California Water Systems Serving the Most Disadvantaged Populations — 2026
California community water utilities serving populations with the highest combined percent of non-white residents and households below 200% of the Federal Poverty Level (Census ACS 2019-2023, aggregated via EPA CWS Service Area Boundaries v3).
ranked
with demographic data
vintage
boundaries (March 2026)
These 50 California water utilities serve populations with the highest combined percent of non-white residents and households below 200% of the Federal Poverty Level. Within-size-class percentile rankings neutralize the confound of system size; no geographic cap is applied at the state level because all utilities are within a single state.
| Rank | Water System | State | Pop served | Equity score | % PoC served | % Below 200% FPL | Unresolved violations |
|---|---|---|---|---|---|---|---|
| 1 | City of Mendota | California | 8,464 | 99.8 | 97% | 71% | — |
| 2 | Arvin Community Services District | California | 9,637 | 99.4 | 96% | 64% | 1 |
| 3 | Lamont Public Utility District | California | 10,080 | 99.4 | 95% | 71% | — |
| 4 | Orosi Public Utility District | California | 7,316 | 99.4 | 96% | 71% | — |
| 5 | Earlimart PUD | California | 7,202 | 99.4 | 98% | 58% | 1 |
| 6 | Firebaugh City | California | 7,542 | 99.2 | 95% | 63% | — |
| 7 | City of Parlier | California | 12,388 | 99.1 | 97% | 58% | 1 |
| 8 | Gswc - Bell, Bell Gardens | California | 47,440 | 98.9 | 97% | 56% | — |
| 9 | City of Orange Cove | California | 7,563 | 98.8 | 95% | 58% | 1 |
| 10 | City of Bell Gardens | California | 6,207 | 98.8 | 97% | 55% | — |
| 11 | Gswc - Florence/Graham | California | 53,692 | 98.7 | 99% | 52% | — |
| 12 | City of Avenal | California | 4,483 | 98.4 | 92% | 58% | 6 |
| 13 | Greenfield County Water District | California | 11,406 | 98.3 | 90% | 61% | — |
| 14 | City of Wasco | California | 25,485 | 97.8 | 92% | 53% | — |
| 15 | Wasco St. Prison Reception Ctr | California | 4,303 | 97.8 | 92% | 53% | — |
| 16 | Maywood Mutual Water Co. #2 | California | 25,908 | 97.6 | 99% | 48% | — |
| 17 | Maywood Mutual Water Company #3 | California | 25,908 | 97.6 | 99% | 48% | — |
| 18 | City of Calexico | California | 36,151 | 97.5 | 98% | 49% | 1 |
| 19 | City of Corcoran | California | 12,383 | 97.5 | 88% | 54% | — |
| 20 | City of Farmersville | California | 7,495 | 97.2 | 84% | 57% | 1 |
| 21 | Huntington Park-City, Water Department | California | 38,154 | 97.1 | 99% | 48% | — |
| 22 | Maywood Mutual Water Company #1 | California | 6,711 | 97.1 | 99% | 47% | — |
| 23 | Walnut Park Mutual Water Company | California | 16,644 | 96.9 | 99% | 47% | — |
| 24 | City of Dinuba | California | 22,497 | 96.8 | 89% | 51% | 1 |
| 25 | Lynwood-City, Water Department | California | 50,520 | 96.7 | 98% | 47% | — |
| 26 | City of Lindsay | California | 10,929 | 96.6 | 86% | 51% | 32 |
| 27 | City of Woodlake | California | 6,292 | 96.6 | 82% | 53% | — |
| 28 | California Water Service Company - Ela | California | 98,977 | 96.4 | 98% | 46% | — |
| 29 | Castroville Community Services District | California | 3,625 | 96.4 | 93% | 48% | — |
| 30 | City of Dos Palos | California | 7,477 | 96.2 | 82% | 52% | 14 |
| 31 | City of Madera | California | 58,107 | 96.1 | 86% | 49% | — |
| 32 | City of Delano | California | 38,961 | 96 | 95% | 47% | — |
| 33 | Liberty Utilities - Lynwood | California | 18,244 | 96 | 99% | 45% | — |
| 34 | San Bernardino City | California | 175,812 | 96 | 88% | 44% | — |
| 35 | City of Greenfield | California | 15,367 | 95.8 | 97% | 45% | — |
| 36 | Guadalupe Water Department | California | 5,974 | 95.8 | 92% | 47% | — |
| 37 | City of Adelanto | California | 7,163 | 95.7 | 90% | 47% | — |
| 38 | El Monte-City, Water Department | California | 15,771 | 95.6 | 96% | 45% | — |
| 39 | Cws - Bakersfield | California | 249,635 | 95.4 | 81% | 51% | — |
| 40 | Alco Water Service | California | 50,911 | 95.4 | 96% | 45% | — |
| 41 | Ivanhoe Public Utility District | California | 4,086 | 95.4 | 88% | 47% | 1 |
| 42 | City of El Centro | California | 38,313 | 95 | 91% | 46% | — |
| 43 | City of Porterville | California | 48,713 | 95 | 79% | 49% | 1 |
| 44 | City of Brawley | California | 25,171 | 94.3 | 87% | 45% | — |
| 45 | Palmdale Water Dist. | California | 122,149 | 94.2 | 88% | 42% | — |
| 46 | City of Shafter | California | 16,831 | 94.1 | 83% | 46% | — |
| 47 | City of Blythe - | California | 9,694 | 94 | 74% | 49% | — |
| 48 | Chuckawalla Valley State Prison | California | 5,961 | 94 | 74% | 49% | — |
| 49 | Liberty Utilities - Compton | California | 11,987 | 93.8 | 98% | 42% | — |
| 50 | Mission Springs Water District | California | 42,266 | 93.8 | 75% | 48% | — |
How to read this ranking
Each row links to a full utility profile with violation history, lead testing results, and service-area ZIPs. The demographic context columns are from independent data sources (ACS, not EJScreen) and are provided for readers who want to examine equity patterns alongside the operational data.
See the full methodology for calculation details, data vintages, and known limitations.
Frequently asked questions
What does the "equity score" mean?
A 0-100 composite that combines two within-size-class percentile ranks: (1) percent of population served that is non-white (Census ACS B03002), and (2) percent below 200 percent of the Federal Poverty Level (Census ACS C17002). Within-size-class comparison (small, medium, large) is used because small rural systems and large urban systems have structurally different demographic profiles; mixing them in a single ranking produces a methodologically weak list dominated by size rather than disparity.
Why is the list capped at 5 systems per state?
Without a cap, the list concentrates in states with large numbers of historically disadvantaged small-to-medium systems (Texas, California). A geographic diversity cap produces a more nationally-representative snapshot. Per-state rankings, if available, show the full within-state comparison without a cap.
Does this claim discrimination?
No. It reports a demographic fact: these water utilities serve populations that are more non-white and lower-income than the national median, after controlling for system size. Causation — why that pattern exists — is a separate research question requiring different data and methods.
ZipCheckup is an independent public-data tool. We are a referral service and do not provide water testing, remediation, or utility services. Rankings reflect publicly-available federal data and are provided for informational purposes. For issues with your specific water system, contact your local water utility or state drinking water program.