This is the first report from CERF's Environmental Technical Evaluation Center. The report describes the performance of the Ammonia Recovery Process (ARP), a patented method for recycling ammonia in wastewater. Tests have found that the ARP system is capable of removing 75 to 99 percent of the ammonia in the waste stream in a domestic wastewater treatment plant. Manufactured by ThermoEnergy Environmental Corporation of Little Rock, Arkansas, ARP uses a series of absorption, evaporation, and crystallization steps to convert ammonia in wastewater into a commercial fertilizer, ammonium sulphate. The evaluation results clearly indicate that the ARP process is capable of achieving significant ammonia reduction under a range of environmental conditions.