THREE years after it launched its landmark river cleanup and flood mitigation initiative — which has led to the removal of over 3 million metric tons of silt and solid waste from the Pasig, Tullahan and San Juan Rivers — San Miguel Corp. (SMC) set its sights on a more ambitious goal: cleaning up and rehabilitating three major river systems as well as other tributaries and waterways throughout Metro Manila, Pampanga, Cavite and Bulacan.