(a) In order to implement and administer a revolving loan program established under Title VI of the Federal Water Pollution Control Act (33 U.S.C. § 1381 et seq.), the board may direct the comptroller to transfer amounts from the financial assistance account to the state water pollution control revolving fund created by § 15.601 to provide financial assistance pursuant to this subchapter.
(b) In order to implement and administer a revolving loan program established by any other federal legislation, including, without limitation, Title XIV of the federal Public Health Service Act, or any federal agency program under which an additional state revolving fund, as defined in § 15.602, has been established, the board may direct the comptroller to transfer amounts from the financial assistance account to such additional state revolving fund to provide financial assistance pursuant to this subchapter.

(c) The board shall use the state water pollution control revolving fund in accordance with § 15.604(a)(4) and Section 603(d)(4), Federal Water Pollution Control Act (33 U.S.C. § 1383), as a source of revenue to be deposited in accordance with this subchapter for the payment of principal and interest on water financial assistance bonds issued by the board, the proceeds of which are deposited into the state water pollution control revolving fund, and to make payments under a bond enhancement agreement with respect to principal or interest on the water financial assistance bonds.
(d) In the event amounts are transferred to any additional state revolving fund, as defined in § 15.602, pursuant to Subsection (b), the board shall, to the extent permitted by the federal legislation or federal agency program under which such additional state revolving fund was established, use the additional state revolving fund as a source of revenue to be deposited in accordance with this subchapter for the payment of principal and interest on water financial assistance bonds issued by the board, the proceeds of which are deposited into the additional state revolving fund, and to make payments under a bond enhancement agreement with respect to principal or interest on the water financial assistance bonds.