State Water Quality Rankings

Rankings based on EPA Lead and Copper Rule monitoring data. Lower violation rates and lead levels indicate better water quality compliance.

Most Lead Violations

States with the highest number of water systems exceeding the EPA's 15 ppb lead action level

Rank	State	Lead Violations	Total Systems	Avg Lead Level	Population	Risk
1	Pennsylvania	1206	22,622	11.43 ppb	12.6M	Elevated
2	North Carolina	494	23,923	5.58 ppb	9.9M	Elevated
3	New Hampshire	482	4,131	27.64 ppb	1.2M	High
4	New Jersey	249	14,932	5.31 ppb	9.5M	Elevated
5	Ohio	223	16,365	3.86 ppb	11.1M	Moderate
6	Michigan	161	27,019	3.65 ppb	9.1M	Moderate
7	New York	153	26,516	3.97 ppb	19.3M	Moderate
8	California	142	20,579	2.31 ppb	42.7M	Moderate
9	Indiana	119	9,915	3.97 ppb	5.7M	Moderate
10	Minnesota	109	21,775	3.17 ppb	5.3M	Moderate
11	Virginia	109	9,028	3.73 ppb	7.9M	Moderate
12	Florida	105	19,917	2.92 ppb	22.3M	Moderate
13	Illinois	91	26,675	2.66 ppb	12.6M	Moderate
14	Connecticut	74	11,255	3.46 ppb	3.0M	Moderate
15	South Carolina	65	5,512	4.13 ppb	4.7M	Moderate
16	Washington	61	10,086	2.67 ppb	9.9M	Moderate
17	Wisconsin	59	24,118	2.81 ppb	5.1M	Moderate
18	Maryland	56	7,992	2.89 ppb	6.0M	Moderate
19	Texas	52	16,249	1.48 ppb	33.1M	Moderate
20	Arkansas	51	3,972	4.54 ppb	3.0M	Moderate
21	Oregon	51	6,071	2.92 ppb	4.0M	Moderate
22	Georgia	50	5,716	2.25 ppb	10.7M	Moderate
23	Puerto Rico	50	1,000	7.76 ppb	3.3M	Elevated
24	U.S. Virgin Islands	49	1,077	15.95 ppb	123K	High
25	Alaska	47	3,661	3.94 ppb	855K	Moderate
26	Massachusetts	46	3,929	3.45 ppb	10.4M	Moderate
27	Vermont	43	4,304	3.87 ppb	635K	Moderate
28	West Virginia	42	4,357	3.62 ppb	1.6M	Moderate
29	Louisiana	40	5,089	2.33 ppb	5.3M	Moderate
30	Delaware	32	1,387	4.24 ppb	1.1M	Moderate
31	Maine	32	6,141	2.99 ppb	922K	Moderate
32	Arizona	31	4,383	2.31 ppb	7.7M	Moderate
33	Missouri	31	6,167	2.40 ppb	6.0M	Moderate
34	Rhode Island	30	1,147	6.02 ppb	1.1M	Elevated
35	Oklahoma	29	5,688	1.87 ppb	3.7M	Moderate
36	Montana	28	4,736	2.74 ppb	1.1M	Moderate
37	Kansas	23	1,814	2.50 ppb	2.9M	Moderate
38	New Mexico	22	2,786	2.92 ppb	2.1M	Moderate
39	Idaho	21	4,387	2.44 ppb	1.8M	Moderate
40	Iowa	18	5,369	2.66 ppb	3.1M	Moderate
41	Mississippi	18	3,209	2.12 ppb	3.3M	Moderate
42	Colorado	17	5,105	2.33 ppb	7.5M	Moderate
43	Utah	15	2,385	3.00 ppb	3.9M	Moderate
44	Tennessee	12	6,170	2.89 ppb	8.1M	Moderate
45	Nevada	10	1,566	2.07 ppb	3.5M	Moderate
46	Alabama	7	1,873	2.23 ppb	6.2M	Moderate
47	Northern Mariana Islands	7	223	4.16 ppb	70K	Moderate
48	Nebraska	7	2,779	2.28 ppb	1.8M	Moderate
49	Hawaii	6	237	1.21 ppb	1.5M	Moderate
50	Wyoming	6	1,877	2.34 ppb	638K	Moderate
51	North Dakota	5	1,606	1.95 ppb	751K	Moderate
52	South Dakota	4	1,715	2.43 ppb	968K	Moderate
53	District of Columbia	2	48	4.75 ppb	701K	Moderate
54	Kentucky	1	2,232	1.68 ppb	4.6M	Moderate
55	Navajo Nation	1	72	4.34 ppb	0	Moderate

