Tavistock Wastewater Treatment Plant

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Posted June 24, 2020 | Updated July 23, 2020


Oxford County is upgrading one of the lagoon cells (Cell 1) at the Tavistock Wastewater Treatment Plant (WWTP). This work is needed to ensure the lagoon system continues to operate efficiently and protects the local ecosystem. The project includes:

  • removing the build up of biosolids and sludge;
  • upgrading the aerators that treat sewage and help keep odour under control; and,
  • repairing some of the erosion that has taken place along the banks of the lagoon.

Construction work is scheduled to be completed in the fall of 2020. There will be no interruption to wastewater services during the construction period.


Odour concerns

A well-functioning lagoon system doesn't normally smell, although odour may result from seasonal changes or other temporary situations, like construction. Warmer temperatures and wind direction can also affect odour, and manure spreading at certain times of the year can compound the effect.

Odour from the Tavistock WWTP was more noticeable in May and June because water levels for Cell 1 were deliberately lowered for construction work, which exposed biosolids and sewage to the air. Biosolids need time to naturally dry out and stronger odours can be present when biosolids are first exposed to air.

It is not possible to fully eliminate odour during construction work, and for those living close to the lagoons, odours will be stronger. While we cannot prevent periods of strong odour during construction, we are responding to your concerns.


How we're responding

In response to community feedback about odour, we paused construction in the spring to consider additional odour control measures. This is what we have done so far:

  • Reassessed and updated the construction work plan. We temporarily returned Cell 1 to its normal operating capacity to manage odours to the degree possible. We used Bioxide (calcium nitrate) and hydrogen peroxide to more quickly restore the natural microbial biological action that is needed in the lagoon cell to effectively break down sewage.

  • Installed a new vapour pipeline system. In July, we expanded our odour control system to include a new vapour pipeline system along the lagoon property line. This expanded system blows a dry mist odour neutralizer through pipelines and into the air to bind with odourous materials. It is intended to provide a more effective and longer lasting odour neutralizer that can cover a wider area around the lagoon cells.

  • Took preparations for construction restart. All sewage flows to the Tavistock WWTP are now being diverted into Cell 2. We have relocated surface aerators from Lagoon Cell 1 to Cell 2 to boost performance of this cell to prepare to restart construction on Cell 1. We’ve also set up an automated dosing system for Bioxide for Cell 2 to enhance its biological performance (and odour management capacity) during peak times. We've also left extra aeration time for sewage to break down in Lagoon Cell 1 before resuming construction.

  • Continue to use an odour counteractant. This is an additive that neutralizes smells through a chemical reaction. The County has been using AirSolution™ 9312 Odor Counteractant(External link), a non-toxic, non-corrosive additive that is safe to use in areas where there is human activity. We are also exploring other options.

  • Increased monitoring. We have been monitoring conditions on-site at the lagoon more frequently so that we can adjust lagoon operating conditions where possible and if needed.

  • Provided more information. This project website has been set up to give residents access to information, documents, and the project timeline.


Our commitment to you

Oxford County is committed to providing open and transparent communication throughout the construction period so that residents feel informed. This project page is a place for you to check for information, get project updates, and ask questions. It will be updated throughout the construction period.

You have our commitment that the health and safety of residents and the environment are our primary concern. The Tavistock WWTP is operated in full compliance with its Environmental Compliance Approval from the Ministry of the Environment, Conservation and Parks. All operational practices during construction were reviewed by the Ministry.

We are asking for your patience as we move through the construction process, which is temporary but essential to the continued operation of the wastewater treatment plant. If you have a question you don't see answered on this site, please submit it in the online form below. If you want to speak to someone in person, please call 1-800-755-0394, ext. 3194.



Posted June 24, 2020 | Updated July 23, 2020


Oxford County is upgrading one of the lagoon cells (Cell 1) at the Tavistock Wastewater Treatment Plant (WWTP). This work is needed to ensure the lagoon system continues to operate efficiently and protects the local ecosystem. The project includes:

  • removing the build up of biosolids and sludge;
  • upgrading the aerators that treat sewage and help keep odour under control; and,
  • repairing some of the erosion that has taken place along the banks of the lagoon.

Construction work is scheduled to be completed in the fall of 2020. There will be no interruption to wastewater services during the construction period.


Odour concerns

A well-functioning lagoon system doesn't normally smell, although odour may result from seasonal changes or other temporary situations, like construction. Warmer temperatures and wind direction can also affect odour, and manure spreading at certain times of the year can compound the effect.

Odour from the Tavistock WWTP was more noticeable in May and June because water levels for Cell 1 were deliberately lowered for construction work, which exposed biosolids and sewage to the air. Biosolids need time to naturally dry out and stronger odours can be present when biosolids are first exposed to air.

It is not possible to fully eliminate odour during construction work, and for those living close to the lagoons, odours will be stronger. While we cannot prevent periods of strong odour during construction, we are responding to your concerns.


How we're responding

In response to community feedback about odour, we paused construction in the spring to consider additional odour control measures. This is what we have done so far:

  • Reassessed and updated the construction work plan. We temporarily returned Cell 1 to its normal operating capacity to manage odours to the degree possible. We used Bioxide (calcium nitrate) and hydrogen peroxide to more quickly restore the natural microbial biological action that is needed in the lagoon cell to effectively break down sewage.

  • Installed a new vapour pipeline system. In July, we expanded our odour control system to include a new vapour pipeline system along the lagoon property line. This expanded system blows a dry mist odour neutralizer through pipelines and into the air to bind with odourous materials. It is intended to provide a more effective and longer lasting odour neutralizer that can cover a wider area around the lagoon cells.

  • Took preparations for construction restart. All sewage flows to the Tavistock WWTP are now being diverted into Cell 2. We have relocated surface aerators from Lagoon Cell 1 to Cell 2 to boost performance of this cell to prepare to restart construction on Cell 1. We’ve also set up an automated dosing system for Bioxide for Cell 2 to enhance its biological performance (and odour management capacity) during peak times. We've also left extra aeration time for sewage to break down in Lagoon Cell 1 before resuming construction.

  • Continue to use an odour counteractant. This is an additive that neutralizes smells through a chemical reaction. The County has been using AirSolution™ 9312 Odor Counteractant(External link), a non-toxic, non-corrosive additive that is safe to use in areas where there is human activity. We are also exploring other options.

  • Increased monitoring. We have been monitoring conditions on-site at the lagoon more frequently so that we can adjust lagoon operating conditions where possible and if needed.

  • Provided more information. This project website has been set up to give residents access to information, documents, and the project timeline.


Our commitment to you

Oxford County is committed to providing open and transparent communication throughout the construction period so that residents feel informed. This project page is a place for you to check for information, get project updates, and ask questions. It will be updated throughout the construction period.

You have our commitment that the health and safety of residents and the environment are our primary concern. The Tavistock WWTP is operated in full compliance with its Environmental Compliance Approval from the Ministry of the Environment, Conservation and Parks. All operational practices during construction were reviewed by the Ministry.

We are asking for your patience as we move through the construction process, which is temporary but essential to the continued operation of the wastewater treatment plant. If you have a question you don't see answered on this site, please submit it in the online form below. If you want to speak to someone in person, please call 1-800-755-0394, ext. 3194.