Environment & Safety

Safety

We manage the safety of our workers through programs, systems, and standards, with our Safety, Health, Environment and Quality (SHEQ) Policy providing overarching guidance. There are many aspects of the management system that contribute to a safe work environment, a few examples include:

  • Risk assessments help identify issues and determine the appropriate controls; the corrective action process verifies that incidents and near misses are reported, tracked, investigated and shared with colleagues; and emergency preparedness and planning prepare us to respond to serious incidents.
  • We have developed 12 corporate safety standards to help protect our workers from our most common hazards. Some standards guide our general safety practices, such as our job hazard analysis and our job task observation, and other standards deal with specific hazardous situations (similar to other companies’ life saving rules): such as fall protection, confined space entry, rigging and hoisting, and control of hazardous energy (also referred to as lockout/tagout).
  • Routine audits are conducted to monitor compliance with regulations and our own requirements. These and other aspects of the management system are routinely examined to verify that they continue to be effective at keeping our workers safe.

Radiation Protection

Radiation risks are effectively managed at McArthur River and Key Lake. Each operation has a formal radiation protection program and dedicated personnel who ensure that doses to workers are as low as reasonably achievable. The programs require that radiation protection is considered in the physical design of all facilities and operating procedures. They also provide for systematic monitoring of radiation in work areas and track exposures of individual workers using a combination of monitoring devices and health testing. Radiation exposures at McArthur River and Key Lake are far below below the regulated limits.

Environmental Protection

At Cameco, protection of the environment is one of our highest corporate priorities during all stages of our activities, from exploration through development, operations, decommissioning, and reclamation.

We monitor our performance by tracking corporate and site-specific key performance indicators, conducting environmental monitoring programs, and regularly auditing our adherence to the requirements of these programs We use the information from all of our programs to help us to identify opportunities to improve.

Environmental management system

We have a ISO 14001-certified environmental management system used across our operating sites, which is supported by a corporate Environmental Management Program that outlines the operating requirements sites must meet. Our environmental management system encourages and promotes continuous adaptation of our practices based on new information and technologies.

Environmental risk assessments

We complete environmental risk assessments to systematically identify, quantify, and to characterize the potential risks to the environment, workers, and the public. We use our environmental risk assessments to inform our decisions and actions. Additionally, we complete an iterative process, where required, to verify that our proposed measures to protect the environment and the public are effective. We review or update the assessments every five years, incorporating results from our environmental monitoring programs and other scientific advances.

Environmental performance reports

For our Saskatchewan operations, every five years we also compare monitoring data collected during the reporting period against predictions contained in approved environmental risk assessments or environmental assessments. By reviewing the data from the performance reports and conducting risks assessments, we are able to demonstrate that human health and the environment in the vicinity of our Saskatchewan operations remains protected. Results from these analyses are also used to inform changes to the environmental monitoring programs conducted at each operation.

Corrective action process

We have a corrective action process in place to systematically investigate and address the causes of non-conformance to regulatory requirements or internal standards. The process includes classifying the non-conformance, assigning the appropriate level of investigation (dependent on incident significance), and tracking the recommended corrective actions to prevent and mitigate similar occurrences.

Audits

To support our culture of continuous improvement, our processes and operations undergo regular audits, including:

  • Our environmental management system is audited by a third-party every three years as a requirement to maintain our ISO 14001 certification.
  • Our SHEQ team conducts an internal audit of our SHEQ programs on a three-year cycle. The total audit scope is split in half and executed on a rotating basis. This means that all our sites undergo at least two audits to cover all aspects of our SHEQ programs within every three-year period. The audit follows the ISO 19001 process and encompasses our environmental and safety programs.
  • We also maintain and implement an internal audit program at our corporate office. Results and recommendations from this systematic and documented process are presented to senior management, who are responsible for implementing them and correcting any deficiencies. The internal audit group reports to the audit and finance committee of the board.

Environmental Monitoring

Comprehensive monitoring programs are in place at the McArthur River and Key Lake operations to help ensure that the surrounding environment is protected. Samples of water, air, soil, plants and fish are collected from numerous locations around the sites and tested to confirm that environmental protection systems are effective. Monitoring results are submitted to federal and provincial regulatory authorities for review. Cameco also supports independent regional monitoring downstream of its Saskatchewan operations to ensure there are no cumulative effects on the regional watershed. The extensive monitoring undertaken at McArthur River and Key Lake has identified no significant impact on the surrounding environment.

McArthur River Monitoring Results
Treated Water Quality — Arsenic

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan0.30.0001
22-Feb0.30.0001
22-Mar0.30.0001
22-Apr0.30.0001
22-May0.30.0001
22-Jun0.30.0001
22-Jul0.30.0001
22-Aug0.30.0001
22-Sep0.30.0001
22-Oct0.30.0001
22-Nov0.30.0001
22-Dec0.30.0001
23-Jan0.30.0002
23-Feb0.30.0003
23-Mar0.30.0004
23-Apr0.30.0002
23-May0.30.0004
23-Jun0.30.0003
23-Jul0.30.0001
23-Aug0.30.0002
23-Sep0.30.0002
23-Oct0.30.0001
23-Nov0.30.0002
23-Dec0.30.0002
 

Key Lake Monitoring Results
Treated Water Quality — Arsenic

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan0.30.0015
22-Feb0.30.0009
22-Mar0.30
22-Apr0.30
22-May0.30
22-Jun0.30
22-Jul0.30
22-Aug0.30.0025
22-Sep0.30.0011
22-Oct0.30.0032
22-Nov0.30.0025
22-Dec0.30.0014
23-Jan0.30.0014
23-Feb0.30.0026
23-Mar0.30.002
23-Apr0.30.0018
23-May0.30.0015
23-Jun0.30.0019
23-Jul0.30.0021
23-Aug0.30.0049
23-Sep0.30.0060
23-Oct0.30.0062
23-Nov0.30.0054
23-Dec0.30.0040
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Copper

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan0.30.0004
22-Feb0.30.0006
22-Mar0.30.0005
22-Apr0.30.0005
22-May0.30.0004
22-Jun0.30.0003
22-Jul0.30.0005
22-Aug0.30.0012
22-Sep0.30.0008
22-Oct0.30.0009
22-Nov0.30.0007
22-Dec0.30.0008
23-Jan0.30.001
23-Feb0.30.0008
23-Mar0.30.0009
23-Apr0.30.0023
23-May0.30.0006
23-Jun0.30.0007
23-Jul0.30.0006
23-Aug0.30.0006
23-Sep0.30.0004
23-Oct0.30.0005
23-Nov0.30.0005
23-Dec0.30.0004
 

Key Lake Monitoring Results
Treated Water Quality — Copper

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan0.30.0005
22-Feb0.30.0003
22-Mar0.30
22-Apr0.30
22-May0.30
22-Jun0.30
22-Jul0.30
22-Aug0.30.0013
22-Sep0.30.0008
22-Oct0.30.0018
22-Nov0.30.0036
22-Dec0.30.0022
23-Jan0.30.0037
23-Feb0.30.0069
23-Mar0.30.0042
23-Apr0.30.0034
23-May0.30.0067
23-Jun0.30.0048
23-Jul0.30.0029
 
23-Aug0.30.0021
23-Sep0.30.0040
23-Oct0.30.0060
23-Nov0.30.0068
23-Dec0.30.0068
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Lead

