Skip to content
TapBuff
ZIP

City of Mason

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
2,228 people
Connections
1,327
Water source
Groundwater
Based in
Mason, TX
County
Mason
Owner
Local government
The ZIP code it serves

76856

The short answer

2 results are above the health goal. The worst: Lead, above the health goal. 52 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 1995 to 2025.

Uranium, nitrate, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), arsenic and chromium (total): Texas’s own results, samples taken from Feb. 19, 2020 to May 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Lead

Comes from pipes, often your own

Above the health goal

1.5ppb

90th percentile, 2025

In the latest period, 9 in 10 homes sampled were at or below 1.5 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

Uranium

Comes from the source

Above the health goal

0.9ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 0.9 ppb, in 2020: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 1.7 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 2013.

What handles it

Below EPA’s limits4

Nitrate

Comes from the source

Below EPA’s limits

2.6ppm

Highest sample; found in 8 of 8

2026, one sample: 2.4 ppm

The highest sample, in 2025, was 2.6 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 2.4 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 1.9 ppm, in 2019.

What handles it

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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

10.8ppb

Highest yearly average, 2020 to 2026

2026, one sample: 5.6 ppb

Averaged by year, the highest was 10.8 ppb, in 2020, below EPA’s legal limit of 80 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 2.6 ppb, in 2019.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.47ppm

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 0.47 ppm, in 2020, 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 0.51 ppm, in 2014.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

3.5ppb

Highest yearly average, 2020 to 2026

2026, one sample: 1.6 ppb

Averaged by year, the highest was 3.5 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 1.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.5 ppb, in 2014.

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.
  • Arsenic
  • 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.”

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

Compare five-year costs

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Revised Total Coliform RuleColiform results required a check of the system, and the check or its fixes were not done on time.EPA: Treatment Technique, Level 1 Assessment (RTCR)April 11, 2026—Unaddressed
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2026 to March 31, 20266.0 PCI/LArchived
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2022 to Dec. 31, 202216 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2022 to June 30, 202216 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2022 to March 31, 202216 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2021 to Dec. 31, 20216.0 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2021 to Sept. 30, 20216.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2021 to Sept. 30, 202118 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2021 to June 30, 20216.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2021 to June 30, 202118 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2021 to March 31, 20216.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2021 to March 31, 202117 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2020 to Dec. 31, 202018 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2020 to Dec. 31, 20206.0 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2020 to Sept. 30, 20206.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2020 to Sept. 30, 202017 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 20206.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 202016 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2020 to March 31, 20206.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2020 to March 31, 202018 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2019 to Dec. 31, 20196.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2019 to Dec. 31, 201918 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2019 to Sept. 30, 20196.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2019 to Sept. 30, 201918 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2019 to June 30, 20196.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2019 to June 30, 201919 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2019 to March 31, 20196.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2019 to March 31, 201919 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2018 to Dec. 31, 201819 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2018 to Dec. 31, 20186.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2018 to Sept. 30, 201820 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2018 to Sept. 30, 20186.0 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2018 to June 30, 20186.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2018 to June 30, 201820 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2018 to March 31, 201821 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2018 to March 31, 20186.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2017 to Dec. 31, 201720 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2017 to Dec. 31, 20176.0 PCI/LResolved
Gross alpha radiation (excluding radon and uranium)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2017 to Sept. 30, 201719 PCI/LResolved
Combined Radium (-226 and -228)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2017 to Sept. 30, 20176.0 PCI/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 21 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Uranium, nitrate, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), arsenic and chromium (total) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. City of Mason’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. 19, 2020 to May 21, 2026.

Testing your own tap

City of Mason’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 lab Texas certifies closest to the area City of Mason 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 35 miles

    Certified for bacteria

    (325) 247-3295

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

Sources

PWSID TX1600001. Rebuilt from EPA data on Oct. 18, 2026.

Nearby

All Texas utilities

What to do next