Franklin County, NC's soil, for a septic absorption field

Somewhat limited

Soil across 59.6% of Franklin County, NC rates "Somewhat limited" in USDA's septic-absorption-field interpretation. That's a middle reading: not the outright failure "very limited" soil produces, but not a clean pass either. Design changes often bridge the gap. Franklin County covers 491.874 square miles and counts 79,771 residents.

This is a county figure, not a parcel figure

This is a countywide, area-weighted figure across every soil survey map unit in Franklin County, NC - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Franklin County.

System cost, conventional vs. engineered

Given Franklin County's rating, plan for the engineered-system range rather than the conventional one. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

Where this sits nationally

Nationally, Franklin County, NC is the 2,969-most-constrained of 3,058 rated counties for septic soil. Within North Carolina alone it ranks 91 of 97.

Related guides

How this rating is built, and its real limits · How a percolation test actually works