Highest Violation Rate

States with the most violations per water system (accounts for state size)

#1High

New Hampshire

11.7%

violation rate

Lead: 482Copper: 0Total: 4131

#2Elevated

Pennsylvania

5.3%

violation rate

Lead: 1206Copper: 0Total: 22622

#3Elevated

Puerto Rico

5.0%

violation rate

Lead: 50Copper: 0Total: 1000

#4High

U.S. Virgin Islands

4.5%

violation rate

Lead: 49Copper: 0Total: 1077

#5Moderate

District of Columbia

4.2%

violation rate

Lead: 2Copper: 0Total: 48

#6Moderate

Northern Mariana Islands

3.1%

violation rate

Lead: 7Copper: 0Total: 223

#7Elevated

Rhode Island

2.6%

violation rate

Lead: 30Copper: 0Total: 1147

#8Moderate

Hawaii

2.5%

violation rate

Lead: 6Copper: 0Total: 237

#9Moderate

Delaware

2.3%

violation rate

Lead: 32Copper: 0Total: 1387

#10Elevated

North Carolina

2.1%

violation rate

Lead: 494Copper: 0Total: 23923

#11Elevated

New Jersey

1.7%

violation rate

Lead: 249Copper: 0Total: 14932

#12Moderate

Navajo Nation

1.4%

violation rate

Lead: 1Copper: 0Total: 72

Highest Average Lead Levels

Average lead concentration across all tested systems. Even below 15 ppb, lead exposure is a concern. The health goal is zero.

Rank	State	Avg Lead (ppb)	vs. Action Level	Systems Tested
1	New Hampshire	27.64	100%	554
2	U.S. Virgin Islands	15.95	100%	130
3	Pennsylvania	11.43	76%	4,037
4	Puerto Rico	7.76	52%	386
5	Rhode Island	6.02	40%	232
6	North Carolina	5.58	37%	3,090
7	New Jersey	5.31	35%	2,599
8	Region 08	5.00	33%	1
9	Region 09	5.00	33%	6
10	District of Columbia	4.75	32%	25
11	Arkansas	4.54	30%	852
12	Navajo Nation	4.34	29%	29
13	Delaware	4.24	28%	489
14	Northern Mariana Islands	4.16	28%	70
15	South Carolina	4.13	28%	1,291
16	Indiana	3.97	26%	2,243
17	New York	3.97	26%	4,659
18	Alaska	3.94	26%	1,025
19	Vermont	3.87	26%	799
20	Ohio	3.86	26%	2,974

Cleanest States

States with zero violations and the lowest average lead levels

Zero violations

Region 01

0.00 ppb avg

1 systems

Zero violations

Region 02

0.00 ppb avg

2 systems

Zero violations

Region 05

0.00 ppb avg

2 systems

Zero violations

Region 07

0.00 ppb avg

2 systems

Zero violations

Region 10

0.00 ppb avg

9 systems

Zero violations

0.00 ppb avg

2 systems

Zero violations

0.00 ppb avg

3 systems

Zero violations

0.00 ppb avg

3 systems

Zero violations

0.00 ppb avg

1 systems

Zero violations

0.44 ppb avg

1 systems

Methodology:Rankings are based on EPA SDWIS Lead and Copper Rule (LCR) monitoring data. “Lead violations” means the system's 90th percentile lead level exceeded the EPA action level of 15 ppb (0.015 mg/L). “Violation rate” is calculated as (lead violations + copper violations) / total systems. Average lead level is the arithmetic mean of most recent reported 90th percentile values across all systems with available data.Full methodology →