San Francisco County, CA: no USDA soil-survey match

Unrated

Unlike most of the 3,144 counties on this site, San Francisco County, CA has nothing to show: The dominant soil here (often already-developed urban land) carries no septic-suitability interpretation from USDA - too rare a gap to guess at. A local percolation test is the only way to know.

Before you rely on this for one lot

San Francisco County's rating is an average across the whole county, not a promise about any one lot inside it. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in San Francisco County, CA

Without a countywide reading for San Francisco County, both cost ranges below are worth knowing before a test, not just one. Conventional systems typically run $3,000-$8,000; where the soil doesn't allow one, engineered alternatives run $10,000-$40,000. A perc test decides which range applies.

Before you act on this

How this rating is built, and its real limits · What to check before buying rural land on septic