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan0.10.0001
22-Feb0.10.0001
22-Mar0.10.0001
22-Apr0.10.0001
22-May0.10.0001
22-Jun0.10.0001
22-Jul0.10.0001
22-Aug0.10.0001
22-Sep0.10.0001
22-Oct0.10.0001
22-Nov0.10.0001
22-Dec0.10.0001
23-Jan0.10.0001
23-Feb0.10.0002
23-Mar0.10.0001
23-Apr0.10.0001
23-May0.10.0001
23-Jun0.10.0001
23-Jul0.10.0001
23-Aug0.10.0001
23-Sep0.10.0001
23-Oct0.10.0001
23-Nov0.10.0001
23-Dec0.10.0001
 

Key Lake Monitoring Results
Treated Water Quality — Lead

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan0.10.0021
22-Feb0.10.0006
22-Mar0.10
22-Apr0.10
22-May0.10
22-Jun0.10
22-Jul0.10
22-Aug0.10.0005
22-Sep0.10.0006
22-Oct0.10.0003
22-Nov0.10.0002
22-Dec0.10.0001
23-Jan0.10.0001
23-Feb0.10.0001
23-Mar0.10.0001
23-Apr0.10.0002
23-May0.10.0001
23-Jun0.10.0001
23-Jul0.10.0001
23-Aug0.10.0001
23-Sep0.10.0001
23-Oct0.10.0001
23-Nov0.10.0002
23-Dec0.10.0002
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Nickel

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan0.50.0032
22-Feb0.50.0016
22-Mar0.50.0013
22-Apr0.50.002
22-May0.50.0017
22-Jun0.50.0016
22-Jul0.50.0012
22-Aug0.50.0017
22-Sep0.50.0017
22-Oct0.50.0031
22-Nov0.50.0036
22-Dec0.50.0027
23-Jan0.50.0021
23-Feb0.50.0018
23-Mar0.50.0017
23-Apr0.50.0028
23-May0.50.0012
23-Jun0.50.0011
23-Jul0.50.0008
23-Aug0.50.0008
23-Sep0.50.0010
23-Oct0.50.0010
23-Nov0.50.0013
23-Dec0.50.0012
 

Key Lake Monitoring Results
Treated Water Quality — Nickel

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan0.50.0844
22-Feb0.50.03
22-Mar0.50
22-Apr0.50
22-May0.50
22-Jun0.50
22-Jul0.50
22-Aug0.50.116
22-Sep0.50.1185
22-Oct0.50.0665
22-Nov0.50.053
22-Dec0.50.0575
23-Jan0.50.0456
23-Feb0.50.0285
23-Mar0.50.0365
23-Apr0.50.136
23-May0.50.0838
23-Jun0.50.087
23-Jul0.50.0900
23-Aug0.50.0750
23-Sep0.50.0570
23-Oct0.50.0636
23-Nov0.50.0368
23-Dec0.50.0340
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Zinc

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan0.50.0027
22-Feb0.50.0016
22-Mar0.50.0011
22-Apr0.50.0016
22-May0.50.0012
22-Jun0.50.0021
22-Jul0.50.0015
22-Aug0.50.0026
22-Sep0.50.0024
22-Oct0.50.0021
22-Nov0.50.0035
22-Dec0.50.0024
23-Jan0.50.0024
23-Feb0.50.0038
23-Mar0.50.0026
23-Apr0.50.0054
23-May0.50.0021
23-Jun0.50.0034
23-Jul0.50.0052
23-Aug0.50.0035
23-Sep0.50.0015
23-Oct0.50.0016
23-Nov0.50.0016
23-Dec0.50.0020
 

Key Lake Monitoring Results
Treated Water Quality — Zinc

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan0.50.0042
22-Feb0.50.0027
22-Mar0.50
22-Apr0.50
22-May0.50
22-Jun0.50
22-Jul0.50
22-Aug0.50.0048
22-Sep0.50.0052
22-Oct0.50.0045
22-Nov0.50.0031
22-Dec0.50.002
23-Jan0.50.0019
23-Feb0.50.0018
23-Mar0.50.0027
23-Apr0.50.0034
23-May0.50.0032
23-Jun0.50.0045
23-Jul0.50.0037
23-Aug0.50.0024
23-Sep0.50.0020
23-Oct0.50.0029
23-Nov0.50.0024
23-Dec0.50.0036
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Suspended Solids

 Metal and Diamond Mining Effluent Regulations (mg/L)McArthur River Level (mg/L)
22-Jan151
22-Feb151
22-Mar151
22-Apr151
22-May151
22-Jun151
22-Jul151
22-Aug151
22-Sep151
22-Oct151
22-Nov151
22-Dec151
23-Jan151
23-Feb151
23-Mar151
23-Apr151
23-May151
23-Jun151
23-Jul151
23-Aug151
23-Sep151
23-Oct151
23-Nov151
23-Dec151
 

Key Lake Monitoring Results
Treated Water Quality — Suspended Solids

 Metal and Diamond Mining Effluent Regulations (mg/L)Key Lake Level (mg/L)
22-Jan151
22-Feb152
22-Mar150
22-Apr150
22-May150
22-Jun150
22-Jul150
22-Aug152
22-Sep152
22-Oct152
22-Nov154
22-Dec153
23-Jan154
23-Feb155
23-Mar154
23-Apr154
23-May152
23-Jun152
23-Jul154
23-Aug152
23-Sep152
23-Oct151
23-Nov154
23-Dec154
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Radium-226

 Metal and Diamond Mining Effluent Regulations (Bq/L)McArthur River Level (Bq/L)
22-Jan0.370.023
22-Feb0.370.02
22-Mar0.370.02
22-Apr0.370.013
22-May0.370.018
22-Jun0.370.028
22-Jul0.370.028
22-Aug0.370.036
22-Sep0.370.023
22-Oct0.370.024
22-Nov0.370.035
22-Dec0.370.04
23-Jan0.370.05
23-Feb0.370.068
23-Mar0.370.073
23-Apr0.370.045
23-May0.370.048
23-Jun0.370.1
23-Jul0.370.074
23-Aug0.370.043
23-Sep0.370.025
23-Oct0.370.038
23-Nov0.370.045
23-Dec0.370.040
 

Key Lake Monitoring Results
Treated Water Quality — Radium-226

 Metal and Diamond Mining Effluent Regulations (Bq/L)Key Lake Level (Bq/L)
22-Jan0.370.04
22-Feb0.370.01
22-Mar0.370
22-Apr0.370
22-May0.370
22-Jun0.370
22-Jul0.370
22-Aug0.370.009
22-Sep0.370.015
22-Oct0.370.015
22-Nov0.370.014
22-Dec0.370.013
23-Jan0.370.009
23-Feb0.370.006
23-Mar0.370.009
23-Apr0.370.01
23-May0.370.006
23-Jun0.370.009
23-Jul0.370.010
23-Aug0.370.007
23-Sep0.370.006
23-Oct0.370.011
23-Nov0.370.011
23-Dec0.370.009
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — pH

