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Beneficial Use of Dredge Materials for Soil Reconstruction and Development of Dredge Screening Protocols
Author(s) -
Koropchak Sara C.,
Daniels W. Lee,
Wick Abbey,
Whittecar G. Richard,
Haus Nick
Publication year - 2016
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2014.12.0529
Subject(s) - environmental science , silt , groundwater , reuse , lime , soil quality , environmental engineering , waste management , soil water , geology , engineering , soil science , geotechnical engineering , paleontology
Upland placement of dredge sediments has the potential to provide beneficial reuse of suitable sediments for agricultural uses or urban soil reconstruction. However, the use of many dredge materials is limited by contaminants, and most established screening protocols focus on limiting major contaminants such as heavy metals and polycyclic aromatic hydrocarbons and generally ignore fundamental agronomic parameters. Since 2001, we have placed over 450,000 m 3 of Potomac River fresh water dredge materials and 250,000 m 3 of saline materials from various locations into monitored confined upland facilities in Charles City, VA, and documented their conversion to agricultural uses. Groundwater and soil quality monitoring has indicated no adverse effects from material placement and outstanding agricultural productivity for the freshwater materials. Once placed, saline materials rapidly leach and ripen with quick declines in pH, electrical conductivity, and sodicity, but potentials for local groundwater impacts must be considered. Our experience to date indicates that the most important primary screening parameter is acid‐base accounting (potential acidity or lime demand), which should become a mandatory analytical requirement. Our second level of acceptance screening is based on a combination of federal and state residual waste and soil screening standards and basic agronomic principles. High silt+clay and total organic C may also limit rapid use of many dredge materials due to extended dewatering times and physical limitations. This dredge material screening system separates potential upland placement candidates into three soil quality management categories (unsuitable, suitable, and clean fill) with differing monitoring requirements. Similar use of these sediments in urban soil reconstruction is also recommended. Core Ideas Over 750,000 m 3 of freshwater and saline dredge materials converted to productive soils. New screening protocols developed integrating dredge properties with agronomic considerations. Transformations of saline materials documented along with risks to local soil and water quality. The importance of recognizing and treating potentially acid‐forming materials is emphasized. Potential for use of dredge materials as topsoil substitutes discussed.