Field evaluation of arsenic transport across the groundwater/surface water interface: Groundwater discharge and iron oxide precipitation

GEOC 124

Robert G. Ford, ford.robert@epa.gov1, Kirk G. Scheckel, Scheckel.Kirk@epa.gov1, Steven Acree, acree.steven@epa.gov2, Randall Ross, ross.randall@epa.gov2, Bob Lien, lien.bob@epa.gov1, Patrick Clark, clark.patrick@epa.gov1, and Brad Scroggins, scroggins.brad@epa.gov2. (1) Land Remediation and Pollution Control Division, U.S. Environmental Protection Agency, 26 W Martin Luther King Dr, Cincinnati, OH 45268, (2) Ground Water and Ecosystems Restoration Division, U.S. Environmental Protection Agency, 919 Kerr Research Dr, Ada, OK 74820
A field investigation was conducted to examine the distribution of arsenic in ground water, surface water, and sediments at a Superfund Site in the northeastern United States (see companion presentation by K. G. Scheckel et al). Ground-water discharge into the study area was characterized as having high ferrous iron and arsenic concentrations. Patterns in ground-water discharge were assessed via a network of vertically-nested wells, piezometers, and seepage meter deployments to map out small scale variations in discharge into the surface water body. These ground-water measurements were supplemented with vertical profiling of surface water chemistry and evaluation of arsenic sequestration during iron oxide precipitation at the sediment-water interface. The mineralogy of iron oxide precipitates was determined along with in-situ arsenic sorption characteristics. This information will be employed to inform decisions on the design of appropriate remedies to address the cleanup of ground water and sediments at the site.
 

Speciation of Arsenic and Other Trace Elements in Soils and Sediments
1:25 PM-5:10 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 211, Oral

Division of Geochemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008