Baseline Study of Trace Metal Concentrations in Soils of Atlantic City, NJ
Claudia Dengler, The Richard Stockton College of New Jersey, Pomona, NJ  
Heather Mortensen, The Richard Stockton College of New Jersey, Pomona, NJ
Tait Chirenje, The Richard Stockton College of New Jersey, Pomona, NJ  

Evaluation of Reactive Materials for Remediation of Heavy Metal-Contaminated Ground Water
Pamela J. Dugan, Carus Corporation, Peru, IL                        

Remediation of a Hexavalent Chromium Release to Groundwater Using Ion-Specific Resins
Nancy E. Milkey, Tighe & Bond, Westfield, MA 
Isabel F. McCauley, Tighe & Bond, Worcester, MA

From Flask to Field:  Lessons for Transferring Remediation Technology to Contaminated Sites
Karen L. Skubal, U. S. Department of Energy, Washington, DC
Skip Chamberlain, U. S. Department of Energy, Washington, DC

Attenuation Processes for Metals and Radionuclides
Dib Goswami, Washington State Department of Ecology, Richland, WA
Carl Spreng, Colorado Department of Public Health and Environment, Denver, CO   
Karen Vangelas, Savannah River National Laboratory, Aiken SC

Laboratory Investigation of Solubility Control for a Mercury Groundwater Plume
Talaat Balba, Conestoga-Rovers & Associates, Niagara Falls, NY
Sophia Dore, Conestoga-Rovers & Associates, Niagara Falls, NY
Donald Pope, Conestoga-Rovers & Associates, Niagara Falls, NY
Leah Pabst, Conestoga-Rovers & Associates, Niagara Falls, NY
Christa Nunn, Conestoga-Rovers & Associates, Niagara Falls, NY
Alan Weston, Conestoga-Rovers & Associates, Niagara Falls, NY

Baseline Study of Trace Metal Concentrations in Soils of Atlantic City, NJ

Student Presenter

Claudia Dengler, Environmental Science, The Richard Stockton College of New Jersey, P.O. Box, Pomona, N.J. 08240, USA, Tel: 609-668-4385, Email: stk35575@go.stockton.edu
Heather Mortensen, Environmental Science, The Richard Stockton College of New Jersey, P.O. Box, Pomona, N.J. 08240, USA, Tel: 973-641-9872, Email: stk34592@go.stockton.edu
Tait Chirenje, Environmental Science, The Richard Stockton College of New Jersey, P.O. Box, Pomona, N.J. 08240, USA, Tel: 352-514-6379, Email:  tait.chirenje@stockton.edu

Baseline trace metal concentrations in New Jersey urban areas, specifically South Jersey, are not well documented.  Trace metals are a concern because many are persistent and bioaccumulative.  Even those that are not bioaccumulative are often harmful at very low concentrations.  Specific adverse effects on human health include acting as neurotoxins, carcinogens, mutagens, endocrine disruptors, and causing deficiencies in other nutrients.

This study will determine baseline concentrations of trace metals for three land uses; commercial, residential, and parks.  The trace metals are mercury, arsenic, lead, nickel, copper, chromium, cadmium, and selenium. 

One hundred and ten surface soil samples were collected, dried, sieved, and digested using USEPA method 3050B and analyzed by graphite furnace atomic absorption using USEPA method 7060A.  Preliminary results show little difference in trace metal concentrations between the land uses. The complete spatial distribution will be mapped in a GIS program to show any correlation between development, land use, and concentrations. 

This study is significant because baseline values help to judge pollution changes over time, set regulation limits, and help with risk-based, site-specific remediation of which none of these could be accurately determined without a reference point of baseline concentrations.

Evaluation of Reactive Materials for Remediation of Heavy Metal-Contaminated Ground Water
Pamela J. Dugan, Ph.D., P.G., Carus Corporation, 315 5th Street Peru, IL  61354, Phone: 815-224-6870, Fax: 815-224-6896 

Significant efforts have been undertaken to evaluate different amendment materials for in situ remediation of metal-contaminated ground water. Reductions in metal concentrations in solution can be achieved by: (1) increasing metal adsorption, (2) entrapment of metals in crystal lattices, which may be important for materials containing hydrous oxides and, (3) precipitation/co-precipitation of soluble metals. A laboratory investigation was conducted to assess the feasibility of immobilizing heavy metals using a number of reactive materials including lime, zero valent iron, activated red mud, ferric chloride (FeCl₃), and calcium polysulfide. The effect of a number of parameters on metal removal will be investigated in laboratory experiments including pH, temperature, heavy metal concentration, and concentration of reactive material. Results regarding the ability of a variety of amendments and combinations of amendments to immobilize metals as a function of pH, temperature, as well as metal and reactive material concentrations will be presented.

