California — all systems

California water systems A–Z

Page 7 of 11 · Mesa Del Toro Mwc → Pacific Heights. Every public water system we track in California, alphabetically. Each links to the system's measured contaminant levels against federal limits.

• Mesa Del Toro Mwc (2025)
• Mesa Dunes Mobile Home Estates (2024)
• Mesa Elementary School (2023)
• Mesa Hills Mutual Water Company (2023)
• Mesquite Mines Inc. (2024)
• Metro Air Park Water System (2025)
• Mettler County Water District (2025)
• Mettler Valley Mutual (2023)
• Meyers Water Co. (2025)
• Mhc TT Inc. (dba Pio Pico) (2023)
• Mi Wuk Heights Mwc (2025)
• Mi Wuk Village Mut Wtr Co (2023)
• Michael Lucas Water System (2023)
• Michele Mutual Water Company (2024)
• Mid Valley Ag (2024)
• Mid Valley Nut Co (2023)
• Mid-City (2023)
• Mid-peninsula Water District (2024)
• Middle Road Mutual Water Co (2025)
• Midland School (2024)
• Midway City Mutual Wc (2025)
• Midway Heights C. W. D. (2024)
• Midway Mobilehome Park (2023)
• Mil Potrero Mwc (2023)
• Milk Specialties Global (2024)
• Mill Creek M.w.c. (2025)
• Mill Creek Msc (2023)
• Millennium Pacific Greenhouses (2025)
• Millers Hill School (2025)
• Millview County Water District (2024)
• Millville Elementary School (2024)
• Milton Road Water Company (2025)
• Minarets High School (2023)
• Miner Family Winery (2025)
• Mineral County Water District (2023)
• Mineral Mountain Mutual Water (2023)
• Minturn Nut Co., Inc. (2025)
• Mira Loma High Desert Hospital (2025)
• Mira Mesa (2023)
• Mira Monte Water Co. (2025)
• Miranda C.s.d. (2025)
• Mirasol Company Water System (2025)
• Mireval Improvement Association (2025)
• Misionero Vegetables Ws (2024)
• Mission (2024)
• Mission Farm R.v. Park (2024)
• Mission Highlands Mutual Water Co. (2023)
• Mission Hills Csd (2025)
• Mission Oaks Mobile Home Park (2025)
• Mission School Ws (2024)
• Mission Springs Conference Center (2023)
• Mission Springs Wd (2023)
• Mission Valley (2023)
• Mitchell's Avenue E Mobile Home Park (2022)
• Mitchells Camp Family Assoc. (2024)
• Mitsubishi Cement Plant Cushenbury (2023)
• Mjusd Browns Valley School (2024)
• Mjusd Cordua School (2025)
• Mjusd Dobbins School (2025)
• Mjusd Foothill Intermediate School (2025)
• Mjusd Loma Rica School (2025)
• Mobile Home Estates (2025)
• Mobile Villas Trailer Park (2024)
• Modern Village Mwc (2025)
• Modesto (2024)
• Modesto, City of (2025)
• Modoc Vineyard Academy (2025)
• Mojave Pud (2024)
• Mojave Solar Project Alpha Power Plant (2025)
• Mojave Solar Project Beta Power Plant (2025)
• Mokelumne Mobile Senior Park (2024)
• Monarch Nut Company (2022)
• Mondavi Farm Worker Center (2023)
• Mono Vista Ranch Mhp (2024)
• Monroe School (2024)
• Monroe/leinberger Cntr - Waters (2024)
• Monrovia Nursery - Nursery (2024)
• Monrovia Nursery - Office (2025)
• Monrovia Nursery - Venice Hills (2024)
• Monrovia-city, Water Dept. (2024)
• Montague, City of (2025)
• Montara Water and Sanitary District — Montara, Ca (2023)
• Monte Sereno (2025)
• Monte Sereno Mutual Benefit Water (2024)
• Monte Shasta M.w.c. (2024)
• Monte Vista Christian School (2024)
• Monte Vista Farming (2025)
• Monte Vista Wd (2025)
• Montebello Land & Water Co. (2024)
• Montecito Sea Meadows (2024)
• Montecito Water Dist (2024)
• Monterey Bay Academy (2025)
• Monterey Bay Nursery Ws (2025)
• Monterey Dunes Mwa (2024)
• Monterey Mushrooms (2023)
• Monterey Mushrooms - Hall Rd (2023)
