Septic suitability in Warren County, IA
Very limited
USDA puts Warren County, IA at "Very limited" for septic absorption fields, the dominant reading across 96.8% of the county's soil. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. The county spans 569.658 square miles, home to 56,343 people.
What this number does and doesn't tell you
Two lots a mile apart in Warren County can carry different soil, even though they share one countywide rating. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Warren County: conventional vs. engineered cost
96.8% of Warren 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.
Warren County's rank among Iowa counties
Among the 3,058 rated counties on this site, Warren County, IA ranks 397 most-constrained nationally, and 30 of 99 within Iowa.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems