Septic suitability in Richmond County, NY
Very limited
Richmond County, NY: USDA's soil survey calls 76% of the county "Very limited" for a septic leach field. That reading means a conventional system is a poor bet here - 76% of Richmond County lands in the strictest "very limited" bucket USDA uses. The county spans 57.523 square miles, home to 498,212 people.
What this number does and doesn't tell you
Richmond 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.
Richmond County: conventional vs. engineered cost
76% of Richmond 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.
Richmond County's rank among New York counties
Among the 3,058 rated counties on this site, Richmond County, NY ranks 2,233 most-constrained nationally, and 50 of 61 within New York.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems