Madison County's SSURGO septic rating
Very limited
Madison County, KY's SSURGO dominant class comes back "Very limited", covering 93.1% of the county. Practically, that rules out a simple gravity system for most of the county - 93.1% of it sits in USDA's most-constrained bucket. The county spans 437.94 square miles, home to 99,582 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Madison County, KY at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Madison County: conventional vs. engineered cost
93.1% of Madison County carrying a "Very limited" reading changes the realistic budget here. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.
How Madison County, KY compares
Among the 3,058 rated counties on this site, Madison County, KY ranks 909 most-constrained nationally, and 44 of 119 within Kentucky.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems