The payment of the Federal share of costs incurred in the conduct of activities included under a Project Agreement shall be in accordance with Treasury Circular 1075.

(a) Federal payments under the Act shall not exceed 75 percent of the program costs as stated in the agreement; except, the Federal share may be increased to 90 percent when two or more States having a common interest in one or more endangered or threatened species, the conservation of which may be enhanced by cooperation of such States, enter jointly into an agreement with the Secretary.

(b) The State share of program costs may be in the form of cash or in-kind contributions, including real property, subject to standards established by the Secretary as provided in Office of Management and Budget Circular A-102.

(c) Payments under the Endangered Species Act, including such preliminary costs and expenses as may be incurred in connection with projects, shall not be made unless all documents that may be necessary or required in the administration of this Act shall have first been submitted to and approved by the Secretary. Payments shall be made for expenditures reported and certified by the State agencies. Payments shall be made only to the State office or official designated by the State agency and authorized under the laws of the State to receive public funds of the State.

(d) Vouchers and forms provided by the Secretary and certified as therein prescribed, showing amounts expended and the amount of Federal Aid funds claimed to be due on account thereof, shall be submitted to the Secretary by the State agency.