• Monterey Mushrooms - Maher Crt (2024)
• Monterey One Water (2024)
• Monterey Park Tract Csd (2024)
• Monterey Park-city, Water Dept. (2024)
• Montessori Del Mar Learning Center (2025)
• Montgomery Creek School (2024)
• Moon Valley Water System (2023)
• Moonstone Heights Mwa (2025)
• Moore Learning (formerly Sheldon Acres) (2019)
• Morada Acres Water System (2024)
• Morada Estates N Pws #46 (2024)
• Morada Estates Pws (2024)
• Morada Manor Water System (2024)
• Morada Produce (2024)
• Moraga (2024)
• Moraga Heights Mutual Water (2019)
• Morehead Park (2025)
• Moreno Valley (2024)
• Moreton Bay Professional Plaza (2024)
• Morgan Hill Usd-machado School (2025)
• Morning Star King, Llc (2025)
• Morning Star Pkg. Co.-wms. (2023)
• Morningside Mobilehome Park (2025)
• Moro Cojo Mwa (2023)
• Moro Rd Ws #09 (2024)
• Morongo Golf Course at Tukwet Cnyn (2023)
• Morro Bay Pw Dept - Water Division (2024)
• Morro Rock Mutual Water Co (2025)
• Morton's Warm Springs / Sonoma Springs (2025)
• Moss Landing Mwc (2023)
• Moss Mobile Manor (2024)
• Moulton Niguel Water District (2024)
• Mount Laguna Improvement Assn. (2024)
• Mount Madonna Center (2022)
• Mount Toro Ranchos Mwa (2025)
• Mountain Center Cafe (2025)
• Mountain Creek School (2024)
• Mountain Elementary School (2020)
• Mountain Empire High School (2024)
• Mountain Gate C.s.d. (2024)
• Mountain House School (2023)
• Mountain Meadows Mwc (2021)
• Mountain Mesa Wc (2024)
• Mountain of Attention Water (2024)
• Mountain Springs Mutual Water Company (2025)
• Mountain Valley Apts & Rvp (2025)
• Mountain Valley Child and Family Service (2023)
• Mountain View Cold Storage (2025)
• Mountain View Continuation School (2024)
• Mountain View Duplexes (2024)
• Mountain View Elementary School (2024)
• Mountain View Mhp (2025)
• Mountain View Mobile Estates, Llc (2024)
• Mountain View Trailer Court (2024)
• Mountain Village Homeowner's Assoc (2025)
• Mp Associates, Inc. (2024)
• Mp Mine Operations Llc (2024)
• Mpwd-coulterville Csa 1 (2024)
• Mt Ararat Mobile Home Park (2024)
• Mt Baldy Homeowners Assn. (2025)
• Mt. Eden Mutual Water Company (2024)
• Mt. Hermon Association, Inc. (2023)
• Mt. Konocti Mutual Water Company (2024)
• Mt. Pleasant Water Users Association (2024)
• Mt. Shasta, City of (2024)
• Muir Beach Community (2023)
• Mulberry Mhp (2024)
• Mulberry Union School (2021)
• Muller Mutual Water Company (2024)
• Mumm of Napa Valley (2024)
• Muriel Wright Residential Center (2023)
• Murphy Hill Ws #01 (2023)
• Murphy Hill Ws #02 (2024)
• Murrieta Palms Mobile Home Park (2024)
• Murrieta/hernandez Farms (2025)
• Musco Family Olive Co (2025)
• Muscoy Mwc No. 1 — San Bernardino, Ca (2023)
• Musd-new Haven School (2024)
• Musick Meadows 1 (2025)
• Musick Meadows 2 (2024)
• Mustang Mutual Water System (2025)
• Mustang Springs Mutual Water (2024)
• Mutual Water Association (2024)
• MWD - Eagle Mountain (2023)
• MWD of So Cal Gene Plant (2023)
• MWD of So Cal Iron Mountain (2023)
• Mycopia Llc (2025)
• Myers Flat M.w.s. Inc. (2023)
• Myoma Dunes Mutual Water Company (2024)
• Nacimiento Water Company (2024)
• Naf El Centro (2026)
• Napa County Schools: Pope Valley (2023)
• Napa River Ranch (2024)
• Napa Valley Country Club (2025)
• Napa, City of (2024)
• Naples (2023)
• Nas North Island & Nab Coronado (2023)
• Nasa Ames Research Center — Moffett Field, Ca (2023)
• National Cement Co.-lebec Plant (2025)
