Dispersion of Leachate in Aquifers
Abstract
Contaminated dredged material is often placed in confined disposal facilities (CDFs) designed and operated to control environmental impacts of the disposed sediment. A CDF is a diked enclosure having structures that retain dredged material solids. When contaminated dredged material is placed in a CDF, contaminants may be mobilized to form leachate that may be transported to the site boundaries by seepage. The purpose of the research presented here is to examine the components of steady-state leachate attenuation in aquifers and to develop predictive equations of the attenuation for use in a screening tool being developed for the upland testing manual (USACE 2003). The main factors affecting leachate transport and dilution through the saturated zone of an aquifer are evaluated to develop a guidance procedure to assist in decision making regarding the use of leachate controls in the CDF. The U.S. Environmental Protection Agency's (EPA's) MULTIMED model is used to develop predictive equations for the effects of recharge and lateral and vertical dispersion processes on center-line concentrations in the aquifer. Results show that the effects of these processes can be predicted independently. Relationships were developed to estimate the attenuation factor for each process. An equation for center-line leachate concentration using attenuation factors was developed to predict peak leachate exposure for decision making.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2004
- Accession Number
- ADA427516
Entities
People
- N. M. Aziz
- P. R. Schroeder
Organizations
- Engineer Research and Development Center