What Adams County, WA's soil rates for a septic system
Very limited
In Adams County, WA, 58.6% of the surveyed land carries a "Very limited" rating for a standard septic drain field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 58.6% of Adams County's land. Adams County, WA is 1,924.989 square miles with a population of 21,039.
What Adams County's reading doesn't cover
Adams County's rating is an average across the whole county, not a promise about any one lot inside it. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Adams County will actually do.
What a system would cost here
With 58.6% of Adams County rating "Very limited", a standard gravity system is not a safe assumption here. 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.
How Adams County, WA compares
Nationally, Adams County, WA is the 2,751-most-constrained of 3,058 rated counties for septic soil. Within Washington alone it ranks 37 of 39.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems