Calculation for combined dose for all measured radionuclide from the high volume ambient air samplers. The annual inhalation dose for a given radionuclide (D) can be determined using equation A5: D = C DC V Equation A5 air inhalation where C air is the concentration of the in air (Bq m-3). DC inhalation is the adult dose coefficient (Sv/Bq) recommended by the International Commission on Radiological Protection (ICRP Publication 72) (Type S was conservatively assumed for the calculations in this report). V is the volume of air inhaled by an adult per year (8400 m3 year-1) recommended by the Canadian Standards Association (CSA N ). Progeny were considered when they had a noticeable contribution to the dose. For these cases, progeny were either assumed to be in equilibrium with the parent nuclear substance or concentrations for progeny were assumed to be a fraction of the parent nuclear substance. 55

57 Sample Calculation for the Calculation of Dose from Inhalation of Radon Progeny The average annual dose from radon progeny (D Rn ) can be determined using equation A6: D = C F 8766 T DC Equation A6 Rn Rn equilibrium Rn where: C Rn is the concentration of Rn-222 in air (Bq/m3) F equilibrium is the equilibrium factor between Rn-222 and its decay products (UNSCEAR recommends equilibrium factors of 0.4 indoor and 0.6 outdoor) 8766 is the average number of hours in a year T is the occupancy factor (80% indoor and 20% outdoor) DC Rn is the average effective dose coefficient of 9 nsv per (Bq h m-3) recommended by UNSCEAR Annual dose from indoor exposure to radon progeny The 95 th percentile radon concentration of 42.9 Bq/m -3 was used in the calculation below. D Rn, indoor = 42.9 Bq m hours/year 80% 9 nsv per (Bq h m -3 ) = 1.08 msv Therefore, the indoor annual dose from exposure to radon progeny assuming year-round occupancy within 2-10 km from a radon release point is 1.08 msv. Annual dose from outdoor exposure to radon progeny The 95 th percentile radon concentration of 42.9 Bq/m -3 was used in the calculation below D Rn, outdoor = 42.9 Bq m hours/year 20% 9 nsv per (Bq h m -3 ) = 0.41 msv Therefore, the outdoor annual dose from exposure to radon progeny assuming year-round occupancy within 2-10 km from a radon release point is 0.41 msv. 56

58 References ICRP, Age-dependent Doses to the Members of the Public from Intake of Radionuclides - Part 5 Compilation of Ingestion and Inhalation Coefficients. ICRP Publication 72. Ann. ICRP 26 (1). Ontario Ministry of the Environment, Air Dispersion Modelling Guideline for Ontario (Version 2.0), Province of Saskatchewan, The Clean Air Regulations Appendix, Province of Quebec, Clean Air Regulation. September 1, =2&file=%2F%2FQ_2%2FQ2R4_1_A.htm, accessed September 9, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), Effects of Ionizing Radiation Volume II: Scientific Annexes C, D and E UNSCEAR, Sources and Effects of Ionizing Radiation Volume I, Report to General Assembly, Scientific Annexes A and B

59 Air Quality Summary and Reference Value Tables Table A.1: Summary of statistics for air quality (2000- Analyte Mean SD (2000- SE (2000- n (based on raw data) nbdl (based on raw data) n (based on calculation of annual averages) Arsenic (µg/m 3 ) 1.82E E E E E-02 Cadmium (µg/m 3 ) 7.78E E E E E-03 Copper (µg/m 3 ) 5.82E E E E Lead (µg/m 3 ) 2.58E E E E E-02 Molybdenum (µg/m 3 ) 1.20E E E E E-03 Nickel (µg/m 3 ) 2.03E E E E E-02 Selenium (µg/m 3 ) 1.08E E E E E-04 Uranium (µg/m 3 ) 6.21E E E E E-02 Zinc (µg/m 3 ) E Sulphur Dioxide (µg/m 3 ) Total Suspended Particulate (µg/m 3 ) Lead-210 (Bq/m 3 ) 4.45E E E E E-03 Polonium-210 (Bq/m 3 ) 3.07E E E E E-03 Radium-226 (Bq/m 3 ) 5.74E E E E E-04 Thorium-230 (Bq/m 3 ) 6.14E E E E E-04 nbdl = number below analytical method detection limit SD = standard deviation SE = standard error N = number of samples Min Max 58

