Water Hardness in Maryland
Across 118 measured cities — with 89 more covered by labeled county-level estimates — Maryland's median tap water hardness is 117.0 mg/L (6.8 gpg): moderately hard 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.
Maryland 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 | 7 | 5.9% |
| Moderately hard | 60-120 mg/L | 107 | 90.7% |
| Hard | 120-180 mg/L | 4 | 3.4% |
| Very hard | >180 mg/L | 0 | 0.0% |
Hardest and Softest Water in Maryland
Measured values only; labeled county estimates and values under active dispute never rank.
Hardest water in Maryland
- Urbana — 132.0 mg/L (7.7 gpg), hard
- Mount Airy — 131.0 mg/L (7.7 gpg), hard
- Chesapeake Beach — 130.0 mg/L (7.6 gpg), hard
- North Beach — 130.0 mg/L (7.6 gpg), hard
- Rockville — 118.8 mg/L (7.0 gpg), moderately hard
Softest water in Maryland
- Fort George Meade — 2.2 mg/L (0.1 gpg), soft
- Fort Meade — 3.5 mg/L (0.2 gpg), soft
- Easton — 23.6 mg/L (1.4 gpg), soft
- Cockeysville — 26.9 mg/L (1.6 gpg), soft
- Severn — 29.9 mg/L (1.8 gpg), soft
Every Covered City in Maryland
All 207 covered Maryland 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 |
|---|---|---|---|---|
| Takoma Park | 110.2 | 6.4 | Moderately hard | Utility-reported |
| Baltimore | 169.0 | 9.9 | Hard | County estimate |
| Rockville | 118.8 | 7.0 | Moderately hard | Utility-reported |
| College Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Adelphi | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Ashton-Sandy Spring | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Aspen Hill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Beltsville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Berwyn Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Bethesda | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Bladensburg | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Brentwood | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Brookeville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Brookmont | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Burnt Mills | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Burtonsville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Cabin John | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Calverton | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Capitol Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Cedar Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Cheverly | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chevy Chase | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chevy Chase Section Five | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chevy Chase Section Three | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chevy Chase View | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chevy Chase Village | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Chillum | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Cloverly | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Colesville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Colmar Manor | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Coral Hills | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Cottage City | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Darnestown | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Derwood | 117.0 | 6.8 | Moderately hard | Utility-reported |
| District Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| East Riverdale | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Edmonston | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Fairland | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Fairmount Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Forest Glen | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Forest Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Four Corners | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Friendship Heights Village | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Gaithersburg | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Garrett Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Glassmanor | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Glen Echo | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Glenarden | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Glenmont | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Greenbelt | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Hillandale | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Hillcrest Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Hyattsville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Kemp Mill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Kensington | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Konterra | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Landover | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Landover Hills | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Langley Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Lanham | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Laurel | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Layhill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Leisure World | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Marlow Heights | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Martin's Additions | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Maryland Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Mount Rainier | 117.0 | 6.8 | Moderately hard | Utility-reported |
