Real Property Institute of Canada 2014 RPIC Federal Contaminated - PowerPoint PPT Presentation

Real Property Institute of Canada 2014 RPIC Federal Contaminated Sites National Workshop April 2014

2 / 37 Esquimalt Graving Dock Waterlot Remediation Project (Phase 1B) Confirmatory Sampling, Analysis and Evaluation Plan (CSAEP) Implementation and Dredging Residuals Management Stream H: Contaminated Sites Management for Aquatic Environments and Sediment Presenter: David McKeown (SLR Consulting) Collaborators: Jeff Nyman (SLR), Andrew Mylly (PWGSC), Rae Ann Sharp (PWGSC), Tom Wang (Anchor QEA), Dan Berlin (Anchor QEA), Matt Woltman (Anchor QEA)

3 / 37 Project Background • The EGD is a federally owned, operated and maintained facility. • Ship repair and maintenance facility for military and civilian vessels since 1927. • Industrial activities at the EGD have resulted in contamination of the surrounding sediments. • PWGSC managed the remediation project through FCSAP funding. • The Waterlot Remediation Program aimed to clean up the site to meet federal and provincial environmental standards.

4 / 37 Project Background (Cont’d) • Primary CoCs in sediment included Metals, PAH, and PCB. • Other contaminants included TBT, Dioxins/Furans, and Pesticides. • Contaminant levels identified as IL+ for disposal considerations. • Contaminated sediments were removed through remedial dredging and off-site disposal. • Confirmatory sediment sampling program designed and implemented to verify that remedial targets were met. • Decision criteria developed to determine potential re- dredging and/or Remedial Management Cover (RMC) placement requirements.

5 / 37 Project Location Esquimalt Graving Dock

6 / 37 Project ¡Boundary ¡

7 / 37 Photo ¡courtesy ¡of ¡Heath ¡Moffa5 ¡

8 / 37 Objectives • CSAEP developed to outline standardized procedures for collection of post-dredge sediment samples. • Establish methods to characterize and assess post-dredge sediment quality. • Provide an evaluation process to verify whether remedial targets were met through dredging activities. • Provide project staff with a guidance tool to conduct sampling, assess resulting information, and determine whether additional actions were required. • Also used as a baseline planning tool for cost estimates to implement the sediment quality assessment program.

9 / 37 Study Design • Waterlot divided into 11 dredge zones based on pre-dredge contaminant profiles. – Zone 10 further broken into sub-zones • Dredge zones sampled after completion of dredging activities using a 25 x 25 m grid spacing. • Locations identified in field using sub-metre accuracy GPS • Vibracore samples collected at each location with concurrent surface grab samples (petite ponar). • Diver cores collected where unable to obtain vibracore samples. • Test pit samples collected during low tide in Photo ¡courtesy ¡of ¡Heath ¡Moffa5 ¡ intertidal area of Munroe Head.

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11 / 37 Study Design • Sediment quality assessment conducted for each dredge zone and sub-zone individually. • Confirmatory sediment cores and concurrent grab samples collected at each location for analytical testing. – Cores were sampled at 0.5 m intervals to identify missed inventory contamination. – Surface grab samples were used to identify dredge residual contamination. • Slope samples also collected prior to slope armouring to aid in future risk assessment updates. – Not included in re-dredge decisions due to geotechnical considerations. • Over 200 post-dredge locations sampled.

12 / 37 Remedial Objectives • Numeric Remedial Action Objectives: – Based on most stringent and previously accepted applicable marine environmental quality guidelines, including: • CCME Marine Sediment PEL • BC CSR Sediment Criteria for Typical Contaminated Sites • Puget Sound Dredge Disposal Analysis & Site-specific TBT assessment (Golder) • NRAOs derived for: – Metals – PAH – PCB – Dioxins & Furans – TBT – Select Pesticides

13 / 37 Sample Collection, Handling and Processing • Core samples collected by vibracoring vessel. • Cores advanced in to sea floor 2 to 3 m or until refusal. • Core tubes cut open to facilitate sample processing. • Core compaction corrections applied based on penetration depth vs. recovery core length. – Minimum recovery targets established for acceptance of cores.

14 / 37 Sample Collection, Handling and Processing • Samples collected at 0.5 m intervals along cores. – Upper 1.0 m samples submitted for analysis. – Remaining samples archived. • Samples homogenized within each interval to ensure representative samples.