60 Table A.2: Summary of statistics for radon in air (2000- Facility Number Distance from source Mean (Bq/m 3 ) SD (Bq/m 3 ) SE (Bq/m 3 ) n Min (Bq/m 3 ) Max (Bq/m 3 ) Wheeler E N S W TE-J TE-J TE-J TE-J TE-J TE-J TE-J TE-J TE-M TE-M TE-M TE-M TE-M TE-M TE-M TE-M TE-S

61 TE-S TE-S TE-S TE-S TE-S TE-S TE-C McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ McArthur River AQ Rabbit RB BZ Rabbit RB BZ Rabbit RB BZ Rabbit EP Rabbit EP Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site

62 Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site Rabbit Wo Site

63 Table A.3: Ambient Air Quality Reference Level for Hazardous Substances using Province of Ontario and Province of Saskatchewan Air Quality Criteria Contaminant Units 24-hour Ambient Air Quality Criteria Reference Annual Air Quality Levels Reference Arsenic µg/m OMOE 2012 Cobalt µg/m OMOE 2012 Copper µg/m OMOE 2012 Lead µg/m OMOE 2012 Nickel (in TSP) µg/m OMOE 2012 Molybdenum µg/m OMOE 2012 Selenium µg/m OMOE 2012 Uranium (in TSP) µg/m OMOE 2012 Zinc µg/m OMOE 2012 Sulphur Dioxide µg/m Total Suspended Particulates µg/m Saskatchewan Clean Air Regulations Appendix Saskatchewan Clean Air Regulations Appendix 62

64 Table A.4: Province of Quebec ambient air quality criteria and standards for hazardous substances Contaminant Units Quebec 24-hour Ambient Air Quality Criteria Quebec Annual Air Quality Standard Arsenic µg/m 3 n/a Cobalt µg/m 3 n/a n/a Copper µg/m n/a Lead µg/m 3 n/a 0.10 Nickel (in TSP) µg/m n/a Molybdenum µg/m 3 n/a Reference Annual Air Quality Levels Reference nr Province of Quebec, 2014 n/a Province of Quebec, Province of Quebec, 2014 nr Province of Quebec, Province of Quebec, 2014 n/a n/a Province of Quebec, 2014 Selenium µg/m n/a n/a n/a Province of Quebec, Uranium n/a n/a n/a Province of Quebec, (in TSP) µg/m Province of Quebec, Zinc µg/m n/a Sulphur Dioxide µg/m Total Suspended Particulates µg/m n/a n/a not available nr calculation not required as there is an Annual Air Quality Standard 2014 nr Province of Quebec, Province of Quebec,

65 Table A.5: Ambient air quality reference level for nuclear substances. Nuclear Substance Units for the Reference Level Reference level based on 0.1 msv exposure U-234 Bq/m E-03 U-238 Bq/m E-03 Th-230 Bq/m E-04 Ra-226 Bq/m E-03 Pb-210 Bq/m E-03 Po-210 Bq/m E-03 64

66 APPENDIX B SURFACE WATER QUALITY Surface Water Quality Summary Tables Table B.1: Surface Water Quality Reference s/local Background Analyte Exposure/Reference Mean (2000- SD (2000- SE (2000- n nbdl Min Max Aluminum Reference 1.52E E E Ammonia Reference 7.53E E E Arsenic Reference 2.77E E E Barium Reference 4.23E E E Boron Reference 2.83E E E Cadmium Reference 2.92E E E Copper Reference 7.37E E E Hardness Reference 7.55E E E Lead Reference 1.02E E E Lead-210 Reference 1.19E E E Manganese Reference 4.37E E E Molybdenum Reference 9.92E E E Nickel Reference 8.59E E E Ph Reference 6.64E E E Polonium- 210 Reference 5.08E E E Radium-226 Reference 5.13E E E Selenium Reference 1.69E E E Thorium-230 Reference 5.90E E E TSS Reference 1.88E E E Uranium Reference 4.10E E E Vanadium Reference 4.01E E E Zinc Reference 2.49E E E

67 Table B.2: Uranium Surface Water Quality Facility ID Name Watershed McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald 2.1 McDonald McArthur River 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow McArthur River 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source direct linear (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

68 Facility ID Name Watershed Rabbit 3.1 WQ10E WQ11E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit McArthur River WQ12E Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source direct linear (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

69 Facility ID Name Watershed 3.3 Delta WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source direct linear (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E

70 Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

71 Facility ID Name Watershed Rabbit Rabbit Rabbit Rabbit McArthur River 3.1 WQ10E WQ11E WQ12E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

