Understanding Remediation at Contaminated Sediment Sites: Advantages, Limitations, and Risks Associated with Sediment Management Options
Steven C. Nadeau, J.D., Honigman Miller Schwartz and Cohn LLP, Detroit , MI  
Megan C. McCulloch, J.D., M.S., Honigman Miller Schwartz and Cohn LLP, Detroit , MI

A Simple Restoration-based Approach to Estimate Potential Natural Resource Damages at Contaminated Sediment Sites
Timothy R. Barber, Ph.D., ENVIRON International Corporation, Burton , OH

GE Hudson River Sediment Processing Facility Design Overview
Scott R. Blaha, P.E., General Electric Company, Ft. Edward, NY
Joseph J. Corrado, P.E., BCEE, ARCADIS, Mahwah, NJ

Innovative Site Characterization Tools Establish Sediment Remediation Goals at a Former Manufactured Gas Plant Site
Russell A. Johnson, AMEC Earth & Environmental, Inc., Westford , MA
Robert Cleary, Bay State Gas Company, Westborough , MA
Peter LaGoy, Bay State Gas Company, Westborough , MA

Comparison of Site-Specific Sediment Benchmarks to Screening Criteria at a Former MGP Site in Massachusetts
Allison Nightingale, AMEC Earth & Environmental, Inc., Westford, MA
Paul Anderson, AMEC Earth & Environmental, Inc., Westford, MA
Kevin Haines, AMEC Earth & Environmental, Inc., Westford, MA
Robert Cleary, Bay State Gas Company, Westborough, MA
Peter LaGoy, Bay State Gas Company, Westborough, MA
Nick Azzolina, ENSR, Ithaca, NY

Quantifying the Bias in Sediment Concentration Monitoring in Surface Water Runoff
Student Presenter
George D. Fowler, Graduate Research Assistant, Water Resources, Department of Civil Engineering, University of New Hampshire, Durham, NH 
Sebastien Piney, Visiting Scholar
Robert M. Roseen, Director, The UNH Stormwater Center , Ph.D., Department of Civil Engineering, University of New Hampshire , Durham , NH
Thomas P. Ballestero, Associate Professor, Civil Engineering, P.E., Ph.D., P.H., C.G.W.P., P.G., Department of Civil Engineering; Principal Investigator, The UNH Stormwater Center, University of New Hampshire, Durham, NH
James Houle, Facility Manager, The UNH Stormwater Center, M.A., C.P.S.W.Q., University of New Hampshire, Durham, NH

Importance of Source Control:  Recontamination of Completed Sediment Remedial Projects
Steven C. Nadeau, J.D., Honigman Miller Schwartz and Cohn LLP, Detroit, MI  

Understanding Remediation at Contaminated Sediment Sites: Advantages, Limitations, and Risks Associated with Sediment Management Options
Steven C. Nadeau, J.D., Honigman Miller Schwartz and Cohn LLP, 660 Woodward Avenue, Detroit, MI  48226, Tel: 313-465-7492, Fax: 313-465-7493, Email: snadeau@honigman.com
Megan C. McCulloch, J.D., M.S., Honigman Miller Schwartz and Cohn LLP, 660 Woodward Avenue, Detroit, MI  48226, Tel: 313-465-7444, Fax: 313-465-7445, Email: mmcculloch@honigman.com

At many contaminated sediment sites, lack of stakeholder awareness of the advantages, limitations, and risks of the three major sediment management options (dredging, in-situ capping, and monitored natural recovery) and misperceptions about their effectiveness and permanence pose a major barrier to selecting remedies that effectively combine sediment management options to reduce risks to human and ecological receptors.  To overcome this serious impediment, stakeholders should be educated about remedy selection principles and the advantages, limitations and risks of dredging, in-situ capping and monitored natural recovery as early as possible in the site investigation and remedy selection process.  This presentation highlights key remedy selection principles, provides an overview of the advantages, limitations, and risks associated with dredging, in-situ capping, and monitored natural recovery, illustrates comparisons of the net effectiveness of remedial alternatives, and discusses lessons learned from prior experiences with each sediment management option.

A Simple Restoration-based Approach to Estimate Potential Natural Resource Damages at Contaminated Sediment Sites
Timothy R. Barber, Ph.D., ENVIRON International Corporation, 13801 W. Center St, P.O. Box, 405, Burton, OH 44021, Tel: 440-834-1460, Fax: 440-834-1560, Email:tbarber@environcorp.com.

