Section 505.13 - Federal Government's share of project cost(a) Based on engineering studies, studies of economic feasibility, and information on the expected use of equipment or facilities, the Secretary shall estimate the project's eligible costs.(b) A FFGA for the project shall not exceed 80 percent of the eligible project cost. A refund or reduction of the remainder may only be made if a refund of a proportional amount of the grant of the Federal Government is made at the same time.