Anaheim_Bay_2017_Final_SAR_01112018.pdf

SAMPLING AND ANALYSIS PLAN REPORT

Anaheim Bay Harbor Geotechnical and Environmental Investigation Project

Task Order No. CQ02, USACE Contract No. W912P7-1-D-0005

Prepared for:

U.S. Army Corps of Engineers

Los Angeles District Los Angeles, California

Prepared by:

DiazYourman – GeoPentech – Kinnetic Laboratories/ Joint Venture 1616 E. 17th Street

Santa Ana, CA 92705

January 2018

GeoPentech i

DISTRIBUTION LIST

Mr. Blake Horita, Project Manager PPMD Navigation and Coastal Projects Branch U. S. Army Corps of Engineers, Los Angeles District Blake.M.Horita@usace.army.mil

Mr. Ken Kronschnabl KLI Project Manager Kinnetic Laboratories, Inc.

kkronsch@kinneticlabs.net

Mr. Jeffrey Devine, Technical Manager U. S. Army Corps of Engineers, Los Angeles District Jeffrey.D.Devine@usace.army.mil

Ms. Kelly Shaw Field Geotechnical Leader Diaz Yourman Kelly Shaw <Kelly@diazyourman.com>

Mr. Steve Estes Project Environmental/Regulatory Scientist U. S. Army Corps of Engineers, Los Angeles District

Mr. Allen Yourman Joint Venture Project Manager Diaz Yourman Associates, GeoPentech, and Kinnetic Laboratories Joint Venture Allen@diazyourman.com

Mr. Larry Smith, Technical Manager U. S. Army Corps of Engineers, Los Angeles District Lawrence.J.Smith@usace.army.mil

Mr. Christopher Diaz Geotechnical Manager Diaz Yourman & Associates chris@diazyourman.com

Mr. Doug Shibberu Santa Ana Regional Water Quality Control Board Doug.Shibberu@waterboards.ca.gov

Ms. Carla Hollowell Project Manager Eurofins Calscience CarlaHollowell@eurofinsUS.com

Mr. Jun Zhu Los Angeles Regional Water Quality Control Board

Mr. Spencer Johnson Field Operations Manager Kinnetic Laboratories, Inc.

sjohnson@kinneticlabs.com

Ms. Melisa Scianni United States Environmental Protection Agency- Region 9 scianni.melissa@epa.gov

Ms. Amy Howk KLI QA/QC Management Kinnetic Laboratories, Inc.

ahowk@kinneticlabs.net

Mr. Larry Simon Federal Consistency Coordinator Energy, Ocean Resources and Federal California Coastal Commission lsimon@coastal.ca.gov

Mr. Jon Toal Health and Safety Management Kinnetic Laboratories, Inc.

jtoal@kinneticlabs.com ii

Anaheim Bay Harbor Geotechnical and Environmental Investigation Project

Task Order No. CQ02, USACE, Contract No. W912P7-16-D-0005

TABLE OF CONTENTS

Page No.

