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Public water system record

City of Mercedes

Serves Mercedes, Hidalgo County, TX · 16,258 people served

Federal records show 1 health-based violation and 7 monitoring/reporting issues for City of Mercedes in the last ten years. The most serious issue in this window was a resolved LEAD AND COPPER RULE REVISIONS violation.

  • TX1080007
  • MERCEDES
  • TX
  • 16,258 served

System profile

Source water Surface water
ZIP 78570
EPA system ID TX1080007

Verify this system on EPA ECHO →

Health-based violations, last 10 years
1
Resolved
1
Unresolved
0
Any acute record
No
Monitoring issues, last 10 years
7

Key facts

  • City of Mercedes draws water from 1 well and 1 surface water intake.
  • Most recent formal enforcement: compliance order with a penalty by Texas, January 2014.
  • Record on file since 2004, with 8 health-based violations before October 19, 2016.
  • Lead pipe inventory: 0 lead and 872 unknown out of 4,314 service lines.

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

Contaminant Rule family Start date Status Acute
LEAD AND COPPER RULE REVISIONS
Treatment technique failure
 350 Oct 17, 2024 Resolved No

Monitoring and reporting issues

Since October 2016

Missed tests or reports, not contaminants found above a limit.

Issue Start date Status
Lead and Copper Rule
Monitoring and reporting
 Dec 30, 2025 Active
Public Notice
OTHER
 May 1, 2025 Resolved
LEAD AND COPPER RULE REVISIONS
RPT
 Oct 17, 2024 Resolved
E. coli
Monitoring and reporting
 May 5, 2020 Resolved
Public Notice
OTHER
 Jul 13, 2013 Active
Public Notice
OTHER
 Apr 15, 2011 Active
Enforcement action in place
Public Notice
OTHER
 Jan 10, 2011 Active
Enforcement action in place

Full record since 2004

EPA's records for City of Mercedes go back to 2004. Before October 19, 2016 they list 8 health-based violations (8 resolved) and 40 monitoring or reporting violations.

Violations that began in Health-based Monitoring and reporting
2000s 2 30
2010 to October 18, 2016 6 10
2020s 1 4

Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began July 2013, Resolved.

Show all 8 health-based violations before October 19, 2016
Contaminant Start date Status
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.086 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
 Jul 1, 2013 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.1 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
 Apr 1, 2013 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.107 mg/L, federal limit 0.08 mg/L (1.3 times the limit)
 Jan 1, 2013 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.082 mg/L, federal limit 0.08 mg/L (at or just above the limit)
 Oct 1, 2012 Resolved
Total Coliform
Contaminant limit exceeded
 Oct 1, 2012 Resolved
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
 Aug 1, 2012 Resolved
Total Coliform
Contaminant limit exceeded
 Jun 1, 2007 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.088 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
 Jul 1, 2004 Resolved

Enforcement actions

Texas regulators took 3 formal enforcement actions against City of Mercedes between 2005 and 2014. The most recent was a compliance order with a penalty in January 2014.

Date By Action Violations covered
Jan 25, 2014 Texas Compliance order with a penalty 4 violations (4 health-based): Total Trihalomethanes (TTHMs)
Jul 19, 2013 Texas Compliance order with a penalty 4 violations (1 health-based): Public Notice, Total Coliform
Dec 15, 2005 Texas Compliance order with a penalty 1 violation (1 health-based): Total Trihalomethanes (TTHMs)

What the violations mean

LEAD AND COPPER RULE REVISIONS

1 incident

The system did not complete a treatment step or action that the LEAD AND COPPER RULE REVISIONS requires (a treatment technique violation).

The utility had to notify customers about this violation.

Where the water comes from

City of Mercedes draws water from 1 well and 1 surface water intake. It also has emergency connections to City of Weslaco and North Alamo WSC. 2 other community water systems buy water from City of Mercedes. 1 other public water system has an emergency connection to City of Mercedes.

Emergency or part-time connections to

Community systems that buy water from it

Annual water quality report

City of Mercedes must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Texas.

Certified drinking water labs by state EPA guidance for private wells