Published September 28 2013
Moorhead Public Service takes water treatment to higher groundMOORHEAD – The new Red River Pumping Station here is designed to withstand the type of flooding that historically threatened the city’s water supply, but it also wields a metallic shield aimed at warding off a potential future menace: zebra mussels.
While the invasive species has yet to appear at Fargo-Moorhead’s water treatment plants, Moorhead Public Service decided to spend extra for a zinc-alloy screen to repel zebra mussels that otherwise could clog the water intake.
Still, the flood-resistant features of the new pumping plant are by far the biggest improvement over its predecessor, installed in 1959.
“There’ll be no sandbagging, no diking or anything around it. It’ll be an island, basically,” said Bill Schwandt, general manager of the publicly owned utility.
The pumping station cost about $2.8 million to build and is responsible for supplying Moorhead with about 85 percent of its drinking water.
After the 1997 flood fight, a dike was built around the old pumping station, protecting it to a river level of 39 feet. The unstable riverbank didn’t allow MPS to build higher than that, so sandbags were used to raise the dike an additional 4 or 5 feet during flood fights in recent years, said Kris Knutson, water division manager.
The old station’s water pumps sat in the basement at a river elevation of about 23 feet, and the electrical systems were at 35 feet, Knutson said. In the new station, all essential equipment has been raised to a river elevation of 45 feet, which will keep it high and dry even at a 500-year flood.
Knutson was hesitant to call the station flood-proof, joking, “I don’t make bets like that.
“I would say it’s flood-resistant,” he said.
The pumping station began operating in March, before the spring flooding season that turned out to be less severe than predicted.
“It worked flawlessly through that period,” Knutson said.
Among the other upgrades in the new station:
- The water intake, a half-cylinder about 14 feet long and 3 feet tall with tiny pores, is now in the middle of the river instead of near the river bank.
“What’s nice about that is that if there’s a storm and a lot of the storm water runs off into the river, we don’t get a big slug of salty, dirty water after a rainstorm, and then there’s less chance of it getting plugged by debris that’s in the river,” Schwandt said.
- Three new “variable frequency drive” pumps will boost energy efficiency by allowing MPS staff to control water flow by slowing down or speeding up the pumps’ motors, as opposed to the old constant-speed motors that required opening and closing valves to regulate flow.
- A new “air burst” system will allow staff to unclog the screen by sending compressed air or water out through the intake. Knutson said the old screen had to be physically pulled out of the river and set on the riverbank to be cleaned – an impossible task during times of flooding.
The majority of funding came from a pre-disaster mitigation grant from the Federal Emergency Management Agency, which covered 75 percent of much of the cost.
Moorhead Public Service’s share ended up being about $1 million, which was higher than a 25 percent share because of additional features not covered by the grant, including a special PVC liner for the 60-year-old concrete intake pipe and the zebra mussel-repellant screen.
Fargo’s water intakes on the Red River are about 25 years old and don’t have a similar screen to repel zebra mussels, but the city will likely look at installing them if mussels someday are detected here, said Mark Peterson, superintendent of Fargo’s Water Treatment Plant.
“We’re just kind of in that monitoring phase right now,” he said.
In celebration of Public Power Week, Moorhead Public Service will hold a ribbon-cutting ceremony to dedicate the new pumping station at 6 p.m. Oct. 8 at 1409 River Drive S. An open house with tours of the station will follow.
Readers can reach Forum reporter Mike Nowatzki at (701) 241-5528