72 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) n nbdl Min Max E E E E E E E E E E E E E E E

73 Facility McArthur River McArthur River McArthur River ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Watershed McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

74 Facility Rabbit Rabbit Rabbit Rabbit McArthur River ID 3.1 WQ10E WQ11E WQ12E Name Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Watershed Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

75 Facility ID WQ14E WQ13E 3.2 Name Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E

76 Table B.3: Selenium Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River Rabbit WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Horseshoe Pond - Downstream from Weir3 (Effluent McDonald McDonald McDonald Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE ( E E E n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

77 Facility ID Name Watershed Rabbit Rabbit Rabbit McArthur River WQ10E WQ11E outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E WQ14E Below (flow metering actually at SG8) Delta Delta Outflow Kewen McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE ( E E E E E E n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

78 Facility ID Name Watershed WQ13E 3.2 Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE ( E E E n nbdl Min Max E E E Facility McArthur River McArthur River ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Watershed McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) E E E E E E E E E E E E E E E E E E n nbdl Min Max

79 Facility McArthur River Rabbit Rabbit Rabbit ID WQ10E WQ11E Name Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Watershed Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E n nbdl Min Max

80 Facility Rabbit McArthur River ID WQ12E WQ14E WQ13E 3.2 Name Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean ( ) SD( ) SE ( ) E E E E E E E E E E E E E E E E E E E E E E E E n nbdl Min Max

81 Facility McArthur River McArthur River McArthur River ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Watershed McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

82 Facility Rabbit Rabbit Rabbit Rabbit McArthur River ID 3.1 WQ10E WQ11E WQ12E Name Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Watershed Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

83 Facility ID WQ14E WQ13E 3.2 Name Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E

84 Table B.4: Molybdenum Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E E E E E E E E E E E-01 SE ( E E E E E E E E E E- 02 n nbdl Min Max E E E E E E E E E E E E E E E E E E E E-01 83

85 Facility ID Name Watershed Rabbit Rabbit Rabbit Rabbit McArthur River 3.1 WQ10E WQ11E WQ12E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E E E E E E E E E E E-02 SE ( E E E E E E E E E E- 03 n nbdl Min Max E E E E E E E E E E E E E E E E E E E E-02 84

86 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E-03 SE ( E E E E E- 03 n nbdl Min Max E E E E E E E E E E-03 85

87 Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E E E E E E E E E E E-01 SE ( E E E E E E E E E E- 02 n nbdl Min Max E E E E E E E E E E E E E E E E E E E E-01 86

88 Facility ID Name Watershed Rabbit Rabbit Rabbit Rabbit McArthur River 3.1 WQ10E WQ11E WQ12E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E E E E E E E E E E E-02 SE ( E E E E E E E E E E- 03 n nbdl Min Max E E E E E E E E E E E E E E E E E E E E-02 87

89 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E-03 SE ( E E E E E- 03 n nbdl Min Max E E E E E E E E E E-03 88

90 Facility McArthur River McArthur River McArthur River ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Watershed McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E-01 89

91 Facility Rabbit Rabbit Rabbit Rabbit McArthur River ID 3.1 WQ10E WQ11E WQ12E Name Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Watershed Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E-02 90

92 Facility ID WQ14E WQ13E 3.2 Name Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2010- SD (2010- SE (2010- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E+00 91

93 Table B.5: Aluminum Surface Water Quality Facility ID Name Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Horsefly Outflow McDonald E E E McArthur at Bridge Below Hydrometric River E E E Little McDonald McDonald E E E McDonald McDonald E E E McArthur Boomerang at Inflow from Muskeg River 2.3 Receiving Area E E E Wolf Outflow E E E McArthur River 3.3 Approx. 2km Downstream of Bridge Crossing E E E Yak Creek E E E E E E Rabbit 3.1 Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Horseshoe Creek E E E McDonald McDonald E E E

94 Facility ID Name Watershed Rabbit Rabbit Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Middle Pyrite Creek E E E Horseshoe 3.4 Hidden Bay Creek E E E Horseshoe Creek (Effluent Stream Prior Horseshoe 3.2 to Hidden Bay) Creek E E E Hidden Bay Near Horseshoe Creek Outlet Rabbit McArthur River 3.5 Little Yalowega 3.3 Delta Delta Outflow 3.2 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Horseshoe Creek E E E E E E E E E E E E E E E

