This demonstration project in a small residential community in Kentucky was initiated to show the feasibility of treating sewage with a physical-chemical type of wastewater treatment plant with a biological process for nitrification. The 50,000 gallon per day system had unit processes consisting of screening, flow equalization, chemical clarification using lime, biological nitrification, filtration, and activated carbon adsorbtion. A significant feature of the demonstration was the reliability with which a high quality effluent could be produced in spite of the numerous equipment and operational problems encountered. Plant removal efficiency, as measured by the removal of BOD5 and suspended solids was 93% and 97%, respectively. Phosphorus levels were reduced by more than 80% during the chemical clarification step. Total nitrogen concentration was reduced by up to one-third during the treatment. Effluent BOD5 and suspended solids levels were significantly lower for this process than the average values obtained from seven various types of biological treatment plants.