April 6, 2010

YORK REGION

Working on the Big Pipe extension at 9th Line in Markham, Ontario a tunnel boring machine enters shaft No. 8 at Mingay and 16th Avenue. It is in the process of completing a tunnel 4.5 km long and 2644mm in diameter.

FEATURE | Sewer and Watermain

York’s Big Pipe keeps rolling down the road

Next phase is set for environmental review process as plant readies

IAN HARVEY

correspondent

Little by little the Big Pipe is getting bigger. The next phase in the York Durham Sewer System (commonly known as York’s Big Pipe) is the south east collector.

This section, awaiting ministerial approval of the Individual Environmental Review process, (a more rigorous examination of the impact of the system), will ultimately feed into the Duffin Creek sewage treatment plant in the region of Durham.

The ministry of environment staff approved the plan last fall and after another round of public input, it’s in the hands of the minister, says Daniel Kostopoulos, director of capital planning and delivery in York Region. It is the first sewage line to ever leap through such procedural hoops.

“With water and sewage lines, we usually just go through a municipal class environmental assessment,” he says.

Still, there’s been a curious development in the process. The City of Toronto has hired a consultant to present counter arguments to the configuration in the IEA process.

“I have no idea what they are planning,” says Kostopoulos. “The time for public input on the ministry’s blue book review is passed. It’s all with the minister, so I’m perplexed.”

At the core of the lobbyists’ objections, is the incineration of post-treatment solid waste and the discharge of treated effluent into Lake Ontario, both processes the MOE say meet provincial standards.

An inspection crew is lowered down into the sealed shaft for the Bathurst collector/Langstaff trunk sewer.

As usual for the projects this size, there are always unexpected challenges, says Kostopoulos. The team is still cleaning up after the loss of a $5 million tunnel boring machine in May 2008.

“It’s not for the feint of heart,” he laughed.

The TBM went south when the tunnel collapsed some 22 metres down at the Bathurst/ Langstaff truck sewer project.

While McNally/Aecon kept boring with an identical machine set up on the other end of the tunnel, there were some delays as engineers figured how they were going to extract the buried TBM.

YORK REGION

Working on the completion of the second tunnel from Ninth Line to Ming, a TBM enters shaft No. 4 at Ninth Line and 16th Avenue, to bore a tunnel 3.8 km long and 2644 mm in diameter.

They opted for a five-by-30-metre shaft to get to the 10-metre-long piece of equipment and all its trailing hydraulic, electrical and ventilation lines that stretched another 50 metres behind it.

Then there was the sticky issue of excavating the mud which had filled 300 metres of the already drilled tunnel.

“We hadn’t expected to have to sink that shaft and that caused some delays in 2009 but as of December they were putting a finishing touch on the roadway and laying a temporary asphalt surface which will be redone with the warm weather,” says Kostopoulos.

“Things have been back to normal there with traffic and the sewer work is complete on that section of the line.”

While the whole project is known as York’s Big Pipe, in reality it’s a series of interconnecting projects being completed in several phases. Other phases will likely be added over the next 30 years to meet growth demands.

The Bathurst/Langstaff phase has wrapped up. The interceptor sewer was completed in 2008. The King City sanitary service is also complete with the feed-in sewers being done by the local townships. The terminus of the Big Pipe, the Duffin Creek Water Pollution plant, is well into its expansion to handle the new flow.

The southeast collector is important because it involves adding a parallel line to the existing sewer.

“We need to be able to shut down that line and perform repairs and maintenance, but right now we can’t do that because the flow is too high,” he says, adding it’s an older line and will need attention.

Kostopoulos says the $600 million Duffin Creek segment is on track to deal with liquids by the end of 2010 and the second solid incinerator contract worth some $125 million has been awarded. It qualified for $93 million in Building Canada funding.

“That didn’t actually happen until November because there was a scramble getting the application together for the funding, but they are online now,” says Kostopoulos.

The new boiler buildings are expected to be commissioned soon. The commissioning process for the liquid waste will begin this summer.

Incineration will also be online at the second facility by end of 2010 though there will have to be some tinkering to get flow rates nailed, he says.

In the meantime, all contracts to beef up the haulage roads around the site to handle the heavy traffic have been awarded and work expected to start in the spring.

“We’ve also ordered four new tunnel boring machines and ordered pipe because it takes a while to get these kinds of equipment and materials made and delivered,” he says.

Gatehouses are about to be installed in 2010 to control the flow, says Kostopoulos

Another controversial last minute addition to the plan is the odour control facility, which York Region wanted to put in north Pickering, at Altona and Finch roads. But local activists spurred Durham council to nix the plan.

York then moved it to their side of the border at the intersection of Tauton-Steeles and the 4th Concession. The Region will also install fans to blow any stench away.

Meanwhile, the YDSS team isn’t waiting until the end before starting with the enhancements of Bob Hunter Memorial Park and Rouge Park Master Plan. It includes some $6 million worth of multi-use trails, wetlands, the restoration of the headwater stream entering Hunter Park, archeology and trail mapping.

“All we’re waiting for now is the IEA approval,” he says.

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