The Town of Marion will avoid footing a $20 million bill for sewer plant upgrades after reaching an agreement with the U.S. Environmental Protection Agency that will reduce the scope of prescribed improvements.

Officials learned in 2014 that the town's wastewater treatment facility would require extensive upgrades in order to be in compliance with new federal regulations for sewer plants. The upgrades would be required in order for the town to receive its operating permit for the plant, which needs to be renewed every five years.

Town Administrator Paul Dawson told the Board of Selectmen on Tuesday that the town had reached an agreement that would allow it to obtain its permit while completing fewer of the upgrades previously required by the Environmental Protection Agency.

The permit is required for all facilities that discharge water into the environment. The Environmental Protection Agency had initially required that the town add linings to all three of its sewer lagoons to reduce the amount of nitrogen that seeps into the ground, and add modifications that would decrease the amount of phosphorus produced by the plant.

Officials estimated that the upgrades would cost more than $20 million, which would lead to a drastic increase in sewer fees. Bills would have likely increased from an average of $997 per year in 2015 to nearly $2,700.

Experiencing sticker shock, officials filed a petition to review the requirements with the Environmental Protection Agency's appeals board. The town received a stay on the new permit while the mediation process took place.

With the process complete, the town has agreed to line one of the three lagoons and develop a plan that will allow it to optimize the use of the one lined lagoon to reduce its dependence on the other two.

Additionally, the agency allowed the town to delay implementing the phosphorous-reducing upgrades to the plant, as the town is continuing to determine whether regionalizing sewer service with nearby towns is possible.

“I think at the end of the day we were very successful in our efforts to try to minimize the effect on rate payers while still trying to be good stewards of the environment,” Dawson said.

Officials have been working for years to determine the best way to handle sewer service. With the plant running near capacity, regionalization of service or paying for additional plant upgrades to increase capacity will be necessary.

Even if ultimately the town decides against regionalization, there is still a two-year window for officials to plan for funding the phosphorous-reducing upgrades.

“I think that is a very significant win for the community in terms of being able to better manage some of the costs associate with this permit,” Dawson said.

He also added that he was happy with the way negotiations turned out.

"…I think overall we have a permit that is more manageable and more palatable in terms of cost effectiveness," Dawson said. "It will still accomplish increasing the plant capacity, increase the number of people that are sewered and take care of the environment. But it’s being done on a schedule we can live with and manage.”

Dawson did not have an estimate for what the upgrades will cost, but he said that the price won't be "anywhere close to" the original $20 million estimate.

"I don't have an estimate yet, but we'll be talking about it soon," he said. "We're sort of working to put together a budget plan."

There will be an item on the Town Meeting agenda in May to request the funds for the project.