Adams County, CO's soil, for a septic absorption field
Somewhat limited
Soil across 47.8% of Adams County, CO rates "Somewhat limited" in USDA's septic-absorption-field interpretation. That's a middle reading: not the outright failure "very limited" soil produces, but not a clean pass either. Design changes often bridge the gap. Adams County covers 1,166.8 square miles and counts 542,973 residents.
This is a county figure, not a parcel figure
This is a countywide, area-weighted figure across every soil survey map unit in Adams County, CO - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Adams County.
System cost, conventional vs. engineered
Given Adams County's rating, plan for the engineered-system range rather than the conventional one. 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.
Adams County's rank among Colorado counties
Nationally, Adams County, CO is the 2,955-most-constrained of 3,058 rated counties for septic soil. Within Colorado alone it ranks 60 of 63.
Related guides
How this rating is built, and its real limits · How a percolation test actually works