Public Water Systems and Drinking Water Standards for PFAS and Other Emerging Contaminants

Public Water Systems and Drinking Water Standards for PFAS and Other Emerging Contaminants is available in Adobe Portable Document Format (PDF).

New York State and National Drinking Water Regulations

New York State is committed to reducing exposure to chemicals in drinking water and continues to work with the Environmental Protection Agency (EPA) and local health departments to protect public health and help communities comply with drinking water standards. We will work to harmonize the state and federal requirement for all New York State public drinking water systems.

Under EPA’s new federal standards, public water systems must comply with new federal maximum contaminant levels (MCLs) of 4 ppt for PFOA and 4 ppt for PFOS by 2029. EPA has also set MCLs for four additional PFAS not currently regulated in New York State. Until 2029, public water systems must still meet New York State maximum contaminant levels of 10 ppt for PFOA and PFOS.  New York State residents can continue to drink their water unless told otherwise by their public water system, or the local or state health department.  

New York State was one of the first to develop its own health-based enforceable drinking water standards for PFOA and PFOS in 2020. The State continues work in close coordination with local health departments to identify public water supplies with PFOA and PFOS levels above 10 ppt and require them to take action to remove PFAS from these water supplies. The Department of Health has also helped communities remove PFAS from drinking water through infrastructure grant and loan opportunities.  

About PFAS

PFAS-containing products.

Per- and polyfluoroalkyl substances (PFAS) are contaminants used in many products and have been linked to health issues. New York State has been developing drinking water standards, also called maximum contaminant levels (MCLs), to address these contaminants starting with the two most common PFAS: perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Public drinking water with PFOA or PFOS above the MCLs must be treated to reduce the levels below the MCL.

New York’s drinking water standards for emerging contaminants are among the most protective in the country. In 2020, New York State set MCLs of 10 parts per trillion (10 ppt) for PFOA and PFOS, and 1 part per billion (1 ppb) for 1,4-dioxane. New York was the first state to develop an MCL for 1,4-dioxane. New York is working to pass even more drinking water standards and notification levels for up to 23 PFAS.

The New York State Department of Health continues to review the evolving science around health risks associated with drinking water contaminants, closely follow efforts by the U.S. Environmental Protection Agency and other states, and will update or develop additional drinking water standards as needed to protect public health.

About Drinking Water Standards

  • Drinking water standards set maximum contaminant levels (MCLs), that are the highest level of a contaminant allowed in drinking water delivered by public water systems. MCLs are enforceable regulatory limits.
  • All MCLs require public water systems to regularly monitor for contaminants, notify health departments and the public of confirmed exceedances, and work with health departments on a timetable and plan to bring water systems into compliance.
  • The New York State MCLs established in 2020 are set at health protective levels that decrease risks for the wide range of PFAS health effects to the greatest extent that is currently feasible and achievable.  The new federal MCLs will take five years to implement.  The Department is working with our federal and local health department partners and look forward to achieving even greater PFAS reductions as these new MCLs are implemented. 
  • MCLs are different than health advisory levels (HALs) or maximum contaminant level goals (MCLGs) that do not consider feasibility or the ability for water systems to measure the contaminants at low levels.
  • The Safe Drinking Water Act requires EPA to set MCLGs based only on health data and the potential impacts to public. MCLGs are not regulatory levels and are not enforceable. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. The MCLs, which are used for compliance determination, are set at specific concentrations that laboratories nationwide can measure with high certainty.

Public Water System Requirements

  • Public water systems in New York must monitor for more than 100 different contaminants on a regular schedule, including PFOA, PFOS and 1,4-dioxane.
  • Public water systems must report on all PFAS included in the analytical method when they detect any level of PFOA and PFOS. This helps identify additional unregulated PFAS contaminants that may be present.
  • New York’s largest and some smaller public water supplies must also monitor for a select list of emerging drinking water contaminants every five years under EPA’s Unregulated Contaminant Monitoring Rule.
  • As with all MCLs, water systems must notify their local health department of any exceedances. If there is a confirmed MCL exceedance, the public water system will work with their local health department to notify the public and develop a course of action and timetable to reduce levels below the MCL.
  • Some water systems will need to make significant infrastructure upgrades to their water treatment processes and these projects could take several years to complete. Unless there is an exposure that represents an immediate health risk, the water remains acceptable for use while the water system takes actions to reduce levels below the MCL.

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