Tools for Assessing the Fate of Dredged Material
Tools for Assessing the Fate of Dredged Material Speaker: Joseph Gailani Research Hydraulic Engineer Research Group: Tahirih Lackey, Earl Hayter, Ray Chapman, SungChan Kim, Paul Schroeder, and Jarrell Smith Engineer Research and Development Center October 25, 2012
US Army Corps of Engineers
BUILDING STRONG®
Motivation Data related to dredged material fate for mgmt purposes are limited Models and tools permit user to extrapolate to conditions for which data are not available Provide framework within which to quantify fate, assess options and compare alternatives
BUILDING STRONG®
Motivation Increasingly complex issues related to dredged material fate ► ► ► ► ► ►
Regulatory compliance Environmental Resources/Risk Assessment Site/lifecycle management Dredged material as a resource Engineering with Nature Regional or multiple project management
Models are one of several tools used to address these issues (line/lines of evidence) Models require improved process descriptions to address these issues Users need a suite of modeling tools ► ►
Various levels of model (screening to detailed) Address specific processes
Models and databases must be interconnected to provide efficient use and maximize benefit
BUILDING STRONG®
Objective Develop/maintain a suite of tools, models and databases to address Corps issues related to dredged material fate and management ► Develop needed process descriptions for improved accuracy and range of applicability ► Increased interaction with other Corps models, databases, and tools ► Tiered models to address appropriate level of accuracy/user needs ► Demonstrate applicability Decrease time required for model setup, application and interpretation through efficient user interfaces BUILDING STRONG®
Transport Model Improvements Our understanding of sediment processes is improving thanks to improved technologies Remote sensing Large data set storage Ability for field measurement at fine resolution Demonstrate applicability Improved process descriptions incorporated into models Bottom boundary layer processes Model parameterization Long-term/large-scale change All scales of models benefit from these new data and descriptions BUILDING STRONG®
STFATE Short-Term Fate of Dredged Material Provide deposition pattern and resuspension from placement Manage placement sites Regulatory Compliance (water column concentration) ► Section 103 of the MPRSA ► Section 404 (B)(1) of the Clean Water Act STFATE includes descent, dynamic collapse, Evaluate environmental bottom transport, and stripping phases resource issues
BUILDING STRONG®
MDFATE/ MPFATE Multiple Disposal Fate of Dredged Material Multiple Placement Fate of Dredged Material • • •
MPFATE includes multiple STFATE simulations, mound building, erosion, consolidation, and avalanching
Cumulative resuspension from placement operations (multiple STFATE clouds) Generate mound configuration from placement operations Address Issues related to: – Regulatory Compliance – Minimizing hazards – Optimizing operations, long-term mgmt – Operational efficiency – Design capping operations
• Tool to optimize placement locations BUILDING STRONG®
STFATE/MPFATE Improvements
Complex hydrodynamics Complex bathymetries Improved settling algorithms Continuous or discrete discharge Source term to far field fate models
Multiple plumes for water quality assessment Complex bathymetry Optimization routines to maximize capacity BUILDING STRONG®
GTRAN Sediment Pathway Model
Optimize Nearshore Placement Location to maximize benefit to Tybee Island and minimize rehandling BUILDING STRONG®
PTM Particle Tracking Model •
• • • •
•
A far field dredged material transport model specifically designed to simulate multiple scenarios Quantify DM transport and fate over large domains to assess impacts/risks PTM reduces computational intensity by only modeling transport of DM DM interactions with sediment bed treated through active layer dynamics Issues Addressed: – Far-field transport, deposition, and resuspension – Time-varying sediment and constituent concentration – Dose estimates at receptors Powerful post-processing tools – convert particle distribution to TSS, sedimentation, etc
Quantify erosion, deposition, and dose over large domain. Map sediment and constituent pathways, can use FATE model output as DM sources BUILDING STRONG®
PTM Improvements
Computational efficiency for year+ simulations Improved boundary conditions New settling algorithms with parameterization Fish larvae behavior Modeling of silt curtain effects and other control systems
More complex bottom boundary conditions Improved wetting/drying transport algorithms Improved bottom boundary layer descriptions developed by recent laboratory and field experiments BUILDING STRONG®
LTFATE Long Term Fate of Dredged Material
Waves
Surge
TSS/Transport
Current Erosion/Deposition
LTFATE: Wave/current sediment erosion, transport, and deposition. Mound morphology, mixed sediment processes, 3-D hydrodynamics, contaminant transport
Post-Placement migration and dispersion of dredged material mounds Quantify ► Hydrodynamic-driven mound morphology change ► Local deposition patterns and thickness ► Mass exiting local domain Issues addressed: ► Dispersive/non-dispersive site ► Direction/fate of material removed from ODMDS ► Long-term management of dredged material mounds ► Regulatory compliance and resource issues ► Dredged material mound as resource for sediment nourishment ► Sediment rehandling BUILDING STRONG®
LTFATE Improvements
3-D Large domain hydrodynamics, α- or z-grid Wave/current interactions 3-D, multiple grain size sediment bed and transport Floc/aggregate transport Parameterize transport processes using site-specific data Wetting/drying
