Red Willow County's SSURGO septic rating
Somewhat limited
Red Willow County, NE's SSURGO dominant class comes back "Somewhat limited", covering 66.1% of the county. Modification usually rescues a conventional system at this rating - added fill or a larger field - rather than forcing a full engineered redesign. The county spans 717.17 square miles, home to 10,409 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Red Willow County, NE 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.
Red Willow County: conventional vs. engineered cost
66.1% of Red Willow County carrying a "Somewhat 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Red Willow County, NE ranks 2,988 most-constrained nationally, and 93 of 93 within Nebraska.
Related guides
How this rating is built, and its real limits · How a percolation test actually works