Research and development work to optimize the BIOSOR (TM)-Manure, a biofiltration process for pig manure treatment, have been realized on the site of a piggery ((I) over cap le d'Orleans, Quebec, Canada) using a 400 m(3) biofiltration system. Despite strong variations in BOD5 (10,000-20,000 mg/L), in SS (10,000-20,000 mg/L), in TKN (20003800 mg/L) and in P-tot (500-900 mg/L), the BIOSOR (O) over cap system was able to maintain an overall pollutant removal performance averaging > 95% for the BOD5 > 97% for the SS, > 84% for the TKN and > 87% for the P-tot. By reducing the raw manure's organic load by more than 95%, the process eliminates over 80% the odour intensity coming from the production installations, the storage, the transportation and the spreading of the manure. The results obtained show that the BIOSOR (TM)-Manure process is an efficient, simple and performing technology bringing a global solution to pig manure problems.