The environmental liability associated with potential natural resource damage claims is poorly understood, both from a probability of occurrence and total economic value perspective. It is abundantly clear, however, that state and federal Trustees are actively pursuing hundreds of claims associated with contaminated sediment. These claims tend to focus on rivers, lakes, and coastal and marine environments impacted by bioaccumulative, persistent, and toxic compounds, such as PCBs, dioxins and furans, mirex, dieldrin, DDTs, chlordane, and mercury. Based on key site characteristics and readily available information, a restoration-based valuation method is used to estimate the range of service losses reasonably expected at the site. These service losses are monetized using generic unit costs for various restoration alternatives. Although actual natural resource damage claims are subject to a myriad of complicating factors, this approach is simple, quick, and can provide a reasonable and customary estimate of the potential environmental liability associated with a hypothetical natural resource damage claim. In addition, the probability of occurrence is estimated based on regulatory status, geographic location, public awareness, and perceived value of potentially impacted natural resources. This presentation will provide an overview of the methodology, provide several example calculations, and quantify uncertainty by comparing the predicted liability with actual settled cases.

GE Hudson River Sediment Processing Facility Design Overview
Scott R. Blaha, P.E., General Electric Company, 381 Broadway, Bldg. 40-2, Ft. Edward, NY 12828, Tel: 518-746-5296, Fax: 518-746-5703, Email: scott.blaha@ge.com
Joseph J. Corrado, P.E., BCEE, ARCADIS, 1 International Blvd., Suite 406 , Mahwah , NJ 07495 , Tel: 201-684-1410, Fax: 201-684-1420, Email: joseph.corrado@arcadis-us.com

In 2002, EPA issued a Record of Decision to dredge sediment, containing PCBs, from the Hudson River .  The ROD specified that the project be completed in two phases, with Phase 1 encompassing the first year of dredging (removing 200,000 to 265,000 cubic yards), followed by an evaluation to see if changes need to be made before proceeding with Phase 2.  Dredging of an additional 1.6 million cubic yards over a 5-year period is planned for Phase 2.

The design for Phase 1 specifies mechanical dredging and transport of sediment by barge to a processing facility.  The purpose of the processing facility is to offload sediment from barges, separate coarse material from the dredged sediment, and dewater the sediment.  The facility is designed to process the range of sediment observed in over 9,000 sediment cores collected during the field investigation. 

This presentation will discuss the general design components associated with the processing facility, including:  a barge unloading wharf, size separation equipment (trommel screen and hydrocyclone system), sediment thickening, twelve (12) 2-meter by 2-meter filter presses for dewatering.  The filtrate from the filter presses, and stormwater from areas managing sediment will be treated at a 2 MGD water treatment plant, which includes clarification, filtration and activated carbon.

Materials staging areas were also designed to stage dewatered filter cake, coarse materials and debris prior to be loaded onto rail cars for final disposal.  The rail yard consists of a loading platform for over 40 gondola cars and nearly six miles of new track to assemble 81-car unit trains and receive empty train sets returning from the disposal facility.

The site for the processing facility started out as 110 acres of open land with no infrastructure, no access road or river access, and no utilities.  The site is being transformed into a modern industrial facility.  Construction of the processing facility began in April 2007 and commissioning is planned for the fall of 2008.  During Phase 1 dredging, the plant will operate 24 hours per day, 6 days per week, from May to November. 

Innovative Site Characterization Tools Establish Sediment Remediation Goals at a Former Manufactured Gas Plant Site
Russell A. Johnson, AMEC Earth & Environmental, Inc., 2 Robbins Road , Westford , MA 01886 , USA ,Tel: 978-245-6606, Fax: 978-245-6633 , Email: Russell.Johnson@amec.com
Robert Cleary, Bay State Gas Company, 300 Friberg Parkway, Westborough , MA 01581, USA , Tel: 508-836-7275, Fax: 508-836-7073, Email: RCleary@nisource.com
Peter LaGoy, Bay State Gas Company, 300 Friberg Parkway , Westborough , MA 01581, USA , Tel: 508-836-7263, Fax: 508-836-7073 , Email: PLaGoy@nisource.com

The former Springfield Gas Works occupied three city blocks near the Connecticut River in Springfield , Massachusetts .  Investigations indicated potential subsurface seepage of coal tar to the river.  A diving/video inspection of the riverbed revealed a surficial deposit of hardened tar approximately 400 feet long and 50 feet wide. Traditional and innovative technologies, including TarGOST (tar-specific green optical scanning tool), vibracore, forensic hydrocarbon chemistry, physical testing, and mussel counts were combined to assess possible modes of tar deposition and potential future migration.

