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Marcia Greenblatt, Ph.D., P.E.
Technical Director

Marcia Greenblatt, Ph.D., P.E.

Technical Director

Dr. Marcia Greenblatt is a water resources engineer with 22 years of specialized experience in hydrodynamic, water quality, and sediment investigations. She has extensive involvement in CERCLA remedial investigations and feasibility studies (RI/FSs) at large sediment sites. Her responsibilities have included management of a major feasibility study and design of sediment, water column, and bathymetric data collection programs and field sampling plans. In addition, she has integrated data analyses within a geographic information system (GIS) to support site conceptualization, characterize and evaluate fate and transport processes, identify data gaps, parameterize and apply numerical models,...

Dr. Marcia Greenblatt is a water resources engineer with 22 years of specialized experience in hydrodynamic, water quality, and sediment investigations. She has extensive involvement in CERCLA remedial investigations and feasibility studies (RI/FSs) at large sediment sites. Her responsibilities have included management of a major feasibility study and design of sediment, water column, and bathymetric data collection programs and field sampling plans. In addition, she has integrated data analyses within a geographic information system (GIS) to support site conceptualization, characterize and evaluate fate and transport processes, identify data gaps, parameterize and apply numerical models, and evaluate remedial alternatives. Dr. Greenblatt has designed and performed several modeling studies, applying both simple and complex numerical models, to predict hydrodynamic flows, sediment erosion, transport and deposition, chemical fate and transport, and water quality. She has performed numerous modeling studies for mixing zone evaluations to support NPDES renewals as well as operational evaluations, with several of these studies focused on thermal discharges. Dr. Greenblatt has served as both a testifying and consulting technical expert on water quality and sediment allocation matters.

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Sediment Investigation

Lower Passaic River RI/FS, New Jersey Project manager of the feasibility study, focused on evaluation of a source control interim remedy in the upper 9 miles of the 17-mile study area.  If implemented, the interim remedy would be part of an adaptive management program.  Participated in all aspects of this Lower Passaic River remediation project, including developing and managing sediment and water column field investigations; interpreting and analyzing data; and combining multiple lines of evidence (bathymetry, grain size, channel slope, and radiochemistry data) to support system understanding.  Works closely with the project coordinators and project consulting team supporting project strategy development and technical review of project documents.
Yosemite Slough Pre-Remedial Design Investigation, San Francisco, California Led a numerical modeling study to support an EPA non-time-critical removal action of lead- and PCB-contaminated sediments at the Yosemite Slough Superfund site.  A hydrodynamic and sediment transport model was developed to assess cap stability to support engineering design.  A field study was performed to collect site-specific data to set up and calibrate the models, and model predictions of bed shear stress and residual transport during tidal and storm conditions will be used in future design of capping and dredging remedy.
Big River Sediment Feasibility Study, Missouri Served as project manager for feasibility study of a 50-mile reach of a mining-impacted river.  The project included collecting sediment, soil, porewater, and tissue data to support a supplemental remedial investigation; developing a site conceptual model; updating the ecological risk assessment; performing a human health risk assessment; and identifying and evaluating remedial options.  Developed and directed field investigations to support development of site-specific preliminary remediation goals to support evaluation of potential remedial options.
Sparrows Point, Baltimore, Maryland Served as project manager of the investigation of potential offsite impacts of a steel mill to the surrounding harbor.  Provided strategic support during scope development negotiations with state and federal agencies.  Developed investigation approach, which included data collection, surface water modeling, and risk assessments.
Evaluation of Sediment Fate and Transport, Michigan Technical expert supporting litigation on allocation evaluation of contaminated river sediments.  Evaluated available data and previous court documents to develop a conceptual model of historical and ongoing sediment and contaminant transport at a Superfund site.
Engineering Evaluation and Cost Analysis (EE/CA) at a Former Chemical Manufacturing Facility, Portland, Oregon Supported the EE/CA for sediment remediation at the site in Portland Harbor, including evaluating potential recontamination of remedial alternatives and application of a cap model to support development of conceptual design parameters and cost estimates.
Confidential Site, Washington Provided senior planning and review for an analysis of the contributions of urban stormwater runoff to dioxin contamination in harbor sediments.  Supported development and review of an analytical, GIS-based model using the revised universal soil loss equation and measured dioxin concentrations in municipal and regional soils to estimate the potential dioxin load associated with runoff and the associated liability to the municipality.
Dredge Disposal Monitoring, Providence Harbor, Rhode Island Evaluated monitoring data collected during maintenance dredging.  Developed confined aquatic disposal (CAD) cells and dredging disposal into the CAD cells at the Rhode Island Sound Disposal Site, as directed by the Providence River and Harbor Maintenance Dredging Project Water Quality Certification.  Compared dredge material plume modeling results performed to support the environmental impact statement with monitoring results and recommended potential improvements for development of future dredged material monitoring plans.

