This document presents the scope of work for additional data collection activities and interpretive reports to be performed in the off-post operable unit (OU) for preparation of: (1) Addendum to the final remedial investigation report; (2)' Revision of the draft final endangerment assessment/feasibility study. The plan is divided into the following sections: (1) Requirements for the RI addendum - technical approach and data collection program for the RI addendum - technical approach and data collection program for ground water, soil, sediment, biota, air; (2) Revision of the endagerment assessment - items that need to be reevaluated; (3) Revision of the feasibility study - evaluation of different media and ARAR's development of remedial alternatives; (4) Schedule and description of deliverables. Appendix a contains a detailed approach for the 96th avenue risk assessment.-BKA.