Increasing in situ extraction of oil sands bitumen has made the recovery of contaminated process water a more important, and more pressing, challenge. We have machined thin membranes that have a high zeolite content, offer high thermal and chemical stability, and are essentially free of intercrystalline voids. The membranes were produced from natural zeolites from a high-density deposit in British Columbia. These membranes were found to be able to greatly reduce ionic content and almost completely remove all toluene from synthetic process water at 85 degrees C and 1 atm feed-side pressure under pervaporative operation. Membrane flux was insensitive to toluene over the concentration range tested (10-220 mg/L) but decreased with increasing ionic content. This initial study shows promise as a once-through membrane process that can withstand high temperature and organic contamination. (C) 2011 Elsevier B.V. All rights reserved.