Allen County's SSURGO septic rating

Very limited

USDA puts Allen County, IN at "Very limited" for septic absorption fields, the dominant reading across 89.6% of the county's soil. Practically, that rules out a simple gravity system for most of the county - 89.6% of it sits in USDA's most-constrained bucket. The county spans 657.146 square miles, home to 399,295 people.

What this number does and doesn't tell you

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

Allen County: conventional vs. engineered cost

89.6% of Allen 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.

Allen County's rank among Indiana counties

Among the 3,058 rated counties on this site, Allen County, IN ranks 1,306 most-constrained nationally, and 61 of 90 within Indiana.

Before you act on this

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