Septic suitability in Phillips County, KS
Very limited
USDA puts Phillips County, KS at "Very limited" for septic absorption fields, the dominant reading across 50.2% of the county's soil. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. The county spans 885.871 square miles, home to 4,733 people.
What this number does and doesn't tell you
Phillips County's rating is an average across the whole county, not a promise about any one lot inside it. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Phillips County: conventional vs. engineered cost
50.2% of Phillips 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Phillips County, KS ranks 2,884 most-constrained nationally, and 92 of 105 within Kansas.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems