Tapcensus

Water quality for ZIP code 94526

ZIP 94526 covers Danville, San Ramon, and Alamo in Contra Costa County, California, one of 43 ZIP codes in the county. 84 active public water systems serve the county; 21 had an EPA violation in the past three years.

Most likely your provider

Contra Costa Water District CA0710003 · Community water system · Surface water
Serves 210,500 people Rules violated, past 3 years 0 Last sanitary survey Jan 13, 2022 Distance 11.1 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 Contra Costa County

38 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Wilcox Station Ranch
 31 1 9.3 mi
Moraga Heights Mutual Water
 66 0 9.6 mi
Doubletree Ranch Water System
 66 0 11.6 mi
Clayton Palms Water
 549 1 12.1 mi
City of Martinez
Martinez		 31,015 0 14.4 mi
Golden State Water Company Bay Point
 23,765 0 14.9 mi
City of Pittsburg
Pittsburg		 62,500 0 15.0 mi
Bella Vista Water Sys
 93 3 15.2 mi
Riverview Mobile Home Park
 126 1 15.2 mi
City of Antioch
Antioch		 116,781 0 15.6 mi
Casa Medanos Water System
 45 1 15.6 mi
Brentwood
Brentwood		 64,513 0 17.0 mi
Colonia Santa Maria
 32 2 17.5 mi
Randall-Bold Water Treatment Plant
 1 0 18.0 mi
Ccwd/brentwood Wtp
 0 0 18.0 mi
Camino Mobilehome
 210 0 19.4 mi
Big Oak Mobile Home Park Water
 156 0 20.0 mi
Diablo Water District
 47,158 0 20.3 mi
Knightsen Community Water System
 73 0 20.9 mi
Town of Discovery Bay
 16,790 0 21.9 mi
Orwood Resort
 350 2 22.4 mi
Dutch Slough Water Works
 49 1 22.9 mi
Angler S Ranch #3
 60 1 23.2 mi
Anglers Subdivision 4
 99 1 23.3 mi
Oakley Mutual Water Company
 170 2 23.4 mi
All 39 community water systems in Contra Costa County
Non-community systems in Contra Costa County (45: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Ebrpd Little Hills
 66 0 0
Old Borges Ranch Water Sys
 75 0 0
Mount Diablo State Park
 364 0 0
Wildwood Acres Resort
 28 0 0
All Star Academy of Danville
 30 0 0
Concord MT Diablo Trailride Assoc.
 120 0 0
Canyon School
 80 1 1
Ebrpd Morgan Territory
 57 0 0
Ebrpd Old Briones Regional Park
 47 0 0
Ebrpd Round Valley Water System
 82 0 0
Ebrpd Black Diamond Mines
 74 0 0
Los Vaqueros Marina Bldg
 180 0 0
Willow Pass Bussiness Park Water System
 60 1 1
Ebrpd Bay Point Regional Shoreline
Pittsburg 		105 0 0
McAvoy Yacht Harbor
 55 0 0
Los Vaqueros Interpretive Center
 30 0 0
Bridgehead Cafe
 75 0 0
Bay Standards
 41 1 1
Bethel Missionary Baptist
 54 0 0
Byron United Methodist
 50 0 0
Marin Food Specialties
 25 0 0
Byron Airport
 35 0 0
Byron Corners INC
 205 0 0
Excelsior Middle School
 600 0 0
Country Junction Deli
 200 0 0
Byron Roadhouse
 25 0 0
Byron Inn
 60 0 0
Knightsen Elementary School
 350 0 0
Dwr Delta Field Division Banks PP
 180 0 0
Gas N Save
 120 0 0
Tess Farm Market
Brentwood 		25 0 0
New Life Marina
 80 0 0
Delta Sportsman
 150 0 0
Sunset Marina
 30 0 0
Bethel Market
 100 0 0
Delta Bar and Grill
 100 0 0
Bethel Baptist Church
 75 0 0
Cruiser Haven Marina
 75 0 0
Holland Riverside Marina
 45 0 0
Brentwood Marina
 30 0 0
Bethel Harbor
 45 0 0
Willowest Marina WS
 35 0 0
Sugar Barge Marina
 150 0 0
Ebrpd Alhambra
 115 0 0
Wahl Family Water System
 65 0 0
About this data

Water systems are matched to Contra Costa 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.

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.