EPA data as of Oct 2026 · page updated 2026-10-29

Home hazard report for 92503 — Riverside, CA

ZIP 92503 is served by Western Mwd: no health-based violations since 2016, latest lead result 1.3 ppb, PFAS 3 detected. Riverside County is in EPA radon zone 2.

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Where ZIP 92503 is

Dashed: ZIP area · blue: utility service area · scroll or pinch to zoom
ZIP code areaZIP center Water utility service area PFOA/PFOS ≥ 4 ppt Lead > 15 ppb 5+ violations Superfund site (active) proposed cleaned up Circles: other water systems flagged nearby; size = people served. Tap any symbol for details.

Drinking water: Western Mwd

EPA IDCA3310049
People served87,955
Sourcesurface water (rivers, lakes)
Connections22,327

Health-based violations

No health-based violations reported since 2016.

Full record for Western Mwd →

Other systems overlapping this ZIP: City of Riverside.

Lead

Jan 20231.3 ppb
Jan 20203.1 ppb
Jan 20170 ppb
Jan 20140 ppb
Jan 20110 ppb
Jan 20080 ppb
Jan 20050 ppb
Jan 20049.8 ppb

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”)

CompoundHighest resultSamples with detectionEPA limit
PFPeA4.7 ppt2 of 12—
PFHxS3.4 ppt1 of 12—
PFBS3 ppt1 of 12—
PFOAnot detected0 of 124 ppt MCL
PFBAnot detected0 of 12—
HFPO-DA (GenX)not detected0 of 12—
PFHxAnot detected0 of 12—
PFDAnot detected0 of 12—
PFNAnot detected0 of 12—
PFOSnot detected0 of 124 ppt MCL
PFHpAnot detected0 of 12—

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 Riverside 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 Very High, with very low social vulnerability and very low community resilience.

Riverine floodingVery High
WildfireVery High
EarthquakeRelatively High
Heat waveRelatively Moderate
LandslideRelatively Low
TornadoRelatively Low
Winter weatherRelatively Low
DroughtVery Low
HailVery Low
HurricaneVery Low
LightningVery Low
Strong windVery Low

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

SiteStatusDistance
Alark Hard Chrome
Riverside, California · EPA ID CAD098229214
Active (final NPL)9.0 mi
Stringfellow
Glen Avon Heights, California · EPA ID CAT080012826
Active (final NPL)9.7 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 92503

Who supplies drinking water to ZIP 92503?

Western Mwd (EPA ID CA3310049), a surface water (rivers, lakes) system serving about 87,955 people.

Is there lead in Riverside, CA tap water?

The utility’s latest 90th-percentile lead result (Jan 2023) was 1.3 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 Riverside, CA water have PFAS?

PFAS were detected, with PFOA and PFOS below 4.0 ppt (highest not detected).

Has the water system in 92503 had violations?

No health-based violations reported since 2016.

What natural hazards affect ZIP 92503?

FEMA’s National Risk Index rates the overall natural-hazard risk here as Very High; the highest-rated hazards are riverine flooding (very high), wildfire (very high), earthquake (relatively high).

Are there Superfund sites near 92503?

The nearest active Superfund site is 9.0 miles away. Sites within 10 miles: Alark Hard Chrome (9.0 mi, Active (final NPL)); Stringfellow (9.7 mi, Active (final NPL)).

Is radon a problem in Riverside County?

Riverside 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.