Wastewater Systems Effluent Regulations

Jan. 2 2015

In response to a need for better management of Canada’s wastewater systems, the Canadian Council of Ministers of Environment (CCME) undertook to harmonize the management of wastewater being discharged from the more than 3,500 wastewater facilities in Canada.

The Canada-wide Strategy for the Management of Municipal Wastewater Effluent was endorsed by CCME on February 17, 2009.

Wastewater Systems Effluent Regulations

The resulting Wastewater Systems Effluent Regulations (the Regulations), in force on June 1, 2009 and last amended on January 1, 2015, have been established under the Fisheries Act. This bulletin offers a brief summary of the Regulations, on which details can be found in its corresponding subsections.

Application (Subsections 2, 3, 4, 6)

The Regulations apply to any wastewater system that, when it deposits effluent via its final discharge point, deposits a deleterious substance into water frequented by fish or in any place under any conditions where the deleterious substance or any other resulting deleterious substance may enter water frequented by fish, and that:

  • Is designed to collect an average daily volume of 100 m3 (100,000 litres) or more; or
  • During any calendar year, collects an average daily volume of 100 m3 or more of influent.

Exceptions are outlined in Section 3 of the Regulations. The Regulations do not apply to wastewater systems in the far north (the Northwest Territories, Nunavut, and north of the 54th parallel in Quebec or Newfoundland and Labrador). More research is being done to determine an approach for those areas.

Deleterious Substances (Subsection 5)

The deleterious substances listed in Subsection 5 of the Regulations are:

  • Carbonaceous Biochemical Oxygen Demand (CBOD);
  • Suspended Solids;
  • Total Residual Chlorine; and
  • Un-ionized Ammonia.

Authorization to Deposit (Subsection 6 (1))

The owner or operator of a wastewater system may deposit deleterious substances via the system’s final discharge if the effluent is not acutely lethal and, in accordance with the Averaging Period, the effluent meets the following conditions:

  • The average daily CBOD does not exceed 25 mg/L;
  • The average daily concentration of suspended solids does not exceed 25 mg/L;
  • The average daily concentration of total residual chlorine does not exceed 0.02 mg/L, if chlorine or a chlorine compound was used in the treatment of the wastewater; and
  • The maximum daily concentration of un-ionized ammonia is less than 1.25 mg/L, expressed as nitrogen, at 15 °C ± 1 °C.

Acute Lethality (Subsections 11, 15)

Acute lethality must be tested according to EPS 1/RM/13 [1] or EPS 1/RM/50 [2] from a grab sample of effluent taken at the final discharge point. The minimum frequency based on average daily volume deposited annually is shown in Table 1.

Table 1: Minimum Sampling Frequency for Acute Lethality

> 2,500 and ≤ 50,000 Quarterly but at least 60 days after any other sample
> 50,000 Monthly but at least 21 days after any other sample

If a sample is determined to be acutely lethal, the owner or operator must take a grab sample twice a month, but at least seven days after any previous sample to determine whether or not it is acutely lethal.

Averaging Period (Subsection 6 (2))

The average and maximum concentrations are determined at a frequency based on the average daily volume discharged during the previous calendar year (see Table 2).

Reporting (Sections 18, 19, 20)

The owner or operator of a wastewater system is required by the Regulations to submit an Identification Report, Monitoring Report, and if applicable, a Combined Sewer Overflow Report. Reports must be submitted electronically in the form and format specified by the Minister of the Environment. Details on the reporting requirements are in Sections 18, 19 and 20 of the Wastewater Systems Effluent Regulations.

See the Wastewater Systems Effluent Regulations.

Table 2: Averaging Periods Based on Average Daily Volume

Each calendar year ≤ 17,500 Intermittent
Each calendar year ≤ 2,500 Continuous with a hydraulic retention time of ≥ 5 days
Each quarter > 2,500 and ≤ 17,500 Continuous with a hydraulic retention time of ≥ 5 days
Each quarter ≤ 17,500 Any other continuous system
Each month > 17,500 -


[1] Environmental Protection Series, Biological test method: acute lethality of effluents to rainbow trout, Second Edition, Report EPS 1/RM/13, December 2000 (with May 2007 amendments).

[2] Environmental Protection Series, pH stabilization during testing of lethality of wastewater effluent to rainbow trout, Report EPS 1/RM/50, March 2008.