Maryland Wastewater Treatment Plant Floods

July 17, 2019

Plant needs more capacity after severe weather flows sewage into nearby creeks

The city of Frederick, Md., wastewater treatment plant is seeking greater capacity after rainfall lead to a sewage release. 

The city and surrounding areas were hit with flooding the week of July 8, 2019, and the flow then went to more than 30 million gal in an hour, according to The Frederick News-Post. The wastewater plant started to overflow around 8 a.m. July 8, “dumping storm water into surrounding creeks,” said Stona Cosner, the city’s superintendent of wastewater treatment, to The Frederick News-Post. The plant currently treats 8 million gal of sewage and storm water. 

The untreated storm water flowed into a creek feeding the Monocacy River. According to The Frederick News-Post, if the system had more capacity in its equalization basin, the overflow may not have happened.

“Sometimes a few more hours is all you need,” Cosner told the The Frederick News-Post. “That would have been the perfect time because maybe it would have not overflowed; we would have put [that wastewater and storm water] in that tank.”

The plant is fed by sewer main lines by varying sizes. Cosner said engineering studies say 70 million gal of sewage storm runoff can flow through those lines, however the plant can handle approximately 32 million gal for a day or two during severe weather. 

“The basin’s two tanks can hold 750,000 gal of storm water each,” Cosner said. The tanks hold the storm water before they enter the system for treatment. Cosner estimates that the new tank would cost between $3 million and $4 million. 

“It’s kind of a misconception sometimes with the statements that the wastewater plant is overflowing,” Cosner told The Frederick News-Post. “It’s not the plant that’s overflowing; it’s [that] the inlets coming into the plant just can’t handle that much flow into the plant, so it overflows out of the manholes.”