2026 Rankings

Least Reliable Water Systems in Tennessee — 2026

Last updated: April 13, 2026

787 ZIP codes ranked by Reliability Score #1: ZIP 37151 (Riddleton, TN) - 15/100

Out of 787 ZIP codes with data in Tennessee, these are the lowest-ranked areas for reliability score. See also: National Least Reliable Water Systems in America | All Tennessee Rankings

Statistic Value
ZIP codes ranked 787
Lowest value 15/100
Median value 80/100
State Tennessee

100 Lowest-Ranked ZIP Codes

Rank ZIP Code City State Reliability Score Safety Score
1 37151 Riddleton TN 15/100 45/100
2 38585 Spencer TN 15/100 58/100
3 37857 Rogersville TN 18/100 54/100
4 38549 Byrdstown TN 18/100 63/100
5 37110 Mcminnville TN 25/100 53/100
6 38562 Gainesboro TN 25/100 40/100
7 37387 Tracy City TN 26/100 88/100
8 37166 Smithville TN 27/100 78/100
9 37716 Clinton TN 30/100 51/100
10 37769 Lake City TN 30/100 51/100
11 38008 Bolivar TN 30/100 82/100
12 38363 Parsons TN 30/100 71/100
13 37321 Dayton TN 34/100 88/100
14 37748 Harriman TN 34/100 57/100
15 37762 Jellico TN 35/100 81/100
16 38052 Middleton TN 35/100 91/100
17 38375 Selmer TN 35/100 70/100
18 38473 Minor Hill TN 37/100 66/100
19 38075 Whiteville TN 38/100 81/100
20 38556 Jamestown TN 38/100 78/100
21 37134 New Johnsonville TN 40/100 64/100
22 37355 Manchester TN 40/100 64/100
23 37398 Winchester TN 40/100 81/100
24 37683 Mountain City TN 40/100 66/100
25 38057 Moscow TN 40/100 74/100
26 38251 Puryear TN 40/100 92/100
27 38255 Sharon TN 40/100 87/100
28 38330 Dyer TN 40/100 81/100
29 38340 Henderson TN 40/100 77/100
30 38425 Clifton TN 40/100 49/100
31 38574 Monterey TN 40/100 68/100
32 37064 Franklin TN 41/100 43/100
33 37067 Franklin TN 41/100 53/100
34 37069 Franklin TN 41/100 43/100
35 37074 Hartsville TN 41/100 53/100
36 38049 Mason TN 42/100 94/100
37 37722 Cosby TN 43/100 71/100
38 37160 Shelbyville TN 45/100 57/100
39 37306 Belvidere TN 45/100 91/100
40 37862 Sevierville TN 45/100 74/100
41 37874 Sweetwater TN 45/100 61/100
42 37876 Sevierville TN 45/100 74/100
43 38392 Mercer TN 45/100 68/100
44 38450 Collinwood TN 45/100 66/100
45 38486 Westpoint TN 45/100 56/100
46 38575 Moss TN 46/100 72/100
47 37012 Alexandria TN 47/100 66/100
48 37801 Maryville TN 47/100 66/100
49 37803 Maryville TN 47/100 66/100
50 37804 Maryville TN 47/100 61/100
51 37356 Monteagle TN 48/100 78/100
52 37890 White Pine TN 48/100 63/100
53 38464 Lawrenceburg TN 48/100 58/100
54 37082 Kingston Springs TN 50/100 76/100
55 37096 Linden TN 50/100 51/100
56 37183 Wartrace TN 50/100 68/100
57 37324 Decherd TN 50/100 93/100
58 37327 Dunlap TN 50/100 82/100
59 37854 Rockwood TN 50/100 63/100
60 37863 Pigeon Forge TN 50/100 66/100
61 37887 Wartburg TN 50/100 93/100
62 38041 Henning TN 50/100 81/100
63 38063 Ripley TN 50/100 78/100
64 38232 Hornbeak TN 50/100 86/100
65 38242 Paris TN 50/100 88/100
66 38301 Jackson TN 50/100 54/100
67 38305 Jackson TN 50/100 54/100
68 38321 Cedar Grove TN 50/100 97/100
69 38326 Counce TN 50/100 74/100
70 38358 Milan TN 50/100 88/100
71 37030 Carthage TN 52/100 59/100
72 37385 Tellico Plains TN 52/100 69/100
73 37807 Maynardville TN 52/100 65/100
74 38220 Atwood TN 53/100 89/100
75 38501 Cookeville TN 53/100 69/100
76 38505 Cookeville TN 53/100 74/100
77 38506 Cookeville TN 53/100 69/100
78 38570 Livingston TN 53/100 79/100
79 38580 Rickman TN 53/100 79/100
80 38563 Gordonsville TN 54/100 62/100
81 37040 Clarksville TN 55/100 65/100
82 37042 Clarksville TN 55/100 65/100

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.

Explore More Rankings

How this ranking is calculated, data sources, and limitations: Rankings Methodology →


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Home Safety 2026 Water compliance, PFAS, radon, and annual AQI score inputs PFAS 2026 Forever chemicals detected in drinking water Lead Risk 2026 Lead service-line indicators and system-level action-level exceedances
Disclaimer: Rankings are based on EPA, FEMA, and federal agency data. They reflect historical patterns and risk indicators, not necessarily current conditions. For the most current information, contact your local water utility or request a Consumer Confidence Report.

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