Is Rio Grande City, TX tap water safe?
The short answer
5 of the 6 utilities serving Rio Grande City have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Texas’s records: City of Rio Grande City, City of la Grulla, Rio WSC and 2 more.
City of Rio Grande City, which serves the most people here, has 2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 45.4 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
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 Rio Grande City’s ZIP codes, from EPA’s estimates.
- Open report
City of Rio Grande City
Texas · serves 18,912 people · about 340 in Rio Grande City
2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 45.4 ppb, above EPA’s health benchmark.
2 health-based violations since 2016
- Open report
City of la Grulla
Texas · serves 11,250 people · about 150 in Rio Grande City
1 result above the legal limit, 1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Total trihalomethanes (TTHM) at 100 ppb, above the legal limit.
13 health-based violations since 2016
- Open report
Rio WSC
Texas · serves 6,939 people · about 140 in Rio Grande City
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 43.7 ppb, above EPA’s health benchmark.
1 health-based violation since 2016
- Open report
Union WSC
Texas · serves 5,793 people · about 140 in Rio Grande City
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 43.4 ppb, above EPA’s health benchmark.
1 health-based violation since 2016
- Open report
City of Roma
Texas · serves 19,464 people · under 100 in Rio Grande City
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 38.4 ppb, above EPA’s health benchmark.
5 health-based violations since 2016
- Open report
El Tanque WSC
Texas · serves 3,000 people · under 100 in Rio Grande City
Nothing in its records is above a health goal.
No 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 City of Rio Grande City’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: 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: 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: Arsenic
Water testing near Rio Grande City
The lab Texas certifies closest to Rio Grande City, 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 66 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 TexasZIP codes in Rio Grande City
Which ZIP codes are in Rio Grande City: 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 Rio Grande City
Towns nearby with a page of their own.
What to do next
- Read City of Rio Grande City’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water