Tuesday, September 20, 2005

Devils Lake outlet shut until spring?

By Mia Rabson and Paul Samyn

The controversial Devils Lake outlet operated for only 10 days before it was shut by pollution concerns, it was learned yesterday.

The Manitoba government was elated to hear high sulphate levels forced North Dakota to turn off the taps, possibly until next year.

North Dakota reported yesterday the outlet that opened Aug. 15 was closed because sulphate concentrations on the Sheyenne River upstream of the outlet exceeded the allowable limit.

Unless the Devils Lake area is hit by heavy rains this fall, it is unlikely the outlet will be turned on again before the spring, which Manitoba says gives the province more time to improve the filter protecting Manitoba from the contents of the lake.

"This is certainly a positive development," said Water Stewardship Minister Steve Ashton.

The Devils Lake outlet is designed to drain 50 cubic feet of water per second into the Sheyenne River, which flows east into the Red River. The Red then carries the water north to Lake Winnipeg.

Manitoba has long feared Devils Lake contains organisms that are foreign and possibly harmful to Manitoba waters. There have also been fears about excess pollution.

Water from the lake was expected to reach the Manitoba border sometime this week, although provincial officials say it may be hard to discern when that actually happens because the water will be heavily diluted. It isn't expected to reach Lake Winnipeg until at least late next week.

North Dakota state engineer Dale Frink said that 10 days after the outlet began operating, sulphate levels on the Sheyenne River upstream of the outlet exceeded 390 milligrams per litre, forcing the state to close the outlet's gate.

The health permit allowing the Devils Lake outlet to be opened prohibits operation when sulphate levels on the Sheyenne River exceed 300 milligrams per litre of water.

Frink blamed the high concentrations of sulphate on the low water flows on the Sheyenne. He said he believes the sulphate is coming from groundwater runoff.

"In the fall, the flow in the Sheyenne drops off significantly," said Frink. "We think that's the reason the sulphate levels are so high."

Environment Canada spokesman Kevin Cash said the jump in sulphate levels when the Sheyenne River's flows are low was entirely predictable. He said it was also expected that would impact on the outlet's operations.

But Cash said the increase in the sulphate level will not result in a breach of the Boundary Waters Treaty, as it is not a sufficient amount to cause harm to Canadian waterways.

"The volume of the water coming out of Devils Lake is unlikely to result in any violation of the sulphate guidelines by the time it reaches the international boundary," said Cash.

Sulphate is an inorganic substance that occurs naturally in water, and is particularly prevalent in ground water. High levels of sulphate in drinking water usually cause a foul taste and odour and have been linked to gastrointestinal problems such as severe diarrhea.

U.S. federal regulations require drinking water to contain no more than 250 milligrams of sulphate per litre of water.

Dwight Williamson, director of water science and management for Manitoba Water Stewardship, said the high levels of sulphate on the Sheyenne are not expected to pose any problems in Manitoba.

Williamson said the International Joint Commission, which oversees boundary water issues between the U.S. and Canada, set a limit of 250 mg of sulphate per litre of water on any body of water as it crosses into either country.

Williamson said once the Sheyenne hits the Red River, the sulphate will be diluted in the higher flows in the Red. He added it has been a very rare occurrence to see the sulphate level on the Red River at Emerson exceed the 250 mg limit.

"Once the Sheyenne mixes with the Red River, the levels (of sulphate) will go down," he said. "Even at 300 mg it is unlikely to exceed the IJC limit at the border."

Williamson said sulphate would only affect aquatic species at extremely high levels.

Frink noted the outlet itself did not cause the increased level on the Sheyenne, but because it would increase sulphate levels slightly, it can't operate when the river is already over its limit.

Manitoba will test the water on this side of the border, but the results won't be relevant until Manitoba can tell whether the Devils Lake water has arrived in our neck of the woods, officials have said.

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