The Water Report Nov 2005 - Laserfiche WebLink

Home Browse Search

Issue #21 • Leaching The Water Report Surface Runoff Disposal ► CDF • Volatilization • Bioaccumulation Nearshore Nearshore Please refer to the following guidance manuals for additional Disposal CDF information on exposure pathways associated with these disposal .��JJii options. Subaqueous CAP Capping Figure 5. Dredging Generic Conceptual Site Model 2) EPA, 1998. Guidance for In -Situ Subaqueous Capping of Contaminated Sediment, EPA 905 -B96 -004. Sediments Potential Receptors Media of Exposure Secondary Tertiary Concern Pathway Media Pathway Media Site Model ► Dredging Resuspension Water Column Direct Contact g ► X� X 9 " X'' _J — Direct n Contact - __ f- _► 1 X) I - Settled Sediment _. Open Water Disposal - _. _ _..____ -- ` W Bioaccumulation 1 - - - -►� Tissue ' - -► X X i X' CSM Uses Potential Effects Dredging Evaluation Water Direct �i �X ! X Column Contact Sediment - - -- Disposal -------- ---- -------- - - - --- Transport Processes (Examples) - - - - -- Method The CSM provides a powerful tool for communicating ecological or human health (or other) issues among assessors, managers, and interested parties. The CSM identifies the complete and potentially complete exposure pathways and provides a template to conduct exposure pathway evaluations. It also provides a means to identify relevant receptors and potential response actions. The CSM is dynamic in the sense that, when available, additional data are used to refine and increase the accuracy of the CSM as necessary to reflect the current understanding of the project. The following are summary program objectives to consider in completing either a contaminated sediment investigation or a dredged material characterization project. Contaminated Sediment Projects The primary goal of assessing contaminated sediments is to determine the potential effects of the sediments in place. The site characterization process should allow for the accomplishment of the following goals: • Identify and quantify the contamination present in sediments • Understand the vertical and horizontal distribution of the contaminants in the sediments • Understand the physical, chemical, and biological processes affecting the fate and bioavailability of sediment contaminants at the site • Identify the complete human and ecological exposure pathways for the contamination • Identify current and potential human and ecological risks posed by the contaminants Dredging Projects The primary purpose of a dredging project is to remove material in order to maintain or create water depths to allow for safe passage or berthing of vessels. The evaluation of dredged material is to determine whether there will be unacceptable impacts either during the dredging process or at the disposal site. OF PRIMARY CONCERN ARE: • Whether the dredging process will affect or degrade the dredging site • Whether the disposal of dredged material will affect or degrade the disposal site, whether in -water or in some cases on land • Additionally, an evaluation of the sediment that will be exposed subsequent to dredging will be necessary 14 Copyright© 2005 Envirotech Publications; Reproduction without permission strictly prohibited. • Leaching Upland Upland Surface Runoff Disposal ► CDF • Volatilization • Bioaccumulation Nearshore Nearshore Please refer to the following guidance manuals for additional Disposal CDF information on exposure pathways associated with these disposal .��JJii options. Subaqueous CAP Capping 1) Corps, 2003. Upland Testing Manaul, ERD /EL TR -03 -1. 2) EPA, 1998. Guidance for In -Situ Subaqueous Capping of Contaminated Sediment, EPA 905 -B96 -004. The CSM provides a powerful tool for communicating ecological or human health (or other) issues among assessors, managers, and interested parties. The CSM identifies the complete and potentially complete exposure pathways and provides a template to conduct exposure pathway evaluations. It also provides a means to identify relevant receptors and potential response actions. The CSM is dynamic in the sense that, when available, additional data are used to refine and increase the accuracy of the CSM as necessary to reflect the current understanding of the project. The following are summary program objectives to consider in completing either a contaminated sediment investigation or a dredged material characterization project. Contaminated Sediment Projects The primary goal of assessing contaminated sediments is to determine the potential effects of the sediments in place. The site characterization process should allow for the accomplishment of the following goals: • Identify and quantify the contamination present in sediments • Understand the vertical and horizontal distribution of the contaminants in the sediments • Understand the physical, chemical, and biological processes affecting the fate and bioavailability of sediment contaminants at the site • Identify the complete human and ecological exposure pathways for the contamination • Identify current and potential human and ecological risks posed by the contaminants Dredging Projects The primary purpose of a dredging project is to remove material in order to maintain or create water depths to allow for safe passage or berthing of vessels. The evaluation of dredged material is to determine whether there will be unacceptable impacts either during the dredging process or at the disposal site. OF PRIMARY CONCERN ARE: • Whether the dredging process will affect or degrade the dredging site • Whether the disposal of dredged material will affect or degrade the disposal site, whether in -water or in some cases on land • Additionally, an evaluation of the sediment that will be exposed subsequent to dredging will be necessary 14 Copyright© 2005 Envirotech Publications; Reproduction without permission strictly prohibited.