Merced County, California — public water systems
At a glance
120 active public water systems are filed under Merced County, California in EPA's SDWIS records, together reporting 267,324 people served. The largest is City of Merced, which reports serving 93,692 people. 22 are community water systems serving people where they live; the other 98 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
120
Population served
267.3K
Community systems
22
Groundwater share
90.8%
How does Merced County compare with other California counties?
Merced County has the 21st-most active public water systems among the 201 counties listed for active California systems in EPA records; among the 72 with 3 or more systems, the median has 73. Its systems report 267,324 people served in total, the 27th-largest county figure in the state and 0.6% of the statewide total. The average system here reports serving 2,228 people, about 61% below the California average of 5,706. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.
Where does Merced County's drinking water come from?
By primary water source, Merced County's active systems draw on groundwater (109, 91%), surface water (10, 8.3%) and purchased surface water (1, 0.8%). Overall, 91% rely mainly on groundwater (including purchased groundwater) and 9.2% on surface water, compared with 85% and 15% across California. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Merced, draws primarily on groundwater.
What kinds of water systems operate in Merced County?
Merced County's active systems break down as 22 community systems (18%), 56 non-transient non-community systems (47%) and 42 transient non-community systems (35%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (67%), local government (25%), state government (6.7%) and federal government (1.7%).
The 50 largest water systems in Merced County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | City of Merced | Merced | 93,692 | Community | Groundwater |
| 2 | City of Los Banos | Merced | 47,419 | Community | Groundwater |
| 3 | City of Atwater | Merced | 29,479 | Community | Groundwater |
| 4 | City of Livingston | Merced | 14,894 | Community | Groundwater |
| 5 | Winton Water & Sanitary Dist | Merced | 9,745 | Community | Groundwater |
| 6 | Delhi Cwd | Merced | 7,784 | Community | Groundwater |
| 7 | City of Dos Palos | Merced | 7,452 | Community | Surface water |
| 8 | Cal Trans Erreca Rest Area | Merced | 6,150 | Transient non-community | Surface water |
| 9 | City of Gustine | Merced | 6,110 | Community | Groundwater |
| 10 | Cal Am - Meadowbrook | Merced | 5,656 | Community | Groundwater |
| 11 | Hilmar County Water District | Merced | 5,504 | Community | Groundwater |
| 12 | Planada Csd | Merced | 4,164 | Community | Groundwater |
| 13 | Santa Nella County Water District | Merced | 2,211 | Community | Surface water |
| 14 | Le Grand Comm Services Dist | Merced | 1,739 | Community | Groundwater |
| 15 | Castle Airport | Merced | 1,650 | Community | Groundwater |
| 16 | Hilmar Cheese Company | Merced | 1,629 | Non-transient non-community | Groundwater |
| 17 | Dole Atwater Plant | Merced | 1,500 | Non-transient non-community | Groundwater |
| 18 | Lake Yosemite County Park | Merced | 1,200 | Transient non-community | Groundwater |
| 19 | Mcswain Elementary School | Merced | 1,046 | Non-transient non-community | Groundwater |
| 20 | Liberty Packing Company LLC | Merced | 1,020 | Non-transient non-community | Groundwater |
| 21 | John Latoracca Correctional Facility | Merced | 800 | Community | Groundwater |
| 22 | San Luis Hills | Merced | 779 | Community | Surface water |
| 23 | Cdpr Four Rivers District-San Luis Creek | Merced | 653 | Transient non-community | Surface water |
| 24 | The Morning Star Packing Company | Merced | 650 | Non-transient non-community | Groundwater |
| 25 | Ingomar Packing | Merced | 600 | Non-transient non-community | Groundwater |
| 26 | Planada Elementaryschool | Merced | 567 | Non-transient non-community | Groundwater |
| 27 | Delhi Kingdom Hall | Merced | 452 | Transient non-community | Groundwater |
| 28 | Joseph Gallo Cheese Co. | Merced | 407 | Non-transient non-community | Groundwater |
| 29 | Volta Community Sd | Merced | 406 | Community | Groundwater |
| 30 | Sensient Natural Ingredients LLC | Merced | 400 | Non-transient non-community | Groundwater |
| 31 | Black Rascal Water Company | Merced | 367 | Community | Groundwater |
| 32 | Cdpr Four Rivers District-Basalt | Merced | 363 | Transient non-community | Surface water |
| 33 | Cdpr-Hatfield | Merced | 352 | Transient non-community | Groundwater |
| 34 | Turlock Golf & Country Club | Merced | 350 | Non-transient non-community | Groundwater |
| 35 | Washington School | Merced | 338 | Non-transient non-community | Groundwater |
| 36 | Charleston School | Merced | 325 | Non-transient non-community | Groundwater |
| 37 | Saputo Dairy Foods USA, LLC | Merced | 320 | Non-transient non-community | Groundwater |
| 38 | LDS Church Atwater | Merced | 300 | Transient non-community | Groundwater |
| 39 | Schelby School | Merced | 290 | Non-transient non-community | Groundwater |
| 40 | Cdpr-Mcconnell | Merced | 286 | Transient non-community | Groundwater |
| 41 | Merquin Elementary School | Merced | 284 | Non-transient non-community | Groundwater |
| 42 | Hagaman County Park | Merced | 280 | Transient non-community | Groundwater |
| 43 | LDS Church Merced | Merced | 257 | Transient non-community | Groundwater |
| 44 | Yosemite Wholesale | Merced | 250 | Non-transient non-community | Groundwater |
| 45 | Firebaugh Travel Plaza (Sw) | Merced | 250 | Transient non-community | Surface water |
| 46 | E & J Gallo Winery | Merced | 245 | Non-transient non-community | Groundwater |
| 47 | Foster Farms Delhi Feedmill Collier Road | Merced | 244 | Non-transient non-community | Groundwater |
| 48 | Ballico Csd | Merced | 238 | Community | Groundwater |
| 49 | Henderson County Park | Merced | 230 | Transient non-community | Groundwater |
| 50 | Classic Yam Water System | Merced | 224 | Non-transient non-community | Groundwater |
All other water systems in Merced County (70)
The remaining active systems filed under Merced County, largest first, with the population each reports serving.