1.0 INTRODUCTION

1.1 Project Summary

1.2 Site Location

1.3 Roles and Responsibilities

2.0 SITE HISTORY AND HISTORICAL DATA REVIEW

2.1 Site Setting and Potential Sources of Contamination

2.2 Previous Anaheim Bay Dredging Episodes

2.3 Previous Testing Episodes

2.3.1 USACE Maintenance Dredging Evaluations

2.3.2 U.S. Navy Maintenance and Construction Dredging Evaluation

3.0 METHODS

3.1 Dredge Design

3.2 Sampling and Testing Design

3.2.1 Anaheim Bay Harbor Sample Identification, Sediment Collection and Composite Formation

3.2.2 Reference Sediment Collection

3.2.3 Environmental Testing

3.2.4 Geotechnical Samples and Testing

3.2.5 Summary of Anaheim Bay Harbor Testing and Evaluation Sequence

3.2.6 Evaluation Guidelines

3.3 Field Sampling Protocols

3.3.1 Positioning and Depth Measurements

3.3.2 Vibracore Sampling Methods

3.3.3 Vibracore Decontamination

3.3.4 Core Processing

3.3.5 Beach Nearshore Area Grab Samples

3.3.6 LA-2 Reference and Control Sediments

3.3.7 Water Sampling

3.3.8 Detailed Sediment Log

3.3.9 Documentation and Sample Custody

3.4 Laboratory Testing Methods

3.4.1 Geotechnical Testing

3.4.2 Bulk Sediment Chemical Analyses

3.4.3 Elutriate Preparation Methods and Chemical Analysis

3.4.4 Tier III Biological Testing

4.0 RESULTS

4.1 Sediment Physical Results

iii

4.2 Sediment Chemistry Results

4.3 Solid Phase Bioassay Results

4.4 Suspended Particulate Phase (SPP) Bioassay Results

4.5 Bioaccumulation Results

5.0 DISCUSSION

5.1 Sediment Observations

5.2 Sediment Grain Size

5.3 Bulk Sediment Chemistry

5.4 Benthic (Solid Phase) Bioassays

5.5 SPP (Suspended Particulate Phase) Water Column Bioassays

5.5 1 48-Hour Mussel Larvae Survival and Normal Embryonic Development Test

5.5.2 96-Hour Mysid Survival Test

5.5.3 96-Hour Juvenile Fish Survival Test

5.5.4 SPP Testing Conclusion

5.6 Bioaccumulation Survival

5.7 Assessment of Bioaccumulation Potential

5.8 Conclusions and Recommendations

6.0 QUALITY CONTROL REQUIREMENTS

6.1 Field Sampling Quality Management

6.2 Analytical Chemistry QA/QC

6.4 Biological Testing

7.0 REFERENCES CITED

APPENDICES

APPENDIX A Anaheim Bay Harbor Sediment Analytical Results from 2008

(Geomatrix, 2008).

APPENDIX B Anaheim Bay Harbor Summary Tier III Testing Results from 2009

(Kinnetic Laboratories and Diaz Yourman and Associates, 2009).

APPENDIX C Anaheim Bay Harbor Summary Analytical Results from 2009 (Kinnetic

Laboratories and Diaz Yourman and Associates, 2009).

APPENDIX D U.S. Navy 2016 Dredge Material Evaluation Sampling and Analysis

Report (Tierra Data, 2016).

APPENDIX E USACE Beach Physical Compatibility Report APPENDIX F Core Photographs APPENDIX G Sediment Logs APPENDIX H Field Data Logs APPENDIX I Analytical Laboratory Reports APPENDIX J Bioassay Laboratory Report APPENDIX K Grain Size Distribution Plots APPENDIX L Analytical Quality Assurance/Quality Control Report iv

LIST OF TABLES

Page No.

Table 1. 2017 Dredge Area Project Elevations and Volume Estimates for Anaheim Bay Harbor

Table 2. Project Team and Responsibilities Table 3. Key Project Contacts Table 4. Actual Sampling Location Coordinates, Date and Time of Sampling, Core Depths, Mudline Elevations, and Sampling Elevations for the 2017 Anaheim Bay Harbor Sampling and Testing Program

Table 5. Date, Times and Sampling Coordinates for Samples Collected from the Surfside Subset Beach Nearshore Placement Area

Table 6. Sediment Analytical Methods and Target Quantitation Limits Table 7. Species, Methods, and End-Points for Biological Testing Table 8. Analytical Methods and Quantitation Limits Achieved for the Tissue Samples Table 9. Anaheim Bay Harbor Sieve Analysis Data Table 10. Surfside-Sunset Beach Nearshore Area Sieve Analysis Data Table 11. 2017 Anaheim Bay Harbor Composite Bulk Sediment Chemistry Results Table 12. Survival Results for the 10-day Ampelisca abdita Bioassays Table 13. Survival Results for the 10-day Neanthes arenaceodentata Bioassays Table 14. Sediment Porewater Initial Water Quality Characteristics for the Bioassay Test

Sediments Table 15. Replicate and Mean Survival and Normal Development Results and Median Effective and Lethal Concentrations for the Suspended Particulate-Phase 48-Hour Toxicity Tests Using Mytilus galloprovincialis Larvae

Table 16. Replicate and Mean Survival Results and Median Lethal Concentrations for the 96- Hour Acute Suspended Particulate-Phase Toxicity Tests Using Americamysis bahia.

Table 17. Replicate and Mean Survival Results and Median Lethal Concentrations for the 96- Hour Acute Suspended Particulate-Phase Toxicity Tests Using Menidia beryllina. . 50

Table 18. Clam and Polychaete Survival for the Anaheim Bay Harbor Bioaccumulation Exposures

Table 19. Bioaccumulation Potential Tissue Results for Macoma nausuta Exposed to Anaheim Bay Harbor, Reference and Control Sediment Samples

Table 20. Bioaccumulation Potential Tissue Results for Nereis virens Exposed to Anaheim Bay Harbor, Reference and Control Sediment Samples

Table 21. 100% Elutriate SPP Water Column Bioassays Results Table 22. Recommended Placement of Dredged Sediments and Associated Volumes Table 23. Counts of QC records per Chemical Category Table 24. Final QC Qualification Applied to Sample Results v

LIST OF FIGURES

Page No.