Remediation of a Hexavalent Chromium Release to Groundwater Using Ion-Specific Resins

Nancy E. Milkey, P.G., LSP, Tighe & Bond, 53 Southampton Road, Westfield, MA 01085, 413- 572-3273
Isabel F. McCauley, Tighe & Bond, 446 Main Street, Worcester, MA 01608, Tel: 508-471-9635 

In March 1986, during installation of a monitoring well at an industrial electroplating facility a chrome rinse line was pierced by an auger.  A six-inch recovery well was installed in the borehole at the release point and the recovered groundwater was pumped directly into the facility’s wastewater treatment plant.  In 1998, a site assessment identified elevated hexavalent chromium concentrations in groundwater in this area of the site.  The assessment included the installation of monitoring wells which were sampled over several years.  The data indicated that the concentrations in this area of the site were increasing.  Additional investigations, conducted upgradient of the process line release, identified another source of hexavalent chromium – one of the platers inside the building.

A remediation system was designed to remediate the hexavalent chromium release which included the installation of five recovery wells and associated piping.  In Fall 2006, step tests were conducted to determine the approximate pumping rate for the recovery wells.  Based on the results of the test, pumping rates of up to four gallons per minute were included in the design. 

A pilot test was subsequently conducted to confirm that the proposed treatment process, utilizing ion-specific exchange filters, was appropriate for the removal of hexavalent chromium and nickel.  In addition, the data from the pilot test was used to determine the anticipated frequency of greensand filter backwash and change-out frequency for the resin containing hexavalent chromium.

The system was installed during Spring-Summer 2008 and includes three hexavalent chromium-specific resins and two nickel-specific resins in a remediation building at the site. The majority of the treated effluent is recharged upgradient of the system into a recharge pit to enhance flushing of the aquifer.  The remainder of the treated effluent is discharged to the municipal sewerage system under a municipal Industrial Pretreatment Permit.

From Flask to Field:  Lessons for Transferring Remediation Technology to Contaminated Sites

Karen L. Skubal, U. S. Department of Energy, Office of Groundwater and Soil Remediation, 1000 Independence Ave., SW, Washington, DC 20585 USA.  Tel: 301-903-6524, Fax: 301-903-3617, Email: karen.skubal@em.doe.gov
Skip Chamberlain, U. S. Department of Energy, Office of Groundwater and Soil Remediation, 1000 Independence Ave., SW, Washington, DC 20585 USA.  Tel: 301-903-7248, Fax: 301-903-3617, Email: grover.chamberlain@em.doe.gov

Hexavalent chromium, Cr(VI), was discovered in 1995 in groundwater along the Columbia River at the 100-D Area of the Hanford Site near Richland, Washington.  Contamination arose from the use of sodium dichromate as a corrosion inhibitor in cooling water for nearby plutonium production reactors, which operated between 1944 and 1967.  Following the discovery, laboratory research and a field-scale treatability test were initiated to assess in situ redox manipulation (ISRM) for converting Cr(VI) to less toxic, less mobile trivalent chromium.  ISRM uses subsurface injection of strong reducing chemicals to create a permeable aquifer zone for remediating redox-sensitive species in groundwater.  During the field test, sodium dithionite was injected at five wells to create a reduced region 46 m (151 ft) long and 15 m (49 ft) wide.  Naturally-occurring iron(III) was reduced to iron(II), providing the primary reduction capacity for transforming Cr(VI) to the downgradient compliance concentration of 20 µg/L.  Based on the successful treatability study, the relevant interim Record of Decision was amended to select ISRM for plume treatment.  Between 1999 and 2003, a 65-well ISRM barrier was installed along 680 m (2230 ft) of the river.  Its expected lifespan was at least 15-20 years.  By 2004, however, 17 wells within the barrier showed signs of failure, and a planned extension of the barrier was suspended in favor of a supplemental pump-and-treat system.  Two field demonstrations are underway to assess the use of zerovalent iron and biostimulation to restore the barrier’s effectiveness.  This presentation discusses lessons learned from the barrier’s failure and the implications for remediation technology development and environmental decision making.

