Lehigh County, PA Shrink-Swell Risk
What Lehigh County, PA's soil means for a foundation
Low
USDA's SSURGO data puts Lehigh County, PA's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 1.75% across 75.7% of the county's surveyed land. That's as favorable a county-level reading as this dataset produces - standard foundation practice, pending one lot's own geotechnical report.
This is a county figure, not a lot figure
USDA's survey covers the whole of Lehigh County, PA at once, not any single address. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).
Report cost vs. repair cost
With Lehigh County, PA rating "Low", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.
Where this sits nationally
Nationally, Lehigh County, PA is the 2,214-most-constrained of 3,085 rated counties for shrink-swell soil. Within Pennsylvania alone it ranks 16 of 67. Lehigh County, PA is 345 square miles with a population of 385,655.
See how another county compares
Orleans Parish, LA carries this site's most-constrained reading. Clermont County, OH and Lewis County, TN are worth a look for comparison.
How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil
More of Pennsylvania
Every county in Pennsylvania is on this site, including Mifflin County, PA and Montgomery County, PA. The full underlying dataset is downloadable directly, one row per county.