Least Reliable Water Systems in Maine — 2026

Out of 504 ZIP codes with data in Maine, these are the lowest-ranked areas for reliability score. See also: National Least Reliable Water Systems in America | All Maine Rankings

Statistic	Value
ZIP codes ranked	504
Lowest value	10/100
Median value	65/100
State	Maine

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	04664	Sullivan	ME	10/100	33/100
2	04677	Sorrento	ME	10/100	33/100
3	04414	Brownville	ME	15/100	49/100
4	04863	Vinalhaven	ME	15/100	58/100
5	04496	Winterport	ME	20/100	66/100
6	04640	Hancock	ME	20/100	45/100
7	04988	Unity	ME	20/100	58/100
8	04605	Ellsworth	ME	25/100	55/100
9	04649	Jonesport	ME	25/100	59/100
10	04684	Surry	ME	25/100	56/100
11	04464	Monson	ME	26/100	51/100
12	04071	Raymond	ME	30/100	43/100
13	04578	Wiscasset	ME	30/100	56/100
14	04758	Mars Hill	ME	30/100	51/100
15	04238	Hebron	ME	35/100	48/100
16	04282	Turner	ME	35/100	56/100
17	04419	Carmel	ME	35/100	51/100
18	04901	Waterville	ME	35/100	38/100
19	04903	Waterville	ME	35/100	39/100
20	04350	Litchfield	ME	38/100	63/100
21	04937	Fairfield	ME	39/100	58/100
22	04967	Pittsfield	ME	39/100	57/100
23	04040	Harrison	ME	40/100	64/100
24	04422	Charleston	ME	40/100	55/100
25	04424	Danforth	ME	40/100	79/100
26	04652	Lubec	ME	40/100	77/100
27	04658	Milbridge	ME	40/100	79/100
28	04681	Stonington	ME	40/100	62/100
29	04693	Winter Harbor	ME	40/100	60/100
30	04429	Holden	ME	41/100	67/100
31	04614	Blue Hill	ME	41/100	42/100
32	04634	Franklin	ME	41/100	62/100
33	04420	Castine	ME	42/100	61/100
34	04421	Castine	ME	42/100	66/100
35	04230	East Poland	ME	43/100	57/100
36	04274	Poland	ME	43/100	30/100
37	04009	Bridgton	ME	45/100	56/100
38	04037	Fryeburg	ME	45/100	46/100
39	04090	Wells	ME	45/100	45/100
40	04401	Bangor	ME	45/100	52/100
41	04402	Bangor	ME	45/100	57/100
42	04743	Fort Kent	ME	45/100	46/100
43	04854	Owls Head	ME	45/100	71/100
44	04947	Kingfield	ME	45/100	54/100
45	04668	Princeton	ME	46/100	79/100
46	04750	Limestone	ME	46/100	59/100
47	04751	Limestone	ME	46/100	59/100
48	04250	Lisbon	ME	47/100	63/100
49	04239	Jay	ME	48/100	61/100
50	04055	Naples	ME	49/100	38/100
51	04093	Buxton	ME	49/100	60/100
52	04280	Sabattus	ME	49/100	65/100
53	04070	Scarborough	ME	50/100	60/100
54	04074	Scarborough	ME	50/100	54/100
55	04079	Harpswell	ME	50/100	57/100
56	04220	Buckfield	ME	50/100	46/100
57	04427	Corinth	ME	50/100	60/100
58	04443	Guilford	ME	50/100	52/100
59	04628	Dennysville	ME	50/100	81/100
60	04660	Mount Desert	ME	50/100	57/100
61	04662	Northeast Harbor	ME	50/100	61/100
62	04843	Camden	ME	50/100	69/100
63	04856	Rockport	ME	50/100	75/100
64	04922	Burnham	ME	50/100	72/100
65	04101	Portland	ME	51/100	62/100
66	04102	Portland	ME	51/100	62/100
67	04103	Portland	ME	51/100	62/100
68	04104	Portland	ME	51/100	67/100
69	04109	Portland	ME	51/100	67/100
70	04112	Portland	ME	51/100	62/100
71	04122	Portland	ME	51/100	62/100
72	04123	Portland	ME	51/100	62/100
73	04124	Portland	ME	51/100	62/100
74	04539	Bristol	ME	52/100	69/100
75	04042	Hollis Center	ME	53/100	68/100
76	04630	East Machias	ME	53/100	81/100
77	04254	Livermore Falls	ME	54/100	50/100
78	04289	West Paris	ME	54/100	68/100
79	04769	Presque Isle	ME	54/100	60/100
80	04915	Belfast	ME	54/100	76/100
81	04011	Brunswick	ME	55/100	57/100
82	04236	Greene	ME	55/100	66/100
83	04263	Leeds	ME	55/100	68/100
84	04416	Bucksport	ME	55/100	62/100
85	04450	Kenduskeag	ME	55/100	67/100
86	04655	Machiasport	ME	55/100	76/100
87	04666	Pembroke	ME	55/100	78/100
88	04679	Southwest Harbor	ME	55/100	65/100
89	04745	Frenchville	ME	55/100	60/100
90	04849	Lincolnville	ME	55/100	72/100
91	04940	Farmington Falls	ME	55/100	64/100
92	04944	Hinckley	ME	55/100	56/100
93	04969	Plymouth	ME	55/100	64/100
94	03901	Berwick	ME	57/100	59/100
95	04221	Canton	ME	57/100	59/100
96	04463	Milo	ME	57/100	61/100
97	04479	Sangerville	ME	57/100	65/100
98	04572	Waldoboro	ME	57/100	66/100
99	04740	Easton	ME	57/100	63/100
100	04742	Fort Fairfield	ME	57/100	59/100

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.