Least Reliable Water Systems in Maine — 2026

Out of 485 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	485
Lowest value	10/100
Median value	75/100
State	Maine

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	04071	Raymond	ME	10/100	43/100
2	04664	Sullivan	ME	10/100	33/100
3	04677	Sorrento	ME	10/100	33/100
4	04414	Brownville	ME	15/100	49/100
5	04863	Vinalhaven	ME	15/100	58/100
6	04496	Winterport	ME	20/100	66/100
7	04640	Hancock	ME	20/100	45/100
8	04988	Unity	ME	20/100	58/100
9	04605	Ellsworth	ME	25/100	55/100
10	04649	Jonesport	ME	25/100	59/100
11	04684	Surry	ME	25/100	56/100
12	04901	Waterville	ME	25/100	38/100
13	04464	Monson	ME	26/100	51/100
14	04578	Wiscasset	ME	30/100	56/100
15	04758	Mars Hill	ME	30/100	51/100
16	04238	Hebron	ME	35/100	48/100
17	04282	Turner	ME	35/100	56/100
18	04419	Carmel	ME	35/100	51/100
19	04843	Camden	ME	35/100	69/100
20	04856	Rockport	ME	35/100	75/100
21	04350	Litchfield	ME	38/100	63/100
22	04937	Fairfield	ME	39/100	58/100
23	04967	Pittsfield	ME	39/100	57/100
24	04040	Harrison	ME	40/100	64/100
25	04090	Wells	ME	40/100	45/100
26	04422	Charleston	ME	40/100	55/100
27	04424	Danforth	ME	40/100	79/100
28	04652	Lubec	ME	40/100	77/100
29	04658	Milbridge	ME	40/100	79/100
30	04681	Stonington	ME	40/100	62/100
31	04693	Winter Harbor	ME	40/100	60/100
32	04429	Holden	ME	41/100	67/100
33	04614	Blue Hill	ME	41/100	42/100
34	04634	Franklin	ME	41/100	62/100
35	04421	Castine	ME	42/100	66/100
36	04274	Poland	ME	43/100	30/100
37	04769	Presque Isle	ME	44/100	60/100
38	04009	Bridgton	ME	45/100	56/100
39	04037	Fryeburg	ME	45/100	46/100
40	04401	Bangor	ME	45/100	52/100
41	04443	Guilford	ME	45/100	52/100
42	04628	Dennysville	ME	45/100	81/100
43	04743	Fort Kent	ME	45/100	46/100
44	04854	Owls Head	ME	45/100	71/100
45	04947	Kingfield	ME	45/100	54/100
46	04668	Princeton	ME	46/100	79/100
47	04750	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	04074	Scarborough	ME	50/100	54/100
54	04079	Harpswell	ME	50/100	57/100
55	04210	Auburn	ME	50/100	49/100
56	04220	Buckfield	ME	50/100	46/100
57	04427	Corinth	ME	50/100	60/100
58	04530	Bath	ME	50/100	76/100
59	04660	Mount Desert	ME	50/100	57/100
60	04662	Northeast Harbor	ME	50/100	61/100
61	04922	Burnham	ME	50/100	72/100
62	04101	Portland	ME	51/100	62/100
63	04102	Portland	ME	51/100	62/100
64	04103	Portland	ME	51/100	62/100
65	04109	Portland	ME	51/100	67/100
66	04221	Canton	ME	52/100	59/100
67	04539	Bristol	ME	52/100	69/100
68	04740	Easton	ME	52/100	63/100
69	04042	Hollis Center	ME	53/100	68/100
70	04630	East Machias	ME	53/100	81/100
71	04254	Livermore Falls	ME	54/100	50/100
72	04289	West Paris	ME	54/100	68/100
73	04915	Belfast	ME	54/100	76/100
74	04011	Brunswick	ME	55/100	57/100
75	04086	Topsham	ME	55/100	75/100
76	04236	Greene	ME	55/100	66/100
77	04263	Leeds	ME	55/100	68/100
78	04416	Bucksport	ME	55/100	62/100
79	04450	Kenduskeag	ME	55/100	67/100
80	04655	Machiasport	ME	55/100	76/100
81	04666	Pembroke	ME	55/100	78/100
82	04679	Southwest Harbor	ME	55/100	65/100
83	04745	Frenchville	ME	55/100	60/100
84	04849	Lincolnville	ME	55/100	72/100
85	04944	Hinckley	ME	55/100	56/100
86	04969	Plymouth	ME	55/100	64/100

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.