Redwood Creek Characterization Report Redwood City, California
Total Page:16
File Type:pdf, Size:1020Kb
Erler & Kalinowski, Inc. Redwood Creek Characterization Report Redwood City, California Volume 1 of 2 Prepared by: Erler & Kalinowski, Inc. 1870 Ogden Drive Burlingame, California 94010 www.ekiconsult.com 9 November 2016 EKI B60048.03 Consulting engineers and scientists Erler & Kalinowski, Inc. Consulting Engineers and Scientists 1870 Ogden Drive Burlingame, CA 94010 (650) 292-9100 Fax: (650) 552-9012 9 November 2016 Ramana Chinnakotla City of Redwood City Director of Public Works 1400 Broadway Street Redwood City, CA 94063 Subject: Redwood Creek Characterization Report Redwood City, California (EKI B60048.03) Dear Mr. Chinnakotla: Erler & Kalinowski, Inc. (“EKI”) is pleased to submit the attached Redwood Creek Characterization Report, which has been prepared at the request of the City of Redwood City. The report summarizes and assesses the results of sediment sampling and surface water bacteriological sampling conducted in Redwood Creek and adjacent slough (“Study Area”). The Study Area is part of San Francisco Bay and is linked to the upland urban watershed by Redwood Creek. Please call us at (650) 292-9100 if you have any questions or comments regarding this report. Very truly yours, ERLER & KALINOWSKI, INC. Vera H. Nelson, P.E. C47418 Andrew N. Safford. P.E. C56084 Vice President Project Engineer cc (Electronic Copy): Donald Sobelman, Downey Brand, LLP Nicole Granquist, Downey Brand, LLP Michelle Marchetta Kenyon; Burke, Williams & Sorenson, LLP Oakland, CA (510) 452-5700 • Los Angeles, CA (310) 857-1600 • Centennial, CO (303) 796-0556 Redwood Creek Characterization Report City of Redwood City, California 9 November 2016 Volume 1 of 2 Prepared for: City of Redwood City Prepared by: Erler & Kalinowski, Inc. 1870 Ogden Drive Burlingame, California EKI B60048.03 Redwood Creek Characterization Report TABLE OF CONTENTS 1 Executive Summary ................................................................................................................... 1 1.1 Sediment Chemistry ......................................................................................................... 1 1.2 Potential Sources of Chemicals in Sediments .................................................................. 1 1.3 Potential Sediment Toxicity to Benthic Organisms ......................................................... 2 1.4 Potential Sediment Human Health Risks ......................................................................... 3 1.5 Surface Water Bacteriological Assessment...................................................................... 4 2 Introduction ................................................................................................................................ 7 2.1 Study Area and Vicinity ................................................................................................... 7 2.2 Sediment Chemistry ......................................................................................................... 7 2.3 Surface Water Bacteriological Assessment...................................................................... 8 2.4 Report Reliance ................................................................................................................ 9 3 Sediment Chemistry ................................................................................................................. 10 3.1 Sampling Depths and Laboratory Analyses Performed ................................................. 10 3.2 Types and Concentrations of COPCs Detected.............................................................. 10 4 Potential Sources of COPCs in Sediment Samples .................................................................. 12 4.1 Regional COPC Sources ................................................................................................ 12 4.2 Local COPC Sources ...................................................................................................... 14 4.3 Docktown Marina ........................................................................................................... 15 5 Toxicity of COPCs in Sediments to Benthic Organisms ......................................................... 18 5.1 Comparison to Ambient Values and Empirical SQBs ................................................... 18 5.2 Comparison to Mechanistic SQBs ................................................................................. 20 5.3 Comparison to Lines of Evidence .................................................................................. 21 EKI B60048.03 i November 2016 Redwood Creek Characterization Report 6 Screening Level Human Health Risk Assessment ................................................................... 