More stringent odour limits proposed for sewage plant

Some Victoria councillors want to see stricter odour limits for the capital region’s proposed new sewage-treatment plant written into the construction contract.

Councillors Jeremy Loveday, Ben Isitt and Margaret Lucas want the wastewater treatment project board to negotiate with contractor Harbour Resource Partners to ensure “enforceable performance standards” are in place once the project is built to ensure odour levels do not exceed two odour units.

An odour unit per cubic metre is defined as the point at which 50 per cent of testers cannot smell the odour using an olfactometer but 50 per cent can.

The councillors want the city to take the issue to the CRD and the project board.

“The project board and the CRD are promising residents that it will be two odour units at McLoughlin, but within the contract it can be up to five,” Loveday said. “So I’m saying, if it’s going to be two, let’s lock that in.”

The councillors also want the board to investigate and report back on the advisability and cost of reducing treatment-plant operating noise levels to 55 decibels.

“Within communication from the project board, they are saying that 60 [decibels] is worst-case scenario. I’d like to know what it’s going to take to not have it be the worst case scenario,” Loveday said. Sixty decibels is considered to be the equivalent of the sound of normal conversation in a restaurant or office.

Loveday added that he has some questions about the project board modelling of how sound from the treatment plant will travel across the outer harbour to James Bay.

“They’re showing that it will dissipate a lot by the time it gets to James Bay and I’ve talked to independent experts in the field who say differently,” he said.

The three councillors are also calling for more consultation with James Bay, Vic West, Fairfield and downtown residents on mitigating the impact of construction of the Clover Point pump station and sewage mains, and close monitoring of geotechnical issues along the Dallas Road waterfront where the piping from the Clover Point pump station is to be buried so that the public can be apprised of any issues that arise.

Chairwoman Jane Bird said the project board will consider the motions if they come forward from the city or the CRD.

Harbour Resource Partners, which includes AECOM Canada, Graham Infrastructure and Michels Canada, was this month awarded a $272-million contract to build the tertiary treatment plant at Esquimalt’s McLoughlin Point — the major component of the CRD’s $765-million plan to have Greater Victoria’s sewage treated by the end of 2020.

Tertiary treatment removes more solids than secondary treatment and most contaminants.

The water produced could be used for landscaping or industrial purposes.

The HRP job also includes installation of a cross-harbour, undersea pipe between Ogden Point and McLoughlin Point and an outfall for treated wastewater at McLoughlin Point.

The contract contains requirements to control odour and noise during construction and operation.