Key Takeaways
- The primary contaminants in Bethpage’s Navy-Grumman groundwater plume are trichloroethylene (TCE) and other chlorinated solvents; 1,4-dioxane is also treated.
- According to the New York State Department of Environmental Conservation (DEC), the plume extends roughly 4 miles south toward the Southern State Parkway and has impacted public supply wells.
- Public water systems in New York must meet a limit of 1 part per billion (ppb) for 1,4-dioxane, which the state set in 2020.
- Activated carbon removes 1,4-dioxane poorly, so utilities treat it with advanced oxidation.
What Is 1,4-Dioxane?
1,4-Dioxane is a synthetic chemical, and it is one of the contaminants being treated in the groundwater plume beneath Bethpage. The EPA’s risk evaluation of 1,4-dioxane notes that it can form as a byproduct of manufacturing processes used for many consumer products, and that it can be present as a contaminant in products such as dish soaps and laundry detergents.
What makes it difficult to address at the municipal level is that activated carbon, a widely used treatment method, removes it poorly. Utilities use advanced oxidation processes (AOP) to treat it instead.
The Bethpage Plume: What the State Has Documented
The Navy-Grumman groundwater plume comes from the former Northrop Grumman Bethpage Facility and the Naval Weapons Industrial Reserve Plant. According to DEC, its primary contaminant is trichloroethylene (TCE) along with other chlorinated solvents, and 1,4-dioxane is also being treated.
The plume extends roughly 4 miles south, toward the Southern State Parkway, and has impacted public supply wells. The site was added to New York’s State Inactive Hazardous Waste Disposal Site registry (the state Superfund program) in 1983. It is a state site, not an EPA National Priorities List site.
For the state’s own account of the plume and the cleanup, see DEC’s 2019 Amended Record of Decision and its February 2023 community update.
Long Island’s Groundwater and Your Public Water Supplier
In Nassau County, public water suppliers rely on the EPA-designated Long Island Sole Source Aquifer as a source of drinking water (DEC, 2019 Amended Record of Decision), so contamination that enters the ground can reach supply wells.
Public water suppliers must meet drinking water limits. In 2020, New York set a maximum contaminant level (MCL) of 1 ppb for 1,4-dioxane, the first state to set one, along with limits of 10 parts per trillion for PFOA and PFOS. Public water systems in New York must monitor for 1,4-dioxane, PFOA, and PFOS on a regular schedule (NYSDOH). Your supplier’s annual water quality report lists the regulated contaminants found in its water.
These limits apply to public water systems, not private wells. If your home is on a private well, you are responsible for testing your own water (EPA).
Other Things That Can Affect Your Tap Water
Beyond 1,4-dioxane, lead can enter drinking water when lead pipes and plumbing materials containing lead corrode (EPA).
Questions about your Bethpage home’s water? Request a free in-home water test.
The pHountain Approach: Test First, Then Configure
Measuring PFAS and 1,4-dioxane at the levels regulators use (parts per trillion and parts per billion) requires analysis by a certified laboratory; a free in-home water test is a starting point for understanding your water and your options.
The pHountain Filtration System is a whole-home (point-of-entry) system with a cartridge-free media design intended to reduce common impurities in tap water. It is installed at the main water entry point of your home, so every faucet, showerhead, and appliance receives filtered water. It is professionally installed and backed by a 10-year guarantee.
A whole-home system is configured around what testing finds. For any specific contaminant, ask for independent certification data (for example NSF/ANSI listings) for the exact system you are considering.
Frequently Asked Questions
Does a whole-house filter remove 1,4-dioxane?
Not every filter does. Activated carbon removes 1,4-dioxane poorly, which is why public water utilities treat it with advanced oxidation. Before relying on any home system for 1,4-dioxane, ask for independent certification data for that exact model.
How do I know if 1,4-dioxane is in my home’s water?
If you are on public water, start with your supplier’s annual water quality report; New York public water systems must monitor for 1,4-dioxane. Measuring 1,4-dioxane at the 1 ppb level New York regulates requires analysis by a certified laboratory. If you are on a private well, testing is your responsibility.
Is Bethpage tap water safe to drink?
Public water suppliers must meet federal and state drinking water limits, including New York’s 1 ppb limit for 1,4-dioxane. Your supplier’s annual water quality report lists the regulated contaminants found in its water. Private wells are not covered by these limits, so testing a private well is the owner’s responsibility.
Do you offer free water testing?
Yes. A free in-home water test is available with no obligation.
Want to understand your home’s water and your options? Request a free in-home water test or call (631) 991-3995.
Sources
- NYSDEC — Amended Record of Decision, Navy-Grumman Bethpage site (2019)
- NYSDEC — Navy-Grumman Bethpage Community Update (February 2023)
- NY State Department of Health — Public Water Systems and Drinking Water Standards for PFAS and Other Emerging Contaminants
- U.S. EPA — Final Risk Evaluation for 1,4-Dioxane
- U.S. EPA — Consumer Confidence Reports (annual water quality reports)
- U.S. EPA — Private Drinking Water Wells
- U.S. EPA — Lead
- U.S. EPA — Contaminant Candidate List
