CheckPFAS

ZIP Code 91963

High Risk
High Risk PFAS Risk Level

PFAS above EPA limits detected

4 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.

9
PFAS Detected
4
Above EPA Limits
1
Water System
4708%
Highest % of MCL

Compounds Exceeding EPA Limits

PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 4708% of limit
Detected: 188.30 ppt
PFHxS Exceeds EPA limit
0 ppt MCL: 10 ppt 2502% of limit
Detected: 250.20 ppt
PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 1605% of limit
Detected: 64.20 ppt
PFNA Exceeds EPA limit
0 ppt MCL: 10 ppt 102% of limit
Detected: 10.20 ppt

POTRERO ELEMENTARY SCHOOL

CA3700963 High Risk
Water Type
Groundwater
PFAS Detected
9
Above MCL
4
State
California
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOA
Perfluorooctanoic acid
188.30ppt
4708% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
250.20ppt
2502% of limit
10 ppt⚠ Exceeds MCL
PFOS
Perfluorooctane sulfonic acid
64.20ppt
1605% of limit
4 ppt⚠ Exceeds MCL
PFNA
Perfluorononanoic acid
10.20ppt
102% of limit
10 ppt⚠ Exceeds MCL
PFHxA
Perfluorohexanoic acid
95.20pptNo federal limitUnregulated
PFHpA
Perfluoroheptanoic acid
72.70pptNo federal limitUnregulated
PFPeA
Perfluoropentanoic acid
62.00pptNo federal limitUnregulated
PFBA
Perfluorobutanoic acid
13.10pptNo federal limitUnregulated
Show 1 more compound detected at low levels
PFBSPerfluorobutane sulfonic acid5.90 pptNo federal limit

Data source: EPA Unregulated Contaminant Monitoring Rule, 5th cycle (UCMR 5) — January 2026 release.

UCMR 5 tested ~10,000 public water systems serving more than 25 people between 2023-2025 for 29 PFAS compounds.

Detection values represent the highest single-sample result measured at entry points to the distribution system.

View raw EPA data →