Least Reliable Water Systems in Oklahoma — 2026

Out of 771 ZIP codes with data in Oklahoma, these are the lowest-ranked areas for reliability score. See also: National Least Reliable Water Systems in America | All Oklahoma Rankings

Statistic	Value
ZIP codes ranked	771
Lowest value	10/100
Median value	52/100
State	Oklahoma

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	73033	Eakly	OK	10/100	55/100
2	73053	Lookeba	OK	10/100	70/100
3	73531	Devol	OK	10/100	70/100
4	73532	Duke	OK	10/100	66/100
5	73549	Headrick	OK	10/100	68/100
6	73552	Indiahoma	OK	10/100	65/100
7	73559	Mountain Park	OK	10/100	70/100
8	73729	Cleo Springs	OK	10/100	66/100
9	73760	Meno	OK	10/100	66/100
10	74001	Avant	OK	10/100	70/100
11	74027	Delaware	OK	10/100	75/100
12	74422	Boynton	OK	10/100	55/100
13	74463	Taft	OK	10/100	55/100
14	74560	Pittsburg	OK	10/100	46/100
15	74636	Deer Creek	OK	10/100	66/100
16	74756	Sawyer	OK	10/100	66/100
17	74761	Swink	OK	10/100	66/100
18	74826	Asher	OK	10/100	70/100
19	74837	Cromwell	OK	10/100	66/100
20	74930	Bokoshe	OK	10/100	70/100
21	73014	Calumet	OK	15/100	69/100
22	73057	Maysville	OK	15/100	62/100
23	73075	Pauls Valley	OK	15/100	65/100
24	73090	Union City	OK	15/100	55/100
25	73444	Hennepin	OK	15/100	66/100
26	73446	Madill	OK	15/100	70/100
27	73527	Cache	OK	15/100	64/100
28	73529	Comanche	OK	15/100	65/100
29	73533	Duncan	OK	15/100	57/100
30	73534	Duncan	OK	15/100	63/100
31	73536	Duncan	OK	15/100	63/100
32	73542	Frederick	OK	15/100	66/100
33	73546	Grandfield	OK	15/100	55/100
34	73560	Olustee	OK	15/100	63/100
35	73565	Ryan	OK	15/100	66/100
36	73566	Snyder	OK	15/100	64/100
37	73568	Temple	OK	15/100	66/100
38	73570	Tipton	OK	15/100	70/100
39	73573	Waurika	OK	15/100	62/100
40	73641	Dill City	OK	15/100	73/100
41	73750	Kingfisher	OK	15/100	55/100
42	73762	Okarche	OK	15/100	64/100
43	74002	Barnsdall	OK	15/100	68/100
44	74003	Bartlesville	OK	15/100	60/100
45	74004	Bartlesville	OK	15/100	66/100
46	74005	Bartlesville	OK	15/100	66/100
47	74006	Bartlesville	OK	15/100	55/100
48	74020	Cleveland	OK	15/100	70/100
49	74022	Copan	OK	15/100	68/100
50	74026	Davenport	OK	15/100	67/100
51	74035	Hominy	OK	15/100	62/100
52	74047	Mounds	OK	15/100	65/100
53	74058	Pawnee	OK	15/100	70/100
54	74066	Sapulpa	OK	15/100	63/100
55	74067	Sapulpa	OK	15/100	78/100
56	74369	Welch	OK	15/100	70/100
57	74401	Muskogee	OK	15/100	69/100
58	74402	Muskogee	OK	15/100	65/100
59	74403	Muskogee	OK	15/100	59/100
60	74421	Beggs	OK	15/100	70/100
61	74426	Checotah	OK	15/100	70/100
62	74432	Eufaula	OK	15/100	70/100
63	74435	Gore	OK	15/100	58/100
64	74436	Haskell	OK	15/100	70/100
65	74446	Okay	OK	15/100	70/100
66	74447	Okmulgee	OK	15/100	65/100
67	74450	Oktaha	OK	15/100	55/100
68	74460	Schulter	OK	15/100	55/100
69	74462	Stigler	OK	15/100	75/100
70	74467	Wagoner	OK	15/100	65/100
71	74468	Wainwright	OK	15/100	62/100
72	74477	Wagoner	OK	15/100	66/100
73	74501	Mcalester	OK	15/100	65/100
74	74502	Mcalester	OK	15/100	66/100
75	74521	Albion	OK	15/100	66/100
76	74523	Antlers	OK	15/100	70/100
77	74525	Atoka	OK	15/100	70/100
78	74536	Clayton	OK	15/100	37/100
79	74542	Atoka	OK	15/100	66/100
80	74547	Hartshorne	OK	15/100	61/100
81	74553	Kiowa	OK	15/100	70/100
82	74554	Krebs	OK	15/100	70/100
83	74558	Nashoba	OK	15/100	66/100
84	74561	Quinton	OK	15/100	62/100
85	74565	Savanna	OK	15/100	82/100
86	74569	Stringtown	OK	15/100	70/100
87	74571	Talihina	OK	15/100	70/100
88	74577	Whitesboro	OK	15/100	55/100
89	74578	Wilburton	OK	15/100	62/100
90	74637	Fairfax	OK	15/100	70/100
91	74727	Boswell	OK	15/100	66/100
92	74735	Fort Towson	OK	15/100	70/100
93	74738	Grant	OK	15/100	78/100
94	74743	Hugo	OK	15/100	70/100
95	74745	Idabel	OK	15/100	65/100
96	74801	Shawnee	OK	15/100	60/100
97	74802	Shawnee	OK	15/100	70/100
98	74804	Shawnee	OK	15/100	60/100
99	74848	Holdenville	OK	15/100	70/100
100	74873	Tecumseh	OK	15/100	40/100

Methodology

Water system reliability scores (0-100) combine violation frequency, violation recency, resolution rate, and system size. Systems with repeated health-based violations and unresolved issues score lowest. The reliability score focuses specifically on the water utility performance, distinct from the broader Home Safety Score.

Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-04-13.

Frequently Asked Questions

What does a low water reliability score mean?

A low reliability score (below 50) indicates a water system with frequent violations, poor resolution rates, or recurring compliance issues. These systems may have aging infrastructure, inadequate treatment, or management challenges.

How is reliability different from safety score?

The reliability score focuses specifically on the water utility performance (violations, resolution, compliance). The Home Safety Score is broader, also including lead risk, radon, and flood data. A ZIP code can have a reliable water system but still have high radon or flood risk.