Purpose. This Engineer Manual (EM) is intended to provide detailed guidance on all phases of remediation projects involving Multi-phase Extraction (MPE). This includes guidance on (1) the appropriate site characterization and pilot studies for MPE; (2) appropriate considerations in screening MPE for a site; (3) design of subsurface and above-ground components (excluding off gas and water treatment systems); and (4) start-up, operations and maintenance, and site closure.