Least Reliable Water Systems in Missouri — 2026

Out of 1,161 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	1,161
Lowest value	10/100
Median value	75/100
State	Missouri

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	63377	Silex	MO	10/100	48/100
2	63653	Leadwood	MO	15/100	58/100
3	64725	Archie	MO	18/100	61/100
4	63341	Defiance	MO	20/100	53/100
5	63824	Blodgett	MO	20/100	86/100
6	63443	Hunnewell	MO	21/100	68/100
7	63820	Anniston	MO	24/100	88/100
8	63353	Louisiana	MO	25/100	56/100
9	63456	Monroe City	MO	25/100	58/100
10	63555	Memphis	MO	25/100	69/100
11	63650	Ironton	MO	25/100	48/100
12	63654	Lesterville	MO	25/100	64/100
13	65712	Mount Vernon	MO	25/100	78/100
14	63870	Parma	MO	26/100	92/100
15	63736	Benton	MO	27/100	91/100
16	63740	Chaffee	MO	27/100	74/100
17	63640	Farmington	MO	30/100	68/100
18	64469	Maysville	MO	30/100	72/100
19	64735	Clinton	MO	30/100	71/100
20	64770	Montrose	MO	30/100	71/100
21	63862	Lilbourn	MO	31/100	79/100
22	63957	Piedmont	MO	31/100	70/100
23	63954	Neelyville	MO	32/100	89/100
24	65771	Walnut Shade	MO	32/100	82/100
25	63013	Beaufort	MO	34/100	81/100
26	64463	King City	MO	35/100	61/100
27	64661	Mercer	MO	35/100	69/100
28	65335	Ionia	MO	35/100	77/100
29	65724	Pittsburg	MO	35/100	70/100
30	63556	Milan	MO	37/100	82/100
31	64020	Concordia	MO	37/100	78/100
32	64451	Forest City	MO	37/100	64/100
33	64461	Hopkins	MO	37/100	65/100
34	65026	Eldon	MO	37/100	77/100
35	64624	Braymer	MO	38/100	78/100
36	65079	Sunrise Beach	MO	38/100	71/100
37	63084	Union	MO	39/100	71/100
38	65034	Fortuna	MO	39/100	81/100
39	65802	Springfield	MO	39/100	70/100
40	65803	Springfield	MO	39/100	75/100
41	65804	Springfield	MO	39/100	70/100
42	65806	Springfield	MO	39/100	70/100
43	65807	Springfield	MO	39/100	70/100
44	65809	Springfield	MO	39/100	70/100
45	65810	Springfield	MO	39/100	70/100
46	65897	Springfield	MO	39/100	73/100
47	63537	Edina	MO	40/100	71/100
48	63775	Perryville	MO	40/100	54/100
49	63828	Canalou	MO	40/100	83/100
50	63867	Matthews	MO	40/100	82/100
51	63952	Mill Spring	MO	40/100	69/100
52	64723	Amsterdam	MO	40/100	66/100
53	64726	Blairstown	MO	40/100	79/100
54	64742	Drexel	MO	40/100	76/100
55	64752	Hume	MO	40/100	60/100
56	65571	Summersville	MO	40/100	77/100
57	65664	Halltown	MO	40/100	79/100
58	65770	Walnut Grove	MO	40/100	76/100
59	64856	Pineville	MO	41/100	66/100
60	63379	Troy	MO	42/100	69/100
61	63874	Risco	MO	42/100	94/100
62	64850	Neosho	MO	42/100	72/100
63	65066	Owensville	MO	42/100	82/100
64	64734	Cleveland	MO	43/100	57/100
65	63016	Cedar Hill	MO	44/100	63/100
66	63876	Senath	MO	44/100	93/100
67	63935	Doniphan	MO	44/100	60/100
68	63334	Bowling Green	MO	45/100	74/100
69	63348	Foristell	MO	45/100	79/100
70	63390	Wright City	MO	45/100	72/100
71	63620	Annapolis	MO	45/100	61/100
72	63739	Burfordville	MO	45/100	76/100
73	63780	Scott City	MO	45/100	81/100
74	63784	Vanduser	MO	45/100	85/100
75	64071	Mayview	MO	45/100	70/100
76	64089	Smithville	MO	45/100	56/100
77	64421	Amazonia	MO	45/100	58/100
78	64431	Clearmont	MO	45/100	68/100
79	64486	Sheridan	MO	45/100	81/100
80	64622	Bogard	MO	45/100	81/100
81	64730	Butler	MO	45/100	74/100
82	64759	Lamar	MO	45/100	74/100
83	64783	Schell City	MO	45/100	81/100
84	65041	Hermann	MO	45/100	57/100
85	65065	Osage Beach	MO	45/100	74/100
86	65588	Winona	MO	45/100	79/100
87	65624	Cape Fair	MO	45/100	81/100
88	65760	Tecumseh	MO	45/100	81/100
89	63846	Essex	MO	46/100	92/100
90	64642	Gilman City	MO	46/100	79/100

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.