Clean Water Act Violations by State: 804,549 Permitted Facilities in EPA Enforcement Data

What this page is. Clean Water Act compliance and enforcement data for every US state and the District of Columbia, retrieved directly from EPA’s Enforcement and Compliance History Online system. It covers 804,549 permitted discharge facilities, 15,968 serious violators, 77,498 violations in the most recent three-year window and 10,942 formal enforcement actions. This is the wastewater side of the water system, the pipes and treatment works that receive what buildings discharge.

The caveat that has to lead. Serious violator rates in this data range from 13.20 percent in Washington to 0.02 percent in Hawaii, a spread of roughly 600 times. No plausible difference in actual wastewater compliance is that large. The variation is driven substantially by how each state implements and reports under a delegated permitting programme. This is an enforcement-practice map before it is a pollution map.

What the table shows

• EPA holds Clean Water Act records for 804,549 permitted facilities across the 50 states and the District of Columbia.
• 15,968 are flagged as serious violators, a national rate of 1.98 percent.
• That rate is about 2.6 times the equivalent Safe Drinking Water Act rate of 0.77 percent.
• 77,498 violations were recorded in the most recent three-year window and 42,323 remain open.
• Formal enforcement actions totalled 10,942, or 13.6 per 1,000 facilities, roughly half the rate seen under the drinking water programme.
• Washington reports the highest serious violator rate at 13.20 percent, from 2,579 designations across 19,538 facilities.
• California, with 51,491 facilities, reports 57 serious violators, a rate of 0.11 percent.
• Louisiana and Pennsylvania each hold more than 38,000 permitted facilities, among the largest regulated populations in the country.

Every state and DC

Ranked by serious violator rate. Read alongside the limitations section below.

Rank	State	Permitted facilities	Serious violators	Rate	Violations (3 yr)	Formal actions
1	Washington	19,538	2,579	13.20%	7,292	332
2	Ohio	4,741	369	7.78%	2,705	149
3	Iowa	2,219	127	5.72%	1,119	81
4	Oregon	9,086	468	5.15%	706	258
5	Maryland	9,560	488	5.10%	1,643	156
6	West Virginia	29,280	1,375	4.70%	3,445	380
7	Louisiana	39,251	1,838	4.68%	6,704	1,341
8	New York	20,859	844	4.05%	4,023	973
9	Pennsylvania	38,564	1,488	3.86%	6,992	786
10	Michigan	7,210	265	3.68%	2,658	126
11	Arkansas	11,899	374	3.14%	1,266	352
12	Illinois	22,011	660	3.00%	2,468	563
13	Connecticut	4,567	128	2.80%	576	40
14	Mississippi	9,313	260	2.79%	1,129	143
15	Oklahoma	2,260	58	2.57%	466	380
16	Nebraska	1,951	49	2.51%	400	22
17	Vermont	1,994	47	2.36%	237	6
18	Tennessee	29,440	577	1.96%	1,334	180
19	Minnesota	3,198	58	1.81%	700	279
20	Massachusetts	13,911	237	1.70%	818	222
21	Kentucky	31,063	483	1.55%	2,413	537
22	Virginia	18,573	274	1.48%	1,895	341
23	Missouri	39,552	580	1.47%	3,965	264
24	Nevada	5,958	86	1.44%	94	4
25	New Mexico	15,197	202	1.33%	465	212
26	New Hampshire	4,943	65	1.31%	256	66
27	North Dakota	9,341	107	1.15%	624	12
28	Wyoming	6,485	72	1.11%	711	15
29	Wisconsin	9,055	91	1.00%	962	15
30	New Jersey	20,776	185	0.89%	3,183	267
31	Alaska	11,974	105	0.88%	1,302	67
32	Colorado	43,877	373	0.85%	2,694	214
33	Idaho	10,639	87	0.82%	726	171
34	Rhode Island	1,617	13	0.80%	180	35
35	Alabama	48,485	358	0.74%	1,607	174
36	South Dakota	4,326	26	0.60%	217	17
37	Maine	2,745	15	0.55%	244	14
38	District of Columbia	938	5	0.53%	40	9
39	Montana	14,160	74	0.52%	800	32
40	Indiana	33,395	166	0.50%	1,362	103
41	Delaware	288	1	0.35%	40	11
42	South Carolina	22,965	68	0.30%	808	148
43	Kansas	24,581	57	0.23%	514	87
44	North Carolina	26,179	59	0.23%	1,446	417
45	Arizona	15,235	30	0.20%	329	25
46	California	51,491	57	0.11%	3,305	571
47	Utah	41,058	38	0.09%	460	145
48	Hawaii	8,801	2	0.02%	175	200
49	Florida	0	0	0.00%	0	0
50	Georgia	0	0	0.00%	0	0
51	Texas	0	0	0.00%	0	0

Source: US EPA Enforcement and Compliance History Online, Clean Water Act services, retrieved 25 September 2026. Rates calculated by The Plumbing Brief.

