Intermittently discharging wastewater systems

The Wastewater Systems Effluent Regulations (the Regulations) apply to your wastewater system if:

• it collects an average daily volume of 100 cubic meters (m³) or more of influent in a given calendar year, and
• it deposits effluent into water frequented by fish, or into a place that may enter water frequented by fish

The requirements set out below apply to owners and operators of intermittently discharging wastewater systems that are subject to the Regulations. An intermittent system is typically a lagoon with one to four discharge periods a year.

1) Submit an identification report

An identification report must be submitted and kept up-to-date for each regulated wastewater system. If a wastewater system has multiple final discharge points, one identification report must be completed for each final discharge point.

Information required

• contact details of the owner, operator, contact person and address of the wastewater system
• a statement indicating that the wastewater system is discharging intermittently
• a description of the type of wastewater treatment (e.g. aerated lagoon, facultative lagoon, etc.)
• a statement whether chlorine, or one of its compounds, is used in the treatment of wastewater and if so, a statement indicating a dechlorination system is installed, operated and maintained according to paragraph 6(7)(h)
• a statement indicating which entity owns and which entity operates the wastewater system
• information on the receiving environment (including latitude and longitude) at the locations below:
  • the final discharge point (i.e. the final sampling point location after the treatment process)
  • the point of entry for the final discharge point (where the effluent is deposited into the receiving environment)
  • the overflow points for combined and sanitary sewers (point(s) where excess wastewater is deposit into the receiving environment), if applicable
• the average daily volume of effluent deposited via all of the wastewater system’s final discharge points, expressed in m³
• a statement indicating how the volume is being determined (monitoring equipment or method of estimation) 

Change of information

If any of the information changes, including the contact details for the personal responsible for submitting your reports, you must update your identification report within 45 days after the change.

2) Meet effluent quality standards

To comply with the Regulations, the effluent must meet specific conditions during discharge:

• effluent must not be acutely lethal
• must not exceed the concentration limits of certain pollutants:

*Note on total residual chlorine: Regulatees that use chlorine, or one of its compounds, in their treatment process must install, operate and maintain a dechlorination system.  This is to ensure that the concentration of total residual chlorine does not exceed 0.10 mg/L in a grab sample.

** Note on suspended solids: If you own or operate a lagoon that is experiencing algae or invertebrate blooms, you are allowed to exclude any results of SS that exceed 25 mg/L during four months from May to November when determining the average. The months do not have to be consecutive. If all of the SS results within one averaging period exceed 25 mg/L, the SS average is deemed to be equal to 0 mg/L.

Acute lethality testing must be done in accordance with:

• procedure set out in Section five or six (Single or Multi-Concentration Test) of the Biological Test Method: Reference Method for Determining Acute Lethality of Effluents to Rainbow Trout (EPS 1/RM/13, Second Edition) or
• above Method in conjunction with the Procedure for pH Stabilization During the Testing of Acute Lethality of Wastewater Effluent to Rainbow Trout (EPS 1/RM/50) (section 15)

For more information on acute lethality testing, consult this factsheet. 

Sampling procedure

Samples must be collected at the final discharge point(s). However, CBOD and suspended solids sampling can be done at a location other than the final discharge point if:

• effluent samples are representative as if they had been collected at the final discharge point
• the sampling location and sampling procedure are determined by a licensed professional, and recorded in a document

Note: You can use the results of a sample that was taken in the lagoon two weeks or less before discharge, if the sample was collected to meet a federal or provincial requirement. This sample would count as your first sample during the first 30 days of sampling.

You can collect grab or composite samples to test for CBOD and suspended solids.

All samples must be sent to an accredited laboratory for testing.  

3) Must submit monitoring reports

Monitoring reports are required for each wastewater system on a regular basis. If a wastewater system has multiple final discharge points, one monitoring report must be completed for each final discharge point.

The reporting period is either quarterly or annually depending on the size of the system (see below). 

Information required

• a statement that indicates whether effluent was deposited via the final discharge point during the reporting period
• if effluent was deposited during the reporting period, indicate:
  • the months that effluent was deposited via the final discharge point
  • the number of days effluent was deposited
  • the total volume in cubic meters (m³) of effluent deposited via all of the system’s final discharge points
  • the average CBOD concentration in mg/L at the final discharge point
  • the average SS concentration in mg/L at the final discharge point
    • a statement for each month (to a maximum of four months) from May to November indicating if one or more suspended solids results were excluded from the calculation of the average concentration because they were greater than 25 mg/L due to algae or invertebrate blooms
  • for each sample for which a determination of acute lethality was made at the final discharge point, a statement that indicates:
    • the sampling date
    • the procedure used in Reference Method EPS 1/RM/13
    • whether the pH stabilization procedure EPS 1/RM/50 was used
    • if the sample was acutely lethal 

Monitoring, sampling and reporting information for your specific size of wastewater system 

The average annual daily volume corresponds to the daily volume of effluent deposited via all the final discharge points of the wastewater system during the previous calendar year.

For more information on volume determination, please consult this factsheet.

