August 28, 2008

STANTEC

The City of Toronto will rely on odour control technology that has a proven track record, when it comes to its Ashbridges Bay facility. The facility is large and reliability is a key element to its design and construction.

Tender Issued

Ashbridges Bay Treatment Plant in Toronto set to upgrade odour control

Contract will likely include many elements

PETER KENTER

correspondent

toronto, ON

The City of Toronto has released its schedule of RFPs for engineering services on its planned upgrades to the odour control facilities at the Ashbridges Bay Treatment Plant near Coxwell Avenue and Lakeshore Boulevard.

The likely multiple contract RFPs will include:

• Upgrades to its M & T Buildings (raw sewage pumping stations). The work will involve ventilation and heating upgrades, a new activated carbon scrubber and new stacks estimated to cost $8 million. The anticipated tender date is this fall.

• Upgrades to the preliminary treatment plant building, which will include a new grit handling system, new screens, new enclosed truck loading bays, new ventilation and heating systems and new biofilter and stacks. Anticipated tender date is this winter with an anticipated capital cost of $65 million.

• Work on the aeration tanks’ emission air treatment system, to transmit process air to the tall stack. The $16.5 million capital cost project is expected to also be tendered this winter.

• Work on the truck loading biofilter, including replacement of the dewatering equalization tanks scrubber, covering of existing biofilters and construction of a new stack. Anticipated tender date is Fall, 2011, with an anticipated capital cost of $3.5 million.

An RFP with an estimated capital cost of $72 million was put out last month for the facility’s preliminary treatment building upgrades, including a new grit handling system, new screens, new enclosed truck loading bays, a new ventilation and heating system, new bio-filter and stacks and the covering of some primary tanks and venting to the new biofilter.

A further RFP with an estimated $76 million value, currently not on the schedule, involves aeration tank upgrades, including the installation of a fine air bubble diffuser and two contracts for the construction of 11 tank covers.

The construction projects centre on the control of 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. A 2002 study commissioned by the city identified the plant’s aeration system as the source of most nuisance odours in the neighbourhood.

The contracts for the projects, except for the P Building upgrade, will be managed and awarded by Earth Tech Canada Inc. and Stantec Consulting Ltd.

No consultant has been chosen to manage a future project that will involve further covering of P Building tanks.

“The construction contracts will be awarded by conventional public tender,” says Frank Quarisa, Director, Wastewater Treatment, City of Toronto. “We have no intention at this time to introduce a pre-qualification process or any other variation on the traditional public tendering approach utilized by the city.

“Given the amount of operational co-ordination that will be required and the number of technical design issues that will need to be addressed, we want to keep our contractual relationship with the successful contractors as streamlined as possible.”

Quarisa says the facility will rely on odour control technology that has a proven track record. “The D building biofilter will be proven state-of-the-art and based on extensive pilot studies conducted on site,” he says. “The Ashbridges Bay facility is large and complex and therefore our focus is on reliability.

“The emphasis throughout will be on selecting and designing based on the best available technologies that have proven records of performance.”

Because some technology will be tested in pilot projects, the design component of the upgrade will require a considerable investment of time.

“We don’t expect construction until 2011 and 2012,” says Quarisa. “When work commences, it will include a heavy emphasis on all the traditional civil, mechanical and electrical disciplines required to work in a wastewater plant.

“All the work will be tendered to general contractors and we don’t anticipate any specialty contracts at this time. Some of the contracts could include asbestos abatement as a significant portion of the work, for example as part of the aeration tank emission air contract, but this will be left with the general contractors to coordinate.”

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