Attenuation Processes for Metals and Radionuclides

Dib Goswami, Washington State Department of Ecology, 3100 Port of Benton Blvd, Richland, WA 99354 US, Tel: 509-372-7902, Fax: 509-372-7971, Email: dgos461@ecy.wa.gov
Carl Spreng, Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive South, Denver, CO 80246-1530 US, Tel: 303-692-3358, Fax: 303-759-5355, Email: carl.spreng@state.co.us
Karen Vangelas, Savannah River National Laboratory, Bldg. 773-42A, Aiken SC 29808 US, Tel: 803-725-5223 Email: karen.vangelas@srnl.doe.go 

Until recently, there has been little regulatory guidance to support attenuation–based remedies for groundwater contaminated with radionuclides and metals.  This has contributed to inconsistent application of those remedies and generally discouraged their consideration.  The net result is that many sites face intractable closure problems.  EPA recently issued the first two volumes of technical guidance that specifically address monitored natural attenuation (MNA) of inorganic contaminants.  A third volume will address MNA of specific radionuclides.  These new documents provide technical information related to the dominant attenuation mechanisms and methods for characterization and evaluation of specific inorganic contaminants and radionuclides 

Attenuation-based remedies for metals and long-lived radionuclides rely primarily on immobilization of contaminants as stable and/or nontoxic species.  This stabilization and toxicity reduction can result from natural processes, geochemical gradients, or biogeochemical manipulation.  Except for a few radionuclides, the original contaminant remains in the subsurface so that documentation of the sustainability, or permanence, of stabilization and detoxification is crucial to assessing performance.  Another challenge in applying the existing and emerging guidance is the need to simultaneously address multiple contaminants at a target site. 

The Interstate Technology and Regulatory Council (ITRC) is developing technical and regulatory guidance to facilitate implementation of the new EPA guidance for MNA of metals and radionuclides.  This framework will provide a consistent basis for states, stakeholders, federal agencies, and site owners to evaluate and implement attenuation-based remedies.  Additionally, an enhanced attenuation strategy will support instances where actions may be needed to support long-term sustainability of the natural attenuation mechanisms.  The outcome of these efforts is a process that will encourage regulatory cooperation and expedite cleanup.

Laboratory Investigation of Solubility Control for a Mercury Groundwater Plume

Talaat Balba, Ph.D., Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: tbalba@craworld.com
Sophia Dore, Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: sdore@craworld.com
Donald Pope, Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: dpope@craworld.com
Leah Pabst, Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: lpabst@craworld.com
Christa Nunn, Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: cnunn@craworld.com
Alan Weston, Conestoga-Rovers & Associates, 2055 Niagara Falls Boulevard, Suite 3, Niagara Falls, NY 14304, Tel: 716-297-6150, Fax: 716-297-2265, Email: aweston@craworld.com

Groundwater at a chemical plant is contaminated with high levels of chloride and mercury. The ability to control the solubility of mercury in the groundwater is crucial to controlling exposure to the mercury.  The effect of chloride on mercury solubility and the use of abiotic reducing agents to precipitate mercury were investigated in the laboratory as methods of controlling migration of the mercury contaminated groundwater.

Mercuric chloride is soluble in water whereas elemental mercury is not very soluble.  Chloride levels in the groundwater were manipulated to determine whether high chloride levels could convert relatively insoluble elemental mercury to soluble mercuric chloride and conversely, whether low chloride levels could convert soluble mercuric chloride to insoluble elemental mercury.  The results showed that chloride levels above 12,000 mg/L had the potential to convert elemental mercury into mercuric chloride.  The conversion of mercuric chloride to elemental mercury was not observed in low chloride groundwater, however, it was observed in distilled water. 

Redox manipulation involves the injection of a chemical reducing agent to alter the oxidation reduction potential of groundwater or sediment. Previous studies have indicated that low redox conditions in the presence of sulfur in water are expected to result in the precipitation of mercury as a mercury-sulfur compound. It is expected that this method would control the migration of mercury contaminated groundwater by lowering the dissolved mercury concentration. 

Bench scale treatability tests were performed using various sulfur containing compounds to assess the ability of each reducing agent to reduce mercury concentrations in the site soil and groundwater. Greater than a 99% reduction in aqueous mercury concentration was observed with some of the reagents tested.  Sodium sulfide and calcium polysulfide achieved the greatest reductions in soluble mercury levels.  

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