Wastewater Collection & Treatment

The City of Hamilton collects and treats both sanitary and combined sewage from the large underground wastewater collection sewer system. The City owns and operates two wastewater treatment plants including:

  • Woodward Avenue Wastewater Treatment Plant at 700 Woodward Avenue, Hamilton
  • Dundas Wastewater Treatment Plant at 35 King Street, Dundas

Wastewater collection

Hamilton’s wastewater collection system includes:

  • sanitary sewers and combined sewers
  • combined sewer overflow tanks
  • wastewater pumping stations

This collection system services the city of Hamilton including:

  • Dundas
  • Ancaster
  • Waterdown
  • Glanbrook
  • Stoney Creek

Combined sewer overflow tanks were added to the system 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 Avenue Treatment Plant for treatment after the storm.

Wastewater treatment

The Woodward Avenue Treatment Plant has an average daily capacity of 409 million litres. The facility is a secondary conventional activated sludge plant with sludge dewatering and digestion. There are five wastewater treatment processes used at this plant, including:

  • Preliminary treatment
  • Primary treatment
  • Secondary treatment
  • Effluent disinfection
  • Sludge digestion

The Woodward Avenue Treatment Plan digester complex treats:

  • primary treatment sludge
  • thickened secondary activated sludge

This complex has five primary and three secondary anaerobic digesters. The digestion process uses a heated biological process to reduce the volume of organic matter and destroy pathogens. This process produces methane gas and biosolids. The methane gas is used as a fuel or converted into electricity. The treated biosolids, after being conditioned, are approved for use on agricultural land.

The Dundas Wastewater Treatment Plant has an average daily capacity of 18.2 million litres. The facility is a conventional activated sludge plant with tertiary filtration. There are five wastewater treatment processes used at this Plant, including:

  • Preliminary treatment
  • Primary treatment
  • Secondary treatment
  • Tertiary filtration
  • Effluent disinfection

Biosolids are stored on site in covered holding tanks until they are transported to the Woodward Avenue Treatment Plant for further processing.

View a diagram of the treatment process (PDF, 880 KB)

BioSolids management

The Biosolids Master Plan provides direction for managing biosolids generated from the City’s wastewater treatment plants. Currently all of the biosolids are processed through the Woodward Avenue Wastewater Treatment Plant.  All biosolids from Hamilton are re-used as a land-applied source of nutrient via the City’s land application contractor.

Electricity production from wastewater

Hamilton is the first municipality in Ontario to be accepted to build a generator for sustainable green energy by the Ontario Electricity Financial Corporation. It is also the only wastewater biogas co-generation plant in Ontario with a 20 year contract to sell electricity to the Ontario Power Authority. The project is one of the most innovative, large-scale examples of biogas co-generation in Canada.

This facility aims to:

  • Produce clean renewable electricity from a waste product
  • Reduce greenhouse gas, or GHG, emission to the atmosphere
  • Increase energy efficiency of the facility
  • Generate revenue and reduce operating costs for the existing wastewater treatment plant by producing electricity and utilizing waste heat to offset natural gas usage