Lake County's SSURGO septic rating
Very limited
USDA puts Lake County, TN at "Very limited" for septic absorption fields, the dominant reading across 83.4% of the county's soil. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. The county spans 165.785 square miles, home to 6,422 people.
What this number does and doesn't tell you
Lake County's rating is an average across the whole county, not a promise about any one lot inside it. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Lake County: conventional vs. engineered cost
83.4% of Lake 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 Lake County, TN compares
Among the 3,058 rated counties on this site, Lake County, TN ranks 1,834 most-constrained nationally, and 43 of 95 within Tennessee.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems