Sunset Bay
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
- 123 people
- Connections
- 41
- Water source
- Groundwater
- Based in
- Austin, TX
- County
- Aransas
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit, and 3 more are above the health goal. The worst: Total trihalomethanes (TTHM), above the legal limit. 11 health-based violations since 2016.
What handles itWhat was found
Lead and copper: EPA SDWIS monitoring periods ending 2018 to 2025.
Total trihalomethanes (TTHM), arsenic, uranium, haloacetic acids (HAA5), fluoride, nitrate and chromium (total): Texas’s own results, samples taken from Oct. 27, 2021 to Sept. 8, 2026.
Above the legal limit1
Total trihalomethanes (TTHM)
Forms or is added in treatment
270ppb
Highest yearly average, 2022 to 2026
2026 average: 29.5 ppb
Averaged by year, the highest was 270 ppb, in 2024, about 3.4 times EPA’s legal limit of 80 ppb. Its highest single sample was 311 ppb. In 2026, the latest year on file, its three samples averaged 29.5 ppb. EPA recorded violations for total trihalomethanes (TTHM) at this utility in 2023, 2024, 2025 and 2026.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Above the health goal3
Arsenic
Comes from the source
6.3ppb
Highest yearly average, 2021 to 2024
Averaged by year, the highest was 6.3 ppb, in 2024: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That was also the latest year on file.
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
10.6ppb
Highest yearly average, 2021 to 2024
2024, one sample: 10.1 ppb
Averaged by year, the highest was 10.6 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 10.1 ppb.
What handles it
- NSF/ANSI 58 look for “Uranium”
Lead
Comes from pipes, often your own
0.96ppb
90th percentile, 2023 to 2025
In the latest period, 9 in 10 homes sampled were at or below 0.96 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.
What handles it
- NSF/ANSI 53 look for “Lead Reduction”
- NSF/ANSI 58 look for “Lead Reduction”
Below EPA’s limits3
Haloacetic acids (HAA5)
Forms or is added in treatment
28.5ppb
Highest yearly average, 2022 to 2026
2026 average: 7.4 ppb
Averaged by year, the highest was 28.5 ppb, in 2024, below EPA’s legal limit of 60 ppb. Its highest single sample was 58.2 ppb. In 2026, the latest year on file, its three samples averaged 7.4 ppb.
What handles it
No certification claim covers this compound yet.
Fluoride
Forms or is added in treatment
1.2ppm
Highest yearly average, 2021 to 2024
Averaged by year, the highest was 1.2 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.07ppm
Highest sample; found in 4 of 6
2026: not found
The highest sample, in 2022, was 0.07 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in its one sample.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Chromium (total)
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
Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction
For: Total trihalomethanes (TTHM), Arsenic, Lead
Other certifiers’ wording: VOC Reduction; Arsenic (III) (50 ppb influent level)
- NSF/ANSI 58
Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Uranium, Lead Reduction
For: Total trihalomethanes (TTHM), Arsenic, Uranium, Lead
Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)
At the tap, or for the whole house?
Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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
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: Total trihalomethanes (TTHM), Arsenic, Lead
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: Total trihalomethanes (TTHM), Arsenic, Lead
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Total trihalomethanes (TTHM), Arsenic, Lead
Aquasana Clean Water Machine (AQ-CWM2)
Countertop
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM), Lead
Brita Hub Countertop Water Filter System (87340)
Countertop
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
- IAPMO listing:NSF/ANSI 53checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM), Lead
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 0.081 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2025 to Dec. 31, 2025 | 0.13 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 0.15 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2025 to June 30, 2025 | 0.21 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2025 to March 31, 2025 | 0.26 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2024 to Dec. 31, 2024 | 0.27 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2024 to Sept. 30, 2024 | 0.25 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2024 to June 30, 2024 | 0.2 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2024 to March 31, 2024 | 0.21 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2023 to Dec. 31, 2023 | 0.13 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2019 to June 30, 2019 | 0.089 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 11 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), arsenic, uranium, haloacetic acids (HAA5), fluoride, nitrate and chromium (total) results here are Texas’s own from 2021 on, with EPA’s national file for 2012 to 2019. Sunset Bay’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 Oct. 27, 2021 to Sept. 8, 2026.
Testing your own tap
The 3 labs Texas certifies closest to the area Sunset Bay serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Corpus Christi -Nueces County Public Health District Laboratory
Corpus Christi, TX · about 35 miles
Certified for bacteria
Pace Analytical Services, LLC -Dallas TX
Victoria, TX · about 48 miles
Certified for bacteria
Victoria County Public Health Department Water Laboratory
Victoria, TX · about 48 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
- 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 TX0040055. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 4 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Total trihalomethanes (TTHM)
- Get the utility’s own reportSunset Bay 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