< view all Public Notices


Deferral Issued for 1,4-Dioxane at South Huntington Water District

On behalf of the South Huntington Water District (SHWD or District), H2M architects & engineers (H2M) has prepared this document in accordance with the requirements of the New York State Department of Health (NYSDOH) for public water suppliers who have been granted deferrals from maximum contaminant level (MCL) violations for 1,4-dioxane. The District was granted an MCL deferral for 1,4-dioxane in 2020. The SHWD was granted a deferral because it has been proactive in its efforts to establish and implement an action plan for managing the above-referenced compounds.

Download the SHWD MCL Deferral Quarterly Report Q3 2023


Why are you receiving this notice/information?
You are receiving this notice because testing of our public water system found the chemical 1,4-Dioxane in your drinking water. This is above New York State’s maximum contaminant level (MCL) of 1 part per billion (ppb) for 1,4-Dioxane in public drinking water systems. The MCL is set well below levels known or estimated to cause health effects. Consuming drinking water with 1,4-Dioxane at or somewhat above the MCL does not pose a significant health risk. Your water continues to be acceptable for all uses. The South Huntington Water District is working on a strict timetable to reduce levels below the MCL.

The South Huntington Water District has submitted, and the New York State Department of Health (Department) has issued, a deferral to the South Huntington Water District. When a public water system is issued a deferral, the water system agrees to a schedule for corrective action and compliance with the new MCLs. In exchange, the Department agrees to defer enforcement actions, such as assessing fines, if the water district is meeting the established deadlines. We are required to update the Department and the Suffolk County Department of Health each calendar quarter on the status of our projects. If we do not meet the agreed upon deadlines, the Department can resume enforcement.

What are the health effects of 1,4-Dioxane?
Laboratory studies show that 1,4-Dioxane caused liver cancer in animals exposed at high levels throughout their lifetime. Other types of cancer have also been reported, although less consistently than liver cancer. There is no evidence of 1,4-Dioxane cancer effects in humans. The United States Environmental Protection Agency considers 1,4-Dioxane a likely human carcinogen based upon studies of animals exposed to high levels of this chemical over their entire lifetimes.

At the level of 1,4-Dioxane detected in your water, exposure from drinking water and food preparation is well below 1,4-Dioxane exposures associated with health effects.

What is New York State doing about 1,4-Dioxane in public drinking water?
The New York State Department of Health (NYS DOH) has adopted a drinking water regulation that requires all public water systems to test for 1,4-Dioxane. If found above the MCLs, the water supplier must take steps to lower the level to meet the standard. Exceedances of the MCL signal that steps should be taken by the water system to reduce contaminant levels.

What is being done to remove this contaminant?
During the deferral period, the South Huntington Water District will operate the wells affected by 1,4-Dioxane in a “last-on/first-off” fashion in addition to blending impacted wells with unimpacted wells to minimize 1,4-Dioxane levels. The District will make every effort to operationally minimize the concentration of 1,4-Dioxane in the distribution system at any given time. Additional information will be shared as further testing and progress occurs. This process is similar for any chemical detected in public drinking water that requires mitigation. The compliance timetable will ensure that your drinking water will meet the MCL as rapidly as possible. The deferral is effective until July 31, 2023.

Where can I get more information?
For more information, please contact South Huntington Water District at 631-427-8190  or 75 5th Avenue South, Huntington Station, New York 11746. You can also contact the Suffolk County Department of Health Services at 631-852-5810.

If you have additional questions about these contaminants and your health, talk to your health care provider who is most familiar with your health history and can provide advice and assistance about understanding how drinking water may affect your personal health.

Public Water System ID# NY5103263

view archives >