The Mayor’s Office of Environmental Remediation (OER) designs and implements the City’s cleanup and redevelopment initiatives for vacant contaminated land (brownfields). OER runs the NYC Voluntary Cleanup Program, the nation’s only municipally-run cleanup program and the second largest cleanup program in the U.S., and provides remedial oversight and liability protection to property owners and developers of over 300 properties each year. Brownfield redevelopment is complicated by the presence of contamination from prior site uses. OER operates many associated programs, such as the NYC Clean Soil Bank, a soil exchange that reuses clean soil from excavation of new buildings to lower taxpayer costs and improve NYC’s environment. OER also administers the Brownfield Incentive Grant (BIG) program, which provides funding for the investigation and cleanup of brownfield sites and provides grants to community-based organizations conducting planning for vacant land.