Water Hardness in Maine
Across 88 measured cities — with 36 more covered by labeled county-level estimates — Maine's median tap water hardness is 31.6 mg/L (1.9 gpg): soft on the USGS scale. Below: every covered city, the state's hardest and softest water, and the geology that explains it.
Data updated July 6, 2026. Sources: utility-reported water quality data and USGS/EPA Water Quality Portal samples.
Maine Cities by Hardness Category
Measured cities only — labeled county estimates never enter the category counts or the median.
| Category | Range | Measured cities | Share |
|---|---|---|---|
| Soft | 0-60 mg/L | 62 | 70.5% |
| Moderately hard | 60-120 mg/L | 18 | 20.5% |
| Hard | 120-180 mg/L | 6 | 6.8% |
| Very hard | >180 mg/L | 2 | 2.3% |
Hardest and Softest Water in Maine
Measured values only; labeled county estimates and values under active dispute never rank.
Hardest water in Maine
- Limerick — 170.0 mg/L (9.9 gpg), hard
- Burnham — 158.0 mg/L (9.2 gpg), hard
- Lisbon — 152.0 mg/L (8.9 gpg), hard
- Lisbon Falls — 152.0 mg/L (8.9 gpg), hard
- Hallowell — 143.0 mg/L (8.4 gpg), hard
Softest water in Maine
- Millinocket — 5.6 mg/L (0.3 gpg), soft
- Cape Neddick — 5.7 mg/L (0.3 gpg), soft
- York — 5.7 mg/L (0.3 gpg), soft
- York Harbor — 5.7 mg/L (0.3 gpg), soft
- Brewer — 6.2 mg/L (0.4 gpg), soft
Every Covered City in Maine
All 124 covered Maine cities, sorted by population served. "County estimate" rows are labeled context values from USGS/EPA Water Quality Portal county sampling — they never enter the median above. City names link to each city's full water quality page.
| City | Hardness (mg/L) | gpg | Category | Data |
|---|---|---|---|---|
| Portland | 8.0 | 0.5 | Soft | Utility-reported |
| South Portland | 8.0 | 0.5 | Soft | Utility-reported |
| Poland | 14.2 | 0.8 | Soft | Utility-reported |
| Saco | 14.3 | 0.8 | Soft | Utility-reported |
| Kennebunk | 59.0 | 3.5 | Soft | Utility-reported |
| West Kennebunk | 59.0 | 3.5 | Soft | Utility-reported |
| Bangor | 6.2 | 0.4 | Soft | Utility-reported |
| Lewiston | 15.7 | 0.9 | Soft | Utility-reported |
| Winslow | 28.5 | 1.7 | Soft | Utility-reported |
| Topsham | 39.3 | 2.3 | Soft | Utility-reported |
| Augusta | 136.0 | 8.0 | Hard | Utility-reported |
| Berwick | 15.5 | 0.9 | Soft | Utility-reported |
| Kittery | 21.1 | 1.2 | Soft | Utility-reported |
| Sanford | 40.3 | 2.4 | Soft | Utility-reported |
| Cape Neddick | 5.7 | 0.3 | Soft | Utility-reported |
| York | 5.7 | 0.3 | Soft | Utility-reported |
| York Harbor | 5.7 | 0.3 | Soft | Utility-reported |
| Bath | 8.6 | 0.5 | Soft | Utility-reported |
| Boothbay | 15.8 | 0.9 | Soft | Utility-reported |
| Boothbay Harbor | 15.8 | 0.9 | Soft | Utility-reported |
| Brewer | 6.2 | 0.4 | Soft | Utility-reported |
| Oxford | 31.1 | 1.8 | Soft | Utility-reported |
| Gardiner | 95.9 | 5.6 | Moderately hard | Utility-reported |
| Yarmouth | 75.6 | 4.4 | Moderately hard | Utility-reported |
| Old Town | 67.5 | 4.0 | Moderately hard | Utility-reported |
| Richmond | 7.7 | 0.5 | Soft | Computed from Ca+Mg |
| Lisbon | 152.0 | 8.9 | Hard | Utility-reported |
| Lisbon Falls | 152.0 | 8.9 | Hard | Utility-reported |
| Orono | 43.9 | 2.6 | Soft | Utility-reported |
| Anson | 7.7 | 0.5 | Soft | Computed from Ca+Mg |
| Madison | 7.7 | 0.5 | Soft | Computed from Ca+Mg |
| Millinocket | 5.6 | 0.3 | Soft | Utility-reported |
| Hampden | 67.5 | 4.0 | Moderately hard | County estimate |
| Farmington | 31.2 | 1.8 | Soft | Utility-reported |
| South Berwick | 32.2 | 1.9 | Soft | Utility-reported |
| Lincoln | 93.5 | 5.5 | Moderately hard | Utility-reported |
