California

Monterey County drinking water quality

311 active public water systems serve 494,172 people in Monterey County. 184 are compliant, 127 had at least one EPA violation in the past three years, 1 is a designated serious violator, and 48 carry a health flag.

Active systems 311 157 community systems

People served 494K by public water systems

Systems with violations 127 41% of active systems, past 3 years

Serious violators 1 48 systems carry a health flag

Needs attention

Growers Service Assn WS (ice) CA2702484 · Non-Transient non-community system · Serves 500 2 rules violated in the past three years. Unresolved: Lead and Copper Rule and Lead and Copper Rule Revisions.

Little Bear Water Company CA2710016 · Community water system · Serves 2,327 1 rule violated in the past three years. Unresolved: Ground Water Rule.

Laguna Seca Recreation WS CA2702009 · Non-Transient non-community system · Serves 1,248 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

San Ardo WD CA2700728 · Community water system · Serves 575 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

Plaskett Creek Campgrounds WS CA2702562 · Transient non-community system · Serves 501 2 rules violated in the past three years. Unresolved: Surface Water Treatment Rule.

Pond-Derosa Oaks WC CA2701553 · Community water system · Serves 216 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

Firestone Business Park WS CA2701214 · Non-Transient non-community system · Serves 154 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

Bud Antle, Llc Marina Facility WS CA2700998 · Non-Transient non-community system · Serves 151 3 rules violated in the past three years. Unresolved: Lead and Copper Rule and Lead and Copper Rule Revisions.

Assisi Mwc CA2700503 · Community water system · Serves 126 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.

San Miguel WS #01 CA2700738 · Community water system · Serves 100 2 rules violated in the past three years. Unresolved: Revised Total Coliform Rule and Lead and Copper Rule.

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

Community water systems

157 systems, largest first

System	Serves	Rules violated, 3 yr	Unresolved
Ventana Big Sur Inn WS	66	0	0
Vierra Knolls Mwc	66	1	1
Garlen Court WS	65	1	1
Hidden Views MHP WS	65	0	0
Murphy Hill WS #01	65	1	1
Pine ST WS #01	65	0	0
River RD WS #25	65	2	1
Vierra Meadows Mwc	65	0	0
Pioneer Place Mws	64	0	0
Hidden Canyon Ranch Mwc	62	0	0
Z Ranch Mwc	62	0	0
Delany WC	60	0	0
Elkhorn RD WS #04	60	0	0
North Shore Estates WS	60	0	0
Psmcsd Blackie RD WS	60	0	0
Royal Oak Place WS	60	1	1
Chetmoore Acres WA	59	0	0
Thimio Mwc	59	1	0
Tierra Meadows HOA WS	58	0	0
Woodland Heights Mwc	57	0	0
Desmond RD WS #03	56	0	0
Green Acres WA	56	0	0
Jost Post WA	56	0	0
Paradise RD WS #09	56	1	1
Cachagua Mutual WS (#4)	55	1	0
Del Monte Farms RD WS #03	55	0	0
Corda RD WS	54	3	1
Tierra Vista Mwc	54	1	1
Apricot LN WS	53	0	0
Pesante RD WS #06	50	1	1
San Juan RD WS #01	49	0	0
Baumann RD WS #01	48	0	0
Maher RD WS #05	48	1	1
Paradise RD WS #21	48	1	1
Tierra Verde Mwc	48	1	1
Foothill WA	46	1	1
Echo Valley RD WS #05	45	0	0
San Miguel WS #03	45	1	1
Sunny Acres Mws	45	1	1
Woodside WA	45	1	1
Paradise RD WS #05	42	0	0
Rancho Chaparral Mwc	42	0	0
Brandon Creek Mws	41	1	1
Berry DR WS #02	40	0	0
Calera Canyon Heights HOA	40	0	0
Royal Sierra Estates WS	36	1	0
Hitchcock RD WS #01	35	0	0
Mount Toro Ranchos Mwa	35	0	0
Outlook WA	35	0	0
Partington Mwc	35	0	0

