Septic soil in Hillsborough County, FL, by the numbers

Very limited

In Hillsborough County, FL, 89.3% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 89.3% of the county. Hillsborough County, FL is 1,022.539 square miles with a population of 1,581,426.

What Hillsborough County's reading doesn't cover

This is a countywide, area-weighted figure across every soil survey map unit in Hillsborough County, FL - never a reading for one specific parcel. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Hillsborough County will actually do.

What a system would cost here

With 89.3% of Hillsborough County rating "Very limited", a standard gravity system is not a safe assumption here. 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.

Hillsborough County's rank among Florida counties

Nationally, Hillsborough County, FL is the 1,339-most-constrained of 3,058 rated counties for septic soil. Within Florida alone it ranks 24 of 65.

Further reading

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