United States Environmental Protection 1200 PennsylvaniaAvenue,N.W. Agency Washington, D.C. 20460 March 2010 Office of Solid Waste and Emergency Response Support Document for the Revised National Priorities List Final Rule – Gowanus Canal Support Document for the Revised National Priorities List Final Rule Gowanus Canal March 2010 Site Assessment and Remedy Decisions Branch Office of Superfund Remediation and Technology Innovation Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, DC 20460 Gowanus Canal NPL Listing Support Document March 2010 Table of Contents Executive Summary ...................................................................................................................................iii Introduction................................................................................................................................................iv Background of the NPL...........................................................................................................................iv Development of the NPL..........................................................................................................................v Hazard Ranking System ...........................................................................................................................v Other Mechanisms for Listing.................................................................................................................vi Organization of this Document...............................................................................................................vii Glossary..................................................................................................................................................vii 1. List of Commenters and Correspondence ....................................................................................1 2. Site Description .............................................................................................................................62 3. Summary of Comments................................................................................................................63 3.1 Support for Listing and General Opposition Comments ...............................................................66 3.2 Evaluation of Other Pathways .......................................................................................................68 3.3 Request for Extension....................................................................................................................69 3.4 Extent of Site .................................................................................................................................69 3.5 Non-listing Activities.....................................................................................................................71 3.6 Site-specific Risk ...........................................................................................................................76 3.7 Alternatives to Listing....................................................................................................................79 3.8 Superfund and Combined Sewer Overflow ...................................................................................85 3.9 Executive Order 12866 ..................................................................................................................86 3.10 Regulatory Flexibility Act .............................................................................................................90 3.11 Economic Impacts of Listing.........................................................................................................90 3.12 Proper Notice .................................................................................................................................92 3.13 USACE Activities..........................................................................................................................93 3.14 Possible Impacts of Delaying Listing ............................................................................................93 3.15 HRS Concept .................................................................................................................................94 3.16 Consideration of Fish Advisory.....................................................................................................96 3.17 Use of Surface Water or Fish Tissue Samples...............................................................................98 i Gowanus Canal NPL Listing Support Document March 2010 3.18 Likelihood of Release ..................................................................................................................101 3.18.1 QA/QC Protocols ............................................................................................................................101 3.18.1.1 Use of QA/QC Samples ..............................................................................................................101 3.18.1.2 Chain-of-Custody........................................................................................................................102 3.18.1.3 Sample Integrity..........................................................................................................................104 3.18.2 Screening Benchmarks....................................................................................................................106 3.18.3 Sample Moisture Content................................................................................................................108 3.19 Contaminated Sediment Source...................................................................................................109 3.20 Unallocated Sources.....................................................................................................................115 3.20.1 Identification of an Unallocated Source ..........................................................................................115 3.20.2 Waste Quantity based on Unallocated Source.................................................................................117 3.21 Volume Estimate Reflecting Bioavailability ...............................................................................121 3.22 HRS Source Characterization (Hazardous Substances/Hazardous Waste)..................................123 3.23 Inclusion of PCBs in the HRS Evaluation ...................................................................................127 3.24 Waste Characteristics: Inclusion of Benzo(a)pyrene and PAHs in HRS Evaluation...................131 3.25 Background Location...................................................................................................................134 3.26 Likelihood of Release: Other Data Sets......................................................................................137 3.27 Waste Characteristics: Bioaccumulation ....................................................................................140 3.28 Human Food Chain Fishery: Evidence of Consumption .............................................................144 3.29 Targets: Fishery Production.........................................................................................................147 3.30 Targets: Fishery in Upper New York Bay ...................................................................................148 3.31 Resources .....................................................................................................................................151 3.32 Surface Water Overland/Flood Migration Component – Environmental Threat Scoring Methodology.........................................................................................................................................152 4. Conclusion ...................................................................................................................................155 Attachment 1 Record of Meetings Regarding Proposed NPL Listing of Gowanus Canal Attachment 2 USACE Sampling and Analysis Plan Attachment 3 Background Samples and Release Samples from the GEI Analysis ii Gowanus Canal NPL Listing Support Document March 2010 Executive Summary Section 105(a)(8)(B) of CERCLA, as amended by SARA, requires that the EPA prepare a list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States. An original National Priorities List (NPL) was promulgated on September 8, 1983 (48 FR 40658). CERCLA requires that EPA update the list at least annually. This document provides responses to public comments received on the Gowanus Canal site, proposed on April 9, 2009 (74 FR 16162). This site is being added to the NPL based on an evaluation under EPA’s Hazard Ranking System (HRS) in a final rule published in the Federal Register in March 2010 iii Gowanus Canal NPL Listing Support Document March 2010 Introduction This document explains the rationale for adding the Gowanus Canal site in Brooklyn, New York, to the National Priorities List (NPL) of uncontrolled hazardous waste sites and also provides the responses to public comments received on this site. The EPA proposed this site on April 9, 2010 (74 FR 16162). This site is being added to the NPL based on an evaluation under the Hazard Ranking System (HRS) in a final rule published in the Federal Register in March 2010. Background of the