The Environmental Protection Agency is considering what restrictions to place on the town’s wastewater treatment plant, and Selectmen hope alternative, less expensive options will be allowed.

On Tuesday, Town Administrator Paul Dawson said town engineers have completed their review of the agency's National Pollutant Discharge Elimination System permit. Several comments on the draft permit were forwarded to the EPA.

The draft permit, which was released in December, is required for facilities that discharge water into the environment. They identify and limit the amount of pollutants released, such as toxins, nitrogen, copper, aluminum and other materials.

Selectmen learned the new draft permit is so different from the previous one that it's impossible to follow the new regulations without significant upgrades.

If implemented as drafted, the new permit would require millions of dollars worth of improvements at the wastewater plant.

One major change prohibits the use of three sewage lagoons. Installed in the 1970s, the lagoons take up a 20-acre footprint on the site and store excess wastewater when the plant is at capacity.

For the lagoons to meet draft permit requirements they must be lined to prevent wastewater from leaching into the soil, according to the EPA.

Other regulations dramatically reduce the amount of heavy metals and nitrogen allowed in discharged water. Meeting those regulations would require a new filtration system at the plant.

“The details of the final draft permit will dictate the level of work that needs to be done,” Dawson said. “We’re kind of in flux right now.”

He said the engineers from the town-hired firm CDM and Smith are searching for alternative solutions that would allow the plant to meet the agency's requirements while using less costly upgrades.

There is no deadline for the EPA to issue the final permit. Dawson said it could be within the next three weeks or the next three years.

In the meantime, he said the town and CDM and Smith engineers will explore alternative options.