Tapcensus

California

Santa Clara County drinking water quality

119 active public water systems serve 2,074,486 people in Santa Clara County. 78 are compliant, 41 had at least one EPA violation in the past three years, 0 are designated serious violators, and 11 carry a health flag.

Active systems 119 73 community systems
People served 2.1M by public water systems
Systems with violations 41 34% of active systems, past 3 years
Serious violators 0 11 systems carry a health flag

Needs attention

O'connor Hospital CA4300808 · Non-Transient non-community system · Serves 2,500 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Monterey Mushrooms CA4300941 · Non-Transient non-community system · Serves 361 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Casa de Fruta Water System CA4300611 · Community water system · Serves 250 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Lake Canyon Mutual Water Company CA4300522 · Community water system · Serves 156 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Roseview Heights Mutual Water Company CA4300562 · Community water system · Serves 148 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Raineri Mutual Water Company CA4300520 · Community water system · Serves 145 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Kennon Water Company CA4300521 · Community water system · Serves 142 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Brush and Old Well Mutual Water Company CA4300978 · Community water system · Serves 70 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Los Ranchos de Uvas Water Company CA4300637 · Community water system · Serves 58 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Green Acres Mutual Water CA4300573 · Community water system · Serves 53 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

1 more systems with a serious violator or health flag designation are in the lists below.

Community water systems

73 systems, largest first
SystemServesStatusRules violated, 3 yrUnresolved
San Jose Water
 1,039,920 0 0
City of Sunnyvale
Sunnyvale 		157,566 5 0
City of Santa Clara
Santa Clara 		134,587 0 0
Great Oaks WC INC
 112,582 0 0
City of San Jose Evg/edv/coy
San Jose 		99,783 0 0
City of Milpitas
Milpitas 		81,915 1 0
City of Mountain View
Mountain View 		81,340 0 0
City of Palo Alto
Palo Alto 		67,658 0 0
Cwsc los Altos Suburban
 63,559 0 0
City of Gilroy
Gilroy 		59,426 0 0
City of San Jose Nsj/alviso
San Jose 		48,082 0 0
City of Morgan Hill
Morgan Hill 		47,374 0 0
Stanford University
 23,817 0 0
City of Cupertino
Cupertino 		16,336 0 0
Purissima Hills Water District
 6,252 1 0
Nasa Ames Research Center
 1,200 0 0
Cal AM West San Martin
 1,079 0 0
San Martin County Water District
 627 0 0
Coyote Valley RV Resort
 500 0 0
Camp Saratoga
 450 0 0
Lick Observatory-Ucsc
 369 0 0
Chemeketa Park Mutual Water Company
 346 1 0
Aldercroft Heights County Water District
 338 0 0
Twin Valley INC
 317 1 0
New Avenue Mutual Water Company
 305 0 0
Lupin Lodge
 300 2 1
Mt. Pleasant Water Users Association
 300 0 0
Saratoga Heights Mutual Water Company
 258 0 0
Casa de Fruta Water System
 250 1 1
Parkway Lakes RV Park
 250 1 0
Happy Acres Mwc
 220 0 0
Melody Woods Water Company
 168 3 0
Mt. Eden Mutual Water Company
 165 1 0
Lake Canyon Mutual Water Company
 156 1 1
Roseview Heights Mutual Water Company
 148 1 1
Raineri Mutual Water Company
 145 1 1
San Martin Foothills Water Company
 145 0 0
Kennon Water Company
 142 1 1
Three Springs Ranch Mutual Water Company
 110 0 0
Mecchi Water Company
 104 1 1
Oak Dell Park
 104 0 0
Rancho Robles Mutual Water Company
 103 0 0
Green Mountain Water Company
 80 1 0
Vista Grande Water Users Association
 79 0 0
Brush and Old Well Mutual Water Company
 70 1 1
Santa Teresa Meadows Water Company
 68 0 0
Golden Heights Mutual Water Company
 66 0 0
Burchell Road Water Association
 65 0 0
Spring Valley Heights Association INC
 65 0 0
Uvas Pines RV Park
 65 0 0
Non-community systems (46: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Gavilan Joint Community College District
 5,400 0 0
Santa Clara Valley Medical Center
 3,000 3 2
O'connor Hospital
 2,500 2 1
Western Digital Technologies, Inc.
 2,439 0 0
EL Camino Hospital
 2,000 0 0
Csp Henry W. Coe State Park
 1,205 0 0
Christopher Ranch L.l.c.
 735 0 0
Mt. Madonna County Park
 621 0 0
Loma Prieta Jusd-Loma Prieta School
 542 0 0
Uvas Canyon County Park
 512 0 0
Gilroy Usd-Rucker School
 510 0 0
Sanborn-Skyline County Park
 414 0 0
Monterey Mushrooms
 361 1 1
Joseph Grant County Park
 322 1 0
Walden West
 273 0 0
Willow Heights Mansion
 269 0 0
Nestldown Ranch
 265 0 0
Field Sports Park/coyote Ranch
 258 0 0
Coyote Lake County Park
 216 1 0
Calero County Park
 210 0 0
Metcalf Motorcycle County Park
 210 0 0
Mt. Hamilton Grandview Restaurant
 181 0 0
Saratoga Springs, Inc.
 180 0 0
Pacific Point Christian School
 165 0 0
Chitactac-Adams County Park
 156 0 0
George Chiala Farms INC
 150 0 0
Lakeside Sd-Lakeside School
 127 1 0
Sveadal Water System
 111 0 0
Coyote Creek Golf Club
 101 0 0
Z Best Products
 90 0 0
Henry W Coe State Park Dowdy Ranch
 65 0 0
Newby Island Landfill, Republic Services
 65 0 0
Morgan Hill Usd-Machado School
 60 0 0
Economy Inn
 52 1 0
Cinnabar Hills Golf Club
 50 1 1
Hkn LLC
 50 1 1
The Rainbow Junction Water System
 50 2 0
Learning Services Corp.
 48 0 0
Reforestation Technologies International
 34 1 1
VO UU Buddhist Meditation Association
 33 0 0
San Martin Lions Club
 30 0 0
Coyote Valley Sporting Clays
 27 1 1
Alma Latter-Day Saints Church
 25 2 1
Fortino Winery
 25 0 0
Garlic World
 25 1 0
Scc Animal Shelter/airport
 25 0 0
Inactive systems (203, no longer operating or reporting)

Kept for the record and excluded from the county totals above. Browse inactive systems.

About this data

Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.

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.