Stabilization and Thermal Treatment for Remediation Of MGP (Manufactured Gas Plant) Sites

摘要

Utilities own or are liable for cleanup of more than 1,500 MGP (manufactured gas plant) sites in the U.S. The sites are contaminated with coal tar from coal-fueled gas works which produced "town gas" from the mid-1800s through the 1950s. Virtually all old U.S. cities have such sites. Many are located in downtown areas, adjacent to rail lines, canals, or harbors because this location allowed easy transport of coal to the gas plant, as well as central distribution of the manufactured gas product throughout the city. Most sites are cleaned up under state regulated programs, with a few sites finding their way into CERCLA/Superfund. The contaminants and methods used for remediation are similar to those used for Superfund clean-ups of coal tar contamination from RCRA regulated wood-treating and coke oven facilities. What triggers site cleanup? Regulatory pressure, sale or merger of utilities, property transfers and re-development, as well as releases to the environment—in particular, via groundwater migration—all play a role. Utilities have varied in their approaches to site cleanup, from "do nothing and hope for the besf to well-planned programs to clean all of a utility's sites on a planned timetable. The later approach reduces the potential for a release, citizen lawsuit or regulatory/public service commission intervention. This paper describes experience with two major treatment methods, stabilization to immobilize the waste, and high-capacity thermal desorption to remove and destroy it. Cost data and case studies are provided for both technologies.