Witness key testing and inspection activities (soil density/compaction, concrete slump, air content, temperature, cylinder, rebar placement) to confirm that contractor QC inspections and testing are being performed correctly, at the required frequency, and acceptance criteria are being met. Perform audits and surveillances of contractor/subcontractor QC programs (inspection procedures, material control, corrective actions, documentation); prepare findings, observations, and non-conformances with corrective actions for the Civil QA Lead.