Multi-Block capabilities for computational efficiency Improved bottom boundary layer descriptions developed from recent laboratory and field experiments Fluid mud transport Improved nearshore/shallow water processes BUILDING STRONG®
US Army Corps of Engineers
BUILDING STRONG®
Motivation Data related to dredged material fate for mgmt purposes are limited Models and tools permit user to extrapolate to conditions for which data are not available Provide framework within which to quantify fate, assess options and compare alternatives
BUILDING STRONG®
Motivation Increasingly complex issues related to dredged material fate ► ► ► ► ► ►
Regulatory compliance Environmental Resources/Risk Assessment Site/lifecycle management Dredged material as a resource Engineering with Nature Regional or multiple project management
Models are one of several tools used to address these issues (line/lines of evidence) Models require improved process descriptions to address these issues Users need a suite of modeling tools ► ►
Various levels of model (screening to detailed) Address specific processes
Models and databases must be interconnected to provide efficient use and maximize benefit
BUILDING STRONG®
Objective Develop/maintain a suite of tools, models and databases to address Corps issues related to dredged material fate and management ► Develop needed process descriptions for improved accuracy and range of applicability ► Increased interaction with other Corps models, databases, and tools ► Tiered models to address appropriate level of accuracy/user needs ► Demonstrate applicability Decrease time required for model setup, application and interpretation through efficient user interfaces BUILDING STRONG®
Transport Model Improvements Our understanding of sediment processes is improving thanks to improved technologies Remote sensing Large data set storage Ability for field measurement at fine resolution Demonstrate applicability Improved process descriptions incorporated into models Bottom boundary layer processes Model parameterization Long-term/large-scale change All scales of models benefit from these new data and descriptions BUILDING STRONG®
STFATE Short-Term Fate of Dredged Material Provide deposition pattern and resuspension from placement Manage placement sites Regulatory Compliance (water column concentration) ► Section 103 of the MPRSA ► Section 404 (B)(1) of the Clean Water Act STFATE includes descent, dynamic collapse, Evaluate environmental bottom transport, and stripping phases resource issues
BUILDING STRONG®
MDFATE/ MPFATE Multiple Disposal Fate of Dredged Material Multiple Placement Fate of Dredged Material • • •
MPFATE includes multiple STFATE simulations, mound building, erosion, consolidation, and avalanching
Cumulative resuspension from placement operations (multiple STFATE clouds) Generate mound configuration from placement operations Address Issues related to: – Regulatory Compliance – Minimizing hazards – Optimizing operations, long-term mgmt – Operational efficiency – Design capping operations
• Tool to optimize placement locations BUILDING STRONG®
STFATE/MPFATE Improvements
Complex hydrodynamics Complex bathymetries Improved settling algorithms Continuous or discrete discharge Source term to far field fate models
Multiple plumes for water quality assessment Complex bathymetry Optimization routines to maximize capacity BUILDING STRONG®
GTRAN Sediment Pathway Model
Optimize Nearshore Placement Location to maximize benefit to Tybee Island and minimize rehandling BUILDING STRONG®
PTM Particle Tracking Model •
• • • •
•
A far field dredged material transport model specifically designed to simulate multiple scenarios Quantify DM transport and fate over large domains to assess impacts/risks PTM reduces computational intensity by only modeling transport of DM DM interactions with sediment bed treated through active layer dynamics Issues Addressed: – Far-field transport, deposition, and resuspension – Time-varying sediment and constituent concentration – Dose estimates at receptors Powerful post-processing tools – convert particle distribution to TSS, sedimentation, etc
Quantify erosion, deposition, and dose over large domain. Map sediment and constituent pathways, can use FATE model output as DM sources BUILDING STRONG®
PTM Improvements
Computational efficiency for year+ simulations Improved boundary conditions New settling algorithms with parameterization Fish larvae behavior Modeling of silt curtain effects and other control systems
More complex bottom boundary conditions Improved wetting/drying transport algorithms Improved bottom boundary layer descriptions developed by recent laboratory and field experiments BUILDING STRONG®
LTFATE Long Term Fate of Dredged Material
Waves
Surge
TSS/Transport
Current Erosion/Deposition
LTFATE: Wave/current sediment erosion, transport, and deposition. Mound morphology, mixed sediment processes, 3-D hydrodynamics, contaminant transport
Post-Placement migration and dispersion of dredged material mounds Quantify ► Hydrodynamic-driven mound morphology change ► Local deposition patterns and thickness ► Mass exiting local domain Issues addressed: ► Dispersive/non-dispersive site ► Direction/fate of material removed from ODMDS ► Long-term management of dredged material mounds ► Regulatory compliance and resource issues ► Dredged material mound as resource for sediment nourishment ► Sediment rehandling BUILDING STRONG®
LTFATE Improvements
3-D Large domain hydrodynamics, α- or z-grid Wave/current interactions 3-D, multiple grain size sediment bed and transport Floc/aggregate transport Parameterize transport processes using site-specific data Wetting/drying
Multi-Block capabilities for computational efficiency Improved bottom boundary layer descriptions developed from recent laboratory and field experiments Fluid mud transport Improved nearshore/shallow water processes BUILDING STRONG®
