City of Hamilton Identifies Cause of Equipment Failure at Wastewater Treatment Plant – Hamilton | The Canadian News

The city says it has determined the cause of an equipment failure that resulted in the discharge of 353 million liters of partially or untreated sewage into the Port of Hamilton earlier this month.

The incident occurred during heavy rain on October 3, when two of the four bar screens failed at the Woodward Avenue Wastewater Treatment Plant (WWTP), resulting in a complete temporary plant bypass.

The city says it has determined that the plant’s former pump station, which has since been dismantled as a result of capital improvements, was operational at the time due to the high flow.

Excessive solids, such as rags and plastics, are believed to have settled to the bottom of the wet well during idle periods and were drawn through the pumps on the night of October 3, causing the equipment to fail.

The city says the scenario cannot be repeated as the old pump station is now permanently offline as construction of the new main pump station at the WWTP nears completion.

The city adds that it has reported both the incident and its subsequent findings to the Ministry of the Environment, Conservation and Parks (MECP).

This week’s heavy rains also resulted in the temporary diversion of partially treated wastewater from three of the city’s wastewater overflow tanks (CSOs) and the Woodward Avenue Wastewater Treatment Plant.

The city’s website shows that those bypass incidents are now over.

There is no information on the volume of material that was discharged into the basin due to the last wet weather.