Nevada County, California
14 ZIP codes · Avg score 68/100 · Grade C · Updated 2026-06-03
Water monitoring across Nevada County's 14 ZIP codes paints a mid-range picture — solid compliance in some zones, documented concerns in others; most violations on record are concentrated in specific prior years rather than spread evenly across the full compliance history, and the overall county grade has held steady in the middle tier without major shifts in either direction.
How Nevada County Compares
How Nevada County Compares
Nevada County scores 5 points below the California state average (73/100) and 0 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Nevada County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.7 (asthma 10.2%, diabetes 11.4%)
Estimated additional annual cost per homeowner: $1,928, driven primarily by wildfire
Infrastructure: 0.345% avg pipe failure probability, 27% of ZIPs at high risk
63.8% of homes built before 1978 (lead paint era)
Violation History (2023–2024)
→ Stable trendEPA violation counts by year across Nevada County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 2 violations. Past 5 years: 4 total (4 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
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: $1,928
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
55,355 housing units in Nevada 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 Nevada County
Remediation costs are relatively manageable for most homeowners in Nevada 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 Nevada County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Nevada County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | NEVADA ID - E. GEORGE, BANNER MOUNTAIN | 17,154 | 6 |
| 2 | Nevada Id - Lake Wildwood | 9,108 | 6 |
| 3 | Creekside Village | 300 | 3 |
| 4 | Sierra Estates Mutual Water Company | 100 | 3 |
| 5 | Nevada Id - Loma Rica | 14,072 | 2 |
23 total water systems serve Nevada County.
All ZIP Codes in Nevada County
14 ZIP codes tracked in Nevada County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 95949 | Grass Valley | 83 | B | 1 | $552K |
| 2 | 96111 | Floriston | 83 | B | 1 | — |
| 3 | 96160 | Truckee | 83 | B | 0 | — |
| 4 | 95959 | Nevada City | 82 | B | 1 (1 health) | $603K |
| 5 | 95946 | Penn Valley | 79 | B | 3 (1 health) | $534K |
| 6 | 95945 | Grass Valley | 78 | B | 1 | $497K |
| 7 | 96161 | Truckee | 78 | B | 0 | $922K |
| 8 | 95714 | Dutch Flat | 63 | C | 0 | $472K |
| 9 | 95724 | Norden | 59 | C | 0 | — |
| 10 | 95986 | Washington | 54 | D | 2 (1 health) | — |
| 11 | 95924 | Cedar Ridge | 53 | D | 0 | — |
| 12 | 95975 | Rough And Ready | 53 | D | 0 | $582K |
| 13 | 95977 | Smartsville | 53 | D | 0 | $441K |
| 14 | 95960 | North San Juan | 52 | D | 0 | $283K |
Recommended Buyer Guides for Nevada County
Four sources — EPA, NSF, FEMA, CDC — drive the match.
- Best Water Filters for Lead — Lead above EPA action level in 1 ZIP code
- Best Lead Paint Test Kits — 63.8% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Deep Dive Reports
Detailed analysis for Nevada County, California
Overview
Nevada County in California covers 14 ZIP codes with an average Home Safety Score of C (68/100).
6 of 14 ZIP codes have recorded EPA violations. 3 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.