TX / Mercedes
TX · Tap water records
Mercedes tap water, in plain English
Here is what the EPA's own data shows about tap water in Mercedes. According to EPA SDWIS data retrieved June 2026, Mercedes is served by 3 active community water systems, together reported to serve about 17,858 people.
As of June 2026, EPA records show 201 violations across the community water system(s) serving Mercedes, 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
City Of Mercedes
16,258 served · surface water · PWSID TX1080007 - Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. 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 2 times between October 2013 and December 2025. 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 6 times between August 2007 and May 2025. EPA records do not show all of these as returned to compliance.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. 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 3 times between September 2010 and May 2020. All have since returned to compliance, per EPA records.
Llano Grande Lake Park East
1,300 served · surface water · PWSID TX1080034 - Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between March 2019 and October 2022. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between April 2015 and October 2015. The EPA record lists a level of 0.086 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 36 times between December 2013 and September 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 10 times between July 2018 and July 2025. 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 24 times between August 2013 and August 2023. All have since returned to compliance, per EPA records.
- Monitoring Nitrite: 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. EPA records do not show all of these as returned to compliance.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between April 2017 and October 2022. EPA records do not show all of these as returned to compliance.
Llano Grande Lake Park West
300 served · surface water · PWSID TX1080236 - Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between August 2019 and February 2022. The EPA record for these does not include a measured level. 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 52 times between October 2012 and September 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 12 times between January 2004 and July 2025. 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 22 times between February 2016 and March 2025. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between July 2015 and October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 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.