System’s average annual daily volume ≤ 2 500 m³ 

For each final discharge point:

• volume determination: use either monitoring equipment or a method of estimation based on generally accepted engineering practices with a margin of error of ± 15%
• sampling frequency (CBOD/SS): sample:
  • once during discharge, if the discharge period is 30 days or less
  • every two weeks, but at least seven days after any other sample, if the discharge is longer than 30 days
• averaging period: calculate annual CBOD and SS averages
• acute lethality testing frequency:
  • not required for systems under 2500 m³ per day. If you do test acute lethality for any reason, results must be reported in the monitoring reports
• reporting period: submit a monitoring report once per year, no later than 45 days after the end of the calendar year (due February 14)

System’s average annual daily volume > 2 500 to ≤ 17 500 m³ 

For each final discharge point:

• volume determination: use either monitoring equipment or a method of estimation based on generally accepted engineering practices with a margin of error of ± 15%
• sampling frequency (CBOD/SS): sample:
  • once during discharge, if the discharge period is 30 days or less
  • every two weeks, but at least seven days after any other sample, if the discharge is longer than 30 days
• averaging period: calculate annual CBOD and SS averages
• acute lethality testing frequency:
  • Normal sampling frequency: sample once per discharge event, on the day a deposit begins
  • Increased sampling frequency: sample without delay once a sample is determined to be acutely lethal and do an acute lethality test. Sample every two weeks afterwards, but at least seven days after any other sample, until three consecutive samples are found not to be acutely lethal. Sampling goes back to normal sampling frequency afterwards
• reporting period: submit a monitoring report once per year, no later than 45 days after the end of the calendar year (due February 14)

System's average annual daily volume > 17 500 to ≤ 50 000 m³ 

For each final discharge point:

• volume determination: use either monitoring equipment or a method of estimation based on generally accepted engineering practices with a margin of error of ± 15%
• sampling frequency (CBOD/SS): sample:
  • once during discharge, if the discharge period is 30 days or less
  • every two weeks, but at least seven days after any other sample, if the discharge is longer than 30 days
• averaging period: calculate monthly CBOD and SS averages
• acute lethality testing frequency:
  • Normal sampling frequency: sample once per discharge event, on the day a deposit begins
  • Increased sampling frequency: sample without delay once a sample is determined to be acutely lethal and do an acute lethality test. Sample every two weeks afterwards, but at least seven days after any other sample, until three consecutive samples are found not to be acutely lethal. Sampling goes back to normal sampling frequency afterwards
• reporting period: submit a monitoring report every quarter, no later than 45 days after the end of the quarter (due February 14, May 15, August 14, November 14)

System's average annual daily volume > 50 000 m³ 

For each final discharge point:

• volume determination: use either monitoring equipment or a method of estimation based on generally accepted engineering practices with a margin of error of ± 15%
• sampling frequency (CBOD/SS): sample:
  • once during discharge, if the discharge period is 30 days or less
  • every two weeks, but at least seven days after any other sample, if the discharge is longer than 30 days
• averaging period: calculate monthly CBOD and SS averages
• acute lethality testing frequency:
  • normal sampling frequency: sample once per discharge event, on the day a deposit begins
  • increased sampling frequency: sample without delay once a sample is determined to be acutely lethal and do an acute lethality test. Sample every two weeks afterwards, but at least seven days after any other sample, until three consecutive samples are found not to be acutely lethal. Sampling goes back to normal sampling frequency afterwards
• reporting period: submit a monitoring report every quarter, no later than 45 days after the end of the quarter (due February 14, May 15, August 14, November 14)

4) Submit combined sewer overflows reports (if applicable)

If your wastewater system has one or more combined sewer overflow points, ensure they are entered in the identification report. You must also monitor each point.

For each day there is a deposit, record the:

• date effluent was deposited via an overflow point
• duration or estimated duration of the deposit in hours
• volume or estimated volume of effluent deposited in cubic meters (m³)

Information required for the report

• a statement that indicates whether effluent was deposit each month via each overflow point
• for each month in which effluent was deposited via an overflow point the:
  • number of days effluent was deposited
  • volume or estimated volume of effluent deposited in cubic meters (m³)

Combined sewer overflow reports are due annually, by February 15.

5) Keep records

You must keep all related records on site for a minimum of five years.

6) Apply for authorizations (if applicable)

There are three authorizations that allow the release of effluent that does not meet the effluent quality standards of the Regulations. Authorizations are for specific reasons and are time limited. The authorizations are: 

• Transitional authorization – extension to allow wastewater systems to upgrade their facilities
• Temporary bypass authorization – authorization to exceed the standards of the Regulations for maintenance and construction activities, and
• Temporary authorization to deposit un-ionized ammonia – authorization for systems that have issues with ammonia but are otherwise compliant with the other effluent quality limits.

You can apply for an authorization through the online reporting system.

7) Report unauthorized deposits

Any release of deleterious substances that may enter water frequented by fish and that is not authorized by the Regulations is considered an unauthorized deposit under the Fisheries Act. Unauthorized deposits are subject to specific notification, reporting and mitigation requirements under the Regulations and the Fisheries Act. For more information, please consult the factsheet on Procedures for Unauthorized Wastewater Deposits.

For additional information

Visit the Wastewater website.

If the information you need is unavailable on our website, please contact Environment and Climate Change Canada at eu-ww@ec.gc.ca.

Disclaimer

This information does not in any way supersede or modify the Wastewater Systems Effluent Regulations or the Fisheries Act, or offer any legal interpretation of those Regulations or Act. Where there are any inconsistencies between this information and the Regulations or Act, the Regulations or Act take precedence, respectively. A copy of the Regulations is available.