Riderville 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: 837 people
Connections: 279
Water source: Surface water bought from another system
Based in: Carthage, TX
County: Panola
Owner: Local government

The ZIP code it serves

75633

The short answer

1 result is above EPA’s legal limit. The worst: Haloacetic acids (HAA5), above the legal limit. 5 health-based violations since 2016.

What was found

Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate: Texas’s own results, samples taken from March 11, 2020 to July 14, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Haloacetic acids (HAA5)

Forms or is added in treatment

Above the legal limit

65.4ppb

Highest yearly average, 2020 to 2026

2026 average: 6.5 ppb

Averaged by year, the highest was 65.4 ppb, in 2024, above EPA’s legal limit of 60 ppb. Its highest single sample was 113 ppb. In 2026, the latest year on file, its three samples averaged 6.5 ppb. EPA recorded violations for haloacetic acids (HAA5) at this utility in 2023, 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 46.6 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

73.6ppb

Highest yearly average, 2020 to 2026

2026 average: 10.8 ppb

Averaged by year, the highest was 73.6 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 126 ppb. In 2026, the latest year on file, its three samples averaged 10.8 ppb. EPA recorded no violation for total trihalomethanes (TTHM) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 72.2 ppb, in 2015.

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

0.53ppm

Highest sample; found in 7 of 7

2026, one sample: 0.44 ppm

The highest sample, in 2021, was 0.53 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.44 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

Contaminant or rule	Type	Period	Measured	Status
Total Haloacetic Acids (HAA5)	The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average	July 1, 2025 to Sept. 30, 2025	0.063 MG/L	Resolved
Total Haloacetic Acids (HAA5)	The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average	April 1, 2025 to June 30, 2025	0.066 MG/L	Resolved
Total Haloacetic Acids (HAA5)	The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average	Jan. 1, 2025 to March 31, 2025	0.08 MG/L	Resolved
Total Haloacetic Acids (HAA5)	The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average	Oct. 1, 2024 to Dec. 31, 2024	0.065 MG/L	Resolved
Total Haloacetic Acids (HAA5)	The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average	Jan. 1, 2023 to March 31, 2023	0.067 MG/L	Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 7 monitoring or reporting violations not shown.

What this report can’t tell you

Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Riderville 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 March 11, 2020 to July 14, 2026.

Testing your own tap

Riderville 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 Riderville WSC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

Southern Petroleum Laboratories (SPL), Inc. (FKA Ana-Lab Corporation)
Kilgore, TX · about 39 miles
Certified for bacteria, lead and copper
(903) 984-0551
Eastex Environmental Lab, Inc.-Nacogdoches
Nacogdoches, TX · about 42 miles
Certified for bacteria
(936) 569-8879
Environmental Monitoring Lab
Winona, TX · about 54 miles
Certified for bacteria
(903) 877-9222

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