Keep our sewer system chemical and pollutant free

Disposing of chemicals, paints, motor oils, and other pollutants into storm sewer catch basins, sanitary sewers, or on the ground, pollutes our creeks, rivers, and lakes. A spill can also pollute soil, drinking water sources, and harm domestic animals and wildlife.

The City of Guelph Wastewater Treatment Plant does not treat hazardous waste. When these materials are disposed of through the sanitary sewer system, they can inhibit the treatment process at the Wastewater Treatment Plant. Chemicals like concentrated acids and bases can corrode sewer pipes and some flammable chemicals can cause dangerous explosive conditions in the sewers.

What’s the difference between a sanitary sewer and a storm sewer?

sanitary sewer

Sanitary sewers collect sewage and wastewater from toilets and sinks in your home. It is then transported to the Wastewater Treatment Plant Facility via the underground sanitary network where it is treated before being released into the Speed River.

storm sewer

Storm sewers collect rainwater, melted snow, and surface water through storm grates that drain directly into the nearest creek, river or lake. This water is NOT treated. Therefore, when hazardous materials are disposed of into this system, they enter natural drainage channels and can infiltrate the soil and contaminate the groundwater or can be discharged directly into the Speed or Eramosa rivers.

Did you know?

  • Disposing of pollutants into a storm sewer is illegal
  • Any amount of contaminant into a storm sewer is considered a spill
  • One litre of motor oil can contaminate one million litres of surface water
  • Spills can be prevented with secondary containment (i.e. drip pans, absorbents, etc.)

What is a spill?

A spill is anything that is abnormal in quantity and/or quality from a vehicle, structure and/or container. Spills can be substances that are chemical, biological or gaseous in nature, but can also include material, but not limited to, silt, drywall dust, grouting water, cooking grease, and even swimming pool water.

What are the consequences of a spill?

If a hazardous or other material that is spilled into a storm sewer may cause adverse affects to our source water and well water. A spill has the potential to impact people, animals, aquatic life, and other municipalities within the Grand River Watershed.

When containers having pollutant products are buried, they can infiltrate soil and contaminate groundwater. These materials may also be transported by rainwater and/or surface water runoff into the storm sewer system.

Penalties under the City of Guelph By-law for spills may be up to a maximum of $25,000 for persons and $100,000 for corporations, plus the cost of cleanup.


Spills are regulated under the Environmental Protection Act and the Clean Water Act. As well, the City of Guelph Sewer Use By-law (1996) – 15202 governs spills and discharges to the storm and sanitary sewers.

Who is responsible for the cleanup of a spill?

The person having control or ownership of the spilled substance is legally responsible for the cleanup of the substance and the restoration of the affected areas. This includes costs incurred by other parties, including the City of Guelph, acting on their behalf.

How do I report a spill?

In the event of a spill, immediately notify the Ministry of the Environment’s Spills Action Centre at 1-800-268-6060 and/or the City of Guelph’s Environment Protection Officer at 519-837-5629. To assist the Spills Action Centre and/or the City in promptly responding to a spill, you will need to provide the following information:

  • Name of the company or resident and the address of the spill
  • Your name and the telephone number where you can be reached
  • Time of spill
  • Type and volume of material discharged and any other hazards
  • Actions being taken to control/contain the spill

If you observe the discharge of chemicals, oil, paint or any other suspicious materials into a storm sewer catch basin, sanitary sewer or land drainage works (i.e. ditch), call the City of Guelph at 519-837-5629 (24/7).

What to do if you have a spill

As a homeowner, you may use various materials in day-to-day maintenance and repair of your property, homes and vehicles, and in the course of these activities spills may occur.

For a wet spill, such as oil, apply cat litter or another absorbent material; then sweep and place it in your clear bag or grey cart garbage.

If a spill is not hazardous, sweep and dispose of it in the clear waste stream. If you are a City of Guelph or Wellington County resident with hazardous waste, you can bring it to the City’s Household Hazardous Waste Depot at 110 Dunlop Drive, Gate 2.

Residents can dispose of unused pesticides, used motor oils, cooking oils, antifreeze, and other
hazardous products at the Household Hazardous Waste Depot.

Please note: old gasoline is accepted if placed in an Underwriters Laboratories of Canada or Canadian Standards Association approved plastic or metal gasoline container. Replacement containers will be provided, upon request.

For more information and hours of operation, please call 519-767-0598 or visit

For more information

Contact Wastewater Services with questions (8 a.m. to 4 p.m.) or to report a spill 24/7: 519-837-5629, TTY 519-826-9771.

Print-friendly brochure: Keep our sewer system chemical and pollutant free