Grantee Research Project Results
2002 Progress Report: Geochemistry, Biochemistry, and Surface/Groundwater Interactions for As, Cr, Ni, Zn, and Cd with Applications to Contaminated Waterfronts
EPA Grant Number: R828771C003Subproject: this is subproject number 003 , established and managed by the Center Director under grant R828771
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: HSRC (2001) - Center for Hazardous Substances in Urban Environments
Center Director: Bouwer, Edward J.
Title: Geochemistry, Biochemistry, and Surface/Groundwater Interactions for As, Cr, Ni, Zn, and Cd with Applications to Contaminated Waterfronts
Investigators: Smets, Barth F. , MacKay, Allison , Nikolaidis, Nik
Current Investigators: Smets, Barth F. , MacKay, Allison
Institution: University of Connecticut
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2001 through September 30, 2002
Project Period Covered by this Report: October 1, 2001 through September 30, 2002
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management
Objective:
The overall objective of this research project is to identify and assess the relative importance of the complex and potentially antagonistic microbial and chemical processes that govern the retardation and migration of metals?specifically Cd, Zn, Ni, As, and Cr?from a reduced aquifer zone through the groundwater/surface water interface (GSI) into an adjacent surface water body. The specific objectives of this work are to: (1) determine the significance of dissimilatory sulfate and iron reduction in the immobilization of typical cations and oxyanions; (2) determine the relative significance of microbial and chemical iron oxidation in the GSI; and (3) characterize solid-phase and dissolved heavy metal species in groundwater as a function of location with respect to the reduced or the GSI zones.
Many industrial and urban sites with subsurface contamination are characterized by shallow aquifers that discharge to nearby surface water bodies. In such cases, pore water in the stream or pond sediments contains a mixture of surface water and groundwater and is refered to as the GSI. There is little understanding of the extent to which groundwater contaminants may be immobilized in the GSI or discharged to the surface water column. Studies in Montana have shown that oxygenated, high pH surface water induces precipitation of iron and manganese oxides and sorption of heavy metals from discharging groundwater. Biological processes also may be important in the GSI because of the greater abundance of nutrients in stream sediments than in groundwater zones. Thus, GSI processes may play an important role in attenuating groundwater contaminant discharges to surface water bodies.
Progress Summary:
The proposed experimental approach consists of field observations and controlled laboratory experiments. The progress in each of these two areas is described below:
Field Observation. Field tasks consisted of Geoprobe direct push sampling of pore water and solids in transects across the shoreline at a contaminated waterfront site. A doctoral student (Ping Gan) has primary responsibility for directing field sampling tasks in consultation with principal investigators. The proposed site location in Stratford, CT, was chosen because of the extensive site characterization undertaken by other University of Connecticut researchers, and because of the working relationship between the site owner and the University. Upon review of the site characterization report, this site was deemed to be unsuited for this GSI study because the groundwater plume depth was too great to feasibly sample with the equipment available to us. Therefore, project tasks were revised to include a "Site Evaluation" stage.
Site evaluation is being conducted with the aid of the U.S. Environmental Protection Agency (Dick Willey) and the Connecticut Department of Environmental Protection (Maurice Hamel). The objective of the site selection is to identify potential field sites with differing groundwater and surface water chemistries and to find where groundwater contaminants are known to impact adjacent surface water quality. In this way, this project can focus on biological and chemical processes without extensive hydrologic characterization. Thus, the criteria for site selection include: (1) a review of existing site data noting observations of groundwater seeps and sediment pore water concentrations of contaminants; (2) visual inspection and walk-through; and (3) pore water collection and solids collection using hand-sampling techniques. To date, four potential sites have been identified and reviewed. Two sites have been eliminated from consideration for various reasons. Of the two sites under consideration, one is located in CT, and has been sampled to obtain current groundwater samples and profiles of pore water chemistry through the GSI. Chemical parameter analyses currently are being conducted. The existing site data of the final New England site under consideration are being reviewed. This site appears to have great potential as anecdotal reports of iron precipitation at groundwater seeps in the adjacent river are correlated with arsenic immobilization in the solid phase. Sampling of this site will commence in the coming month after some optimization tests of the push-point pore water samplers are conducted.
