Sierra County, California
7 ZIP codes · Avg score 75/100 · Grade B · Updated 2026-07-19
ZipCheckup grade for Sierra: B.
This ZIP looks solid, with a few items worth a quick check.
Recent water monitoring in Sierra County shows 7 ZIP codes with consistently safe results.
How Sierra County Compares
How Sierra County Compares
Sierra County scores 2 points above the California state average (73/100) and 7 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-07-19
ZIP Code Risk Map
Water Quality Map: Sierra County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 15.5 (asthma 10.6%, diabetes 15.3%)
Estimated additional annual cost per homeowner: $1,903, driven primarily by wildfire
Infrastructure: 0.384% avg pipe failure probability, 57% of ZIPs at high risk
62.3% of homes built before 1978 (lead paint era)
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,903
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
1,881 housing units in Sierra County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Sierra County
Remediation costs are relatively manageable for most homeowners in Sierra County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Sierra County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Sierra County
7 community water systems serving Sierra County.
- B
- D
- B
- B
- B
- B
Show all 7 water systems
- B
Systems with the most violations in Sierra County
3 water systems with recorded EPA violations.
- D
- B
- B
All ZIP Codes in Sierra County
7 ZIP codes tracked in Sierra County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 95910 | Alleghany | 83 | B | 0 | — |
| 2 | 96125 | Sierra City | 83 | B | 1 | $377K |
| 3 | 96126 | Sierraville | 83 | B | 0 | $796K |
| 4 | 95936 | Downieville | 78 | B | 4 (2 health) | — |
| 5 | 96124 | Calpine | 72 | B | 0 | $688K |
| 6 | 96118 | Loyalton | 70 | B | 1 | $263K |
| 7 | 95944 | Goodyears Bar | 53 | D | 0 | — |
Recommended Buyer Guides for Sierra County
If FEMA records flag flood-top-risk status or EPA samples show PFAS exceedances, the matching logic lifts emergency-water and PFAS-rated filtration into the recommendations - federal data drives the order, not retailer arrangements.
- Best Lead Paint Test Kits — 62.3% of homes built before 1978
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Deep Dive Reports
Detailed analysis for Sierra County, California
Overview
Sierra County in California covers 7 ZIP codes with an average Home Safety Score of B (75/100).
3 of 7 ZIP codes have recorded EPA violations. 2 health-based violations have been documented.
← Back to California water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.