About Wastewater

Wastewater is any water that leaves a home or building through a drain such as a toilet, sink, bathtub, dishwasher or washing machine. Wastewater from homes and buildings connected to the municipal sewer system travels through underground pipes to a wastewater treatment plant for treatment before returning to the local river system. If you live on a farm or in a rural area you probably have your own septic system. Septic systems are the responsibility of the property owner.

Each day, Region of Waterloo wastewater plants treat about 155 million litres of wastewater - enough to fill about 3,600 backyard swimming pools. As Waterloo Region grows, this amount continues to increase. The Region is continuously planning, expanding and upgrading our wastewater treatment infrastructure to meet that growing demand while protecting our natural resources.

It takes wastewater about 24 hours to travel through a multi-stage treatment process. The solid material is treated separately from the liquids. Digesters produce biosolids by breaking down the solids and killing potentially harmful micro-organisms over a period of weeks. The liquids are treated and returned to the local river system.

The Region of Waterloo owns 13 wastewater treatment plants, seven pumping stations and a de-watering facility. The Region of Waterloo oversees operation of these facilities by the Ontario Clean Water Agency (OCWA).

Help keep stormwater out of sanitary sewer pipes

Stormwater does not receive the same treatment as wastewater. Stormwater is rainwater or snow melt that travels into drainage systems before returning to the local river system without treatment. The cities and townships are responsible for stormwater management.

Help keep stormwater - such as rain, basement sump pump discharges and foundation drainage - out of sanitary sewer pipes. Do not connect stormwater discharge pipes to the sanitary sewer system. Proper drainage of stormwater helps to:

  • Reduce costs by keeping treatment for wastewater only. Stormwater does not require the same level of treatment as wastewater
  • Reduce stress on pumping stations and treatment plants. Water from sump pumps or other drains mistakenly connected to the sanitary system will increase flows into wastewater treatment plants and increase the risk of a sanitary sewage backup into homes and businesses
  • Reduce environmental impacts. While we design our wastewater treatment plants to address storms, a larger storm may cause untreated or partially treated wastewater to end up in the local river system as a result of increased flows at pumping stations and treatment facilities
Protect your pipes: what not to flush or pour down the drain

Find out what you can do to protect your pipes. What you pour down the sink or flush down the toilet can be costly. It can lead to blocked pipes in your home, costly plumbing repairs and flood damage from sewage backups in your basement. It can also be costly for municipal wastewater treatment equipment including blocked sewer pipes and buildup on wastewater handling equipment requiring unscheduled maintenance.

Sewer Use By-law, environmental enforcement and spills response

The Ontario Ministry of the Environment, Conservation and Parks strictly regulates the design and operation of our treatment plants. Each Regional plant must meet strict environmental quality standards set by the Ministry of the Environment, Conservation and Parks. The Region of Waterloo monitors the treated water leaving our wastewater treatment plants to ensure our facilities meet the standards and are not harming the natural environment.

The Sewer Use By-law 21-036 regulates and controls the discharge of water and wastewater into the sanitary and/or storm sewer distribution system within Waterloo Region. The by-law protects the wastewater treatment system and the water quality of the Grand River. You can use this online form to apply for a permit under the Sewer Use By-Law.

The Region of Waterloo provides 24-hour emergency response to environmental spills. Responsibilities include a prompt investigation of reported spills, containment or cleanup measures to minimize damage to the natural environment and notifying affected parties if a chemical spill could affect the Region of Waterloo Mannheim and/or Brantford drinking water treatment plants. Report a spill immediately if you witness or suspect a spill has occurred or is about to occur.

Wastewater surveillance dashboard

View the wastewater surveillance dashboard for Public Health wastewater monitoring of COVID-19, influenza and respiratory syncytial virus.

Biosolids strategy
A treated solid, known as biosolids, has many uses. For example, it can be applied to agricultural land as fertilizer, used to restore mining sites, or taken to the landfill for disposal. The Region of Waterloo is currently developing a new Biosolids Strategy and we need everyone's involvement to help identify the best possible solutions.
Privately hauled wastewater and septic systems

Not all residences and workplaces in the Region are connected to municipal sewer systems. Many rural communities and small settlement areas rely on privately-owned septic systems to treat and dispose of their wastewater. Septic systems are the responsibility of the property owner. 

The Region of Waterloo accepts sanitary discharges from pre-approved licensed commercial haulers that clean out privately owned residential septic tanks and portable toilets.

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