Ottawa County, OK's soil, for a septic absorption field

Very limited

Soil across 85.9% of Ottawa County, OK rates "Very limited" in USDA's septic-absorption-field interpretation. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. Ottawa County, OK is 470.817 square miles with a population of 30,404.

What Ottawa County's reading doesn't cover

Two lots a mile apart in Ottawa County can carry different soil, even though they share one countywide rating. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Ottawa County will actually do.

What a system would cost here

With 85.9% of Ottawa 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.

How Ottawa County, OK compares

Nationally, Ottawa County, OK is the 1,628-most-constrained of 3,058 rated counties for septic soil. Within Oklahoma alone it ranks 32 of 77.

Before you act on this

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