Providing for individual sewage treatment (septic) system funding; requiring the public facilities authority to biennially determine the percentage of dwelling units in the state serviced by individual sewage treatment systems and to allocate the same percentage amount for ISTS funding under the water pollution control revolving fund and wastewater infrastructure funding programs; requiring the commissioners of agriculture and the pollution control agency (PCA) to allocate the same percentage amount from the agriculture best management practices and clean water partnership loan programs respectively subject to available appropriations (ra)