25 6.1 Potential Exposure Scenarios ......................................................................................... 25 6.2 Beach Play Scenario ....................................................................................................... 26 6.3 Angler Fish Consumption Scenario ............................................................................... 26 6.4 Estimated Screening Level Human Health Risks .......................................................... 27 6.4.1 Beach Play Scenario ................................................................................................. 28 6.4.2 Angler Fish Consumption Scenario .......................................................................... 28 7 Surface Water Bacteriological Assessment .............................................................................. 32 7.1 Bacteriological Limits .................................................................................................... 32 7.2 Study Area Sample Locations and Sample Collection Schedule ................................... 34 7.3 Fecal Indicator Bacteria Laboratory Analyses ............................................................... 35 7.4 Fecal Indicator Bacteria Analytical Results ................................................................... 36 7.5 Fecal Indicator Bacteria Results at San Francisco Bay Beaches ................................... 37 8 Conclusions .............................................................................................................................. 39 8.1 Potential Sediment Toxicity to Benthic Organisms ....................................................... 39 8.2 Potential Sediment Human Health Risks ....................................................................... 40 8.3 Surface Water Bacteriological Assessment.................................................................... 40 9 References ................................................................................................................................ 42 EKI B60048.03 ii November 2016 Redwood Creek Characterization Report LIST OF TABLES 3-1 Comparison of Study Area Sediment Data with San Francisco bay Ambient Values and Effects-Range Median (“ERM”) Sediment Quality Benchmarks (“SQBs”) 4-1 Historical/Current Local Chemical Use Sites; Potential Sources of COPCs in Sediment 5-1 Comparison of Study Area Sediment Sample RWC-A1 Data with Mechanistic Sediment Quality Benchmarks 5-2 Comparison of Study Area Sediment Sample RWC-A2 Data with Mechanistic Sediment Quality Benchmarks 5-3 Comparison of Study Area Sediment Sample RWC-A3 Data with Mechanistic Sediment Quality Benchmarks 6-1 Screening Level Risk Assessment of Child and Adult Recreators at Tidal Flats Near Docktown Marina (RWC-A1) 6-2 Screening Level Risk Assessment of Child and Adult Recreators at Tidal Flats in Slough Area (RWC-A3) 6-3 Screening Level Risk Assessment of Adult Angler at Tidal Flats Near Docktown Marina (RWC-A1) 6-4 Screening Level Risk Assessment of Adult Angler at Tidal Flats in Slough Area (RWC-A3) 7-1 Bacteriological Limits for Recreation in Estuarine Water 7-2 Redwood Creek Surface Water Sample Bacteriological Analytical Results EKI B60048.03 iii November 2016 Redwood Creek Characterization Report LIST OF FIGURES 2-1 Vicinity Map 3-1 Sediment Sample Locations 4-1 Historical/Current Local Chemical Use Sites; Potential Sources of COPCs in Sediment 5-1 Core Sediment Sample Locations in San Francisco Bay 5-2 Comparison of Redwood Creek Selected COPC Concentrations with San Francisco Bay Ambient Values 7-1 Bacteriological Water Sampling Events to Occur Midway Between High and Low Tides 7-2 Bacteriological Water Sampling Locations 7-3 Bacteriological Water Sample Locations in San Francisco Bay VOLUME 2 LIST OF APPENDICES A Pacific EcoRisk. May 2011. Data Report, Sediment Characterization Sampling and Analysis Results (SAR) for the Redwood Creek Sediments. B Environmental Data Resources, Inc. Report C Bacteriological Field Sampling Procedures D Bacteriological Laboratory Analytical Reports and Chain of Custody Forms E Fecal Indicator Bacteria Results from San Francisco Bay Beaches in San Mateo County EKI B60048.03 iv November 2016 Redwood Creek Characterization Report ACRONYMS AND ABBREVIATIONS APHA American Public Health Association AVS acid volatile sulfide Basin Plan 2015 San Francisco Bay Basin Plan BCDC Bay Conservation and Development Commission bgs below ground surface bml below mud line BPTCP Bay Protection and Toxic Cleanup Program BSAF biota-sediment accumulation factor COPC chemicals of potential concern identified in San Francisco Estuary Regional Monitoring Program CWA Clean Water Act CWQC California Water Quality Council DDT dichlorodiphenyltrichloroethane DHS Department of Health Services DTSC Department