Chamberlain Tackles ‘Millions’ of Zebra Mussels Near Water Filtration Plant Intake

South Dakota’s Game, Fish and Parks department first discovered zebra mussels in the water near the Cedar Shore Resort in Oacoma. The migratory patterns and natural flow of the Missouri River led some zebra mussels to settle across the river near the intake lines of the Chamberlain Water Supply Plant.

Mike Lauritsen, City of Chamberlain Administrator, said that while the mussels have yet to make their way through the pipes, they need to be removed before that becomes a possibility.

“They can end up in there,” Lauritsen said. “They will eventually colonize and eventually move up the tube, restricting our water flow.”

The city approved a $ 98,400 contract with Central Divers, a commercial diving service based in Pierre, to remove the mussels.

Although the price seems high, the investment is necessary to avoid further expenses. If the mussels clog the interior of the pipeline, Lauritsen said a process called pigging might be needed to remove the mussels.

Pipe pigging involves inserting a device, called a pig, into a pipe and using pressure to force it through, scraping the interior side walls and carrying the molds out of the pipe.

Lauritsen couldn’t give a price estimate because it varies widely, but said scraping would significantly increase the cost of cleaning.

In addition to the divers who clean the water intakes, the contract specifies that the water will be treated with copper sulphate, a substance that the United States Environmental Protection Agency has called dangerous to humans. and pets.

Despite this, the state and federal governments have an Approval Process for Acceptable Use, with which the City of Chamberlain fully cooperates.

“We had to go through a process with the Corps of Engineers and the Department of Agriculture and Natural Resources to get permits,” Lauritsen said. “It’s less than a part per million that we put in there.”

A study published by the National Institute of Health found that levels of copper sulphate of 100 to 300 parts per million in drinking water produce no adverse effects.

South Dakota Aquatic Invasive Species Coordinator Tanner Davis said copper sulfate is a substance commonly used in water filtration systems when zebra mussels are present.

Although Lauritsen said Central Divers is known for its quality work, Davis said the problem is still present in other parts of the Missouri River and across the state.

“Zebra mussels produce 30,000 to 40,000 eggs per clutch, and they can lay eggs several times a year,” Davis said. “When they develop (from eggs) into veligers, they float freely – their only movement is downstream.”

The only way mussels can move upstream is by attaching themselves to boats that do not remove them before changing water bodies.

“We should be clear about water transport with the larval state of zebra mussels,” Davis said. “People can still have the option of transporting adult mussels in any situation where there is open water.

That’s why, said Davis, the Game, Fish and Parks department is so adamant about draining and cleaning a boat every time it’s taken out of the water.

“Again, we really insist on: cleaning, draining and drying,” Davis said. “It will be up to the public to prevent the spread from spreading.”

Lauritsen added that it only takes one or two zebra mussels to start a breeding population.

“You see the signs on our boat ramps. Make sure you don’t spill them, ”Lauritsen said. “This is one of the most important things that we are trying to push on our athletes in the region.”

Zebra mussels sleep in water temperatures below 54 degrees, but can still be transported dormant.