The Comprehensive Safety Review includes temperature and noise tests, ultrasonic imaging, cement bond tests, magnetic flux leakage tests, multi-arm caliper tests, and hydro-pressure tests of both the wells' casings and of the steel tubing within the wells. A video of the comprehensive inspection process is available here. Root Cause Analysis SoCalGas continues to work in support of the CPUC Safety and Enforcement Division's and DOGGR's ongoing investigation of the root cause of the leak at Aliso Canyon. The investigation is now expected to be completed during the first half of 2017, but the timing is under the control of the CPUC Safety Enforcement Division and DOGGR. About Southern California Gas Co. Southern California Gas Co. (SoCalGas) has been delivering clean, safe and reliable natural gas to its customers for more than 145 years.