High concentrations of groundwater pollutants such as nitrates (NO₃^-), Escherichia coli (E. coli), and total coliform (TC) have been continuously reported in numerous agricultural, pre-urban, and urban settings around the world. These are primarily from anthropogenic sources such as excessive nitrogen-based fertilizers, increased food waste in landfills, and unkept sanitation facilities. Electrochemical methods to lower these concentrations to drinking water standards (<50 mg NO₃^-/L and 0 CFU/100mL TC) have become the more preferred treatment processes since they are relatively cleaner and cheaper, i.e., they only utilize electrons for species conversion, and do not employ and/or replenish biotic and chemical components during the treatment process. NO₃^- can be electrochemically reduced to an inert (N₂) and/or a more usable form (NH₃), while naturally-contained chlorine (Cl^-) ions in groundwater can be oxidized to chlorine (Cl₂) which can then be hydrolysed to common water disinfectants—hypochlorous acid (HOCl) and hypochlorite (OCl^-). However, these methods are limited by low reduction rate, poor selectivity, and energy intensiveness—concerns that can be addressed by incorporating electric pulsing and nanomaterial-enhanced electrodes in the treatment chamber as demonstrated in this study. A two-compartment flow-through device supplied with dual polarity pulsing (V_cathode=-1.3V, V_anode=0.1, 90% duty cycle, and 0.2Hz) was used to simultaneously treat NO₃^- and E. coli in simulated groundwater. The working electrode, Ru-PDA/Cu_xO NW on Cu mesh, possesses Ru’s high activity for reducing NO₃^- to NH₃, and PDA/Cu_xO NW’s reliable bactericidal properties. NO₃^- was removed with >70% efficiency from an initial concentration of 178 mg NO₃^-/L with NH₃ as the main by-product, while at least 1-log reduction in E. coli (ATCC 25922) was achieved from an initial concentration of ~10⁵ CFU/mL within a mean residence time of <60 seconds.