PlainEnviro

EPA rankings · EPA Safe Drinking Water Information System (SDWIS) · updated August 2026

Most Public Water Systems by State

According to the U.S. Environmental Protection Agency's Safe Drinking Water Information System (most recent EPA release), all 50 states are ranked here by EPA-regulated public water systems serving their populations.

#1 · Texas
4,620
Leader
Top-12 cutoff
1,109
List threshold
State median
712
Cohort median
states ranked
51
Cohort coverage

The ranking, the verdict

Texas leads at 4,620 systems. The top-12 cutoff is 1,109 (#12), and the leader-to-tail spread is 4,527 across 51 states (median 712).

4,620
#1 Texas
1,109
top-12 list threshold
4,527
leader-to-tail spread
most recent EPA release
EPA Safe Drinking Water Information System (SDWIS) vintage

Each position reflects one reported federal count, not overall environmental quality or water safety.

Verify at EPA Envirofacts →

What This Ranking Tells Us

The number of public water systems reflects both population size and how water delivery is organized. States with many systems often have fragmented water infrastructure, numerous small community systems rather than large consolidated utilities. Texas leads the nation due to its vast geography, many small communities, and independent water districts. More systems can mean more oversight challenges, as small systems often lack the resources for advanced treatment and monitoring compared to large urban utilities.

This page ranks all 50 U.S. states and territories on a single indicator - systems - drawn directly from the EPA Safe Drinking Water Information System (SDWIS). The ranking draws on 51 state records in the current dataset, ordered descending (highest count at the top) by the underlying federal count.

A state's position depends on underlying geography, industrial history, population, and the density of reporting entities, not on a simple "cleaner" or "dirtier" label. Use the links in the table to open each state's full environmental profile and view county-level breakdowns, individual facility records, and violation history. Data source: EPA Safe Drinking Water Information System (SDWIS). All figures are as-filed and not weighted for toxicity or exposure.

Most Public Water Systems by State: top 15

Ranked by systems - full table below

  1. 1
    Texas 4,620 systems
  2. 2
    California 3,068 systems
  3. 3
    Washington 2,410 systems
  4. 4
    New York 2,242 systems
  5. 5
    North Carolina 1,958 systems
  6. 6
    Illinois 1,785 systems
  7. 7
    Pennsylvania 1,783 systems
  8. 8
    Georgia 1,722 systems
  9. 9
    Missouri 1,688 systems
  10. 10
    Florida 1,513 systems
  11. 11
    Michigan 1,434 systems
  12. 12
    Colorado 1,109 systems
  13. 13
    Ohio 1,089 systems
  14. 14
    Iowa 1,078 systems
  15. 15
    Virginia 1,050 systems

Source EPA Safe Drinking Water Information System (SDWIS) · most recent EPA release

The bar to make the top 12

1,109 systems - where #12 sits among all 51 states

1.1K lbs 22nd percentile higher than 22% of 51 states

#12 cutoff 93 lbs 4.6K lbs every state's systems, bucketed by value

Each bar is a $1M-wide band; taller bars hold more states. The dashed line and filled bar mark this facility. Hover, focus, or tap a bar for its full count, share, and position.

Source EPA Safe Drinking Water Information System (SDWIS) · most recent EPA release

1 Texas
4,620 systems
2 California
3,068 systems
3 Washington
2,410 systems
# State Systems
1 Texas TX 4,620
2 California CA 3,068
3 Washington WA 2,410
4 New York NY 2,242
5 North Carolina NC 1,958
6 Illinois IL 1,785
7 Pennsylvania PA 1,783
8 Georgia GA 1,722
9 Missouri MO 1,688
10 Florida FL 1,513
11 Michigan MI 1,434
12 Colorado CO 1,109
13 Ohio OH 1,089
14 Iowa IA 1,078
15 Virginia VA 1,050
16 Minnesota MN 998
17 Mississippi MS 989
18 Wisconsin WI 978
19 Arizona AZ 949
20 Oregon OR 943
21 Oklahoma OK 882
22 Kansas KS 855
23 Montana MT 818
24 Louisiana LA 815
25 Idaho ID 773
26 Indiana IN 712
27 New Hampshire NH 681
28 Arkansas AR 662
29 New Jersey NJ 623
30 Nebraska NE 593
31 New Mexico NM 593
32 Massachusetts MA 564
33 South Carolina SC 558
34 Utah UT 553
35 Alabama AL 546
36 South Dakota SD 513
37 Connecticut CT 505
38 Maryland MD 481
39 Tennessee TN 454
40 West Virginia WV 427
41 Alaska AK 406
42 Puerto Rico PR 402
43 Vermont VT 379
44 Kentucky KY 375
45 Maine ME 360
46 North Dakota ND 318
47 Wyoming WY 317
48 Nevada NV 230
49 Delaware DE 207
50 Hawaii HI 118
51 Rhode Island RI 93

Source: EPA Safe Drinking Water Information System (SDWIS).

Top-ranked state profiles

Explore the environmental records behind the top positions in this ranking.

#1 Texas 4,620

TRI facilities Water systems Compare

#2 California 3,068

TRI facilities Water systems Compare

#3 Washington 2,410

TRI facilities Water systems Compare

#4 New York 2,242

TRI facilities Water systems Compare

#5 North Carolina 1,958

TRI facilities Water systems Compare

#6 Illinois 1,785

TRI facilities Water systems Compare

Frequently Asked Questions

What qualifies as a public water system?

The EPA defines a public water system as one that provides water for human consumption through pipes or other infrastructure to at least 15 service connections or serves at least 25 people for at least 60 days a year. This includes community water systems (serving year-round residents), non-transient non-community systems (like schools), and transient non-community systems (like campgrounds).

Are more water systems better or worse?

Having many small systems creates oversight challenges, each system needs monitoring, treatment, and operator certification. Large consolidated systems benefit from economies of scale, professional staff, and better equipment. However, a single large system failure affects more people. The ideal is adequate-sized systems with proper resources, regardless of total count.

Explore More Rankings

Most TRI Facilities Most Toxic Releases Superfund Sites by State Water Violations by State Fewest Health-Based Records
All States
Environmental data by state
Facilities
TRI reporting facilities
Superfund Sites
EPA hazardous waste sites

What to do with this ranking

Use the leaders here as a starting point, then check your own state's full record.

  • Texas tops this list at 4,620 systems - see its full environmental profile, not just this one metric. View Texas
  • This single indicator doesn't capture the full picture. Compare against most tri facilities for a different angle. Most TRI Facilities
  • Look up any state directly to see its complete facility, water, and Superfund record in one place. Browse all states

Rankings reflect reported federal data for a single indicator; a high or low rank does not by itself measure overall environmental quality or health risk.

Read our methodology - how this data is sourced, computed, and verified.

According to the U.S. Environmental Protection Agency, this ranking is drawn from PlainEnviro's database of more than 25,000 EPA-tracked facilities and thousands of Safe Drinking Water Information System and Superfund National Priorities List records compiled since federal reporting began under the Emergency Planning and Community Right-to-Know Act in October 1986; see our methodology for the full data-source citations and refresh cadence.

Related

Browse all → | Rankings →
Data sourced from U.S. EPA environmental datasets. See our methodology for details. Retrieved and formatted by PlainEnviro

Every figure on PlainEnviro is rendered directly from EPA environmental compliance data, no number is typed in by an editor. Rankings are computed directly from EPA data. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.