A little-known change to state laws governing stormwater runoff and erosion and sediment control has several major construction projects tied up in Mecklenburg County. The expansion of Meadowview Terrace in Clarksville and the installation of a convenience center near South Hill are on hold for now, while contractors wait for the county and state to approve their plans for managing stormwater and erosion at the construction sites, according to Robert Hendrick, Mecklenburg County's zoning administrator.