PlainWater
Counties → California

Napa County, California

Water Systems
185
Population Served
161,964
Total Violations
2,698
566 health-based
PFAS Detected
2
of 5 tested

Violation Analysis

88.1%
Systems with Violations
14.6
Avg Violations per System
21.0%
Health-Based Violations

Water Source Types

GW
35 systems (19%)
SW
15 systems (8%)

PFAS Contamination

5
Systems Tested
2
PFAS Detected
40.0%
Detection Rate

PFAS (per- and polyfluoroalkyl substances) are persistent chemicals found in drinking water. The EPA has set enforceable limits for several PFAS compounds under UCMR5 monitoring.

Compliance Snapshot

Napa California water systems by violation status, EPA SDWIS records.

No violations on record (4) One or more violations (46)

Violation history is cumulative, many flagged systems have already returned to compliance. Detail pages show per-system context.

Water Systems

System Name Population Violations PFAS
Napa, City Of 84,804 23 Clean
American Canyon, City Of 21,437 33 Clean
Phelps Vineyards 19,412 14 -
Calistoga, City Of 5,610 32 Detected
St. Helena, City Of 5,386 23 Clean
Town of Yountville 2,787 8 Clean
Pacific Union College 1,958 9 -
Howell Mountain Mutual Water Company 1,240 92 -
Veterans Home of California 1,000 9 -
Castello Di Amorosa 833 13 -
Adventist Health - St. Helena Hospital 817 7 -
Berryessa Highlands 715 59 -
Domaine Carneros 652 8 -
Csp-Bothe-Napa Valley State Park 565 4 -
Circle Oaks Water District 500 7 -
Raymond Vineyard & Cellar 490 6 -
Berryessa Estates (Lbrid) 474 54 -
Sutter Home Winery 417 0 -
Napa Valley Country Club 400 8 -
Hillside Christian Center Water System 311 0 -
Beringer Vineyards 300 12 -
Berryessa Pines Water System 261 29 -
Meyers Water Co. 250 38 -
Hess Winery 250 15 -
Bella Union Winery 238 19 -
Rutherford Hill Mutual Water 232 10 -
Spanish Flat Water District 230 21 -
Capell Valley Estates 208 58 -
Enchanted Hills 206 15 -
Bell Wine Cellars 200 0 -
Tucker Acres Mutual Water Co. 200 35 -
Tpwc Dba the Prisoner Wine Company 200 6 -
Welcome Grange Hall 200 35 -
Putah Canyon Campground 200 39 -
Domaine Chandon 200 41 -
The Ranch Winery 200 19 -
Silver Oak Wine Cellars 188 10 -
Csp - Bale Grist Mill State Historic Par 185 5 -
Schramsberg Winery 161 17 -
Clos Pegase Winery 155 17 -
Rombauer Vineyards 150 14 -
Skyline Park 150 16 -
Nickel & Nickel Winery 148 8 -
Syar Industries 130 18 -
Milat Winery 128 5 -
Chateau Montelena Winery 125 12 -
Chimney Rock Winery 122 6 -
Lewis Cellars 119 15 -
One Hope Winery 110 3 -
Baldacci Family Vineyards 110 0 -

Other Counties in California

Los Angeles County
276 systems · 10,109,089 served · 3,972 violations
San Diego County
197 systems · 3,744,323 served · 4,832 violations
Orange County
46 systems · 3,201,893 served · 507 violations
Riverside County
201 systems · 2,839,125 served · 6,103 violations
San Bernardino County
318 systems · 2,830,626 served · 4,611 violations
Alameda County
27 systems · 2,249,634 served · 275 violations

Drinking Water Guides

Frequently Asked Questions

How many water violations are in Napa County? ▼
Napa County has 2,698 total drinking water violations across 185 water systems, of which 566 are health-based violations. 88.1% of systems have at least one violation.
How many people get water from Napa County systems? ▼
Water systems in Napa County serve approximately 161,964 people through 185 public water systems.
Has PFAS been detected in Napa County water? ▼
Of 5 water systems tested for PFAS in Napa County, 2 had PFAS detected (40.0% detection rate).
What types of water sources supply Napa County? ▼
Water systems in Napa County use GW (35 systems), SW (15 systems) as their primary water sources.
Are health-based violations serious? ▼
Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 21.0% of Napa County's violations are health-based. Not all violations indicate immediate health risk, but they require corrective action.
Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations. Not all violations indicate an immediate health risk.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.