Mason County, TX's soil, for a septic absorption field
Very limited
Soil across 93.7% of Mason County, TX rates "Very limited" in USDA's septic-absorption-field interpretation. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 93.7% of the county. Mason County covers 928.836 square miles and counts 3,987 residents.
This is a county figure, not a parcel figure
This is a countywide, area-weighted figure across every soil survey map unit in Mason 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 Mason County.
System cost, conventional vs. engineered
Given Mason 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.
Mason County's rank among Texas counties
Nationally, Mason County, TX is the 843-most-constrained of 3,058 rated counties for septic soil. Within Texas alone it ranks 56 of 253.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems