What Bay County, FL's soil rates for a septic system
Very limited
77.7% of Bay County, FL's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. Practically, that rules out a simple gravity system for most of the county - 77.7% of it sits in USDA's most-constrained bucket. Bay County covers 758.62 square miles and counts 199,718 residents.
This is a county figure, not a parcel figure
Nothing about Bay County, FL'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 Bay County.
System cost, conventional vs. engineered
Given Bay 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, Bay County, FL is the 2,151-most-constrained of 3,058 rated counties for septic soil. Within Florida alone it ranks 46 of 65.
Before you act on this
How this rating is built, and its real limits · Conventional vs. engineered septic systems