This paper discusses the results of a full-scale contactor study conducted to compare the physical characteristics and adsorption capacities of virgin and reactivated granular activated carbon (GAC). Virgin and reactivated carbon contactors were set up in a parallel system, eliminating variables such as bed volume and flow rate. The study included total organic carbon (TOC) breakthrough curves, morphological examination of the carbons as a function of days in service, maximum formation potential total trihalomethane profiles, simulated distribution system disinfection byproduct (DBP) formation profiles, and an equilibrium adsorption isotherm study of benzene as a function of adsorbed TOC. The TOC concentrations of the effluents were then correlated with the morphological data, DBP formation profiles and bench-scale adsorption isotherm data. Although the morphology and sorption properties of the GAC changed over the course of several loading/reactivation cycles, performance was not compromised. In fact, these data suggest that the reactivated carbon can remove significantly more DBP precursors than the virgin carbon, while still offering adequate protection against synthetic organic chemicals.