Newark Bay Study - Passaic River Public Digital Library

Depth (ft)
Depth (ft)
0
2
4
6
8
10
12
100A-
NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar PCBs (ng/g)
0
2
4
6
8
10
12
72A
-NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar PCBs (ng/g)
Depth (ft)
Depth (ft)
0
2
4
6
8
10
12
98A-
NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar PCBs (ng/g)
0
2
4
6
8
10
12
68A
-NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar PCBs (ng/g)
Depth (ft)
Depth (ft)
0
2
4
6
8
10
12
99A-
NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar PCBs (ng/g)
0
2
4
6
8
10
12
69A
-NWB
14
0.1 1 10 100 1000 10000
Sum of Coplanar P CBs (ng/g)
Figure 1-8. Vertical profiles of individual cores collected close at the mouth of Passaic River (100A-NWB),
farther south in upper-Newark Bay (98A-NWB and 99-NWB) and mid-Newark Bay (72A-NWB; 68A-NWB
and 69A-NWB). PCBs are sum of coplanar congeners.
1-26
of radionuclide data. Consideration should be given to measuring radionuclides in areas such as this
as future sampling programs are developed for Newark Bay. This information will be of use in
confirming that the depositional rate is low in a region such as this, if in fact that is the case.
The sediment PCB data from the 1991 – 2001 time frame also show that PCB
concentrations vary laterally, across the width of the channel. For example, a comparison of
coplanar PCB congener levels in surface sediment collected east and west of mid-channel (Figure 1-
9) reveals significant (e.g., from less than 200 ng/g east of the mid-channel to close to 1000 ng/g
west of the mid-channel differences) in PCB concentrations (open vs. closed circles); it also shows
that significant differences occur within a cluster of samples collected from the same reach and river
mile (e.g., open circles at RM2-3). In addition, there is no clear pattern to the lateral distribution of
PCB levels – concentrations vary independently of the proximity to the shore. Further data analysis,
such as normalization of bulk chemical concentrations to organic carbon might help better explain
the lateral spatial distribution. Given that some regions in Newark Bay are likely to be depositional
areas, it is noteworthy that newly deposited solids have most probably altered the concentrations
that were previously measured in surficial sediments during the 1990s. In order to better
characterize the history of deposition until the present day, the low resolution program proposed for
the Passaic River, as described in the Field Sampling Plan Vol. 1 (Malcolm Pirnie, 2005b), should be
duplicated in Newark Bay. Such a program will be instrumental in tracking not only the