The companies accused of contaminating drinking water wells in North Smithfield, R.I., and Millville, Mass., aren’t accepting responsibility for the contamination, but both states are taking steps to reduce the public-health risks while urging the property owners clean up the mess.

North Smithfield has an inordinate number of contaminated sites associated with industrial operations and dumping. A total of some 40 locations in town and in nearby Millville are considered as sources of water contamination. Several highly polluted sites have received the most scrutiny.

The Stamina Mills Superfund site in North Smithfield was a textile mill that used the solvent trichloroethylene (TCE) to clean new fabric. A TCE spill occurred in 1975, the same year the mill closed. By 1987, residences threatened by the spill were connected to a public water system. In 2006, North Smithfield prohibited the use of private wells near the site to prevent any further contamination from the chemical plume. Groundwater treatment is ongoing.

Western Sand & Gravel, on the North Smithfield-Burrillville border, is a former gravel pit and liquid-waste disposal site that was contaminated by septic and chemical dumping into unlined lagoons and pits between 1975 and 1979. About 600 people within a mile radius of the Superfund site depended on groundwater and eight homes were historically found to have contaminated wells. All of these residences are now connected to a permanent water supply.

Due to their distance from the contaminated wells, both Superfund sites aren’t suspected of causing the pollution on Mechanic Street in North Smithfield and into nearby Millville.

The Nike Control Area on the Air National Guard Base on Old Oxford Road in North Smithfield, a site polluted with firefighting foam containing chemicals known as perfluorooctanoic acids (PFOAs), was also ruled out, as was a vehicle and waste-storage site at 254 Old Great Road.

The Rhode Island Department of Environmental Management (DEM) declined to name the likely polluters of the wells in North Smithfield and Millville. DEM spokeswoman Gail Mastrati would only say “we are not sure at this time but are continuing to investigate potential sources.”

The Massachusetts Department of Environmental Protection (DEP) is more certain. Through testing that began in 2005, the agency has identified the likely sources of the contamination as sites in North Smithfield. Philips Electronics at 51 Industrial Drive and the Polytop Corp. at 110 Graham Drive are suspected because of the direction of the groundwater flow, the location of the pollution, and the high concentrations of the pollutants present in a deep bedrock aquifer, according to DEP.

Philips Electronics conducted metals plating and branding at the 35-acre parcel between 1977 and 1990. Polytop was a plastic dispenser manufacturer.

DEP found the companies liable and ordered them to clean their properties by containing or removing TCE, the solvent perchloroethylene (PCE), and the refrigerant Freon 113. The companies must also conduct testing at private and public water supplies within 1,000 feet of the properties on Providence Street in Millville.

Philips and Polytop, whose site is now owned by the real-estate company Taurus, dispute the findings. Taurus noted that the Polytop site doesn’t show signs of Freon 113 and is more than a mile from the contaminated sites.

“The groundwater on the Polytop Site does not share this ‘fingerprint’ composition,” according to a Jan. 25, 2019 letter from Taurus’ attorney.

The groundwater elevation and flow data, according to an engineer’s report filed by Taurus, don’t support DEP’s conclusion that groundwater flows in the northerly direction from the North Smithfield property toward wells in Millville.

Philips Electronics noted the dissimilar concentration of pollutants between the wells, and has contended that the 1.5-mile distance between its property and the polluted sites is too far for the pollutants to travel considering the low groundwater flow. An engineer’s report commissioned by the company noted higher concentrations of TCE, PCE, and Freon 113 at four Superfund sites that are closer to the contaminated wells. The 2018 report noted 40 other sites in the vicinity of the wells with the same pollutants that deserve further scrutiny as possible sources of the contamination.

DEP, however, has tested and ruled out suspected sites near the contaminated wells, including a 5-acre Superfund site at 254 Old Great Road in North Smithfield that was formerly owned by the Campanella and Cardi Construction Co. and the East Providence Concrete and Asphalt Co.

In 2004, DEM discovered that three wells on Mechanic Street in North Smithfield contained excessive levels of PCE and TCE. Low levels of Freon 113 and other industrial solvents were also detected. DEM began providing bottled water to all residences along Mechanic Street whose TCE levels in their drinking water exceeded the maximum contaminant level.

PCE is a chemical solvent commonly used in dry cleaning and for degreasing metals. TCE is used as a chemical solvent and in refrigerants. It’s also an ingredient in adhesives and stain removers. It has been detected in underground and surface water sources.

In 2015, Mechanic Street residents paid for further testing, which found high levels of TCE and PCE in their drinking water. The Environmental Protection Agency found a contaminated well just across the border from North Smithfield in Millville. In 2016, two more contaminated wells were discovered on Old Great Road.

In Massachusetts, three residences housing nine families living on Providence Street in Millville were impacted by a single plume that contained PCE, TCE, and chlorinated volatile organic compounds (CVOCs). DEP paid to install filtration systems at all three residences, and for a well that serves 19 condominiums.

DEM is providing water and point-of-source carbon-filtration systems to homeowners on Mechanic Street and Old Great Road. In one case, a young family received 30 cases of bottled water and 20 jugs of water a month.

In July, the Rhode Island Infrastructure Bank announced $1.4 million in loans to connect about 30 North Smithfield properties with contaminated wells to the town’s main water line.

“Access to safe, clean and affordable drinking water is fundamentally important for all Rhode Islanders,” said Jeffrey Diehl, executive director of the Infrastructure Bank. “We are proud to support North Smithfield as it expands its water system infrastructure to deliver safe drinking water to its residents.”