Temporary bypass authorizations

Temporary bypass authorizations (TBAs) allow the owner or operator to bypass one or more treatment processes for a defined period of time, which could result in exceeding effluent limits. TBAs may be issued in the following circumstances:

A temporary bypass can only be authorized from the final discharge point, which is the point beyond which the owner or operator no longer has control over the quality of the effluent. Deposits at points other than the final discharge point are considered unauthorized deposits and not allowed under the Regulations. These discharges may be subject to the notification requirements of subsection 38(5) of the Fisheries Act, and require the person responsible to take all reasonable measure to mitigate the impacts and prevent further damages. Please consult our fact sheet on unauthorized deposits for more information.

To be eligible, you must demonstrate that:

        *Deleterious substances in wastewater are carbonaceous biochemical oxygen demand (CBOD), suspended solids, total residual chlorine and un-ionized ammonia.


You must submit a temporary bypass application in the Effluent Regulations Reporting Information System (ERRIS) no later than 45 days before the start of the bypass (subsection 43).

You must include the following information in your TBA application (section 44):

Bypass explanation:

The bypass explanation should be specific to the wastewater treatment plant, location, work being performed, etc. In ERRIS, you have the option to type in the textbox or attach a separate file.

You can send additional information to Environment and Climate Change Canada (ECCC) at eu-ww@ec.gc.ca. Please ensure the owner/operator and system name are in your email, and clearly state that the information pertains to a TBA application.

To guide you in your application, please consider the following questions which ECCC may ask you as part of its assessment:

Why is the TBA requested

For maintenance work: why is it needed? Is this work reoccurring? For construction work: why is it needed? What are the expected outcomes as a result of this work? Is better effluent quality expected after the work is completed?

How is the work planned to be undertaken

What level of wastewater treatment is expected over the course of the bypass? If the bypass is raw wastewater, is influent quality data available? What options were considered to avoid the bypass? How was the proposed approach decided on? What public outreach is planned regarding the bypass? What outreach is planned to Indigenous communities that rely on the waterbody?

Environmental Factors

Are there any environmental factors that were considered when planning the bypass? Why was the bypass planned for the period requested? Please ensure the name of the waterbody at point of entry and description of water use listed on your identification report is accurate.

The information and questions may not all be applicable to your request. Please consider the level of treatment, duration and volumes proposed to be released when submitting an application. 

Should extenuating circumstances out of your control change the period of the bypass, you may apply for a new temporary authorization with corrected dates or for an extension (subsection 47(2)). To do so, please contact us to provide the pertinent information.

Refusal of temporary bypass authorization

Your TBA application can be refused if:

 WSER amendments – proposed changes to temporary bypass authorizations

ECCC is proposing to expand the existing TBAs in the Regulations to include planned releases of wastewater from sewer systems. For more information and to share your thoughts, please visit Share your ideas: Consultation on amendments to the Wastewater Systems Effluent Regulations.

 Contact us

If you require further assistance or have any questions, please contact Environment and Climate Change Canada at eu-ww@ec.gc.ca .


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.

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