95 Table B.6: Ammonia Surface Water Quality Facility ID Name Horsefly Outflow WQ09E Sink Reservoir at Bridge Below McArthur Hydrometric River 3.2 Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area McArthur River McArthur River 3.3 Wolf Outflow Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max McDonald E E E E E E E E E McDonald E E E McDonald E E E E E E E E E E E E E E E

96 Facility ID Name 3.8 WQ10E Vulture McDonald Middle Pyrite Creek WQ11E East Basin McArthur Little Yalowega River 3.5 Below (flow metering actually at SG8) WQ12E 3.3 Delta Delta Outflow WQ14E Kewen WQ13E Below Highway 905 Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E McDonald E E E E E E E E E E E E E E E E E E E E E E E E E E E

97 Facility ID 3.2 Name Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E

98 Table B.7: Arsenic Surface Water Quality Facility ID Name Watershed McArthur River WQ09E McArthur River Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald 2.1 McDonald McArthur River 3.3 Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

99 Facility ID Name Watershed Rabbit 3.1 Rabbit WQ10E WQ11E Rabbit 3.2 Rabbit McArthur River Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin 3.4 Hidden Bay WQ12E Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

100 Facility ID Name Watershed 3.3 Delta WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E

101 Table B.8: Barium Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE ( E E E n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E

102 Facility ID Name Watershed Rabbit 3.1 lake Rabbit WQ10E WQ11E Rabbit 3.2 Rabbit McArthur River lake Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin 3.4 Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

103 Facility ID Name Watershed lake lake WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E

104 Table B.9: Boron Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Rabbit 3.1 WQ10E WQ11E Sink Reservoir at Bridge Below Hydrometric Boomerang at Inflow from Muskeg Receiving Area Approx. 2km Downstream of Bridge Crossing Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture East Basin Rabbit 3.4 Hidden Bay Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E

105 Facility ID Name Watershed Rabbit 3.2 Rabbit WQ12E WQ14E WQ13E Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Below (flow metering actually at SG8) Kewen Below Highway 905 nbdl = number below analytical method detection limit. Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E

106 Table B.10: Cadmium Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

107 Facility ID Name Watershed Rabbit Rabbit Rabbit Rabbit McArthur River 3.1 WQ10E WQ11E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E 3.3 Below (flow metering actually at SG8) Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

108 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E Facility McArthur River ID WQ09E 3.2 Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Watershed McDonald Distance from Source - direct linear(km ) Distance from Source - Along Watershed (km) Mean ( E E E- 06 SD (2010- SE (2010- n nbdl Min Max Hardness -adjusted aq life guideline 1.43E E E E E E

109 Facility ID McArthur River McArthur River 3.3 Name Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 Watershed McDonald McDonald Distance from Source - direct linear(km ) Distance from Source - Along Watershed (km) Mean ( E E E E E E E- 05 SD (2010- SE ( E E E E E E n nbdl Min Max E E E E E E E E Hardness -adjusted aq life guideline

110 Facility ID Rabbit 3.1 Name Horseshoe Pond - Downstream from Weir3 (Effluent outlet) WQ10E Vulture WQ11E McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Watershed Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km ) Distance from Source - Along Watershed (km) Mean ( E E E E E E E E- 06 SD (2010- SE ( E E E E E E E E E E E E E E E E n nbdl Min Max Hardness -adjusted aq life guideline

111 Facility McArthur River ID 3.5 WQ12E Name Little Yalowega Collins Creek Below (flow metering actually at SG8) 3.3 Delta Delta Outflow WQ14E Kewen WQ13E 3.2 Collins Creek Below Highway 905 Wheeler River (Downstrea m of David Creek) nbdl = number below analytical method detection limit. Watershed Distance from Source - direct linear(km ) Distance from Source - Along Watershed (km) Mean ( E E E E E E E+0 0 SD (2010- SE ( E E E E E E n nbdl Min Max Hardness -adjusted aq life guideline E E E E E E E E

112 Table B.11: Copper Surface Water Quality Facility ID Name Watershed McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald 2.1 McDonald McArthur River McArthur River 3.3 Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

113 Facility ID Name Watershed Rabbit 3.1 WQ10E WQ11E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit McArthur River WQ12E Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Little Yalowega Below (flow metering actually at SG8) Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

114 Facility ID Name Watershed 3.3 Delta WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E

115 Table B.12: Lead Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

116 Facility ID Name Watershed Rabbit 3.1 Rabbit WQ10E WQ11E Rabbit 3.2 Rabbit McArthur River Horseshoe Pond Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin 3.4 Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

