Investment pays off: Exeter recognized for wastewater treatment excellence
EXETER — The $53 million the town spent on its new wastewater treatment plant has paid off.
The federal Environmental Protection Agency honored the plant and its operators with the 2021 Regional Wastewater Plant Operation and Maintenance Excellence award for its work in reducing the flow of nitrogen into the ecosystem.
The award covers the EPA Region 1 area which includes all of the states in New England. Exeter was one of two recipients, with the other being the Stonington Sanitary District in Maine.
“They have been doing an excellent job of meeting low nitrogen limits and have made a major change in the water quality in the Squamscott River and Great Bay downstream,” said Public Works Director Jennifer Perry.
In 2009, the state’s Department of Environmental Services declared that nitrogen was going to be a contaminant of concern in Great Bay Estuary, which encompasses parts of Strafford and Rockingham counties and is home to a variety of marine life. The state's declaration required the town to do a better job at wastewater treatment.
Perry said high levels of nitrogen are harmful for any saltwater habitat because they promote algae growth which cuts down the amount of oxygen conducive to plants and fish.
“Eelgrass will not usually react well to excessive nitrogen because there’s too much macroalgae that grows on it and blocks out the eelgrass,” said Perry. “Great Bay really is an incredible eelgrass habitat for larval fish and shellfish, it’s kind of the nursery for the marine environment.”
The town has made reducing nitrogen levels a priority, Perry said. In 2012, Exeter and Newmarket were the first to receive the National Pollutant Discharge Elimination System permit which spelled out the requirements for reducing pollutants.
According to Perry, at that time, Exeter's plant was releasing the highest level of nitrogen among plants in the whole region.
Before the new plant was opened in 2019, the old plant, built in 1964, treated wastewater by aerating it in a number of lagoons. Wastewater that came into the plant was filtered, chemically treated, disinfected, dechlorinated and then released.
The aeration system didn't help with nitrogen removal in wintertime because the cold water slows down the chemical process, Perry said.
“In the summertime, sometimes we were able to get lower (nitrogen) levels but had really high (nitrogen) - levels for the majority of the year and we knew we were going to have to do something significantly different," she said.
More: Seacoast cities, towns partner to meet EPA's Great Bay water quality improvement
Tracy Wood, administrator for the state’s DES, nominated Exeter for the award. She recognized the significant efforts the town has put forth, from the proper planning and design, the multiple capital projects that have paved the way for the construction and success of the plant.
“We’re very proud of the accomplishments of the operator and the managers,” said Perry. “The award is well-deserved and we’re very grateful that EPA did give this award to us and that they recognize the improvement that we’ve made. They’re meaningful improvements to the environment.”
This article originally appeared on Portsmouth Herald: Exeter NH recognized for wastewater treatment excellence
