O'Brien County's SSURGO septic rating

Very limited

USDA puts O'Brien County, IA at "Very limited" for septic absorption fields, the dominant reading across 98.8% of the county's soil. That reading means a conventional system is a poor bet here - 98.8% of O'Brien County lands in the strictest "very limited" bucket USDA uses. The county spans 573.035 square miles, home to 14,260 people.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in O'Brien County, IA - 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.

O'Brien County: conventional vs. engineered cost

98.8% of O'Brien 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.

O'Brien County's rank among Iowa counties

Among the 3,058 rated counties on this site, O'Brien County, IA ranks 121 most-constrained nationally, and 10 of 99 within Iowa.

Related guides

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