117 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E

118 Table B.13: Manganese Surface Water Quality Facility ID Name Watershed McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald McArthur River 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow McArthur River 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 Rabbit 3.1 Horseshoe Pond Downstream from Weir3 (Effluent outlet) McDonald McDonald McDonald Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

119 Facility ID Name Watershed WQ10E WQ11E Vulture McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit McArthur River Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta WQ14E Delta Outflow Kewen McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

120 Facility ID Name Watershed WQ13E 3.2 Below Highway 905 Wheeler River (Downstream of David Creek) nbdl = number below analytical method detection limit. Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E

121 Table B.14: Nickel Surface Water Quality Facility ID Name Watershed McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald McArthur River 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow McArthur River 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 Rabbit 3.1 Horseshoe Pond Downstream from Weir3 (Effluent outlet) McDonald McDonald McDonald Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

122 Facility ID Name Watershed WQ10E WQ11E Vulture McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit McArthur River Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta WQ14E WQ13E Delta Outflow Kewen Below Highway 905 McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

123 Facility ID Name Watershed 3.2 Wheeler River (Downstream of David Creek) nbdl = number below analytical method detection limit. Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E

124 Table B.15: Vanadium Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

125 Facility ID Name Watershed Rabbit 3.1 Rabbit WQ10E WQ11E Rabbit 3.2 Rabbit McArthur River Horseshoe Pond Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin 3.4 Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E-04 #DIV/0! #DIV/0! E E E E E E E E E

126 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E

127 Table B.16: Zinc Surface Water Quality Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 McDonald McDonald McDonald Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE ( E E E E E E E E E n nbd L Min Max E E E E E E E E E E E E E E E E E E E E E

128 Facility ID Name Watershed Rabbit 3.1 Rabbit WQ10E WQ11E Rabbit 3.2 Rabbit McArthur River Horseshoe Pond Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin 3.4 Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE ( E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E n nbd L Min Max E E E

129 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source Bird s Eye (km) Distance from Source Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbd L E E E E E E E E E Min Max E E E

130 Table B.17: Lead-210 Surface Water Quality Facility McArthur River McArthur River McArthur River Rabbit ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Watershed McDonald Collins Creek McDonald McDonald Horseshoe Creek Distance from Source Bird s Eye (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

131 Facility Rabbit Rabbit McArthur River ID WQ10E WQ11E Name Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) 3.5 Little Yalowega WQ12E WQ14E Below (flow metering actually at SG8) Delta Delta Outflow Kewen Watershed Collins Creek McDonald Collins Creek Horseshoe Creek Horseshoe Creek Collins Creek Collins Creek Distance from Source Bird s Eye (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

132 Facility ID WQ13E 3.2 Name Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed Collins Creek Distance from Source Bird s Eye (km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E

133 Table B.18: Polonium-210 Surface Water Quality Facility McArthur River McArthur River ID Name 3.5 Little Yalowega WQ12E WQ14E WQ13E WQ09E 3.2 Below (flow metering actually at SG8) Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Watershed Collins Creek Collins Creek Collins Creek McDonald Collins Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E-03 #DIV/0! #DIV/0! E E E E E E E E E

134 Facility McArthur River McArthur River Rabbit ID WQ10E WQ11E Name Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Watershed McDonald McDonald Horseshoe Creek Collins Creek McDonald Collins Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

135 Facility Rabbit Rabbit ID Name Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) nbdl = number below analytical method detection limit. Watershed Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E

136 Table B.19: Radium-226 Surface Water Quality Facility ID Name Watershed McArthur River WQ09E 3.2 Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric 2.0 Little McDonald 2.1 McDonald McArthur River 2.3 Boomerang at Inflow from Muskeg Receiving Area 4.0 Wolf Outflow McArthur River 3.3 Approx. 2km Downstream of Bridge Crossing 3.9 Yak Creek 3.8 Rabbit 3.1 Horseshoe Pond - Downstream from Weir3 (Effluent outlet) McDonald McDonald McDonald Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

137 Facility ID Name Watershed WQ10E WQ11E Vulture McDonald Middle Pyrite Creek East Basin Rabbit 3.4 Hidden Bay Rabbit 3.2 Rabbit McArthur River Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E Below (flow metering actually at SG8) 3.3 Delta WQ14E WQ13E Delta Outflow Kewen Below Highway 905 McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

138 Facility ID Name Watershed 3.2 Wheeler River (Downstream of David Creek) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E

