NAPL Occurrences at an Industrial Site: Creosote or Petroleum Hydrocarbons?

摘要

A creosote bulk storage and transfer facility operated for at least 60 years (until the early 1990’s) on real estate leased from a railroad. The former facility (the Site) and surrounding properties have over a century of industrial use including large volume bulk storage of petroleum hydrocarbons such as No. 6 (heavy) fuel oil. Creosote storage occurred locally at the Site. Over the years differing non-aqueous phase liquid (NAPL) products have co-mingled on the Site, posing the need for differentiation between hydrocarbons common to both petroleum and creosote. In 2013 and 2016, known creosote source samples were collected from monitoring and recovery wells and soil. These samples were intended to provide comparison with property line locations that are potentially affected by petroleum (suspected No. 6 fuel oil) and/or creosote. Forensic analyses include GC/FID chromatograms, GC/MS biomarker analysis and extended PAH analysis. Each set of data revealed diagnostic characteristics of the products of interest. Combined with Site and surrounding facility operational history and hydrogeology, it was concluded that petroleum product (No. 6) fuel was present in property line wells and was believed to originate from the neighboring facility. The study not only supported liability allocation issues, but also contributed to understanding the dissolved phase plume characteristics.