Here is what the EPA's own data shows about tap water in Madison. According to EPA SDWIS data retrieved October 2026, Madison is served by 2 active community water systems, together reported to serve about 61,152 people.
As of October 2026, EPA records show 75 violations across the community water system(s) serving Madison, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.
Monitoring CARBON, TOTAL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between April 2022 and July 2024. All have since returned to compliance, per EPA records.
Monitoring Endrin: 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 BHC-GAMMA: 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 Methoxychlor: 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 Toxaphene: 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 Dalapon: 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 Diquat: 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 Endothall: 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 Glyphosate: 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 Di(2-ethylhexyl) adipate: 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 OXAMYL: 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 Simazine: 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 Di(2-ethylhexyl) phthalate: 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 Picloram: 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 Dinoseb: 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 Hexachlorocyclopentadiene: 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 Carbofuran: 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 Atrazine: 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 LASSO: 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 Heptachlor: 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 Heptachlor epoxide: 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 2,4-D: 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 2,4,5-TP: 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 HEXACHLOROBENZENE: 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 Benzo(a)pyrene: 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 Pentachlorophenol: 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 Total Polychlorinated Biphenyls (PCB): 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 1,2-DIBROMO-3-CHLOROPROPANE: 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 ETHYLENE DIBROMIDE: 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 Chlordane: 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 Turbidity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2019. All have since returned to compliance, per EPA records.
Monitoring Cryptosporidium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2019. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2019. All have since returned to compliance, per EPA records.
Triana Water Works
7,038 served · surface water · PWSID AL0000905
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 17 times between April 2017 and October 2025. 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 17 times between April 2017 and October 2025. 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 3 times between January 1997 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between September 2009 and April 2020. 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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.