Septic suitability in Casey County, KY
Very limited
Casey County, KY: USDA's soil survey calls 78.5% of the county "Very limited" for a septic leach field. Practically, that rules out a simple gravity system for most of the county - 78.5% of it sits in USDA's most-constrained bucket. The county spans 444.258 square miles, home to 15,948 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Casey 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.
Casey County: conventional vs. engineered cost
78.5% of Casey 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 Casey County, KY compares
Among the 3,058 rated counties on this site, Casey County, KY ranks 2,116 most-constrained nationally, and 93 of 119 within Kentucky.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems