Sediment Characterization and Disposal
Accumulated sediments located in waterways require comprehensive characterization prior to removal to facilitate the selection of suitable disposal sites and minimize impacts to project schedule and budget. Sediments often contain a variety of environmental contaminants above regulated concentrations. The deposition process can concentrate heavy contaminants such as metals and create an anerobic environment that can reduce the potential for degradation of volatile organic compounds (VOCs) such as petroleum hydrocarbons. Additionally, pesticides, PCBs, and PFAS compounds are known to persist in the environment and can accumulate in sediment.
Most waterways receive sediment from point source and non-point source discharges so review of the industries and facilities in the associated drainage basin can be beneficial for determining chemical analytical parameters. Agricultural sources are common contributors to the total sediment load of a waterway and excess nutrients are another significant source of contamination.
Along with chemical contaminants geotechnical factors often make sediments undesirable as fill material and limit opportunities for beneficial reuse. Therefore, a comprehensive characterization of the chemical and physical properties of the sediment, including volumes, prior to the final scoping of the project is critical.