Dallas County MUD 4

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: 150 people
Connections: 50
Water source: Surface water bought from another system
Based in: Dallas, TX
County: Dallas
Owner: Local government

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

Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate: Texas’s own results, samples taken from Dec. 13, 2023 to Sept. 17, 2026.

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

34.8ppb

Highest yearly average, 2024 to 2026

2026, one sample: 24.7 ppb

Averaged by year, the highest was 34.8 ppb, in 2024, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 24.7 ppb.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

43.8ppb

Highest yearly average, 2024 to 2026

Averaged by year, the highest was 43.8 ppb, in 2026, below EPA’s legal limit of 80 ppb. That was also the latest year on file.

What handles it

NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Nitrate

Comes from the source

Below EPA’s limits

0.78ppm

Highest sample; found in 12 of 12

2026 average: 0.42 ppm

The highest sample, in 2024, was 0.78 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its three samples averaged 0.42 ppm.

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.

Lead

Violations since 2016

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

What this report can’t tell you

Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate results here are Texas’s own from 2023 on, with EPA’s national file for 2012 to 2019. Dallas County MUD 4’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 Dec. 13, 2023 to Sept. 17, 2026.

Testing your own tap

Dallas County MUD 4’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.

No lab Texas certifies is within 75 miles of the area Dallas County MUD 4 serves on the state’s list. Some take samples by mail; the state’s page lists them all.

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