Is Los Fresnos, TX tap water safe?
The short answer
5 of the 5 utilities serving Los Fresnos have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Texas’s records: East Rio Hondo WSC, City of Los Fresnos, Olmito WSC and 2 more.
East Rio Hondo WSC, which serves the most people here, has 2 results above EPA’s new limit, which takes effect in 2029, 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: PFOS at 5.6 ppt, above EPA’s new limit, which takes effect in 2029.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Los Fresnos’s ZIP codes, from EPA’s estimates.
- Open report
East Rio Hondo WSC
Texas · serves 25,509 people · about 320 in Los Fresnos
2 results above EPA’s new limit, which takes effect in 2029, 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: PFOS at 5.6 ppt, above EPA’s new limit, which takes effect in 2029.
1 health-based violation since 2016
- Open report
City of Los Fresnos
Texas · serves 6,009 people · about 210 in Los Fresnos
2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 50.5 ppb, above EPA’s health benchmark.
7 health-based violations since 2016
- Open report
Olmito WSC
Texas · serves 8,952 people · about 140 in Los Fresnos
1 result above the legal limit, 1 result above EPA’s new limit, which takes effect in 2029, 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Total trihalomethanes (TTHM) at 76.5 ppb, above the legal limit.
1 health-based violation since 2016
- Open report
City of Laredo
Texas · serves 260,046 people · under 100 in Los Fresnos
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 34.3 ppb, above EPA’s health benchmark.
7 health-based violations since 2016
- Open report
Town of Indian Lake
Texas · serves 888 people · under 100 in Los Fresnos
2 results above the legal limit and 1 result above the health goal. The worst: Total trihalomethanes (TTHM) at 134 ppb, above the legal limit.
9 health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in East Rio Hondo WSC’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: PFOS, PFOA, Arsenic
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: PFOS, PFOA, Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: PFOS, PFOA, Arsenic
Water testing near Los Fresnos
The lab Texas certifies closest to Los Fresnos, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Texas Department of State Health Services South Texas Laboratory
Harlingen, TX · about 57 miles
Certified for bacteria
Texas Well Owner Network, Texas A&M AgriLife Extension: Well Informed screening events, where well owners bring in water samples to be screened for common contaminants, followed by an hour-long session explaining the results. Upcoming events are on the network's calendar. Trainings, Texas Well Owner Network.
All 80 certified labs for TexasWhich ZIP codes are in Los Fresnos: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: TCEQ, drinking water laboratories approved for public water system samples; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Los Fresnos
Other towns in Webb County with a page of their own.
What to do next
- Read East Rio Hondo WSC’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for PFOSRanked by certification and what they cost over five years.The best water filters for PFAS, ranked
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water