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Updated 2026-10-15
County water report

Cameron County Water Quality: 4 Cities Ranked by the Records

Cameron County, Texas: 4 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my systemOpen on the mapPrivate wells in Cameron County
Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

LithiumDetected in 4 systems10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest58.9 µg/L
Perfluorooctanesulfonic acid (PFOS)Detected in 3 systems of 4 tested4.0 ng/L federal MCL (2024) · US EPAHighest9.2 ng/L
Perfluorooctanoic acid (PFOA)Detected in 2 systems of 4 tested4.0 ng/L federal MCL (2024) · US EPAHighest5.4 ng/L
Water hardnessDetected in 1 systemAesthetic, no federal health limit · USGSHighest13.7 gpg
Perfluorohexanesulfonic acid (PFHxS)Detected in 3 systems of 4 tested10 ng/L federal MCL (2024) · US EPAHighest5.3 ng/L
Perfluorobutanesulfonic acid (PFBS)Detected in 1 system of 4 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest3.5 ng/L
Perfluorohexanoic acid (PFHxA)Detected in 4 systems400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest11.2 ng/L
Perfluorobutanoic acid (PFBA)Detected in 4 systemsNo federal or state limit; shown for transparencyHighest14.8 ng/L
2 more contaminants detectedShow
Perfluoroheptanoic acid (PFHpA)Detected in 3 systems of 4 testedNo federal or state limit; shown for transparencyHighest4.1 ng/L
Perfluoropentanoic acid (PFPeA)Detected in 4 systemsNo federal or state limit; shown for transparencyHighest11.7 ng/L
22 substances tested, none detected in any systemShow

Tested in these 4 systems: BROWNSVILLE PUBLIC UTILITIES BOARD, CITY OF SAN BENITO, EAST RIO HONDO WSC, HARLINGEN WATER WORKS SYSTEM

  • 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
  • 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
  • 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
  • 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
  • Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
  • Lead (90th percentile)
  • N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
  • N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
  • Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
  • Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
  • Perfluoro-3-methoxypropanoic acid (PFMPA)
  • Perfluoro-4-methoxybutanoic acid (PFMBA)
  • Perfluorodecanoic acid (PFDA)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • Perfluorononanoic acid (PFNA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
4 cities

Cities ranked by the records

Showing 4 of 4 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Cameron County3 of 4 city reports had a PFAS sample above a 2024 EPA limit
  1. Brownsville9.2 ng/L
  2. Rio Hondo5.6 ng/L
  3. San Benito4.8 ng/L
4.0 ng/L federal MCL · PFOS, ng/LPFAS in Texas
Lead

0of 4 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Texas
Hard water

1city reports hardness · Brownsville, 13.7 gpg

Hard on the USGS scale. An aesthetic measure with no federal health limit.

Hard water explained
Who supplies the county

Largest water systems

  1. BrownsvilleBROWNSVILLE PUBLIC UTILITIES BOARD · TX0310001
    201,249 served
  2. HarlingenHARLINGEN WATER WORKS SYSTEM · TX0310002
    85,900 served
  3. Rio HondoEAST RIO HONDO WSC · TX0310096
    25,509 served
  4. San BenitoCITY OF SAN BENITO · TX0310007
    24,250 served
Questions

Frequently asked

How does Cameron County tap water compare across cities?

PurityMap ranks 4 cities in Cameron County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Harlingen's main water system: HARLINGEN WATER WORKS SYSTEM · PWSID TX0310002 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Cameron County cities had a PFAS sample above a 2024 EPA limit?

3 of 4 Cameron County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Brownsville (PFOS 9.2 ng/L), Rio Hondo (PFOS 5.6 ng/L), San Benito (PFOS 4.8 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 4.

Is there lead in Cameron County tap water?

Utilities report lead as a 90th-percentile result from home taps. 0 of 4 Cameron County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Does Cameron County have hard water?

Hardness is published in utility water-quality reports for 1 Cameron County city on record; the hardest is Brownsville at 13.7 grains per gallon. Hardness affects scale and appliances; it is not a health finding.

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