| National Harbor | 117.0 | 6.8 | Moderately hard | Utility-reported |
| New Carrollton | 117.0 | 6.8 | Moderately hard | Utility-reported |
| North Bethesda | 117.0 | 6.8 | Moderately hard | Utility-reported |
| North Brentwood | 117.0 | 6.8 | Moderately hard | Utility-reported |
| North Chevy Chase | 117.0 | 6.8 | Moderately hard | Utility-reported |
| North Kensington | 117.0 | 6.8 | Moderately hard | Utility-reported |
| North Potomac | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Olney | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Oxon Hill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Peppermill Village | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Potomac | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Redland | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Riverdale Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Seabrook | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Seat Pleasant | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Silver Hill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Silver Spring | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Somerset | 117.0 | 6.8 | Moderately hard | Utility-reported |
| South Kensington | 117.0 | 6.8 | Moderately hard | Utility-reported |
| South Laurel | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Spencerville | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Springdale | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Suitland | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Summerfield | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Temple Hills | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Travilah | 117.0 | 6.8 | Moderately hard | Utility-reported |
| University Park | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Walker Mill | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Washington Grove | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Wheaton | 117.0 | 6.8 | Moderately hard | Utility-reported |
| White Oak | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Woodlawn | 117.0 | 6.8 | Moderately hard | Utility-reported |
| Severna Park | 34.6 | 2.0 | Soft | Utility-reported |
| Columbia | 73.8 | 4.3 | Moderately hard | Utility-reported |
| Bel Air South | 81.0 | 4.7 | Moderately hard | Utility-reported |
| Abingdon | 80.9 | 4.7 | Moderately hard | County estimate |
| Bel Air | 81.0 | 4.7 | Moderately hard | Utility-reported |
| Hagerstown | 126.0 | 7.4 | Hard | County estimate |
| Funkstown | 126.0 | 7.4 | Hard | County estimate |
| Lexington Park | 5.7 | 0.3 | Soft | County estimate |
| Fort Meade | 3.5 | 0.2 | Soft | Utility-reported |
| Odenton | 77.1 | 4.5 | Moderately hard | County estimate |
| Frederick | 105.0 | 6.1 | Moderately hard | Utility-reported |
| Fort George Meade | 2.2 | 0.1 | Soft | Utility-reported |
| Urbana | 132.0 | 7.7 | Hard | Utility-reported |
| Aberdeen | 80.9 | 4.7 | Moderately hard | County estimate |
| California | 5.7 | 0.3 | Soft | County estimate |
| Salisbury | 32.3 | 1.9 | Soft | Utility-reported |
| Bowie | 78.1 | 4.6 | Moderately hard | Utility-reported |
| Fairwood | 78.1 | 4.6 | Moderately hard | Utility-reported |
| Sykesville | 62.0 | 3.6 | Moderately hard | County estimate |
| Westminster | 62.0 | 3.6 | Moderately hard | County estimate |
| Patuxent River | 5.7 | 0.3 | Soft | County estimate |
| Easton | 23.6 | 1.4 | Soft | Utility-reported |
| Havre de Grace | 80.9 | 4.7 | Moderately hard | County estimate |
| Cambridge | 57.1 | 3.3 | Soft | County estimate |
| Elkton | 94.0 | 5.5 | Moderately hard | County estimate |
| Severn | 29.9 | 1.8 | Soft | Utility-reported |
| La Plata | 30.6 | 1.8 | Soft | County estimate |
| Mount Airy | 131.0 | 7.7 | Hard | Utility-reported |
| Lusby | 127.0 | 7.4 | Hard | County estimate |
| Dunkirk | 127.0 | 7.4 | Hard | County estimate |
| North East | 94.0 | 5.5 | Moderately hard | County estimate |
| Walkersville | 64.8 | 3.8 | Moderately hard | County estimate |
| Ocean City | 52.5 | 3.1 | Soft | County estimate |
| North Beach | 130.0 | 7.6 | Hard | Utility-reported |
| Perryville | 94.0 | 5.5 | Moderately hard | County estimate |
| Aberdeen Proving Ground | 80.9 | 4.7 | Moderately hard | County estimate |
| Fruitland | 30.7 | 1.8 | Soft | County estimate |
| Cockeysville | 26.9 | 1.6 | Soft | Utility-reported |
| Brunswick | 84.2 | 4.9 | Moderately hard | Utility-reported |
| Chestertown | 60.6 | 3.5 | Moderately hard | County estimate |
| Poolesville | 84.2 | 4.9 | Moderately hard | Utility-reported |
| Chesapeake Beach | 130.0 | 7.6 | Hard | Utility-reported |
| Berlin | 52.5 | 3.1 | Soft | County estimate |
| Prince Frederick | 127.0 | 7.4 | Hard | County estimate |
| Pocomoke City | 52.5 | 3.1 | Soft | County estimate |
| Solomons | 127.0 | 7.4 | Hard | County estimate |
| Charlestown | 94.0 | 5.5 | Moderately hard | County estimate |
