4 Nassau water suppliers exceed state limit for 1,4-dioxane

More than three years after New York established an enforceable standard for the chemical 1,4-dioxane in drinking water, four Long Island water suppliers operate wells that do not meet the standard and have been granted “exemptions” by the state health department through August to give them time to comply.

Those four suppliers are the Jericho Water District, the village of Hempstead, the Town of Hempstead and Liberty Water’s Merrick district, which together serve about 150,000 customers. In their required notices to the public, the suppliers assure their customers they are building treatment plants to remove the chemical and, in the meantime, the water is safe to drink. The state Department of Health issues similar assurances. 

But clean water experts say there’s not a lot of scientific evidence about what’s really safe when it comes to ingesting an emerging contaminant like 1,4-dioxane.

“We really have no clue for how many years the public has been exposed to 1,4-dioxane,” said Sarah Meyland, a former professor in the department of environmental technology at the New York Institute of Technology.

And there are no studies yet on the long-term effects of the compound on human health.

“There’s not enough information,” said Vasilis Vasiliou, professor of epidemiology at Yale and director of the Yale Superfund Research Center. “Until we start to get epidemiological data, there’s not much we can say.”

That data could be years away, since toxic effects of chronic exposure can take decades to emerge. In the meantime, water suppliers are scrambling to build treatment systems to meet the standard, even as some experts question whether the limit is truly protective of human health.

Dozens of deferrals, delays

The compound 1,4-dioxane, which the EPA has identified as a probable carcinogen, has been used as an industrial solvent, in spray foam insulation, in adhesives and sealants, and can be found in common household detergents, soaps and cleaning products. It leaches from industrial sites and landfills into the groundwater and has been detected in 70% of Long Island’s public wells.

In 2020, New York became the first state in the country to establish an enforceable standard for 1,4-dioxane in drinking water, with a “maximum contaminant level” of 1 part per billion, or 1 microgram per liter. According to Robert Hayes, director of clean water at Environmental Advocates NY, it's still the only state with an enforceable standard for 1,4-dioxane (rather than an “advisory” level), and there is no federal maximum contaminant level for the compound either.

But it was clear from the start that many water suppliers — especially on Long Island — would be unable to immediately comply. The only known treatment for 1,4-dioxane is an “advanced oxidation process,” which breaks down the chemical with hydrogen peroxide and ultraviolet light. The machinery is expensive and takes time to design, build and test. 

The state therefore offered suppliers temporary “deferrals” to give them time to get advanced oxidation process systems up and running: a two-year pause with the option of another year.

Deferrals were intended for “those who have tests in exceedance of the [maximum contaminant level] and are proceeding to take corrective action,” Kristine Wheeler, director of the bureau of water supply protection at the Department of Health, explained in February 2020. Suppliers had to establish a “compliance timeline with specific milestones”; deferrals could be revoked and fines levied if they failed to meet the deadlines.

Of 28 suppliers that received deferrals, 14 were in Nassau County and seven in Suffolk. Of those 21 Long Island suppliers, 17 received one-year extensions.

Those special arrangements now have expired and cannot be renewed. And while close to 30 wells on Long Island are equipped with treatment systems, according to James Neri, spokesman for the Long Island Water Conference and senior vice president of H2M architects and engineers, about 30 to 40 are still testing above the maximum contaminant level.

Many of those wells are not needed to meet local demand and have been shut down until they are equipped with an advanced oxidation process, said Erin Clary, a spokesperson for the state Department of Health.

Water systems that still don’t meet the standard, and that need to pump from those wells, have been offered one more break: The state Department of Health has given “exemptions” to four suppliers, which now have one final year before they become subject to financial penalties.

Customers of those four suppliers receive periodic notices informing them of “exceedances” but assuring them the water is safe to drink.

'Fully transparent' about problems

Clary wrote in an email the four suppliers “have been fully transparent with the Department" and “have all taken interim steps to minimize 1,4-dioxane in delivered water.”

“These projects are expensive, complex and can take a considerable amount of time to complete,” Clary said.

Nearly every water supplier had to revise initial schedules for completion because of supply chain disruptions during the COVID-19 pandemic. Construction on an advanced oxidation process for seven wells in the Jericho Water District, for example, lagged behind schedule as supplies were delayed, the Jericho district reported last month. 

Liberty originally had planned to finish an advanced oxidation process system at its Seaman's Neck plant next month, but "supply chain disruptions slowed our progress," John Kilpatrick, director of engineering at Liberty Water, wrote in a statement. "Delays in procuring equipment, infrastructure components, pipe, chemical supplies, materials, and treatment system components … have significantly impacted water suppliers with price increases, decreased availability, and longer lead times." 

Kirkpatrick said he expects the treatment plant to be completed by the time the exemption expires next summer. 

“The supply chain has been a bear,” Neri said,

“We know that our customer base is very concerned," Neri added. "Providers are doing their best to be compliant and to alleviate those concerns.”

Costs are another concern, for suppliers and their customers. Although the state has provided grants of more than $275 million for 1,4-dioxane mitigation to Long Island water districts, suppliers still have raised rates to cover costs. The village of Hempstead, for example, raised its rates in August and expects to raise them again next summer. Villagers whose water places them in the highest rate block pay $9.95 per thousand gallons, which the village says “may be the highest on Long Island.”

How much is too much?

Even as new treatment facilities come online, there is still uncertainty about how much 1,4-dioxane is truly safe to ingest.

In December 2018, a panel of experts charged with advising the state on emerging contaminants met to come up with a recommended standard for 1,4-dioxane. But there was significant disagreement on what a safe and practical maximum contaminant level should be.

Two academic members proposed a lower standard (0.35 ppb) than the 1 ppb that was adopted , and two members who were executives at Long Island water suppliers proposed a significantly higher standard (3.5 ppb).

The lower figure was based on the EPA’s estimate of risk for 1,4-dioxane: For every 1 million people consuming 0.35 micrograms per liter of water, every day for 70 years, one will develop cancer as a result. Limits for many contaminants are set at that one-in-a-million level, as Harold Walker, a professor of environmental engineering at Worcester Polytechnic Institute, pointed out during the council’s debate.

Meyland, a member of the council, argued at the meeting that “we should push for the greatest protection for public health and the 0.35 gives us that.”

According to figures presented at the meeting, setting the maximum contaminant level at 0.35 would have required 311 wells or well fields to install an advanced oxidation process, at an estimated cost of $1.11 billion. Adopting the 3.5 ppb that the suppliers preferred would have required treatment at just 24 facilities at a cost of $85.7 million.

Several panel members argued that such high costs would divert funds from other critical infrastructure improvements and would lead to rate increases, which would be hard on low-income residents.

Another participant noted the EPA’s one-in-a-million risk estimate was based on animal studies, not studies of long-term exposure in humans.

Neither the higher proposed standard nor the lower one secured a majority vote, and the 1 ppb recommendation was adopted as a compromise. According to the Center for Hazardous Substance Research, a way to visualize 1 ppb in water is to think of it as about one drop of water in a swimming pool.

Today, three years after New York’s precedent-setting example, some environmentalists believe the state should consider setting a new, lower maximum contaminant level. Hayes, of Environmental Advocates NY, acknowledges a lower standard would require many more advanced oxidation processes on wells that now test below the 1 ppb limit but would be above a limit of 0.35 ppb. But Hayes said the expense would be worth it.

“We recognize there are going to be costs for installing new treatment technologies,” Hayes said. “But what often gets overshadowed in this debate is the cost to human health of inaction, and that usually vastly outweighs the upfront costs to get these chemicals out of the water.”