Penhall Company was contracted to perform the wrecking of an existing odor control facility at Hyperion Waste Water Treatment Plant. The work scheduled to occur in three phases includes interior wrecking of obsolete pumps, blowers, equipment, slab, and selective portions of structure. On the exterior of the structure Penhall Company wrecked approx. 5,000 SF of scrubbers, towers, piping, supports, cat walks, and other miscellaneous equipment. Penhall Company has demolished approx. 5,000 SF of slab including pads and foundations in excess of 6’ thick. General Contractor and City of Los Angeles have had issues locating and identifying utilities within our work areas. 480v “unidentified” lines were uncovered during demolition. No incident/injury due to Penhall Company superintendent identifying and notifying GC.