Spokane County's SSURGO septic rating

Very limited

Spokane County, WA's SSURGO dominant class comes back "Very limited", covering 89.8% of the county. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 89.8% of Spokane County's land. For scale: 1,764.224 square miles and 555,947 people call Spokane County home.

Before you rely on this for one lot

USDA's survey covers the whole of Spokane County, WA at once, not any single address. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Spokane County, WA

Spokane County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.

Spokane County's rank among Washington counties

Among the 3,058 rated counties on this site, Spokane County, WA ranks 1,285 most-constrained nationally, and 25 of 39 within Washington.

Before you act on this

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