Thermal Modeling

Thermal Discharge Study, Kennedy Center for Performing Arts, Washington, DC Designed a field program to characterize the thermal discharge into the Potomac River.  The study was performed as part of NPDES compliance, and required that the Kennedy Center provide a temporal and spatial characterization of the thermal plume.
Thermal Discharge Study, Ohio Designed a field program and modeling study as part of a thermal discharge study evaluating the refinery discharge plume to support an NPDES permit renewal.  The field program includes long-term deployment of moorings and several boat-based surveys to delineate the thermal plume under a range of seasonal conditions.  The modeling program includes both CORMIX (for nearfield analysis) and EFDC (farfield analysis) to predict the extent of the thermal plume under existing conditions not observed during the field study as well as future loading conditions.  Developed the work plan, which included negotiation with and approval from Ohio EPA.
Thermal Discharge Analysis, Michigan Evaluated the potential impact of increased thermal blowdown from the addition of a new unit at an existing nuclear power facility.  Served as senior reviewer of the CORMIX model, which was used to predict the thermal mixing zone under typical and extreme monthly conditions, as well as rare events.  The thermal discharge analysis also included data collection and review and statistical analysis of flow conditions.  Presented the results on two occasions to the Nuclear Regulatory Commission.
Thermal Study of a Cooling Reservoir, Texas Provided senior modeling oversight for the development of a 3-dimensional hydrodynamic and thermal model.  Set up and applied the model to evaluate the potential impact of increased thermal load and reservoir reconfiguration on reservoir water temperatures.  Project included characterization of reservoir temperatures and stratification, and calibration of the EFDC model to the observed temperatures.  Ran the model to simulate a potential worst-case meteorological and loading condition to characterize temperatures across the reservoir.
Three-Dimensional Hydrodynamic and Thermal Modeling Study, Southeastern United States Served as project manager and senior model reviewer, overseeing the development and application of the EFDC numerical model, which was used to evaluate the effect of moving a thermal discharge location on cooling water intake temperatures in a tidal estuary.  The proposed channel bypass would move the heated discharge approximately 2 miles closer to the intake location.  The model was developed as a submodel to a regional model and calibrated to available water surface, salinity, and temperature measurements.  Several months of plant operation were simulated, and predicted intake temperatures with and without the proposed bypass were compared to support the decision-making process surrounding the construction of the bypass channel.
Temperature TMDL Study, Vermont Developed a numerical model (SNTEMP) to simulate water temperature in a river in support of the TMDL process.  Field data were used to calibrate and validate the model.  The model was applied to assess the effects of alternative management scenarios on instream water temperature.  Model results were compared to the requirements of native and/or desired species to determine the optimum alternatives for adequate habitat.

Expert Testimony

Thermal Discharge Evaluation, Vermont Provided expert testimony in oral deposition, written testimony, and public hearings on the potential impact of thermal discharge from a nuclear power plant to receiving waters.  Evaluated flow and temperature data and a hydrodynamic and thermal transport model to assess completeness of impact characterization.
Thermal Discharge Permit Evaluation and Litigation Support, Confidential Site Evaluated existing NPDES thermal discharge permit and supporting modeling and data to assess validity and achievement of permit limits.  Wrote expert opinion report.
Florida v. Georgia No. 142, Original Testified as an expert witness in the U.S. Supreme Court in an interstate water rights case.  Performed hydrodynamic modeling to evaluate water quality impacts due to upstream water use.


