Schaefer, C., D. Lippincott, K. Hatfield, and H. Klammler.
ESTCP Project ER-201330, 126 pp, 2017

A rapid assessment (RA) protocol was developed in this project to assess the potential effectiveness of in situ treatment by chemical oxidation or bioaugmentation. The RA protocol is intended to assess chlorinated ethene rebound, the potential of naturally occurring dechlorination reactions in low permeability zones, and remedial effectiveness using a pair of closely spaced bedrock wells. The RA technique involves identifying hydraulically conductive fracture zones, flushing contaminant from the fracture zones using water, and then evaluating contaminant rebound within this zone while hydraulically isolating the zone from the surrounding contaminated aquifer. The rate, composition, and isotopic signature of contaminant rebound is then used to evaluate the limits of remedial effectiveness, identify the local source/cause of any observed rebound, and improve the site conceptual model. Work was performed at the former Naval Air Warfare Center (NAWC) in Trenton, New Jersey, as a preliminary test site to develop the methodology. The former Naval Construction Battalion Center (NCBC) Davisville (Calf Pasture Point) in North Kingston, Rhode Island, was used for more quantitative purposes and evaluation of the RA testing protocol during rapid flushing of a TCE-contaminated zone using water spiked with bromide tracer. Results from the second site are the focus of this report. https://www.serdp-estcp.org/content/download/46714/436649/file/ER-201330%20Final%20Report.pdf