15 / 37 Sample Collection, Handling and Processing Diver assisted grabs/cores collected Concurrent grab samples collected where vibracoring was not possible (e.g., using petite ponar sampler. dry dock sill area, hard substrate areas).

16 / 37 Sample Collection, Handling and Processing All grab, core, test pit samples Munroe Head intertidal area homogenized to be representative. (Zone 9) sampled by test- pitting during low tides.

17 / 37 Laboratory Coordination and Submissions • Prepared Laboratory Statement of Requirements to define: – Required detection limits to meet NRAO levels. – Turn-around-times for specific parameters. – Detailed schedule for samples and analysis requirements on a daily, weekly and monthly basis. – Communication requirements. – Data management and QA/QC requirements. • Electronic COC submissions. • Sample pick-up/delivery coordinated through laboratory.

18 / 37 Data Management • Dedicated web-based Environmental Management Tool (EMT) developed to provide accessible and up to date data repository. • Remote access for project personnel. • Laboratory results loaded automatically to the EMT. • Data manager included on project to provide QA/QC review, data tabulation and management, and statistical analysis. • Sediment quality compared to NRAOs

19 / 37 Data Management (EMT)

20 / 37 Confirmatory Sample Assessment • Post-dredge compliance decision framework generated for assessment of sediment quality. • Post-dredge sediment quality was assessed using two methods: – Overall dredge zone compliance with NRAOs based on statistical approach (surface samples only). – Single point compliance assessment. • Surficial samples compared to 4X NRAO threshold to assess dredge residual contamination. – Considered eventual mixing of upper sediment layers (up to 10 cm) with placed RMC layer (30 cm) • Core samples compared to 1X NRAO to assess missed inventory contamination.

21 / 37 Re-Dredge Decision Process • Initial re-dredge decision based on 3-day TAT parameters (metals, PAH, PCB). – These parameters were drivers in most zones and other contaminants (i.e., pesticides, TBT, dioxins/furans) were generally shown to co-locate. – Pesticides, TBT, dioxins/furans analyzed on a 7-day TAT. – Where other parameters were drivers within a zone, results were re- assessed once they became available. – Modifications to the re-dredge decision were then provided to the contractor. • 10-day turn around requirement in specifications to provide re- dredge decision to contractor. • Consultant design team and PWGSC personnel reviewed information from each zone in accordance with decision framework. – Re-dredge decisions formally relayed to contractor through PWGSC. 21 / 37

22 / 37 Re-Dredge Decision Process • Contingency re-dredge depths determined based on whether residual or missed inventory contamination was present within dredge zone and/or each sampling grid. • Additional surface grab samples collected following re-dredging. • Sediment quality from second sampling round was re-assessed in accordance with the post-dredge Photo ¡courtesy ¡of ¡Heath ¡Moffa5 ¡ compliance decision framework. – Residuals assessment only.

23 / 37 Post-Dredge Compliance Decision Framework ZONE DREDGING COMPLETED CONFIRMATORY SAMPLING (Vibracore and Surface Sampling) CORE SAMPLING SURFACE Archive Samples (0 – 2.0 m with min 75% recovery) below 1.0 m SAMPLING Composite samples to lab (in 0.5 m intervals) (0 – 0.1 m) (0-0.5 m and 0.5-1.0 m) Analytical Data Receipt, Tabulation and Review Lab analysis (3-7 working days)

24 / 37 Post-Dredge Compliance Decision Framework COMPLIANCE UNIT ASSESSMENT (based on surface samples only) Method 1 – Single Sample Assessment Method 2 – Statistical Approach Are the surface Are there any Is the 90 th Percentile or sample surface sample 95% UCLM surface sample concentrations concentrations concentrations below NO ¡ YES ¡ less than NRAO? >4X NRAO? NRAO? YES ¡ NO: ¡<4X ¡NRAO ¡ NO: ¡>4X ¡NRAO ¡ RESIDUAL RE- RESIDUAL RE- If ¡<4X ¡NRAO ¡ DREDGE DREDGE PLACE RMC YES ¡ NO: ¡<4X ¡NRAO ¡ (0-0.3 m) (0-0.3 m) 2 nd Round Surface Sampling 2nd Round Surface Sampling If ¡<NRAO ¡ Is the 90 th Percentile or 95% UCLM surface sample concentrations NO FURTHER YES ¡ ACTION below NRAO? If No, RMC thickness REQUIRED to be evaluated based on in-situ concentrations