Septic soil in Westchester County, NY, by the numbers

Very limited

58.7% of Westchester County, NY's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 58.7% of Westchester County's land. Westchester County covers 430.817 square miles and counts 1,006,447 residents.

This is a county figure, not a parcel figure

Nothing about Westchester County, NY's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Westchester County.

System cost, conventional vs. engineered

Given Westchester 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.

Westchester County's rank among New York counties

Nationally, Westchester County, NY is the 2,744-most-constrained of 3,058 rated counties for septic soil. Within New York alone it ranks 61 of 61.

Before you act on this

How this rating is built, and its real limits · Conventional vs. engineered septic systems