 Authorized Maximum pHMcArthur River Level pHAuthorized Minimum pH
22-Jan9.57.46
22-Feb9.57.56
22-Mar9.57.56
22-Apr9.57.46
22-May9.57.66
22-Jun9.57.56
22-Jul9.57.56
22-Aug9.57.56
22-Sep9.57.56
22-Oct9.57.36
22-Nov9.57.26
22-Dec9.57.36
23-Jan9.57.36
23-Feb9.57.56
23-Mar9.57.36
23-Apr9.57.16
23-May9.57.16
23-Jun9.57.16
23-Jul9.57.66
23-Aug9.57.26
23-Sep9.57.26
23-Oct9.57.46
23-Nov9.57.16
23-Dec9.57.06
 

Key Lake Monitoring Results
Treated Water Quality — pH

 Authorized Maximum pHKey Lake Level pHAuthorized Minimum pH
22-Jan9.57.16
22-Feb9.56.96
22-Mar9.506
22-Apr9.506
22-May9.506
22-Jun9.506
22-Jul9.506
22-Aug9.56.96
22-Sep9.576
22-Oct9.57.36
22-Nov9.57.56
22-Dec9.57.36
23-Jan9.57.26
23-Feb9.56.96
23-Mar9.57.16
23-Apr9.57.46
23-May9.57.26
23-Jun9.576
23-Jul9.56.96
23-Aug9.57.26
23-Sep9.56.96
23-Oct9.56.96
23-Nov9.57.16
23-Dec9.57.06
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Selenium

 Saskatchewan Ministry of Environment Limit (mg/L)McArthur River Level (mg/L)
22-Jan0.60.0002
22-Feb0.60.0003
22-Mar0.60.0003
22-Apr0.60.0002
22-May0.60.0003
22-Jun0.60.0003
22-Jul0.60.0003
22-Aug0.60.0004
22-Sep0.60.0004
22-Oct0.60.0008
22-Nov0.60.0013
22-Dec0.60.0025
23-Jan0.60.0015
23-Feb0.60.0031
23-Mar0.60.0039
23-Apr0.60.0016
23-May0.60.0035
23-Jun0.60.0047
23-Jul0.60.0009
 
23-Aug0.60.0085
23-Sep0.60.0072
23-Oct0.60.0098
23-Nov0.60.0079
23-Dec0.60.0054
 

Key Lake Monitoring Results
Treated Water Quality — Selenium

 Saskatchewan Ministry of Environment Limit (mg/L)Key Lake Level (mg/L)
22-Jan0.60.0097
22-Feb0.60.0099
22-Mar0.60
22-Apr0.60
22-May0.60
22-Jun0.60
22-Jul0.60
22-Aug0.60.0088
22-Sep0.60.0086
22-Oct0.60.0086
22-Nov0.60.0082
22-Dec0.60.0096
23-Jan0.60.0096
23-Feb0.60.0117
23-Mar0.60.0116
23-Apr0.60.0084
23-May0.60.0132
23-Jun0.60.013
23-Jul0.60.0145
23-Aug0.60.0120
23-Sep0.60.0210
23-Oct0.60.0230
23-Nov0.60.0230
23-Dec0.60.0270
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Uranium

 Saskatchewan Ministry of Environment Limit (mg/L)McArthur River Level (mg/L)
22-Jan2.50.0184
22-Feb2.50.0175
22-Mar2.50.0121
22-Apr2.50.0083
22-May2.50.0094
22-Jun2.50.0048
22-Jul2.50.0024
22-Aug2.50.0095
22-Sep2.50.0064
22-Oct2.50.0179
22-Nov2.50.0054
22-Dec2.50.0139
23-Jan2.50.0092
23-Feb2.50.0309
23-Mar2.50.0072
23-Apr2.50.0105
23-May2.50.0042
23-Jun2.50.003
23-Jul2.50.0020
23-Aug2.50.0020
23-Sep2.50.0032
23-Oct2.50.0050
23-Nov2.50.0088
23-Dec2.50.0079
 

Key Lake Monitoring Results
Treated Water Quality — Uranium

 Saskatchewan Ministry of Environment Limit (mg/L)Key Lake Level (mg/L)
22-Jan2.50.0181
22-Feb2.50.0099
22-Mar2.50
22-Apr2.50
22-May2.50
22-Jun2.50
22-Jul2.50
22-Aug2.50.0205
22-Sep2.50.0304
22-Oct2.50.0433
22-Nov2.50.0346
22-Dec2.50.0078
23-Jan2.50.0061
23-Feb2.50.0046
23-Mar2.50.0029
23-Apr2.50.0175
23-May2.50.0013
23-Jun2.50.0015
23-Jul2.50.0007
23-Aug2.50.0022
23-Sep2.50.0016
23-Oct2.50.0026
23-Nov2.50.0035
23-Dec2.50.0016
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Treated Water Quality — Molybdenum

 McArthur River Level (mg/L)
22-Jan0.0027
22-Feb0.0116
22-Mar0.0046
22-Apr0.0037
22-May0.012
22-Jun0.007
22-Jul0.0077
22-Aug0.0149
22-Sep0.0198
22-Oct0.0456
22-Nov0.083
22-Dec0.064
23-Jan0.0688
23-Feb0.1705
23-Mar0.1325
23-Apr0.1646
23-May0.1883
23-Jun0.1205
23-Jul0.0614
23-Aug0.1066
23-Sep0.1088
23-Oct0.0777
23-Nov0.0873
23-Dec0.1120
 

Key Lake Monitoring Results
Treated Water Quality — Molybdenum

 Key Lake Level (mg/L)
22-Jan0.0035
22-Feb0.0016
22-Mar0
22-Apr0
22-May0
22-Jun0
22-Jul0
22-Aug0.0282
22-Sep0.0052
22-Oct0.0153
22-Nov0.0153
22-Dec0.0096
23-Jan0.0363
23-Feb0.0282
23-Mar0.0647
23-Apr0.0714
23-May0.0352
23-Jun0.0720
23-Jul0.0520
23-Aug0.0507
23-Sep0.0538
23-Oct0.0450
23-Nov0.0835
23-Dec0.6450
 

McArthur River Monitoring Results
Treated Water Quality — Un-ionized Ammonia as Nitrogen

 Metal and Diamond Mining Effluent Regulations (mg/L) McArthur River Level (mg/L)
22-Jan0.50.01
22-Feb0.50.01
22-Mar0.50.01
22-Apr0.50.01
22-May0.50.01
22-Jun0.50.01
22-Jul0.50.01
22-Aug0.50.01
22-Sep0.50.01
22-Oct0.50.01
22-Nov0.50.01
22-Dec0.50.01
23-Jan0.50.01
23-Feb0.50.01
23-Mar0.50.01
23-Apr0.50.01
23-May0.50.01
23-Jun0.50.01
23-Jul0.50.01
23-Aug0.50.01
23-Sep0.50.01
23-Oct0.50.01
23-Nov0.50.01
23-Dec0.50.01
 

Key Lake Monitoring Results
Treated Water Quality — Un-ionized Ammonia as Nitrogen

 Metal and Diamond Mining Effluent Regulations (mg/L) Key Lake Level (mg/L)
22-Jan0.50.01
22-Feb0.50.01
22-Mar0.50
22-Apr0.50
22-May0.50
22-Jun0.50
22-Jul0.50
22-Aug0.50.01
22-Sep0.50.01
22-Oct0.50.01
22-Nov0.50.02
22-Dec0.50.03
23-Jan0.50.03
23-Feb0.50.03
23-Mar0.50.03
23-Apr0.50.11
23-May0.50.08
23-Jun0.50.08
23-Jul0.50.07
23-Aug0.50.04
23-Sep0.50.02
23-Oct0.50.02
23-Nov0.50.03
23-Dec0.50.02
 

NOTE: No reporting for Mar-Jul 2022 as facility down for scheduled maintenance.

