CheckPFAS

ZIP 78665 · Texas

Sandy, TX

High Risk

11 compounds detected

Above EPA drinking water limits

PFOS Exceeds limit
12.40 ppt (310% of MCL)
→ 3.1× MCL
0 MCL: 4 ppt 12.4 ppt
PFNA Exceeds limit
24.30 ppt (243% of MCL)
→ 2.4× MCL
0 MCL: 10 ppt 24.3 ppt
PFOA Exceeds limit
5.90 ppt (148% of MCL)
0 MCL: 4 ppt 6 ppt
PFHxS
7.00 ppt (70% of MCL)
0 MCL: 10 ppt 15 ppt
lithium no federal limit
83800.00 ppt
0 125700 ppt
PFPeA no federal limit
21.20 ppt
0 31.8 ppt
PFBA no federal limit
15.80 ppt
0 23.8 ppt
PFBS no federal limit
10.00 ppt
0 15 ppt
PFHxA no federal limit
9.20 ppt
0 13.8 ppt
PFHpA no federal limit
4.30 ppt
0 6.5 ppt
PFUnA no federal limit
2.70 ppt
0 4.1 ppt
Above EPA limit Below EPA limit No federal limit EPA MCL

Above EPA Limits

6 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.

PFAS Detected
43
Above EPA Limits
6
Water Systems
9
Highest % of MCL
310%

Plain English

01What this means for you

One or more PFAS compounds were measured above the EPA's enforceable drinking water limit at a utility serving ZIP 78665. 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.

What to do next

02Three concrete steps

  1. 01

    Install a certified filter

    A reverse osmosis or NSF/ANSI 58-certified carbon block at your kitchen tap is the most reliable solution. Standard pitcher filters (Brita, PUR) don't remove PFAS unless explicitly certified for it. See certified filter picks →

  2. 02

    Read your utility's CCR

    Your water utility publishes an annual Consumer Confidence Report covering the previous year's water quality, including their PFAS treatment plan if any. More detailed than this site's summary. How to read a CCR →

  3. 03

    Reduce other exposure routes

    Water isn't the only input. Replace badly-scratched non-stick pans, skip microwave popcorn bags and greaseproof fast-food wrappers, and choose stainless or cast iron cookware. Full action plan on the FAQ →

Filter Recommendations

Find the right filter for your water
See our tested & reviewed PFAS-certified filters, ranked by CheckPFAS Score

CheckPFAS earns a small commission on filter purchases at no cost to you. Ranked by performance, not commission. Affiliate disclosure.

02MANVILLE WSC

High Risk

PWSID · TX2270033

Water Type
Groundwater
PFAS Detected
11
Above MCL
3
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
12.40ppt
310% of limit
4 pptExceeds MCL
PFNA
Perfluorononanoic acid
24.30ppt
243% of limit
10 pptExceeds MCL
PFOA
Perfluorooctanoic acid
5.90ppt
148% of limit
4 pptExceeds MCL
PFHxS
Perfluorohexane sulfonic acid
7.00ppt
70% of limit
10 pptBelow limit
lithium
83800.00pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
10.00pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
9.10pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
8.70pptNo federal limitUnregulated
Show 3 more compounds detected at low levels
PFBAPerfluorobutanoic acid7.40 pptNo federal limit
PFHpAPerfluoroheptanoic acid4.30 pptNo federal limit
PFUnAPerfluoroundecanoic acid2.70 pptNo federal limit

03TRAVIS COUNTY WCID 18

Low Level

PWSID · TX2270083

Water Type
Surface Water
PFAS Detected
2
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFBA
Perfluorobutanoic acid
8.20pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
3.10pptNo federal limitUnregulated

04TRAVIS COUNTY WCID 10

High Risk

PWSID · TX2270182

Water Type
Surface Water
PFAS Detected
5
Above MCL
1
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
5.50ppt
138% of limit
4 pptExceeds MCL
PFHxS
Perfluorohexane sulfonic acid
4.00ppt
40% of limit
10 pptBelow limit
PFBA
Perfluorobutanoic acid
9.90pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
3.40pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
3.10pptNo federal limitUnregulated

05TRAVIS COUNTY MUD 18

Low Level

PWSID · TX2270403

Water Type
Surface Water
PFAS Detected
1
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFBA
Perfluorobutanoic acid
8.60pptNo federal limitUnregulated

06CITY OF ROUND ROCK

Moderate

PWSID · TX2460003

Water Type
Groundwater
PFAS Detected
5
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
lithium
13500.00pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
6.70pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
6.70pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
5.10pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
3.70pptNo federal limitUnregulated

07JONAH WATER SUD

High Risk

PWSID · TX2460022

Water Type
Groundwater
PFAS Detected
8
Above MCL
2
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
5.70ppt
143% of limit
4 pptExceeds MCL
PFOA
Perfluorooctanoic acid
5.10ppt
128% of limit
4 pptExceeds MCL
PFHxS
Perfluorohexane sulfonic acid
5.60ppt
56% of limit
10 pptBelow limit
lithium
38600.00pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
21.20pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
15.80pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
9.30pptNo federal limitUnregulated
PFHxA
Perfluorohexanoic acid
9.20pptNo federal limitUnregulated

08WILLIAMSON COUNTY MUD 10

Low Level

PWSID · TX2460145

Water Type
Surface Water
PFAS Detected
4
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
lithium
16900.00pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
5.60pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
3.80pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
3.00pptNo federal limitUnregulated

09WILLIAMSON COUNTY WSID 3

Low Level

PWSID · TX2460152

Water Type
Groundwater
PFAS Detected
4
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFNA
Perfluorononanoic acid
5.00ppt
50% of limit
10 pptBelow limit
lithium
71800.00pptNo federal limitUnregulated
PFBS
Perfluorobutane sulfonic acid
3.50pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
3.10pptNo federal limitUnregulated

010WILLIAMSON COUNTY MUD 11

Low Level

PWSID · TX2460159

Water Type
Surface Water
PFAS Detected
3
Above MCL
0
State
Texas
Data Period
2023–2025

PFAS test results

CompoundDetectedvs. EPA LimitEPA LimitStatus
lithium
11600.00pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
5.60pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
3.00pptNo federal limitUnregulated

Note: ZIP code 78665 is served by 9 separate water utilities. Results above show data for each system independently.

Source & Methodology

About this data

Source
EPA UCMR 5
Data released
January 2026
Sampling period
January 2023 – December 2025
Systems tested
~10,000 public water systems
Water systems (PWSID)
TX2270033 · TX2270083 · TX2270182 · TX2270403 · TX2460003 · TX2460022 · TX2460145 · TX2460152 · TX2460159
Detection threshold (MRL)
~1.5–2 ppt

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. "Not detected" means below the MRL, not literally zero.

View raw EPA UCMR 5 occurrence data →

Related

More resources for your area

  1. 01

    How to read your utility's CCR

    Decode your annual Consumer Confidence Report

  2. 02

    On a private well?

    PFAS testing guide for well owners — EPA rules don't apply

  3. 03

    All water systems in Texas

    Compare utilities statewide

  4. 04

    Which filter removes PFAS?

    Compare every method by removal rate & NSF certification

  5. 05

    PFAS health effects

    What the science shows, condition by condition

  6. 06

    PFAS compound guide

    Health effects & EPA limits for each compound