Mill Valley trustees narrow middle-school options after steep soil-disposal costs; approve further geotechnical work

Mill Valley School District trustees on Aug. 14 reviewed updated environmental and budget analyses for the Mill Valley Middle School modernization and approved agreements for further geotechnical, hazardous-material and surveying services to inform a December decision on a preferred alternative.

Superintendent Dr. Kaufman told the board the district’s environmental review has revealed geotechnical conditions that greatly increase costs if full deep soil mixing (DSM) and off‑site spoil disposal are required, citing analyses that raised earlier hard‑cost estimates by tens of millions of dollars. Staff said the soil work and disposal volume—discussed in the meeting as roughly 56,000 cubic yards of spoils in the most intensive scenarios—drove the board to narrow options to two alternatives that will be evaluated in the draft EIR: (1) a value‑engineered renovation of the existing Mill Valley Middle School with a $95 million hard‑cost budget that holds potential soil‑mitigation funds outside that core budget, and (2) building a new campus at 70 Lomita (the Terramarine/Aetna site).

Kaufman said the $95 million renovation approach was intended to avoid adding long‑term…