Porter Ranch already experienced the largest recorded natural gas leak in U.S. history over the winter, when a leak at the Aliso Canyon Storage Facility spewed more than 97,000 metric tons of methane into the atmosphere. Thousands of families were evacuated during the nearly four-month long leak, which was sealed in February. Over the weekend, the neighborhood was hit with another natural gas leak. Residents had been complaining that the smell of natural gas, recognizable by a potent odorant, was again wafting through their Los Angeles neighborhood.
— source thinkprogress.org | 2016