measuring success in cleanup: portland harbor baseline
TRANSCRIPT
Measuring Success in Cleanup: Portland Harbor
Baseline Sampling DesignSean Sheldrake
USEPA
Presentation Overview
• Site Background• Monitoring Types and Timeframes• Pre-Design Investigation (PDI) and Baseline Sample
Design• Sample Planning/Negotiation to Implementation• Results
Portland Harbor Site Vicinity Map
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Site
Site
Downtown Reach
Upriver Reach
Portland Harbor SiteLarge Number of
PRPs
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Background
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Portland Harbor Superfund Site RI/FS conducted between 2002 and 2016 COCs include PCBs, dioxins and furans, chlorinated pesticides, PAHs, metals and other chemicals
ROD issued in January 2017 Dredging (215 acres) Capping (150 acres) ENR (28 acres) MNR (1770 acres)
Development of a Site and upstream reach monitoring plan identified as a critical first step Establish baseline conditions prior to construction Developed with stakeholder input (State, natural resource agencies, tribes) in Q1/Q2 in 2017
Negotiated and Signed ASAOC with PRP Group in Q3/Q4 2017
Sediment Monitoring
Why?• Sediments are primary exposure pathway and focus of
remediation• Site has RAOs focused on sediment exposure and sediment
CULsStudy Questions• Are sediment concentrations declining?• Are sediment concentrations at the cleanup level?• Are sediment concentrations equivalent to upstream?
Data collection• Preliminary remedial footprint delineation (near term)
– Targeted sampling to refine SMAs• Baseline monitoring (near term)
– Develop a baseline for evaluating remedy performance• Remedial design characterization (intermediate)
– Detailed characterization to support remedial design• Construction monitoring (intermediate to long-term)
– Monitor construction activities• Long-term monitoring (long-term)
– Performance monitoring - evaluate whether the remedy is functioning as intended
– Remedial goal monitoring - evaluate progress towards achieving RAOs
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Presentation Focus
PDI and Baseline Sampling Design
PDI - Preliminary Remedial Footprint Delineation
• Location: SMA specific characterization– Some SMAs may move directly to remedial design (e.g., RM
11E and GASCO/Siltronic• Objective:
– Define/Refine remedial footprint of active remediation areas– Evaluate ENR/MNR including Swan Island Lagoon– Can be used to support remedial design sampling
• Media:– Surface and shallow subsurface sampling
• Timing:– Conduct in conjunction with baseline monitoring program
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Pre-Remedial Design Sampling• Goal is to delineate the vertical and horizontal extent
of contamination• Sediment cores to be installed on 150 foot intervals
– Potential step out cores as necessary to delineate horizontal extent of contamination
• Core depth up to 20’ dependent on area and remedial approach– Must be sufficient to delineate depth of contamination and
characterize material left behind• Characterization of focused COCs only (PCBs,
pesticides, dioxin and furans and PAHs)10
Pre-Design and Baseline Sampling Locations (Sediment/Surface Water)
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Baseline Design and Upstream Source
Evaluation• Stratified Random Surface
Sediment Sampling for current and future monitoring events– Measures effectiveness of
remedy over time (achievement to cleanup levels)
• 3-point composite samples randomly located within a grid; 424 site samples; 59 upstream samples
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Fish Tracking Receiver Locations
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Baseline and (future) Long-Term Monitoring
• Sediment – Sediment COCs– Surface sediment (upper 12”)– Sediment traps
• Biota – Fish Tissue COCs– Smallmouth bass
• Surface water – Surface Water and Groundwater COCs– Dissolved and total COC concentrations
Baseline Sampling (Fish Tissue)
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Sample Size Determination – Power Analysis
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Baseline Monitoring Design
Status and Summary• Pre-remedial design characterization
expected to be complete by Q2 2019; Q3 2019 Final Report
• Remedial design studies will take place on a SMA specific basis (3 areas underway, more expected in 2019)
• Additional Biota Sampling and Round 2 Baseline anticipated before Construction Begins (~2022)
• Construction monitoring will occur as part of remedy implementation
• Performance monitoring will take place concurrent with long-term monitoring
• Long-term monitoring will mimic baseline monitoring
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