Home hazard report for 94538 — Fremont, CA
ZIP 94538 is served by Alameda County Water District: no health-based violations since 2016, latest lead result 0 ppb, PFAS not detected. Alameda County is in EPA radon zone 2.
No health-based violations reported since 2016.
90th-percentile lead in the latest round (Jan 2022). Lead comes mostly from household plumbing and service lines, so individual homes can be higher.
None of the tested PFAS were found above EPA’s reporting limits in 2023–2025.
Predicted average indoor radon between 2 and 4 pCi/L. Test your home; many homes here exceed 4 pCi/L.
FEMA’s overall natural-hazard risk for this census tract, relative to the rest of the U.S.
The nearest active Superfund site is 5.1 miles away.
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Where ZIP 94538 is
Dashed: ZIP area · blue: utility service area · scroll or pinch to zoomDrinking water: Alameda County Water District
Health-based violations
No health-based violations reported since 2016.
Lead
90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.
PFAS (“forever chemicals”)
| Compound | Highest result | Samples with detection | EPA limit |
|---|---|---|---|
| PFBA | not detected | 0 of 14 | — |
| HFPO-DA (GenX) | not detected | 0 of 14 | — |
| PFHxA | not detected | 0 of 14 | — |
| PFPeA | not detected | 0 of 14 | — |
| PFDA | not detected | 0 of 14 | — |
| PFOA | not detected | 0 of 14 | 4 ppt MCL |
| PFOS | not detected | 0 of 14 | 4 ppt MCL |
| PFNA | not detected | 0 of 14 | — |
| PFHxS | not detected | 0 of 14 | — |
| PFHpA | not detected | 0 of 14 | — |
| PFBS | not detected | 0 of 14 | — |
EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), samples 2023–2025; ppt = parts per trillion (ng/L). The 4.0 ppt maximum contaminant levels for PFOA and PFOS were set by EPA in 2024; water systems have until the end of the decade to comply.
Radon in Alameda County
EPA radon zone 2 — moderate potential. Predicted average indoor radon between 2 and 4 pCi/L. Test your home; many homes here exceed 4 pCi/L.
Radon is a colorless, odorless radioactive gas from soil and rock, and the leading cause of lung cancer among non-smokers. EPA recommends fixing a home at 4 pCi/L or above and considering it from 2 pCi/L. A short-term test kit costs about $15–30. How radon zones work →
Natural hazard risk
FEMA rates the overall natural-hazard risk of this neighborhood (census tract) as Relatively Moderate, with very low social vulnerability and very high community resilience.
FEMA National Risk Index (December 2025): expected annual losses from each hazard combined with social vulnerability and community resilience, rated relative to all U.S. census tracts. Hazards not listed are not applicable here. It describes the area, not a single building; flood insurance maps (FEMA FIRMs) decide flood-insurance requirements.
Live conditions: river gauges and flood levels · tornado warnings · wildfire detections · earthquakes — our sister maps, updated from NOAA, USGS and NASA every few minutes.
Superfund sites nearby
| Site | Status | Distance |
|---|---|---|
| South Bay Asbestos Area Alviso, California · EPA ID CAD980894885 | Active (final NPL) | 5.1 mi |
| Moffett Naval Air Station Sunnyvale, California · EPA ID CA2170090078 | Active (final NPL) | 8.1 mi |
| Advanced Micro Devices, Inc. (Building 915) Sunnyvale, California · EPA ID CAT080034234 | Active (final NPL) | 8.4 mi |
| TRW Microwave, Inc. (Building 825) Sunnyvale, California · EPA ID CAD009159088 | Active (final NPL) | 8.6 mi |
| Monolithic Memories Sunnyvale, California · EPA ID CAD049236201 | Active (final NPL) | 8.6 mi |
| Synertek, Inc. (Building 1) Santa Clara, California · EPA ID CAD990832735 | Active (final NPL) | 8.6 mi |
| Applied Materials Santa Clara, California · EPA ID CAD042728840 | Active (final NPL) | 8.6 mi |
| Advanced Micro Devices, Inc. Sunnyvale, California · EPA ID CAD048634059 | Active (final NPL) | 8.7 mi |
| Fairchild Semiconductor Corp. (Mountain View Plant) Mountain View, California · EPA ID CAD095989778 | Active (final NPL) | 8.7 mi |
| Intel Magnetics Santa Clara, California · EPA ID CAD092212497 | Active (final NPL) | 8.8 mi |
EPA Superfund National Priorities List (NPL): the country’s most serious known hazardous-waste sites, each with an EPA cleanup record (linked). Distance is measured from the ZIP center to the site’s reference point; being near a site does not by itself mean exposure — EPA site pages describe what was found and how it is being cleaned up.
What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.
Questions about 94538
Who supplies drinking water to ZIP 94538?
Alameda County Water District (EPA ID CA0110001), a surface water (rivers, lakes) system serving about 344,000 people.
Is there lead in Fremont, CA tap water?
The utility’s latest 90th-percentile lead result (Jan 2022) was 0 ppb; EPA’s action level is 15 ppb, falling to 10 ppb from 2027. Lead mostly comes from service lines and home plumbing, so the only way to know your tap is to test it.
Does Fremont, CA water have PFAS?
None of the tested PFAS were found above EPA’s reporting limits in 2023–2025.
Has the water system in 94538 had violations?
No health-based violations reported since 2016.
What natural hazards affect ZIP 94538?
FEMA’s National Risk Index rates the overall natural-hazard risk here as Relatively Moderate; the highest-rated hazards are earthquake (relatively high), drought (relatively low), heat wave (relatively low).
Are there Superfund sites near 94538?
The nearest active Superfund site is 5.1 miles away. Sites within 10 miles: South Bay Asbestos Area (5.1 mi, Active (final NPL)); Moffett Naval Air Station (8.1 mi, Active (final NPL)); Advanced Micro Devices, Inc. (Building 915) (8.4 mi, Active (final NPL)).
Is radon a problem in Alameda County?
Alameda County is in EPA radon zone 2 (moderate potential). Predicted average indoor radon between 2 and 4 pCi/L. Test your home; many homes here exceed 4 pCi/L.