| Williamsport | 126.0 | 7.4 | Hard | County estimate |
| Snow Hill | 52.5 | 3.1 | Soft | County estimate |
| St. Michaels | 44.0 | 2.6 | Soft | County estimate |
| Centreville | 58.5 | 3.4 | Soft | County estimate |
| Princess Anne | 39.7 | 2.3 | Soft | County estimate |
| Leonardtown | 5.7 | 0.3 | Soft | County estimate |
| Cumberland | 72.5 | 4.2 | Moderately hard | County estimate |
| Millersville | 77.1 | 4.5 | Moderately hard | County estimate |
| Smithsburg | 126.0 | 7.4 | Hard | County estimate |
| Federalsburg | 40.8 | 2.4 | Soft | County estimate |
| Stevensville | 58.5 | 3.4 | Soft | County estimate |
| Emmitsburg | 64.8 | 3.8 | Moderately hard | County estimate |
| Westernport | 89.4 | 5.2 | Moderately hard | County estimate |
| Hurlock | 57.1 | 3.3 | Soft | County estimate |
| Perry Point | 94.0 | 5.5 | Moderately hard | County estimate |
| Hancock | 126.0 | 7.4 | Hard | County estimate |
| Greensboro | 40.8 | 2.4 | Soft | County estimate |
| Rock Hall | 60.6 | 3.5 | Moderately hard | County estimate |
| Ridgely | 40.8 | 2.4 | Soft | County estimate |
| Myersville | 64.8 | 3.8 | Moderately hard | County estimate |
| Pittsville | 30.7 | 1.8 | Soft | County estimate |
| Trappe | 44.0 | 2.6 | Soft | County estimate |
| Grasonville | 58.5 | 3.4 | Soft | County estimate |
| New Windsor | 62.0 | 3.6 | Moderately hard | County estimate |
| Hebron | 30.7 | 1.8 | Soft | County estimate |
| Oakland | 89.4 | 5.2 | Moderately hard | County estimate |
| Willards | 30.7 | 1.8 | Soft | County estimate |
| Denton | 40.8 | 2.4 | Soft | County estimate |
| Savage | 60.1 | 3.5 | Moderately hard | County estimate |
| Crofton | 77.1 | 4.5 | Moderately hard | County estimate |
| Oxford | 44.0 | 2.6 | Soft | County estimate |
| Queenstown | 58.5 | 3.4 | Soft | County estimate |
| Preston | 40.8 | 2.4 | Soft | County estimate |
| Chesapeake City | 94.0 | 5.5 | Moderately hard | County estimate |
| Lothian | 77.1 | 4.5 | Moderately hard | County estimate |
| Secretary | 57.1 | 3.3 | Soft | County estimate |
| East New Market | 57.1 | 3.3 | Soft | County estimate |
| Kitzmiller | 89.4 | 5.2 | Moderately hard | County estimate |
| St. Leonard | 127.0 | 7.4 | Hard | County estimate |
| Huntingtown | 127.0 | 7.4 | Hard | County estimate |
| Accident | 89.4 | 5.2 | Moderately hard | County estimate |
| Delmar | 30.7 | 1.8 | Soft | County estimate |
| Conowingo | 94.0 | 5.5 | Moderately hard | County estimate |
| St. James | 126.0 | 7.4 | Hard | County estimate |
| Port Deposit | 94.0 | 5.5 | Moderately hard | County estimate |
| Bishopville | 52.5 | 3.1 | Soft | County estimate |
| Libertytown | 64.8 | 3.8 | Moderately hard | County estimate |
| Hollywood | 5.7 | 0.3 | Soft | County estimate |
| Jessup | 60.1 | 3.5 | Moderately hard | County estimate |
| Towson | 216.0 | 12.6 | Very hard | County estimate |
| Sunderland | 127.0 | 7.4 | Hard | County estimate |
| Waldorf | 30.6 | 1.8 | Soft | County estimate |
| Queen Anne | 58.5 | 3.4 | Soft | County estimate |
| Cordova | 44.0 | 2.6 | Soft | County estimate |
| Chester | 58.5 | 3.4 | Soft | County estimate |
| Ellicott City | 82.4 | 4.8 | Moderately hard | Utility-reported |
| Swanton | 89.4 | 5.2 | Moderately hard | County estimate |
| Church Hill | 58.5 | 3.4 | Soft | County estimate |
| Port Republic | 127.0 | 7.4 | Hard | County estimate |
| St. Leonard | 127.0 | 7.4 | Hard | County estimate |
| Union Bridge | 64.8 | 3.8 | Moderately hard | 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 Maryland's Water Hardness
Maryland sits in the Appalachian and Mid-Atlantic mixed terrain region.
The Mid-Atlantic and Appalachian states sit on a patchwork of sandstone, shale, and crystalline rock that yields mostly soft to moderately hard water. The big exception is the region's limestone and dolomite valleys - including the carbonate belt running from Pennsylvania down through the Shenandoah Valley - where groundwater dissolves calcium and magnesium readily and comes out distinctly hard. A city's number here depends heavily on whether its supply draws from upland rivers and reservoirs or from carbonate-valley wells.
Maryland Water Hardness FAQ
Does Maryland have hard water?
On the whole, no — Maryland's statewide median sits below the hard threshold, though some cities run harder. The median is 117.0 mg/L (6.8 gpg) — moderately hard on the USGS scale, where anything above 120 mg/L (7 gpg) counts as hard. 4 of Maryland's 118 measured cities fall in the hard or very hard bands (3%), so check your own city rather than the state average.
How hard is tap water in Maryland?
Across the 118 Maryland cities with measured values in our index, the median hardness is 117.0 mg/L (6.8 gpg) — moderately hard on the USGS scale. Individual cities range from 2.2 to 132.0 mg/L, so check your own city rather than assuming the state number.
Which city in Maryland has the hardest water?
Urbana has the hardest measured tap water in our Maryland index at 132.0 mg/L (7.7 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 Maryland?
4 of Maryland's 118 measured cities (3%) 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 Maryland 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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