The Guelph Wastewater Treatment Plant (WWTP) provides treatment of domestic, commercial, institutional and industrial wastewater collected from the City of Guelph and the neighbouring community of the Township of Guelph/Eramosa. The facility, located at 530 Wellington Street West, provides tertiary treatment with disinfected effluent being discharged to the Speed River.

The WWTP provides preliminary screening and grit removal, primary treatment by sedimentation, secondary treatment by conventional and extended aeration activated sludge and two stage tertiary treatments utilizing rotating biological contactors (RBC) followed by sand filtration. Disinfection of the final effluent is a requirement and is accomplished by the addition of sodium hypochlorite followed by the addition of sodium bisulphite for de-chlorination prior to discharge to the receiving stream.

Contact information

530 Wellington Street
Guelph, ON
Monday to Friday 8 a.m. – 4 p.m.
Fax: 519-840-2560
After hours emergency: 1-866-630-9242

Sewer abatement credit program

Sanitary sewer main cleaning

Routine maintenance keeps Guelph’s sewer pipes flowing

The City completes sewer main cleaning across Guelph on about a three-year rotating basis.

Cleaning is done year-round, Monday to Friday between 7 a.m. and 5 p.m., and usually takes a few hours on each street.

Map of sanitary sewer cleaning areas

What to expect

  • Toilets, sinks and other appliances can still be used during cleaning.
  • Air pressure in the sewer can create noise in sewer pipes, and may cause water to splash out through toilets, sinks and drains. Keeping toilet lids closed, and sink drains plugged when not in use will help avoid spills.
  • Sewer cleaning can create short-term nuisance odors. Odors can be cleared by opening a window for a few minutes, and running water down sink and bathtub drains, flushing toilets, and pouring a pail of water into basement floor drains.
  • No chemicals are used in sewer main cleaning. High pressure water is used to loosen debris and flush pipes. A high-powered vacuum then removes debris from the pipe, and it’s transported to the City’s Wastewater Treatment Plant for processing and disposal.

What are sanitary sewer mains?

Everything you flush down your home’s toilets and sinks goes to the sanitary sewer main. This includes wasted water from water-based appliances such as dishwashers and clothes washers. Sanitary sewer mains carry this waste to the wastewater treatment plant where it is treated before flowing into the Speed River.

A truck with the City logo is parked in the roadway. Staff in safety clothing are lowering a large tube into a sewer hole in the roadway from which the cover has been removed. There are safety pylons around the truck.

Why we clean sewer mains

Sewer main cleaning helps prevent blockages and backups by removing build-up in the mains including tree roots, grease, grit and sand. This important maintenance work keeps our sewer mains flowing, reduces the potential for nuisance odours, and helps protect our infrastructure.

Sewer main cleaning is also done for CCTV inspection work.  These inspections allow us to see the condition of our sewer mains and make necessary repairs or replacements.

We apologize for any inconvenience during this important maintenance work. Your patience is greatly appreciated.

How you can help

You can help prevent blowbacks and odours in your home by:

  • Occasionally adding water to sink and floor drains to prevent sewer gases from entering your home
  • Checking your plumbing vents each spring and fall for blockages (e.g. bird nests or leaves)

You can also help keep the City’s and your home’s sewer pipes free from blockages by using sinks and toilets properly.

  • Don’t use your toilet or sink as a garbage can. Dispose of garbage, household hazardous waste, medications and all food items, especially grease and oil, properly. Get tips on proper garbage disposal at guelph.ca/waste.
  • Don’t flush those “flushable” products. Flushable wipes and other such products don’t biodegrade and can lead to blockages in sewer pipes.

For more information

Wastewater Services

Help keep Guelph’s sewer system fat-free

Not everything that goes into Guelph’s sewer system will make its way to the Wastewater Treatment Plant. Fats, Oils and Grease, also known as FOG that are poured down the drain or flushed down the toilet can stick to your home’s sewer pipe. Grease cannot be broken down effectively during the wastewater treatment process and cold weather solidifies grease. Just like a steady diet of greasy food can clog your arteries, grease flushed down the pipes blocks sewers. Over time, grease can build up and eventually block an entire pipe, surging up through sinks, floor drains and toilets causing sewage backups and overflows that can cause health hazards, damage home interiors and threaten the environment.

Where does the grease come from?

Grease is a common byproduct of cooking and is found in items such as:
  • Butter and margarine
  • Cooking oil
  • Dairy products
  • Food scraps
  • Lard and shortening
  • Meat fats
  • Sauces

What are the results of a sewer blockage from your home?

A sewer blockage caused by grease accumulation in your home’s sewer pipes may result in:
  • Raw sewage overflowing into your home or your neighbours’ home;
  • An expensive and unpleasant cleanup that often must be paid for by the homeowner;
  • Raw sewage overflowing into parks, yards, streets, and bodies of water;
  • Potential exposure to disease-causing organisms;

What you can do to help

The easiest way to prevent household and environmental damage caused by sewer overflows and backups is to make sure our sewer system is fat-free.

How to dispose of grease properly

  • Never pour grease down the sink drains or toilets.
  • Solidified grease can be scraped into your Wet bag.
  • Liquid cooking oils (e.g. from a deep fryer) can be poured into a container and dropped off at the Household Hazardous Waste Depot.

Tips for keeping Guelph’s sewer system fat-free

  • Scrape solidified grease and food scraps from your plates, utensils, pots, pans, food preparation area and cooking area into your Wet bag or compost pile.
  • Place a strainer in your sink to catch food scraps and other solids. Dispose of grease and food scraps in your Wet bag or compost pile.
  • Use a paper towel to wipe up grease and dispose of the paper towel in your Wet bag or compost pile.
  • Be careful when using a commercial cleaner or detergent which claims to dissolve grease as they may only transport the problem further down the sewer system.
For more information contact the Wastewater Treatment Plant at 519-837-5629 or e-mail wastewater@guelph.ca.

For After Hour Emergencies call 1-866-630-9242.