Septic soil in Rockingham County, NC, by the numbers

Very limited

Soil across 54.2% of Rockingham County, NC rates "Very limited" in USDA's septic-absorption-field interpretation. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 54.2% of Rockingham County's land. Rockingham County covers 565.642 square miles and counts 93,517 residents.

This is a county figure, not a parcel figure

Nothing about Rockingham County, NC's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Rockingham County.

System cost, conventional vs. engineered

Given Rockingham 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.

How Rockingham County, NC compares

Nationally, Rockingham County, NC is the 2,835-most-constrained of 3,058 rated counties for septic soil. Within North Carolina alone it ranks 80 of 97.

Further reading

How this rating is built, and its real limits · Conventional vs. engineered septic systems