139 Table B.20: Thorium-230 Surface Water Quality Facility McArthur River McArthur River ID Name 3.5 Little Yalowega WQ12E WQ14E WQ13E WQ09E Below (flow metering actually at SG8) Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald Watershed Collins Creek Collins Creek Collins Creek McDonald Collins Creek McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E-03 #DIV/0! #DIV/0! E E E E E E E E E E E E

140 Facility McArthur River McArthur River Rabbit Rabbit ID WQ10E WQ11E 3.4 Name McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Watershed McDonald Horseshoe Creek Collins Creek McDonald Collins Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

141 Facility Rabbit ID 3.2 Name Horseshoe Creek (Effluent Stream Prior to Hidden Bay) nbdl = number below analytical method detection limit. Watershed Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E

142 Table B.21: Hardness (Surface Water Quality) Facility ID Name Watershed McArthur River McArthur River McArthur River WQ09E Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek McDonald McDonald McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

143 Facility ID Name Watershed Rabbit Rabbit Rabbit Rabbit McArthur River 3.1 WQ10E WQ11E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin Hidden Bay Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet 3.5 Little Yalowega WQ12E 3.3 Below (flow metering actually at SG8) Delta Horseshoe Creek McDonald Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

144 Facility ID Name Watershed WQ14E WQ13E 3.2 Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E

145 Table B.22: ph (Surface Water Quality) Facility McArthur River McArthur River McArthur River ID WQ09E Name Horsefly Outflow Sink Reservoir at Bridge Below Hydrometric Little McDonald McDonald Boomerang at Inflow from Muskeg Receiving Area Wolf Outflow Approx. 2km Downstream of Bridge Crossing Yak Creek Watershed McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E-01 McDonald McDonald E E E E E E E E E E E E-01 SE ( E E E E E E E E E- 02 n nbdl Min Max

146 Facility ID 3.8 WQ10E WQ11E WQ12E WQ14E WQ13E 3.2 Name Vulture McDonald Middle Pyrite Creek East Basin Below (flow metering actually at SG8) Delta Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of ) nbdl = number below analytical method detection limit. Watershed McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD ( E E E E E E E E E E E E E E E E E E E E E E-01 SE ( E E E E E E E E E E E- 01 n nbdl Min Max

147 Table B.23: Total Suspended Solids (Surface Water Quality) Facility ID Name Watershed WQ09E Horsefly Outflow Sink Reservoir 2.0 Little McDonald 2.1 McDonald 4.0 Wolf Outflow 3.9 Yak Creek 3.8 Rabbit 3.1 WQ10E WQ11E Horseshoe Pond - Downstream from Weir3 (Effluent outlet) Vulture McDonald Middle Pyrite Creek East Basin McDonald McDonald McDonald Horseshoe Creek McDonald Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E

148 Facility ID Name Watershed Rabbit 3.4 Rabbit 3.2 Rabbit WQ12E Hidden Bay 3.3 Delta WQ14E WQ13E 3.2 Horseshoe Creek (Effluent Stream Prior to Hidden Bay) Hidden Bay Near Horseshoe Creek Outlet Below (flow metering actually at SG8) Delta Outflow Kewen Below Highway 905 Wheeler River (Downstream of David Creek) nbdl = number below analytical method detection limit. Horseshoe Creek Horseshoe Creek Horseshoe Creek Distance from Source - direct linear(km) Distance from Source - Along Watershed (km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max E E E E E E E E E E E E E E E E E E E E E E E E E E E

149 Surface Water Quality Figures Figure B Uranium Concentrations in Surface Waters Exposed to Treated Effluent from Operating Uranium Mines and Mills ( Concentration (mg/l) Drinking Water Quality Guideline Protection of Aquatic Life Guideline 0 Local Background Distance from Source (km) 148

