WARREN – An agreement reached between two environmental groups, 22 private citizens and the Warren Sanitary District will end a federal lawsuit, a state license appeal and improve the quality of effluent discharges into the St. George River by the sewer plant.

The settlement agreement, signed by the Natural Resources Council of Maine, Georges River Tidewater Association, 22 residents and the sanitary district stipulates that changes be made to the district’s discharge license issued by the state Department of Environmental Protection.

The changes to the license would restrict the amount of effluent that can be released into the river during the summer months, require significant expansion of a lagoon for storing effluent and alter the limits on certain effluent test results.

The amended license should be ready for approval by the end of January.The pact also requires the sanitary district to pay fees for lawyers and experts hired by the environmental groups and residents in the amount of $200,000.

“I think the settlement agreement is the right thing to do for the river,” Jon Eaton, GRTA advocacy coordinator, said Wednesday.

“We’re glad to bring this to closure and to get onto the business of running a sanitary district,” Ed LaFlamme, executive director of the sanitary district, said Wednesday. “We hope that our ratepayers are not affected by this. We will continue to run the sanitary district in the most efficient manner possible.”

As far as the costs associated with the settlement agreement, LaFlamme said those expenses would be “shared between the Department of Corrections and Warren Sanitary District.”

In March, NRCM, GRTA and 22 residents filed a lawsuit in federal court claiming that the sanitary district was in violation of the Clean Water Act.

Two months later, the groups, as well as the town of Thomaston, filed appeals with DEP, objecting to the state’s issuance of a license to the sanitary district. Thomaston also has an appeal pending on the site location permit for the prison project.

The long battle also involved testing of the water quality in the St. George River by DEP, which produced a modeling of those results. The model indicated that the sanitary district could increase the amount of discharge into the river to accommodate the flow from a prison expansion in Warren.

According to Eaton, the groups still contend that the state model is flawed and they will continue efforts to get the model corrected, so that the wastewater license is compatible with DEP’s model. The agreement allows the environmental groups to pursue those corrections, he said.

Before a new license was issued by DEP in April, the sanitary district was licensed to release up to 151,000 gallons of treated effluent per day.

It was only discharging about 60,000 gallons daily because the original prison construction was cut back from 500 beds to 100 beds. The latest expansion, due to be completed by Nov. 1, will add 866 beds.

In April, DEP increased Warren’s license to 234,000 gallons daily between Oct. 1 and May 31, but restricted discharge to 100,000 gallons per day from June 1 to Sept. 30.

The terms of the settlement agreement call for up to 79,500 gallons to be discharged daily during the summer months and 244,200 gallons per day during winter. Those flows would maintain a yearly average flow of 190,000 gallons per day, LaFlamme explained.

The changes will require the sanitary district to enlarge one of its four lagoons from a 900,000 gallon tank to an estimated 15 million gallon capacity, LaFlamme said, noting that the larger storage tank is still being engineered and will eventually go out to bid.

The agreement also permits Warren to use a different method of testing its effluent – through a carbonaceous biological oxygen demand measure rather than biological oxygen demand. LaFlamme said that the CBOD testing of effluent provides more accurate results and is the method the district had requested for a long time.

According to Eaton, the CBOD and total suspended solids limits have also been made stricter. The agreed-upon CBOD limits are ones that the sanitary district requested five years ago, LaFlamme said.

The parties established several “best management practices” in the agreement. One of those practices will include the sanitary district installing two baffles and a pumping system in one of the lagoons, which would reduce the nitrification process.

“That was the key issue for us,” Eaton said, explaining that nitrogen stimulates algae growth.

The sanitary district is prohibited from making any changes in its license in the future without conducting an alternatives analysis, Eaton said.

All sides have agreed to support the changes to the Warren license when it goes before DEP, Brownie Carson, NRCM executive director, said Wednesday.

What effect the pact has on Thomaston’s appeal is unknown.

On Wednesday, Thomaston Town Manager Valmore Blastow Jr., said that he had not seen the agreement.

“Clearly, we’ll have to look at it,” he said, adding, “It may well address all our concerns.”

Nick Bennett, an NRCM scientist, and Carson said that the settlement agreement and, in particular, the payment of legal and expert fees, will go a long way in making it clear that polluters cannot flagrantly ignore their actions and that citizens can go to law firms and obtain pro bono help.

Verrill and Dana attorneys of Portland, which represented the environmental groups, had taken the case without expecting payment, they noted. However, had the case gone to trial in federal court and they won, NRCM and GRTA could have sought payment of legal fees.

“It’s a real good precedent for citizens to help fight polluters,” Bennett said.

In crediting the 22 local residents who signed on as plaintiffs, Carson said, “That was a very courageous thing for them to do.”