- El Nido Elementary School220
- Merced River Resort218
- Av Thomas Produce, Inc..206
- Usfws San Luis Nwr Complex196
- Parreira Almond Processing Company, LLC174
- Cdpr-Sector Wide Potable Water Tanks172
- Turlock Auction Yard, Inc..170
- Rancho Del Rey Golf Club170
- Cressey School155
- Merced Adventist Church Water Sys.153
- Merced Golf & Country Club150
- Buhach Pentecost Hall150
- Dwr - San Luis Division O&M150
- Hughson Nut Inc.. - Livingston146
- Hilltop Ranch - Turlock Road140
- El Nido Mobile Home Park137
- Minturn Nut Co., Inc..130
- Plainsburg Elementary School122
- John B. Sanfilippo & Son, Inc..120
- Longview Mennonite School120
- Buhach Preschool (Kindercare)118
- Select Harvest USA, LLC115
- Foster Farms Chicken Livehaul (Sycamore113
- The Vista Ranch and Cellars100
- Grace Mennonite School100
- Minturn Huller95
- Livingston Properties91
- Apostolic Tabernacle75
- Snelling Merced Falls School69
- Harris Woolf Almonds-Ballico65
- Js West Milling Co Hilmar Ranch64
- Country Club County Wd64
- Merced Fruit Barn63
- Select Harvest Partners #1, Lp60
- Clausen Meat Company60
- Boland'S Market60
- Ryel Family Trust58
- Gemperle Egg Ranch55
- Yosemite Valley Beef Packing Co Inc.55
- Westside Grocery, Inc..54
- Dos Palos Y Auction Yard52
- Doreva Produce52
- Cortez Growers Asso. Water System50
- Mercey Springs Shell48
- California Sweet Potato Growers Coop48
- Garcia Farms Produce45
- Stevinson Ranch Maint. Shop/the Grove45
- Hopeton School42
- Henry Miller Reclamation District41
- Merced New Life School36
- Hilltop Ranch-Looney Road36
- Evergreen Mobile Home Park36
- Dash Dream Plant34
- Hillview Packing-Gustine33
- Stevinson Bar and Grill31
- City of Merced Wwtp30
- Pelligrini Properties (El Campo Market)30
- Snelling Chevron30
- Merced Animal Medical Center30
- San Joaquin Valley National Cemetery30
- Oxxo Mini Mart29
- Olivares Farms Water System28
- Kandola Farms Produce, Inc..27
- Cressey Store26
- Pacific Union Packing26
- Neighborhood Grocery25
- Elks Lodge Park25
- Corner Market and Deli25
- Cal Trans Chp Chowchilla River Facility25
- Foster Farms Fertilizer Plant25
Merced County water systems: frequently asked questions
How many public water systems are in Merced County, California?
EPA's SDWIS records file 120 active public water systems under Merced County, California: 22 community systems (18%), 56 non-transient non-community systems (47%) and 42 transient non-community systems (35%).
Who supplies drinking water in Merced County, CA?
The largest community water systems filed under Merced County are City of Merced (93,692 people served), City of Los Banos (47,419 people served) and City of Atwater (29,479 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.
Does Merced County's drinking water come from groundwater or surface water?
Of the 120 active public water systems in Merced County, 91% draw mainly on groundwater and 9.2% on surface water, counting purchased supplies. The largest system, City of Merced, uses groundwater.
Where can I find a water quality report for Merced County?
Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 22 community systems are filed under Merced County, so the report to look for is the one from the system that supplies your address.
How can I check violations for a water system in Merced County?
Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.
More California water systems
- All California public water systems· 7,479 active
- Santa Barbara County· 150 systems
- Mendocino County· 144 systems
- El Dorado County· 124 systems
- Santa Clara County· 121 systems
- Tuolumne County· 117 systems
- Placer County· 116 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Public water systems in Merced County, California”, https://aquacensus.com/water-systems/california/merced (data as of October 1, 2026).