Development of Arsenic Sediment Quality Criteria using Equilibrium Partitioning

EPA Grant Number: R830844
Title: Development of Arsenic Sediment Quality Criteria using Equilibrium Partitioning
Investigators: Visviki, Ioanna , Farley, Kevin J. , Judge, Michael L. , Mahony, John D.
Current Investigators: Visviki, Ioanna , Carbonaro, Richard F. , Judge, Michael L. , Mahony, John D.
Institution: College of Mount Saint Vincent , Manhattan College
Current Institution: College of Mount Saint Vincent
EPA Project Officer: Carleton, James N
Project Period: June 27, 2003 through June 26, 2005 (Extended to June 26, 2006)
Project Amount: $389,391
RFA: Superfund Minority Institutions Program: Hazardous Substance Research (2002) RFA Text |  Recipients Lists
Research Category: Land and Waste Management , Safer Chemicals , Hazardous Waste/Remediation

Objective:

The purpose of the research project is to test the applicability of the Equilibrium Partitioning (EqP) method for developing sediment quality criteria for arsenic in sediments. Arsenic in aquatic sediments is currently a significant problem at Superfund sites. Based on a query of the EPA Superfund database, there are 142 Superfund sites on the current National Priority List (NPL) list with arsenic contamination in sediments. It is of critical importance, therefore, to have reliable methods for determining the sediment concentrations at which arsenic poses an environmental risk. The EqP method relates the observed toxicity of a chemical in the sediment to the concentration of that chemical in the pore water of the sediment. Thus, the LC50 concentration CLC50– the concentration that causes 50% mortality in the amphipod Leptocheirus plumulosus - will be established using water only exposures. The pore water concentration CPWwill be measured using a diffusion sampler. According to the predictions of the EqP model, we expect that if CPW< CLC50, that is, if the measured pore water concentration is less than the LC50 concentration determined from the water only exposures, then no mortality should be observed.

Approach:

We will test the equilibrium-partitioning model for arsenic via three approaches: (1) 96-h static renewal toxicity tests to determine water-only LC50’s for the marine amphipod Leptocheirus, (2) Microtox screening assays for potential chemical interactions with sulfide compounds, and (3) 10-d spiked sediment tests under oxic and anoxic conditions.

Expected Results:

Arsenic in aquatic sediments is currently a significant problem at Superfund sites. It is of critical importance, therefore, to have reliable methods for determining the sediment concentrations at which arsenic poses an environmental risk. We expect that the Equilibrium Partitioning (EqP) method will reliably predict the quality criteria for arsenite and arsenate anions in sediments. The EqP method will relate the observed toxicity of a chemical in sediment to the concentration of that chemical in the pore water of the sediment. Thus, we will provide EPA with a methodology to set rational and causal criteria for arsenic at Superfund sites.

Publications and Presentations:

Publications have been submitted on this project: View all 17 publications for this project

Supplemental Keywords:

sediments, risk assessment, bioavailability, metals, RFA, Scientific Discipline, Health, Water, Waste, POLLUTANTS/TOXICS, Environmental Chemistry, Contaminated Sediments, Geochemistry, Arsenic, Risk Assessments, Water Pollutants, reservoir sediments, contaminant transport, Superfund sites, contaminated sediment, sediment transport, risk management, EqP, sediment quality survey, superfund site, arsenic mobility, assessment methods, water quality, ecology assessment models, biogeochemistry, water treatment, arsenic exposure, equilibrium partitioning

Progress and Final Reports:

  • 2003 Progress Report
  • 2004 Progress Report
  • Final Report