Tap Truth EPA drinking water records, in plain English

County drinking water records

Napa County, CA drinking water systems

28 community water systems serve Napa County, CA, reporting 128,683 people served in all.

16 of them (57%) had at least one health-based violation in the last 10 years. 12 systems still have one unresolved.

15 rely mainly on groundwater and 13 on surface water, counting water bought from other systems.

23 systems filed a lead service line inventory listing 0 lead lines, 63 galvanized lines that must be replaced and 4,021 lines of unknown material.

Community water systems
28
People served, sum of each system's own figure
128,683
Systems with a health-based violation, last 10 years
16
Systems with one unresolved
12
Lead service lines in inventories
0

Water systems serving Napa County

28 systems

People served is each system's own figure for its whole service area. Violation counts cover the last 10 years of EPA records.

System Serves People served Main source Health-based violations, 10 years Unresolved Lead lines
City of Napa Napa, Silverado Resort and 2 more and land outside them 84,804 Surface water 0 0 0
City of American Canyon American Canyon and land outside it 21,437 Surface water 9 0 0
City of Calistoga Calistoga 5,610 Surface water 7 1 0
City of St. Helena St. Helena 5,386 Surface water 11 1 0
Town of Yountville Yountville 2,787 Purchased surface water 0 0 0
Pacific Union College Angwin 1,958 Groundwater 0 0 0
Howell Mountain Mutual Water Company Angwin and Deer Park 1,240 Surface water 4 0 0
Veterans Home of California Yountville 1,000 Surface water 1 2 No inventory
Adventist Health - St. Helena Hospital Deer Park 817 Groundwater 0 0 0
Berryessa Highlands Outside cities and towns 715 Surface water 16 0 0
Circle Oaks Water District Outside cities and towns 500 Surface water 0 0 0
Berryessa Estates (Lbrid) Outside cities and towns 474 Surface water 4 0 0
Berryessa Pines Water System Outside cities and towns 261 Surface water 1 2 0
Meyers Water Co. Outside cities and towns 250 Groundwater 1 0 0
Hess Winery Outside cities and towns 250 Groundwater 1 3 No inventory
Spanish Flat Water District Outside cities and towns 230 Surface water 1 2 0
Capell Valley Estates Moskowite Corner 208 Surface water 1 3 0
Tucker Acres Mutual Water Co. Outside cities and towns 200 Groundwater 0 1 0
Linda Vista Mutual Water Co Deer Park 90 Groundwater 0 0 0
Napa River Ranch Outside cities and towns 70 Groundwater 2 2 No inventory
La Tierra Heights Mutual Angwin 67 Groundwater 1 1 No inventory
River Ranch Farm Worker Center Outside cities and towns 66 Groundwater 0 0 0
Mondavi Farm Worker Center Outside cities and towns 66 Groundwater 0 0 0
Calistoga Farm Worker Center Outside cities and towns 65 Groundwater 0 0 0
Milton Road Water Company Outside cities and towns 44 Groundwater 1 2 0
Linda Falls Terrace Mutual Outside cities and towns 35 Groundwater 0 0 0
R Ranch at the Lake Outside cities and towns 28 Groundwater 1 2 No inventory
Vailima Estates Mutual Water Deer Park 25 Groundwater 0 0 0

Cities and towns in Napa County

11 places

Back to California

Counties come from the counties EPA lists each system serving, matched to 2024 Census counties; where EPA lists none, from the county coded in the system's ID, its service area map, or its mailing address. A county holding at least a fifth of a system's service area map is added when at least a fifth of that map lies in those counties. Towns are the ones EPA lists and the Census places such a map covers, always inside those counties. In New England, where EPA's town names a whole Town, it is not matched to the village of the same name. A system is not listed in a county holding less than a fifth of its map, or in a county or town its map reaches when the map lies mostly outside the counties EPA lists, so a page can leave out a system that serves part of the area. Methodology and limitations