April 27, 2009

The Betty Lake Water Treatment Plant was built in 1952 and is in line for some major upgrades.

Betty Lake Water Treatment Plant upgrade benefits CFB Wainwright

Stephen Dafoe

correspondent

Edmonton

An upgrade to the Betty Lake Water Treatment Plant at CFB Wainwright, 200 kilometres south-east of Edmonton, will improve the quality of drinking water for both the military base and the neighbouring town.

The $11.4 million project, presently out for tender, calls for a 12.5 by 16.3 metre addition to be built on the south side of the existing facility to house a Zenon-GE immersed membrane system.

The new filtration system will help treat about 1.4 million cubic metres of water that the plant draws each year from the nearby Battle River.

The need for an upgrade was identified in a 2007 study by the Canadian Environmental Assessment Agency, which determined that the source water coming from the Battle River contained high concentrations of Giardia and Cryptosporidium cysts from wildlife and cattle.

As such, it was determined that a multi-barrier approach was required to prevent the raw water pathogens from reaching the water taps of the town or base.

Stephen Pelkey, chief operator for the Betty Lake Water Treatment Plant, said that the decision to go to the new system is the culmination of five years of studies, including a six-month pilot project with the immersed membrane system.

“A lot of studies have gone on (as to) whether we should get rid of our conventional filtration and just go straight to membrane – should we keep the chemical soup, if you will, in front of that,” Pelkey said, adding that the 1952 built water treatment facility currently uses a conventional dual media or gravity filter system.

“With a little bit of pushing from our end, the operations end, we decided that we would keep our conventional filters and then go to the membrane as a polishing,” said the chief operator.

The Cryptosporidium oocysts and Giardia cysts that are being transported along the 2.2 kilometres of pipe from the Battle River to Betty Lake measure in the 1 to 7 micron range.

Because ultrafiltration membranes generally have a pore size of 0.01 microns, Pelkey explained that the immersed membrane system is ideal for polishing, as no known cyst, oocyst or virus can penetrate it.

“So if you want to think of it as a hollow strand of spaghetti or a straw, what we do is create a vacuum – we suck the raw water if you will through the membrane into the centre of the straw,” he said.

“That’ll go to a tank and be chlorinated and that would be your finished product. It should guarantee 99.999 per cent stripping of the cysts and oocysts.”

Pelkey explained that 80 per cent of the water treated by his plant is used by the town with the remaining 20 per cent being used on the base.

But the extra treatment of the water will create extra effluents.

Additional process waste from the immersed system will be released along with current waste into the existing lagoons, which, depending on the nature of the filtration process, are either channeled into the north slough or back to Betty Lake.

However, the Department of National Defence has committed to improving the handling of discharged processed waste.

“Now that we’re looking at new treatment processes, we looked at our effluence – our discharges – to see what we could do, and realized that was an issue and have decided to go with engineered lagoons,” Pelkey said, adding that existing facilities are the original dugouts.

“We had hoped to put that part and parcel with that project because we need one after the other,” he said. “We weren’t able to do that, but Alberta Environment assured us that if we got the membranes up and running – because we didn’t have the effluent management in place yet – they wouldn’t stop us from using the membranes, as long as it was in place and was going to be built.”

Pelkey anticipates that the engineered lagoons will be built within a year of the completion of the treatment plant addition.

The Wainwright water treatment project is one of three defence infrastructure projects announced by the Minister of National Defence, Peter MacKay, during a visit to Edmonton on March 15 and it is anticipated that the CFB Wainwright upgrade will create as many as 61 construction jobs during the course of the project.

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