Projects details

Excavation, Ex-Situ and In-Situ Chemical Oxidation, Reuse of Soils on Site and Wetlands Recontruction


Location: Morris Plains, New Jersey
Value: $ 7,200,000.00
Soils and groundwater at the site had become contaminated with levels of perchloroethylene (PCE) and trichloroethylene (TCE) at concentrations in excess of 20,000 mg/kg combined, significantly above risk-based remedial standards. Because the PCE and TCE in soil presented an ongoing source of groundwater contamination, soil remediation was a top remedial priority at the site. The initial unsaturated soil remedy proposed for this site included in-situ, enhanced anaerobic reductive dehalogenation. However, due to heterogeneous soils, which included a significant amount of clay and a depth to groundwater greater than 35 feet below grade, the in-situ anaerobic technology was challenged by the NJDEP. Working with the client and their engineer, Panther proposed an on-site, ex-situ chemical oxidation approach within specially constructed treatment cells including a 150,000 cubic foot negative pressure structure mounted on rails. Other major components of this complex project included steel sheet piling, dewatering, water storage and treatment, vapor control and treatment, perimeter and work zone air monitoring, sewer line and water main relocation, streambed re-routing, backfilling, capping and restoration of 7 acres of wetlands areas including the planting of 4,500 wetland trees and plants. Panther implemented a Fentonís based catalyzed persulfate technology to remediate 55,000 tons of contaminated soils containing approximately 32,000 lbs of contaminants at the site. After extensive in-house bench-scale testing of different oxidation technologies a new combination of oxidants was developed and implemented at the site to achieve remedial objectives. Following excavation, chemical oxidation and mixing, an extensive post-treatment soil sampling quality assurance plan was implemented to ensure soils met the re-use criteria of less than 5 mg/kg. Ninety percent (90%) of all treated soils met the reuse requirement. Prior to use a backfill, oxidized soils were further stabilized with pozzolanic materials in order to achieve compaction requirements. During demobilization after completion of the ex-situ treatment, Pantherís field team discovered a previously undetected surface impoundment containing significant concentrations of the same chlorinated solvents. Working in partnership with our customer and their engineer, Panther developed a plan to remediate the additional area. As the ex-situ treatment cells had been dismantled, Panther mobilized our specialized in-situ power mixer to simultaneously mix and inject the selected oxidants. In this manner the final 15,000 tons of soils were treated in place. The ex-situ and in-situ chemical oxidation technologies designed and implemented by Panther were aggressive approaches specifically designed to achieve mass removal of PCE and TCE to below site-specific treatment standards and allow re-use of the treated soil on-site as fill. The entire project was expedited due to an impending real estate transaction. Pantherís approach not only achieved closure in a compressed time frame, but also saved the client millions of dollars in potential disposal costs.

Additional Views

task_13.jpg Task 13c x_01232009_094250.jpg Task 13a x_01232009_094504.jpg

Back to Project Listings
© Panther Technologies, Inc. All rights reserved. Sitemap Sitemap