3D Hydrodynamic Modeling of the

3D Hydrodynamic Modeling of the Lower Passaic River, New Jersey

Nicholas B Kim (1), Honghai Li, James Fitzpatrick

HydroQual, Inc., 1200 MacArthur Blvd., Mahwah, NJ 07430 (1) nkim@hydroqual.com, 201-529-5151

201-529-5728

A high resolution three-dimensional hydrodynamic model was developed to address the transport of highly contaminated sediment in the Lower Passaic River(LPR) in New Jersey. The Lower Passaic River, which encompasses about 17 miles of tidally influenced waters from the Dundee Dam to its confluence with Newark Bay and the Hackensack River, was a center of industrial and urban development in the 19^th and 20^th century, and as a result accumulated an array of toxic contaminants in its sediments. In 1984, USEPA added this section of the river to the National Priority List and it became eligible for cleanup under superfund funding. Modeling the hydrodynamics of the Passaic-Hackensack-Newark Bay system is essential to predict the movement of and concentrations of various chemicals of concern within the study area under different management and/or remediation scenarios (e.g. dredging, monitored natural attenuation, capping, etc.)

A careful design yielded a high-resolution model grid representing complex bathymetric features within the river system and connecting water bodies, which contain an extensive network of shipping channels maintained by the USACE. The high resolution LPR model was embedded within a coarser resolution model, which addresses regional hydrodynamic conditions. Comprehensive model forcing data include: tidal elevations, temperature and salinity at open boundaries, freshwater inflows from riverine and point and non-point sources, and meteorological data including wind and surface heat flux parameters.

The model was calibrated against extensive data sets collected in 1995-96, and 2004. Model computations were compared against observed tidal water elevations, current velocities, and time-series of temperature and salinity mooring data. Extensive graphical and statistical presentation of model-data comparisons were performed as model skill assessments. The results indicate that the detailed hydrodynamic processes within the LPR domain as well as its interactions with other regions of the New York Harbor System are well reproduced.