Non-community systems (154: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

System	Serves	Rules violated, 3 yr	Unresolved
Soledad Mission WS	6,000	0	0
Caltrans Camp Roberts Rsra SB	2,560	1	0
Caltrans Camp Roberts Rsra NB	1,750	1	0
Laguna Seca Recreation WS	1,248	2	1
Csp-Andrew Molera State Reserve	1,005	2	2
San Antonio Lake Park North WS	1,002	1	0
Bud Antle, Llc-Soledad Facility WS	900	0	0
Csp-J.p. Burns Park	802	0	0
Elkhorn School WS	694	0	0
EL Camino Real WS #16	679	0	0
Prunedale School WS	655	0	0
San Antonio Lake Park South WS	653	1	0
Cdfw Elkhorn Slough Ecological Reserve	650	1	0
Echo Valley School WS	579	1	0
Plaskett Creek Campgrounds WS	501	2	1
Arroyo Seco Rec WS	500	0	0
Growers Service Assn WS (ice)	500	2	2
Chamisal WA	396	1	1
Camp Roberts California National Guard	385	0	0
Wildhorse Cafe WS	367	1	1
Manzanita Park WS	309	0	0
Old Natividad RD WS #01	300	0	0
San Antonio School District WS	300	0	0
D'arrigo Harris RD WS #10	284	0	0
Royal Oaks Park WS	251	0	0
Altman Plants WS #04 -Esp 420 (prev Cs1)	250	0	0
Washington School WS	250	0	0
Corral de Tierra Country Club WS	225	1	1
Ripplewood Resort WS	220	0	0
Holman Ranch WS	215	0	0
Big Sur Campground WS	209	0	0
Cypress Community Church WS	207	0	0
Gonzales Gas Station WS	204	1	0
Csp-Limekiln	202	0	0
Moss Landing Mwc	200	0	0
Prunetree Shopping Center WS	200	0	0
Marina Landfill WS	180	1	0
Matsui Nursery WS	165	0	0
Carmel by the River RV Park WS	164	0	0
Esperanza RD WS	160	0	0
Firestone Business Park WS	154	2	1
Bud Antle, Llc Marina Facility WS	151	3	2
Prunedale Shopping Center WS	150	1	1
Coast Gallery WS	125	0	0
Big Sur Bazaar WS	119	0	0
Altman Plants WS #03 Espinosa 303	110	0	0
Scheid Vineyard WS	105	0	0
Riverside Campground WS	102	0	0
Bradley Union School WS	100	2	1
Hitchcock RD WS #02	100	0	0
Mission School WS	100	0	0
Watsonville Produce INC	98	0	0
Flrish Farms WS	97	1	0
San Clemente Rancho WS	96	0	0
Vierra Canyon WS #29	96	1	0
Monterey One Water	93	0	0
Prunedale Plaza WS	90	0	0
Driscoll Strawberry WS	85	0	0
Captain Cooper School WS	82	1	0
Floricultura Pacific WS	82	1	1
Jacks Ranch-Reservation Road WS	82	1	0
Free Will Baptist Church WS	80	0	0
Pajaro Valley Greenhouse WS	80	2	1
Aera Energy LLC WS	79	0	0
Carmel Valley Tennis Camp WS	73	0	0
Foster RD WS #02	72	0	0
Growers Company INC WS	71	0	0
Alvarez Brothers WS	70	0	0
Central Bay High School WS	70	0	0
Estancia Winery WS	70	0	0
Golden State Vintners WS	70	0	0
Loma Vista Inn WS	70	0	0
Hartnell RD WS #1	69	0	0
Rod McLellan Botanicals WS	69	1	0
Calvary Church INC WS	68	1	1
Stonepine Resort WS	66	0	0
Capurro & Son WS	64	1	1
Misionero Vegetables WS	61	0	0
Growers Transplanting WS	58	1	1
Saddle Mountain WS	58	0	0
Glen Oaks WS #01	57	0	0
Graves School WS	56	1	1
Spca WS	55	1	1
Oak Park WS	53	0	0
Church of the Good Shepherd WS	50	0	0
Dolan RD Water System #2	50	1	1
Gorda WS	50	0	0
Hilltop Mwa	50	0	0
Lucia WS	50	0	0
Onitsuka Brothers WS	50	0	0
Top Industries WS	50	1	0
Monterey Mushrooms Maher Crt	49	1	1
River RD WS #26	49	0	0
Faith and Family Farms WS	48	2	1
Camphora Station WS	45	0	0
Kendall-Jackson Winery WS	45	0	0
Spreckels LN WS #03	45	1	1
Alba WS	40	0	0
Cypress Center WS	40	0	0
Emerald Valley-Zabala WS	40	1	1

All 154 in the systems table

Inactive systems (373, 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.

Monterey County drinking water quality

Needs attention

Community water systems

Compliant

Violations in the past 3 years

Serious violator

Health flag

Inactive system