ABSTRACT
Natural attenuation involves the use of the natural processes with the soil and groundwater to remediate contamination by physical, chemical, and biological processes to reduce the risk to human health and the environment. Although the use of natural attenuation as a treatment process is increasing for remediation of contaminated groundwater, much less research has focused on contaminated soils and sediments. Industrial efuents, agricultural runoff, and sewage discharges are major sources of contaminants for the sediments. In addition, benthic organisms can transport contaminants through bioturbation, and there is considerable variability at sites. Organic matter, a particularly important component of the sediments, can sequester the contaminants. Sediment-water partitioning controls the release of the contaminants into pore water and benthic organisms. Fate and transport mechanisms for both organic and inorganic contaminants within the sediments need to be understood to establish protocols for the monitoring and use of natural attenuation.
