This project produced a user's guide that shows how to use tree cores as a reconnaissance tool to find subsurface volatile organic plumes. The document provides a description of the strengths and limitations of the tree coring method as well as the preferred approach for collecting the data. This method may be useful in measuring the potential or effectiveness of phytoremediation, as well as studying vapor-intrusion into buildings.

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This manual provides a guide to the use of tree coring as a tool to examine subsurface VOCs. It examines some of the factors influencing the use of tree coring for that purpose and summarizes some case studies in which tree coring has been used to examine subsurface VOCs. Typical VOCs that have been detected in tree cores include benzene, toluene, ethylbenzene, xylene isomers, trimethyl benzene, MTBE, TCE, PCE, and cDCE. The method is inexpensive, portable, rapid, and uncomplicated. The presence of VOCs in tree cores is a strong indicator of subsurface VOC contamination; however, the lack of VOC detection does not necessarily mean that VOC
contamination is not present.

Tree cores were taken and analyzed from an area near the Nyanza Superfund site in Ashland, MA on August 30, 2006. The analysis showed concentrations of percholoethene ranging from non-detect to 2,557 parts per billion by volume (ppb) and for trichloroethene from non-detect to 424 ppb. An Interim report displaying the data, but with no evaluation, is available on-line (http://www.clu-in.org/programs/21m2/projects/FINAL_Ashland_data_report.pdf). The User's Guide, which provides the methodology for tree coring is also available on-line.

Yes, view at
http://pubs.water.usgs.gov/sir2008-5088