Beginning early in the 1800s, Americans used coal in a variety of ways, including the manufacture of "town gas" that provided more modern comforts such as lighting and heating. A Manufactured Gas Plant produced "town gas" by roasting coal, coke and/or oil in a closed vessel. The gas was captured and cleaned of impurities before being stored in large cylindrical structures, known as gas holders. Coal tar was created as a byproduct of this process and contained some chemical compounds that are considered hazardous. Town gas was distributed through a network of piping, first for lighting streets, homes and businesses, and then for heating and cooking. The manufactured gas era ended in the mid-1950s, when natural gas became widely available through the interstate pipeline system and a more developed electrical distribution system. In 2012, Delmarva Power began remediation of the former manufactured gas plant property it owns in Wilmington, Del., along the riverfront development area. The cleanup was completed during second quarter 2013. The remediation project used innovative technology to allow the environmental cleanup to be performed in a relatively short time period. The project also reduced the need to excavate contaminated soils, which minimized exposure to site workers, reduced the number of large trucks hauling the material off site and provided a fully compliant level of remediation with state and several environmental agencies. During remediation, 228 tons of scrap metal were recycled from demolition, along with 558 tons of concrete from foundations, and 380 tons of asphalt pavement. Delmarva Power also treated and reused approximately 79,000 gallons of water from dewatering the open excavations-then used that water as part of the remedy (in-situ stabilization).