Hopkinton is working on short-term and long-term solutions to address the issue with the town’s water supply following tests that showed higher-than-allowed levels of contaminants, Department of Public Works Director John Westerling told the Select Board at its Tuesday meeting.

Westerling explained that on Nov. 9 the town received notice of noncompliance from the state, as three months of tests showed Hopkinton’s water tested at over 20 parts per trillion for PFAs (per- and polyfluoroalkyl substances).

“We are one of 60 communities in the state that are dealing with PFAs above the maximum contaminant level,” he noted.

The town is required to communicate the issue to residents, which the town will do via social media and an insert in the Hopkinton Independent.

Temporary solutions being discussed include offering a credit to certain higher-risk customers, setting up a water distribution kiosk, and installing a temporary filtration system at Well 6, which is the source of the problem.

“All of these have pros and cons associated with them,” Westerling said. “All of these have costs associated with them. So we are evaluating those options, and we will present the best option to the community.”

Added Westerling: “Our long-term corrective actions include either constructing a permanent filtration system or an indirect interconnection to the MWRA [Massachusetts Water Resources Authority] water supply through the town of Southborough.”

There are eight wells in Hopkinton, and Well 6 is the town’s highest-producing source, Westerling explained, noting that the town could not meet its water needs without that well.

Westerling said individuals who are pregnant or nursing, have an infant below the age of 1, or have been diagnosed with a compromised immune system should not drink the water or cook foods that absorb water (like vegetables or pasta).

“But if you are not in any of those categories, you may feel free to drink the water at your will,” he said. “According to the Department of Environmental Protection [DEP], there’s no threat, no risk to folks either drinking with it, cooking with it, showering with it, brushing your teeth with it or anything.”

Select Board Member Brendan Tedstone credited Westerling for his transparency and efforts to remedy the problem quickly. He also noted that the measured amounts of PFAs do not violate federal standards.

“It should be known that yes, we’re at 28.4 [parts per trillion], which is higher than what the state allowable is, but the federal maximum allowable is 70-plus,” he said. “So it’s not like we’re in Flint, Michigan, drinking their water.”

Three months of tests shows the levels of PFAs rising slightly.

“We saw the numbers go from 20 to 24 to 28,” Westerling said. “And that’s not a dramatic increase, but it is an increase. So our ability to provide water out of Well No. 6 that meets the MCL [state law], we’re just not there. Unless we put a temporary filtration system on that Well No. 6, we’re not going to be able to reach water levels below the maximum contaminant level. … One of the interim solutions that we were looking at was the installation of a rental filtration system you could put on the well, and we thought that was a wonderful idea. But it’s a $170,000 initial installation, and it’s $200,000 a year worth of rental fees and filter media. So that’s part of the analysis that we’ll be doing is the cost-benefit analysis of what all of our options are.”

Westerling said it’s not possible to tell specific homeowners if their water is cleaner than others, and boiling the water only makes the situation worse. Additionally, in-home filters won’t solve the problem, no matter what claims are on the box.

“Bear in mind the DEP is telling us that you can’t filter out PFAs with any home domestic systems,” he said.