In 2007, Session Law 2006-246 expanded stormwater post-construction control requirements into designated Phase II areas, beyond those cities with NPDES Phase II MS4 permits. These areas include certain "tipped counties" , and unincorporated areas that fall within urbanizing areas and "municipal spheres of influence" (MSI) around Phase II cities and towns. This law significantly expanded the area in which NC DEMLR must issue State Stormwater permits for development (see this PDF map of Phase II areas). In 2012, this program was codified in 15A NCAC 2H .1000. Note that some tipped counties are coastal counties where the Coastal Stormwater Rules apply (see the Coastal Counties tab to the left).