Denton County, TX's soil, for a septic absorption field

Very limited

82.6% of Denton County, TX's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. Practically, that rules out a simple gravity system for most of the county - 82.6% of it sits in USDA's most-constrained bucket. Denton County covers 878.762 square miles and counts 1,045,120 residents.

This is a county figure, not a parcel figure

This is a countywide, area-weighted figure across every soil survey map unit in Denton County, TX - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Denton County.

System cost, conventional vs. engineered

Given Denton 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.

Where this sits nationally

Nationally, Denton County, TX is the 1,883-most-constrained of 3,058 rated counties for septic soil. Within Texas alone it ranks 140 of 253.

Further reading

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