Monitoring Wastewater Overflows and Bypasses

Hello Ward 8 Neighbours,

With the Chedoke Creek spill reminding us how precious our Hamilton Harbour and Cootes Paradise watersheds are, and with residents voicing their frustration at the lack of information available, the City of Hamilton has introduced a monitoring site  to inform the public of when a bypass is required and has happened.

For more details, please continue reading below…

Wastewater treatment bypass or combined sewer overflow (CSO) can occur in various ways:

  • Volume of storm water (rain and melting snow/ice) and wastewater exceeds the capacity of the sewer system, CSO storage tank or the wastewater treatment plants
  • When elevated lake levels cause lake water to back-feed into the wastewater collection system
  • Facilitate vital maintenance repairs at the treatment plant or at CSO plants

Wastewater Treatment Plant Operations staff monitor incoming flows and system/plant levels and make operational adjustments to the treatment processes as required.

Operations staff can initiate a bypass or CSO tank overflow event when the system is full to protect the system from infrastructure damage and to prevent basement and/or surface flooding.

The City of Hamilton has a complex network of systems involving various types of wastewater collection. Some networks are separated, others involve combined sewer systems. Separated systems are usually found in newer areas of the city, where as the older areas have combined systems, meaning that they are collecting household waste as well as rain/melt water.

Bypasses and CSO events are necessary to ensure that basements do not flood, as well as  to prevent surface flooding of roads and causing damage to Wastewater Treatment Plants.

To find out more about the city’s real-time monitoring page, click here.

Questions or concerns?

If you have any questions or concerns, you can contact our office here.



Councillor John-Paul Danko