Position on the Performance Standards of the Canada-wide Strategy for the Management of Municipal Wastewater Effluent

Canadian Council of Ministers of the Environment’s Canada-wide Strategy for the Management of Municipal Wastewater Effluent – Application of the Performance Standards

Background

On February 17, 2009, the Canadian Council of Ministers of the Environment (CCME) adopted the Canada-wide Strategy for the Management of Municipal Wastewater Effluent (the Strategy). Although Québec has not yet officially sanctioned the Strategy, it is important to be certain that criteria selected for new domestic wastewater treatment projects incorporate at a minimum, the performance standards established by the Strategy so as to not authorize projects that may become compromised in the near future.

Position of the Ministère

Domestic wastewater treatment projects¹ need to meet at a minimum, the following performance standards² :

• 25 mg/l for carbonaceous (CBOD₅) five-day biochemical oxygen demand
• 25 mg/l for total suspended solids (TSS)

These are minimum standards. When justified by the establishment of more restrictive environmental discharge objectives (EDOs), taking into account the assimilative capacity of the receiving body of water, stricter discharge requirements may be set by the Ministère, taking into consideration available and economically feasible technologies.

These standards apply to effluent discharge at the wastewater treatment plant. They are not applicable to sewer overflows and are to be applied on the basis of average values measured over a period as defined in the Strategy. TSS may exceed the standard if exeedance is caused by algae.

All new domestic wastewater treatment projects and all modernization or capacity increase must be designed so as to meet these standards, at a minimum. This position does not apply however to projects involving the addition of equipment to allow for supplementary removal of a parameter, for example, adding disinfection or phosphorus removal.

To summarize, this position targets:

• Projects with treatment plant capacity increase (in flow or mass loading)
• Projects that involve modernization of the main process (reconstruction, fundamental changes to the process, discharge requirement changes in BOD or TSS)

This position does not target:

• Projects that only involve addition of equipment used for further removal of a parameter without changing the main process, for example, the addition of disinfection or phosphorus removal.
• Projects that only involve the replacement of equipment by other, similar equipment, without affecting treatment performance, such as the replacement of defective or outdated mechanical equipment.

[1] To clarify the current position, domestic wastewater includes wastewater from municipal, community, commercial and institutional sources, strictly domestic wastewater from industrial sources, and wastewater from isolated dwellings not covered by A Regulation respecting waste water disposal systems for isolated dwellings.
[2] The Strategy’s Canada-wide Performance Standards also include a total residual chlorine standard that applies whenever chlorine disinfection is employed. The position of the Ministère on disinfecting wastewater effluents prohibits chlorine disinfection, thus rendering the standard obsolete.