MA / Nantucket
MA · Tap water records
Nantucket tap water, in plain English
Here is what the EPA's own data shows about tap water in Nantucket. According to EPA SDWIS data retrieved June 2026, Nantucket is served by 2 active community water systems, together reported to serve about 30,703 people.
As of June 2026, EPA records show 202 violations across the community water system(s) serving Nantucket, 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.
What the EPA has on record, by system
Wannacomet Water Company
27,703 served · groundwater · PWSID MA4197000 - Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 1996. The EPA record for these does not include a measured level. 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 3 times between July 2022 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Sodium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring CYANIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Lead: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2016 and April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring METHYL TERT-BUTYL ETHER: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,3,7,8-TCDD: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1016: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1221: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1232: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1242: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1248: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1254: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring PCB 1262: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1260: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. 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 2008 and October 2009. All have since returned to compliance, per EPA records.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2008. All have since returned to compliance, per EPA records.
Siasconset Water Department
3,000 served · groundwater · PWSID MA4197001 - Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2022 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2025. EPA records do not show all of these as returned to compliance.
- Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,3,7,8-TCDD: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1016: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1221: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1232: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1242: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1248: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1254: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring PCB 1262: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Aroclor 1260: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2024. EPA records do not show all of these as returned to compliance.
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.