Septic suitability in Kent County, DE
Very limited
Kent County, DE: USDA's soil survey calls 67.1% of the county "Very limited" for a septic leach field. Practically, that rules out a simple gravity system for most of the county - 67.1% of it sits in USDA's most-constrained bucket. The county spans 586.061 square miles, home to 192,690 people.
What this number does and doesn't tell you
Nothing about Kent County, DE's SSURGO figure applies to a specific address - it's a county-wide average. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Kent County: conventional vs. engineered cost
67.1% of Kent 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, Kent County, DE ranks 2,558 most-constrained nationally, and 2 of 3 within Delaware.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems