Chedoke Creek spill update: City of Hamilton receives additional Orders from Ministry of the Environment, Conservation & Parks

The City of Hamilton, Ontario recently received an additional Provincial Officer’s Order from the Ontario Ministry of the Environment, Conservation & Parks (MECP) as they relate to a spill into Chedoke Creek.

In 2019, the MECP ordered the City to complete an Environmental Risk Assessment of Chedoke Creek and an Ecological Risk Assessment for Cootes Paradise. These studies both found that it was not possible to attribute environmental impacts experienced in these areas exclusively to the spill.

The most recent Order from the Ontario Environment Ministry requests that the City undertake remedial action for Chedoke Creek and Cootes Paradise. In part, the Order asks that the City develop a plan for targeted dredging in Chedoke Creek and recommends mitigation measures to improve water quality in Cootes Paradise.

The City stated that it is committed to continuing its full cooperation with the MECP’s investigation and staff will be consulting with Council regarding how we can best address the environmental concerns in Chedoke Creek and Cootes Paradise.

To date, in response to the spill, the City has taken a number of actions toward addressing the impacts of the discharge, including:

  • Undertaking clean-up of the creek, including removing 242,000 litres of “floatable material” from the surface and edge of the creek.
  • Initiating regular monitoring of water quality in impacted areas of Chedoke Creek.
  • Initiating and implementing enhanced inspections of wastewater facilities and equipment.
  • Undertaking expert studies to determine what kind of further remediation is appropriate for Chedoke Creek and Cootes Paradise.
  • The approval of four new staff members to increase the City’s ability to perform regular, routine physical inspections and preventative maintenance for City water infrastructure, as well as sampling and analyzing water and wastewater quality in Hamilton.

Background Information

In July 2018, the City of Hamilton informed the public that it had discovered that one of its combined sewer overflow tanks was discharging untreated wastewater into Chedoke Creek. The City immediately stopped the discharge and began clean-up activities in the area.

Over the course of a four-and-a-half-year period, the City estimated that approximately 24 billion litres of combined storm water runoff and sanitary sewage was discharged into Chedoke Creek. This represents approximately four per cent of the annual volume of flow to Hamilton’s wastewater treatment plants.

Investigations have determined that the spill was the result of two separate malfunctions at the Main/King combined sewer overflow tank. First, a station bypass gate in the combined sewer overflow tank that should have been in a closed position appears to have been manually opened to approximately five per cent on January 28, 2014. An error in computer programming showed this as normal operation and, as such, this error remained undetected until July 2018. Additionally, a second gate that should have remained in the open position experienced a mechanical failure in January 2018. The sensor on this piece of equipment did not pick up the failure and was reporting normal operation. Despite extensive investigations, the City has not been able to determine why the first bypass gate had been opened in January 2014.