PFAS test results
Highest average at any one sampling point, from EPA's UCMR 5 testing (2023–2024), against the levels EPA set in 2024. ND = not detected above EPA's reporting level. EPA's comparison rounds like this: an average of 4.05 ppt or more counts as above the 4 ppt PFOA/PFOS limit, and 15 ppt or more counts as above the 10 ppt level for PFHxS, PFNA and GenX.
Hazard index (PFHxS, PFNA, GenX, PFBS mix): 0.09 (limit 1, EPA comparison threshold 1.5).
All 6 detected compounds at this system (single highest result)
| Compound | Highest result | Results above reporting level |
|---|---|---|
| lithium | 50 µg/L | 26 of 26 |
| PFBA | 12.2 ppt | 12 of 26 |
| PFPeA | 3.8 ppt | 2 of 26 |
| PFHxA | 3.5 ppt | 2 of 26 |
| PFHxS | 3.4 ppt | 1 of 26 |
| PFBS | 3 ppt | 1 of 26 |
Read this as a screening result, not a compliance finding. UCMR 5 samples are occurrence data. Legal compliance is judged on a running annual average from the utility's own monitoring, reported to the state. PFOA and PFOS at 4 ppt are in force; EPA has proposed to rescind the PFHxS, PFNA, GenX and hazard-index levels.
Violations and lead
2 health-based violations began since 2021-10-26 (2 limit exceedances, 0 treatment-technique; 0 still open). Most recent began 2025-10-01.
| Contaminant group | Violations |
|---|---|
| Disinfection byproducts | 2 |
Health-based means a limit exceedance or a missed treatment requirement. Many violations are fixed within weeks; a count says nothing about severity. Missed-sample (monitoring) violations are not counted.
Lead 90th percentile: 0.0 ppb for the period ending 2023-12-31 (action level 15 ppb). This is a system-wide statistic, not your home's tap; lead usually comes from household plumbing and service lines.
Lithium: highest result 50 µg/L. EPA's non-regulatory reference concentration is 10 µg/L (results above 15 are counted as above it). Lithium has no federal drinking-water limit.
What helps, and what does not
Match the filter to the contaminant, not the other way round. See the filter-fit table.
Common questions
Is the tap water in North Alamo Wsc safe to drink?
PFAS were detected at North Alamo Wsc, but every regulated compound averaged under its limit. 2 health-based violations recorded since 2021-10-26 (0 not yet closed). Lead 90th percentile 0.0 ppb in the sampling period ending 2023-12-31 (action level 15 ppb). This is a summary of public EPA data, not a guarantee about the water at your tap.
Does North Alamo Wsc have PFAS in its water?
Yes. EPA's 2023–2025 testing detected 5 of 29 PFAS compounds at North Alamo Wsc.
Not medical or legal advice. Results describe the utility's system, not your tap. Compare with your utility's annual Consumer Confidence Report.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.