Wastewater

Discharge Permits for Private Water (e.g. groundwater, surface water etc.)

Sewer discharge permits/agreements are issued by the Environmental Monitoring & Protection Unit of Toronto Water.

These permits/agreements are required when private water (water not purchased from the City) is discharged into the City sewer system. Some examples of private water include:

  • groundwater
  • surface water
  • rainwater
  • stormwater
  • construction dewatering
  • water directly taken from a body of water (e.g. Lake Ontario)


Private water can either be discharged into the sanitary sewer or storm sewer. Private water discharged into either sewer system must meet the bylaw limits specific to that sewer system but private water discharged to the sanitary sewer also requires treatment, therefore a separate fee is applied to the volume of private water being discharged.

Discharge agreements are issued for long-term discharge, such as a manufacturer drawing on Lake Ontario water for their production and discharge permits are issued for short-term discharge, such as a construction site temporarily drawing on groundwater.

As per the Sewers Bylaw, in order to issue a discharge approval, information relating to the quality and quantity of the discharge must be provided to Toronto Water. It is strongly recommended that the applicant provide this information eight to twelve weeks prior to the proposed start of discharge using the Private Water Discharge Approval Application. The application form must be completed and sent to pwapplication@toronto.ca for review. 

For information about application requirements and guidelines for permits and agreements, email pwapplication@toronto.ca or call 416-338-7471.

The Sewers and Water Supply Bylaw Compliance and Enforcement Annual Report contains more information on the above agreements/permits.

Construction Wastewater, Waste and Debris Disposal

Construction wastewater, waste and other debris should not enter the storm sewer as any water entering the storm sewer is released, untreated, into the nearest stream/river. Keeping construction wastewater, waste and other debris out of the storm sewer helps prevent storm sewer blockage, damage to the sewer system, road flooding and harmful substances from entering local waterways where it can harm aquatic habitat.

To prevent construction debris from entering the storm sewer system:

  • Wash vehicles off-site at a car wash/truck wash or establish a designated wash area on-site.
  • Design an effective construction exit to prevent dirt and waste leaving the site – this may include gravel, paving, rumble strips and wheel washing.
  • Ensure cement/ready-mix trucks do not hose down onto the roadways or into catch basins.
  • Do not allow any dirt from the site to be dragged out to City roads.
  • Do not allow any wash water from the site to runoff into catch basins.
  • Change vehicle oil and antifreeze off-site at designated facilities.
  • Ensure your company has an Erosion & Sediment Control Plan and follow it. Implement measures to keep sediment in place where soil is being disturbed by the construction processes, such as the use of sediment traps, storm inlet protections, fibre rolls, silt fences, etc.
  • Where land is being cleared, protect catch basins by covering the inlet with filter fabric or follow another approved method which will not allow sediment to enter the catch basin.
  • Maintain good housekeeping by properly disposing of all construction debris.
  • Do not power wash construction dirt and waste onto the roadways or into catch basins.
  • Regularly sweep streets, sidewalks and driveways using dry method/vacuum sweepers and dispose of waste properly.
  • In the event of a spill, ensure equipment and processes are in place to keep prohibited materials out of the storm sewer. If materials enter the storm sewer system, call 311 to report the spill.

Do not allow these materials to enter the storm sewer system through catch basins:

  • Mud/sand
  • Concrete/cement powder
  • Paint
  • Oil/petroleum products
  • Soap
  • Chemicals
  • Any construction material, debris or dust

Construction wastewater is any non-purchased city water (private water) that is running off a construction site and this includes:

  • Groundwater
  • Rain water
  • Muddy water
  • Collected water
  • Runoff water

Construction wastewater requires an approved discharge permit from the City. If construction debris or construction wastewater from your site gets into the storm sewer you may be fined or charged under the Sewers Bylaw (Municipal Code Chapter 681-Sewers).

For a brochure on the above information, click here.


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