CA SB463

Removes the exemption for well stimulation treatments used in routine maintenance of natural gas storage wells, making these treatments subject to the same permitting and disclosure requirements as other well stimulation treatments.

Requires gas storage well operators to provide the Division of Oil, Gas, and Geothermal Resources with a complete annual chemical inventory of all materials that may be emitted during a reportable leak, including formation fluids, wellbore-produced fluids, and well maintenance materials.

Mandates operators submit the composition of well kill fluids within 5 days of their use in a leaking gas storage well and requires the division to post reportable leak information on its website.

Authorizes the division to require chemical suppliers to furnish information about chemicals to the division if operators cannot obtain it from suppliers, including when suppliers claim trade secret protections.

Requires the division to review and revise natural gas storage well regulations by July 1, 2021, addressing root causes identified in the independent analysis of the 2015 Aliso Canyon gas storage facility leak, including cathodic protection measures and well control plan requirements.