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When heavy rains fall, Plattsmouth sewage runs into river

By ALGIS J. LAUKAITIS / Lincoln Journal Star
Monday, May 12, 2008 - 06:42:17 pm CDT
One of the state’s oldest river towns also has one of the oldest sewer systems.

And when rain falls on Plattsmouth, untreated sewage flows into the Missouri River.

Plattsmouth and Omaha are the only two cities in Nebraska with a combined stormwater and sewer system, said Donna Garden, a permits and compliance supervisor with the Nebraska Department of Environmental Quality.

That’s going to change.

Both cities are under a state and federal mandate to fix their systems. The problem: A heavy rain can send water into the sewer system and overload the wastewater treatment plant.

When that happens, the water  mixture — which contains untreated sewage — must be released into the Missouri River.

In Plattsmouth, Garden said, a 12-by-12-foot outfall gate opens to release the mixture into the  river.

Omaha has about 30 such gates, Garden said. Public Works Department officials in that city  could  not be reached for comment Monday.

“This is a common situation in a lot of older communities in the United States, especially in the eastern part of the country,” Garden said.

It doesn’t take much rain to overload Plattsmouth’s sewage treatment plant — only about 0.14 inches and the gate opens,” she said.

The sewage contains human pathogens, fecal matter and other waste. Discharging untreated  sewage into the river is a violation of federal and state water quality standards.

Garden said there is no evidence the sewage is harming fish or other wildlife in the river.

Plattsmouth’s water/wastewater superintendent Gary Hellwig said the city is in the first phase of finding a solution. It hired HDR  Engineering Inc. to do a study. Omaha also hired the firm.

Plattsmouth has until September 2010 to present a plan to the DEQ, Garden said. If it’s approved, the city will have another five years to implement its plan to correct the problem, which Hellwig said has been going on “forever.”

Plattsmouth officials are looking at two possible alternatives: capturing the sewer/storm water flow in a large basin for treatment and slow discharge; or installing two separate systems, one for sewage and the other for storm water, Hellwig said.

No cost estimates were available. Hellwig said those should come from HDR when the study is completed by the end of the year.

“Certainly it will be a big project,” Hellwig said.

Meanwhile, Plattsmouth is trying to maximize contaminant controls and monitor the problem. The problem doesn’t occur with every rainfall of 0.14 inches or greater, Hellwig said.

“It depends on how fast it comes,” he said.

Reach Algis J. Laukaitis at 402-473-7243 or alaukaitis@journalstar.com.