Is Vermont's water hard?

Vermont's median hardness is 46.5 mg/L as CaCO₃, "soft" on the USGS scale and below the national county median of 140 mg/L.

Which county in Vermont has the hardest water?

Chittenden County, with a median of 109 mg/L as CaCO₃ across 801 measurements.

Is well water harder than city water in Vermont?

Groundwater measures harder here — about 2.4× the surface water — so wells tend to run harder (groundwater 109 vs surface water 46 mg/L).

How do I find my exact hardness in Vermont?

Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.

Is Vermont's water harder than the national average?

No. Vermont's median of 46.5 mg/L is below the national county median of 140 mg/L; it ranks #38 of the 50 states and D.C.

Vermont Water Hardness by County

Name: Water hardness by county in Vermont
Creator: Hard Water Map
License: https://creativecommons.org/licenses/by/4.0/

Water in Vermont has a median hardness of 46.5 mg/L as CaCO₃ — "soft" on the USGS scale — based on 10,998 measurements at 2,531 monitoring stations. Chittenden County has the state's hardest measured water (109 mg/L); Bennington County the softest (4.5). Rank: #38 of the 50 states and D.C.

Vermont water hardness map — what the numbers mean. Data verified 2026-07-22.

Of Vermont's 13 measured counties, 5 moderately hard and 8 soft. The hardest are Chittenden County (109 mg/L), Orange County (82.3), and Caledonia County (69.2). Bennington County is the softest at 4.5 mg/L (soft).

No measured Vermont 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, Vermont's median works out to 2.7 grains per gallon and ranks #38 of the 50 states and D.C. Across 10,998 measurements at 2,531 stations — 9,786 of them since 2000 — the middle 80% of readings fall between 4.8 and 144 mg/L. The public record runs from 1952 to 2025.

See where Vermont sits nationally on the national map, or what its number means on the hardness scale.

Download the Vermont water hardness map (PNG) — Water hardness by county in Vermont: 13 counties mapped from USGS/EPA data, statewide median 46.5 mg/L (soft); darker counties have harder water.

By county

Water hardness by county

The table lists all 13 measured Vermont counties, hardest first. Their medians span 109 mg/L in Chittenden County to 4.5 in Bennington County — a 24.2× range. 1 more Vermont county lacks gate-passing data.

County water hardness, hardest first — median mg/L as CaCO₃.
County	Median	Band	Results	Sites	Newest
Chittenden County	109	Moderately hard	801	230	2025
Orange County	82.3	Moderately hard	768	197	2025
Caledonia County	69.2	Moderately hard	1,468	204	2025
Rutland County	65.8	Moderately hard	888	266	2025
Addison County	62	Moderately hard	438	122	2025
Washington County	56.5	Soft	588	188	2025
Orleans County	55.5	Soft	1,182	189	2025
Franklin County	45.2	Soft	946	178	2025
Windsor County	33.4	Soft	914	261	2025
Essex County	13.4	Soft	528	144	2025
Lamoille County	13.3	Soft	594	125	2025
Windham County	5.2	Soft	969	219	2025
Bennington County	4.5	Soft	910	204	2025

ZIP codes

ZIP codes in Vermont

The ZIP codes below are grouped by the Vermont 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.

Chittenden County · 109 mg/L · Moderately hard

0540105403054040540505408†0543905445†05446†05452†05461†05462†0546505468†05477†0548205489†05494†05495†

Orange County · 82.3 mg/L · Moderately hard

05033†05036†05038†05039†05040†05041†05043†05045†05051†05058†05060†05061†05069†05070†05072†05075†05076†05077†05079†05081†05083†05086†05649†0565405675†05679†

Caledonia County · 69.2 mg/L · Moderately hard

05042†05046†0505005819†05821†05828†0583205836†05843†0585005851†05862†05866†05867†05871†05873†

Rutland County · 65.8 mg/L · Moderately hard

05701†05730†05731†05732†0573305735†0573605737†05738†05739†05742†05743†05744†05751†05757†05758†05759†05761†05762†05763†05764†0576505773†05774†05775†05777†

Addison County · 62 mg/L · Moderately hard

05443†05456†05472†05473†05487†05491†0573405747†05748†0575305760†05766†05769†0577005778†

Washington County · 56.5 mg/L · Soft

05602†05640†05641†05647†05648†05650†05651†05658†05660†05663†0566405666†05667†05669†05670†05673†05674†05676†05677†0567805681†05682†

Orleans County · 55.5 mg/L · Soft

05820†05822†05825†05826†05827†05829†05830†05833†05839†05841†05842†05845†05847†05853†05855†05857†05859†05860†05868†05872†05874†05875†

