Sublette County, WY's soil, for a septic absorption field
Very limited
In Sublette County, WY, 82.4% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Practically, that rules out a simple gravity system for most of the county - 82.4% of it sits in USDA's most-constrained bucket. Sublette County covers 4,886.482 square miles and counts 8,965 residents.
This is a county figure, not a parcel figure
Two lots a mile apart in Sublette County can carry different soil, even though they share one countywide rating. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Sublette County.
System cost, conventional vs. engineered
Given Sublette 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.
Sublette County's rank among Wyoming counties
Nationally, Sublette County, WY is the 1,902-most-constrained of 3,058 rated counties for septic soil. Within Wyoming alone it ranks 3 of 22.
Before you act on this
How this rating is built, and its real limits · Conventional vs. engineered septic systems