California Code, Public Utilities Code - PUC § 21207

Whenever a political subdivision owning and operating an airport constructs or implements a noise mitigation project at the airport, including, but not limited to, the installation of noise monitoring equipment at any time after the project has been included within the aeronautics program in the state transportation improvement program and prior to funding of the project, the department shall, when funding for the project becomes available, reimburse the political subdivision for the eligible costs of the project, without interest, not to exceed the amount of the funds made available to the department or the political subdivision's actual eligible costs, whichever is lower.  Reimbursement under this section shall be made only if the political subdivision completes the project to the standards approved by the department including, but not limited to, bidding and contracting procedures and the project is approved by the commission.  This section does not apply to any project for which state funding is not specifically made available.