Mellette County, SD: the USDA septic-suitability picture

Very limited

Mellette County, SD's SSURGO dominant class comes back "Very limited", covering 88.5% of the county. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 88.5% of Mellette County's land. For scale: 1,307.311 square miles and 1,834 people call Mellette County home.

Before you rely on this for one lot

Mellette County's rating is an average across the whole county, not a promise about any one lot inside it. 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 Mellette County, SD

Mellette 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, Mellette County, SD ranks 1,426 most-constrained nationally, and 34 of 66 within South Dakota.

Further reading

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