State environmental officials are requiring three Long Island laundromats to test for an unregulated man-made chemical that is a possible carcinogen and has been found in trace amounts throughout most of the area’s drinking water supply.

Earlier this month, the Department of Environmental Conservation approved discharge permits for laundromats in St. James, Brentwood and Lake Ronkonkoma and required that the businesses test for 1,4-dioxane weekly for one month.

DEC’s regional director Carrie Meek Gallagher said 1,4-dioxane is an emerging water quality threat on Long Island and requiring the laundromats to test for the chemical “will add to important data sets to help determine potential sources of this contamination and inform future response actions.”

The chemical is used as a solvent in manufacturing operations but it is also believed to be in about 46 percent of cleaning and personal care products including detergents and soaps.

Results of an Environmental Protection Agency survey of drinking water supplies released in August found the chemical to be present at a 1-in-a-million cancer risk level in 7 percent of samples tested nationwide. On Long Island, 1,4-dioxane was found at the same cancer risk level or higher in 71 percent of water districts tested, Newsday reported last month.

The Citizens Campaign for the Environment requested the laundromats test for the chemical when their wastewater discharge permits were up for renewal, said Adrienne Esposito, executive director of the Farmingdale not-for-profit advocacy group.

“There are numerous laundry detergents that have high quantities of 1,4-dioxane and we are very concerned about laundromats being a point source of contamination,” she said. “The DEC’s action is an indication of the seriousness of the issue.”

The EPA has no set drinking water standard for 1,4-dioxane, meaning it is considered unregulated. But New York has a level of 50 parts per billion for any unregulated organic chemical, which includes 1,4-dioxane.

advertisement | advertise on newsday

There is no long-term permitted method in New York to remove the chemical but the state has approved a pilot treatment system that will launch in April at a Suffolk County Water Authority well site.

DEC said it is collecting data to see if new water quality standards or guidance is required and the laundromat information will be factored into any decision.

Manufacturing is not the only culprit, so additional testing for operators that are using products that could contain 1,4-dioxane is wise, said Paul Ponturo, senior water resources engineer for the Melville consulting and engineering firm H2M Water.

“It’s a focused source of what might be a potential contributor,” he said. “It makes sense to look at specific industries.”

The three laundromats — Dragon Laundromat Inc. in St. James, Wuw Laundromat in Brentwood and Ronkonkoma Laundromat in Lake Ronkonkoma — will have to pay for the tests and report the results to the DEC. A fourth facility may be added soon but that location was not immediately available.

An owner of one of the laundromats, who asked he not be named, said his new permit already required him to install a costly filtration system — one that won’t treat the 1,4-dioxane. “Why are we targeted?” the owner said. “Why not go after the manufacturers? Let the soap companies take the poison out.”