Alberta oil sands process water (OSPW) contains several contaminants of environmental concern, particularly toxic naphthenic acids (NAs). Currently there is no suitable treatment for OSPW therefore it is collected and stored in tailings ponds. OSPW toxicity can be mitigated by aerobic microbial degradation of the NAs by indigenous microorganisms in-situ, however this is a long and slow process. Ex-situ bioremediation of OSPW presents a much more efficient method to detoxify OSPW. The microorganisms chosen, and their method of growth have consequences on the success of a bioremediation effort. Here we evaluate biofilm-mediated bioremediation of model NAs, specifically comparing multi species to single species biofilms. The Calgary Biofilm Device (CBD) was used to grow biofilms from an OSPW inoculum. Gas chromatography reveals that multi species biofilms are capable of degrading a broader spectrum of NAs than are single species biofilms, which may be indicative of a communal/synergistic metabolic effort.