McArthur River Monitoring Results
Ambient Air Quality – Annual Average Total Suspended Particulate (TSP)    

 Saskatchewan Ministry of Environment Standard - see note (µg/m³)Annual Average (µg/m³)
2012707.2
2013704.9
2014704.2
2015704.2
2016602.3
2017603.2
2018601.7
2019601.4
2020601.1
2021602.2
2022602.7
2023607.4
 

NOTE - Regulations replaced and standard revised on June 1, 2015; however for consistency, the old value is referenced for the 2015 reporting year. Reporting against the new value began in Q1 2016.

Key Lake Monitoring Results
Ambient Air Quality – Annual Average Total Suspended Particulate (TSP)  

 Saskatchewan Ministry of Environment Standard - see note (µg/m³)Annual Average (µg/m³)
20127011.5
20137010.4
20147010.3
20157010
20166010.8
20176012.2
2018608.8
2019606.7
2020605.9
2021606.9
2022606.4
2023606.3
 

NOTE - Regulations replaced and standard revised on June 1, 2015; however for consistency, the old value is referenced for the 2015 reporting year. Reporting against the new value began in Q1 2016.

Key Lake Monitoring Results
Ambient Air Quality – Annual Average Ambient Sulfur Dioxide (SO₂) 

 Saskatchewan Ministry of Environment Standard (ppb)Annual Average (ppb)
2012107.7
2013106.7
2014107.3
2015109.1
201680.5
201780.4
201880
201980
202080
202180
202280
202382.8
 

NOTE - Regulations replaced and standard revised on June 1, 2015; however for consistency, the old value is referenced for the 2015 reporting year. Reporting against the new value began in Q1 2016. During Care and Maintenance, the plant was shut down, therefore no emissions were reported.

 

Environmental Incidents and Other Events

Environmental incidents and other events are reported to regulatory agencies as required by federal and provincial regulations.

Latest incidents or events:

 

DateApril 22, 2024
IncidentReportable Release
DetailsOn April 22, 2024, approximately 40 m3 of treated effluent was released as a result of a liner tear in a monitoring pond. Lab analysis completed confirmed the water was of good quality and met regulatory limits for release to the environment.
Corrective ActionThe pond has been drained and the liner will be repaired by trained personnel.
Environmental Effectno measurable impact to the environment1

 

 

Past reporting

McArthur River

DateApril 22, 2024
IncidentReportable Release
DetailsOn April 22, 2024, approximately 40 m3 of treated effluent was released as a result of a liner tear in a monitoring pond. Lab analysis completed confirmed the water was of good quality and met regulatory limits for release to the environment.
Corrective ActionThe pond has been drained and the liner will be repaired by trained personnel.
Environmental Effectno measurable impact to the environment1
DateApril 7, 2024
IncidentEmergency transport to external medical facilities
DetailsThe emergency response team (ERT) was activated to respond to a non-occupational medical emergency for an underground worker. The worker was taken to the health centre for assessment and treatment. While the ERT was activated, the team assisted a second worker who received an injury to their face while observing a coworker operating a handheld hammer drill.
Corrective ActionThe ERT helped both workers report to the on-site health centre. Both workers were sent off-site by air ambulance for additional medical assessment.
Environmental Effectnot applicableN/A
DateMarch 7, 2024
IncidentRadiation Action Level Exceedance
DetailsRegular monitoring determined the dose for two workers had exceeded the weekly action level. The quarterly dose estimate for one of the workers also exceeds the quarterly action level.  The annual dose estimates for both workers are well below the regulatory limit.
Corrective ActionPreliminary investigation suggests that the exposure may be linked to completing multiple manual measurements of the elevation of the concrete while backfilling a production raise underground. The site is investigating the procedure for this task to ensure it is being performed consistent with the As Low As Reasonably Achievable (ALARA) principle.
Environmental Effectnot applicableN/A
DateDecember 11-12, 2023
IncidentDangerous Occurrence / Lost-Time Injury
DetailsOn December 11, 2023, a worker was operating a scoop by remote control from a crosscut in a waste pass on the 640L. There was a run of muck when material hung up in the waste pass released, which pressed up onto and moved the scoop. The worker turned to further retreat into the crosscut, tripped and banged their knee. The worker was provided first aid on December 12 and returned to full duties for the remainder of their shift. The worker later provided a sick note stating they were unable to return to work on their next scheduled shift. Cameco learned that the absence may be due to an off-site diagnosis of a psychological injury related to the workplace event involving the worker on December 11, 2023. The injury is being classified as a lost-time injury. The event involving the run of muck has been deemed a dangerous occurrence.
Corrective ActionBoth the nursing team and the disability management team have been engaged in this event to ensure proper care is available for the worker.
Environmental Effectnot applicableN/A
DateJuly 10, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsDuring the annual field verification of all radioactive sources, site radiation staff were unable to locate one americium 241 check source that is included in the source inventory list.  The source activity is below the exemption quantity. After reporting to the supervisor, a secondary search of the sealed source storage area was completed.
Corrective ActionThe site is investigating whether the source was previously disposed or transferred and not removed from the inventory list.
Environmental Effectno measurable impact to the environment1
DateJune 22, 2023
IncidentReportable Spill, Discharge, Discovery or Release
DetailsApproximately 150 litres of contaminated liquid from the mine water treatment process were released to the ground adjacent to the Mine Water Treatment Plant. The amount released was confirmed to be well below the discharge quantity of 1000 L and was due to a leak in the filter system used to separate the solids from the mine water.
Corrective ActionThe affected area was cleaned and the contaminated material was placed on a mineralized ore storage pad. A radiation scan of the area confirmed the release was fully cleaned. The maintenance department repaired the filter system and curtains were installed around the perimeter of the filter system.
Environmental Effectno measurable impact to the environment1
DateMay 10, 2021
IncidentReportable release
DetailsAn increase in outdoor temperatures caused snow meltwater to accumulate within utilidor sump #7 and approximately 2,000 liters of meltwater overflowed the sump onto the ground. This event is classified as a reportable release.
Corrective ActionAn alternative pumping system has been set up. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateMarch 12, 2021
IncidentFire alarm system activation
DetailsThe Emergency Response Team (ERT) responded to a fire alarm activation on the third floor east wing of the permanent camp.The Emergency Response Team (ERT) responded to a fire alarm activation on the third floor east wing of the permanent camp.
Corrective ActionThe ERT team swept the area and determined the fire alarm activation was due to steam. Area was cleared to allow tradespeople to mitigate issue with assistance of ERT team members.  Federal regulators were informed.
Environmental Effectnot applicableN/A
DateFebruary 8, 2021
IncidentFire alarm system activation
DetailsAt approximately 12:30 p.m. the fire alarm system in the main camp was activated as a result of light smoke detected in the E-wing. In accordance with emergency procedures, camp residents reported to the designated muster point and the emergency response team (ERT) responded and verified that there was no fire. The cause of the observed smoke was determined to be a damaged belt on the air handling unit.
Corrective ActionThe camp wing was ventilated and the belt was replaced. Once the area was verified as safe, the alarm system was reset. The CNSC has been notified and follow-up reporting will take place.
Environmental Effectnot applicableN/A
DateSeptember 18, 2020
IncidentFire alarm system activation
DetailsAt approximately 12:30 p.m. a fire alarm was activated underground near the material delivery chute on the 640 level. The emergency response team (ERT) responded in accordance with emergency procedures and verified that there was no fire.
Corrective ActionAn investigation into the cause of the false alarm is underway. The CNSC has been notified.
Environmental Effectnot applicableN/A
DateJuly 29, 2020
IncidentFire system activation
DetailsThe emergency response team (ERT), responded to fire system activation in the north-ex refuge station (530 level) underground. The ERT responded in accordance with emergency procedures and verified that there was no fire or smoke.
Corrective ActionInvestigation indicated that high humidity levels caused a smoke detector to go into alarm. The CNSC was notified.
Environmental Effectnot applicableN/A

