CheckPFAS

ZIP Code 79510

High Risk
High Risk PFAS Risk Level

PFAS above EPA limits detected

9 compounds exceed EPA Maximum Contaminant Levels in water serving this ZIP code. Standard pitcher filters like Brita do not remove PFAS. See filter recommendations below.

28
PFAS Detected
9
Above EPA Limits
3
Water Systems
525%
Highest % of MCL

Compounds Exceeding EPA Limits

PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 375% of limit
Detected: 15.00 ppt
PFHxS Exceeds EPA limit
0 ppt MCL: 10 ppt 225% of limit
Detected: 22.50 ppt
PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 143% of limit
Detected: 5.70 ppt

What this means for you

One or more PFAS compounds were measured above the EPA's enforceable drinking water limit at a utility serving ZIP 79510. The EPA set these limits because long-term exposure at higher concentrations is associated with health effects including immune suppression, thyroid changes, and cancer risk increases. Standard pitcher filters (Brita, PUR) are not certified to remove PFAS. The most reliable at-home options are under-sink reverse osmosis systems or activated carbon block filters with an NSF/ANSI 58 certification specifically listing PFOA/PFOS reduction. Your water utility is required to bring levels into compliance by 2029 — filtering at the tap is the practical interim step if you'd like additional protection now.

CITY OF CLYDE

TX0300002 High Risk
Water Type
Surface Water
PFAS Detected
10
Above MCL
3
State
Texas
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
15.00ppt
375% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
22.50ppt
225% of limit
10 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
5.70ppt
143% of limit
4 ppt⚠ Exceeds MCL
lithium
15100.00pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
16.40pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
14.80pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
14.50pptNo federal limitUnregulated
PFHpA
Perfluoroheptanoic acid
7.60pptNo federal limitUnregulated
Show 2 more compounds detected at low levels
PFBSPerfluorobutane sulfonic acid6.20 pptNo federal limit
6:2 FTS6:2 Fluorotelomer sulfonic acid6.20 pptNo federal limit

EULA WSC

TX0300005 High Risk
Water Type
Surface Water
PFAS Detected
9
Above MCL
3
State
Texas
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
20.00ppt
500% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
21.30ppt
213% of limit
10 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
6.20ppt
155% of limit
4 ppt⚠ Exceeds MCL
lithium
11900.00pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
31.00pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
16.00pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
13.00pptNo federal limitUnregulated
PFHpA
Perfluoroheptanoic acid
7.50pptNo federal limitUnregulated
Show 1 more compound detected at low levels
PFBSPerfluorobutane sulfonic acid5.90 pptNo federal limit

POTOSI WSC

TX2210008 High Risk
Water Type
Surface Water
PFAS Detected
9
Above MCL
3
State
Texas
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
21.00ppt
525% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
19.90ppt
199% of limit
10 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
6.70ppt
168% of limit
4 ppt⚠ Exceeds MCL
lithium
15100.00pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
22.00pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
15.70pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
13.60pptNo federal limitUnregulated
PFHpA
Perfluoroheptanoic acid
8.70pptNo federal limitUnregulated
Show 1 more compound detected at low levels
PFBSPerfluorobutane sulfonic acid6.10 pptNo federal limit
Note: ZIP code 79510 is served by 3 separate water utilities. Results above show data for each system independently.
About this data
Source
EPA UCMR 5 (Unregulated Contaminant Monitoring Rule, 5th cycle)
Data released
January 2026
Sampling period
January 2023 – December 2025
Systems tested
~10,000 public water systems serving > 25 people
Water systems (PWSID)
TX0300002, TX0300005, TX2210008
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor, not zero

Values shown are the highest single-sample concentration measured at entry points to the distribution system. Results reflect water quality at the treatment plant — aging pipes, building plumbing, and on-site storage can affect what actually reaches your tap.