| Lake Arrowhead | 40.0 | 2.3 | Soft | Utility-reported |
| North Waterboro | 40.0 | 2.3 | Soft | Utility-reported |
| South Paris | 36.3 | 2.1 | Soft | Utility-reported |
| Livermore Falls | 13.3 | 0.8 | Soft | Utility-reported |
| Searsport | 50.0 | 2.9 | Soft | County estimate |
| Madawaska | 100.0 | 5.8 | Moderately hard | County estimate |
| Winthrop | 46.0 | 2.7 | Soft | County estimate |
| Oakland | 30.4 | 1.8 | Soft | Utility-reported |
| Northeast Harbor | 14.6 | 0.8 | Soft | County estimate |
| Southwest Harbor | 14.6 | 0.8 | Soft | County estimate |
| New Field | 15.5 | 0.9 | Soft | Utility-reported |
| Gray | 75.5 | 4.4 | Moderately hard | Utility-reported |
| Mexico | 4.7 | 0.3 | Soft | County estimate |
| Dexter | 67.5 | 4.0 | Moderately hard | County estimate |
| Wilton | 19.0 | 1.1 | Soft | Utility-reported |
| Sangerville | 7.3 | 0.4 | Soft | County estimate |
| Bridgton | 42.9 | 2.5 | Soft | County estimate |
| Van Buren | 100.0 | 5.8 | Moderately hard | County estimate |
| Hallowell | 143.0 | 8.4 | Hard | Utility-reported |
| East Millinocket | 51.5 | 3.0 | Soft | Utility-reported |
| Fort Fairfield | 100.0 | 5.8 | Moderately hard | County estimate |
| Norway | 61.2 | 3.6 | Moderately hard | Utility-reported |
| Wiscasset | 12.0 | 0.7 | Soft | County estimate |
| Mechanic Falls | 33.4 | 1.9 | Soft | Utility-reported |
| Damariscotta | 10.1 | 0.6 | Soft | Utility-reported |
| North Berwick | 22.8 | 1.3 | Soft | Utility-reported |
| Sabattus | 77.5 | 4.5 | Moderately hard | Utility-reported |
| Eastport | 20.1 | 1.2 | Soft | County estimate |
| Lubec | 20.1 | 1.2 | Soft | County estimate |
| Milo | 9.1 | 0.5 | Soft | Utility-reported |
| Bucksport | 15.3 | 0.9 | Soft | Utility-reported |
| Fort Kent | 100.0 | 5.8 | Moderately hard | County estimate |
| Mars Hill | 100.0 | 5.8 | Moderately hard | County estimate |
| Machias | 20.1 | 1.2 | Soft | County estimate |
| Dixfield | 4.7 | 0.3 | Soft | County estimate |
| Rangeley | 11.0 | 0.6 | Soft | County estimate |
| Brunswick | 14.5 | 0.8 | Soft | Utility-reported |
| Clinton | 118.0 | 6.9 | Moderately hard | Utility-reported |
| Pittsfield | 118.0 | 6.9 | Moderately hard | Utility-reported |
| Jackman | 54.0 | 3.2 | Soft | County estimate |
| Bingham | 54.0 | 3.2 | Soft | County estimate |
| Alfred | 24.8 | 1.4 | Soft | Utility-reported |
| Norridgewock | 54.0 | 3.2 | Soft | County estimate |
| Howland | 67.5 | 4.0 | Moderately hard | County estimate |
| Kingfield | 41.9 | 2.5 | Soft | Utility-reported |
| Gorham | 7.9 | 0.5 | Soft | Utility-reported |
| Harrison | 17.9 | 1.1 | Soft | Utility-reported |
| Winterport | 115.0 | 6.7 | Moderately hard | Utility-reported |
| Bowdoinham | 29.8 | 1.7 | Soft | Utility-reported |
| Phillips | 19.4 | 1.1 | Soft | Utility-reported |
| West Paris | 14.8 | 0.9 | Soft | Utility-reported |
| Jay | 11.0 | 0.6 | Soft | County estimate |
| Strong | 18.0 | 1.1 | Soft | Utility-reported |
| Stratton | 29.0 | 1.7 | Soft | Utility-reported |
| Biddeford | 71.0 | 4.2 | Moderately hard | Utility-reported |
| Lebanon | 49.7 | 2.9 | Soft | County estimate |
| Canton | 20.0 | 1.2 | Soft | Utility-reported |
| Farmington Falls | 11.0 | 0.6 | Soft | County estimate |
| Shapleigh | 20.7 | 1.2 | Soft | Utility-reported |
| Auburn | 88.7 | 5.2 | Moderately hard | Utility-reported |
| Vassalboro | 33.5 | 2.0 | Soft | Utility-reported |
| Burnham | 158.0 | 9.2 | Hard | Utility-reported |
| East Poland | 54.0 | 3.2 | Soft | Utility-reported |
| Embden | 42.3 | 2.5 | Soft | Utility-reported |
