MA / Holliston
MA · Tap water records
Holliston tap water, in plain English
Here is what the EPA's own data shows about tap water in Holliston. According to EPA SDWIS data retrieved June 2026, Holliston is served by 1 active community water system, together reported to serve about 15,713 people.
As of June 2026, EPA records show 231 violations across the community water system(s) serving Holliston, going back to the earliest EPA record. 12 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
Holliston Water Department
15,713 served · groundwater · PWSID MA2136000 - Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between January 2017 and April 2017. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between January 2017 and April 2017. 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: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 9 times between July 2011 and October 2024. 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 7 times between January 2023 and April 2023. All have since returned to compliance, per EPA records.
- Monitoring CARBON, TOTAL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between January 2023 and April 2023. 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 in January 2023. All have since returned to compliance, per EPA records.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. 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 5 times in October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in April 2017. 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 July 2009 and July 2013. 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.