Cal. Pub. Resources Code § 3403
There shall annually be imposed upon the person operating each gas well in this state, or owning royalty or other interests with respect to the production from the well, a charge, which shall be payable to the Treasurer, based upon the amount of gas produced in the preceding calendar year, other than gas which is used for recycling or otherwise in oil-producing operations, and which shall be computed at a uniform rate per ten thousand cubic feet. The charge shall be apportioned among all of those persons in fractional amounts proportionate to their respective fractional interests with respect to the production of the well, but the whole of the charge shall be payable by the operator, who shall withhold the respective proportionate shares of the charge from the amounts otherwise payable or deliverable to the owners of royalty or other interests. In the case of a penalty for a late payment as provided in Section 3420, no apportionment shall be made.
Ca. Pub. Res. Code § 3403