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Wastewater Services

 Wastewater Emergency Pager 705-446-5041

The Town is responsible for providing municipal wastewater services to connected properties.

Are you looking to connect your dwelling to municipal services? Please visit our Planning & Development Services page for additional information.


The Town places high value in protecting the natural environment and local waterways. As such, the Town is committed to posting information about sewage by-pass and overflows to the Town website within one business day of such an occurrence.

A sewage overflow occurs when wastewater from the sanitary collection system overflows to the natural environment or when there is a discharge of partially treated sewage from a wastewater treatment plant, often as a result of excessive groundwater and stormwater entering the system during heavy rains, rapid snowmelt or a pipe break.

The Town’s sanitary collection systems are nominally separate, meaning that sanitary and stormwater flows are carried in different pipes with different destinations, however stormwater inflows and infiltrates into the sanitary system from numerous sources.

Wastewater by-passes and overflows within the Town’s sanitary system are extremely rare.

Reporting to Ministry of the Environment & Climate Change

By law the Town is required to report sanitary by-passes and overflows to the Spills Action Centre, Ministry of the Environment and Climate Change and the Medical Officer of Health, Grey Bruce Health Unit. The notification includes the following information:

  1. Date, time and duration of the Event
  2. Location of the Event
  3. Measured or estimated volume of the Event
  4. Reason for the Event
  5. Level of treatment the by-pass and/or overflow received and disinfection status of the same

This information is currently captured in the Town’s annual reports for the wastewater treatment facilities. The Town’s 2017 annual reports are available for download.

2017 Craigleith Wastewater Treatment Plant Annual Performance Report

2017 Thornbury Wastewater Treatment Plant Annual Performance Report

Overflow & By-Pass Map

Craigleith Collection System and Facility Map

Thornbury Collection System and Facility Map

Sewer By-Pass & Overflow Logs

Recent Wastewater Treatment Plant Overflow Event 




Volume (m3)

Precipitation (mm)

April 29, 2019

Thornbury WWTP

Overflow of Cell #3

1,620 cubic meters


Recent Wastewater Treatment Plant By-Pass Events, 2017 to Present

No events to report.

The Town designs and upgrades its wastewater collection systems and facilities to ensure adequate storage capacity and minimize the risk of by-passing and overflow events. All infrastructure work within the Town must adhere to the Town’s Engineering Standards and provincial requirements.

Reducing By-Passes & Overflows

The Town is currently undertaking work to complete a sanitary collection model which will enable Staff to identify existing system deficiencies and create a capital improvement plan aiming at reducing and replacing undersized and substandard infrastructure.

Frequently Asked Questions

Is receiving water tested during/after a sewer overflow or by-pass? The receiving water is not tested during or after a wastewater overflow or by-pass. It takes at least 24 hours for a laboratory to analyze water samples therefore results would not represent the current status of the water.

Do by-passes and overflows affect drinking water quality? Town of The Blue Mountains adheres to provincially regulated drinking water quality standards. More information about drinking water quality is available in the 2018 Annual Water Report.

The Town's Wastewater Operators are responsible for overseeing the treatment of wastewater generated by The Blue Mountains.

The treatment process consists of pre-treatment, aeration, clarifiers, digesters, tertiary, and effluent UV disinfection.

The Craigleith Wastewater Treatment Plant is an extended aeration modification of the conventional activated sludge sewage treatment process. This form of treatment was selected to allow for the fluctuating loads associated with the recreational/seasonal residential area that is being serviced by the plant, and to limit the quantity of sludge generated by the plant. The treatment process selected (extended aeration) produces a very low volume of sludge compared to a conventional activated sludge plant.

The Thornbury Wastewater Treatment Plant is an extended aeration version of the activated sludge process.  The facility incorporates pre-treatment, aeration, clarifiers for settling and U.V. effluent disinfection.  Waste sludge is stabilized in a lagoon followed by an effluent polishing pond.

Wastewater Services include:

Craigleith Wastewater Treatment Plant, with a service area bound by Hidden Lake Road to the west, Grey Road 21 on the east and the Blue Mountain Core Development. In this area are three pumping stations and one main lift station that delivers all the liquid waste to the treatment facility.

Craigleith Service Area Map

Thornbury Wastewater Treatment Plant service area is Lora Bay on the west and Hidden Lake Road on the east, including Thornbury, Camperdown, Peaks Bay and Delphi Point. In this area are six pumping stations with two main lift stations that deliver all the liquid waste to the treatment facility.

Thornbury Service Area Map

The effluent from The Blue Mountains' treatment facilities is required to meet strict parameters established by the Ministry of the Environment and Climate Change for discharge to receiving waters.

Due to the sensitivity of the receiving body of water (the Mary Ward shoals area of Georgian Bay), the treatment process is required to produce a high quality effluent with a low level of phosphorus. In order to reduce phosphorus to the required level, it is necessary to apply a chemical coagulant (alum) and to provide tertiary treatment of the plant effluent prior to discharge. The tertiary treatment in this plant is achieved with gravity flow filters.

Where Does My Water Go Once it Goes Down the Drain?

If you are connected to the Town's wastewater collection system, all the sanitary drains in your home are linked to a single pipe (called a lateral) that runs underground from your home to the roadway. At the roadway, the lateral connects to a larger pipe (called a trunk) and is directed to a wastewater treatment plant.

If you have questions about consumption charges or your utility bill please contact the Town’s Utility Account Coordinator.

For information on wastewater rates please visit our Financial & Information Services page.

Materials that Should Not Enter the Sanitary Collection System

Household items such as disposable (flushable) wipes, baby wipes, dental floss, rags, plastic bags, condoms, band aids, cotton balls, cigarettes, pharmaceuticals and feminine products should not be flushed down the toilet. These items can block wastewater collection lines and clog pumps, causing damage that can be expensive to repair. Keep it simple only flush the 3 P's pee, poop, (toilet) paper. 

Grease, fat and cooking oils should not be poured down drains. Continuously pouring these materials down drains can cause build-ups to form on the sides of pipes, which can cause blockages in the wastewater collection system. These blockages can lead to messy and expensive wastewater back-ups into basements, yards and roadways.

To avoid these problems, scrape all grease, fats and cooking oils into a rigid container, allow the materials to solidify and dispose of them in your regular garbage collection or in your curbside organics bin. Sink baskets and strainers should also be used to prevent food residues from entering your drains.

Do not pour any household hazardous chemicals or toxic materials down drains, as these materials can be difficult to treat and end up entering the natural environment.

Sewer Use By-law

By-law 2013-37 being a By-law to Regulate Sewer Discharge in the Town of The Blue Mountains is available for download.  

For more information please contact the Town's Compliance and Efficiency Coordinator.

If you are looking for information on privately owned septic systems, the Grey Bruce Health Unit is responsible for managing this type of system.


Manager of Water & Wastewater
519-599-3131 x226

Wastewater Supervisor

Water & Wastewater Services
519-599-3131 x284