• Natividad Rd Ws #02 (2023)
• Navajo Mwc (2024)
• Naval Base Ventura County, Point Mugu — Point Mugu, Ca (2023)
• Naval Base Ventura County, Port Hueneme (2025)
• Navalair Mobile Home Park (2024)
• Navelencia School (2024)
• Ncsos, Mccourtney Rd. (2025)
• Needles, City of (2025)
• Neil's Service Center (2023)
• Nelson Industrial Park (2025)
• Nepenthe Ws (2025)
• Netto Ag Inc. (2024)
• Nevada Id - E. George, Banner Mountain (2024)
• Nevada Id - Lake of Pines — Grass Valley, Ca (2023)
• Nevada Id - Lake Wildwood (2023)
• Nevada Id - Loma Rica (2024)
• Nevada Id - North Auburn (2023)
• Nevada Id - Smartsville (2025)
• New Auberry Water Association (2022)
• New Avenue Mutual Water Company (2025)
• New Camaldoli Hermitage Ws (2023)
• New Hope Landing General Store (2024)
• New Horizons Mobile/rv Park (2024)
• New Jerusalem School (2023)
• New Legend Logistics (2025)
• New Meadows (2025)
• Newberry Elementary School (2024)
• Newby Island Landfill, Republic Services (2024)
• Newell County Water District (2025)
• Nicasio School (2023)
• Nicasio Valley Ranch Mutual (2024)
• Nice Mutual Water Company (2025)
• Nichols Farms (2023)
• Nickel & Nickel Winery (2025)
• Nipomo Comm Services Dist (2024)
• Nishi Quality Flowers, Inc. (2025)
• Nmip Fire & Water System, Llc (2023)
• Nob Hill (2024)
• Noe Valley (2024)
• Noel Heights-cal Water Service (puc) (2025)
• Noll Properties (2024)
• Norcal Water Works (2024)
• Norco, City of (2024)
• Nord Country School (2024)
• Nord Road Water Association (2025)
• Normal Heights (2023)
• Normans Nursery (2023)
• Norris Canyon Property Owners Assn (2024)
• North Beach (2024)
• North Coast County Water Dist (2025)
• North Davis Meadows (2022)
• North Edwards Wd (2025)
• North Fork Elementary School (2023)
• North Gualala Water Company (2024)
• North Hollywood (2023)
• North Kaweah Mutual Water Company (2024)
• North Kranenburg Ws (2024)
• North Lone Pine Mutual Water Company (2025)
• North Marin Water District — Novato, Ca (2023)
• North Marin Wd - Pt. Reyes (2023)
• North Muroc Mutual Water Company (2025)
• North Oaks Mutual Water Co (2024)
• North Park (2023)
• North Peak Mutual Water Company (2024)
• North Shore Estates Ws (2024)
• North Shore Mwc (2025)
• North Star Mobile Home Park (2024)
• North Tahoe Pud - Carnelian Woods (2025)
• North Tahoe Pud - Dollar Cove (2025)
• North Tahoe Pud - Main (2025)
• North Trails Mutual Water Company (2024)
• North Valley School Pws (2025)
• North Valley Services (2023)
• North Yuba Water District (2024)
• Northbay Logistics Center Fka Savemart (2023)
• Northcrest Mobile Home Park (2023)
• Northgate 880 [sws] (2025)
• Northridge (2023)
• Northrop Grumman Corp. (2023)
• Northstar at Tahoe Comstock Water System (2025)
• Northstar C.s.d. (2024)
• Northstar Csd - Martis Valley (2023)
• Northwest Pipe Company (2023)
• Northwest Prep Charter School (2024)
• Norwalk - City, Water Dept. — Norwalk, Ca (2022)
• Nps - Death Valley, Cow Creek/nevares (2025)
• Nps - Death Valley, Furnace Creek (2025)
• Nps - Death Valley, Stovepipe Wells (2025)
• Nps Ggnra (2024)
• Nps Prns - Beaches (2021)
• Nps-ash Mountain (2025)
• Nps-grant Grove — Three Rivers, Ca (2023)
• Nps-wolverton (2025)
• Nuestro School (2025)
• Nuevo Water Company (2025)
• Nvusd: Stonebridge School (2025)
• Nyack Water System (2024)
• Nyeland Acres Mutual Water Co (2024)
• O Me-nook Maintenance and Operation (2024)
