Confidential
DSI provides ongoing modeling and consulting support as the Feasibility Study is completed.
Newtown Creek is a tidal arm of the New York-New Jersey Harbor Estuary and a tributary of the East River, including five tributaries along its 3.8-mile reach. The freshwater flow to Newtown Creek derives entirely from groundwater, stormwater, and wastewater discharges. As a result of the many industrial operations along the creek over the past 150 years, the water quality has degraded. It contains contaminated substances such as PCBs, PAHs, and heavy metals. The EPA listed Newtown Creek as a Superfund site in 2010.
The Study Area is subject to an Administrative Settlement Agreement and Order of Consent (AOC) formed between EPA and six Respondents, including the City of New York (NYC) and a group of five private parties known as the Newtown Creek Group (NCG). The AOC requires the Respondents to perform a Remedial Investigation (RI) and Feasibility Study (FS) for the site under EPA oversight. The consultant for the NCG, AnchorQEA, is currently completing the multi-year, phased RI/FS.
Our client has tasked DSI to review the AnchorQEA models and reports and support attorneys in developing lines of evidence for allocation briefings. DSI has regularly met with the EPA and the NCG over the past ten years. To better understand the system, DSI has also developed its own Newtown Creek Hydrodynamic, Sediment Transport, and Chemical Fate and Transport model using the same input initial conditions and model parameters as the AQEA model. As sediment transport is a fundamental aspect of this study, DSI has significantly enhanced the propeller wash component. The enhancements involved developing our own state-of-the-art propeller wash simulation module in EFDC+. This module allows data analysis and visualization of AIS data and automated integration of ship tracks into the EFDC+ sediment simulation.
DSI supported our client by developing models to assist in evaluating remedial alternatives during the FS phase of the RI/FS. The propeller wash module allows DSI to process AIS data and simulate actual ship passages along the channel. DSI used this information at various transects to investigate the history of multiple ships and their significant impact on the AQEA model result. DSI calculated gross erosion flux by each sediment class to identify the propwash impact differences between the two models. This allowed DSI to provide detailed reviews of the AQEA simulation and guide the evaluation of the model.
DSI continues to provide modeling and consulting support to our client as the Feasibility Study is completed.