Diagram of twin tunnels.

Drilling work finished on costly Metro water tunnels

Key milestone for mega-project that went over budget

After years of litigation and major cost overruns for Metro Vancouver, drilling work is now finished on twin water tunnels deep inside Grouse Mountain.

A tunnel boring machine broke through to daylight Friday morning, marking a key milestone in the $800-million Seymour-Capilano Filtration Project.

It’s a moment of relief for Metro Vancouver politicians, who fired original tunneling contractor Bilfinger Berger after it halted work in early 2008, saying crews encountered unstable rock.

Metro retendered the contract and a different firm finished the job.

“We’ve made great progress, despite some unexpected challenges,” Metro water committee chair Tim Stevenson said, referring to the tunneling delay.

“Another contractor has completed the tunnel boring work, using the original engineering designs and the same tunnel boring machines as the former contractor.”

The filtration plant itself started filtering water from the Seymour reservoir more than a year ago.

But it’s expected to take until 2013 before more additional work is done to complete the tunnels and begin filtering water from the Capilano reservoir as well.

The cost of the tunnels went $170 million over the original budget, but Metro is suing Bilfinger over the contract termination and could recover some costs if it wins a trial slated for late 2012.

The tunnels are four metres in diameter and about seven kilometres long.

The system, which also disinfects using ultraviolet light and chlorine, should eliminate rare bouts of turbid, cloudy water that sometimes occur when storms or mudslides stir up silt in the North Shore reservoirs.

There’s conflicting evidence as to whether the discoloured water at such times poses any real elevated health risk or just looks unappealing.

The Seymour Capilano Filtration Project is one factor pushing up regional taxes and that’s also part of the reason Metro has been urging residents to use tap water rather than bottled water.

Once Capilano is on stream, the plant will filter up to 1.8 billion litres of water a day, serving 70 per cent of Metro Vancouver residents.

Metro’s eastern suburbs get their water primarily from the Coquitlam source, rather than the North Shore.

Work begins this summer on a $110-million ultraviolet light disinfection plant for the Coquitlam reservoir. That project is to be finished by late 2013, when advanced treatment should be in place for all three Metro reservoirs.

The water projects are major factors driving up regional taxes and water fees.

Metro water rates are expected to rise 40 per cent to $300 per household by 2015.