Figure 1. Location of Anaheim Bay, Orange County, California Figure 2. Overview of Anaheim Bay Harbor 2017 Dredge Area and Sampling Locations Figure 3. Close-up of Anaheim Bay Harbor 2017 Bathymetry and SAP and Actual Sampling

Locations for the Approach and Entrance Channels Figure 4. Close-up of Anaheim Bay Harbor 2017 Bathymetry and SAP and Actual Sampling

Locations for the Entrance Channel and Portions of the Outer Harbor Figure 5. Close-up of Anaheim Bay Harbor 2017 Bathymetry and SAP and Actual Sampling

Locations for Portions of the Outer Harbor Figure 6. Close-up of Anaheim Bay Harbor 2017 Bathymetry and SAP and Actual Sampling

Locations for the Southern Portion of the Outer Harbor Figure 7. Locations of the Surfside-Sunset Beach Nearshore Placement Area Figure 8. Location of LA-2 Reference Site Figure 9. Distribution of Total PCBs in the Tissues of Macoma and Nereis Figure 10. Sediment Placement Alternatives Based on Physical Compatibility for Areas A and

B Figure 11. Sediment Placement Alternatives Based on Physical Compatibility for Areas B, C1, C2, D1 and D3 Figure 12. Sediment Placement Alternatives Based on Physical Compatibility for Area C3 and

C4 vi

LIST OF ACRONYMS

ASTM American Society for Testing and Materials ND Not Detected

ANOVA Analysis of Variance NOAA National Oceanic and Atmospheric Administration

BLK Method or Procedural Blank NOEC No Observable Effects Concentration

BS Blank Spike NMFS National Marine Fishery Service

BSAF Biota-Sediment Accumulation Factors ODMDS Ocean Dredge Material Disposal Site

BSD Blank Spike Duplicate OTM Ocean Testing Manual

CAD Confined Aquatic Disposal PAH Polycyclic Aromatic Hydrocarbon

CCC Criteria Continuous Concentration PCB Polychlorinated biphenyl

CD Compact Disc PDS Post-Digestion Spike

CDF Confined Disposal Facility PPB Parts Per Billion

CDFW California Department of Fish and Wildlife PPM Parts per Million

CESPD Corps of Engineers South Pacific Division PPT Parts per Thousand

CHHSL California Human Health Screening Level PVC Polyvinyl Chloride

CMC Criteria Maximum Concentration RL Reporting Limit

COC Chain of Custody RBC Risked-Based Concentration

CRM Certified Reference Material ROS Robust Regression on Ordered Statistics

CSTF Contaminated Sediment Task Force RPD Relative Percent Difference

CV Coefficient of Variation SAP Sampling and Analysis Plan

CWA Clean Water Act SAPR Sampling and Analysis Plan Report

DDD Dichlorodiphenyldichloroethane SC-DMMT Southern California Dredge Material Management Team

DDE Dichlorodiphenyldichloroethylene SE Standard Error

DDT Dichlorodiphenyltrichloroethane SET Standard Elutriate Test

DGPS Differential Global Positioning Satellite SOP Standard Operating Procedure

DUP Laboratory Replicates SP Solid Phase

EC50 50% of the Time Effects Concentration SPP Suspended Particulate Phase

ERL Effects Range-Low SRM Standard Reference Material

ERM Effects Range-Medium SURR Surrogate Analysis

ERMq Effects Range-Medium Quotient SWAMP Surface Water Ambient Monitoring Program

HDPE High Density Polyethylene TAC Test Acceptability Criteria

ITM Inland Testing Manual TEQ Toxicity Equivalency Quotient

SARWQCB

Santa Anna Regional Water Quality Control Board

TMDL Total Maximum Daily Load

LC50 50% of the Time Lethal Concentration TOC Total Organic Carbon

LCL Lower Control Limit TRPH Total Recoverable Hydrocarbons

LCS Laboratory Control Spike TRV Toxicity Reference Value

LDPE Low Density Polyethylene TSS Total Suspended Solids

LPC Limiting Permissible Concentration TVS Total Volatile Solids

LSD Least Significant Difference TTL Target Tissue Level

MCL Maximum Contaminant Level UCL Upper Control Limit

MDL Method Detection Limit UCL Upper Confidence Limit

MLLW Mean Lower Low Water USACE U.S. Army Corps of Engineers

MS Matrix Spike USCG U.S. Coast Guard

MSD Matrix Spike Duplicate USEPA U.S. Environmental Protection Agency

NAD North American Datum USFWS U.S. Fish and Wildlife Service

NA Not Applicable QA/QC Quality Assurance/Quality Control

Anaheim Bay Harbor Geotechnical and Environmental Investigation Project

Task Order No. CQ02, USACE, Contract No. W912P7-16-D-0005

1.0 INTRODUCTION

Maintenance dredging is required in the Approach Channel, Entrance Channel and Outer Harbor of Anaheim Bay, California (Figure 1) in order to maintain the channels to their design depths.

