What Mercer County, NJ's soil rates for a septic system

Very limited

81.7% of Mercer County, NJ'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 81.7% of Mercer County's land. Mercer County, NJ is 224.482 square miles with a population of 392,138.

What Mercer County's reading doesn't cover

Nothing about Mercer County, NJ's SSURGO figure applies to a specific address - it's a county-wide average. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Mercer County will actually do.

What a system would cost here

With 81.7% of Mercer County rating "Very limited", a standard gravity system is not a safe assumption here. 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.

Mercer County's rank among New Jersey counties

Nationally, Mercer County, NJ is the 1,949-most-constrained of 3,058 rated counties for septic soil. Within New Jersey alone it ranks 13 of 21.

Before you act on this

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