Septic suitability in Santa Clara County, CA

Very limited

Santa Clara County, CA: USDA's soil survey calls 80.6% of the county "Very limited" for a septic leach field. 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 1,291.084 square miles, home to 1,926,325 people.

What this number does and doesn't tell you

Santa Clara 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.

Santa Clara County: conventional vs. engineered cost

80.6% of Santa Clara 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.

Santa Clara County's rank among California counties

Among the 3,058 rated counties on this site, Santa Clara County, CA ranks 2,008 most-constrained nationally, and 51 of 57 within California.

Before you act on this

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