The purpose of the memorandum is to amend OSWER Directive 9355.7-02 (May 23, 1991) (PB91-921369). Structure and Components of Five-Year Reviews, by providing supplemental guidance on five-year reviews. The supplemental guidance provides necessary clarifications as well as new direction to streamline the five-year review process and ensure the effective and efficient use of program resources. Specifically, this supplemental guidance: changes the trigger date for policy reviews to construction completion; provides a prioritization plan for conducting five-year reviews when Regions cannot conduct all required reviews; clarifies responsibility for conduct of five-year reviews at Federal facilities; restates that the five-year review covers all operable units (OUs) at a site; and, introduces a streamlined Type Ia review at sites where construction is ongoing, and provides model language.