Cameco Environmental Effect Rating

  • Level 1 - no measurable impact to the environment 
  • Level 2 - negligible impact
  • Level 3 - short-term, seasonal impact 
  • Level 4 - mortality of some species, but not affecting ecosystem function 
  • Level 5 - impairment of ecosystem function 
  • N/A - not applicable

Key Lake

DateJune 5, 2024
IncidentReportable Event
DetailsA worker was lifting a tooling apparatus and felt pain in their elbow. The injury was initially classified as a restricted work event and the worker continued to perform modified duties. A secondary assessment by an offsite medical professional determined further treatment was required, and the event was reclassified as a lost-time injury on June 5, 2024. 
Corrective ActionN/A
Environmental EffectN/AA/N

 

Past reporting

Key Lake

DateJune 5, 2024
IncidentReportable Event
DetailsA worker was lifting a tooling apparatus and felt pain in their elbow. The injury was initially classified as a restricted work event and the worker continued to perform modified duties. A secondary assessment by an offsite medical professional determined further treatment was required, and the event was reclassified as a lost-time injury on June 5, 2024. 
Corrective ActionN/A
Environmental EffectN/AA/N
DateMay 27, 2024
IncidentEvent Requiring Reporting to the Duty Officer
DetailsA shutter cover was found to have been improperly placed over a nuclear density gauge, allowing process material from a leaking pipe to drip directly onto it and causing corrosion damage. The gauge was not leaking.
Corrective ActionThe cover was properly placed over the gauge. The gauge was removed from service and will be disposed.
Environmental Effectno measurable impact to the environment1
DateMay 18, 2024
IncidentReportable Discharge
DetailsDuring an inspection of the turbine driver unit in the acid plant building, a one-inch steam drain hose from the high-pressure side of the turbine ruptured while the operator was nearby, spraying high-pressure steam in the opposite direction of the operator. The operator was using all appropriate PPE. No injuries were reported.
Corrective ActionThe operator shut down and isolated the turbine driver unit and removed the ruptured drain hose. The area is being inspected to determine the extent of condition. The event has been entered into the Cameco Incident Reporting System (CIRS) for further investigation.
Environmental Effectno measurable impact to the environment1
DateMay 3, 2024
IncidentReportable Discharge
DetailsAt 3:00 a.m., approximately 150 m3 of treated industrial water was released to the ground from a manhole near the acid plant. The volume exceeds the reporting threshold of 100,000 L.
Corrective Action

Environment personnel completed a visual site assessment, identified a cracked valve and collected a water sample. The leaking valve inside the manhole was isolated by closing another valve upstream. Repairs are underway.

The incident was reported to the CNSC and Saskatchewan Ministry of Environment.

Environmental Effectno measurable impact to the environment1
DateApril 27, 2024
IncidentReportable Discharge; Dangerous Occurrence
Details

During routine maintenance, while draining water containing residual ammonia from the ammonia vaporizer, the 1” drain hose ruptured. This resulted in the release of ammonia vapor inside the vaporizer building which vents to the atmosphere.

At the time of the event, an operator was working next to the hose as it ruptured. The operator was utilizing all appropriate PPE and there was no injury as a result of this event.

Corrective Action

Operator utilized the safety shower to remove any potential ammonia substances from the release and evacuated the vaporizer building. The monitoring system triggered automated shutdown of the ammonia systems. The Safety department tested ammonia levels and determined there was no immediate risk to the health and safety of workers. The area was roped off until residual ammonia levels decreased.

The incident was reported to the CNSC and Saskatchewan Ministry of Environment.