Sourced figures

1. Permitted facilities: 804,549. Source: US EPA ECHO, CWA services, 25 September 2026.
2. Serious violators: 15,968, a national rate of 1.98 percent. Source: US EPA ECHO.
3. Violations in the three-year window: 77,498. Source: US EPA ECHO.
4. Currently open violations: 42,323. Source: US EPA ECHO.
5. Formal enforcement actions: 10,942, or 13.6 per 1,000 facilities. Source: US EPA ECHO.
6. Informal enforcement actions: 37,088. Source: US EPA ECHO.
7. Highest serious violator rate: Washington, 13.20 percent (2,579 of 19,538). Source: US EPA ECHO.
8. Next highest: Ohio 7.78 percent, Iowa 5.72 percent, Oregon 5.15 percent, Maryland 5.10 percent. Source: US EPA ECHO.
9. Lowest among large states: California 0.11 percent (57 of 51,491) and Utah 0.09 percent (38 of 41,058). Source: US EPA ECHO.
10. Largest regulated populations: California 51,491, Utah 41,058, Louisiana 39,251, Pennsylvania 38,564. Source: US EPA ECHO.
11. Equivalent Safe Drinking Water Act serious violator rate: 0.77 percent across 431,258 systems. Source: US EPA ECHO, SDWA services.
12. National wastewater infrastructure need is assessed separately through EPA’s Clean Watersheds Needs Survey. Source: US EPA.

What we calculated

Derived finding 1: the wastewater violation rate runs 2.6 times the drinking water rate

Formula. Clean Water Act serious violator rate divided by Safe Drinking Water Act serious violator rate, both from ECHO on the same retrieval date.

Calculation. 1.98 percent divided by 0.77 percent equals approximately 2.6.

Finding. Facilities regulated under the Clean Water Act are flagged as serious violators at roughly 2.6 times the rate of systems regulated under the Safe Drinking Water Act. Both programmes were queried on the same day through the same system.

Inputs. US EPA ECHO, CWA and SDWA services, 25 September 2026.

Limitations. The two programmes regulate different things with different definitions of a serious violator and different regulated populations. This ratio compares two enforcement programmes, not two levels of environmental harm.

Derived finding 2: a 600-fold spread between states

Formula. Highest state serious violator rate divided by lowest, restricted to states with more than 50 facilities.

Calculation. 13.20 percent in Washington divided by 0.02 percent in Hawaii equals approximately 600.

Finding. Reported serious violator rates vary roughly 600-fold between states. California holds 2.6 times as many permitted facilities as Washington and reports 2 percent as many serious violators. That gap cannot be explained by compliance behaviour alone.

Inputs. US EPA ECHO CWA services.

Limitations. This finding demonstrates that the data is not comparable across states at face value. It is not a claim that any state is failing to enforce, and it should never be cited as a ranking of water pollution.

Derived finding 3: formal enforcement is rarer on the wastewater side

Formula. Formal enforcement actions per 1,000 regulated entities, compared between the two programmes.

Calculation. 13.6 per 1,000 under the Clean Water Act against 24.0 per 1,000 under the Safe Drinking Water Act.

Finding. Formal enforcement actions occur at roughly half the per-entity rate under the Clean Water Act compared with the drinking water programme, despite the higher serious violator rate.

Inputs. US EPA ECHO, both services.

Limitations. The regulated populations differ in size and character, and formal action is not the only enforcement tool. This is a comparison of recorded formal actions per entity, not of enforcement effectiveness.

How this report was built

Methodology

Source. Every figure was retrieved from EPA ECHO Clean Water Act REST services, one query per state, on 25 September 2026. The drinking water comparison figures were retrieved from the SDWA services on the same day so the two are contemporaneous.

Calculated columns. Serious violator rate, the cross-programme ratio, the state spread and formal actions per 1,000 are calculated here, with formulas stated.

Why the caveat leads. A table of state violation rates invites a pollution ranking. This data does not support one, and saying so after the table would be too late.

Last updated. 25 September 2026. ECHO is a live system and later retrievals will differ.

