How hard is the water in Baltimore city, MD?
7.6 grains per gallon
A softener is worth it here.
The median hardness measured in Baltimore city, MD is 130 mg/L as calcium carbonate, which is 7.6 gpg. That is hard on the USGS scale. It comes from 3 samples at 3 sites between 2000 and 2003, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 6.5 and 15.5 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: low (how it is measured).
What to do next
At 7.6 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Baltimore city straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
Wells 23.5 gpg, rivers and lakes 7.6 gpg
1 groundwater samples from 1 wells put the median at 402 mg/L. 1 surface samples from 1 sites put it at 130 mg/L. In Baltimore city the wells come out 15.9 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 166 lb of salt a year (5 bags of 40 lb, about $30), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $130 a year.
Sizing at 7.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 456 | 24,000 | 55 lb |
| 2 | 912 | 24,000 | 111 lb |
| 4 | 1,824 | 24,000 | 222 lb |
| 6 | 2,736 | 24,000 | 333 lb |
Baltimore city against the rest of Maryland
Among the 24 Maryland counties with data, Baltimore city is number 4 of 24 counting from the hardest. Across the whole country it is harder than 41% of counties.
Softest in Maryland: Charles County at 0.3 gpg. Hardest: Washington County at 18.5 gpg. Closest to Baltimore city: Calvert County (7.5), Carroll County (6.4), Montgomery County (6.4).