Environmental Effectnot applicableN/A
DateMarch 12, 2024
IncidentReportable Spill, Discharge, Discovery or Release
DetailsFollowing routine review, the Industrial Water Reservoir level was found to be decreasing below the normal operating level. Upon investigation, the industrial water pipeline located underground was determined to be leaking and the industrial water (treated effluent) was found at the surface approximately 85 meters south of the Ore Receiving building. The pipeline, which supplies the industrial and fire protection water, needed to be shutdown, resulting in production being temporarily halted. The amount of industrial treated water released is above the reporting threshold of 100,000 L.
Corrective ActionThe incident was reported to the CNSC and Saskatchewan Ministry of Environment. Excavation of the area identified a failed coupling, which has been repaired. Hot work on site had been prohibited and fire watch rounds were implemented until the fire protection systems were fully restored. Production resumed on the morning of March 14, 2024.
Environmental Effectno measurable impact to the environment1
DateFebruary 27, 2024
IncidentLost-Time Incident
DetailsWhile drilling a hole, a worker caught their glove in the spade bit, resulting in a cut to their finger. The worker was assessed at the site Health Center and the injury was initially classified as a restricted work event. A secondary assessment by an offsite medical professional determined the worker was unable to return to work. This was reclassified as a lost-time injury on March 14, 2024.
Corrective ActionA lack of hazard recognition and improper tool use was determined to be the cause.
Environmental Effectnot applicableN/A
DateJanuary 20, 2024
IncidentRadiation Action Level Exceedance
DetailsWhile building scaffold in the horizontal calciner, two workers were exposed to calcined yellowcake material resulting in dose estimates above the weekly action level of 1mSv. The workers had worn their coveralls into a lunchroom trailer. Investigation determined the trailer had detectable levels of contamination, requiring it to be thoroughly washed and re-tested to verify cleanliness. 
Corrective ActionFollowing a review, both workers were placed on enhanced monitoring and an investigation commenced. The work procedure was revised for this area which includes a decontamination process. The event has been reported to the CNSC.
Environmental Effectnot applicableN/A
DateNovember 27, 2023
IncidentReportable Spill, Discharge, Discovery or Release
DetailsWhen testing the industrial water booster pump after maintenance, approximately 3,750 L of industrial water was released from a hose near Pond 5. The operator accidently opened a valve to a hose connected to the line. The operator closed the valve and reported the event to the Environment Department.
Corrective ActionA sample was collected from the line and the area was inspected for erosion. The event has been reported to the CNSC. 
Environmental Effectno measurable impact to the environment1
DateNovember 13, 2023
IncidentLost-time injury
DetailsA worker attempted to open the hood from the side of the slurry power unit and felt a muscle strain in their back. The worker did not report the injury immediately as required and finished their shift. The worker then reported the injury to their supervisor and was assessed at the Health Center. The injury was initially classified as a restricted work event but was reclassified as a lost-time injury on December 7. 
Corrective ActionThe worker did not follow instruction by lifting the slurry power unit hood from the wrong location, not requesting help to lift hood, and not reporting injury immediately. Further investigation to be completed.
Environmental Effectnot applicableN/A
DateNovember 11, 2023
IncidentLost-time injury
DetailsWhile a worker was loosening a steel pipe with a pipe wrench in the Acid Plant, the worker felt a strain in the inner elbow. The worker immediately stopped the task and reported to the Health Center for assessment. The injury was initially classified as a restricted work event but was reclassified as a lost-time injury on December 7. 
Corrective ActionProper ergonomics were utilized, and the worker was not exerting a great level of force to loosen the pipe. No specific point of error was identified. Further investigation to be completed.
Environmental Effectnot applicableN/A
DateNovember 9, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsA worker was exposed to uranium slurry while performing clean-up tasks in the mill. No radiation work permit was obtained and no post-work samples were collected. The worker subsequently completed tasks in another area of the mill that required a radiation work permit and pre- and post-work testing. Both tests showed elevated results with an initial dose estimate above the weekly action level (greater than 1 mSv). Further analysis is underway. 
Corrective ActionCameco placed the worker on enhanced testing with samples being sent for analysis. The worker was assigned to work in a low radiation area until further investigation is completed. Cameco reported the incident to the CNSC.
Environmental Effectnot applicableN/A
DateOctober 8, 2023
IncidentReportable Spill, Discharge, Discovery or Release
DetailsOn October 6, Key Lake workers observed an increase in demand of cooling tower water at a rate of 12.6 m³/hr.  However, no signs of a loss in water were detected until October 8, when water was observed flowing from a crack in the pavement within the packaging coverall. As a result, an estimated 605 m3 of treated industrial water was released.
Corrective ActionAll departments were notified. Site visits were completed, and a course of action determined. Mill Operations shut down to isolate the cooling water line, which is an underground utility. 
Environmental Effectno measurable impact to the environment1
DateSeptember 12, 2023
IncidentRadiation Action Level Exceedance
DetailsA worker performing maintenance in the mill area received a preliminary dose estimate indicative of a weekly action level exceedance.
Corrective ActionConfirmatory enhanced urine collection samples were analyzed at both Key Lake and Port Hope Conversation Facility (PHCF) labs and additional monitoring of the worker occurred at PHCF. Action level exceedance has been reported to the CNSC and an investigation is underway.
Environmental Effectnot applicableN/A
DateSeptember 6, 2023
IncidentRadiation Action Level Exceedance
DetailsA worker performing maintenance on the primary thickener in the counter current decantation (CCD) mill area received a preliminary dose estimate indicative of a quarterly action level exceedance (estimate of greater than 5 mSv). 
Corrective ActionConfirmatory enhanced urine collection samples were analyzed at both Key Lake and McArthur River labs. Action level exceedance has been reported to the CNSC and an investigation is underway.
Environmental Effectnot applicableN/A
DateSeptember 3, 2023
IncidentReportable Spill, Discharge, Discovery or Release
DetailsAn operator was filling the water wagon at the industrial water fill station near the Mine shop. The operator removed the wheel chocks and started the engine to the water wagon prior to disconnecting the fill hose. The water wagon rolled back slightly, which resulted in damage to the industrial water line located within the feed utilidor. Approximately 1,200 m3 of industrial water was released inside the utilidor (secondary containment). An additional 12 m3 was released outside to the ground near the crusher sump.
Corrective ActionThe valve for the fill station was closed and the industrial water line was isolated. Environment personnel collected samples. The water wagon was locked out for mechanical inspection. The proper fill procedures and use of wheel chocks were reviewed with site services personnel.
Environmental Effectno measurable impact to the environment1
DateAugust 16, 2023
IncidentReportable Spill, Discharge, Discovery or Release
DetailsAfter the leak detection alarm was activated, a leaking pipeline within the feed utilidor was discovered. The material was initially released to secondary containment within the feed utilidor. However, approximately 200 kg of uranium ore slurry was released to the ground through a small opening located between the utilidor lids. It was determined the leak was caused by the failure of a victaulic clamp on the pipeline.
Corrective ActionA gamma survey was completed. A vacuum truck cleaned up the material released to the ground and transported it to the ore pads.
Environmental Effectno measurable impact to the environment1
DateJuly 12, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsA fire started in the sulphur pit, which is a concrete structure built into the ground within the Key Lake Acid Plant. The Emergency Response Team responded and added 150 lb of dry chemical on the intake side of the pit to smother the fire and drop the temperature within the pit. Water was also added to further drop the temperature. No one was injured in the incident.
Corrective ActionThe cause of the fire is under investigation and the area is being monitored.
Environmental Effectno measurable impact to the environment1
DateJune 27, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsWhile laboratory staff were refilling squirt bottles, nitric acid (1%) was inadvertently mixed with chlorine bleach (10%). This mixture creates chlorine gas. Lab staff immediately alerted their supervisor and evacuated the area. The Emergency Response Team responded to the chemistry lab, performed gas testing and confirmed the area was safe.
Corrective ActionThe mixture was properly disposed. While the bottles had the proper WHMIS labels, laboratory staff have implemented a visual check by adding color to the exterior of each bottle to further differentiate the chemicals.
Environmental Effectnot applicableN/A
DateJune 6, 2023
IncidentDangerous Occurrence
