City of Rio Hondo
What EPA’s and Texas’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 2,640 people
- Connections
- 824
- Water source
- Surface water
- Based in
- Rio Hondo, TX
- County
- Cameron
- Owner
- Local government
The ZIP code it serves
The short answer
2 results are above the health goal. The worst: Arsenic, above the health goal. 47 health-based violations since 2016.
What handles itWhat was found
Arsenic, uranium, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, nitrate and chromium (total): Texas’s own results, samples taken from March 6, 2020 to Sept. 9, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the health goal2
Arsenic
Comes from the source
2.8ppb
Highest yearly average, 2020 to 2026
Averaged by year, the highest was 2.8 ppb, in 2026: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.5 ppb, in 2015.
What handles it
- NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
- NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
Uranium
Comes from the source
1.7ppb
Highest yearly average, 2021 to 2024
2024, one sample: 1.2 ppb
Averaged by year, the highest was 1.7 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2024, the latest year on file, its one sample was 1.2 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppb, in 2018.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits4
Total trihalomethanes (TTHM)
Forms or is added in treatment
60.3ppb
Highest yearly average, 2020 to 2026
2026 average: 52 ppb
Averaged by year, the highest was 60.3 ppb, in 2025, below EPA’s legal limit of 80 ppb. Its highest single sample was 79.8 ppb. In 2026, the latest year on file, its six samples averaged 52 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 169 ppb, in 2017, and EPA recorded violations in 2016, 2017 and 2018.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Haloacetic acids (HAA5)
Forms or is added in treatment
27.3ppb
Highest yearly average, 2020 to 2026
2026 average: 17.4 ppb
Averaged by year, the highest was 27.3 ppb, in 2022, below EPA’s legal limit of 60 ppb. Its highest single sample was 40.7 ppb. In 2026, the latest year on file, its six samples averaged 17.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 59.5 ppb, in 2017, and EPA recorded violations in 2017 and 2018.
What handles it
No certification claim covers this compound yet.
Fluoride
Forms or is added in treatment
0.52ppm
Highest yearly average, 2020 to 2026
2026: not found
Averaged by year, the highest was 0.52 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.47 ppm, in 2013.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.31ppm
Highest sample; found in 6 of 11
2026: not found
The highest sample, in 2022, was 0.31 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in any of its three samples. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.21 ppm, in 2014.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Chromium (total)
- Lead
What handles it
A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”
- NSF/ANSI 53
Claim: Arsenic (Pentavalent)<=50 ppb Reduction
For: Arsenic
Other certifiers’ wording: Arsenic (III) (50 ppb influent level)
- NSF/ANSI 58
Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Uranium
For: Arsenic, Uranium
Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)
At the tap, or for the whole house?
These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.
Filters with those claims on a certifier’s listing
Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money
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
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Interim Enhanced Surface Water Treatment Rule | One cloudiness reading was above the maximum allowed.EPA: Single Turbidity Exceed (Enhanced SWTR) | Jan. 1, 2025 to Jan. 31, 2025 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Jan. 1, 2025 to Jan. 31, 2025 | — | Resolved |
| Lead and Copper Rule Revisions | The required inventory of lead service lines was not completed or submitted on time.EPA: LSL Inventory | Oct. 17, 2024 | — | Unaddressed |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Nov. 1, 2022 to Nov. 30, 2022 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | April 1, 2022 to April 30, 2022 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | March 1, 2022 to March 31, 2022 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Feb. 1, 2022 to Feb. 28, 2022 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Jan. 1, 2022 to Jan. 31, 2022 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Aug. 1, 2021 to Aug. 31, 2021 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | July 1, 2021 to July 31, 2021 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Feb. 1, 2021 to Feb. 28, 2021 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Jan. 1, 2021 to Jan. 31, 2021 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Dec. 1, 2020 to Dec. 31, 2020 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | One cloudiness reading was above the maximum allowed.EPA: Single Turbidity Exceed (Enhanced SWTR) | July 1, 2020 to July 31, 2020 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | July 1, 2020 to July 31, 2020 | — | Resolved |
| Chlorine dioxide | The disinfectant was above its maximum allowed level.EPA: Acute Maximum Residual Disinfectant Level | Aug. 1, 2019 to Aug. 31, 2019 | 0.9 MG/L | Resolved |
| Interim Enhanced Surface Water Treatment Rule | One cloudiness reading was above the maximum allowed.EPA: Single Turbidity Exceed (Enhanced SWTR) | Aug. 1, 2019 to Aug. 31, 2019 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Jan. 1, 2019 to Jan. 31, 2019 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Dec. 1, 2018 to Dec. 31, 2018 | — | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2018 to Dec. 31, 2018 | 0.12 MG/L | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Sept. 1, 2018 to Sept. 30, 2018 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | Aug. 1, 2018 to Aug. 31, 2018 | — | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2018 to Sept. 30, 2018 | 0.07 MG/L | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | July 1, 2018 to July 31, 2018 | — | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2018 to Sept. 30, 2018 | 0.16 MG/L | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | June 1, 2018 to June 30, 2018 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | One cloudiness reading was above the maximum allowed.EPA: Single Turbidity Exceed (Enhanced SWTR) | May 1, 2018 to May 31, 2018 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | May 1, 2018 to May 31, 2018 | — | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2018 to June 30, 2018 | 0.19 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2018 to June 30, 2018 | 0.069 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2018 to June 30, 2018 | 0.081 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2018 to June 30, 2018 | 0.19 MG/L | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | April 1, 2018 to April 30, 2018 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | One cloudiness reading was above the maximum allowed.EPA: Single Turbidity Exceed (Enhanced SWTR) | April 1, 2018 to April 30, 2018 | — | Resolved |
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | March 1, 2018 to March 31, 2018 | — | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2018 to March 31, 2018 | 0.079 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2018 to March 31, 2018 | 0.19 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2017 to Dec. 31, 2017 | 0.17 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2017 to Dec. 31, 2017 | 0.063 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2017 to Sept. 30, 2017 | 0.17 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 125 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Arsenic, uranium, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, nitrate and chromium (total) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. City of Rio Hondo’s own annual report, which it must send you every year, has the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Texas’s results run from March 6, 2020 to Sept. 9, 2026.
Testing your own tap
The lab Texas certifies closest to the area City of Rio Hondo serves, 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 17 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 TexasSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Texas Commission on Environmental Quality, Texas Drinking Water Viewer, results from Jan. 7, 2020 to Oct. 6, 2026, read Oct. 16, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: TCEQ, drinking water laboratories approved for public water system samples, read Oct. 10, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID TX0310006. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Arsenic
- Get the utility’s own reportCity of Rio Hondo must send you a water quality report every year. It covers contaminants this page does not show.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs