Canyon County, ID: the USDA septic-suitability picture

Very limited

Canyon County, ID's SSURGO dominant class comes back "Very limited", covering 65.2% of the county. Practically, that rules out a simple gravity system for most of the county - 65.2% of it sits in USDA's most-constrained bucket. The county spans 587.049 square miles, home to 266,892 people.

What this number does and doesn't tell you

USDA's survey covers the whole of Canyon County, ID at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.

Canyon County: conventional vs. engineered cost

65.2% of Canyon County carrying a "Very limited" reading changes the realistic budget here. 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.

Canyon County's rank among Idaho counties

Among the 3,058 rated counties on this site, Canyon County, ID ranks 2,604 most-constrained nationally, and 38 of 44 within Idaho.

Further reading

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