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Tap water quality report

City of Mercedes

EPA monitoring tested this supplier for 108 contaminants and detected 26. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

108
contaminants tested
26
detected
16,258
people served
35
health-based violations
Texas rankingsLead in TexasPFAS in Texas
Water source
Surface water
Ownership
Local government
Counties served
Hidalgo

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

35
health-based violations
105
violations on file
7
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2024-10-17
TT Health-based Resolved 2024-10-17
TT Health-based Resolved 2024-10-17
TT Health-based Resolved 2024-10-17
MCL Health-based Resolved 2013-07-01 → 2013-09-30
MCL Health-based Resolved 2013-07-01 → 2013-09-30
MCL Health-based Resolved 2013-07-01 → 2013-09-30
MCL Health-based Resolved 2013-07-01 → 2013-09-30
MCL Health-based Resolved 2013-04-01 → 2013-06-30
MCL Health-based Resolved 2013-04-01 → 2013-06-30

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
Pfhxa 0.0033 µg/L 1/4 2024

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
37.2 µg/L
No EPA limit set
 138/138 SYR4 2012–2019
Bromoform
49.8 µg/L
No EPA limit set
 138/138 SYR4 2012–2019
Chloroform
20.8 µg/L
No EPA limit set
 138/138 SYR4 2012–2019
Dibromochloromethane
53 µg/L
No EPA limit set
 138/138 SYR4 2012–2019
TTHM
134.1 µg/L 168%
of the EPA limit, in the worst sample — 80 µg/L
 127/127 SYR4 2012–2019
Dichloroacetic Acid
12.7 µg/L
No EPA limit set
 125/127 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
48.7 µg/L 81%
of the EPA limit 60 µg/L
 125/127 SYR4 2012–2019
Trichloroacetic Acid
9.7 µg/L
No EPA limit set
 125/127 SYR4 2012–2019
Dibromoacetic Acid
20.6 µg/L
No EPA limit set
 124/127 SYR4 2012–2019
Copper
3700 µg/L 285%
of the EPA limit, in the worst sample — 1300 µg/L
 59/68 SYR4 2013–2017
Monobromoacetic Acid
19.2 µg/L
No EPA limit set
 36/127 SYR4 2012–2019
Lead
30 µg/L 200%
of the EPA limit, in the worst sample — 15 µg/L
 33/68 SYR4 2013–2017
Nitrate
860 µg/L 8.6%
of the EPA limit 10000 µg/L
 20/20 SYR4 2012–2019
Lead
0.0037 mg/L 25%
of the EPA limit 0.0150 mg/L
 16/16 LCR 2025
Monochloroacetic Acid
15.7 µg/L
No EPA limit set
 10/127 SYR4 2012–2019
Fluoride
1190 µg/L 30%
of the EPA limit 4000 µg/L
 8/8 SYR4 2012–2019
Barium
102 µg/L 5.1%
of the EPA limit 2000 µg/L
 7/7 SYR4 2013–2019
Selenium
5.4 µg/L 11%
of the EPA limit 50 µg/L
 7/7 SYR4 2013–2019
Cyanide
110 µg/L 55%
of the EPA limit 200 µg/L
 5/6 SYR4 2014–2019
Lithium
61.4 µg/L
No EPA limit set
 4/4 UCMR-5 2023
Arsenic
4.3 µg/L 43%
of the EPA limit 10 µg/L
 3/7 SYR4 2013–2019
Atrazine
0.1400 µg/L 4.7%
of the EPA limit 3 µg/L
 1/8 SYR4 2012–2019
Carbon Tetrachloride
1.9 µg/L 38%
of the EPA limit 5 µg/L
 1/11 SYR4 2012–2019
Combined Radium (-226 And -228)
1.5 pCi/L 30%
of the EPA limit 5 pCi/L
 1/1 SYR4 2017
Gross Beta Particle Activity
6.8 pCi/L
No EPA limit set
 1/1 SYR4 2017
82 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAsbestosBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranChlordaneChromiumCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebEthylene DibromideEndrinEthylbenzeneGross Alpha, Excl. Radon And UHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
MONTOYA, SR, OSCAR, D
Phone
956-565-3114

Frequently asked questions about City of Mercedes

Is City of Mercedes tap water safe to drink?

EPA monitoring detected 26 contaminants in City of Mercedes's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in City of Mercedes's water?

EPA monitoring detected Bromodichloromethane, Bromoform, Chloroform, Dibromochloromethane, TTHM, and others. The full list with the level and data source for each is above.

How many people does City of Mercedes serve?

City of Mercedes reports serving 16,258 people in Texas, per its EPA record.

Has City of Mercedes had any water quality violations?

The EPA has 105 violations on file for City of Mercedes, of which 35 are health-based (a contaminant limit or required treatment was breached) and 7 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.