Environment & Safety

In 2016, Cameco's McArthur River mine was awarded the Canadian Institute of Mining, Metallurgy and Petroleum's prestigious John T. Ryan National Safety Trophy for the third consecutive year.

In 2015, McArthur employees and contractors worked 1.86 million hours without a lost-time injury.

Safety

The McArthur River mine and the Key Lake mill are among Canada's safest mining operations. Each operation has a systematic program to identify, evaluate and mitigate risks and engage all workers and managers in development of a strong safety culture. These programs follow the international OHSAS 18001 model and have delivered excellent safety performance.

Full-time equivalent dose

(mSv/yr)

  2020
McArthur River 0.6
Key Lake 1.0

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

Environmental protection at the McArthur River and Key Lake operations is assured through ISO 14001-certified environmental management systems. These programs systematically identify, control and monitor environmental aspects associated with the facilities.

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

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Metal and Diamond Mining Effluent Regulations (mg/L) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.3
McArthur River Level (mg/L) 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001

0.0001

0.0001

0.0001

0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001

Key Lake Monitoring Results

Treated Water Quality — Arsenic

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.3
Key Lake Level (mg/L) 0.0097 0.0015 0.0026 0.0149 0.0278 0.0029 0.0011 0.0009 0.0001

0.0007

0.0298

0.0108

0.0169 0.0175 0.0180 0.0160 0.0139 0.0118 0.0066 0.0066 0.0064 0.0060 0.0089 0.0086

McArthur River Monitoring Results

Treated Water Quality — Copper

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3
McArthur River Level (mg/L) 0.0005 0.0008 0.0007 0.0005 0.0008 0.0005 0.0007 0.0005 0.0002

0.0004

0.0006

0.0007

0.0012 0.0006 0.0005 0.0004 0.0009 0.0010 0.0006 0.0004 0.0004 0.0003 0.0005 0.0002

Key Lake Monitoring Results

Treated Water Quality — Copper

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3
Key Lake Level (mg/L) 0.0012 0.0009 0.0037 0.0024 0.0013 0.0010 0.0008 0.0010 0.0009

0.0014

0.0005

0.0005

0.0003 0.004 0.0034 0.0017 0.0011 0.0010 0.0008 0.0005 0.0004 0.0003 0.0007 0.0046

McArthur River Monitoring Results

Treated Water Quality — Lead

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.1
McArthur River Level (mg/L) 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001

0.0001

0.0001

0.0001

0.0002 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001

Key Lake Monitoring Results

Treated Water Quality — Lead

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.1
Key Lake Level (mg/L) 0.0002 0.0001 0.0001 0.0003 0.0001 0.0001 0.0001 0.0002 0.0001

0.0009

0.0002

0.0001

0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0003 0.0001 0.0001 0.0001 0.0002 0.0009

McArthur River Monitoring Results

Treated Water Quality — Nickel

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
McArthur River Level (mg/L) 0.0010 0.0016 0.0016 0.0016 0.0014 0.0018 0.0019 0.0014 0.0016

0.0014

0.0011

0.0011

0.0013 0.0012 0.0013 0.0014 0.0014 0.0023 0.0024 0.0026 0.0027 0.0023 0.0020 0.0017

Key Lake Monitoring Results

Treated Water Quality — Nickel

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Key Lake Level (mg/L) 0.1594 0.1903 0.1740 0.0860 0.2175 0.1454 0.1685 0.1648 0.2176

0.2025

0.0993

0.0998

0.2383 0.1447 0.1172 0.0708 0.0823 0.2142 0.1228 0.0935 0.0844 0.0710 0.1106 0.0920

McArthur River Monitoring Results

Treated Water Quality — Zinc

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
McArthur River Level (mg/L) 0.0026 0.0042 0.0039 0.0026 0.0025 0.0034 0.0028 0.0031 0.0019

0.0016

0.0013

0.0016

0.0024 0.0020 0.0016 0.0014 0.0018 0.0021 0.0032 0.0027 0.0050 0.0025 0.0026 0.0020

Key Lake Monitoring Results

Treated Water Quality — Zinc

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Key Lake Level (mg/L) 0.0039 0.0057 0.0078 0.0050 0.0091 0.0079 0.0110 0.0091 0.0113

0.0099

0.0034

0.0018

0.0044 0.0020 0.0021 0.0028 0.0032 0.0080 0.0056 0.0043 0.0040 0.0030 0.0003 0.0058

McArthur River Monitoring Results

Treated Water Quality — Suspended Solids

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15
McArthur River Level (mg/L) 0.9 0.9 0.9 0.9 1.0 0.9 1.0 1.0 1.0 1.0 1.0 1.0 2.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Key Lake Monitoring Results

