New NJ Drinking Water Study Shows Surprising Trend

Levels of cancer-linked "forever chemicals" in New Jersey's public drinking water dropped by as much as 55 percent after the state moved to regulate them, according to a new Rutgers Health study published in the journal “Environment International.”

The study, published in March, analyzed nearly 12,000 water monitoring results from 47 community water systems across the state between 2006 and 2025. Researchers found sharp declines in three per- and polyfluoroalkyl substances — PFOA, PFOS, and PFNA — after New Jersey's Drinking Water Quality Institute formally recommended limits for each chemical.

PFOA levels fell 55 percent following the regulatory recommendation. PFNA dropped 50 percent. The share of water samples testing above safety limits for PFOA fell from 49 percent to 15 percent. For PFNA, exceedances dropped from 24 percent to 1.5 percent.

“We knew that these standards had been put in place, and it’s now been almost 10 years,” lead author Hari Iyer, a cancer epidemiologist at Rutgers Robert Wood Johnson Medical School, said in Rutgers Today. “We wanted to see: was there any impact of these regulations on the actual levels in the water?”

New Jersey was the first state in the country to set an enforceable PFAS drinking water standard, adopting a maximum contaminant level for PFNA in 2018 and adding limits for PFOA and PFOS in 2020.

One of the study's notable findings was that water utilities began acting before regulations took full legal effect. Once the state's advisory body recommended limits, systems started shutting down contaminated wells and installing granular activated carbon filtration systems, before compliance monitoring was formally required.

"They said, 'We know what's going to happen when you put regulations in place. The levels are going to drop. It's not rocket science,'" Iyer said of government colleagues who initially questioned the need for the study. "But I think people want to know if these policies are working."

PFAS — a family of thousands of synthetic chemicals used in nonstick cookware, waterproof clothing, food packaging, and firefighting foam — have been detected in the blood of an estimated 99% of Americans. Even low concentrations in tap water can produce blood levels more than 100 times the drinking water concentration, according to the study.

The chemicals are linked to immune system disruption, liver and kidney damage, low birthweight, and multiple cancers. In 2024, the International Agency for Research on Cancer classified PFOA as a known human carcinogen.

New Jersey has been contending with PFAS contamination since at least 2005, when the chemical was detected in tap water near the DuPont Chambers Works plant in Salem County at levels up to 64 nanograms per liter.

A prior analysis by the Environmental Working Group found that New Jersey's 563 public water utilities — serving more than 8.8 million people — have 131 known contaminants, including PFOA and PFOS.

The study comes as federal PFAS regulation is in flux. The Trump administration has delayed enforcement of federal drinking water limits for PFOA and PFOS until 2031, and the EPA has signaled it may rescind limits on four additional PFAS chemicals. The EPA also withdrew a proposed rule that would have capped the amount of PFAS manufacturers can discharge into waterways.

Melanie Benesh, vice president of government affairs at the Environmental Working Group, called the federal standards "the most significant action on drinking water in a generation for some of the worst chemicals in drinking water."

"It means thousands of people are not going to get sick or die from serious, chronic diseases," Benesh told Patch. "It shouldn't be reversed. Lives and health are at stake."

The study has limitations. The 47 water systems analyzed were generally larger and had longer monitoring histories than typical systems statewide. About 11 percent of New Jersey residents rely on private wells not covered by the state's drinking water regulations. Researchers also found that levels of some unregulated PFAS increased during the study period; the authors noted this could reflect changes in chemical use patterns but did not draw conclusions.

Iyer said his team is now working to connect water quality data to health outcomes, using cancer registry records to model how PFAS exposure may be associated with patient survival and other outcomes.

A separate Rutgers Cancer Institute study, called REPEL, is recruiting men with prostate cancer to measure PFAS levels in both blood and tap water.

Home filtration systems can remove many PFAS before water reaches the tap, Iyer told NJ Spotlight News, adding that the New Jersey State Government has resources available for residents who want to learn more.

"There are a lot of things in the world that can harm us," Iyer said. "We want to make sure we're focusing our regulations and our energy on the things that matter most and setting limits that actually improve human health."

(The study, "Impact of regulatory actions to establish maximum contaminant levels on per- and polyfluoroalkyl substances in New Jersey public water systems," was published in Environment International. Lead author Hari Iyer is an assistant professor and cancer epidemiologist at Rutgers RWJ Medical School and a member of the Cancer Prevention and Control Program at Rutgers Cancer Institute.)

Have a correction or a news tip? Email sarah.salvadore@patch.com