After $4 million and almost 18 months, Long Island’s second treatment system for 1,4-dioxane went online this week, breaking down and removing the likely carcinogen.
Treated water from the Bethpage Water District well was introduced into service Wednesday at 9:30 a.m. by sending water through residents' taps.
"This is a significant milestone," said Mike Boufis, superintendent of the Bethpage Water District.
The well site, at Lowell Street and Park Lane, is in Long Island's largest plume of pollution from the former Northrop Grumman and Navy-owned operations.
Boufis said this should "reassure our public that Bethpage Water has always been at the forefront" of treatment.
He added: "I’ve been doing this well over 30 years, [and] this is the biggest hurdle as a water industry we’re going to face for quite a while. "
The cost and time it has taken to get it in service also shows the challenge Long Island water districts face to remove 1,4-dioxane, which has been tied primarily to industrial sites where it was used as a solvent stabilizer, but is also found in some household products.
Water districts across Long Island have warned of severe conservation measures and rate hikes when the state starts enforcing a standard for 1,4-dioxane, one of three new contaminants New York State is looking to regulate in drinking water.
The state estimates 89 facilities across Long Island are above the state's proposed 1 part per billion standard for 1,4-dioxane.
Water providers have said more wells are near that standard, and total costs will approach $840 million, and double or triple water costs. The Bethpage Water District was awarded a $1.6 million grant to help pay for the system. Boufis said the district has been in “active negotiations for any plume-related costs and reimbursements associated with 1,4-dioxane” with Northrop Grumman and the Navy.
The first Long Island water treatment system for 1,4-dioxane opened in Central Islip in 2018, operated by the Suffolk County Water Authority.
1,4-dioxane isn't removed by traditional treatment methods, and treatment systems have to be adjusted based on water chemistry and contaminants at other sites.
The treatment process involves mixing hydrogen peroxide with the water, then blasting it with ultraviolet light from dozens of light bulbs to destroy the 1,4-dioxane molecules. The resulting contaminants are then removed by running the water through four containers holding 20,000 pounds of granular-activated carbon.
The process, known as advanced oxidation process, or AOP, has to be changed depending on a site's water chemistry.
In Bethpage, the treatment initially created other chemical byproducts, including acetone, the main ingredient in nail polish remover, Boufis said. That since has been eliminated by changing the amount of hydrogen peroxide that's added.
Boufis said they'll be increasing the testing at the well for quality control. "We’ll be at that site a few times a day, around the clock, making sure everything is fine," he said.
Before treatment, the water has average 1,4-dioxane contamination at 11 times the proposed state standard. The treatment system removes other contaminants, like the solvent trichloroethene, or TCE, which is also present in the well.
The state and county departments of health had to sign off before the system went online.
"It's not one-size fits all when it comes to the AOP system. Each has a different water chemistry, each requires a different engineering system," said Roger Sokol, director of the state's division of environmental health protection.
State officials said costs will vary depending on factors, including whether additional land needs to be purchased and outside engineering costs. Approvals could be sped up as water districts learn from the water chemistry at the Central Islip and Bethpage locations.
State Department of Health spokesman Gary Holmes said 25 water systems are pilot-testing treatment systems. He said the state has adequate staffing to handle the regulatory influx, but is hiring more engineers.
Sokol said, "This is a priority for bureau and department, and we’re going to make sure we’re able to handle it."