POTRERO ELEMENTARY SCHOOL
High Risk4 PFAS compound(s) exceed EPA Maximum Contaminant Levels
This utility has until 2029 to install treatment under the EPA's April 2024 PFAS rule. In the meantime, a point-of-use filter certified NSF/ANSI 58 for PFOA/PFOS provides reliable interim protection.
9
PFAS Detected
4
Above EPA Limits
1
ZIP Served
Groundwater
Water Source
PFAS Test Results
| Compound | Detected | vs. EPA Limit | EPA Limit | Status |
|---|---|---|---|---|
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 | 95.20ppt | No federal limit | — | Unregulated |
PFHpA Perfluoroheptanoic acid | 72.70ppt | No federal limit | — | Unregulated |
PFPeA Perfluoropentanoic acid | 62.00ppt | No federal limit | — | Unregulated |
PFBA Perfluorobutanoic acid | 13.10ppt | No federal limit | — | Unregulated |
Show 1 more compound detected at low levels
| PFBSPerfluorobutane sulfonic acid | 5.90 ppt | No federal limit |
About this data
Source
EPA UCMR 5 — January 2026 release
Sampling period
January 2023 – December 2025
Water system ID (PWSID)
CA3700963
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor