VIRTUAL TOUR -- City parking lot site -- between Santa Cruz and Menlo Avenues at Crane St. -- BIOFILTER Sand and soil with better drainage were used for the Phase 2 biofilter, and it drains as expected. This photo shows the Phase 1 biofilter with the overflow inlet. The sand and soil of the Phase 1 biofilter may be replaced at some point, but for the time being, the overflow inlets significantly reduce ponding. 1/24/07