Here is what the EPA's own data shows about tap water in Nassau. According to EPA SDWIS data retrieved October 2026, Nassau is served by 4 active community water systems, together reported to serve about 1,353 people.
As of October 2026, EPA records show 23 violations across the community water system(s) serving Nassau, going back to the earliest EPA record. 1 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Hansons Mobile Home Park- Kinderhook
50 served · groundwater · PWSID NY1006323
Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2016 and January 2021. All have since returned to compliance, per EPA records.
Kinderhook Lake Mobile Home Park
38 served · groundwater · PWSID NY1006324
Health-based Stage 1 Disinfectants and Disinfection Byproducts Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 2008. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. All have since returned to compliance, per EPA records.
Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring CYANIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2016. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 1999. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 1995. EPA records do not show all of these as returned to compliance.
Sleepy Hollow Mhp
15 served · groundwater · PWSID NY1010860
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between October 2011 and January 2017. All have since returned to compliance, per EPA records.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.