Wastewater Overflow Event | March 7–8, 2026
The Town is advising residents of a wastewater overflow event that occurred between March 7 and March 8, 2026, at the Wastewater Treatment Centre (WWTC).
A rapid temperature increase combined with significant rainfall over the weekend caused unusually high inflow and infiltration in the wastewater system. This, along with challenges associated with legacy combined sewer infrastructure, resulted in an overflow of partially treated wastewater. Event details:
- Start: March 7, 2026 at 4:05pm
- End: March 8, 2026 at approximately 1am
- Total volume released: 2,600 cubic metres
Inflow and infiltration (I&I) refers to excess stormwater and groundwater that enters the sanitary sewer system and takes up treatment capacity intended for wastewater.
As required under provincial regulations, the Ministry of the Environment, Conservation and Parks and the Medical Officer of Health were notified immediately. All mandatory reporting procedures were completed. There is no action required by the public at this time. The Town continues to monitor system conditions closely.
Events like this serve as a reminder of the ongoing need for strategic and proactive investment in the replacement and rehabilitation of aging linear infrastructure. With changing weather patterns and increasingly unpredictable conditions, modernizing these systems is essential to mitigating future overflows, protecting the environment, and maintaining resilient wastewater operations.
In recent years, the Town completed an I&I study and a Wastewater Master Plan to better understand where system challenges exist and how to reduce excess flows. These studies provided a clearer picture of aging infrastructure, areas with elevated I&I, and capacity pressures during peak flow conditions. Their findings continue to shape the Town’s approach to source control measures, long term capital planning, and overflow reduction strategies.
The Town is now implementing priority system upgrades, including the Wastewater Treatment Centre Headworks Upgrade Project, which will enhance treatment capacity, improve overall system reliability, and help mitigate future overflow events.
Visit midland.ca/sewers to learn more about sewer overflows, wastewater treatment, and inflow and infiltration.