06.17.10 XDD IMPROVES REMEDIAL EFFICIENCY & SUSTAINABILITY AT TCA SITE 06.10.10 XDD, LLC ADDRESSES REMEDIAL EFFICIENCY AND SUSTAINABILITY AT AMHERST'S INTERNATIONAL CONFERENCE ON GREEN REMEDIATION 01.15.10 XDD, LLC TO DISCUSS MGP REMEDIATION STRATEGIES AND TECHNOLOGIES AT THE EPRI MGP 2010 SYMPOSIUM 10.14.09 XDD, LLC DISCUSSES ISCO REMEDIATION AT ILLINOIS MGP FORUM 8.26.09 XDD, LLC PROVIDES STRATEGIC ISCO ADVICE IN FMC'S FIELD APPLICATION WEBINAR 4.09.09 XDD, LLC TO UNVEIL 1,4-DIOXANE TREATMENT SUCCESS AT DCHWS CONFERENCE IN PHILLY 1.30.09 Xpert SolutionsTM Newsletter: THE GREEN ISSUE 6.12.08 XDD Offers Remedial Technologies Overview In "MGP 101" Course 5.09.08 XDD Lines Up Some Major Gigs in Monterey (May 19-22) 2.06.08 XDD Gets Tough On TCA In FMC's Latest Peroxygen Talk 1.03.08 XDD Profiled In Environmental Business Journal 10.22.07 EPRI RELEASES XDD'S ISCO EVALUATION FOR MGP SITES 10.01.07 XDD Air Sparging Trench Design Presentation 3.30.07 Spring 2007 XPERT SOLUTIONSTM NEWSLETTER New Study Reveals MGP Solution! Plus more on vapor intrusion, cyanide-impacted soils and in-situ stabilization! And of course the world - nay, universal - premiere of Planet XDD!
3.10.07 |
Omer J. Uppal, Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-778-2121, Email: Uppal@xdd-llc.com Michael C. Marley, Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-778-2121, Email: Marley@xdd-llc.com Dennis Keane, Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-778-2121, Email: Keane@xdd-llc.com Dean Peschel, Project Manager, City of Dover, 288 Central Avenue, Dover, NH 03820, Tel: 603-743-6094, Fax: 603-742-3019, Email: dean.peschel@ci.dover.nh.us An air sparging trench alternative was compared to a capping/pump and treat remedy for groundwater impacted with volatile organic compounds (VOCs) and arsenic constituents of concern (COCs), as specified in a Record of Decision (ROD) at a United States Environmental Protection Agency (USEPA) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) landfill site. The air sparging trench with an engineered backfill material was designed to intercept and treat COCs migrating with groundwater from beneath the landfill. The design and performance evaluation of the trench are presented. The trench was designed to provide in-situ flow-through treatment of VOCs by a combination of volatilization and aerobic biodegradation, and arsenic by precipitation and sorption. Various laboratory and field-scale tests were performed to evaluate the effectiveness of the trench in removing COCs. The results of laboratory, field-scale testing, and a stripping analysis indicated that the trench could remove the majority of VOCs that are present at the site by air sparging. Organic compounds that are not expected to be completely volatilized were projected to degrade by aerobic microorganisms in the oxygenated groundwater within and down-gradient of the trench. Geochemical modeling was performed to evaluate the ability of oxidizing conditions within trench to remove dissolved arsenic from groundwater through co-precipitation and sorption onto iron oxides. The modeling results indicated that oxidizing conditions created in the trench will result in precipitation of dissolved arsenic and other reduced minerals into the void spaces of the trench backfill material, significantly reducing the dissolved arsenic levels down-gradient of the trench. Long-term performance issues (i.e., mineral precipitation and biofouling) observed at other air sparging trenches were evaluated and solutions for such potential issues were incorporated in the design. The air sparging trench alternative evaluation resulted in an amendment of the original ROD with a substantial cost saving to the client. Presenting Author: Omer J. Uppal |