Final Report: Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill SiteEPA Grant Number: R828771C013
Subproject: this is subproject number 013 , 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: Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill Site
Investigators: MacKay, Allison , Smets, Barth F. , Fairbrother, D. Howard
Institution: University of Connecticut , The Johns Hopkins University
EPA Project Officer: Klieforth, Barbara I
Project Period: October 1, 2001 through September 30, 2007
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management
Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill Site. Allison MacKay (UConn), Barth Smets (UConn), and Howard Fairbrother (JHU). Many industrial and urban sites with subsurface contamination are characterized by shallow aquifers that discharge to nearby surface water bodies. Little is known about how the sharp biogeochemical gradients of the groundwater/surface water interface (GSI) can affect the fate of contaminants. Preliminary observations at the Auburn Road Landfill Superfund site suggest groundwater arsenic transport to the Cohas Brook is controlled by the formation of iron oxides in the sediments. Iron oxidizing bacteria are present in the sediments and may play a central role in generation of iron oxyhydroxide solids because abiotic iron oxidation is extremely slow given the pore water chemistry in the groundwater/surface water interface. The goal of this research project was to identify the seasonal cycle of arsenic sequestration and release between sediments and pore waters in the groundwater/surface water interface.
Spatial heterogeneity of arsenic and iron concentrations in near-shore Cohas Brook sediments were characterized using 3 freeze cores. Two of the three cores showed sharp decreases in arsenic and iron concentrations with depth, while the third core exhibited nearly constant arsenic and iron concentrations with depth. In general, arsenic was strongly sorbed to the surfaces of amorphous iron oxides in the sediments. High numbers of iron oxidizing bacteria were detected in the shallow regions of the cores. The abundance of iron oxidizing bacteria declined by nearly 2 orders of magnitude at 15 cm below the ground surface where the iron concentration was only 10% of the value observed at shallower depths. A quantitative method to measure the cellular activity of iron oxidizing bacteria in sediments was developed. Chemical characterization of solids from the top 10-cm of a core obtained from a location 2-m from the water line showed arsenic to be concentrated in regions of high iron, and not found in regions depleted of iron. The results demonstrate that the GSI may be an effective barrier for off-site transport of groundwater contaminants when seasonal oxic conditions promote iron oxide formation and contaminants have sorption affinity on oxide surfaces. A final observation is that biologically mediated iron-oxide formation may enhance the thickness of the iron oxide-rich zone.
The final research project collected information on the research needs in EPA Regions 1, 2, and 3.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
|Other subproject views:||All 14 publications||2 publications in selected types||All 2 journal articles|
|Other center views:||All 108 publications||22 publications in selected types||All 20 journal articles|
|| Gan P, Yu R, Smets BF, MacKay AA. Sampling methods to determine the spatial gradients and flux of arsenic at a groundwater seepage zone. Environmental Toxicology and Chemistry 2006;25(6):1487-1495.
|| Yu R, Gan P, MacKay AA, Zhang S, Smets BF. Presence, distribution, and diversity of iron-oxidizing bacteria at a landfill leachate-impacted groundwater surface water interface. FEMS Microbiology Ecology 2010;71(2):260-271.
Supplemental Keywords:air quality, groundwater contamination, organics, metals, hyporheic zone, TOSC, TAB, outreach projects, Brownfields,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Waste, POLLUTANTS/TOXICS, Environmental Chemistry, Chemicals, Hazardous Waste, Ecological Risk Assessment, Hazardous, Environmental Engineering, contaminated sediments, hazardous waste disposal, hazardous waste management, hazardous waste treatment, contaminated waste sites, fate and transport , landfills, contaminated groundwater, chemical releases, hazardous waste characterization, arsenic, heavy metals, groundwater
Progress and Final Reports:Original Abstract
Main 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