Sediments to be dredged require a physical and environmental evaluation of sediment quality in order to support planning and permitting for dredging and reuse. This project was authorized by the Rivers and Harbor Act of 1958 (House Document 362, 83rd Congress, 2nd Session) and (House Document 356, 90th Congress, 2nd Session), pursuant to Section 404 of the Clean Water Act.

This Sampling and Analysis Plan Report (SAPR) has been prepared on behalf of the U.S. Army Corps of Engineers, Los Angeles District to detail procedures and results, including quality assurance/quality control (QA/QC) results, from the sampling and testing of sediments from Anaheim Bay Harbor identified for placement at a nearshore area and/or at the LA-2 Ocean Dredge Material Disposal Site (ODMDS). This work is being performed under Task Order No. QC02, USACE Contract No. W912P7-16-D-0005.

1.1 Project Summary

The purpose of this project is to sample and test sediments from within Anaheim Bay Harbor proposed for maintenance dredging in order to provide sediment quality data for evaluation of dredging and open water placement. This SAPR is to fulfill requirements of CESPD Regulation No. 1110-1-8 (CESPD, 2000), the Ocean Testing Manual (OTM) (USACE and USEPA, 1991), the Inland Testing Manual (ITM) (USACE and USEPA, 1998), the Clean Water Act (CWA), and the Southern California Dredge Material Management Team (SC-DMMT) and Contaminated Sediment Task Force (CSTF) guidelines. Sampling and testing of this project was conducted according to the project Sampling and Analysis Plan (SAP)(Diaz Yourman, GeoPentech and Kinnetic Laboratories JV, 2017) finalized on August 30, 2017.

Project (design) elevations vary throughout the maintenance dredging area. Based on these elevations and a January 2017 hydrographic survey, as much as 343,600 cubic yards (cy) of sediment requires dredging from Anaheim Bay Harbor. This includes the volume for a two foot overdepth allowance. Figure 2 shows an overview of the entire dredge area. Figures 3 through 6 are close-ups showing the 2017 bathymetric data. The proposed project would place all the Anaheim Bay Harbor dredged material in the nearshore area off Surfside-Sunset Beach (Figure 7) provided that physical and chemical properties of the sediments are suitable for this purpose. If some or all of the sediments are determined to be physically incompatible with the nearshore area, then a suitability determination will be sought for placing incompatible material at the LA-2 ODMDS. Project elevations, sampling elevations and dredge volumes for each area identified on

Figures 2 through 6 are provided in Table 1. Project elevations are also shown on Figures 2 through 6

Figure 1. Location of Anaheim Bay, Orange County, California.

Figure 7. Locations of the Surfside-Sunset Beach Nearshore Placement Area.

Table 1. 2017 Dredge Area Project Elevations and Volume Estimates for Anaheim Bay Harbor.

Channel Area Project

Elevation (ft, MLLW)

Project Elevation + Overdepth

(ft, MLLW)

Sampling Elevation*

(ft, MLLW)

Volume to Design Depths (yd3)**

Volume with 2 ft

Overdepth (yd3)**

Approach Channel (Area A1) -39 -41 -41 8,700 30,000 Approach Channel (Area A2) -39 -41 -41 7,500 31,400 Entrance Channel (Area B) -41 -43 -43 58,500 95,300 Outer Harbor Channel (Area C1) -41 -43 -43 62,000 98,100 Outer Harbor Channel (Area C2) -39 -41 -41 2,500 16,900 Outer Harbor Channel (Area C3) -39 -41 -41 15,700 16,600 Outer Harbor Channel (Area C4) -39 -41 -41 200 3,500 Outer Harbor (Area D1) -25 -27 -27 21,700 27,900 Outer Harbor (Area D2) -25 -27 -27 18,200 23,900

TOTALS 195,000 343,600

* Sampling depth includes two feet for overdepth allowance.

**Volume Quantities based on Government survey conducted January 2017.

1.2 Site Location

Anaheim Bay Harbor is located in Orange County, California (Figure 1). Geographic coordinates (NAD 83) for the entrance to the Port are 33 43.6' N and 118 06.1' W. The Surfside-Sunset Beach nearshore placement area is to the southeast of Anaheim Bay, just down coast of the southern breakwater. Geographic coordinates of the approximate center of the nearshore placement area are 33 42.9' N and 118 4.7' W.

1.3 Roles and Responsibilities

Project responsibilities and key contacts for this sediment characterization program are listed in Tables 2 and 3. Kinnetic Laboratories Inc. provided sampling and reporting services. Diaz Yourman and Associates was responsible for core logging and geotechnical testing. Analytical chemical testing of sediments and tissues for this project was primarily carried out by Eurofins Calscience (Cal-ELAP No. 2944). Bioassay and bioaccumulation testing was carried out by Pacific EcoRisk (NELAP No. 04225CA).

