Ramal Norte Pipeline is a 27 km long subsurface pressure pipeline that provides drinking water from Huachipa Water Treatment Plant to several districts in Lima, Peru. The pipeline was in temporary operation mode, awaiting completion of the distribution systems, when a 1,600 mm dia. (approximately 63 in. dia.) ductile iron, mortar-lined water main ruptured. SGH investigated the cause of failure and evaluated the likelihood of similar failures at other locations in the pipeline.