Newark Bay Study - Passaic River Public Digital Library

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1-14 Bottom sediments were also characterized in detail as part of this early sampling program (~100 surface sediment samples). The results indicated that the surface sediments of the northern region of Newark Bay are primarily composed of particulate material having a grain size that is representative of silt. The lower Hackensack River sediments have a somewhat coarser texture than the lower Passaic River and northern Newark Bay sediments. The sediment composition becomes coarser in texture in the direction of South Newark Bay, a trend that likely reflects the more intense long-term dredging activity and relatively high current speeds in that area, particularly in the Kill van Kull. Surficial bottom sediment concentrations were also measured, with a focus on levels of total organic carbon (TOC) and 8 metals: Hg, Cd, Pb, As, Cu, Zn, Cr and Ni. The concentrations of these constituents will be discussed in a later section of this report. Suszkowski used the 1976 monthly monitoring data, supplemented by additional sources of information on velocity profiles at the 4 Newark Bay boundaries, to develop a detailed inorganic solids balance for the system. The approach was to evaluate the surface and bottom layer flows at each of the four points of entry to the Bay (discussed above), and to then assign the observed average TSS concentration to each of these. (It is of interest to note that the boundary at the Passaic River had a distinctly different TSS profile than the other locations, with the surface layer TSS being consistently higher than the bottom layer TSS concentration.) The product of the flow and TSS concentration in the surface and bottom layers yields an estimate of the mass flux rate, and the difference between the surface and bottom layer fluxes represents an estimate of the net flux across each Newark Bay boundary. Additional internal sources of solids, including TSS inputs from wastewater treatment plants, urban runoff and phytoplankton production were also quantified. Finally, a net solids balance for the entire Bay was obtained by evaluating the sum of all of these inputs. The results of Suszkowski’s solids balance analysis are summarized on Figure 1-3. It is evident from these results that the Passaic River, Kill van Kull and Arthur Kill were all net sources of TSS to Newark Bay, while the Hackensack River was a net sink of solids at the time of this investigation. This latter finding was recently confirmed by simulations performed with the Newark Bay model by Pence (2004). The simulations involved the initialization of a particle concentration of 1 mg/L in the Passaic River, on a monthly basis, and then tracking the movement over these particles over the course of an annual cycle. The particles tended to move from the Passaic River, into Newark Bay, and then left Newark Bay by transport into the Hackensack River, or by transport out of the system in the surface layers of the Arthur Kill and Kill van Kull. The difference in transport regimes for the Hackensack and Passaic Rivers is partly explained by the relatively low freshwater flow in the Hackensack River, as this facilitates the upstream transport of solids from the Bay. Additionally, during high flow events there is relatively little upstream storage in the Passaic River, so peak flow rates propagate through the system with relatively little attenuation. This differs from the situation in the Hackensack River, where upstream reservoir storage will absorb many of
the peaks in flow, thereby limiting the potential for flushing of solids from the Hackensack River to the Bay. Mass Flux (10 6 kg/year) 600 400 200 0 -200 -400 42 Passaic River Upstream Internal Downstream 210 -23 18 99 Hackensack R -28 -127 Wastewater 6 6 9 9 9 9 0 Urban Runoff 0 Input Output Net Phytoplankton 0 81 Arthur Kill -49 - - - - - - - - - - - - - - Sources - - - - - - - - - - - - - 32 Kill Van Kull -144 66 455 Total -343 Figure 1-3. TSS Balance for Newark Bay (Adapted from Suszkowski, 1978). 112 1-15 Another significant finding by Suszkowski was that the Kill van Kull was the major contributor of suspended sediment to the Bay, contributing 46% of the total input of solids to the Bay. This may be compared to the contribution from the major freshwater tributary to Newark Bay, the Passaic River, which only contributes 9% of the total input of solids. This demonstrates a need to incorporate within the overall modeling framework (as well as a properly designed field program) that includes the Arthur Kill and the Kill van Kull and their connection to New York/New Jersey Harbor in order to develop a proper sediment transport model of Newark Bay and the lower Passaic River. Overall, estimates of these solids fluxes lead to a Newark Bay average inorganic sediment accumulation rate of 116.7 x 10 3 MT/year. Suszkowski used long-term dredging records and isopach (lines showing equal changes in depth) calculations to confirm that this was a reasonable solids flux estimate. Assuming a typical bed solids concentration of 400 g/L and a surface area of the Bay of 14.2x10 6 m 2 (Suszkowski, 1978) this volumetric accumulation rate for inorganic solids is equivalent to a net sedimentation rate of 1.97 cm/year as a Bay-wide average (exclusive of dredging). Use of this Bay-wide average sedimentation rate in conjunction with an estimate in the range of nil to 0.35 cm/yr (Suszkowski, 1978; NOAA, 1984) for non-navigation channel areas of Newark Bay (associated with ~74% of Newark Bay), results in an estimate for the net sedimentation rate in the navigation channels in the range of 6.6 – 7.6 cm/yr. Overall, the sedimentation rates predicted on
Page 3 and 4: Newark Bay Study Final Modeling Wor
Page 5 and 6: FIGURES Figure Page Figure 1-1. New
Page 7 and 8: SECTION 1 1 INTRODUCTION 1.1 OVERVI
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Page 11 and 12: • Establish the magnitudes and re
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Page 19: 1.4.2.1 A Macro-Scale Solids Balanc
Page 23 and 24: Figure 1-4. Bathymetry and Sediment
Page 25 and 26: Figure 1-5. Sampling locations with
Page 27 and 28: Table 1-2. Extent of historical dat
Page 29 and 30: 1-23 an exhaustive data analysis ha
Page 31 and 32: PCBs (ng/g) PCBs (ng/g) PCBs (ng/g)
Page 33 and 34: depositional/erosional patterns in
Page 35 and 36: TCDD (ng/g) TCDD (ng/g) TCDD (ng/g)
Page 37 and 38: TCDD (ng/g) 0.2 0.16 0.12 0.08 0.04
Page 39 and 40: 1-33 locations indicate that OCDD i
Page 41 and 42: tPAHs (ng/g) tPAHs (ng/g) tPAHs (ng
Page 43 and 44: 1-37 and RM6, there seems to be an
Page 45 and 46: Depth (ft) Depth (ft) 0 2 4 6 8 10
Page 47 and 48: Chromium (ng/g) Chromium (ng/g) Chr
Page 49 and 50: 1-43 westerly section of the Kill v
Page 51 and 52: Arsenic (ng/g) Arsenic (ng/g) Arsen
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