The principal users of the data produced by this project are the following Southern California Dredge Material Management Team (DMMT) regulating agencies:

1. Los Angeles District, U.S. Army Corps of Engineers (USACE);

2. Santa Ana Regional Water Quality Control Board (RWQCB)—Region 8;

3. Los Angeles Regional Water Quality Control Board (RWQCB)—Region 4;

4. U.S. Environmental Protection Agency (USEPA) - Region IX; and

5. California Coastal Commission.

Other users of the data may include the following agencies:

1. California Department of Fish and Wildlife (CDFW);

2. U.S. Fish and Wildlife Service (USFWS);

3. U.S. National Marine Fisheries Service (NMFS); and

4. California State Lands Commission (CSLC)

Table 2. Project Team and Responsibilities.

Responsibility Name Affiliation

Project Planning and Coordination

Blake Horita Jeffrey Devine

Steve Estes Christopher Diaz Ken Kronschnabl

USACE

USACE

USACE

Diaz-Yourman Kinnetic Laboratories

Sampling and Analysis Plan (SAP) Preparation Ken Kronschnabl Christopher Diaz

Kinnetic Laboratories Diaz-Yourman

Field Sample Collection and Transport Spencer Johnson

Aidas Worthington Kinnetic Laboratories Kinnetic Laboratories

Geotechnical Investigation Chris Diaz Kelly Shaw

Diaz-Yourman Diaz-Yourman

Health and Safety Officer and Site Safety Plan Jon Toal Kinnetic Laboratories

Laboratory Chemical Analyses Carla Hollowell

Amy Howk Eurofins

Kinnetic Laboratories Biological Testing Jeffrey Cotsifas Pacific EcoRisk

QA/QC Management Analytical Laboratory QA/QC

Danielle Gonsman Amy Howk

Carla Hollowell

Kinnetic Laboratories Kinnetic Laboratories

Eurofins

Technical Review

Pat Kinney Jeffrey Devine

Christopher Diaz Mathew Wesley

Steve Estes

Kinnetic Laboratories

USACE

Diaz-Yourman

USACE

USACE

Final Report Ken Kronschnabl Christopher Diaz

Kinnetic Laboratories Diaz-Yourman

Agency Coordination Jeffrey Devine

Lawrence Smith

USACE

USCAE

Table 3. Key Project Contacts Blake Horita USACE Project Manager PPMD Navigation and Coastal Projects Branch U. S. Army Corps of Engineers, Los Angeles

District 915 Wilshire Blvd.

Los Angeles, Ca. 90017 Tel. (213) 452-3401 Blake.M.Horita@usace.army.mil

Jeffrey Devine USACE Project Technical Manager Geology and Investigations Section U. S. Army Corps of Engineers, Los Angeles District 915 Wilshire Blvd.

Los Angeles, Ca. 90017 Tel. (213) 452-3579 Jeffrey.D.Devine@usace.army.mil

Steve Estes USACE Project Technical Manager U. S. Army Corps of Engineers, Los Angeles District 915 Wilshire Blvd.

Los Angeles, Ca. 90017 Tel. (213) 452-3660

Michele Castro Business Development Manager Eurofins Calscience, Inc.

7440 Lincoln Way Garden Grove, CA 92841-1427 Tel.: (949) 870-8766 MicheleCastro@eurofinsUS.com

Chris Diaz Project Manager - Geotechnical Investigations Diaz Yourman & Associates 1616 East 17th Street Santa Ana, CA 92705-8509 Tel. (714) 245-2920 chris@diazyourman.com

Allen Yourman Joint Venture Project Manager Diaz Yourman Associates, Geopentech, and Kinnetic Laboratories Joint Venture 1616 East 17th Street Santa Ana, CA 92705-8509 Tel. (714) 245-2920 Allen@diazyourman.com

Ken Kronschnabl Project Manager - Sampling/Testing Kinnetic Laboratories, Inc. (KLI) 307 Washington St.

Santa Cruz, CA 95060 Tel. (831) 457-3950 kkronsch@kinneticlabs.com

Amy Howk KLI QA/QC Management Kinnetic Laboratories, Inc.

307 Washington St.

Santa Cruz, CA 95060 Tel. (831) 457-3950 ahowk@kinneticlabs.net

Spencer Johnson Field Operations Mgr.

Kinnetic Laboratories, Inc. (KLI) 307 Washington St.

