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

data provided by both states to obtain preliminary answers to those questions listed above.
Such analyses will highlight dominant sources, sinks and transport pathways for Harbor
contaminants, and predict trends in terms of dredged material endpoints. Also, these
analyses may identify potential data deficiencies in the States’ ongoing monitoring plans.
The first-tier modeling results, anticipated in approximately two years, will be used to
develop priorities for contaminant reduction actions, to update the DMMP for the Port, and
to assist the region in planning for future port development.
The second tier of the modeling effort involves the development of explicit, finer-scale
models that couple hydrodynamics, water quality, and cohesive sediment transport. These
models can be used to guide and implement geographically specific reduction strategies
and dredged material management. Potential regulatory actions to reduce contamination
(e.g., TMDLs) will likely require assessments at very fine spatial and temporal scales,
including assessments of effects of individual discharges on the concentrations of
contaminants in various media at specific areas of the Harbor. Since water quality criteria
are at issue with regard to TMDLs, it may be necessary to assess these impacts on a
monthly, daily or even hourly basis. This is in contrast to current dredged material endpoints
(i.e., bioaccumulation and toxicity) which may be tracked at yearly intervals.
Dredged material managers have expressed the need to assess the accumulation of
contaminated sediments in specific navigation channels and berthing areas throughout
New York Harbor. They are particularly interested in understanding the relation between
erosion in certain shoal areas to deposition and contamination of nearby channel areas.
Developing the predictive understanding of these processes will require an explicit finescale
cohesive sediment transport model(s) to be constructed and a database of sitespecific
sediment characteristics to be compiled. This is a large and complicated
undertaking but can be combined with the fine-scale hydrodynamic and water quality model
development described above.
In summary, Tier-1 modeling will provide crucial planning information for the design of
regional contaminant reduction programs, and will inform both dredged material managers
and the public of the likely improvements to sediment, water and biota quality resulting from
reduction actions. It is proposed that this task be completed within a timeframe of eighteen
months to two years, depending on the availability of monitoring data. Tier-2 will provide
fine-scale modeling methods to support very specific contaminant reduction actions where
further detailed information is required. The fine-scale modeling effort may be completed
within three to four years.
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