• O-g Packing Co (2024)
• O'connor Hospital (2023)
• O'connor Tract Co-operative Water Co. (2025)
• O'neill Vintners & Distillers (2025)
• Oak Creek Mobile Home Park (2024)
• Oak Dell Park (2025)
• Oak Glen Domestic Water (2025)
• Oak Glen Retreat (2025)
• Oak Grove Mobile Home Park — Bell Canyon, Ca (2023)
• Oak Grove School (2024)
• Oak Haven Association (2024)
• Oak Heights W & R Co Inc (2023)
• Oak Knolls Mutual Water Company (2025)
• Oak Manor Ws (2025)
• Oak Ridge Winery, Llc (2025)
• Oak Run Elementary School (2024)
• Oak Trail Estates (2025)
• Oak Trail Ranch (2025)
• Oak Valley Acres P.o.a. (2018)
• Oak Valley School (2025)
• Oak View Union Elementary Sch (2024)
• Oakdale, City of (2025)
• Oakhurst Mobile Home Estates (2023)
• Oaklane Mobile Village, Llc. (2025)
• Oakley Mutual Water Company (2025)
• Oakmont Water System (2025)
• Oakvale Park (2025)
• Oakville Grocery Co. (2024)
• Oakwood Lake Water District-subdivision (2025)
• Oasis Date Gardens (2025)
• Oasis Investments (2023)
• Oasis Property Owners Association (2025)
• Occidental Arts & Ecology Center (2024)
• Occidental Community Services District (2023)
• Ocean Beach (2023)
• Ocean's Edge Estates (2025)
• Oceano Comm Services Dist. (2024)
• Oceanside, City of (2024)
• Ocotillo Mutual Water Co (2023)
• Ocotillo Oasis, Llc (2024)
• Odd Fellows Recreation Club (2023)
• Odiyan Buddhist Retreat Center (2022)
• Oid #22 - Williams Tract (2023)
• Oid #45 (2023)
• Oid #46 - Sunset Oaks (2023)
• Oid #51 - Sunset Oaks #10 (2023)
• Oid-oakdale Rural Water System #1 (2023)
• Oildale Mwc (2025)
• Ojai Water System — Oak View, Ca (2023)
• Okieville Highland Acres Mwc (2024)
• Oku Incorporated (2022)
• Old River Mutual Water Company (2023)
• Old Stage Rd Ws #21 (2025)
• Old Sugar Mill Winery (2022)
• Olivares Farms Water System (2024)
• Olivarez Honey Bees (2024)
• Olive Crest (2022)
• Olive Dell Ranch (2024)
• Olive Lane Mobilehome Park (2024)
• Olivehurst Public U.d. (2023)
• Olivenhain MWD (2025)
• Olivet Elementary School (2025)
• Olivet University (2025)
• Olympia Mobilodge (2023)
• Olympic Valley Mwc (2025)
• Olympic Valley Psd (2024)
• Om Scott & Sons/hyponex Corp (2023)
• Omya California, a Division of Omya Inc (2025)
• Onitsuka Brothers Ws (2025)
• Ontario (2024)
• Op Murphy & Sons Ws (2025)
• Opal Fry and Son (2023)
• Open Sky Ranch (2022)
• Ophir Elementary School Water System (2024)
• Opus One Winery (2025)
• Orange Vale Water Company (2024)
• Orchard Dale Water District (2024)
• Orchard Ln Ws #02 (2023)
• Orick C.s.d. (2023)
• Orinda (2024)
• Orland Estates Mobile H.p. (2025)
• Orland Mobile H.p. (2024)
• Orleans C.s.d. (2025)
• Orleans Mutual Water Company (2025)
• Orosi Public Utility District — Orosi, Ca (2023)
• Oroville Mobile Home Park (2023)
• Ortega Oaks Rv Park&campground (2024)
• Orwood Resort (2024)
• Otay Mesa (2023)
• Otay Water District — Spring Valley, Ca (2023)
• Outdoor Resorts Rancho Ca (2023)
• Outer Sunset (2024)
• Outlook Wa (2023)
• Outside Creek School (2025)
• Owens Peak South (2025)
• Owens Peak West (2025)
• Owens Valley Water Resources, Inc. (2023)
• Owens-brockway Glass Container Inc (2024)
• Oxnard Pallet Company (2023)
• Oxnard Water Dept (2025)
• Pacheco Elementary School (2025)
• Pacific Beach (2023)
• Pacific Bell Ue17l Water System (2021)
• Pacific Coast Energy Company (2024)
• Pacific Dunes Ranch (2023)
• Pacific Heights (2024)