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

Very limited

89.3% of Wilson 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. That reading means a conventional system is a poor bet here - 89.3% of Wilson County lands in the strictest "very limited" bucket USDA uses. Wilson County covers 803.735 square miles and counts 55,415 residents.

This is a county figure, not a parcel figure

Nothing about Wilson County, TX'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 Wilson County.

System cost, conventional vs. engineered

Given Wilson 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, Wilson County, TX is the 1,343-most-constrained of 3,058 rated counties for septic soil. Within Texas alone it ranks 98 of 253.

Further reading

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