A county may: borrow money for any public purpose; and issue and sell general obligation bonds to evidence the borrowing. By local law, a county may provide for the issuance of revenue bonds payable as to principal and interest solely from the revenues of one or more revenue–producing projects of the county. Notwithstanding any other provision of this subtitle, a county may issue bonds: for sanitary facilities as provided in the Environment Article; and as authorized by local law in effect on the date the county adopts code home rule.