Wastewater Treatment in Hamilton
The City of Hamilton collects and treats both sanitary and combined sewage (wastewater) and currently owns and operates two wastewater treatment plants; one of which is located at 35 King Street in Dundas and the other, which is the largest of the two is located at 700 Woodward Avenue in the City’s east end.
Hamilton’s wastewater collection system consists of both sanitary sewers and combined sewers, (sewers which collect both sanitary sewage and storm runoff into one pipe); combined sewer overflow tanks and wastewater pumping stations. This collection system services the City of Hamilton including the former Towns of Dundas, Ancaster, and Waterdown, the Township of Glanbrook, and the former City of Stoney Creek.
The combined sewer overflow tanks were added to the system as a result of the recommendations from the City of Hamilton’s Pollution Prevention Control Plan which was completed in 1991. The purpose of these tanks is to reduce the number of combined sewer overflows to the local receiving waters. These tanks capture and store excess combined sewage during rainstorms and later send it to the Woodward Treatment Plant where it can be treated after the storm subsides.
The treatment plant at 700 Woodward Avenue is rated at an average daily capacity of 409 Million litres per day. The facility is a secondary conventional activated sludge plant with sludge dewatering and digestion. This operation consists of five main wastewater treatment processes which are: Preliminary Treatment, Primary Treatment, Secondary Treatment, Effluent Disinfection and Sludge Digestion. This plant processes wastewater from the City of Hamilton including the former Town of Ancaster, Township of Glanbrook, and the former City of Stoney Creek.
The 35 King Street wastewater treatment plant is rated at a capacity of 18.2 Million litres per day. The facility is a conventional activated sludge plant with tertiary filtration. This operation consists of five main wastewater treatment processes which are: Preliminary Treatment, Primary Treatment, Secondary Treatment, Tertiary Filtration, Effluent Disinfection . Biosolids are stored on site in covered holding tanks until they are transported via tankers to the Woodward Treatment Plant for further processing. This plant processes wastewater from the former Towns of Dundas and Waterdown.
Both primary treatment sludge, and thickened secondary activated sludge, which are collected from both of the wastewater treatment plants are then processed at the Woodward Avenue Digester Complex. This complex consists of 5 primary and 3 secondary anaerobic digesters. The digestion process utilizes a heated biological process to reduced the volume of organic matter as well as destroy pathogens. This process produces both methane gas which can be used as a fuel or converted into electricity, and treated biosolids which after being conditioned are approved for beneficial use on agricultural land.
In 1987, the International Joint Commission designated Hamilton Harbour as an area of concern as a result of historical municipal and industrial activity. The resulting degraded ecosystem is the subject of remediation efforts developed under the Hamilton Harbour Remedial Action Plan (RAP) that was developed in response to the designation. As part of the focus on Hamilton Harbour, a set of pollutant loading targets for municipal wastewater, as well as for other private and public agencies that impact the harbour, were established. Since that time, many improvement projects and studies have taken place to address the targets that have been identified for Hamilton municipal wastewater treatment and CSO locations. Over recent years, there have been substantial investments made on collection system storage and treatment plant upgrades. It is projected that future planned improvements for municipal wastewater systems over the next 15 years in Hamilton, necessary to accommodate future growth, as well as reduce pollutant loading to meet final RAP targets, will cost approximately $700 million. This work has been planned through the completed phase 3&4 Environmental Assessment (EA) process for Wastewater Treatment and CSO Control in the Woodward Avenue WWTP Service Area. Reporting and public consultation under the EA process was completed in April 2008. The resulting preferred strategy for additional CSO control and improved wastewater treatment reflects significant improvements in wastewater containment and pollutant removal.
In 2006 the City undertook the development of both a Biosolids Master plan as well as Water and Wastewater Master Plan (WWMP). These plans were undertaken from a desire to improve the quality of effluent flowing to Hamilton Harbour as well as the need to respond to growth as defined under the Provincial Places to Grow legislation. As a result of completing the WWMP a formal subcommittee of Council was created to receive updates and provide guidance to staff respecting Council’s involvement with the program moving forward. The committee known as the Woodward Avenue Wastewater Treatment Plant Phases 3 & 4 Class EA Political Subcommittee convenes on an as needed basis to here updates from staff and provide guidance respecting key decisions.