NY / Mamaroneck
NY · Tap water records
Mamaroneck tap water, in plain English
Here is what the EPA's own data shows about tap water in Mamaroneck. According to EPA SDWIS data retrieved June 2026, Mamaroneck is served by 1 active community water system, together reported to serve about 59,629 people.
As of June 2026, EPA records show 10 violations across the community water system(s) serving Mamaroneck, going back to the earliest EPA record. 5 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.
What the EPA has on record, by system
Westchester Joint Water Works
59,629 served · surface water · PWSID NY5903435 - Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between January 2019 and July 2019. The EPA record lists a level of 0.068 MG/L; the limit (MCL) is 0.06 MG/L. All have since returned to compliance, per EPA records.
- Health-based Long Term 2 Enhanced Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in May 2015. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in June 1993. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2020. EPA records do not show all of these as returned to compliance.
- 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 October 2007 and January 2009. 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 June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.