Did you know, you can’t just discharge any type of water to the sewer?

Sewer Discharge Permits and Agreements are required when private water (water not purchased from the City) is discharged into the City’s sewer system, including storm sewers, sanitary sewers or combined sewers. The City of Toronto’s Sewers Bylaw requires a Sewer Discharge Permit and/or Agreement be obtained and executed before any private water discharge can occur. Examples of private water include:

  • groundwater
  • surface water
  • construction dewatering
  • rainwater (mixed with construction material)
  • stormwater (mixed with construction material)

Once approval is granted by Toronto Water, Discharge Permits and Agreements allow private water to be discharged into the storm sewer, sanitary sewer or combined sewer.

  • All discharge of private water must meet the limits set in the Sewers By-law (See Table 1 for sanitary/combined limits; Table 2 for storm limits).
  • Restrictions to the volume and flow rates may be imposed by the City where warranted by conditions in the sewer.


Permits are issued when:

  • discharge activities will be completed within a short period of duration (generally, one year or less), and
  • the discharge fee will not exceed $20,000.

Examples of this type of activity include site remediation and construction dewatering.


Agreements are issued when:

  • discharge activities are long-term (perpetual), and
  • the discharge fee will exceed $20,000.

Agreements are granted for terms of up to one year and may be renewable. An example is discharge from a permanent private water drainage system.

  • Water discharged to the sanitary or combined sewer requires additional treatment. As such, permit and/or agreement holders will be charged a separate fee based on the volume of private water being discharged.
  • There is no fee for water discharged to the storm sewer; however, the limits set by the Toronto’s Sewers Bylaw for contaminants are stricter and must be met.


Note: If discharging to a storm sewer, that then leads to a combined sewer or sanitary sewer, a fee will be charged for treating that wastewater.

How to Apply

Completed applications must be submitted at least eight to 12 weeks prior to the proposed discharge start date. Incomplete applications will take longer to process.

Download the Private Water Discharge Approval Application

Two copies of the application must be submitted: one by email and one by mail.

Attn: Toronto Water Environmental Monitoring & Protection

30 Dee Ave.
Toronto, ON M9N 1S9
Email: pwapplication@toronto.ca

Amending an Agreement

The requirements for amending a Private Water Discharge Agreement have recently changed. For a list of the latest requirements, please email: pwapplication@toronto.ca