DetailsWorkers were tasked with changing a motor on a pump in the secondary containment of the #1 and 2 Leach Pachuca's. The crane was test ran to ensure that it travelled North, South and up and down. While conducting the initial lift of the motor, the workers noticed that one side of the rollers on the Storage Pachua Chain Hoist trolley had shifted and became partially dislodged from the I-Beam. The workers immediately lowered the motor back down onto a secure platform and secured the crane with a chain hoist. There were no injuries as a result of this event. The motor being lifted was 475 pounds and the crane is rated for 1 tonne. The lift area was roped off prior to utilizing the crane, so there were no workers present in the area below.
Corrective ActionThe incident scene was secured; crane was tagged out and then danger taped off to aid in the investigation of the incident and remove any risk to workers in that area. The OHC committee was convened on June 6, 2023, to investigate the event and ruled the incident a Dangerous Occurrence. Further investigation is currently under way.
Environmental Effectnot applicableN/A
DateMay 31, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsIn the Mill Facility, an employee fell down the staircase in the yellowcake area, resulting in injuries to their shoulder, knee, elbow, and hand.  The emergency response team provided initial assessment and treatment. The employee left on a regularly scheduled flight for an offsite assessment accompanied by an ERT member. It was determined the individual did not sustain any fractures.
Corrective ActionThere were no issues noted with the staircase handrail and no tripping hazards were observed. Further investigation will be completed.
Environmental Effectnot applicableN/A
DateApril 25, 2023
IncidentPotential Radiation Action Level Exceedance
DetailsA pinhole leak developed on the line between Continuous Stir Tank Reactors 4 and 6, inside the leaching circuit building. This resulted in leaching process material (slurry) intermittently spraying and potentially misting along the wall and walkway. Five individuals were working in the area and were contacted by the slurry mist. The preliminary dose estimates for two individuals indicated a potential weekly action level exceedance (estimate of greater than 1 mSv). Further analysis is required to confirm the dose calculations.
Corrective ActionThe area was barricaded and cleaned up. The leak on the pipe was isolated and repairs were completed. Five individuals in the area completed Uranium in Urine sampling to evaluate the possibility for intake. Samples from two workers indicated potential for measurable dose. Enhanced U in U samples for these workers were shipped to Port Hope for analysis and confirmation of the results was received on May 10th.
Environmental Effectnot applicableN/A
DateApril 15, 2023
IncidentEvent Requiring Reporting to the Duty Officer
DetailsThe emergency response team responded to and extinguished a small amount of saw dust that was observed smoldering in a waste bin outside the maintenance shop.  
Corrective ActionThe event was investigated and the cause is believed to be due to an overheated saw blade.
Environmental Effectno measurable impact to the environment1
DateApril 15, 2023
IncidentEmergency Transport to External Medical Facilities / Dangerous Occurrence
DetailsWhile working in the Crushing and Grinding building, a worker was struck by a phone booth unit that dislodged from its mounting brackets. The emergency response team was activated to provide medical care and transport to the site health centre. The worker was transported offsite in stable condition via air ambulance for further assessment.
Corrective ActionThe incident scene was secured and all other similar phone booth structures at the operation have been taped off until further assessment can be completed. The OHC committee was convened to investigate the event.
Environmental Effectnot applicableN/A
DateJanuary 10, 2023
IncidentRadiation Action Level
DetailsWhile performing maintenance on a leaching vessel, two workers had an unplanned radiation exposure that led to exceedances of the quarterly action level of 5 mSv.  The total annual dose for both workers remains well below regulatory limits.
Corrective ActionThe workers were removed from the their tasks to complete the follow-up investigation and dose assessment process. The remaining maintenance work on the leaching vessel was completed in accordance with the applicable procedure without incident.
Environmental Effectno measurable impact to the environment1
DateNovember 25, 2022
IncidentReportable Discharge
DetailsAround 3 a.m., technicians were installing a new helium cylinder in the Chemical Lab gas storage room. When removing the plastic safety cover from the new cylinder outlet valve, the helium began venting. The lab gas storage room was immediately evacuated and sealed off to allow the cylinder to safely vent. The discharge of the helium was approximately 30 minutes in duration, which exceeds the reportable discharge duration of less than 10 minutes.
Corrective ActionNo entry to the gas storage room was allowed until the air monitoring system indicated it was safe. The cylinder was properly secured at the time of the release. It will be sent back to the manufacturer to investigate if the valve was defective.
Environmental Effectnegligible impact2
DateNovember 24, 2022
IncidentRegulatory Emission Limit Exceedance
DetailsThe Total Suspended Solids (TSS) regulatory emission limit of 30 mg/L for a grab sample collected from treated water was exceeded for a partial pond released at station 1.4, Bulk Neutralization Effluent discharge. Prior to release, analysis of the pond fill sample returned a TSS value that was acceptable for release. During release, the in-line turbidity monitoring interlock system was activated, halting the discharge. Additional samples were taken and returned results that were acceptable for release. Pond release resumed, however, the turbidity interlock system halted the release a second time, and the remainder of the pond was recycled back to Bulk Neutralization for treatment. The pond release sample was analyzed and returned a value of 37 mg/L, exceeding the regulatory emission limit for a grab sample. Approximately 32% (1307 m3) of the pond was released to the environment and 68% (2788 m3) was recycled.
Corrective ActionAn additional sample was sent to the SRC Analytical Laboratory for further verification. A sample collected on November 25 from the nearest downstream sample location at Station 4.0 Wolf Lake, indicated normal TSS levels. Further investigation is currently underway.
Environmental Effectnegligible impact2
DateOctober 28, 2022
IncidentEnvironmental Action Level Exceedance
DetailsIn accordance with site procedures, a pond of treated effluent was released based on the results of the pond fill composite sample. Results for the pond release composite sample indicated the measured value for uranium (81 µg/L) exceeded the action level of 80 µg/l. Measured results for all parameters, including uranium, were well below the applicable regulatory limits. There was no health or safety risk posed to the public, workers or the environment.
Corrective ActionCameco notified the Canadian Nuclear Safety Commission, and an investigation has been initiated.
Environmental Effectnegligible impact2
DateOctober 22, 2022
IncidentReportable Release
DetailsA line at Key Lake’s processing facility released water to the ground. It is believed the line was frozen, causing the release. 6 cubic metres of industrial water was released.
Corrective ActionOperations lowered the water level in a tank to prevent further overflow to the line. Environment was contacted to collect samples and Site Services used a vacuum truck to clean up the area. The material was disposed of on site.
Environmental Effectnegligible impact2
DateSeptember 20, 2022
IncidentReportable Release
DetailsAn estimated 2,000 litres of industrial wastewater from the mine shop pump bay sump were released on the ground when the pump testing pit overfilled with potable water. It was determined that when a hose was placed on the hose rack next to the fill valves, the potable water fill valve was bumped into the “on” position, resulting in the sump to fill and overflow.
Corrective ActionThe supervisor was notified, and the fill valve was shutoff. The event was reported to the environment and site services departments for investigation and cleanup. Federal and provincial regulators were notified.
Environmental Effectnegligible impact2
DateJuly 13, 2022
IncidentEvent Requiring Reporting to the CNSC Duty Officer
DetailsThe incident command centre has been activated in response to a fire southwest of Key Lake. The Key Lake site is not currently under immediate threat. The Saskatchewan Public Safety Agency (SPSA) crews continue to monitor closely.
Corrective ActionThe SPSA continues to monitor and provide updates to site. The site re-established a fuel break at the VOR station located approximately 10 km southwest of Key Lake, at the direction of the SPSA.
Environmental Effectnot applicableN/A
DateJuly 5, 2022
IncidentRadiation Action Level Exceedance
DetailsElevated monitoring sample measured for worker post CCD thickener maintenance. Preliminary dose estimate indicated a quarterly action level may have been exceeded. Further analysis was required to confirm dose calculations.
Corrective ActionAll work was stopped in the area until initial investigation was completed. Workers convened for a JHA to discuss procedure for any work in the CCD thickener going forward. Samples were shipped to an external lab for confirmatory analysis.
Environmental Effectnot applicableN/A
DateMarch 29, 2022
IncidentReportable release
DetailsAt about 10:15 a.m., during daily inspection, ground water from Well V of the Gaertner dewatering system was observed in a small area outside the well shelter. Release volume is estimated at more than 1000 litres.
Corrective Action

