Back To Top
Community Information Bulletins/Update #1: Non-Compliance in Sewage Effluent
April 24, 2024

Update #1: Non-Compliance in Sewage Effluent

The following information bulletin is in accordance with Canadian Nuclear Laboratories’ (CNL) ongoing commitment to voluntary public disclosure of events related to the Chalk River Laboratories site.

Chalk River, ON – April 24, 2024 – As described in the Community Bulletin issued on March 26, 2024, results of CNL’s routine sampling conducted in February 2024 on effluent (treated discharge) from the conventional Sanitary Sewage Treatment Facility (SSTF) at Chalk River Laboratories were non-compliant with requirements.

Testing at that time had indicated that the activated sludge (micro-fauna) that are part of the treatment process were disrupted, resulting in the non-compliant test result. Upon discovering the issue, CNL notified all relevant regulatory agencies and initiated an investigation to identify the cause of the disruption.

Since that time, CNL has conducted further testing on the SSTF effluent, and results show that the treated discharge does not meet the necessary requirements. In line with a Direction from Environment and Climate Change Canada, CNL is taking extensive measures to fully understand what is leading to the non-compliance and to return the SSTF to normal operations. These activities include:

  • Increased toxicity testing on SSTF effluent
  • The procurement of third-party support to complete a toxicity evaluation on SSTF effluent and to review all facility operations
  • A detailed review, as well as chemical analysis, on all SSTF influent and effluent
  • The delivery of company-wide training on allowable releases to the SSTF and a communication campaign to support staff education
  • A review of all known discharges to the SSTF to identify abnormal activities and the cessation of a routine release within one of CNL’s research laboratories
  • Facility improvements to restore the necessary treatment process

CNL remains fully committed to the protection of the environment and continues to work diligently to bring the effluent back into compliance with provincial standards. Because of the complex nature of the micro-fauna system, the timing of when the system will be fully repaired is unknown. CNL will provide biweekly progress reports to Environment and Climate Change Canada until the issue is resolved.


Philip Kompass
Director, Corporate Communications
[email protected]