Santa Cruz, CA 95060 Tel. (831) 457-3950 sjohnson@kinneticlabs.com

2.0 SITE HISTORY AND HISTORICAL DATA REVIEW

This section provides a brief history of Anaheim Bay Harbor, potential sources of contamination, dredging history, and most recent testing and sampling results.

2.1 Site Setting and Potential Sources of Contamination

Anaheim Bay Harbor is located in Orange County adjacent to the City of Seal Beach (Figure 1). The Harbor is divided into inner and outer harbors. The Outer Harbor is protected by 3,500 ft and 4,000 ft east and west jetties built in 1944. The Inner Harbor, protected by up and down coast moles, primarily serves Naval Weapons Station Seal Beach. The Inner Harbor also provides the current entrance to Huntington Harbour and Bolsa Bay to the East and an extensive salt marsh in the Seal Beach National Wildlife Refuge to the North. The Anaheim Bay Harbor facilities are strictly for Navy use. Pleasure craft do transit through the Harbor to private and public berthing facilities throughout Huntington Harbour.

Sediment deposition in Anaheim Bay occurs from flood channels, storm drains, adjacent wetland areas (Bolsa Chica and Seal Beach National Wildlife Refuge), and littoral sediment transport through the Anaheim Bay Harbor entrance. The main flood control channel discharge is from the Bolsa Chica Flood Control Channel that empties into Huntington Harbour. To the south, the Main Channel of Huntington Harbour connects under Warner Avenue and receives flows from Bolsa Bay, the East Garden Grove Wintersburg Channel, and the original Bolsa Chica Wetlands further south. Other potential sources of contamination include local storm water drainages from Seal Beach and Huntington Harbour, which are routed through Anaheim Bay Harbor.

2.2 Previous Anaheim Bay Dredging Episodes

The U.S. Army Corps of Engineers periodically dredges Anaheim Bay Harbor to maintain channel and Harbor design depths. There were four maintenance dredging projects from 1983 through 2009, during which approximately 2,048,000 cy of material was removed. Most of this material (1,398,788 cy) was reused at Surfside-Sunset Beach with 296,447 cy going to the LA-2 ODMDS.

Of the remaining volume of material, 255,050 cy was reused for habitat creation at Seal Beach and 98,096 cy was reused for dike construction. There was one additional dredging episode in 2009.

For this episode, approximately 811,000 cy were dredged. Of this, approximately 301,000 cy was reused for beach nourishment and 510,000 cy was placed at the LA-2 ODMDS.

2.3 Previous Testing Episodes

Three dredge material evaluation studies are discussed below. Two are associated with USACE maintenance dredging and one is associated with U.S. Navy maintenance and construction dredging in support of an Environmental Assessment.

2.3.1 USACE Maintenance Dredging Evaluations

USACE sampled and tested Anaheim Bay Harbor sediments for maintenance dredging in 1999 and 2008. For the 1999 study, a total of five composite samples were formed and analyzed for bulk sediment chemistry. These results are reported by Calscience Environmental Lab (1999) and

Columbia Analytical Services (1999). The 1999 sediment samples contained about 50% sand and were generally low in contaminant concentrations. There were no chemical constituents that exceeded NOAA Effects Range Low (ERL) levels (ERL and ERM values are defined in Section 3.2.6), though reporting limits often exceeded ERL levels. Of the organic contaminants, only phthalates in two samples, PAHs in two samples and PCB congeners in all samples were detected above reporting limits.

Geomatrix sampled Anaheim Bay Harbor sediments along with beach reference sediments in late January and early February of 2008. Bulk sediment physical and chemical testing results from four composite samples of Anaheim Bay sediments are provided in a March 2008 report (Geomatrix, 2008). A summary of the 2008 results are provided in Appendix A. Grain size data from this report suggested that a large portion of the dredge sediments from Anaheim Bay Harbor were not suitable for beach nourishment, though the sediments were generally low in contaminant concentrations. The sediments were described as predominantly silts and lean clay for most areas and silty sand for most of the Approach Channel. The range of fine grain sediment was approximately 43% to 53% in three of the five dredge footprint areas (Approach Channel Area B, Approach Channel Area C and Inner Harbor Area D) sampled. This resulted in these areas being classified as not physically compatible for beach placement at Surfside-Sunset Beach. The three unsuitable areas were instead placed at LA-2 ODMDS. Sediments from the other two footprint areas (Approach Channel Area A, and Outer Harbor Area E) were predominantly coarse grained and compatible for placement at Surfside-Sunset Beach. The total volume of material placed at Surfside-Sunset Beach was approximately 140,000 cy.

Chemically, the Geomatrix (2008) report showed that all sediment metals were reported below ERL values and most organic constituents were not detected in the Harbor sediments. DDE was present in all four composite samples above the ERL level. The only other organic contaminants detected in the Harbor sediments were low levels of several PAH compounds. Total PAHs were well below the ERL level. The generally clean sediments were verified by low Effects Range Median (ERM) quotients (see Section 3.2.6).

