San Mateo County, California — Property Hazard, Flood Zone, Soil, Water & EPA Guide
What Are the Flood, Soil Foundation & EPA Risks in San Mateo County, CA?
In San Mateo County, California, public U.S. EPA records track 156 regulated facilities (#78 of 136 in California), including 0 (0.0%) High-Risk sites and $0 in federal penalties. Countywide due diligence also covers 1 Safe Drinking Water (SDWIS) facilities, 134 Clean Water NPDES permits, 4 FEMA Federal Disaster Declarations (4 flood/storm), USDA Soil Foundation Shrink-Swell (MODERATE signal), and EPA Zone 2 — Moderate Potential (2.0 – 4.0 pCi/L).
San Mateo County, CA 6-in-1 Flood, Soil Foundation, Tap Water & Radon Signals
🔒 Parcel-Level Soil LEP %, Water Table Depth & Flood Zone Require Street Address Scan📊 San Mateo County, CA Statistical Risk Graphs & Multi-Hazard Telemetry
SOURCE: EPA ECHO • USDA SSURGO • FEMA NRI • USGS (November 05, 2026)Municipalities in San Mateo County
ZIP Codes in San Mateo County
Top EPA Regulated Facilities in San Mateo County, CA
100% of High-Risk & penalized facilities have facility names, street names, and dockets redacted (3 Low-Risk compliant records shown as Free Previews).
| Facility Name / Hazard Type | Sector Location (Street Redacted) | Risk Tier & Score | Compliance Status | Enforcement / Unlock |
|---|---|---|---|---|
| 🔒 Locked Regulated EPA Enforcement Record #1 | 🔒 Exact Street & Parcel Redacted • MOSS BEACH, CA (ZIP 94038 Sector) | MODERATE (34/100) | No Violation Identified (0 qtrs NC) | 🔒 Active Permit Dossier • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #2 | 🔒 Exact Street & Parcel Redacted • SAN MATEO, CA (ZIP 94403 Sector) | MODERATE (34/100) | No Violation Identified (0 qtrs NC) | 🔒 Active Permit Dossier • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #3 | 🔒 Exact Street & Parcel Redacted • SOUTH SAN FRANCISCO, CA (ZIP 94080 Sector) | MODERATE (33/100) | No Violation Identified (0 qtrs NC) | 🔒 Active Permit Dossier • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #4 | 🔒 Exact Street & Parcel Redacted • SOUTH SAN FRANCISCO, CA (ZIP 94080 Sector) | MODERATE (30/100) | Resolved / Historical Non-Compliance (10 qtrs NC) | 🔒 10 Qtrs Non-Compliance • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #5 | 🔒 Exact Street & Parcel Redacted • SAN CARLOS, CA (ZIP 94070 Sector) | MODERATE (30/100) | Resolved / Historical Non-Compliance (10 qtrs NC) | 🔒 10 Qtrs Non-Compliance • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #6 | 🔒 Exact Street & Parcel Redacted • SAN CARLOS, CA (ZIP 94070 Sector) | MODERATE (30/100) | Resolved / Historical Non-Compliance (6 qtrs NC) | 🔒 6 Qtrs Non-Compliance • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #7 | 🔒 Exact Street & Parcel Redacted • SAN CARLOS, CA (ZIP 94070 Sector) | MODERATE (30/100) | Resolved / Historical Non-Compliance (10 qtrs NC) | 🔒 10 Qtrs Non-Compliance • Unlock → |
| 🔒 Locked Regulated EPA Enforcement Record #8 | 🔒 Exact Street & Parcel Redacted • REDWOOD CITY, CA (ZIP 94063 Sector) | MODERATE (30/100) | Resolved / Historical Non-Compliance (10 qtrs NC) | 🔒 10 Qtrs Non-Compliance • Unlock → |
| HALF MOON BAY AIRPORT FREE PREVIEW (LOW RISK) | 9850 CABRILLO HWY, HALF MOON BAY, CA 94019 | LOW (23/100) | No Violation Identified (0 qtrs NC) | $0 |
| BAY AREA RAPID TRANSIT DALY CITY FREE PREVIEW (LOW RISK) | 255 D ST, COLMA, CA 94014 | LOW (19/100) | No Violation Identified (0 qtrs NC) | $0 |
| EVALVE INCORPORATED FREE PREVIEW (LOW RISK) | 3885 BOHANNON DR, MENLO PARK, CA 94025 | LOW (18/100) | No Violation Identified (0 qtrs NC) | $0 |
| PACIFICA CALERA CREEK WRF FREE PREVIEW (LOW RISK) | 170 SANTA MARIA AVE, PACIFICA, CA 94044 | LOW (18/100) | No Violation Identified (0 qtrs NC) | $0 |
Frequently Asked Questions — San Mateo County, California Environmental Due Diligence
How many EPA-regulated environmental sites are in San Mateo County County, California?
Public U.S. EPA records track 156 regulated facilities in San Mateo County County, California (ranking #78 of 136 jurisdictions in CA). Of those, 0 (0.0%) are classified in the High-Risk tier due to significant enforcement or chemical release history, and 0 (0.0%) have active non-compliance quarters.
Which ZIP codes and cities in San Mateo County County have the highest regulated facility density?
Within San Mateo County County, the highest concentrations of EPA-tracked facilities are located in local postal sectors, spanning municipal corridors including Pescadero (61 sites), Redwood (1 sites).
How many hazardous waste (RCRA) and toxic release (TRI) handlers operate in San Mateo County County?
Across San Mateo County County, 19 facilities (12.2% of regulated sites) are registered Resource Conservation and Recovery Act (RCRA) hazardous waste generators or handlers, and 0 industrial sites report toxic chemical releases to the EPA Toxics Release Inventory (TRI).
What is the EPA Radon Zone classification for San Mateo County County, CA?
Geologic indoor air screening places San Mateo County County in EPA Zone 2 — Moderate Potential (2.0 – 4.0 pCi/L). Counties in EPA Radon Zone 2 have a predicted average indoor radon level between 2.0 and 4.0 pCi/L. Testing basement or ground-floor living areas is recommended during home inspection.
How many drinking water systems (SDWIS), impaired water bodies, and FEMA flood disasters are recorded in San Mateo County County, CA?
Federal records track 1 Safe Drinking Water (SDWIS) facilities, 134 Clean Water Act NPDES permits, and 14 impaired water dischargers in San Mateo County County, alongside 4 historical FEMA federal disaster declarations (4 flood/storm events).
Does San Mateo County, CA have expansive clay soil or foundation risk?
USDA regional soil engineering screening for San Mateo County indicates a MODERATE shrink-swell risk signal and steel pipe corrosivity rated Low. Run a street address scan to unlock the exact parcel soil series, LEP %, and water table depth.