The Application of Steam-enhanced Extraction for in Situ Remediation of Coal Tar Residues at a Former Manufactured Gas Plant Site

Book excerpt: From the early 19th century to the mid 20th century, manufactured gas plants (MPGs) generated coal tar as a by-product of manufactured gas. Often, when these sites were abandoned, coal tar remained in the structures, including the tar separator, tar wells, and gas holders. Such areas are often targeted for source removal actions, because over the decades during operation and since decommissioning, the coal tar has in many cases migrated from its original locations to deeper and more widespread areas of contamination, while maintaining its properties as a dense non-aqueous phase liquid. Remedial actions at MGP sites typically focus on ex situ remediation of coal tar residues in soil and groundwater.