Laboratory Studies. Laboratory studies of the types of microbial populations present in solids from the GSI will be undertaken with the specific objectives of identifying impacts of carbon fluxes on microbial processes. A graduate student (Jenna Shea) currently is being trained to conduct microbial assays with 16S rRNA-targeted PCR primers. Isolation of sufficient quantities of DNA from complex environmental samples is a challenge being addressed by Ms. Shea before solid cores are obtained.
Future Activities:
Field Observations. We will collect solid and groundwater samples from both the upgradient and GSI zones of the heavy metal contaminated waterfront site. The tasks will employ both Geoprobe techniques and low-volume push-point samplers. The low-volume push-point samplers are sampling tools recently available to achieve high resolution (cm) pore water profiles that are critical for delineating the GSI location and guiding larger sample collections with traditional techniques. Correlations of pore water and solid phase concentrations of a variety of chemical parameters, including conductivity, dissolved oxygen, pH, iron species, and heavy metals will be used to support laboratory investigations of key GSI processes.
Laboratory Studies. Microcosm tests will be used to determine the significance of dissimilatory sulfate and iron reduction in the direct or indirect immobilization of typical cations and oxyanions and the mobilization of bound arsenic species under reducing conditions. Microcosm studies also will be used to determine the relative significance of microbial and chemical oxidation of iron.
Supplemental Keywords:
groundwater/surface water interface, GSI, metal transport, arsenic, chromate, bacteria, microcosm., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Environmental Chemistry, Geochemistry, Restoration, Hazardous Waste, Bioremediation, Ecological Risk Assessment, Ecology and Ecosystems, Aquatic Ecosystem Restoration, Groundwater remediation, Hazardous, fate and transport, hazardous waste treatment, microbial degradation, decision making, spectroscopic studies, biodegradation, urban environmental, Chromium, microbial breakdown, anaerobic microbial activity, arsenic release, transport models, treatment, Zinc, aquatic ecosystems, environmental rehabilitation, water quality, contaminated groundwater, groundwater contamination, contaminated aquifers, urban environment, cadmium, metal wastes, contaminated waterfront, arsenic, groundwater pollution, metals, groundwater, bacterial degradation, heavy metalsRelevant Websites:
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R828771 HSRC (2001) - Center for Hazardous Substances in Urban Environments Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828771C001 Co-Contaminant Effects on Risk Assessment and Remediation Activities Involving Urban Sediments and Soils: Phase II
R828771C002 The Fate and Potential Bioavailability of Airborne Urban
Contaminants
R828771C003 Geochemistry, Biochemistry, and Surface/Groundwater Interactions
for As, Cr, Ni, Zn, and Cd with Applications to Contaminated Waterfronts
R828771C004 Large Eddy Simulation of Dispersion in Urban Areas
R828771C005 Speciation of chromium in environmental media using capillary
electrophoresis with multiple wavlength UV/visible detection
R828771C006 Zero-Valent Metal Treatment of Halogenated Vapor-Phase Contaminants in SVE Offgas
R828771C007 The Center for Hazardous Substances in Urban Environments (CHSUE) Outreach Program
R828771C008 New Jersey Institute of Technology Outreach Program for EPA Region II
R828771C009 Urban Environmental Issues: Hartford Technology Transfer and Outreach
R828771C010 University of Maryland Outreach Component
R828771C011 Environmental Assessment and GIS System Development of Brownfield Sites in Baltimore
R828771C012 Solubilization of Particulate-Bound Ni(II) and Zn(II)
R828771C013 Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill Site
R828771C014 Research Needs in the EPA Regions Covered by the Center for Hazardous Substances in Urban Environments
R828771C015 Transport of Hazardous Substances Between Brownfields and the Surrounding Urban Atmosphere
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.