Since the Geomatrix (2008) report concluded that much of the Anaheim Bay Harbor sediments were not physically compatible for beach nourishment, a subsequent Tier III investigation was undertaken in all areas but one area in the Approach Channel to supplement the Geomatrix data and evaluate the suitability for placing the sediments at the LA-2 ODMDS. To collect the material for Tier III testing, vibracore borings were advanced to project depths plus four feet at sixteen (16) locations within Anaheim Bay Harbor. Sediments from these borings, down to project depths plus two feet, were combined to form three composite samples for Tier III testing. Tier III testing included water column bioassays with bivalve larvae, mysids and fish, benthic bioassays with amphipods and worms, and bioaccumulation potential with clams and worms. A second layer from two to four feet below project depths was also sampled and composited into three samples in order to characterize sediments that may inadvertently be dredged below the allowable overdredge depth. These samples were analyzed for chemical constituents only. Following ITM and OTM guidelines (USEPA/USACE, 1991 and 1998), results of the upper test sediments were compared to LA-2 reference sediments in the vicinity of the open water disposal site.

The results of the 2009 Tier III investigation are summarized in a report by Kinnetic Laboratories and Diaz Yourman and Associates (2009). Summary data are also provided in Appendix B. The report concluded that the Anaheim Bay Harbor sediments should be acceptable for placement at the LA-2 ODMDS based on the following results:

Tier III water column bioassays for all composite samples showed that initial dilutions would remove all observed toxicity and Limiting Permissible Concentrations (LPCs) were not exceeded.

Tier III benthic bioassays showed no statistically significant amphipod and polychaete toxicity with the exception of polychaete worms exposed to one composite sample. Other data, including clean sediment chemistry results and excellent performance of the same sediments in the long-term polychaete bioaccumulation exposures, indicate that this single observed toxicity was most likely an anomaly.

Bioaccumulation results showed significant but only minor bioaccumulation of a few metals and PAH compounds in the test tissues of clams and worms.

Chemical analyses of the two-foot layer below the overdepth sampled in 2009 are summarized in Appendix C. The results showed generally low levels of inorganic and organic constituents with exception of elevated 4,4'-DDE and total DDT concentrations, which were similar to or exceeded NOAA ERM values.

2.3.2 U.S. Navy Maintenance and Construction Dredging Evaluation

The U.S. Navy sanctioned the most recent dredge material characterization study for Anaheim Bay Harbor in 2016 (Tierra Data, 2016). This study was carried out to evaluate sediments for maintenance dredging in portions of the Inner and Outer Harbor not being evaluated under this current study by USACE and to evaluate dredge sediments associated with the construction of a new ammunition pier, reconfiguration of the Turning Basin, and construction of a separate private boat channel through the South Mole. Sediments to be dredged as part of this study were evaluated for a variety of beneficial reuses including beach nourishment, shallow water habitat creation and construction fill. Some sediments were also evaluated for potential placement at the LA-2 ODMDS. A total of 62 locations were sampled and combined into 14 composite samples for physical and chemical testing. Ten composite samples were associated with construction dredging and four composite samples were associated with maintenance dredging. Except for locations associated with the construction of a private boat channel, all locations were sampled down to an elevation of -39 feet MLLW plus two feet for overdepth allowance. The 16 private boat channel locations were sampled down to -20 feet MLLW plus two feet for overdepth allowance.

The Tierra Data (2016) report is provided in Appendix D. Sediment concentrations were generally low in the composite samples. For the construction dredging composite samples, copper and total PCBs in one composite sample, 4,4'-DDE in three composite samples, and total DDT four composite samples were the only analytes to exceed ERL values. For the four maintenance dredging composite samples, nickel and zinc in one composite sample, 4,4'-DDE in three composite samples and total DDT in all four composite samples exceeded corresponding ERL values. Also worth mentioning is that dibutyltin was present above the reporting limit in seven of the ten construction dredging composite samples and all four maintenance dredging composite samples, and the pyrethroid pesticides bifenthrin and cyfluthrin were present above reporting limits in the maintenance dredging composite samples.

The Tierra Data (2016) report made suitability recommendations based primarily on grain size characteristics. The report indicated that all composite areas would be suitable for habitat creation and as fill material. The report also indicated that six out of the ten construction dredging composite areas were suitable for beach nourishment with greater than 80% sand content. None of the maintenance dredging composite samples were suitable for beach nourishment since the fines content for these composite samples were all greater than 97%.

