Custer County's SSURGO septic rating

Very limited

USDA puts Custer County, SD at "Very limited" for septic absorption fields, the dominant reading across 83.6% of the county's soil. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 83.6% of Custer County's land. For scale: 1,556.943 square miles and 9,330 people call Custer County home.

Before you rely on this for one lot

Two lots a mile apart in Custer County can carry different soil, even though they share one countywide rating. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Custer County, SD

Custer County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. 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, Custer County, SD ranks 1,816 most-constrained nationally, and 45 of 66 within South Dakota.

Before you act on this

How this rating is built, and its real limits · Conventional vs. engineered septic systems