Over the past two years, 154 million gallons of rain and runoff water has seeped into the Oakland sewer system, costing ratepayers $243,000 to send the clean water unnecessarily through the sewage treatment plant in Waterville.

Sewer Department Superintendent Boyd Snowden reported to the Town Council this week on his latest calculations on the cost of treating “clean” water that enters the sewer system, sometimes by accident and sometimes because rain and runoff drains are directed to the sewers.

Snowden said the department will begin inspections next month of sump pumps in basements around town to make sure that they don’t pump clean rainwater into the sewer system. He’s also proposing that the town buy flow meters, at a cost of about $17,000, to nail down exactly where the excess water is entering the system.

Snowden calculated the amount of clean water sent by Oakland to the Waterville Sewer District for treatment by measuring the amount of water that passed through water meters when entering buildings in town and comparing it with the volume of sewage pumped through checkpoints at First Park on Kennedy Memorial Drive and at Webb Road.

“Clean water can come from anything, such as manholes that the town owns. It can come from leaking sewer mains in the street that the town owns. It can come from leaky lateral pipes that the customers own. It can come from sump pumps, perimeter drains, roof drains and catch basins.”

When the sump pump inspection program begins in March, inspectors will visit homes and commercial businesses to identify units being used to pump water into the sewer system rather than outside into the ground. Snowden would use the portable flow meters in various configurations to isolate areas where clean water is infiltrating the system.

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Last month, the Sewer Department sent out mailers inviting residents to schedule inspections of their homes.

“We really need to nail down where all this is coming from and try to get the low-hanging fruit, where we get the biggest bang for our buck first,” Snowden said.

Water and sewer workers have identified some areas of the town where a lot of clean water is entering the sewer system. Neighborhoods near Oak Street, Oak Hill Drive, Allagash Drive and Water Street are suspected of having the biggest problem.

Snowden conceded, however, that it is impossible to make the system completely free of infiltration through leaky and loose connections.

“We’ll never get 100 percent, but we need to make an effort to close in on that,” Snowden said.

The town will seek a partial grant from the state Department of Environmental Protection to pay part of the cost of the meters.

The sump pump inspections will be time-consuming for the department, Snowden said. He estimated that the town has identified 536 sump pump installations that would need to be inspected.


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