"During the leak and for months afterwards, thousands of indoor and outdoor air, dust, soil, and mud samples were tested during and after the leak, by multiple public health agencies, including the Los Angeles County Department of Health, the South Coast Air Quality Management District, the Air Resources Board, and the Office of Environmental Health Hazard Assessment, and the data demonstrates that Porter Ranch is safe," the statement said.

Source: Los Angeles Times January 13, 2018 21:11 UTC