Starr WSC

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: 3,100 people
Connections: 1,000
Water source: Groundwater
Based in: Denison, TX
County: Grayson
Owner: Local government

The ZIP code it serves

75021

The short answer

Nothing in EPA’s and Texas’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5), chromium (total), nitrate, arsenic and uranium: Texas’s own results, samples taken from Sept. 29, 2020 to July 20, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits5

Fluoride

Forms or is added in treatment

Below EPA’s limits

2.2ppm

Highest yearly average, 2020 to 2026

2026 average: 1.7 ppm

Averaged by year, the highest was 2.2 ppm, in 2023, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 2.4 ppm. In 2026, the latest year on file, its three samples averaged 1.7 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.8 ppm, in 2017.

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

Below EPA’s limits

23.2ppb

Highest yearly average, 2020 to 2026

2026, one sample: 14.9 ppb

Averaged by year, the highest was 23.2 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 14.9 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 16.1 ppb, in 2019.

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

Below EPA’s limits

3.7ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 3.7 ppb, in 2023, below EPA’s legal limit of 60 ppb. 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 1.3 ppb, in 2016.

What handles it

No certification claim covers this compound yet.

Chromium (total)

Comes from the source

Below EPA’s limits

3.5ppb

Highest yearly average, 2021 to 2024

2024 average: 1.3 ppb

Averaged by year, the highest was 3.5 ppb, in 2021, below EPA’s legal limit of 100 ppb. Its highest single sample was 14 ppb. In 2024, the latest year on file, its four samples averaged 1.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2015.

What handles it

NSF/ANSI 58 look for “Chromium (Hexavalent) Reduction”
NSF/ANSI 53 look for “Chromium Reduction”

Nitrate

Comes from the source

Below EPA’s limits

0.083ppm

Highest sample; found in 28 of 28

2026 average: 0.046 ppm

The highest sample, in 2022, was 0.083 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its four samples averaged 0.046 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.17 ppm, in 2017.

What handles it

NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.

Arsenic
Lead
Uranium

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

Everything else. Fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5), chromium (total), nitrate, arsenic and uranium results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Starr WSC’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 Sept. 29, 2020 to July 20, 2026.

Testing your own tap

Starr WSC’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Texas certifies.

The 3 labs Texas certifies closest to the area Starr WSC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

Pace Analytical Services, LLC -Dallas TX
Allen, TX · about 44 miles
Certified for bacteria
(972) 727-1123
Southern Petroleum Laboratories, Inc. - Plano
Plano, TX · about 49 miles
Certified for bacteria, lead and copper
(972) 424-6422
Eurofins Xenco, LLC -Dallas
Dallas, TX · about 64 miles
Certified for bacteria
(281) 240-4200

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 Texas