- EPA's UCMR 5 testing looked for 30 contaminants here and found 9.
- Lithium: found in 12 of 12 samples, average 42 µg/L, highest 58.9 µg/L (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFBA (a PFAS): found in 9 of 12 samples, average 6.9 ppt, highest 14.8 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFPeA (a PFAS): found in 9 of 12 samples, average 4.6 ppt, highest 11.7 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFHxA (a PFAS): found in 9 of 12 samples, average 4.5 ppt, highest 11.2 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFOS (a PFAS): found in 3 of 12 samples, average 1.3 ppt, highest 5.6 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFHxS (a PFAS): found in 2 of 12 samples, average 0.60 ppt, highest 4.5 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFBS (a PFAS): found in 2 of 12 samples, average 0.50 ppt, highest 3.5 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFOA (a PFAS): found in 1 of 12 samples, average 0.50 ppt, highest 5.4 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- PFHpA (a PFAS): found in 1 of 12 samples, average 0.30 ppt, highest 4 ppt (EPA UCMR 5 testing, Jul 2024–Apr 2026)
- Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2023–Dec 31, 2025). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
Public EPA test results
Can you drink Rio Hondo tap water? What EPA records show
EPA TX0310096 · serves Cameron County, TX · about 25,509 people (EPA SDWIS)
This report shows EPA's federal records for this water system: UCMR 5 testing, lead testing and violations. It isn't a test of the water at your tap, and it has no Water Score.
Public EPA test results
East Rio Hondo WSC (EPA TX0310096)
EPA data as of October 14, 2026. For Rio Hondo's main utility, East Rio Hondo WSC: We found no health-based violations in EPA's records for this system (TX0310096) since July 1, 2021, as of October 14, 2026. EPA's UCMR 5 testing looked for 30 contaminants here and found 9. This is public data, not a test of your tap.
What EPA records show for East Rio Hondo WSC, as of October 14, 2026
We found no health-based violations in EPA's records for this system (TX0310096) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for East Rio Hondo WSC (SDWIS). Data as of October 14, 2026.
Lead, 90th percentile: 0 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2023–Dec 31, 2025). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
EPA's UCMR 5 testing looked for 30 contaminants here and found 9.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does East Rio Hondo WSC use chloramine?
We didn't find chloramine in East Rio Hondo WSC's EPA treatment records. That's not a complete list; your utility's annual water quality report says which disinfectant it uses.