NY / Mahopac
NY · Tap water records
Mahopac tap water, in plain English
Here is what the EPA's own data shows about tap water in Mahopac. According to EPA SDWIS data retrieved June 2026, Mahopac is served by 18 active community water systems, together reported to serve about 10,190 people.
As of June 2026, EPA records show 128 violations across the community water system(s) serving Mahopac, going back to the earliest EPA record. 76 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
Carmel Wd 2
5,000 served · surface water · PWSID NY3903641 As of June 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.
Carmel Wd 3
1,350 served · groundwater · PWSID NY3903642 - Health-based Chloride: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 8 times between April 2023 and July 2023. The EPA record lists a level of 253 MG/L; the limit (MCL) is 250 MG/L. EPA records do not show all of these as returned to compliance.
Carmel Wd 8
1,000 served · surface water · PWSID NY3903644 - Health-based Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 1993. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 July 1994 and October 1998. EPA records do not show all of these as returned to compliance.
Carmel Wd 4
450 served · groundwater · PWSID NY3905675 - Health-based Chloride: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 20 times between July 2019 and November 2023. The EPA record lists a level of 460 MG/L; the limit (MCL) is 250 MG/L. 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 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 October 1998. EPA records do not show all of these as returned to compliance.
Carmel Wd 9
400 served · groundwater · PWSID NY3903648 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 October 2002. EPA records do not show all of these as returned to compliance.
Carmel Wd 14
400 served · groundwater · PWSID NY3905700 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
Carmel Wd 7
300 served · groundwater · PWSID NY3905697 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
Carmel Wd 12
300 served · groundwater · PWSID NY3921719 - 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 1998 and October 2006. EPA records do not show all of these as returned to compliance.
Yorkview Estates W S Inc
200 served · groundwater · PWSID NY3903651 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 1997. EPA records do not show all of these as returned to compliance.
Carmel Wd 6-Shell Valley
200 served · groundwater · PWSID NY3905709 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 July 1994. All have since returned to compliance, per EPA records.
Carmel Wd 5
150 served · groundwater · PWSID NY3905698 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 July 1994. All have since returned to compliance, per EPA records.
Carpenter Trailer Park
100 served · groundwater · PWSID NY3915411 - 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 October 2005. EPA records do not show all of these as returned to compliance.
White Sail Condominium W.S.
85 served · groundwater · PWSID NY3922189 - Health-based Chloride: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 30 times between April 2022 and January 2024. The EPA record lists a level of 336 MG/L; the limit (MCL) is 250 MG/L. 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 1997. EPA records do not show all of these as returned to compliance.
Water Club Condominiums W.S.
75 served · groundwater · PWSID NY3903718 - Health-based Chloride: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between April 2019 and October 2023. The EPA record lists a level of 351 MG/L; the limit (MCL) is 250 MG/L. 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 2 times between June 2003 and January 2005. All have since returned to compliance, per EPA records.
Shore Estates Owners Assoc Inc
60 served · surface water · PWSID NY3903649 As of June 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.
Middlebranch Apts
50 served · groundwater · PWSID NY3903715 - Health-based Chloride: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 9 times between October 2018 and October 2023. The EPA record lists a level of 711 MG/L; the limit (MCL) is 250 MG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in March 2020. 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 March 2020. All have since returned to compliance, per EPA records.
Carmel Wd 6-Tomahawk Creek
50 served · groundwater · PWSID NY3909761 - Monitoring 1,4-Dioxane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANE SULFONIC ACID (PFOS): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring PERFLUOROCTANOIC ACID (PFOA): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. 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 July 1994 and October 1998. EPA records do not show all of these as returned to compliance.
Lake Properties
20 served · groundwater · PWSID NY3902003 - Health-based Iron: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between April 2022 and January 2023. The EPA record lists a level of 0.449 MG/L; the limit (MCL) is 0.3 MG/L. 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 June 2003. 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.