This strategy plan describes a coupled analytical/experimental approach to develop a multi-functional scarifier end effector coupled with a pneumatic conveyance system to retrieve wastes from underground storage tanks. The scarifier uses ultra-high-pressure water jets to rubblize and entrain waste forms such as salt cake, sludge, and viscous liquid that can be transported pneumatically. The three waste types (hard, brittle, salt cake, viscous liquid, and deformable sludge) present increasingly complex challenges for scarification and pneumatic conveyance. Salt cake is anticipated to be the easiest to retrieve because (1) a theoretical model of hydraulic rock fracture can be applied to estimate jet performance to fracture salt cake, and (2) gas-solids transport correlations can be used to predict pneumatic transport. Deformable sludge is anticipated to be the most difficult to retrieve: no theories, correlations, or data exist to predict this performance. However order-of-magnitude gas-solid correlations indicate particulate wastes of prototypic density can be transported to a height of 20 m within allowable pressure limits provided that the volume fraction of the gaseous phase is kept above 95%. Viscous liquid is anticipated to be of intermediate complexity to retrieve. Phenomena that are expected to affect system performance are ranked. Experiments and analyses necessary to evaluate the effects of these phenomena are proposed. Subsequent strategies for experiment test plans, system deployment, and operation and control will need to be developed.