Septic companies in Rapid City, SD

What the ground in Rapid City is like

The USDA soil survey rates mapped ground in Rapid City for septic drain-field suitability across roughly 56 square miles. About 63% of the rated ground is classed "Very limited", the survey records severe restrictions for a conventional drain field across most of that ground.

In Rapid City, the leading limit is slow water movement: effluent does not drain through the soil fast enough, so a conventional field can back up or pond when the ground cannot keep pace. The survey flags that limit on about 69% of the rated ground here.

The limiting features the survey records most often here:

• Slow water movement69.2%
• Slope49.6%
• Depth to bedrock37.5%
• Flooding10.1%

This is survey data for mapped areas, not a substitute for a site evaluation on your own lot. Conditions on a single parcel can differ from the map.

USDA NRCS SSURGO, ENG Septic Tank Absorption Fields · 62.6% Very limited · Slow water movement · 99 map units · 55.99 sq mi · read 2026-08-30