Tapcensus

Water quality in Antioch, California

Antioch is in Contra Costa County. 84 active public water systems serve the county; 21 had an EPA violation in the past three years.

Most likely your provider

City of Antioch CA0710001 · Community water system · Surface water · Antioch
Serves 116,781 people Rules violated, past 3 years 0 Last sanitary survey Jan 17, 2024 Distance under 0.1 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
Randall-Bold Water Treatment Plant
 1 0 3.3 mi
Ccwd/brentwood Wtp
 0 0 3.4 mi
Casa Medanos Water System
 45 1 3.7 mi
Brentwood
Brentwood		 64,513 0 5.2 mi
Big Oak Mobile Home Park Water
 156 0 5.4 mi
Diablo Water District
 47,158 0 5.6 mi
Contra Costa Water District
 210,500 0 5.7 mi
Clayton Palms Water
 549 1 5.9 mi
City of Pittsburg
Pittsburg		 62,500 0 6.1 mi
Knightsen Community Water System
 73 0 7.2 mi
Riverview Mobile Home Park
 126 1 7.5 mi
Bella Vista Water Sys
 93 3 7.6 mi
Colonia Santa Maria
 32 2 7.9 mi
Angler S Ranch #3
 60 1 8.1 mi
Dutch Slough Water Works
 49 1 8.2 mi
Anglers Subdivision 4
 99 1 8.4 mi
Bethel Island Mutual Water CO
 123 1 8.9 mi
Farrar Park Property Owners
 140 0 8.9 mi
Marina Mobile Manor
 75 0 9.0 mi
Sandmound Mutual
 100 2 9.2 mi
Willow Park Marina
 380 1 9.2 mi
Delta Mutual Water Company
 333 1 9.3 mi
Sandy Point Mobile Home Park
 67 2 9.3 mi
Oakley Mutual Water Company
 170 2 9.4 mi
Golden State Water Company Bay Point
 23,765 0 9.4 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
Bridgehead Cafe
 75 0 0
Ebrpd Black Diamond Mines
 74 0 0
Bethel Missionary Baptist
 54 0 0
Gas N Save
 120 0 0
Concord MT Diablo Trailride Assoc.
 120 0 0
Knightsen Elementary School
 350 0 0
New Life Marina
 80 0 0
Delta Sportsman
 150 0 0
Bethel Market
 100 0 0
Sunset Marina
 30 0 0
Delta Bar and Grill
 100 0 0
Ebrpd Round Valley Water System
 82 0 0
Bay Standards
 41 1 1
Bethel Baptist Church
 75 0 0
Willowest Marina WS
 35 0 0
Bethel Harbor
 45 0 0
McAvoy Yacht Harbor
 55 0 0
Ebrpd Bay Point Regional Shoreline
Pittsburg 		105 0 0
Tess Farm Market
Brentwood 		25 0 0
Mount Diablo State Park
 364 0 0
Brentwood Marina
 30 0 0
Country Junction Deli
 200 0 0
Byron Roadhouse
 25 0 0
Sugar Barge Marina
 150 0 0
Los Vaqueros Interpretive Center
 30 0 0
Ebrpd Morgan Territory
 57 0 0
Excelsior Middle School
 600 0 0
Byron United Methodist
 50 0 0
Marin Food Specialties
 25 0 0
Holland Riverside Marina
 45 0 0
Willow Pass Bussiness Park Water System
 60 1 1
Byron Corners INC
 205 0 0
Los Vaqueros Marina Bldg
 180 0 0
Cruiser Haven Marina
 75 0 0
Old Borges Ranch Water Sys
 75 0 0
Byron Inn
 60 0 0
Byron Airport
 35 0 0
All Star Academy of Danville
 30 0 0
Dwr Delta Field Division Banks PP
 180 0 0
Wildwood Acres Resort
 28 0 0
Ebrpd Little Hills
 66 0 0
Ebrpd Old Briones Regional Park
 47 0 0
Canyon School
 80 1 1
Ebrpd Alhambra
 115 0 0
Wahl Family Water System
 65 0 0
About this data

Water systems are matched to Contra Costa County, nearest to Antioch 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.

Town locations and ZIP code areas come from U.S. Census Bureau 2020 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.