Here is what the EPA's own data shows about tap water in Mission. According to EPA SDWIS data retrieved October 2026, Mission is served by 4 active community water systems, together reported to serve about 207,836 people.
As of October 2026, EPA records show 60 violations across the community water system(s) serving Mission, going back to the earliest EPA record. 4 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.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 2 times between October 2020 and July 2023. 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 December 2013. All have since returned to compliance, per EPA records.
Sharyland Wsc
68,562 served · surface water · PWSID TX1080033
Health-based Chlorite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 2019. The EPA record lists a level of 1.4 MG/L; the limit (MCL) is 1 MG/L. All have since returned to compliance, per EPA records.
Monitoring Chlorite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2018. 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 December 2013. All have since returned to compliance, per EPA records.
Agua Sud
53,796 served · surface water · PWSID TX1080022
Health-based Chlorite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in March 2023. The EPA record lists a level of 1.3 MG/L; the limit (MCL) is 1 MG/L. 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 2 times between July 2015 and October 2015. The EPA record lists a level of 0.09 MG/L; the limit (MCL) is 0.08 MG/L. 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 between December 2013 and October 2025. EPA records do not show all of these as returned to compliance.
Hidalgo County Mud 1
8,420 served · surface water · PWSID TX1080088
Monitoring Interim Enhanced Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between June 2016 and March 2024. All have since returned to compliance, per EPA records.
Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between February 2024 and March 2024. 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 between December 2014 and December 2017. 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 6 times in April 2016. 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 August 2008 and August 2011. 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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.