The City of Moscow is currently researching possible solutions to cool its sewage in order to meet the requirements of the Clean Water Act of 1972, enforced by the Environmental Protection Agency.
Andrew Deskins | Argonaut
Steam rises from the Wastewater Treatment Plant in Moscow Monday night. The sewage in Moscow is approximately half a degree Celsius too hot to comply with Washington standards for the Environmental Protection Agency requirements.
The city must cool the sewage before releasing it into a creek that flows into Washington where the regulations now require the sewage to be cooler than Idaho standards.
Les MacDonald, director of Public Works for the City of Moscow, said there are four promising options to fix the problem.
Each option has its strengths and its weaknesses, he said, and it will take more research to figure out which option will be put into effect.
One of the four options include an evaporative cooling pond to cool the sewage by letting it sit in a controlled space. MacDonald said this may not always work to achieve the desired temperature, which is why the second option is a back-up chiller to go with the pond to mechanically cool the water.
The third option would be to divert the sewage to the local wetlands, for a short time, in an attempt to cool the sewage naturally. The final option would be to directly apply the sewage to a piece of land to help plant life grow, which would completely eliminate the need for the sewage to be cooled.
“The next step that we have started is a couple of pilot studies,” MacDonald said. “Through those studies, we will have a better idea of if the options work, how well they work and what size of facilities we would need to build for now and in the future.”
Kyle Steele, environmental compliance coordinator for the City of Moscow, said the main concern with deciding on an option is making sure that it will be reliable enough to comply with the city’s permit from the EPA. He said it is unclear at this point what would need to be done to apply any of the four options. He said regardless of which option the city chooses, the cost is estimated to be anywhere between $6 million and $12 million.
“If approved, it would affect the utility rate payers,” Steele said. “I don’t know what those rate increases would entail, but I assume we would go out for probably a 20-year bond or something like that to pay that back.”
MacDonald said the city is trying to be good stewards of the environment and stay within the requirements of the EPA, while trying to find a cost effective solution for the problem.
Erik Fink can be reached at [email protected]