150 Figure B.2 149

151 Figure B.3 150

152 Figure B.4 151

153 Figure B.5 152

154 Figure B.6 153

155 Figure B.7 154

156 Figure B.8 155

157 Figure B.9 156

158 FigureB

159 Figure B

160 Figure B

161 Figure B

162 Figure B

163 Figure B

164 Figure B

165 Figure B

166 Figure B

167 Figure B

168 Figure B

169 Figure B

170 Figure B

171 APPENDIX C CONCENTRATION IN FISH FLESH Sample Calculations Concentrations in Fish Flesh Sample Calculations Fish Toxicity Reference Values Fish toxicity reference values, TRV fish, (mg/g) represent the reference concentrations for hazardous substances in fish flesh in terms of their consumption by people. This provides an estimate of the potential exposure of a member of the public to a conservativelychosen country food diet of mainly fish. Fish were chosen for this type of screening for practical reasons, given the large set of fish flesh data for multiple COPCs. Measured as opposed to modelled data for other country foods (moose, caribou, waterfowl, etc.) are few. TRV values were calculated using equation C1. TRVhazard BW TRV fish = Equation C1 CR where: fish TRV hazard [mg/kg body weight/day] is the toxicity reference value (Health Canada, 2010; CanNorth, 2014) BW [kg] is the body weight associated with the five age ranges in Health Canada (2010) CR fish [g] is the fish consumption rate (CanNorth, 2000) The consumption rate was determined by taking the average of the maximum winter and maximum summer consumption rate, intake values were determined for each of the five age groups specified in the CanNorth survey; the most conservative adult receptor was ultimately used for calculation of the TRV fish. The CR fish value chosen was g per day; it is based on a maximum summer fish intake of g per day and a maximum winter fish intake of g per day for a year old male. The average consumption rate for an adult male is from the Hatchet survey was 208 g/d. This is very similar to the 220 g/day found in Richardson (1997) that is recommended by Health Canada (2004) as a value representing native Canadian diets high in fish. For the contaminants that have different TRV hazard values specified by Health Canada for the five age groups, the adult age group with the most conservative value was used. Sample Calculations Nuclear Substances Reference Fish Concentrations Following the logic of calculations for hazardous substances, reference fish concentrations (C fish ) for nuclear substances resulting in an annual dose of 0.1 msv were calculated for a country foods diet, using equation C2. 170

172 The regulatory dose limit to a member of the public is 1 msv per year. The use of one tenth of this value conservatively allows for intakes of other radionuclides in the uranium decay chain, and intakes from other pathways when examining just one diet item (fish) and one radionuclide at a time. Conceptually, the concentration C fish represents a screening tool to identify situations where a person could approach the public dose limit when pursuing a country foods diet focused mainly on fish, a common lifestyle in northern Canada with its many lakes. The calculation includes a safety factor of ten to accommodate uncertainties in modelling and summing the total intakes of COPCs from all sources. where: C fish = DC ingestion Dreference CR D reference [msv] is one tenth of the public dose limit (0.1 msv) fish Equation C2 DC ingestion [msv/bq] is the radionuclide and age specific ingestion dose coefficient from ICRP Publication [d] is the average number of days in a year CR fish [g] is the fish consumption rate (CanNorth, 2000) For the fish consumption rate CR fish, the maximum winter and maximum summer consumption rates were averaged for each age range in the CanNorth survey to select the most conservative value. An adult male receptor had the highest value and was used to derive C fish. Specifically, a rate of g/d was chosen by averaging the maximum rates for year-old men of g/d in summer and g/d in winter. This represents a large amount of fish as the meat portion of one s diet; on average both sexes in the three age groups consumed g/d of fish. References CanNorth: Canada North Environmental Services, Hatchet Dietary Survey Final Report, March Prepared for the Atomic Energy Control Board, Project S:274. CanNorth: Canada North Environmental Services, 2014a. Eastern Athabasca Region Monitoring Program 2012 Community Report. Health Canada, 2010, Part II: Health Canada Toxicological Reference Values (TRVs) and Chemical-Specific Factors, Version 2.0, and Appendix A of Part II: Health Canada Toxicological Reference Values (TRVs) and Chemical-Specific Factors, Version 2.0 ICRP: International Commission on Radiological Protection, Age-dependent Doses to the Members of the Public from Intake of Radionuclides - Part 5 Compilation of Ingestion and Inhalation Coefficients. ICRP Publication 72. Annals of the ICRP 26 (1). 171

173 172

174 Concentration in Fish Flesh Summary Tables Table C.1: Local Background fish flesh concentrations Analyte Mean (2000- SD (2000- SE (2000- n nbdl Min Max Arsenic 2.57E E E Cadmium 1.74E E E Copper 2.20E E E Lead 2.16E E E Manganese 1.74E E E Molybdenum 9.25E E E Nickel 1.26E E E Selenium 3.39E E E Uranium 2.46E E E Zinc 5.49E E E Lead E E E Polonium E E E E Radium E E E Thorium E E E Metal Concentrations in µg/g ww; radionuclide concentrations in Bq/g ww. nbdl = number of samples below detection level 173

