Cassie Water System
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
- 106 people
- Connections
- 66
- Water source
- Groundwater influenced by surface water
- Based in
- Saint Louis, TX
- County
- Burnet
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit, and 2 more are above the health goal. The worst: Copper, above the action level. 162 health-based violations since 2016.
What handles itWhat was found
Lead and copper: EPA SDWIS monitoring periods ending 2021 to 2025.
Arsenic, uranium, nitrate, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total): Texas’s own results, samples taken from Feb. 12, 2020 to Oct. 5, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit1
Copper
Comes from pipes, often your own
3.9ppm
90th percentile, 2025
In the latest period, 9 in 10 homes sampled were at or below 3.9 ppm, above EPA’s action level of 1.3 ppm.
What handles it
- NSF/ANSI 53 look for “Copper Reduction”
- NSF/ANSI 58 look for “Copper Reduction”
Above the health goal2
Arsenic
Comes from the source
5.6ppb
Highest yearly average, 2020 to 2026
2026: not found
Averaged by year, the highest was 5.6 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 5.7 ppb. In 2026, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.2 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
4.5ppb
Highest yearly average, 2021 to 2024
Averaged by year, the highest was 4.5 ppb, in 2024: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 6.4 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.6 ppb, in 2018.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits4
Nitrate
Comes from the source
10.2ppm
Highest sample; found in 57 of 57
2026 average: 6.3 ppm
The highest sample, in 2024, was 10.2 ppm, which EPA rounds to 10 ppm to compare: at its legal limit of 10 ppm, not above it. In 2026, the latest year on file, its 10 samples averaged 6.3 ppm. EPA recorded no violation for nitrate at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 12.9 ppm, in 2016, and EPA recorded a violation in 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Fluoride
Forms or is added in treatment
1.4ppm
Highest yearly average, 2020 to 2026
2026 average: 1.2 ppm
Averaged by year, the highest was 1.4 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.4 ppm. In 2026, the latest year on file, its two samples averaged 1.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.4 ppm, in 2019.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Total trihalomethanes (TTHM)
Forms or is added in treatment
25.6ppb
Highest yearly average, 2020 to 2026
2026, one sample: 24.3 ppb
Averaged by year, the highest was 25.6 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 24.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 13.4 ppb, in 2016.
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
6.0ppb
Highest yearly average, 2020 to 2026
2026, one sample: 5.6 ppb
Averaged by year, the highest was 6.0 ppb, in 2021, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 5.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.4 ppb, in 2016.
What handles it
No certification claim covers this compound yet.
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
Claims: Copper Reduction, Arsenic (Pentavalent)<=50 ppb Reduction
For: Copper, Arsenic
Other certifiers’ wording: Arsenic (III) (50 ppb influent level)
- NSF/ANSI 58
Claims: Copper Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Uranium
For: Copper, Arsenic, Uranium
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: Copper, 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: Copper, Arsenic
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Copper, Arsenic
Brita Tahoe Pitcher with Original Filter (OB60, OB03)
Pitcher
- WQA listing:NSF/ANSI 42NSF/ANSI 53checked Oct. 13, 2026
Certified for: Copper
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | May 1, 2026 to May 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | May 1, 2026 to May 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | April 1, 2026 to April 30, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | April 1, 2026 to April 30, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | March 1, 2026 to March 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | March 1, 2026 to March 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2026 to Feb. 28, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2026 to Feb. 28, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2026 to Jan. 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2026 to Jan. 31, 2026 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Dec. 1, 2025 to Dec. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Dec. 1, 2025 to Dec. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Nov. 1, 2025 to Nov. 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Nov. 1, 2025 to Nov. 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Oct. 1, 2025 to Oct. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Oct. 1, 2025 to Oct. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Sept. 1, 2025 to Sept. 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Sept. 1, 2025 to Sept. 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Aug. 1, 2025 to Aug. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Aug. 1, 2025 to Aug. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | July 1, 2025 to July 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | July 1, 2025 to July 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | June 1, 2025 to June 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | June 1, 2025 to June 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | May 1, 2025 to May 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | May 1, 2025 to May 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | April 1, 2025 to April 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | April 1, 2025 to April 30, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | March 1, 2025 to March 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | March 1, 2025 to March 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2025 to Feb. 28, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2025 to Feb. 28, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2025 to Jan. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2025 to Jan. 31, 2025 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Dec. 1, 2024 to Dec. 31, 2024 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Dec. 1, 2024 to Dec. 31, 2024 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Nov. 1, 2024 to Nov. 30, 2024 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Nov. 1, 2024 to Nov. 30, 2024 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Oct. 1, 2024 to Oct. 31, 2024 | — | Archived |
| Long Term 2 Enhanced Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Oct. 1, 2024 to Oct. 31, 2024 | — | Archived |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 246 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Arsenic, uranium, nitrate, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Cassie Water System’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 Feb. 12, 2020 to Oct. 5, 2026.
Testing your own tap
The 3 labs Texas certifies closest to the area Cassie Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Environmental Monitoring Lab
Llano, TX · about 25 miles
Certified for bacteria
Integrity Testing, Inc.
Austin, TX · about 42 miles
Certified for lead and copper
Texas Department of State Health Services Laboratory Services Section
Austin, TX · about 46 miles
Certified for bacteria, lead and copper
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 TX0270047. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 3 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Copper
- Get the utility’s own reportCassie Water System 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