Treated Water Quality — Suspended Solids

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21

Metal and Diamond Mining Effluent Regulations (mg/L)

15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15
Key Lake Level (mg/L) 1 3 1 2 3 2 2 3 4 2 2 2 3 4 2 0.9 2 3 4 1 2 1 1 2

McArthur River Monitoring Results

Treated Water Quality — Radium-226

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Metal and Diamond Mining Effluent Regulations (Bq/L) 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37
McArthur River Level (Bq/L) 0.046 0.048 0.043 0.056 0.075 0.066 0.068 0.055 0.048

0.048

0.045

0.058

0.052 0.045 0.040 0.040 0.038 0.046 0.035 0.023 0.028 0.040 0.030 0.022

Key Lake Monitoring Results

Treated Water Quality — Radium-226

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Metal and Diamond Mining Effluent Regulations (Bq/L) 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37
Key Lake Level (Bq/L) 0.060 0.080 0.035 0.048 0.048 0.098 0.045 0.080 0.074

0.058

0.031

0.016

0.056 0.025 0.011 0.009 0.009 0.005 0.006 0.006 0.010 0.006 0.008 0.005

McArthur River Monitoring Results

Treated Water Quality — pH

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Authorized Maximum pH 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5
McArthur River Level pH 7.5 7.4 7.4 7.5 7.4 7.5 7.5 7.4 7.5 7.5 7.5 7.5 7.6 7.6 7.5 7.4 7.5 7.4 7.4 7.4 7.4 7.4 7.4 7.4
Authorized Minimum pH 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0

Key Lake Monitoring Results

Treated Water Quality — pH

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Authorized Maximum pH 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5
Key Lake Level pH 6.7 6.6 6.7 6.5 6.6 6.6 6.5 6.5 6.6 6.6 6.6 6.7 6.6 6.5 6.7 6.8 6.9 6.8 7.0 7.1 7.2 7.3 7.4 7.5
Authorized Minimum pH 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0

McArthur River Monitoring Results

Treated Water Quality — Selenium

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Saskatchewan Ministry of Environment Limit (mg/L) 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6
McArthur River Level (mg/L) 0.0002 0.0004 0.0003 0.0006 0.0003 0.0002 0.0002 0.0002 0.0002

0.0002

0.0002

0.0004

0.0005 0.0004 0.0004 0.0003 0.0002 0.0003 0.0003 0.0002 0.0002 0.0002 0.0002 0.0003

Key Lake Monitoring Results

Treated Water Quality — Selenium

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Saskatchewan Ministry of Environment Limit (mg/L) 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6
Key Lake Level (mg/L) 0.0092 0.0103 0.0113 0.0093 0.0113 0.0115 0.0108 0.0100 0.0099

0.0094

0.0091

0.0102

0.0124 0.0093 0.0089 0.0110 0.0110 0.0140 0.0105 0.0104 0.0097 0.0093 0.0090 0.0087

McArthur River Monitoring Results

Treated Water Quality — Uranium

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Saskatchewan Ministry of Environment Limit (mg/L) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
McArthur River Level (mg/L) 0.0067 0.0076 0.0069 0.0099 0.0146 0.0100 0.0106 0.0126 0.0085

0.0072

0.0066

0.0069

0.0047 0.0075 0.0071 0.0066 0.0124 0.0110 0.0117 0.0078 0.0064 0.0107 0.0063 0.0032

Key Lake Monitoring Results

Treated Water Quality — Uranium

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Saskatchewan Ministry of Environment Limit (mg/L) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Key Lake Level (mg/L) 0.0414 0.0383 0.0350 0.0330 0.0258 0.0158 0.0278 0.0258 0.0372

0.0248

0.0190

0.0232

0.0236 0.0148 0.0168 0.0172 0.0195 0.0504 0.0286 0.0420 0.0208 0.0164 0.0288 0.0213

McArthur River Monitoring Results

Treated Water Quality — Molybdenum

  Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
McArthur River Level (mg/L) 0.0130 0.0283 0.0200 0.0109 0.0052 0.0031 0.0036 0.0036 0.0031

0.0032

0.0070

0.0188

0.0160 0.0183 0.0168 0.0115 0.0074 0.0053 0.0040 0.0028 0.0025 0.0047 0.0107 0.0150

Key Lake Monitoring Results

Treated Water Quality — Molybdenum

 

Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21
Key Lake Level (mg/L) 0.0558 0.0265 0.0550 0.1146 0.0503 0.0128 0.0033 0.0028 0.0026

0.0028

0.1362

0.0724

0.0510 0.1190 0.1150 0.0840 0.0628 0.0330 0.0212 0.244 0.0145 0.0210 0.0374 0.0253

McArthur River Monitoring Results

Treated Water Quality — Un-ionized Ammonia as Nitrogen

  Jun-21
Metal and Diamond Mining Effluent Regulations (mg/L)  0.5
McArthur River Level (mg/L) 0.01

Key Lake Monitoring Results

Treated Water Quality — Un-ionized Ammonia as Nitrogen

  Jun-21
Metal and Diamond Mining Effluent Regulations (mg/L)  0.5
Key Lake Level (mg/L) 0.01

McArthur River Monitoring Results

Ambient Air Quality – Annual Average Total Suspended Particulate (TSP)    
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.

