Fear and uncertainty are driving some towns to completely eliminate a ubiquitous chemical from their drinking water, even though the EPA says small amounts are safe.
Towns and state governments are asking whether the Environmental Protection Agency’s limit for exposure to poly- and perfluoroalkyl substances, also known as PFAS, is too high. Instead of relying on federal guidance, some towns are trying to remove as much as possible of the chemicals from their drinking water, and states are developing stricter limits.
The EPA determined in 2016 that in drinking water, a person can be safely exposed to perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), two chemicals in the PFAS family, at a concentration of up to 70 parts per trillion during their lifetime.
“The decision by [municipalities] and their customers as to whether to accept this advice is a very local one,” Howard Neukrug, former commissioner and chief executive officer of Philadelphia Water, told Bloomberg Environment.
The extent of the health effects of these chemicals is still unclear, but they may cause high cholesterol, thyroid problems, and testicular and kidney cancers, according to the Centers for Disease Control and Prevention.
Some states also are considering whether the EPA’s 70 parts per trillion exposure level is too high and setting their own limits below that.
Horsham, Pa., found PFAS in every one of its 14 wells after the EPA asked water utilities to start testing for the chemicals in 2013.
“Maybe 70 [parts per trillion] is protective enough, but we haven’t been able to get a definitive answer to that question,” Tina O’Rourke, business manager at Horsham Water and Sewer Authority, told Bloomberg Environment. “We felt we had a responsibility to do better.”
Horsham and its neighbors, Warminster and Warrington, border properties owned by the Navy and Air National Guard.
The military has taken responsibility for the area’s PFAS contamination. The chemicals are believed to come from the military’s use of aqueous film-forming foam, which was widely used to put out fires on aircraft and ships. Once the foam is sprayed onto a training ground, airfield, or accident site, it has the potential to seep into soil and groundwater.
Horsham is aiming for “non-detect” concentrations of PFAS in its drinking water supply, an amount low enough that tests cannot find the chemicals.
The EPA’s lifetime limit may be too high to be safe, O’Rourke said, because the township is uncertain how long PFAS has been in its drinking water or how long its residents have been exposed.
“Despite the best levels of scientific understanding, some communities don’t trust the results of health exposure studies,” Neukrug said.
Anaheim, Calif., found PFOA and PFOS in its water supply, but is following the EPA’s guideline of 70 parts per trillion, “which, for the benefit of everyone, is extremely stringent,” Mike Lyster, spokesman for the city, told Bloomberg Environment.
States’ drinking water limits for PFOS and PFOA vary, though all are under the EPA’s 70 parts per trillion limit. Some are now revising their limits, making them more stringent.
“That’s probably a trend that will continue,” David Flannery, senior global market segment manager at Cabot Corp., told Bloomberg Environment. Cabot, a specialty chemicals and performance materials company, has developed an activated carbon technology to remove PFAS from drinking water.
The Association of State Drinking Water Administrators wrote to the EPA and Centers for Disease Control and Prevention Jan. 12 about inconsistent PFAS limits.
The EPA has not yet developed a single, enforceable limit for PFAS in drinking water. According to the agency, it’s collecting data and conducting analyses required under the Safe Drinking Water Act to evaluate PFOA and PFOS. Drinking water limits often are used as cleanup targets at Superfund and other waste sites the EPA oversees.
“We’re concerned that several sets of differing risk numbers will be communicated from each agency, which will cause confusion, delay, or worse, no action at all,” the association wrote.
According to Alan Roberson, a spokesman for the Association of State Drinking Water Administrators, they have not received a response from the EPA or CDC.
“There are technologies available now that can treat many of the PFAS compounds down to non-detect,” David Woodward, vice president and PFAS technical leader at Wood Plc, doing business as Amec Foster Wheeler, told Bloomberg Environment.
Developing those technologies also can test their long-term use as more municipalities install permanent remedies for their water supplies, Woodward said.
Calgon Carbon Corp. installed permanent PFAS removal filters on two of Horsham’s contaminated wells.
In addition to installing filtering systems, Horsham is shutting down wells and buying water from other towns, even though the concentration of PFAS in the township’s drinking water falls below EPA limit. By blending drinking water sources, the town estimates that its PFOS and PFOA levels are about 4 parts per trillion.
“There have been a few instances so far where municipalities have been very close to the [EPA’s] health advisory goal and then go ahead and decide to implement the [PFAS removal] technology,” Ralph Franco, director of municipal products for Calgon Carbon, told Bloomberg Environment.
“I would say that’s more of an exception than a rule,” he said.
Like the EPA, Vermont’s limit is based on a combined measure of PFOS and PFOA. But instead of setting it at 70 parts per trillion, the state set a limit at 20 parts per trillion.
Sarah Vose, toxicologist at the Vermont Department of Health, said the state’s limit differs because unlike the EPA, Vermont considered the potential health effects of the chemicals for children under one year old. That’s a standard consideration when Vermont reviews drinking water contaminants, she told Bloomberg Environment.
New Jersey is proposing a maximum limit of 14 parts per trillion for PFOA in drinking water. The state is revising its acceptable level down from 40 parts per trillion, which it set in 2007.
“A large body of relevant health effects information from both human and animal studies has become available since it was developed,” the New Jersey Department of Environmental Protection said in a memo last October.
New Jersey also proposing a maximum limit of 13 parts per trillion for PFOS in drinking water. Like Vermont, the state considered infants who may be exposed to PFOS when drafting its limit, according to the New Jersey Drinking Water Quality Institute.
The differences in state standards “demonstrate the difficulty in calculating health risk goals and determining risk reductions without federal standards, and are creating public confusion about what levels of PFAS are safe in drinking water,” the association wrote.
Pennsylvania is choosing to follow the EPA’s health advisory for drinking water while it considers whether to set a state limit, Neil Shader, spokesman for the Pennsylvania Department of Environmental Protection, told Bloomberg Environment.
Pennsylvania, like the association, is encouraging the EPA to provide more support to states and take the lead on PFAS limits.
—With assistance from Pat Rizzuto and David Schultz.
This is the fourth part of a Bloomberg Environment series looking at the impact of fluorinated chemical contamination on communities and businesses.