Federal regulators’ advice on water chemicals overtakes Cambridge’s job to filter them out

Sam Corda of the water department at the city’s Walter J. Sullivan Water Purification Facility in a screen grab from a video from the department.

As Cambridge is set to upgrade its water treatment system to halve levels of a group of worrisome and persistent chemicals, federal regulators have warned that much more drastic reductions may be needed. . A June 15 Environmental Protection Agency “health notice” for per- and polyfluoroalkyl substances, known as PFAS, sets limits on minute limits.

PFAS include over 1,000 individual chemicals that resist water, grease, stains and heat. They have been widely used since the 1950s in products as disparate as food wraps, non-stick cookware and fire-fighting foam. They are extremely stable and ubiquitous in the environment, found in soil, bodies of water, fish and other animals. As for humans, depending on exposure, the chemicals have been linked to health effects, including certain cancers, immune system dysfunction, high cholesterol, developmental problems in children and reproductive difficulties. such as reduced fertility.

Most people in the United States have some amount of PFAS in their blood. According to a study by Minnesota health officials in the mid-2000s after improvements in water treatment, reducing levels in a community’s drinking water can reduce blood levels in long-term residents. duration.

In 2016, federal regulators issued a health advisory recommending a maximum level of 70 parts per trillion in drinking water for the combined total of two of the most common chemicals. In response, the Massachusetts Department of Environmental Protection in 2020 set a much lower limit of 20 parts per trillion for the combined total of these two chemicals plus four others under the PFAS umbrella. The state has recommended that “sensitive populations” such as pregnant and breastfeeding women, infants and people with compromised immunity avoid drinking water with concentrations above the limit.

Those numbers are tiny – 1 part per trillion is equivalent to one drop in 20 Olympic-sized swimming pools, according to the Cambridge Water Department. And Cambridge has been at the state limit since 2019, except last September when the total of six PFASs slightly exceeded it, measuring 20.7 parts per trillion.

Still, the Ministry of Water has been working since 2019 to find a way to lower the level of PFAS. As well as measuring concentrations in Cambridge’s drinking water since August 2019, a year later the department began testing three types of materials used in filters for their ability to reduce the presence of the chemicals.

Officials made a choice and asked for offers in March of this year; a company responded. In May, the city was awaiting contract signatures and planned to begin work in June to replace filter media in the 20-year-old filters at the treatment plant, according to a presentation to the water board. Once completed, expected in December, the upgrade will at least halve PFAS levels, according to the presentation.

That may not be enough. The new health advisory from federal regulators in June was based on new findings published after the scientific studies that supported the 2016 advice, the agency said. It now suggests virtually zero limits for two of the key PFAS chemicals measured by Cambridge and regulated by the state: 0.0004 parts per trillion for one chemical and 0.02 parts per trillion for the other. In March, levels of these chemicals in Cambridge water were 1.9 parts per trillion and 8 parts per trillion, respectively, well over 100 times higher than the federal advisory.

Sam Corda, chief executive of the water department, said the department is moving forward with the project. He said the EPA is not expected to issue a regulatory limit for chemicals until the end of 2023, and that’s after a lengthy comment process. Corda hinted it could easily be longer, saying the federal agency’s schedule is “aggressive.”

Corda also pointed out that from now on labs cannot even measure levels as low as the health advisory. Meanwhile, the state limit of 20 parts per trillion for six PFAS chemicals is maintained. The state is reviewing the federal advisory, the Environmental Protection Department said.

Asked about the cost of the filter project, Corda did not answer. The water board was notified in May that the city had allocated funds from the federal Covid-19 relief fund for the project, according to meeting minutes.

Councilman Quinton Zondervan pushed city officials to switch to water from the Massachusetts Water Resources Authority, in part because of problems with chemicals. He reiterated his opinion on June 28, saying: “We should not return to our own water supply until PFAS contamination has been eliminated, through a combination of source identification and remediation. ad hoc, and filtering.”

But it’s not clear that the authority’s water doesn’t have PFAS or would meet the federal advisory levels. The agency tested the six state-regulated substances in August 2019, January 2021 and April 2021 and was exempt from testing for the rest of 2021 due to their low levels, the authority says on its website. No results were reported for this year.

The authority found “trace” amounts of the two chemicals cited by the EPA, saying the amounts were “too low to quantify.” A spokesperson did not immediately respond when asked if the authority had a lab capable of identifying levels as low as the microscopic limits suggested by federal regulators.

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