A county may expend the net proceeds of the sale of an issue of notes only to: make grants and loans in accordance with § 9–1605.2(h)(2)(i) of the Environment Article; make grants and loans to cover engineering costs and non–best–available–technology components, including drainfields, needed for the repair of existing on–site sewage disposal systems or the installation of new on–site sewage disposal systems that use the best available technology for nitrogen removal; or refund one or more issues of notes.