TarGOST borings were advanced to rapidly screen the distribution of tar, including non-aqueous phase liquids (NAPL) at depth, over a large area. Vibracores were then advanced to sample tar-affected sediment for analysis of mono- and polynuclear aromatic hydrocarbons (MAHs/PAHs), including alkylated PAHs, to discern source type (i.e., petrogenic vs. pyrogenic).  Undisturbed samples were collected for UV and white light photography.  Core sub-samples were tested using a centrifuge method at incremental G forces for water and NAPL saturations and to assess mobility.  Mussel counts, size and age were evaluated to assess sediment stability and potential adverse affects of sediment remediation technologies.

The chemistry data identified two tar types generated at different times at the plant.  Based on the spatial distribution of tars in land borings and sediment samples it appears that tar was discharged to the river from pipes, with minor contributions from subsurface seepage, limiting the scope of land-side remediation efforts.  Centrifuge data indicate that tar in sediment meets the regulatory definition of NAPL; however, this material is pooled in clay depressions and has limited mobility.  Natural processes have covered much of the tar with sediment having very low MAH/PAH concentrations that support mussel communities. The extent of sediment remediation and potential for adverse environmental affects will be weighed against the benefits of tar removal from the river.

Comparison of Site-Specific Sediment Benchmarks to Screening Criteria at a Former MGP Site in Massachusetts
Allison Nightingale, AMEC Earth & Environmental, Inc., 2 Robbins Road, Westford , MA 01886 , USA , Tel: 978-245-6606, Fax: 978-245-6633, Email: allison.nightingale@amec.com
Paul Anderson, AMEC Earth & Environmental, Inc., 2 Robbins Road, Westford , MA 01886 , USA , Tel: 978-245-6606, Fax: 978-245-6633, Email: paul.anderson@amec.com
Kevin Haines, AMEC Earth & Environmental, Inc., 2 Robbins Road, Westford , MA 01886 , USA , Tel: 978-245-6606, Fax: 978-245-6633, Email: kevin.haines@amec.com
Robert Cleary, Bay State Gas Company, 300 Friberg Parkway, Westborough , MA 01581 , USA , Tel: 508-836-7275 , Fax: 508-836-7073 , Email: RCleary@nisource.com
Peter LaGoy, Bay State Gas Company, 300 Friberg Parkway, Westborough , MA 01581 , USA , Tel: 508-836-7263, Fax: 508-836-7073, Email: PLaGoy@nisource.com
Nick Azzolina, ENSR, 1001 W. Seneca St., Suite 204 , Ithaca , NY 14850 , USA , Tel: 607-277-5716 , Fax: 607-277-9057 , Email: Nazzolina@ensr.aecom.com

The former Springfield Gas Works occupied three city blocks near the Connecticut River in Springfield , Massachusetts . As part of the river investigation, bulk sediment and sediment porewater were analyzed for polynuclear aromatic hydrocarbons (PAHs) as well as other constituents.  Sediment was also analyzed for total organic carbon and soot carbon.   In addition, whole sediment toxicity was investigated using 28-day Hyalella azteca and 20-day Chironomus dilutus bioassays.  A variety of dose-response analyses were conducted to examine the relationship between sediment toxicity and the concentration of PAHs in sediments and porewater, including the calculation of Toxic Units (TU) using the United States Environmental Protection Agency (USEPA) equilibrium partitioning methodology. 

Toxicity increased with increasing PAH concentration in sediment and porewater.  Accounting for carbon content and type generally improved the dose-response relationship.  By establishing a dose-response relationship we were able to derive site-specific sediment benchmarks protective of benthic invertebrates for both individual and total PAHs.  These sediment benchmarks are substantially higher than those established by the Massachusetts Department of Environmental Protection (MADEP) but are consistent with allowable concentrations observed in other sediments where PAHs are primarily of pyrogenic origin. 

The availability of porewater data at this site allows for derivation of site-specific sediment organic carbon to porewater partition coefficients (Kocs).  Site-specific Kocs are substantially larger than United States Environmental Protection Agency (USEPA) default Kocs, suggesting the absence of toxicity at many locations is due to lower bioavailability of PAHs than assumed by USEPA’s default equilibrium partitioning assumptions.