Spec 2325 – Castlewood Zone 2 Tank Replacement Project

The archived Spec 2325 report delivers a detailed geotechnical and geological assessment for the Castlewood Zone 2 tank replacement in Pleasanton, CA. It reviews historic subsurface data, conducts limited new soil sampling, provides laboratory test results, and issues design recommendations for foundations, retaining walls, earthwork, drainage, and seismic compliance within an Alquist‑Priolo Earthquake Fault Zone. The report is intended for use by the client (California Water Service Company via Pakpour Consulting Group) and remains valid for two years from issuance. • Updated limited geological site assessment with new surficial soil sampling and lab testing. • Foundation recommendations (pier‑supported mat or mat on bedrock) and retaining‑wall options, with detailed seismic design parameters (Site Class C, SDC F, PGA 0.902 g). • Guidance on construction‑phase observation, compaction standards, corrosion mitigation, and regulatory compliance (2013 California Building Code, ASCE 7‑10, AWWA standards). • All prior investigations (2007‑2012) are incorporated; the report is archived and not a current solicitation.