Septic soil in Cumberland County, IL, by the numbers

Very limited

Soil across 96.2% of Cumberland County, IL rates "Very limited" in USDA's septic-absorption-field interpretation. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 96.2% of Cumberland County's land. Cumberland County covers 345.946 square miles and counts 10,305 residents.

This is a county figure, not a parcel figure

Nothing about Cumberland County, IL's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Cumberland County.

System cost, conventional vs. engineered

Given Cumberland County's rating, plan for the engineered-system range rather than the conventional one. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

How Cumberland County, IL compares

Nationally, Cumberland County, IL is the 504-most-constrained of 3,058 rated counties for septic soil. Within Illinois alone it ranks 23 of 101.

Before you act on this

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