The psychrophilic anaerobic treatment is realized at temperatures ranging between 5 to 25 C. This anaerobic treatment is more promising under Canadian conditions than mesophilic and thermophilic anaerobic processes where higher temperatures in the reactor has to be maintained. The results presented are promising however the experiment were done on a laboratory scale as this type of treatment is technically feasible on a larger scale, it is stable and easy to operate. The investment cost of such equipment are not discussed.