Three-Dimensional Hydrodynamic and Sediment Transport Modeling Study, Gulf of Mexico Set up and applied the EPA-supported EFDC model to evaluate potential water quality and benthic habitat impacts associated with proposed construction of a pipeline from Tampa Bay through the Gulf of Mexico.  Applied the model to predict tidally varying currents and sediment transport and deposition potentially resulting from pipeline construction activities.  Modeling activities included application of the U.S. Army Corps of Engineers ADDAMS models DREDGE and STFATE to estimate sediment resuspension rates from dredging and sidecasting operations, and mapping model-predicted suspended sediment concentrations and sediment deposition extents and depths over sensitive habitat areas.
Hurricane Protection Office, New Orleans, Louisiana To support the design-build of a 9,000-ft hurricane barrier in coastal Louisiana, developed a numerical model to evaluate channel velocities during construction and operation of the barrier sector gates.  Designed and managed the field program implemented to characterize the flows and circulation patterns in the study area.  An RMA-2 model was set up, calibrated, and validated to a large set of available field data throughout the model domain.  The calibrated model was applied to predict velocities for a set of design scenarios, and the model results were used to support the design team in construction and operations planning.


Discharge Permit Renewal Evaluation, American Samoa Provided consulting expertise and strategic direction to support renewal of a NPDES permit to discharge nutrients into a harbor.  Work included review of existing data and mixing zone modeling, development of CORMIX initial mixing model and DELFT3D far-field numerical model, and submittal of an expert report to support comments on draft permit.
Anti-Degradation Evaluation, Ohio Evaluated the impact of cessation of a groundwater pump and treat system on downstream water quality.  Applied state guidance to model potential future water quality for evaluation of anti-degradation potential.
Thermal Discharge Permit Evaluation, Confidential Site Evaluated existing NPDES thermal discharge permit and supporting modeling and data to assess validity and achievement of permit limits.  Wrote expert opinion report.
Mixing Zone Analysis, Gilbert Generating Station, New Jersey Applied CORMIX expert mixing zone model to determine the extent of the mixing zone induced by a cooling water discharge.  Compared results with applicable water quality standards.
Water Discharge Permitting, Wythe, North Carolina Modeled the mixing zone of a cooling tower discharge into an adjacent river for several constituents of interest.  Evaluated alternative diffuser designs to determine the best design and location for maximum mixing.
Water Supply and Discharge Design and Permitting, Rensselaer, New York Evaluated siting intake and discharge locations to avoid recirculation on the tidally reversing river for a proposed newsprint facility on the Hudson River.  The potential to entrain fish larvae at the intake was evaluated on a seasonal basis for the vulnerable life stages of each species.  The mixing zone of the effluent was evaluated for various times during the tidal cycle under a range of freshwater inflow conditions.  The optimal diffuser design was developed to meet the mixing requirements and the physical constraints within the river (including rapidly changing bathymetry and the proximity to a shipping channel).


Disposal Area Monitoring System (DAMOS), New England Served as program manager for the DAMOS program for monitoring of disposed sediment and benthic habitat recovery at dredged material disposal sites in coastal New England and New York.  Budgeted tasks, planned resources and surveys, and coordinated subcontractors.  Oversaw monitoring cruises that typically included bathymetric, side-scan, and sediment-profile imaging (SPI) surveys after the disposal season.  Supported the development of bathymetric maps and depth-difference maps, interpretation of SPI results, and comparison of disposal area sediment data with reference and historical data.  Wrote and reviewed technical reports included as DAMOS contributions and distributed to the public.  Coordinated the 10th and 11th DAMOS symposia, where recent DAMOS work and new technological advances were presented to government representatives (state and federal) as well as the interested public.
Physical Oceanographic Evaluation, Long Island Sound, New York As part of a major EPA-required environmental impact study to assess potential impacts associated with dredged material disposal and evaluate alternative candidate disposal sites in Long Island Sound, performed extensive oceanographic data analysis, including time series analysis and spectral analysis of water velocity and wave data, and developed a graphical presentation of all historical and recent data.  Specific tasks included an intensive review of historical physical oceanographic data, creation and distribution of a GIS-based database of all physical oceanographic data on Long Island Sound, collaboration and meetings with the research community in the sound to reach consensus on required future hydrodynamic data collection, and selection of optimal disposal site locations in terms of hydrodynamic and sediment transport objectives.

