Rock County's SSURGO septic rating

Very limited

Rock County, WI's SSURGO dominant class comes back "Very limited", covering 87.5% of the county. That reading means a conventional system is a poor bet here - 87.5% of Rock County lands in the strictest "very limited" bucket USDA uses. The county spans 718.168 square miles, home to 165,461 people.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Rock County, WI - 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.

Rock County: conventional vs. engineered cost

87.5% of Rock 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 Rock County, WI compares

Among the 3,058 rated counties on this site, Rock County, WI ranks 1,505 most-constrained nationally, and 50 of 72 within Wisconsin.

Further reading

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