State officials have renewed efforts to prod the U.S. Environmental Protection Agency into regulating a possible carcinogen found in trace amounts in Long Island’s water supply, after its previous entreaty was met with a noncommittal response.

The state health and environmental conservation commissioners sent a letter Wednesday to new EPA Administrator Scott Pruitt, pressing him to set a “clear, enforceable” drinking water standard for 1,4-dioxane, repeating calls Gov. Andrew M. Cuomo made in a similar letter to Pruitt’s predecessor Feb. 11.

The EPA could not immediately be reached for comment Friday.

But in a Feb. 17 response to Cuomo’s letter, acting EPA Administrator Lisa McCabe said the agency was committed to protecting public health. She said the agency has issued voluntary health advisories and thresholds for short- and long-term exposure for 1,4-dioxane, has put the chemical on a list for possible regulation, and is studying health risks associated with its commercial use.

McCabe, who was replaced after the U.S. Senate confirmed Pruitt Feb. 17, stopped short of agreeing to additional action, and acknowledged the state’s interest in regulating the chemical — a man-made manufacturing solvent that is also widely used in consumer products like detergent and shampoo.

“The EPA appreciates that New York may choose to take action to address 1,4-dioxane contamination while the agency evaluates whether to establish a national primary drinking water regulation,” she wrote.

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McCabe’s letter said 1,4-dioxane was included in an agency list of contaminants that were candidates for regulation, and that the EPA had to decide whether or not to set a standard or seek more data about five of the chemicals or contaminants by January 2021.

The list includes 96 other chemicals and 12 microbial contaminants, and it’s unclear if 1,4-dioxane will be among the five.

In their letter, state Health Commissioner Howard Zucker and Environmental Conservation Commissioner Basil Seggos called that timeline into question. “There are no statutory constraints that preclude EPA from acting faster,” the two wrote.

The request to EPA to regulate 1,4-dioxane was one of a number of actions state officials and politicians have taken since the agency released the results of a nationwide survey of drinking water supplies in August. Every five years all large water suppliers serving more than 10,000 people and a sampling of smaller suppliers must sample for up to 30 unregulated contaminants.

The results showed that 71 percent of water suppliers tested on Long Island had concentrations of 1,4-dioxane that pose a 1-in-a-million cancer risk after prolonged exposure. Nationwide, 7 percent of water suppliers detected similar cancer risk concentrations.

Barring federal action, the state said it would start work to set its own standard — but officials said they believed the issue affected more than just New Yorkers.

“Ensuring access to clean drinking water is an issue of national importance that demands decisive federal leadership,” Cuomo said in a statement Friday to Newsday. “The EPA should prioritize the regulation of 1,4-dioxane and offer consistent, equitable guidance to communities across the country.”

A provision in Cuomo’s proposed budget calls for all water suppliers — regardless of size — to test for emerging contaminants. Funding could be made available in hardship cases.

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State legislators also submitted two bills in January to regulate 1,4-dioxane and create a Drinking Water Quality Institute. And earlier this month, Sen. Elaine Phillips (R-Flower Hill) filed a bill that requires all small water suppliers to test for 1,4-dioxane. It also calls on the state to fund the testing.

“It’s a contaminant that needs to be addressed,” Phillips said. “All water districts should have the opportunity and funding to do this.”