How hard is the water in Lehigh County, PA?
7.8 grains per gallon
A softener is worth it here.
The median hardness measured in Lehigh County, PA is 134 mg/L as calcium carbonate, which is 7.8 gpg. That is hard on the USGS scale. It comes from 458 samples at 23 sites between 1998 and 2026, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 4.5 and 13 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: high (how it is measured).
What to do next
At 7.8 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 Lehigh County 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.
From 1.6 to 15.8 gpg
The softest single sample on record in Lehigh County was 28 mg/L and the hardest 271 mg/L, a 10-fold gap. The top quarter of sites read above 13 gpg and the bottom quarter below 4.5 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 7.8 gpg, rivers and lakes 7.8 gpg
5 groundwater samples from 3 wells put the median at 134 mg/L. 453 surface samples from 20 sites put it at 133.5 mg/L. In Lehigh County the rivers and lakes come out 0.0 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 171 lb of salt a year (5 bags of 40 lb, about $31), 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 $131 a year.
Sizing at 7.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 468 | 24,000 | 57 lb |
| 2 | 936 | 24,000 | 114 lb |
| 4 | 1,872 | 24,000 | 228 lb |
| 6 | 2,808 | 24,000 | 342 lb |
Lehigh County against the rest of Pennsylvania
Among the 67 Pennsylvania counties with data, Lehigh County is number 35 of 67 counting from the hardest. Across the whole country it is harder than 42% of counties.
Softest in Pennsylvania: Cameron County at 1.4 gpg. Hardest: Clarion County at 68.2 gpg. Closest to Lehigh County: Union County (7.8), Philadelphia County (7.6), Bradford County (8.2).