8. Hydraulic Displacement Of Dense Nonaqueous Phase Liquids

Hydraulic displacement is a mass removal technology that involves recovering dense nonaqueous phase liquids (DNAPLs) from either vertical wells or horizontal drains. This chapter focuses primarily on the application of hydraulic displacement at sites impacted by chlorinated solvent DNAPLs, although some discussion of other types of DNAPLs also is included. The chapter begins with screening calculations including examples, followed by a discussion of the state of the practice including numerical simulation examples, followed by a case history and concludes with a summary. This chapter also includes definitions of several multiphase flow terms pertinent to DNAPL behavior and hydraulic displacement that may not be familiar to some practitioners in the field of contaminant hydrogeology.