September 18, 2008

AQUATECH

A crew from Aquatech assembles their equipment at the site of a plugged sanitary sewer line that threatened to overflow.

Aquatech team springs to action over plugged sanitary-sewer line

PETER KENTER

correspondent

A plugged sanitary sewer line is no laughing matter — especially when combined with an expected rain storm and an environmentally-sensitive landscape. That was the situation faced by the city of Markham and York Region last spring as a plugged line threatened to overflow into the Rouge River watershed.

Aquatech, a Markham-based contractor specializing in rapid response to such situations, picked up the emergency call around 1 p.m. on Thursday, May 29. A company rep arrived at the scene near Highway 7 at the Rouge River a few minutes later to assess the situation. The sanitary line had been damaged as a result of construction activity on a condominium development.

“They accidentally drilled through the sewer main while doing tie-backs and that’s what caused the blockage,” says Norm Metcalfe, Aquatech branch manager. The weather forecast predicted a storm the night of the next day, giving the company just over 24 hours to install a bypass around the affected sewer.

Basing their response on historical flows, a pump specialist identified the equipment requirements and devised a first response plan. Aquatech site representatives worked with municipal engineers to locate access holes that could be used to create the bypass.

“This was a classic sewer bypass — out of one manhole, around the problem area, and into another,” says Andy Ingriselli, president of Aquatech.

AQUATECH

Diesel-powered pumps are connected to lines used to bypass the blockage.

Aquatech planned to ship in two primary critically-silenced diesel-powered pumps, as well as two secondary standby diesel-powered pumps, each weighing as much as 8000 kilograms. “We keep a large inventory of pumps and pumping equipment for emergencies like this,” says Ingriselli. “It’s not the type of business where you can go out and rent the equipment you need.”

Emergencies are often so demanding that the contractor often doesn’t know who will be footing the bill for the job beforehand. “We’re not concerned who the client is at the start of the job,” says Metcalfe. “We don’t even have the time to quote on a job like this. All of our pricing is standard in an emergency. We often don’t even know who will be paying the bill until later.”

A 20-tonne boom truck was dispatched to deliver the pumps to the site. The first load of pumping equipment was delivered to the site by 3 p.m., the second load by 4 p.m. and the final delivery an hour later.

With pumps on site, Aquatech worked with municipal staff to locate site constraints. Access holes, for example, often require additional equipment, including pipes, hoses, special fittings and adaptors. For this application, the access holes had to be fitted with special risers. Municipal engineers co-ordinated support from other trades to prepare the site and provide a safe work area for the temporary pumping station.

By 7 p.m. Thursday, the discharge piping for the bypass system was laid out behind the road barriers, but final set-up of the pumps had to wait for road access permits. When the permits arrived Friday afternoon, barriers were set in place and access to the manhole began. Crews worked through the night to prepare the site and by 5:00 p.m. Friday the system was commissioned and operational.

The storm? It arrived later that night, dumping enough rain on the site to have caused the environmental disaster that everyone had feared. The bypass performed flawlessly.

“You need a large pumping fleet and rapid service to respond to this type of emergency” says Ingriselli. “Nobody even comes close to us.”

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