; (III) a percentage of the enhanced revenue to the pay-for-performance beneficiary or the Secretary of Agriculture derived from a project outcome; or (IV) a percentage of the cost of the pay-for-performance project. (C) Forest Service financial assistance Subject to the availability of appropriations, the Secretary of Agriculture may only contribute funding for a pay-for-performance project if— (i) the Secretary of Agriculture demonstrates that— (I) the pay-for-performance project will provide a cost savings to the United States; or (II) the funding would accelerate the pace of implementation of an activity previously planned to be completed by the Secretary of Agriculture; and (ii) the contribution of the Secretary of Agriculture has a value that is not more than 50 percent of the total cost of the pay-for-performance project. (D) Special account Any funds received by the Secretary of Agriculture under subsection (c)(1)— (i) shall be retained in a separate fund in the Treasury to be used solely for pay-for-performance projects; and (ii) shall remain available until expended and without further appropriation. (4) Maintenance and decommissioning of pay-for-performance project improvements A pay-for-performance agreement shall— (A) include a plan for maintaining any capital improvement constructed as part of a pay-for-performance project after the date on which the pay-for-performance project is completed; and (B) specify the party that will be responsible for decommissioning the improvements associated with the pay-for-performance project— (i) at the end of the useful life of the improvements; (ii) if the improvements no longer serve the purpose for which the improvements were developed