BUCKSPORT, Maine — Town officials are beginning to plan for what is expected to be the lengthy and expensive process of upgrading the town’s wastewater plant from a primary to a secondary treatment facility.
The town is negotiating an administrative agreement with the state Department of Environmental Protection that will require the town to complete the upgrades within the next decade. Depending on the capacity of the new plant, the project is expected to cost between $5 million and $10 million.
This is not an unexpected development. Town Manager Roger Raymond said Thursday that the federal Environmental Protection Agency notified the town in 2007 that it would not renew the waiver that had allowed Bucksport to operate its plant at primary levels. That waiver, approved in the early 1980s when the town was planning to build its existing treatment plant, allowed small communities like Bucksport to treat at primary levels because their flow was small enough that the effluent from the plants would not negatively affect the receiving waters.
According to Raymond, an EPA review of the Clean Water Act determined that, because the Bucksport plant, and several others in the state, discharged into the Penobscot River and not ocean waters, it should not have been given the waiver in the first place.
Ironically, the town had pressed for the state and federal agencies to allow it to build a plant to secondary treatment levels back in the 1980s. At that time, Raymond said, the agencies determined that the flows at the planned treatment plant were not high enough to justify secondary treatment and that they would not fund the additional treatment capacity.
Primary and secondary treatments differ mainly in the amount of solids that are removed from municipal waste water before the effluent is discharged into a body of water. The levels of solids are measured by percentages of biological oxygen demand and total suspended solids in the effluent. Those percentages are substantially higher for secondary treatment facilities than for primary ones.
Raymond said the existing plant regularly exceeds the levels stipulated in its license, but has not reached the higher secondary treatment standards.
In 2007, Raymond said, the town asked for a delay in the process since the existing treatment plant still had several more years left on its 30-year life expectancy. The timing of the secondary treatment project now will coincide with the end of that 30-year period, he said. The existing plant began operating in 1988.
“This allows us to get close to the expected life of the treatment plant, when we would probably have to do extensive upgrades there,” Raymond said.
Although Raymond said the town may be able to use some elements from the existing facility, the project will require construction of new treatment plant.
“The systems are totally different,” he said.
Although it is still years away, the new plant will be built on the existing 6-acre site and will be able to use existing sewer lines into the plant and the discharge pipe into the river.
Raymond stressed that this will be a lengthy process. Once the agreement with the DEP is final, the town will hire a consultant and an engineer to plan and design a plant. The town then will have to develop a funding package. Although the town has put aside reserve funds during the past several years, those funds likely will cover only the consulting and design costs, Raymond said.
“We can handle the preliminary and design costs without a problem,” he said. “But when we go to construction, we’re going to need some help.”
The rule for construction costs of secondary treatment plants calls for about $1 million for every 100,000 gallons of flow. In Bucksport, the average flow is about a half-million gallons a day with peak flows as high as 1 million gallons. That translates into costs of $5 million to meet the average flows or $10 million to construct a plant that will handle peak flows.