NY / Armonk
NY · Tap water records
Armonk tap water, in plain English
Here is what the EPA's own data shows about tap water in Armonk. According to EPA SDWIS data retrieved June 2026, Armonk is served by 5 active community water systems, together reported to serve about 5,182 people.
As of June 2026, EPA records show 76 violations across the community water system(s) serving Armonk, going back to the earliest EPA record. 45 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
North Castle Water District #1
2,500 served · surface water · PWSID NY5903445 - Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in October 2022. EPA records do not show all of these as returned to compliance.
- 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 January 2020. 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 January 2016. All have since returned to compliance, per EPA records.
North Castle Water District #4
1,225 served · groundwater · PWSID NY5922909 - Health-based PERFLUOROCTANOIC ACID (PFOA): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 14 times between January 2022 and October 2025. The EPA record lists a level of 11.6 NG/L; the limit (MCL) is 10 NG/L. EPA records do not show all of these as returned to compliance.
- Health-based PERFLUOROCTANE SULFONIC ACID (PFOS): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between April 2025 and October 2025. The EPA record lists a level of 0.0000101 MG/L; the limit (MCL) is 0.00001 MG/L. EPA records do not show all of these as returned to compliance.
- Health-based Manganese: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between January 2017 and October 2020. The EPA record lists a level of 0.4 MG/L; the limit (MCL) is 0.3 MG/L. All have since returned to compliance, per EPA records.
- Monitoring Manganese: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2018 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Iron: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between April 2021 and January 2025. EPA records do not show all of these as returned to compliance.
- Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between January 2017 and January 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 once in January 2015. All have since returned to compliance, per EPA records.
North Castle Water District #2
1,200 served · groundwater · PWSID NY5903446 - Health-based PERFLUOROCTANE SULFONIC ACID (PFOS): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between January 2022 and October 2025. The EPA record lists a level of 13.2 NG/L; the limit (MCL) is 10 NG/L. EPA records do not show all of these as returned to compliance.
- Health-based PERFLUOROCTANOIC ACID (PFOA): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 21 times between January 2022 and October 2025. The EPA record lists a level of 18.3 NG/L; the limit (MCL) is 10 NG/L. EPA records do not show all of these as returned to compliance.
- Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in October 2022. EPA records do not show all of these as returned to compliance.
- 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 January 2020. All have since returned to compliance, per EPA records.
North Castle Water District #5
225 served · groundwater · PWSID NY5903492 - Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2019 and July 2020. All have since returned to compliance, per EPA records.
Saint Nersess Armenian Seminary
32 served · groundwater · PWSID NY5930011 - Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2019. 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 in January 2019. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. All have since returned to compliance, per EPA records.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in 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 June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.