Water Systems by State
Public water system data broken down by U.S. state, from 433,698 water systems serving 333,711,118 people.
The number of public water systems in a state reflects both its population size and the structure of its water utility landscape. Some states rely primarily on large centralized utilities serving millions of customers, while others have thousands of small community water systems serving rural towns and subdivisions. States with extensive rural populations, such as Texas, Pennsylvania, and Ohio, tend to have the most water systems because small, independent utilities are more common outside metropolitan areas.
Public Water Systems by State
All U.S. states with public water systems in the EPA Safe Drinking Water database, sorted by system count.
| # | State | Water Systems | Browse |
|---|---|---|---|
| 1 | Michigan (MI) | 26,702 | Browse |
| 2 | Illinois (IL) | 25,921 | Browse |
| 3 | New York (NY) | 24,700 | Browse |
| 4 | Wisconsin (WI) | 23,977 | Browse |
| 5 | North Carolina (NC) | 23,899 | Browse |
| 6 | Pennsylvania (PA) | 22,508 | Browse |
| 7 | Minnesota (MN) | 21,722 | Browse |
| 8 | California (CA) | 20,012 | Browse |
| 9 | Florida (FL) | 19,286 | Browse |
| 10 | Ohio (OH) | 16,272 | Browse |
| 11 | Texas (TX) | 16,217 | Browse |
| 12 | New Jersey (NJ) | 14,893 | Browse |
| 13 | Connecticut (CT) | 10,866 | Browse |
| 14 | Washington (WA) | 10,042 | Browse |
| 15 | Indiana (IN) | 9,888 | Browse |
| 16 | Virginia (VA) | 8,965 | Browse |
| 17 | Maryland (MD) | 7,874 | Browse |
| 18 | Tennessee (TN) | 6,173 | Browse |
| 19 | Missouri (MO) | 6,155 | Browse |
| 20 | Oregon (OR) | 6,033 | Browse |
| 21 | Maine (ME) | 5,888 | Browse |
| 22 | Iowa (IA) | 5,291 | Browse |
| 23 | Georgia (GA) | 5,256 | Browse |
| 24 | Oklahoma (OK) | 5,034 | Browse |
| 25 | Louisiana (LA) | 5,013 | Browse |
| 26 | Colorado (CO) | 4,987 | Browse |
| 27 | Montana (MT) | 4,730 | Browse |
| 28 | South Carolina (SC) | 4,556 | Browse |
| 29 | Idaho (ID) | 4,378 | Browse |
| 30 | Arizona (AZ) | 4,340 | Browse |
| 31 | West Virginia (WV) | 4,250 | Browse |
| 32 | Vermont (VT) | 4,137 | Browse |
| 33 | Arkansas (AR) | 3,969 | Browse |
| 34 | New Hampshire (NH) | 3,958 | Browse |
| 35 | Massachusetts (MA) | 3,786 | Browse |
| 36 | Alaska (AK) | 3,554 | Browse |
| 37 | Mississippi (MS) | 3,209 | Browse |
| 38 | Nebraska (NE) | 2,756 | Browse |
| 39 | New Mexico (NM) | 2,740 | Browse |
| 40 | Utah (UT) | 2,324 | Browse |
| 41 | Kentucky (KY) | 2,214 | Browse |
| 42 | Alabama (AL) | 1,867 | Browse |
| 43 | Wyoming (WY) | 1,851 | Browse |
| 44 | Kansas (KS) | 1,809 | Browse |
| 45 | South Dakota (SD) | 1,693 | Browse |
| 46 | North Dakota (ND) | 1,605 | Browse |
| 47 | Nevada (NV) | 1,529 | Browse |
| 48 | Delaware (DE) | 1,344 | Browse |
| 49 | Rhode Island (RI) | 1,141 | Browse |
| 50 | Puerto Rico (PR) | 991 | Browse |
| 51 | Virgin Islands (VI) | 829 | Browse |
| 52 | American Samoa (AS) | 285 | Browse |
| 53 | Northern Mariana Islands (MP) | 200 | Browse |
| 54 | Hawaii (HI) | 153 | Browse |
| 55 | District of Columbia (DC) | 48 | Browse |
| 56 | Guam (GU) | 19 | Browse |
System count includes all active and inactive public water systems in the EPA Safe Drinking Water Information System (SDWIS).
Understanding State Water System Counts
Community vs. Non-Community Systems
Public water systems include more than just the utilities that deliver drinking water to homes. The EPA's Safe Drinking Water Information System also tracks non-transient non-community systems (schools, offices, factories with their own wells) and transient non-community systems (campgrounds, gas stations, rest areas). States with significant rural populations and industry may have large numbers of these smaller, non-residential water systems that inflate the total count relative to the residential population served.
Violations and Safe Water
Having more water systems does not mean a state has more contamination, it often simply reflects the fragmented nature of rural water infrastructure. Small water systems typically have fewer resources for treatment and compliance than large utilities, and they represent a disproportionate share of health-based violations nationally. When evaluating water safety by state, the violation rate (violations per system) provides more insight than raw system counts alone. Browse individual systems to see their specific violation history.
Explore Water Safety Data
Browse water systems, search by contaminant, or view full statistics.