TREMONT — Recent testing by the Maine Department of Environmental Protection (DEP) has concluded that the town’s storage of salt and its use on winter roads is contaminating wells, possibly leaving the town liable for the damage. Effluent from private septic systems in the area also is contributing to the problem, the report notes.
The town was notified of the issue in a Jan. 18 letter from Matthew Young of the DEP, which included a recent report by Richard Behr, a DEP geologist who has been studying water quality issues in the area surrounding the town’s landfill, which closed in 1996.
Town Manager Dana Reed informed selectmen about Behr’s conclusions at their meeting on Monday.
“[The DEP] recommends that the town take an active role in addressing the problem,” Reed said.
Reed said the town is legally responsible for its use of road salt contaminating wells. Insurance would pay for damage from application of salt on the roads but not for anything caused by the storage building next to the town office.
In response, selectmen voted 5-0 to have Reed investigate possible solutions and report back to the board.
In 2008, the DEP began testing 14 wells in the Harbor Drive and Flat Iron Road neighborhood to see if contaminants were leaching from the landfill. The water from eight wells was found to contain one or more contaminants consistent with that from landfills. But during meetings with town officials, Behr has said he was unsure about the source of elevated levels of salt in some wells and also stated that septic systems in the densely populated neighborhood could be another source of groundwater contamination. His Dec. 1 report discusses both issues.
One theory regarding the elevated levels of salt was that a sand-salt pile the Maine Department of Transportation maintained in the area from 1952 to 1986 had contaminated the wells. Behr concluded otherwise, writing that salt is “extremely water soluble” and that in the 30 years since the operation closed, one would expect to see a significant decrease in levels found in the wells. Instead, levels are increasing.
“Therefore, the salt used for deicing activities remains the most likely source,” Behr wrote.
Behr also reported the results of testing wells in the area for sucralose, an artificial sweetener approved for human consumption in 1998, two years after the landfill closed. The fact that sucralose is widely consumed and passes easily through the digestive system makes it a good indicator of whether septic systems are contributing to groundwater contamination.
Samples taken from two monitoring wells at the landfill showed no trace of sucralose, but it was detected in samples from private wells.
This “supports my previous assertion that individual septic systems contribute to the documented groundwater contamination,” Behr concluded.
During past discussions regarding contaminants from the landfill, the DEP has recommended the town develop a public water system for the area in question. Instead, selectmen, in 2013, began supplying bottled water to the affected properties under the DEP’s landfill closure and remediation program. The town was reimbursed for 90 percent of the cost by the DEP.
In June, the town was notified that the bottled water program would end. Subsequently, the town is in the process of having individual treatment systems designed and installed at these locations.