Pennsylvania Storm Highlights Need For Better Stormwater Management

Stormwater management is key at any wastewater treatment facility. But sometimes even the most prepared utility is overwhelmed by a massive weather event.

In Pottstown, PA, a recent storm dropped nearly two inches of rain in just a few hours, flooding basements and roads throughout the area. But it was at the WWTP that the storm’s impact caused the most damage, with an estimated 250,000 gallons of untreated sewage spilling into a drain that ultimately empties into a river used as a drinking water source for several downstream communities, reports The Mercury News.

The spill came from an exposed trough connecting the screening building with the next stage in the treatment process. Some of the untreated sewage spilled into the plant’s aerators, thus ensuring it was at least partially treated. The rest flowed down to the river, reports the Mercury News.

The plant was designed to handle a peak of 15 million gallons of sewage in any given day. During the storm it is estimated that 60 to 65 million gallons pass through the plant.

Two weeks prior to the storm, a massive 30-inch snowfall had taken place. Storm sewers were at capacity before the storm even began. The combination of events made it was nearly impossible for utility workers to prevent an overflow.

“We saw eight sealed manhole covers pop, some that I’ve never seen before,” said Public Works Director Dug Yerger, according the Mercury News. “There was a stream of water going down Hanover Street. I’ve never seen that before.”

Wagner said the plant operators took every step possible to create as much capacity in the treatment plant as possible.

“In fact, I’m amazed we pushed as much through the plant as we did without any damage to the plant,” Wagner said, according to the Mercury News.

The incident highlights improvements that need to be made at the plant in order to avoid repeating events.

Several problems are posed by inflow and infiltration flaws. On the infiltration side, groundwater seeps into sewer lines through cracks in the sewer laterals and main pipes. Then inflow, such as rainwater, gets into the wastewater system instead of the stormwater system, reports the Mercury News.

This is a challenge the Pennsylvania Department of Environmental Protection (DEP) is working with municipalities to address. The DEP has been notified of the incident but has yet to issue a final determination regarding it.

The city of Pottstown has invested $9 million to replace sewer aims over the next five years.