The Dense Medium Plasma Water Purification Reactor offers significant improvements over existing water purification technologies used in Advanced Life Support systems such as bioreactors, catalysts, and membrane based systems. Evaluation of water contaminated with bacteria and plasma-treated indicates that, prior to any optimization of the DMP reactor, contamination levels can be reduced by up to 99.9%. Organic contaminant concentrations (benzene, toluene, ethyl benzene, xylene) can be reduced below the detectable range. The DMP reactor is more energy efficient than other Advanced Oxidation Techniques and does not contain expendable materials or produce toxic side products. The atmospheric-pressure plasma is initiated and sustained through a large number of micro-discharges between a rotating pin-array electrode and a stationary electrode. The plasma breaks down organic compounds via the generation of OH? and H? free radicals through interaction at the gas-liquid boundary. The DMP reactor uses non-equilibrium, low temperature, atmospheric-pressure plasmas for the volume-plasma-processing of liquid-phase compounds (water-based solutions). This Partial Discharge (PD) plasma is considered a highly localized electrical discharge produced across an insulating medium, typically between two electrodes. Characteristics of a PD are highly dependent upon electrode geometry and operational parameters and, therefore, require significant research for optimization into a NASA ALS setting.