Tapcensus

Water quality for ZIP code 94576

ZIP 94576 covers Deer Park in Napa County, California, one of 10 ZIP codes in the county. 188 active public water systems serve the county; 56 had an EPA violation in the past three years.

Most likely your provider

Howell Mountain Mutual Water Company CA2810001 · Community water system · Surface water
Serves 1,244 people Rules violated, past 3 years 0 Distance 1.5 mi

Your location is within the outer bounds of this system's EPA service area.

View system details EPA facility report

Other community water systems in Napa County

27 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Adventist Health St. Helena Hospital
 617 0 0.5 mi
Linda Vista Mutual Water CO
 90 0 1.1 mi
LA Tierra Heights Mutual
 67 2 1.2 mi
Vailima Estates Mutual Water
 25 0 1.4 mi
Linda Falls Terrace Mutual
 35 0 1.6 mi
Pacific Union College
 758 0 2.6 mi
Tucker Acres Mutual Water Co.
 200 1 2.9 mi
St. Helena, City of
St. Helena		 5,386 2 3.2 mi
Calistoga Farm Worker Center
 67 0 3.2 mi
River Ranch Farm Worker Center
 66 0 3.9 mi
Calistoga, City of
Calistoga		 5,610 2 6.6 mi
Berryessa Pines Water System
 261 2 11.4 mi
Berryessa Estates (lbrid)
 474 0 11.5 mi
Town of Yountville
 2,785 0 12.2 mi
Veterans Home of California
 1,000 1 12.3 mi
Mondavi Farm Worker Center
 66 0 13.4 mi
Spanish Flat Water District
 92 2 13.6 mi
R Ranch at the Lake
 20 2 14.0 mi
Hess Winery
 100 2 15.5 mi
Berryessa Highlands
 715 1 15.8 mi
Capell Valley Estates
 208 2 16.7 mi
Circle Oaks Water District
 500 0 17.2 mi
Napa, City of
Napa		 84,804 0 19.4 mi
Napa River Ranch
 70 5 24.0 mi
Milton Road Water Company
 39 1 25.0 mi
All 28 community water systems in Napa County
Non-community systems in Napa County (160: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Hunnicutt Winery
 35 0 0
Rombauer Vineyards
 50 0 0
Titus Winery
 64 0 0
Duckhorn Vineyards
 25 0 0
Ehlers Estate
 42 0 0
Mending Wall Winery
 37 0 0
Trinchero Winery
 263 0 0
Wine Country Inn
 60 1 1
Cal Fire Sonoma-Lake-Napa Unit HQ
 65 0 0
St. Helena Purlieu LLC
 25 0 0
Markham Vineyards
 38 0 0
Cairdean Winery
 30 1 0
Davis Estates
 84 0 0
Napa Valley Reserve Water System
 49 1 0
Beringer Vineyards
 300 0 0
Csp Bale Grist Mill State Historic Par
 185 0 0
Frank Family Vineyards
 25 0 0
O'shaughnessy Winery
 31 0 0
Larkmead Vineyards
 31 0 0
Fantesca Winery
 41 0 0
Howell Mountain School
 100 1 1
Pcsh, LLC
 25 0 0
Rancho la Jota
 40 0 0
Outpost Wines
 30 0 0
Lmr Main Street Partners LLC
 26 0 0
Schramsberg Winery
 65 0 0
Phelps Vineyards
 56 0 0
Castello DI Amorosa
 98 1 1
Robert Keenan Winery
 48 0 0
Sutter Home Winery
 244 0 0
Csp-Bothe-Napa Valley State Park
 586 0 0
Sterling Vineyards
 500 0 0
Clos Pegase Winery
 45 1 1
Twomey Cellars
 43 0 0
V. Sattui Winery
 45 2 1
Behrens Family Winery
 39 0 0
Wheeler Farms Winery
 43 0 0
Milat Winery
 128 0 0
Joseph Cellars Winery
 32 0 0
The Ranch Winery
 200 1 1
William Hill Winery
 25 1 0
Maxville Lake Winery
 36 0 0
Del Dotto Winery
 27 0 0
Cathiard Family Estate Winery
 75 0 0
Raymond Vineyard & Cellar
 90 1 1
Rutherford Hill Mutual Water
 232 0 0
Whitehall Lane Winery
 45 0 0
Napa County Schools: Pope Valley
 100 0 0
Quintessa Winery Water System
St. Helena 		33 0 0
Rutherford Hill Winery
 30 2 1
All non-community systems
About this data

Water systems are matched to Napa County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau place files.

ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.