August 24, 2007

STANTEC

Ashbridges Bay Treatment odour control facility will begin construction work by summer or fall of 2008.

Improvement

Odour control facility upgrade in design stages for 2008 work

Ashbridges will mix new, old technologies

PETER KENTER

correspondent

TORONTO

Construction work is set to commence on Toronto’s Ashbridges Bay Treatment Plant odour control facility by the summer or fall of 2008. Jason Edwards, a project manager with Earth Tech Canada Ltd., said the company was awarded the estimated $150 million design and construction contract in partnership with Stantec Consulting as part of a process that began in January, 2005.

The objective of the contract is to control odours emanating from the wastewater treatment plant to less than one odour unit — the standard measurement of odour intensity — beyond the facility’s property limit and adjacent to its “M” and “T” sewage pumping stations.

A study commissioned by the city and completed in 2002 had pinpointed the plant’s aeration system as the source of most nuisance odours.

Edwards says that the project could be divided into five smaller contracts that may include:

* Work on the facility’s “D” Building, including an upgrade of its grit and screening facility,

* Work on the “M” and “T” sewage pumping station,

* Work on the existing odour control system, and

* Up to two contracts to update the facility’s aeration tank.

“Earth Tech is looking after the ‘M’ and ‘T’ pumping station upgrades as well as the field house for the redevelopment of the park at Coxwell and Lakeshore near the plant,” says Edwards. “That includes a skateboard park and baseball diamonds. We’ll also be looking at the existing bio-filtration system and odour control. Stantec will be looking after the “D” Building upgrades, and primary treatment and aeration system upgrades.”

To achieve odour control, Edwards says consultants are looking at a mixture of new and proven technologies. “We want to reduce odour from each process area and then capture and treat existing odours,” he says. “We’re looking at proven biological odour control technology — bio-filters and bio-scrubbers as opposed to any type of chemical treatment.”

Bio-filters work by capturing foul air and forcing it through layers of bio-filter media and water before releasing it to the atmosphere.

The project is expected to be completed within a seven to eight-year window from its 2005 inception date, a long-term schedule designed to accommodate both testing of technologies and continued sewage treatment at the plant during the upgrade process.

The first construction activity next year is slated for the facility’s “D” Building and “M” and “T” pumping stations which are already entering the detailed design phase.

“We’re looking at a lot of heavy mechanical work here,” says Edwards.

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