Kennebec County's SSURGO septic rating
Very limited
USDA puts Kennebec County, ME at "Very limited" for septic absorption fields, the dominant reading across 82.7% 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 867.507 square miles, home to 128,461 people.
What this number does and doesn't tell you
Nothing about Kennebec County, ME's SSURGO figure applies to a specific address - it's a county-wide average. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Kennebec County: conventional vs. engineered cost
82.7% of Kennebec 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Kennebec County, ME ranks 1,878 most-constrained nationally, and 10 of 16 within Maine.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems