Anodic photocorrosion and cathodic photowashing of n-GaAs(100) in a nonaqueous photoelectrochemical cell have been studied using photoluminescence decays and the voltage dependence of both photoluminescence intensity and photocurrent. Photocorrosion of the cell, which is attributed to trace water contamination, results in an increased surface recombination velocity and an overall loss in photoluminescence intensity, but does not affect the photocurrent. The stability of the photocurrent upon corrosion of the cell implies that the photoinduced surface states resulting from the corrosion are intrinsically different from those observed in all other systems studied previously in this laboratory. The techniques listed above were also used to monitor changes in the n-GaAs/methanol interface with incremental water additions to the cell to study the effects of water contamination.