Massachusetts Water Hardness by County
Water in Massachusetts has a median hardness of 43.7 mg/L as CaCO₃ — "soft" on the USGS scale — based on 10,226 measurements at 2,358 monitoring stations. Berkshire County has the state's hardest measured water (119.5 mg/L); Hampshire County the softest (11.5). Rank: #39 of the 50 states and D.C.
Massachusetts water hardness map — what the numbers mean. Data verified 2026-07-22.
Of Massachusetts's 12 measured counties, 4 moderately hard and 8 soft. The hardest are Berkshire County (119.5 mg/L), Essex County (79.5), and Suffolk County (79.5). Hampshire County is the softest at 11.5 mg/L (soft).
No measured Massachusetts county reaches the hard threshold, so effectively none of its residents in counties with gate-passing hardness data live in a hard-or-worse county.
Statewide, Massachusetts's median works out to 2.6 grains per gallon and ranks #39 of the 50 states and D.C. Across 10,226 measurements at 2,358 stations — 3,628 of them since 2000 — the middle 80% of readings fall between 10 and 154 mg/L. The public record runs from 1944 to 2024.
See where Massachusetts sits nationally on the national map, or what its number means on the hardness scale.
Download the Massachusetts water hardness map (PNG) — Water hardness by county in Massachusetts: 12 counties mapped from USGS/EPA data, statewide median 43.7 mg/L (soft); darker counties have harder water.
By county
Water hardness by county
The table lists all 12 measured Massachusetts counties, hardest first. Their medians span 119.5 mg/L in Berkshire County to 11.5 in Hampshire County — a 10.4× range. 2 more Massachusetts counties lack gate-passing data.
| County | Median | Band | Results | Sites | Newest |
|---|---|---|---|---|---|
| Berkshire County | 119.5 | Moderately hard | 768 | 201 | 2023 |
| Essex County | 79.5 | Moderately hard | 670 | 133 | 2024 |
| Suffolk County | 79.5 | Moderately hard | 108 | 18 | 2004 |
| Middlesex County | 64 | Moderately hard | 2,682 | 300 | 2023 |
| Norfolk County | 45 | Soft | 813 | 179 | 2021 |
| Worcester County | 41 | Soft | 1,382 | 285 | 2023 |
| Hampden County | 39.4 | Soft | 215 | 99 | 2021 |
| Bristol County | 27.8 | Soft | 299 | 69 | 2021 |
| Plymouth County | 24 | Soft | 563 | 210 | 2021 |
| Barnstable County | 22 | Soft | 1,522 | 653 | 2023 |
| Franklin County | 14.4 | Soft | 1,002 | 105 | 2023 |
| Hampshire County | 11.5 | Soft | 150 | 55 | 2017 |
ZIP codes
ZIP codes in Massachusetts
The ZIP codes below are grouped by the Massachusetts county they fall in. Each ZIP takes its county's measured median — shown in the group header — so this is a ZIP-to-county guide, not a separate reading for every ZIP. To check the water system serving a specific address, use the lookup.
Berkshire County · 119.5 mg/L · Moderately hard
01029†012010122001222†01223†01224†01225†0122601229†01230†01235†01236†01237†0123801240†0124201244†01245†0124701253†01254†01255†01256†01257†01258†01259†01260†01262†01264†01266†01267†01270†01343†
Essex County · 79.5 mg/L · Moderately hard
0181001830018320183301834†0183501840018410184301844018450186001901019020190401905019060190701908019130191501921†01922019230192901930†019370193801940019440194501949†0195001951†019520196001965019660196901970019820198301984†01985
Suffolk County · 79.5 mg/L · Moderately hard
0210802109021100211102113021140211502116021180211902120021210212202124021250212602127021280212902130021310213202133021340213502136021500215102152021630219902203022050221002215
Middlesex County · 64 mg/L · Moderately hard
01431†014320145001460014630146401469†01474†01701017020171801719†0172001721017300173101741†0174201746017480174901752017540176001770†0177301775†0177601778†018010180301821018240182601827†01850018510185201854018620186301864†018670187601879†018800188601887018900213802139021400214102142021430214402145021480214902155021760218002420024210245102452024530245802459024600246102462024640246502466024680247202474024760247802493†
Norfolk County · 45 mg/L · Soft
0201902021†020250202602030†02032020350203802052020530205402056020620206702071020720208102090020930216902170021710218402186†021880218902190021910232202343†02368024450244602457024670248102482024920249402762
Worcester County · 41 mg/L · Soft
0100501031†01037†01068†010740108301092†01094†01331†01366†01368†0142001430†0143401436014380144001451†01452†0145301462†01468†01473†014750150101503†015040150501506†01507†0151001515†01516†01518†015190152001522†01523†01524†015250152701529†01531†01532015340153501536†01537†0154001541†01542†01543†015450155001560†01561015620156401566†0156801569†01570†01571†0158101583015850158801590†016020160301604016050160601607016080160901610016110161201740†017450174701756†0175701772
Hampden County · 39.4 mg/L · Soft
0100101008†0100901010†01011†01013†01020†01022†010280103001034†01036010400105601057†01069†01071†0107701079†01080†01081†010850108901095†01097†0110301104011050110601107011080110901118011190112801129011440115101521†
Bristol County · 27.8 mg/L · Soft
0204802356023570237502702†0270302715†02717†02718†02719†02720†02721027230272402725†027260274002743†02744027450274602747†02748027600276302764027660276702769†02771†0277702779†0278002790†02791†
Plymouth County · 24 mg/L · Soft
0204302045†020470205002061020660230102302023240232502330†02332†023330233802339023410234602347†02350023510235902360†02364†02366†02367†0237002379023820253802558†025710257602738†0273902770†
Barnstable County · 22 mg/L · Soft
02532025340253602537†0254002542†025530255602559†02561†0256202563026010263002631†026320263302635026370263802639026410264202643†02644026450264602647†02648026490265002652026530265502657†026590266002663†0266402666†02667†02668†0267002671026720267302675
Franklin County · 14.4 mg/L · Soft
01054†01072†01093†0130101330†01337†01338†01339†01340†01341†0134201344†01346†01347†01349†01350†01351†01354†01355†01360†01364†01367†013700137301375†0137601378†01379†01380†
Hampshire County · 11.5 mg/L · Soft
01002010030100701012†01026†01027†01032†01033†01035†01038†01039†01050†0105301060010620106301066†01070†01073†0107501082†01084†01088†01096†01098†01243†
† 182 ZIP codes are not served by a mapped community water system — most are private-well areas. See well water hardness.
