Sediment Stability in the Lower Passaic River Integration of Multiple Lines of Evidence

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1 Sediment Stability in the Lower Passaic River Integration of Multiple Lines of Evidence Fourth Passaic River Symposium June 22, 21 Michael Barbara, mab.consulting, LLC Marcia Greenblatt, AECOM John Connolly, Anchor QEA

LPRRP Remedial Investigation Performed by the Cooperating Parties Group Critical study to fully characterize site for selection of optimal remedies Dundee Dam Hudson River Saddle River RI Activities

2 LPRRP Remedial Investigation Performed by the Cooperating Parties Group Critical study to fully characterize site for selection of optimal remedies Dundee Dam Hudson River Saddle River RI Activities include: Sequential bathymetric surveys Sediment coring program Benthic and fish tissue collection Water column (physical and chemical) data collection Hydrodynamic, sediment transport, and chemical fate and transport models Lower Passaic River Arthur Kill Third River Second River Newark Bay Kill van Kull Hackensack River June 29, 21 Page 2

Sediment Stability Assessment Lines of evidence that must be considered in the evaluation of sediment stability in the LPR: Time trends in surface sediment COPC concentrations Patterns of deposition

3 Sediment Stability Assessment Lines of evidence that must be considered in the evaluation of sediment stability in the LPR: Time trends in surface sediment COPC concentrations Patterns of deposition in the sediment bed Vertical patterns of COPC concentrations in sediment cores Especially for larger sites, a lines of evidence approach should be used to evaluate the extent of sediment and contaminant movement and resultant exposure for various areas of the water body. - EPA Contaminated Sediment Remediation Guidance for Hazardous Waste Sites, 2. Sedimentation rates in sediment cores Predicted bottom shear stresses Measured changes in river bathymetry Modeling of sediment transport June 29, 21 Page 3

4 28 Low Resolution Coring Program Summary 11 cores Along the 17.4 miles of the LPR In the major tributaries and Dundee Canal In Dundee Lake Chemical data Dioxins PCBs (aroclors, congeners, homologs) Pesticides (HRMS, 881) Herbicides Metals, titanium, Hg, butyltins, CN VOCs, SVOCs, PAHs, TEPH Radiochemistry data Be-7, Cs-137, Pb-21, K4 Physical data Grain size, specific gravity, bulk density, Atterberg Limits Page 4

5 Sediment Stability Assessment Lines of evidence that must be considered in the evaluation of sediment stability in the LPR: Time trends in surface sediment COPC concentrations Patterns of deposition in the sediment bed Vertical patterns of COPC concentrations in sediment cores Sedimentation rates in sediment cores Predicted bottom shear stresses Measured changes in river bathymetry Modeling of sediment transport June 29, 21 Page

6 Cs-137 Profile Dating Markers Declining Cs-137 concentrations Cs-137 pci/g Net sedimentation rate =.7 ft/yr Mid-Depth (ft) 1 Introduction of Cs-137 to the atmosphere 194 sediment horizon Net sedimentation rate =.3 ft/yr Peak Cs-137 to the atmosphere 1963 sediment horizon 2 Page 6

7 Mid-Depth (ft) 1 Cs-137 pci/g RM Example Undisturbed Cs-137 Profiles from the LRC 2 Cs-137 pci/g Cs-137 pci/g Mid-Depth (ft) 1 7 RM.41 Mid-Depth (ft) 1 3 RM Page 7

Example Disturbed Cs-137 Profiles from the LRC Mid-Depth (ft) 1 Cs-137 pci/g.1.2.3.4.

8 Example Disturbed Cs-137 Profiles from the LRC Mid-Depth (ft) 1 Cs-137 pci/g Saddle River 2 Cs-137 pci/g..1. Cs-137 pci/g Mid-Depth (ft) 1 49 RM 7.86 Mid-Depth (ft) RM -. Page 8

9 Classification of Cs-137 Profiles Classification of Core Onset (194) Peak (1963) Decrease Near Surface A X X X Summary Well-maintained profile, onset and burial evident. Provides three markers for calculation of three sedimentation rates. B -- X X C X D Measurable peak, burial evident, but no onset. Only two markers for calculation of one sedimentation rate. May have little/no burial at the surface, but onset evident. One sedimentation rate can be calculated. Cs-137 may or may not be present. If present no pattern indicative of consistent deposition. Page 9

10 Classification of Cs-137 Profiles 18 Dundee Lake Number of Cores % cores with A or B Cs-137 profiles All LPR Cores 92 4% RM % RM % RM % > RM % Model predicts high velocities Last dredged in Last dredged in Cs-137 Profile Classification A B C D Page 1

11 Sediment Stability Assessment Lines of evidence that must be considered in the evaluation of sediment stability in the LPR: Time trends in surface sediment COPC concentrations Patterns of deposition in the sediment bed Vertical patterns of COPC concentrations in sediment cores Sedimentation rates in sediment cores Predicted bottom shear stresses Measured changes in river bathymetry Modeling of sediment transport June 29, 21 Page 11

12 Vertical Chemical Profiles 2,3,7,8-TCDD (ng/kg) Total DDx (mg/kg) Mercury (mg/kg) Depth (ft) Page 12

13 Vertical Chemical and Cs-137 Profiles 2,3,7,8-TCDD (ng/kg) Total DDx (mg/kg) Mercury (mg/kg) Depth (ft) Cesium-137 (pci/g) Cesium-137 (pci/g) Cesium-137 (pci/g) Page 13

14 Percent of LRC locations where the depth of the peak COPC concentration was at or below the depth of the peak Cs-137 concentration 1% 8% 6% 4% 2,3,7,8-TCDD Total PCBs Total DDx Total HMW PAH Mercury 2% % RM -1 RM 1-8 RM 8-12 > RM 12 Page 14

15 Cs-137 and COPC Profiles have Generally Remained Stable through Several Large Flow Events 2 18 ~1 in 4 year flow 16 Daily Average Flow at Little Falls (cfs) Sep- Sep-6 Sep-7 Sep-8 Sep-9 Sep- Sep-1 Page

16 Sediment Stability Assessment Lines of evidence that must be considered in the evaluation of sediment stability in the LPR: Time trends in surface sediment COPC concentrations Patterns of deposition in the sediment bed Vertical patterns of COPC concentrations in sediment cores Sedimentation rates in sediment cores Predicted bottom shear stresses Measured changes in river bathymetry Modeling of sediment transport June 29, 21 Page 16

17 High surficial concentrations observed at locations with low burial rates Page 17

18 Cs-137 pci/g Mid-Depth (ft) 1 4 RM 7. 2 Cs-137 pci/g Mid-Depth (ft) 1 67 RM 1.93 Cs-137 pci/g Mid-Depth (ft) 1 7 RM February 21 Page 18

19 LRC provides important lines of evidence to support sediment stability evaluation The sediment bed has generally been stable over the past 4 years. Geomorphology and dredging history can explain sedimentation patterns The peak chemical concentrations are generally buried at depth and are most commonly at or below the 1963 sediment horizon. Surficial chemical concentrations are influenced by burial rate. High surficial chemical concentrations are observed at locations with low burial rate. Page 19

20 Questions?

Source Control Early Action Focused Feasibility Study

Source Control Early Action Focused Feasibility Study Empirical Mass Balance Model Results or the Lower Passaic River Edward A. Garvey, PhD, PG Malcolm Pirnie, Inc. Remedial Options Workgroup Meeting June