Gwinnett County, GA's soil, for a septic absorption field

Somewhat limited

In Gwinnett County, GA, 53.4% of the surveyed land carries a "Somewhat limited" rating for a standard septic drain field. 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. Gwinnett County covers 431.135 square miles and counts 1,003,869 residents.

This is a county figure, not a parcel figure

USDA's survey covers the whole of Gwinnett County, GA at once, not any single address. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Gwinnett County.

System cost, conventional vs. engineered

Given Gwinnett 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, Gwinnett County, GA is the 2,935-most-constrained of 3,058 rated counties for septic soil. Within Georgia alone it ranks 114 of 159.

Further reading

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