Mendocino County, California
29 ZIP codes · Avg score 74/100 · Grade B · Updated 2026-06-04
Water utilities serving Mendocino County's 29 ZIP codes have built a consistent compliance record — the county's above-average grade reflects years of data showing low violation rates and no systemic health concerns.
How Mendocino County Compares
How Mendocino County Compares
Mendocino County scores 1 points above the California state average (73/100) and 6 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Mendocino County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.4 (asthma 10.5%, diabetes 13.3%)
Estimated additional annual cost per homeowner: $1,441, driven primarily by wildfire
Infrastructure: 0.358% avg pipe failure probability, 18% of ZIPs at high risk
64.8% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Mendocino County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 9 violations. Past 5 years: 22 total (22 health-based). Health-based violations are declining versus the prior 2-year window.
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: $1,441
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
47,705 housing units in Mendocino 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 Mendocino County
Remediation costs are relatively manageable for most homeowners in Mendocino 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 Mendocino 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 Mendocino County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Millview County Water District | 5,500 | 11 |
| 2 | Rogina Water Company Inc. | 2,554 | 10 |
| 3 | Redwood Valley County Water District | 5,200 | 7 |
| 4 | City of 10,000 Buddhas | 400 | 7 |
| 5 | Yokayo Tribe of Indians | 75 | 7 |
35 total water systems serve Mendocino County.
All ZIP Codes in Mendocino County
29 ZIP codes tracked in Mendocino County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 95445 | Gualala | 95 | A | 0 | $665K |
| 2 | 95470 | Redwood Valley | 89 | A | 4 | $533K |
| 3 | 95410 | Albion | 88 | A | 0 | $706K |
| 4 | 95437 | Fort Bragg | 88 | A | 4 (2 health) | $541K |
| 5 | 95488 | Westport | 88 | A | 0 | — |
| 6 | 95468 | Point Arena | 86 | A | 1 | $451K |
| 7 | 95460 | Mendocino | 85 | A | 5 (5 health) | $666K |
| 8 | 95432 | Elk | 83 | B | 2 (1 health) | $728K |
| 9 | 95459 | Manchester | 83 | B | 2 (1 health) | $643K |
| 10 | 95481 | Talmage | 81 | B | 7 (3 health) | — |
| 11 | 95482 | Ukiah | 78 | B | 3 (1 health) | $473K |
| 12 | 95428 | Covelo | 73 | B | 0 | $376K |
| 13 | 95456 | Little River | 73 | B | 0 | $490K |
| 14 | 95463 | Navarro | 73 | B | 0 | — |
| 15 | 95466 | Philo | 73 | B | 0 | $699K |
| 16 | 95469 | Potter Valley | 73 | B | 0 | $594K |
| 17 | 95415 | Boonville | 70 | B | 0 | $638K |
| 18 | 95017 | Davenport | 66 | C | 0 | $993K |
| 19 | 95417 | Branscomb | 66 | C | 0 | — |
| 20 | 95418 | Calpella | 66 | C | 0 | — |
| 21 | 95420 | Caspar | 66 | C | 0 | $1103K |
| 22 | 95427 | Comptche | 66 | C | 0 | $868K |
| 23 | 95429 | Dos Rios | 66 | C | 0 | $377K |
| 24 | 95454 | Laytonville | 66 | C | 0 | $385K |
| 25 | 95494 | Yorkville | 66 | C | 0 | — |
| 26 | 95497 | The Sea Ranch | 66 | C | 0 | $1198K |
| 27 | 95585 | Leggett | 66 | C | 0 | $374K |
| 28 | 95010 | Capitola | 60 | C | 0 | $782K |
| 29 | 95490 | Willits | 59 | C | 4 | $384K |
Recommended Buyer Guides for Mendocino County
Independent picks. EPA-grounded. Matched here.
- Best Water Filters for Lead — Lead above EPA action level in 3 ZIP codes
- Best Lead Paint Test Kits — 64.8% 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 Mendocino County, California
Overview
Mendocino County in California covers 29 ZIP codes with an average Home Safety Score of B (74/100).
9 of 29 ZIP codes have recorded EPA violations. 13 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.