A Model for the Evaluation and Management of Contaminants of ...

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(TMDLs), as required by agreements between the U.S. Environmental Protection Agency (EPA) and the states of New York and New Jersey for substances of concern, in all water, sediment and/or biota of the NY/NJ Harbor. • Development of management tools to predict concentrations of other substances determined by the Toxics Workgroup of HEP to be of concern in water, sediment, and biota; • Development of a management tool to predict effects of changes in Harbor bathymetry on the distribution of the contaminants of concern; and • Development of a management tool to facilitate potential Natural Resource Damage Claims. It is the consensus of CARP participants that mathematical modeling tools are needed to help the region address some or all of these goals. Such models provide a means for integrating available ambient concentration and loading data in a mass balance framework so that dominant fate and transport processes can be identified. Moreover, these models may provide the predictive capability that managers and scientists need to assess the consequences of various remedial actions (e.g., additional source trackdown efforts, remediation of contaminated sediments, TMDLs/WLAs/LAs, clean-up of contaminated sites) and to predict the time frames required for reductions in contaminant levels in Harbor waters, sediments and biota. Accordingly, this RFP provides generalized tasks and specifications for the development and application of such models. II. Modeling Questions The specific questions that need to be addressed through modeling are as follows: What is the relative importance of specific loadings of contaminants to the quality of dredged material today? (What current pollutant sources/ loadings can be linked to contamination problems (i.e., criteria violations) at dredging locations in New York Harbor and what proportion of the problem is attributed to each source?) How will the quality of newly deposited sediments at future dredging sites change if no contaminant reduction actions are taken? How will the sediments be affected if specific contaminated loadings are reduced or eliminated? A. How long will it take for improvement in newly deposited sediment quality after contaminant reductions are made? B. What actions can produce the greatest benefits (both in time and areal extent)? C. What actions are needed to reduce the amount of contaminated dredged material from about 70% in year 2000 to less than 15% by 2040? (These are the targets set in the Army Corps of Engineers’ (COE) Dredged Material Management Plan for the harbor.) 3
Testing of harbor dredged materials proposed for open water disposal has revealed that many sediments contain contaminants that are bioaccumulated by organisms (i.e., clams, Macoma sp., and worms, Nereis sp.). In addition, many sediments have been found to be acutely toxic to amphipods in laboratory tests. The primary contaminants of concern are PCBs, dioxin, polycyclic aromatic hydrocarbons (PAHs), DDT (and its metabolites), chlordane, cadmium and mercury. As CARP has progressed, other contaminants have been added to the list of contaminants of concern. The current list of analytes to be measured by CARP is contained in Table 1. Research and development of a contaminant fate and transport model to assess the effects of various organic contaminant loads on the ecosystem (including sediments) was initiated during 1995. This effort, undertaken by researchers at Manhattan College, was sponsored by the Hudson River Foundation (HRF) with co-funding from the Port Authority of New York and New Jersey (Port Authority) and EPA. The resulting large-space-scale, seasonal-time-scale model for contaminant fate and bioaccumulation is relevant to dredged material management since it can be used to address the above questions by assessing the effects of contaminant loads on dredged material endpoints such as the bioaccumulation of PCBs, dioxin and PAHs. Currently, this and other similar models have limited utility to dredged material management primarily because ambient concentration and loading data for the contaminants of concern do not exist. These ambient data are needed to validate and verify the model, while the loading data are essential inputs to the model. This shortcoming is being addressed by the comprehensive monitoring programs being undertaken by both the New York Department of Environmental Conservation and the New Jersey Department of Environmental Protection with support from the Port Authority. Another limitation of the Manhattan College model stems from its coarse segmentation. Finer spatial scaling is needed to provide more information about effects of particular dischargers and specific dredging sites. Future models will also have to include other problematic chemicals such as DDT (and its metabolites), mercury, cadmium and chlordane. And eventually they will need to consider toxicity as well. III. General Modeling Approach To best assist the Port Authority and other dredged material managers, the CARP Modeling Work Group has proposed that a tiered process be undertaken for future modeling. The first tier involves selecting, refining and applying existing large-space-scale, seasonal-time-scale model(s) for contaminant fate and bioaccumulation. The model(s) must be an advancement over previously constructed models to incorporate: (1) all of the primary contaminants of concern (i.e., PCBs, dioxin, PAHs, DDT, mercury, cadmium and chlordane); (2) appropriate spatial coverage in New York Harbor to evaluate dredging sites and the influence of “hot spots”; and (3) appropriate water, suspended sediment and organic carbon kinetics. The model(s) will then be run using newly collected monitoring 4
Page 1 and 2: A Model for the Evaluation and Mana
Page 3 and 4: NY/NJ Harbor Estuary Program Contam
Page 5 and 6: Budget Breakdown by Task CARP Model
Page 7: I. Introduction A consortium of sta
Page 11 and 12: Pesticides Hexachlorobenzene alpha
Page 13 and 14: Table 2: Sediment Physical Paramete
Page 15 and 16: Table 4a. Summary of New Jersey amb
Page 17 and 18: scientifically reliable results. Ta
Page 19 and 20: Task 1-6: Conduct model sensitivity
Page 21 and 22: athymetry, variable flows, fixed fl
Page 23 and 24: Both models will use loadings infor
Page 25 and 26: Twenty Copies of the Proposal shoul
Page 27 and 28: Figure 1: Distributions of sediment
Page 29: Figure 3: Distributions of sediment

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