The reverse osmosis plant feed was re-routed to an alternate well, isolating Well V from the dewatering system. Water samples were collected and site services conducted cleanup.  Further investigation into the incident will be conducted after ground thaws.

Provincial and federal regulators were notified.

Environmental Effectno measurable impact to the environment1
DateFebruary 16, 2022
IncidentReportable release
DetailsAt about 4:00 a.m., a propane leak was detected near the steam plant.
Corrective ActionA faulty propane line was isolated and the area secured. Cause of the line failure is under investigation. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateDecember 27, 2021
IncidentReportable release
DetailsAt about 2:50 a.m., an alarm indicated a propane leak on propane pump #2, near the steam plant.
Corrective ActionThe pump was isolated and the cause of the leak was determined to be a broken pipe fitting to the pressure gauge on the pump. The cause of the breakage is under investigation. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateSeptember 20 and September 27, 2021
IncidentUnusual incidents
DetailsThe weekly effluent sample for the Reverse Osmosis (RO) effluent at Station 1.2 Discharge to Horsefly Lake was not collected on the above dates.  Station 1.2.1 Horsefly Lake Outflow was mistakenly collected in place of the Station 1.2 Discharge to Horsefly Lake.  
Corrective ActionThe RO daily product sample results were reviewed, and all parameters analyzed on both days were confirmed to be below the Metal and Diamond Mining Effluent Regulation (MDMER) limits.  
Environmental Effectno measurable impact to the environment1
DateSeptember 13, 2021 
IncidentReportable release
DetailsA propane leak was detected in a line outside of the CCD, near the Leaching facility. Corrosion to the piping was observed.
Corrective ActionValve was closed and locked to stop the flow and repairs will be initiated. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateSeptember 7, 2021 
IncidentEvent Requiring Reporting to the Duty Officer
DetailsOn September 7th, the Emergency Response Team was activated at 10:15am and responded to a non-work-related medical emergency involving a person working at the mill terrace reservoirs. The team was stood down at 10:55am.
Corrective ActionThe Emergency Response Team responded and provided initial assessment and transported the worker in stable condition to the health centre for additional assessment and care.  
Environmental Effectnot applicableN/A
DateJune 22, 2021 
IncidentReportable release
DetailsExamination of 2020 and 2021 groundwater sampling results from new monitoring wells indicated elevated levels of parameters such as ammonia and sulfate below the mill terrace area.
Corrective Action

An assessment indicates the source is likely a release of water contaminated with barren strip solution. The release is believed to have occurred prior to the operation being placed into care and maintenance in 2018, as tests have indicated there is not an active discharge occurring.

Further investigation is underway. Additional drilling and sampling will be completed to further assess groundwater conditions in this area. Inspections and repairs will be completed prior to resumption of production.

Provincial and federal regulators were notified.

Environmental Effectnegligible impact2
DateApril 18, 2021 
IncidentDangerous occurrence
DetailsWhile decommissioning electrical cables in the packaging area, a 120V energized wire was inadvertently cut. This caused the breaker to trip and no injuries occurred.
Corrective ActionThe electrical wire was repaired and an investigation is underway.  Provincial and federal regulators were notified.
Environmental Effectnot applicableN/A
DateFebruary 12, 2021
IncidentReportable release
DetailsAt around 8:15 a.m., a leak detection alarm in Valve Shelter #1 was activated after a damaged 3-inch pipe released approximately 3m3 of water to the floor of the shelter and outside the doorway. Upon investigation, it was determined that freezing temperatures had caused the pipe to split.
Corrective ActionA lateral valve in the shelter was closed, which stopped the release. The material was cleaned up utilizing a vacuum truck. The damaged pipe is being repaired. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateOctober 27, 2020
IncidentReportable release
DetailsAt approximately 6:15 a.m., workers noted that a water supply line valve in the wash bay had been left open overnight resulting in the release of approximately 12,000 litres of water onto the frozen ground outside the building.
Corrective ActionWorkers shut off the water supply valve. Water samples were collected for analysis and the slush/ice build-up on the frozen ground was removed for transfer to the Phase IV Ore Pad.  Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateMarch 17, 2020
IncidentReportable release
DetailsAt approximately 2:30 p.m. in the reverse osmosis (RO) facility, the automated shutdown of water pumps failed resulting in the release of approximately 3,000 litres of dewatering water to the ground.
Corrective ActionAll wells providing water to the RO plant were shut down. Released water, which froze in place on the ground, was removed and placed on the Gaertner special waste pad. Preliminary investigation indicates a system communication power loss, from a UPS failure during maintenance testing, resulted in loss of signal between the high water level alarm and automated pump shutdown system. Provincial and federal regulators were notified.
Environmental Effectno measurable impact to the environment1
DateMarch 8, 2020
IncidentEmergency response team (ERT) activation
DetailsAt 12:24 p.m., the emergency response team (ERT) responded to a burst fire system water line in the stairwell of the mine shop.
Corrective ActionWater was isolated and the line was repaired. ERT investigation revealed the line had frozen and burst due to cold weather and heating failure. Federal regulators were notified.
Environmental Effectnot applicableN/A

Cameco Environmental Effect Rating

  • Level 1 - no measurable impact to the environment 
  • Level 2 - negligible impact
  • Level 3 - short-term, seasonal impact 
  • Level 4 - mortality of some species, but not affecting ecosystem function 
  • Level 5 - impairment of ecosystem function 
  • N/A - not applicable

Decommissioning

Detailed plans and financial guarantees are in place to provide for decommissioning of the McArthur River and Key Lake sites when operations end. Decommissioning will include removal of all buildings and equipment and landscaping and re-vegetation of disturbed areas. All underground workings and other mine and mill facilities will be sealed off and secured. A monitoring program will be in place to ensure the sites remain in a secure and stable state for the long-term.

For more information, see:

Preliminary Decommissioning Plan - Summary - McArthur River Operation

Preliminary Decomissioning Plan - Summary - Key Lake Operation

Environmental Risk Assessment

All new, or substantially changed, mining developments may be subject to environmental risk assessments (ERAs) to identify potential effects on the environment. ERAs follow guidance provided by CSA and various agencies, such as Health Canada (HC), Environment and Climate Change Canada (ECCC), Canadian Council of Ministers of the Environment (CCME) and the Canadian Nuclear Safety Commission (CNSC).

In 2020, Cameco completed a detailed quantitative environmental risk assessments (ERA) for its McArthur River and Key Lake Operations to align with the standardized requirements found in CSA N288.6-12 Environmental risk assessment at Class I nuclear facilities and uranium mines and mills (CSA 2012).

Public Summary - Environmental Risk Assessment - McArthur River Operation (PDF 6.7 MB)

Public Summary - Environmental Risk Assessment - Key Lake Operation (PDF 3.8 MB)

Tailings Management

Tailings, or what remains of the ore after the uranium has been removed at the Key Lake mill, is placed in the Deilmann tailings management facility. Commissioned in 1996, the facility is built into the mined out Deilmann pit and is designed to safely contain the tailings during continuing operations and after decommissioning. Tailings are placed in the pit under a water cover. During operations, groundwater is collected from a series of wells around the facility and is treated prior to release to the environment. When operations cease, the tailings will become a solid dense mass and groundwater will flow around the tailings, rather than through them, to minimize environmental impact.

Prior to 1996, tailings from the Key Lake mill were deposited in a surface tailings management facility approximately 600 metres by 600 metres and 15 metres deep. The facility was constructed five metres above the groundwater table and used a modified bentonite liner to isolate the tailings from the surrounding soil.

Regulatory Oversight

The primary regulator for the McArthur River and Key Lake operations is the Canadian Nuclear Safety Commission (CNSC). These operations are also subject to regulatory oversight from several other federal and provincial agencies including Saskatchewan Ministry of Environment. Federal and provincial regulators conduct regular site inspections and audits to verify that people and the environment are protected. Uranium mining and milling operations in Canada are licensed by the CNSC.

Image
Environment, governance, social image

Sustainability at Cameco

When measuring the sustainability and ethical impact of a company, environmental, social and governance (ESG) are key factors considered by the public and investors. Sustainability and ESG matters have been an important focus at Cameco for many years and we have a strong performance record.

Learn more