Least Reliable Water Systems in Missouri — 2026

Out of 1,194 ZIP codes with data in Missouri, these are the lowest-ranked areas for reliability score. See also: National Least Reliable Water Systems in America | All Missouri Rankings

Statistic	Value
ZIP codes ranked	1,194
Lowest value	15/100
Median value	75/100
State	Missouri

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	63653	Leadwood	MO	15/100	58/100
2	63824	Blodgett	MO	20/100	86/100
3	63353	Louisiana	MO	25/100	56/100
4	63377	Silex	MO	25/100	48/100
5	63650	Ironton	MO	25/100	48/100
6	63654	Lesterville	MO	25/100	64/100
7	65712	Mount Vernon	MO	25/100	78/100
8	63740	Chaffee	MO	27/100	74/100
9	64725	Archie	MO	28/100	61/100
10	63640	Farmington	MO	30/100	68/100
11	64073	Mosby	MO	30/100	45/100
12	64469	Maysville	MO	30/100	72/100
13	63870	Parma	MO	31/100	92/100
14	63820	Anniston	MO	34/100	88/100
15	65320	Arrow Rock	MO	34/100	77/100
16	63456	Monroe City	MO	35/100	58/100
17	63555	Memphis	MO	35/100	69/100
18	65724	Pittsburg	MO	35/100	70/100
19	63443	Hunnewell	MO	36/100	68/100
20	63736	Benton	MO	37/100	91/100
21	64624	Braymer	MO	38/100	78/100
22	63013	Beaufort	MO	39/100	81/100
23	63084	Union	MO	39/100	71/100
24	63341	Defiance	MO	40/100	53/100
25	63828	Canalou	MO	40/100	83/100
26	64735	Clinton	MO	40/100	71/100
27	64770	Montrose	MO	40/100	71/100
28	65664	Halltown	MO	40/100	79/100
29	65770	Walnut Grove	MO	40/100	76/100
30	63846	Essex	MO	41/100	92/100
31	63862	Lilbourn	MO	41/100	79/100
32	63957	Piedmont	MO	41/100	70/100
33	64856	Pineville	MO	41/100	66/100
34	63876	Senath	MO	44/100	93/100
35	64463	King City	MO	45/100	61/100
36	64661	Mercer	MO	45/100	69/100
37	64752	Hume	MO	45/100	60/100
38	64759	Lamar	MO	45/100	74/100
39	64790	Walker	MO	45/100	79/100
40	65041	Hermann	MO	45/100	57/100
41	63090	Washington	MO	47/100	72/100
42	63556	Milan	MO	47/100	82/100
43	63954	Neelyville	MO	47/100	89/100
44	63966	Wappapello	MO	47/100	79/100
45	64020	Concordia	MO	47/100	78/100
46	64461	Hopkins	MO	47/100	65/100
47	65026	Eldon	MO	47/100	77/100
48	65654	Freistatt	MO	47/100	78/100
49	65771	Walnut Shade	MO	47/100	82/100
50	65079	Sunrise Beach	MO	48/100	71/100
51	64483	Rosendale	MO	49/100	63/100
52	65801	Springfield	MO	49/100	73/100
53	65802	Springfield	MO	49/100	70/100
54	65803	Springfield	MO	49/100	75/100
55	65804	Springfield	MO	49/100	70/100
56	65805	Springfield	MO	49/100	75/100
57	65806	Springfield	MO	49/100	70/100
58	65807	Springfield	MO	49/100	70/100
59	65808	Springfield	MO	49/100	73/100
60	65809	Springfield	MO	49/100	70/100
61	65810	Springfield	MO	49/100	70/100
62	65814	Springfield	MO	49/100	73/100
63	65817	Springfield	MO	49/100	73/100
64	65890	Springfield	MO	49/100	73/100
65	65897	Springfield	MO	49/100	73/100
66	65898	Springfield	MO	49/100	73/100
67	65899	Springfield	MO	49/100	73/100
68	63005	Chesterfield	MO	50/100	51/100
69	63006	Chesterfield	MO	50/100	66/100
70	63010	Arnold	MO	50/100	55/100
71	63017	Chesterfield	MO	50/100	56/100
72	63068	New Haven	MO	50/100	77/100
73	63537	Edina	MO	50/100	71/100
74	63620	Annapolis	MO	50/100	61/100
75	63739	Burfordville	MO	50/100	76/100
76	63775	Perryville	MO	50/100	54/100
77	63867	Matthews	MO	50/100	82/100
78	63952	Mill Spring	MO	50/100	69/100
79	64067	Lexington	MO	50/100	81/100
80	64071	Mayview	MO	50/100	70/100
81	64723	Amsterdam	MO	50/100	66/100
82	64742	Drexel	MO	50/100	76/100
83	64783	Schell City	MO	50/100	81/100
84	64842	Fairview	MO	50/100	75/100
85	65335	Ionia	MO	50/100	77/100
86	65571	Summersville	MO	50/100	77/100
87	65706	Marshfield	MO	50/100	70/100
88	65723	Pierce City	MO	50/100	66/100
89	63050	Hillsboro	MO	52/100	72/100
90	63379	Troy	MO	52/100	69/100
91	63660	Mineral Point	MO	52/100	82/100
92	63874	Risco	MO	52/100	94/100
93	63933	Campbell	MO	52/100	91/100
94	64451	Forest City	MO	52/100	64/100
95	64850	Neosho	MO	52/100	72/100
96	65066	Owensville	MO	52/100	82/100
97	65327	Emma	MO	52/100	78/100
98	65550	Newburg	MO	52/100	72/100
99	65742	Rogersville	MO	52/100	82/100
100	65778	Myrtle	MO	52/100	82/100

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: 2026-06-04.

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.