175 Table C.2: Arsenic concentrations in fish flesh Study Area Waterbody Distance From Source Mean (2000- SD (2000- SE (2000- n nbdl Min Max (linear km) Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 174

176 Table C.3: Cadmium concentrations in fish flesh Distance From Study Area Waterbody Source Mean (2000- SD (2000- SE (2000- n nbdl Min Max (linear km) Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 175

177 Table C.4: Copper concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 176

178 Table C.5: Lead concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 177

179 Table C.6: Manganese concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 178

180 Table C.7: Molybdenum concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 179

181 Table C.8: Nickel concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 180

182 Table C.9: Selenium concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 181

183 Table C.10: Uranium concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 182

184 Table C.11: Zinc concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Concentrations in µg/g ww nbdl = number of samples below detection level 183

185 Table C.12: Lead-210 concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Russell E E E Concentrations in Bq/g ww nbdl = number of samples below detection level 184

186 Table C.13: Polonium-210 concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Russell E E E Concentrations in Bq/g ww nbdl = number of samples below detection level 185

187 Table C.14: Radium-226 concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E McArthur River East Boomerang E E E McDonald E E E Vulture E E E McArthur River Little Yalowega E E E Rabbit Hidden Bay E E E Upper Delta E E E Delta E E E Kewen E E E Russell E E E Concentrations in Bq/g ww nbdl = number of samples below detection level 186

188 Table C.15: Thorium-230 concentrations in fish flesh Study Area Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Sink Reservoir E E E E McArthur River East Boomerang E E E E McDonald E E E E Vulture E E E E McArthur River Little Yalowega E E E E Rabbit Hidden Bay E E E E Delta E E E E Kewen E E E E Russell E E E E Concentrations in Bq/g ww nbdl = number of samples below detection level 187

189 Concentration in Fish Flesh Figures Figure C.1 188

190 Figure C.2 189

191 Figure C.3 190

192 Figure C.4 191

193 Figure C.5 192

194 Figure C.6 193

195 Figure C.7 194

196 Figure C.8 195

197 Figure C.9 196

198 Figure C

199 Figure C

200 Figure C

201 Figure C

202 Figure C

203 APPENDIX D SEDIMENT QUALITY Sediment Quality Summary Tables Table D.1: Local Background Sediment concentrations Analyte Mean (2000- SD (2000- SE (2000- n nbdl Min Max Arsenic 6.69E E E Cadmium 4.43E E E Copper 4.61E E E Lead 8.00E E E Manganese 8.73E E E Molybdenum 5.21E E E Nickel 9.14E E E Selenium 8.80E E E Uranium 6.37E E E Zinc 4.03E E E Lead E E E Polonium E E E Radium E E E Thorium E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 202

204 Table D.2: Arsenic sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 203

205 Table D.3: Cadmium sediment concentrations Facility Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 204

206 Table D.4: Copper sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 205

207 Table D.5: Lead sediment concentrations Facility Waterbody Distance From Source (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 206

208 Table D.6: Manganese sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 207

209 Table D.7: Molybdenum sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 208

210 Table D.8: Nickel sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 209

211 Table D.9: Selenium sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 210

212 Table D.10: Uranium sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 211

213 Table D.11: Zinc sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 212

214 Table D.12: Lead-210 sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 213

215 Table D.13: Polonium-210 sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 214

216 Table D.14: Radium-226 sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max Delta E E E Little McDonald E E E McDonald E E E Fox (KL) E E E McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 215

217 Table D.15: Thorium-230 sediment concentrations Distance From Source Facility Waterbody (linear km) Mean (2000- SD (2000- SE (2000- n nbdl Min Max McArthur River East Boomerang E E E McArthur River Little Yalowega E E E Kewen E E E Sink Reservoir E E E Vulture E E E Rabbit Hidden Bay Deep E E E Rabbit Hidden Bay Shallow E E E Rabbit Horseshoe Pond E E E Metal Concentrations in µg/g dw; radionuclide concentrations in Bq/g dw. nbdl = number of samples below detection level 216

218 Sediment Quality Figures Figure D.1 217

219 Figure D.2 218

220 Figure D.3 219

221 Figure D.4 220

222 Figure D.5 221

223 Figure D.6 222

224 Figure D.7 223

225 Figure D.8 224

226 Figure D.9 225

227 Figure D

228 Figure D

229 Figure D

230 Figure D

231 Figure D