How cold could impact bacteria in Potomac after sewage spill

The cold weather could actually be keeping E. coli and other bacteria in the Potomac River from the raw sewage spill alive longer by slowing the natural cleansing process.

“So, those colder temperatures slow bacterial growth; they slow down decomposition,” Storm Team4 meteorologist and science teacher Ryan Miller said. “And that’s what’s happening out here. The pathogens that worked through the sewage water that were in the water and distributed, the water temperature right now is 39 degrees. That’s refrigerator temperature water, and that water will help to slow the growth of the bacteria, prevent the die-off, a massive die-off of the bacteria. So, from that standpoint, the cold water can actually help transport further distances some of the pathogens.”

Another factor that can keep the bacteria from breaking down naturally is the ice.

“We’ve got ice on a lot of the river,” Miller said. “If you look at the main channel, you can see it’s ice covered. That ice is reflecting sunlight. It’s reflecting UV light that can help to sterilize some of the water and the pathogens that are in it.

“Plus, as the water moves downstream, it’s out of sight, out of mind,” he said. “I mean, a lot of sewage treatment or a lot of pollution management is: dilution is the solution. And as it moves down river, yes, it’s getting diluted, but that’s still the risk of these pathogens in the water still exists. I mean, it’s significant.”

There’s also the tides to worry about.

“The low flow of water is also working against us right now,” Miller said. “You need more water to help flush and dilute the pollutants that are in and present in the environment. The water level, I’ve never seen it this low right now.”

A channel filled with water last week is almost empty.

“And right now we’re looking at a lot of rock and a lot of bare area that is not covered in water,” Miller said. “So, it’s that lack of flow that’s going to also have impacts on this.”

Miller hopes local, state and federal agencies will step in and provide testing to ensure the river is safe for human contact and recreation.

“The burden is on our government to, one, prove to us that this water is safe to be around or to consume things that come from it or to use for things like crew or a boat or doing something on the water,” he said.

Most of the raw sewage is no longer going into the river but being diverted into the C&O Canal and funneled back into underground pipes.

The spill is below where drinking water comes from, so that water supply has not been affected.