  2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Q2
Saskatchewan Ministry of Environment Standard - see note (µg/m³) 70 70 70 70 60 60 60 60 60 60
Annual Average (µg/m³) 7.2 4.9 4.2 4.2 2.3 3.2 1.7 1.4 1.1 1.9

Key Lake Monitoring Results

Ambient Air Quality – Annual Average Total Suspended Particulate (TSP)  
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.

  2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Q2
Saskatchewan Ministry of Environment Standard - see note (µg/m³) 70 70 70 70 60 60 60 60 60 60
Annual Average (µg/m³) 11.5 10.4 10.3 10.0 10.8 12.2 8.8 6.7 5.9 6.4

 

Key Lake Monitoring Results

Ambient Air Quality – Annual Average Ambient Sulfur Dioxide (SO₂) 
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 is shut down, therefore no emissions are reported.

  2012 2013 2014 2015 2016 2017 2018 2019 2020
Saskatchewan Ministry of Environment Standard (ppb) 10 10 10 10 8 8 8 8 8
Annual Average (ppb) 7.7 6.7 7.3 9.1 0.5 0.4 0 0 0

Key Lake and McArthur River entered into a safe state of Care and Maintenance in January 2018.

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:

McArthur River

Date May 10, 2021
Incident

Reportable release

Details

An 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 Action

An alternative pumping system has been set up. Provincial and federal regulators were notified.

Environmental Effect 1

Past reporting

McArthur River

Date May 10, 2021
Incident

Reportable release

Details

An 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 Action

An alternative pumping system has been set up. Provincial and federal regulators were notified.

Environmental Effect 1

 

Date March 12, 2021
Incident

Fire alarm system activation

Details

The 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 Action

The 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 Effect N/A

 

Date February 8, 2021
Incident

Fire alarm system activation

Details

At 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 Action

The 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 Effect N/A

 

Date September 18, 2020
Incident

Fire alarm system activation

Details

At 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 Action

An investigation into the cause of the false alarm is underway. The CNSC has been notified.

Environmental Effect N/A

 

Date July 29, 2020
Incident

Fire system activation

Details

The 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 Action

Investigation indicated that high humidity levels caused a smoke detector to go into alarm. The CNSC was notified.

Environmental Effect N/A

 

Date December 13, 2019
Incident

Fire system activation

Details

At 5:40 pm the McArthur River emergency response team (ERT), responded to fire system activation in B Wing of the permanent camp. The ERT responded in accordance with emergency procedures, cleared the area and verified that there was no fire or smoke.

Corrective Action

The ERT found that activation of the fire system was due to a broken sprinkler line in upper B Wing. The team secured the area and assisted in repairing and rearming the system. The CNSC was notified.

Environmental Effect N/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

Date September 20 and September 27, 2021
Incident

Unusual incidents

Details

The 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 Action

The 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 Effect 1

Past reporting

Key Lake

Date September 20 and September 27, 2021
Incident

Unusual incidents

Details

The 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 Action

The 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 Effect 1

 

Date September 13, 2021 
Incident

Reportable release

Details

A propane leak was detected in a line outside of the CCD, near the Leaching facility. Corrosion to the piping was observed.

Corrective Action

Valve was closed and locked to stop the flow and repairs will be initiated. Provincial and federal regulators were notified.

Environmental Effect 1

 

Date September 7, 2021 
Incident

Event Requiring Reporting to the Duty Officer

Details

On 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 Action

The 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 Effect N/A

 

Date June 22, 2021 
Incident

Reportable release

Details

Examination 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 Effect 2

 

Date April 18, 2021 
Incident

Dangerous occurrence

Details

While 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 Action

The electrical wire was repaired and an investigation is underway.  Provincial and federal regulators were notified.

Environmental Effect N/A

 

Date February 12, 2021
Incident

Reportable release

Details

At 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 Action

A 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 Effect 1

 

Date October 27, 2020
Incident

Reportable release

Details

At 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 Action

Workers 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 Effect 1

 

Date March 17, 2020
Incident

Reportable release

Details

At 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 Action

All 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 Effect 1

 

Date March 8, 2020
Incident

Emergency response team (ERT) activation

Details

At 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 Action

Water 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 Effect N/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 or 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 assessment (ERA) for its Key Lake Operation 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 - 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.

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