Monroe County, NY: the USDA septic-suitability picture
Very limited
Monroe County, NY's SSURGO dominant class comes back "Very limited", covering 79.4% of the county. 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 656.967 square miles, home to 752,202 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Monroe County, NY 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.
Monroe County: conventional vs. engineered cost
79.4% of Monroe 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, Monroe County, NY ranks 2,067 most-constrained nationally, and 48 of 61 within New York.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems