Draft revisions to the Drinking Water Quality Management Standard (DWQMS) being proposed by Ontario’s Ministry of Environment and Climate Change (MOECC) would require Operating Authorities to take a closer look at the long-term consequence of a wide range of environmental, human and technical threats to the municipal residential drinking water systems they manage. The expanded assessment and planning requirements, if adopted, could also significantly increase the paper burden and compliance costs of owners and operators.

While many of the proposed administrative and housekeeping changes are intended to simply clarify existing requirements in the standard, the revisions would also require Operating Authorities to undertake risk assessments to gauge the potential effects of climate change, extreme weather, algal blooms, terrorist threats, technical breakdowns and other hazardous events identified by the Ministry.

The assessment requirements set out in the existing standard would be maintained. Namely, any additional hazards must also be identified, the risks posed by all hazards ranked, and control measures and critical control points identified. The currency of the information and the validity of the assumptions used in the assessments must be verified annually, and the risks re-assessed at least every 36 months.

In addition, the adequacy of the infrastructure necessary to operate and maintain the system would have to be reviewed in light of these risk assessments. Operating Authorities would also be required to: prepare a long-term forecast of major infrastructure maintenance, rehabilitation and renewal activities; consider best management practices in the context of continual improvement; document a process for the identification and management of corrective actions; and document a process for the identification and implementation of preventive actions.

Under the Safe Drinking Water Act, 2002, the Operating Authority of a municipal residential drinking water system must establish and maintain a Quality Management System that meets the minimum requirements specified in the DWQMS. In turn, Operating Authorities must be accredited by a third party accreditation body against the requirements of the standard.