This study was performed to provide specific information and knowledge on an improved methodology for anaerobic treatability/toxicity screening test procedure. This methodology makes use of 125ml glass syringes as the reactor vessel. Healthy anaerobic bacteria produce methane, carbon dioxide and sometimes hydrogen sulfide. Measuring gas production accurately is critical in evaluating the performance of anaerobic bacteria. The goal of this study was to develop operating parameters for the new methodology so that the test procedure may be used properly, saving time and money. The new test procedure was reviewed in evaluating ammonia-nitrogen and nickel toxicity.