Application of Catalyzed Persulfate of Chlorobenzenes in Glacial Till and Bedrock, Corinna, ME

Ian T. Osgerby, PhD PE, USACE, 696 Virginia Rd., Concord, MA 01742, Tel: 978-318-8631, Fax: 978-318-8614, Email: ian.t.osgerby@usace.army.mil
Brant Smith, PhD PE, XDD, 22 Marin Way, Unit 3, Stratham, NH 03883, Tel: 603-778-1100, Fax: 603-778-2121, Email: smith@xdd-llc.com
Scott Crawford, XDD, 22 Marin Way , Unit 3, Stratham , NH 03883 , Tel: 603-778-1100, Fax: 603-778-2121, Email: crawford @xdd-llc.com
Andrew J. Boeckeler, PG, Nobis Engineering Inc., 18 Chenell Dr. , Concord , NH 03301 , Tel: 603-224-4182, Fax: 603-224-2507, Email: ABoeckeler@nobisengineering.com.

Pilot and full scale ISCO tests were carried out at the former Eastland Woolen Mill, Corinna , ME in prior years as part of an overall program to reduce the residual contamination left after an exsitu thermal treatment project was completed.  Approximately 100,000 tons of soil were excavated and treated thermally to reduce the average concentration of chlorobenzenes to below 15 mg/kg prior to backfilling.  Residual contamination existed in untreated soils on-site adjacent to former USTs, a loading dock, and upper burden soils between the excavation and a state highway.  A portion of the upper burden was treated in Phase II pilot and full scale tests after selecting a preferred oxidant to use at this site. The residual contamination at the USTs and former loading dock were treated in a Phase I ISCO project.  Residual contamination in the lower till burden and shallow weathered bedrock was subsequently addressed with catalyzed persulfate injection in Phases II and III.  A unique aspect of this project was the bath tub shape between the subsurface below an existing road down to the upper bedrock and the face of the former excavation now .  The lower soil and upper bedrock first had to be dewatered to allow the chemicals to be drawn into and flooding the shallow bedrock prior to completing the ISCO in the soils above.  The final injection campaign concluding the remediation of chlorobenzenes in the burden and shallow bedrock at this site is described.  In addition the presence and treatment of chloromethanes and, as expected, acetone, etc. oxidation byproducts, residual contaminant concentrations and rebound is discussed.  The results of a Phase IV pilot test in the bedrock fractures are also described.  Prospects for a successful full scale application for the untreated, contaminated bedrock fracture zones is discussed , but is dependent on available funding.