This is a well pump at the Hicksville Water District's...

This is a well pump at the Hicksville Water District's pump station on Newbridhge Rd. The contaminant 1,4-Dioxane was discovered in the well water. Credit: Newsday / John Paraskevas

State officials reacted with admirable urgency last year to reports of the threat to Long Island’s drinking water posed by the unregulated chemical 1,4-dioxane. But after delays in setting up a council to devise a drinking-water standard for safe levels of the possible carcinogen, and slower-than-anticipated testing of Long Island’s state Superfund sites, it’s important that the state keep its energy and focus.

The council formed last year by Gov. Andrew M. Cuomo will soon set a 1,4-dioxane standard. That’s critical, given that the federal Environmental Protection Agency has no specific guidelines. The state Department of Environmental Conservation said last February it would begin on Long Island a campaign to test all state Superfund sites, but analyzed only 29 of the region’s 154 sites in 2017. DEC officials promise to complete the job this year. That’s essential.

There is no dispute about the severity of the problem. Nearly three-quarters of Long Island’s water suppliers have found 1,4-dioxane, which is present in some consumer-care products and used in solvents. That’s 10 times the national average. More than 40 percent of the region’s Superfund sites that have been tested had alarming levels. If the chronically understaffed DEC needs more resources for testing, the state should find the money. Getting this data soon is critical, with the Suffolk County Water Authority awaiting state Department of Health approval to put into service a treatment system it piloted that has produced promising results.

Knowing where 1,4-dioxane is lurking and what quantities of it pose a threat to human health is crucial. Knowing the nature of the problem is essential before it can be solved. — The editorial board