Mystic plans may require upgrades

Proposed developments could mean more sewage sent to plant in Stonington Borough

Stonington — With more than $100 million in new development proposed in Mystic, town officials have begun work on a plan to increase the capacity of the Mystic sewer treatment plant by pumping sewage to the borough plant.

This would accommodate the new construction, which is expected to generate large amounts of new tax revenue at the same time as state aid to the town continues to drop.

At last week’s Board of Selectmen’s meeting, First Selectman Rob Simmons made the first public mention of the project, which likely will require residents to approve bonding for required upgrades to the existing pipeline, the two plants and the system of pumps at and between them.

Currently, the Mystic plant is nearing the point in its permit that triggers a requirement for developing a plan to ensure that it does not exceed its permitted treatment capacity.

The plant is permitted to treat and discharge a maximum of 800,000 gallons a day of sewage but the state Department of Energy and Environmental Protection requires the town to begin planning how to handle additional capacity once it consistently

“Stonington and Mystic are among the few communities in the state that are still growing. We want to keep it that way.” DOUGLAS NETTELTON, WPCA EXECUTIVE DIRECTOR

reaches 90 percent, or 720,000 gallons — which Water Pollution Control Authority Director Douglas Nettleton said the town has come close to at times in the summer.

If the plant consistently nears or meets the limits in its permit, the WPCA would not be able to approve any new developments connecting to the sewer system. This essentially would create a moratorium on new development.

“This is important because (the capacity limit) could stifle growth. Stonington and Mystic are among the few communities in the state that are still growing. We want to keep it that way,” Nettleton said.

The Planning and Zoning Commission already has approved a three-phase project to turn the 70-acre Perkins Farm property on Jerry Browne Road into a $70 million medical and research campus with apartments and town homes. Seaport Marine in downtown Mystic has unveiled a plan to redevelop its property into a hotel, restaurant, commercial space, apartments, town homes, single-family homes and a public-access boardwalk. In addition, developers have discussed the construction of three new hotels in the so-called Golden Triangle area at Route 27 and Coogan Boulevard.

All those projects would produce large amounts of sewage that would needed to be treated at the Mystic plant.

“We have a lot of development planned for Mystic, so this is not something we want to wait too long to do,” Nettleton said.

He said the study is one DEEP would require the town to do eventually but waiting too long could result in a moratorium on new hookups.

Nettleton said he is developing a request for proposals from consultants to study the various options and costs of such a project. He said that if the town had a plan in place in 18 to 24 months, it would be able to seek bonding approval when the debt payments on the elementary school project begin to drop. It is unknown how much the sewer line project will cost.

“We’d like to be first in line for bonding at that point,” he said.

Nettleton said the existing pipeline between the two plants appears to be in good condition. But updates would be required to pumps in Mystic and along the pipeline, as well as to mechanical, electrical and technical equipment at both plants.

In addition, there would be added odor control measures and steps would be taken to ensure there is a steady level of flow to the borough plant.

Nettleton explained that sewer plants operate most efficiently and without problems when flow levels remain steady and do not fluctuate greatly.

Nettleton said he was sure the town could take steps to prevent odor problems at the borough plant and along the pipeline from the increased flow. The pipeline extends east along Route 1 and down North Water Street into the borough.

The pipeline was built about 25 years ago and at the time sewage was sent from the overburdened Mystic plant to the borough. That process was stopped when upgrades were made to the Mystic plant.