Franklin County · 45.2 mg/L · Soft

05441†05447†05448†05450†05454†05455†05457†05459†05471†05476†05478†05481†054830548505488

Windsor County · 33.4 mg/L · Soft

05001†0500905030†0503105032†05034†05035†05037†05048†0505205053†05055†05056†0505905062†05065†05067†05068†05071†05073†05084†0508805089†05091†05142†05143†051490515005151†05153†0515605161†05746†05767†05772†

Essex County · 13.4 mg/L · Soft

05824†05837†05840†05846†05858†05901†0590205903†05904†05905†05906†05907†

Lamoille County · 13.3 mg/L · Soft

05442†0544405464†05492†05652†05653†05655†05656†05661†0567205680†

Windham County · 5.2 mg/L · Soft

05101†05141†05146†05148†05154†05155†05158†05301†05341†05342†05343†05344†05345†05346†05351†05353†05354†05355†05356†05358†05359†05360†05361†05362†05363†

Bennington County · 4.5 mg/L · Soft

05152†05201†0525005251†05252†05253052540525505257†05260†05261†05262†05340†05350†05352†05768†05776†

† 223 ZIP codes are not served by a mapped community water system — most are private-well areas. See well water hardness.

Check any ZIP's utility and hardness →

Source

Groundwater vs surface water

Vermont's groundwater measures harder than its surface water — 109 mg/L across 110 samples versus 46 across 10,887, about 2.4× harder. Wells draw from groundwater, so well owners in Vermont tend to see the harder number — 109 mg/L, moderately hard. Groundwater readings there run 59.3 to 231 mg/L across the middle 80% of samples. The comparison draws on 89 groundwater and 2,441 surface-water monitoring sites.

Groundwater (wells)

109 mg/L as CaCO₃ · 110 results at 89 stations.

Surface water (rivers, lakes)

46 mg/L as CaCO₃ · 10,887 results at 2,441 stations.

Groundwater measures about 2.4× harder than surface water here.

Chemistry

Water chemistry in Vermont

Beyond the hardness number, Vermont's water carries a fuller chemical signature — here is how its measured parameters compare to national benchmarks.

TDS

156 mg/L · n=59

156 mg/L — below the national county median of 226.

pH

7.7 pH · n=56,358

pH 7.7 — within the EPA secondary range of 6.5–8.5, on the alkaline side.

Alkalinity

42.4 mg/L as CaCO3 · n=11,842

42.4 mg/L — modest buffering capacity.

Calcium : Magnesium

14.6 : 2.1 mg/L ≈ 6.95 : 1 · n=12,868

Calcium is about 81% of Vermont's hardness (14.6 mg/L Ca to 2.1 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 Vermont

One aquifer system supply much of Vermont's measured groundwater.

Sand and gravel aquifers (glaciated regions) — median 110 mg/L across 61 samples at 44 sites: moderately hard.

Together these systems account for 61 measured samples at 44 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

Vermont's decade median moved from 43 mg/L in the 1950s to 45.6 in the 2020s. Over the series, the decade median peaked at 64.5 mg/L in the 1980s and bottomed at 39.3 in the 2010s. Decade medians reflect where and what agencies sampled in each era, not just changes in the water itself.

Scale

Where Vermont sits on the scale

On the USGS scale, Vermont's 46.5 mg/L is soft — 2.7 grains per gallon, below the 60 mg/L soft cutoff — among the softest water measured in the US.

Harder than 25% of the 2,977 measured county medians.

Questions

Frequently asked questions

Is Vermont's water hard?: Vermont's median hardness is 46.5 mg/L as CaCO₃, "soft" on the USGS scale and below the national county median of 140 mg/L.
Which county in Vermont has the hardest water?: Chittenden County, with a median of 109 mg/L as CaCO₃ across 801 measurements.
Is well water harder than city water in Vermont?: Groundwater measures harder here — about 2.4× the surface water — so wells tend to run harder (groundwater 109 vs surface water 46 mg/L).
How do I find my exact hardness in Vermont?: Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.
Is Vermont's water harder than the national average?: No. Vermont's median of 46.5 mg/L is below the national county median of 140 mg/L; it ranks #38 of the 50 states and D.C.

Compare

States with similar hardness

Two states measure closest to Vermont's 46.5 mg/L: Oregon at 48.1 mg/L and Alabama at 48.4 mg/L. Vermont measures harder than 26% 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 — 10,998 Vermont measurements. Data last verified 2026-07-22. Methodology.

Cite this page: “Vermont Water Hardness by County.” Hard Water Map. Retrieved 2026-07-22, https://hardwatermap.com/water-hardness/vermont/