Water Quality Modeling

Barr Lake and Milton Reservoir Nutrient Total Maximum Daily Load (TMDL) Water Quality Model, Colorado Served as project manager for the expansion (including new input data) and recalibration of a water quality model to support assessment of TMDL alternatives for the Barr Lake and Milton Reservoir Watershed Association Technical Committee.  The linked watershed/‌in‑lake model simulated flows and nutrients in a complex system with an extensive canal system, numerous irrigation inputs and withdrawals, and two water supply reservoirs.  The EPA models SWAT and WASP were applied to ultimately predict present and potential future in-lake nutrient systems in a severely eutrophic system.
Sedimentation and Water Quality Modeling Study, Alaska Led a study to evaluate the potential sedimentation and turbidity impacts due to proposed construction of a trans-Alaska liquefied natural gas pipeline.  Developed a 3-dimensional hydrodynamic and sediment transport model using Delft-3D to predict water column turbidity concentrations and sedimentation based on proposed construction activities.  Models were set up in a tidal bay and in multiple freshwater streams to characterize the range of potential impact.  Submitted modeling reports as part of the Federal Energy Regulatory Commission application to support the environmental report.
Industrial Effluent Modeling in Tidal Estuary, Nova Scotia, Canada Modeled nearfield and farfield dilution and mixing of an industrial effluent discharge into a tidal estuary to support the identification of alternate locations for relocating an existing outfall.  Used the 3-dimensional hydrodynamic and water quality model HEM3D to simulate a conservative tracer and predict the extent of the visible plume.  A number of locations and discharge scenarios (continuous, hold-and-release) were investigated.  Calibrated the farfield model by using measurements taken during a synoptic field survey specially designed to support the modeling task.  Conducted nearfield mixing modeling to evaluate alternative diffuser designs.
Nonpoint Source Modeling for Nutrient TMDL Study, Massachusetts Modeled hydrology, water quality, and biology in a eutrophic river system in support of the TMDL process.  Project included several rounds of field data collection and analysis, model selection, setup, and development.  Set up an application of the HSPF watershed and instream numerical model to simulate point and nonpoint source flow and nutrient loads into the river, as well as instream nutrient and biomass interactions.  Set up the model based on GIS data, and calibrated and validated the model using several sets of field data.  Once calibrated, applied the model to assess several alternative management scenarios.
Oil Spill Modeling, Brazil Used available bathymetry and shoreline data to set up and apply a hydrodynamic and oil spill model to assess the impact of a potential oil spill in support of a permit application.  The dynamic model was calibrated to measured current and water surface elevation data collected for the study.  The predicted flow fields were imported into a particle tracking oil spill model.  The oil spill model was applied for several dominant wind conditions and several types (varying in location, duration, and volume) of oil spills.  The areal extent and location of the spill were tracked for several days.  The extent of coastline potentially impacted and the time until impact were assessed for each modeled scenario.

Sediment Transport Modeling

Dredge Disposal Evaluation, Savannah Harbor, Georgia Applied the ADDAMS STFATE model to evaluate the fate and transport of disposed dredge material in Savannah Harbor.  Used field data to set up the model.  Conducted model simulations to estimate sediment transport and water column concentration.  Model results were interpreted to determine whether relevant water quality standards were achieved within the disposal area.

Water Quality Sampling

Water Quality and Fish Tissue Field Study, Confidential Client Designed and implemented a field program to evaluate recent water quality and tissue concentrations for emerging contaminants.  The program was designed to characterize fluxes, identify potential upland sources, and compare to previous studies.  Program was designed and implemented in an expedited timeframe to support ongoing negotiations.