Pennington County, SD Septic Rating
Septic suitability in Pennington County, SD
Very limited
USDA puts Pennington County, SD at "Very limited" for septic absorption fields, the dominant reading across 83.6% of the county's soil. Practically, that rules out a simple gravity system for most of the county - the reading above is already USDA's most-constrained bucket. The county spans 2,777 square miles, home to 115,979 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Pennington County, SD - never a reading for one specific parcel. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Pennington County: conventional vs. engineered cost
83.6% of Pennington 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 Pennington County, SD compares
Among the 3,058 rated counties on this site, Pennington County, SD ranks 1,812 most-constrained nationally, and 44 of 66 within South Dakota.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems