In furtherance of the purposes of §§ 51.5-63, 51.5-66, and 51.5-72 through 51.5-76, the Department shall have authority to use any receipts or earnings that accrue from the operation of rehabilitative manufacturing and service industries as provided in such sections, but a detailed statement of receipts or earnings and expenditures shall be carefully kept.
Va. Code § 51.5-75