Hamilton County, IL: the USDA septic-suitability picture

Very limited

Hamilton County, IL's SSURGO dominant class comes back "Very limited", covering 98.6% of the county. That reading means a conventional system is a poor bet here - 98.6% of Hamilton County lands in the strictest "very limited" bucket USDA uses. The county spans 434.653 square miles, home to 7,818 people.

What this number does and doesn't tell you

USDA's survey covers the whole of Hamilton County, IL at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.

Hamilton County: conventional vs. engineered cost

98.6% of Hamilton 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.

Where this sits nationally

Among the 3,058 rated counties on this site, Hamilton County, IL ranks 162 most-constrained nationally, and 11 of 101 within Illinois.

Before you act on this

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