Hamilton, ON – Following the discovery and immediate repair of a hole in a combined sewer pipe spilling into a storm sewer pipe that flowed into the Hamilton Harbour, the City estimates that as much as 337 million litres of sanitary sewage discharged into the Hamilton Harbour over a duration of 26 years.
City staff developed this estimate based on the water meter usage data for all of the properties connected to the combined sewer pipe. There were several ways City staff could calculate the overall estimated volume of wastewater discharged into the Hamilton Harbour, but this methodology was identified as the most accurate representation of the discharge over the time period.
The repair work and realignment of the sewer was completed on Wednesday, November 23, 2022 at 9:32 pm, and all sewage is now flowing into the Western Sanitary Interceptor and all appropriate repairs to the combined sewer have been completed.
The estimated cost of the repair work (excluding staff time) totals $29,830 which includes:
- Excavation and repair/realignment of the sewer – $17,000
- Onsite vacuuming of combined sewer wastewater to stop the spill – $9,830
- Permanent restoration of the road – $3,000
City staff remain in close communication with the Ministry of Environment, Conservation and Parks (MECP) Spills Actions Centre and shared the estimated volume of discharge with them this morning.
There has been some discussion publicly about the possibility of the City receiving an Order from the MECP related to this spill, however, at the time of this news release, City staff have not received one.
City staff will be bringing a report forward today to the City’s Public Works Committee at 1:30 pm and have created a dedicated webpage on the City’s website to ensure that information is shared as it becomes available. For a timeline of events, background and photos, visit: www.hamilton.ca/burlingtonstreetspill
- Hamilton Water has a proactive inspection program of water and wastewater infrastructure in the City.
- On the wastewater side, staff prioritizes these inspections based on different factors, including the highest risk to the environment and age of infrastructure; for example regular inspections are completed at all of the City’s combined sewer facilities and wastewater pumping stations.
- In terms of infrastructure, Hamilton Water manages $14.64 billion in assets which includes more than 1,268 kilometres of sanitary sewer and 573 kilometres of combined sewer, 48,500 maintenance access holes, nine combined sewer overflow tanks and 70 wastewater pumping stations.
- The City of Hamilton has both combined and separated sewer systems. Within the separated sewer system, there are two separate sewer pipes, one for sewage, and one for storm water. The pipe that carries sewage or wastewater is called a sanitary sewer. The sanitary sewer collects wastewater from homes and businesses and takes it to our wastewater treatment plant. The wastewater collected in the sanitary sewer is cleaned at the wastewater treatment plant and then released into Hamilton Harbour.
- Combined sewer systems have one pipe that collects both the wastewater from our homes and businesses, and stormwater from rain or melted snow. Combined sewers send the wastewater they collect to our wastewater treatment plant where it is cleaned and released into Hamilton Harbour.
- However, during wet weather, flows can exceed the capacity of the combined sewer system and combined sewage overflows into local creeks and streams. These overflows are necessary in order to prevent basement flooding and to protect the Woodward Avenue wastewater treatment plant against overloading. In 2021,the average volume of combined sewage discharged from the Wentworth combined sewer outfall untreated was 17,394,000 litres per event
- After preliminary investigation and consultation of City records, City staff believe that the hole was put in a combined sewer pipe in late 1996, as a contractor completing work on a City project was under the impression that all pipes in the area were storm sewers and were designed to directly connect to box culverts leading out to the harbour.
- The catchment area for the combined sewer system services is approximately 50 properties that are tied into the pipe