Data limitations

• State rates are not comparable at face value. A 600-fold spread reflects delegated programme implementation and reporting, not a 600-fold difference in compliance.
• The permitted facility count includes stormwater and general permit holders as well as wastewater treatment works, so it is not a count of sewage plants.
• Most Clean Water Act programmes are administered by authorised states rather than EPA directly, and data submission practice varies.
• A violation is a recorded compliance event, which includes reporting failures as well as discharge exceedances. This page does not separate them.
• ECHO is updated continuously and late reporting is common, so a figure retrieved on a different date will differ.
• Nothing here describes water quality in any specific waterway, nor the performance of any named facility.
• This page names no individual facility or operator. It reports state aggregates only.

Source quality ranking

Tier 1. US EPA Enforcement and Compliance History Online, Clean Water Act and Safe Drinking Water Act REST services.

Tier 2. None used.

Tier 3. None used.

Excluded. Any state pollution ranking built on this data without the comparability caveat, and any facility-level characterisation.

If you quote one number

• EPA holds Clean Water Act records for 804,549 permitted facilities, nearly twice the number of public water systems.
• Serious violator rates vary roughly 600-fold between states, which tells you more about enforcement than about pollution.
• California has 2.6 times as many permitted facilities as Washington and reports 2 percent as many serious violators.
• Wastewater facilities are flagged as serious violators at 2.6 times the rate of drinking water systems.
• 42,323 Clean Water Act violations are currently open.

Summary for reporters

EPA holds Clean Water Act compliance records for 804,549 permitted discharge facilities across the 50 states and the District of Columbia, of which 15,968 are flagged as serious violators, a national rate of 1.98 percent, according to data retrieved from the agency’s Enforcement and Compliance History Online system on 25 September 2026. The records show 77,498 violations in the most recent three-year window with 42,323 still open, and 10,942 formal enforcement actions. The wastewater serious violator rate runs about 2.6 times the equivalent Safe Drinking Water Act rate of 0.77 percent, queried the same day. State rates range from 13.20 percent in Washington to 0.02 percent in Hawaii, a roughly 600-fold spread that reflects how states implement and report under a delegated permitting programme rather than a comparable difference in compliance. California holds 2.6 times as many permitted facilities as Washington and reports 2 percent as many serious violators.

Angles this supports

1. Clean Water Act violation rates vary 600-fold between states
2. California has more permitted dischargers than any state and almost no serious violators on paper
3. Wastewater facilities are flagged at 2.6 times the rate of drinking water systems
4. 42,323 Clean Water Act violations are still open
5. What EPA’s enforcement map actually measures

Download the data

Every figure in the table above is published as a CSV under a Creative Commons Attribution 4.0 licence. Attribution: The Plumbing Brief.

All 51 jurisdictions with facilities, violations and enforcement (CSV)

Questions this answers

How many facilities are regulated under the Clean Water Act? 804,549 permitted facilities across the 50 states and DC, per EPA ECHO on 25 September 2026. That includes stormwater and general permit holders, not only treatment plants.

How many Clean Water Act violations are there? 77,498 in the most recent three-year window, of which 42,323 remain open.

Which state has the worst Clean Water Act record? Washington has the highest reported serious violator rate at 13.20 percent, but that reflects how the state designates and reports rather than a measure of pollution. This data does not support a state pollution ranking.

Why does California report so few serious violators? California holds 51,491 permitted facilities and reports 57 serious violators, 0.11 percent. The most likely explanation is a difference in designation and reporting practice under its delegated programme, not near-perfect compliance.

Is wastewater compliance worse than drinking water compliance? The Clean Water Act serious violator rate is 1.98 percent against 0.77 percent for drinking water, about 2.6 times. The two programmes use different definitions and regulate different populations, so this compares enforcement programmes rather than environmental harm.

How much enforcement happens? 10,942 formal actions and 37,088 informal ones, about 13.6 formal actions per 1,000 facilities, roughly half the per-entity rate under the drinking water programme.

Does a violation mean sewage was released? Not necessarily. Recorded violations include reporting and monitoring failures alongside discharge exceedances, and this page does not separate them.

Who enforces the Clean Water Act? Most programmes are administered by authorised states rather than EPA directly, which is why implementation and reporting vary so widely.

Where does this data come from? EPA’s Enforcement and Compliance History Online system, queried state by state through its Clean Water Act REST services.

Can I look up a specific facility? Yes, through EPA’s ECHO search tool. This page reports state aggregates only and names no individual facility.

Last reviewed: 2026-09-25.

How to cite this report

The Plumbing Brief, “Clean Water Act Violations by State: 804,549 Permitted Facilities in EPA Enforcement Data”, https://theplumbingbrief.com/clean-water-act-violations-by-state/, accessed [date].