| Limerick | 170.0 | 9.9 | Hard | Utility-reported |
| Turner | 52.6 | 3.1 | Soft | County estimate |
| Waterville | 102.0 | 6.0 | Moderately hard | Utility-reported |
| Stockton Springs | 56.1 | 3.3 | Soft | Utility-reported |
| Benton | 120.0 | 7.0 | Moderately hard | Utility-reported |
| Casco | 80.8 | 4.7 | Moderately hard | Utility-reported |
| Durham | 52.6 | 3.1 | Soft | County estimate |
| Fairfield | 74.2 | 4.3 | Moderately hard | Utility-reported |
| Hinckley | 74.2 | 4.3 | Moderately hard | Utility-reported |
| Ellsworth | 74.4 | 4.3 | Moderately hard | Utility-reported |
| Scarborough | 32.1 | 1.9 | Soft | Utility-reported |
| Holden | 14.6 | 0.8 | Soft | County estimate |
| Hollis Center | 8.6 | 0.5 | Soft | Utility-reported |
| Lagrange | 67.5 | 4.0 | Moderately hard | County estimate |
| Newcastle | 26.5 | 1.6 | Soft | Utility-reported |
| Readfield | 46.0 | 2.7 | Soft | County estimate |
| New Harbor | 49.9 | 2.9 | Soft | Computed from Ca+Mg |
| Leeds | 52.6 | 3.1 | Soft | County estimate |
| Newport | 67.5 | 4.0 | Moderately hard | County estimate |
| Oak Hill | 185.0 | 10.8 | Very hard | Utility-reported |
| Windham | 185.0 | 10.8 | Very hard | Utility-reported |
| Dover-Foxcroft | 20.7 | 1.2 | Soft | Utility-reported |
| Freeport | 42.9 | 2.5 | Soft | County estimate |
| Castine | 14.6 | 0.8 | Soft | County estimate |
Above 120 mg/L (7 gpg), scale is usually worth treating — see our water softener guide, or size a system with the hardness calculator & converter.
The Geology Behind Maine's Water Hardness
Maine sits in the New England crystalline uplands region.
New England sits on granite, gneiss, and schist - crystalline bedrock with almost no carbonate minerals for water to dissolve. Ample rain and snowmelt move quickly through thin, glacially scoured soils into rivers and upland reservoirs without picking up much calcium or magnesium. That is why the USGS maps this region among the softest water in the country.
Maine Water Hardness FAQ
Does Maine have hard water?
On the whole, no — Maine's statewide median sits below the hard threshold, though some cities run harder. The median is 31.6 mg/L (1.9 gpg) — soft on the USGS scale, where anything above 120 mg/L (7 gpg) counts as hard. 8 of Maine's 88 measured cities fall in the hard or very hard bands (9%), so check your own city rather than the state average.
How hard is tap water in Maine?
Across the 88 Maine cities with measured values in our index, the median hardness is 31.6 mg/L (1.9 gpg) — soft on the USGS scale. Individual cities range from 5.6 to 185.0 mg/L, so check your own city rather than assuming the state number.
Which city in Maine has the hardest water?
Limerick has the hardest measured tap water in our Maine index at 170.0 mg/L (9.9 gpg) — hard on the USGS scale. Rankings use measured utility values only; labeled county estimates and values under active dispute are excluded.
Do I need a water softener in Maine?
8 of Maine's 88 measured cities (9%) fall in the hard or very hard bands — above 120 mg/L (7 gpg), the level where most water treatment professionals suggest considering an ion-exchange softener. Hardness varies utility to utility, so look up your own city's value before sizing equipment.
How do I find my city's exact water hardness?
Enter your ZIP code in our free lookup at tapwaterdata.com/zip to see the value we hold for your Maine city from utility-reported water quality data, check your water utility's annual Consumer Confidence Report (CCR), or use a home test-strip kit.
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