BASELINE ECOLOGICAL RISK ASSESSMENT SAN JACINTO RIVER WASTE PITS SUPERFUND SITE Prepared for McGinnes Industrial Maintenance Corporation International Paper Company U.S. Environmental Protection Agency, Region 6 Prepared by Integral Consulting Inc. 411 1st Avenue S, Suite 550 Seattle, Washington 98104 August 2012 Revised May 2013 BASELINE ECOLOGICAL RISK ASSESSMENT SAN JACINTO RIVER WASTE PITS SUPERFUND SITE Prepared for McGinnes Industrial Maintenance Corporation International Paper Company U.S. Environmental Protection Agency, Region 6 Prepared by Integral Consulting Inc. 411 1st Avenue S, Suite 550 Seattle, Washington 98104 August 2012 Revised May 2013 TABLE OF CONTENTS 1 INTRODUCTION ............................................................................................................ 1-1 1.1 Purpose ......................................................................................................................... 1-1 1.2 Document Organization .............................................................................................. 1-2 2 BACKGROUND INFORMATION ................................................................................... 2-1 2.1 Site Setting and General Conceptual Site Models ...................................................... 2-1 2.2 Baseline Risk Assessment Datasets and Data Treatment Rules ................................. 2-3 2.2.1 Baseline Dataset ...................................................................................................... 2-3 2.2.2 Data Treatment Rules ............................................................................................. 2-5 3 PROBLEM FORMULATION ........................................................................................... 3-1 3.1 Chemicals of Potential Ecological Concern ................................................................ 3-2 3.2 Overview of Ecological Effects .................................................................................... 3-2 3.2.1 Evaluating Exposure and Toxicity of “Dioxin-Like” Compounds ....................... 3-3 3.2.2 TEQ Nomenclature ................................................................................................ 3-4 3.2.3 Mechanisms of Toxicity ......................................................................................... 3-5 3.2.4 Overview of Toxicity to Ecological Receptors...................................................... 3-6 3.2.4.1 Benthic Macroinvertebrates ......................................................................... 3-6 3.2.4.2 Fish ................................................................................................................. 3-7 3.2.4.3 Reptiles ........................................................................................................... 3-8 3.2.4.4 Birds ................................................................................................................ 3-9 3.2.4.5 Mammals ........................................................................................................ 3-9 3.3 Fate and Transport of Chemicals of Potential Ecological Concern ......................... 3-10 3.4 Ecosystems Potentially at Risk .................................................................................. 3-11 3.4.1 Upland Habitats .................................................................................................... 3-11 3.4.2 Upland Wildlife .................................................................................................... 3-12 3.4.3 Aquatic and Riparian Habitats ............................................................................. 3-12 3.4.3.1 Fish and Invertebrates ................................................................................. 3-13 3.4.3.2 Shorelines and Wetlands ............................................................................. 3-13 3.4.3.3 Aquatic Wildlife .......................................................................................... 3-14 3.4.3.4 Effect of TCRA Construction ...................................................................... 3-15 3.4.4 Endangered and Threatened Species at the Site ................................................. 3-16 Baseline Ecological Risk Assessment August 2012; Revised May 2013 San Jacinto River Waste Pits Superfund Site iii 090557-01 3.5 Ecological Receptors and Receptor Surrogates ......................................................... 3-18 3.6 Assessment Endpoints and Risk Questions ............................................................... 3-19 3.7 Ecological Conceptual Site Models ........................................................................... 3-20 3.8 Ecological Risk Analysis Plan .................................................................................... 3-21 3.8.1 Ecological Risk Assessment Approach ................................................................ 3-21 3.8.2 Exposure Assessment ............................................................................................ 3-23 3.8.2.1 Measures of Exposure .................................................................................. 3-23 3.8.2.2 Exposure Units and Calculation of Exposure Point Concentrations ........ 3-24 3.8.2.3 Exposure Algorithms ................................................................................... 3-25 3.8.2.4 Exposure Assumptions ................................................................................ 3-25 3.8.3 Effects Assessment ................................................................................................ 3-26 3.8.4 Risk Characterization and Uncertainty Analysis................................................ 3-27 3.8.4.1 Calculation of Hazard Quotients ................................................................ 3-27 3.8.4.2 Probabilistic Risk Evaluation ...................................................................... 3-28 3.8.4.3 Evaluation of Post-TCRA Risk ................................................................... 3-29 3.8.4.4 Risks to Populations of Ecological Receptors ............................................ 3-29 3.8.4.5 Comparison of Site Risks to Background ................................................... 3-29 4 EXPOSURE ASSESSMENT .............................................................................................. 4-1 4.1 Exposure of Benthic Macroinvertebrates ................................................................... 4-1 4.1.1 Estimated Porewater Concentrations .................................................................... 4-2 4.1.2 Datasets Used to Evaluate Risk to Benthic Macroinvertebrates .......................... 4-4 4.1.3 Results of the Benthic Macroinvertebrate Exposure Evaluation ......................... 4-5 4.2 Exposure of Fish ........................................................................................................... 4-5 4.2.1 COPCE Concentrations in Fish Diets ..................................................................... 4-6 4.2.2 Estimated Concentrations of Selected COPCEs in Surface Water ....................... 4-7 4.2.3 Concentrations of PCBs and Dioxin-Like Compounds in Whole Fish ............... 4-8 4.2.4 Unit Conversions .................................................................................................... 4-9 4.2.5 Datasets Used to Evaluate Exposure to Fish ........................................................ 4-10 4.2.6 Results of Fish Exposure Assessment .................................................................. 4-11 4.3 Exposure of Reptiles, Mammals, and Birds ............................................................... 4-12 4.3.1 Wildlife Exposure Model ..................................................................................... 4-13 4.3.1.1 Ingestion of Multiple Prey Types ............................................................... 4-14 4.3.1.2 Relative Bioavailability Adjustment Factor ............................................... 4-15 Baseline Ecological Risk Assessment August 2012; Revised May 2013 San Jacinto River Waste Pits Superfund Site iv 090557-01 4.3.1.3 Unit Conversions ......................................................................................... 4-18 4.3.1.4 Estimation of Concentrations in Whole Fish ............................................ 4-19 4.3.1.5 Concentrations of COPCEs in Foods of Alligator Snapping Turtle, Killdeer, Raccoon, and Marsh Rice Rat .................................................................... 4-19 4.3.1.6 Wildlife Exposure Units .............................................................................. 4-25 4.3.1.7 Calculation of Exposure Point Concentrations .......................................... 4-27 4.3.1.8 Data Used ..................................................................................................... 4-29 4.3.1.9 Results .......................................................................................................... 4-29 4.3.2 Estimated TEQ Concentrations in Bird Eggs ...................................................... 4-30 4.3.2.1 Estimating Dioxins and Furans in Bird Eggs .............................................. 4-30 4.3.2.2 Estimating PCB Concentrations in Bird Eggs ............................................ 4-34 4.3.2.3 Egg Exposure Scenarios ............................................................................... 4-37 4.4 Probabilistic Exposure Assessment ..........................................................................