Starr County Water Quality: 2 Cities Ranked by the Records

Name: Starr County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

Starr County, Texas: 2 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in Starr County

Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

LithiumDetected in 2 systems10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest45.4 µg/L

CITY OF RIO GRANDE CITY45.4 µg/LSample date: 2024-01-23 to 2024-10-22
CITY OF ROMA38.4 µg/LSample date: 2023-07-25 to 2024-04-30

Perfluorobutanoic acid (PFBA)Detected in 2 systemsNo federal or state limit; shown for transparencyHighest7.2 ng/L

CITY OF ROMA7.2 ng/LSample date: 2023-07-25 to 2024-04-30
CITY OF RIO GRANDE CITY6.1 ng/LSample date: 2024-01-24 to 2024-10-23

29 substances tested, none detected in any systemShow

Tested in these 2 systems: CITY OF RIO GRANDE CITY, CITY OF ROMA

11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
Lead (90th percentile)
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
Perfluoro-3-methoxypropanoic acid (PFMPA)
Perfluoro-4-methoxybutanoic acid (PFMBA)
Perfluorobutanesulfonic acid (PFBS)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluorononanoic acid (PFNA)
Perfluorooctanesulfonic acid (PFOS)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

2 cities

Cities ranked by the records

1
Rio Grande CityCITY OF RIO GRANDE CITY
PFAS detected, within limit
Open city report →
2
RomaCITY OF ROMA
PFAS detected, within limit
Open city report →

Showing 2 of 2 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Starr CountyPFAS detected in 2 of 2 cities; none had a sample above a 2024 EPA limit

4.0 ng/L federal MCL · PFOS, ng/LPFAS in Texas

Lead

0of 2 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Texas

Who supplies the county

Largest water systems

RomaCITY OF ROMA · TX2140007
19,464 served
Rio Grande CityCITY OF RIO GRANDE CITY · TX2140018
18,912 served

Questions

Frequently asked

How does Starr County tap water compare across cities?

PurityMap ranks 2 cities in Starr County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Rio Grande City's main water system: CITY OF RIO GRANDE CITY · PWSID TX2140018 · Purity Score 99 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Starr County cities had a PFAS sample above a 2024 EPA limit?

None of the 2 Starr County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 2.

Is there lead in Starr County tap water?

Utilities report lead as a 90th-percentile result from home taps. 0 of 2 Starr County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Have Starr County water systems had drinking-water violations?

1 city in Starr County has a health-based violation in the federal SDWIS record within about the last ten years. Each city report lists the contaminant, year and whether it was resolved.

Next step

Follow Starr County's water

Get an email when a city record in the county changes.

Find my water

FOLLOW THIS COUNTY

Record changes only

We email when places in Starr County get new results. Unsubscribe any time.

Follow Starr County's water →