Source
Groundwater vs surface water
Massachusetts's groundwater measures harder than its surface water — 49 mg/L across 3,528 samples versus 44 across 6,199, about 1.1× harder. Wells draw from groundwater, so well owners in Massachusetts tend to see the harder number — 49 mg/L, soft. Groundwater readings there run 12.6 to 250 mg/L across the middle 80% of samples. The comparison draws on 1,641 groundwater and 697 surface-water monitoring sites; 39 readings above 2,000 mg/L were logged but held out of the medians as outliers.
Groundwater (wells)
49 mg/L as CaCO₃ · 3,528 results at 1,641 stations.
Surface water (rivers, lakes)
44 mg/L as CaCO₃ · 6,199 results at 697 stations.
Groundwater measures about 1.1× harder than surface water here.
Chemistry
Water chemistry in Massachusetts
Beyond the hardness number, Massachusetts's water carries a fuller chemical signature — here is how its measured parameters compare to national benchmarks.
TDS
151 mg/L · n=2,279
151 mg/L — below the national county median of 226.
pH
7.2 pH · n=3,560
pH 7.2 — within the EPA secondary range of 6.5–8.5, on the alkaline side.
Alkalinity
25.8 mg/L as CaCO3 · n=2,526
25.8 mg/L — modest buffering capacity.
Calcium : Magnesium
18.8 : 3.8 mg/L ≈ 4.95 : 1 · n=4,152
Calcium is about 75% of Massachusetts's hardness (18.8 mg/L Ca to 3.8 mg/L Mg), a little more calcium-rich than the national ~68% calcium share.
Parameter medians may include a small share of quality-control samples; the hardness lane is fully QC-filtered.
Aquifers
Major aquifers under Massachusetts
3 aquifer systems supply much of Massachusetts's measured groundwater.
- Early Mesozoic basin aquifers — median 140 mg/L across 33 samples at 31 sites: hard.
- New York and New England crystalline-rock aquifers — median 82 mg/L across 236 samples at 179 sites: moderately hard.
- Sand and gravel aquifers (glaciated regions) — median 41.1 mg/L across 2,502 samples at 1,001 sites: soft.
Together these systems account for 2,771 measured samples at 1,211 sites. Aquifer medians pool samples across a whole system and can mask local variation — see the national aquifer map for how these compare across states.
Trend
Hardness over time
Massachusetts's decade median moved from 31 mg/L in the 1950s to 49.5 in the 2020s. Over the series, the decade median peaked at 65.8 mg/L in the 2010s and bottomed at 13.6 in the 1980s. Decade medians reflect where and what agencies sampled in each era, not just changes in the water itself.
Scale
Where Massachusetts sits on the scale
On the USGS scale, Massachusetts's 43.7 mg/L is soft — 2.6 grains per gallon, below the 60 mg/L soft cutoff — among the softest water measured in the US.
Questions
Frequently asked questions
- Is Massachusetts's water hard?
- Massachusetts's median hardness is 43.7 mg/L as CaCO₃, "soft" on the USGS scale and below the national county median of 140 mg/L.
- Which county in Massachusetts has the hardest water?
- Berkshire County, with a median of 119.5 mg/L as CaCO₃ across 768 measurements.
- Is well water harder than city water in Massachusetts?
- Groundwater measures harder here — about 1.1× the surface water — so wells tend to run harder (groundwater 49 vs surface water 44 mg/L).
- How do I find my exact hardness in Massachusetts?
- Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.
- Is Massachusetts's water harder than the national average?
- No. Massachusetts's median of 43.7 mg/L is below the national county median of 140 mg/L; it ranks #39 of the 50 states and D.C.
Compare
States with similar hardness
Two states measure closest to Massachusetts's 43.7 mg/L: Connecticut at 42.9 mg/L and Virginia at 42 mg/L. Massachusetts measures harder than 24% of states. Browse the full ranking on the statistics page.
More: hardness scale · check your address · national statistics · the national map.
By Marko Visic, MPharm, BSc Physics. Source: USGS/EPA Water Quality Portal — 10,226 Massachusetts measurements. Data last verified . Methodology.
Cite this page: “Massachusetts Water Hardness by County.” Hard Water Map. Retrieved 2026-07-22, https://hardwatermap.com/water-hardness/massachusetts/