Three of the construction dredging composite samples not suitable for beach nourishment were further tested and evaluated for placement at the LA-2 ODMDS. OTM Tier III testing was conducted on these composite samples. The Tierra Data report indicated that there was no solid phase toxicity in the test sediments to amphipods and polychaetes and calculated LC50 and EC50 values for the water column bioassays were all greater than 100% elutriate. Twenty-eight-day bioaccumulation potential was evaluated on two of the composite samples for copper and PCBs.

Mean tissue copper and PCB residue levels after exposures to the composite samples were less than mean PCB and copper residue levels in the LA-2 reference tissues. The report recommends that the composite areas evaluated for ocean disposal were suitable for placement at the LA-2

ODMDS.

3.0 METHODS

This section describes the dredging design, study design and field and analytical methods for this testing program.

3.1 Dredge Design

Bathymetric data from January 2017 in relationship to target sampling locations are shown on Figures 2 through 6. Figures 2 through 6 also defines the limits of dredging. Design depths and dredge volumes for each area identified for dredging are provided in Table 1.

3.2 Sampling and Testing Design

The sampling and testing design detailed in the SAP for this project and summarized below covered data collection tasks for Anaheim Bay Harbor sediment and water collection and testing, Surfside-Sunset Beach nearshore area sediment collection and testing, and the LA-2 reference area sediment collection and testing. Evaluation guidelines are also discussed below.

The main approach for the Anaheim Bay Harbor sediments was to sample the sediments to dredge depths plus two feet for overdepth allowance, composite sediments together by area, and subject the composite samples to chemical and biological testing to determine if the Anaheim Bay Harbor maintenance dredging sediments are suitable for nearshore area placement and/or placement at the LA-2 ODMDS. The approach was also to determine the physical properties of the sediments at each location and at different depths. Testing followed requirements and procedures detailed in the OTM (USACE/USEPA, 1991), the ITM (USEPA/USACE, 1998) with further guidance from Los Angeles District USACE guidelines (CESPL, undated) and from SC-DMMT draft guidelines.

Acceptability guidelines published in these documents and other sources were used to evaluate the suitability of Anaheim Bay Harbor dredged sediments for open water placement.

3.2.1 Anaheim Bay Harbor Sample Identification, Sediment Collection and Composite

Formation

The project SAP initially called for eleven core locations and the testing of one (1) composite sample. However, the SC-DMMT agencies requested that the number of core locations be increased to 17 and the number of composite samples be increased to four (4) during the June 2017 SC-DMMT meeting. The project SAP was revised and discussed again during the July SC-DMMT meeting. During this meeting, the USEPA requested two additional core locations be added to the testing program bringing the toal number of core locations to 19.

Based on the final, approved SAP. vibracore sampling, as described in Section 3.3.2 (Vibracore Sampling Methods), was carried out to collect subsurface sediment data from the Approach Channel (Area A), Entrance Channel (Area B), Outer Harbor Channel (Area C) and from other shoaled areas in the Outer Harbor (Area D) not previously characterized by the U.S. Navy in 2016.

Except for Area C, four (4) locations were sampled in each area. Seven (7) locations were sampled in Area C. The prefix used for all vibracore locations was “ANHVC-17-#-##.” All cores were collected on August 22 and 23, 2017. Final as well as the SAP sampling locations are shown on Figures 2 through 6. All cores were advanced beyond the two foot below overdepth elevations.

Geographic coordinates, time of sampling, seafloor elevations, target elevations, and sampling intervals for the final sample locations are listed in Table 4. Note that a few sample locations changed slightly from the proposed locations to target more shoaled areas.

One composite sample was created from each of the four major channel areas (A, B, C and D).

These composite samples were analyzed for bulk sediment chemistry and tested for benthic and water column toxicity and bioaccumulation potential. Except for water column toxicity testing, a sample of LA-2 reference material underwent the same testing. Continuous samples from the mudline to project depths plus two feet for overdepth testing (-41 feet MLLW for Areas A1, A2, C2 and C3, -43 feet MLLW for Areas B and C1, and -27 feet MLLW for Area D1 and D2) were collected from all core locations. These primary core intervals were homogenized and then combined with the primary core intervals from all other cores within a composite area to form the area composite samples. Sediments collected below the overdepth elevations were not included in the sediment composite samples.

In addition to the composite samples, an archive bulk sediment chemistry sample was collected from each core location. These archive samples represent the entire primary core interval (mudline to overdepth elevations). All archive samples are being stored frozen for at least six months unless directed otherwise by the USACE Technical Manager.

Core subsamples for geotechnical testing were from any geologically distinct layer between the mudline and overdepth elevation that was six inches or greater in length. Data from all geotechnical samples collected were used to determine which sediments within the entire maintenance dredging area can be beneficially reused by placing them in the nearshore area of Surfside-Sunset Beach.

3.2.2 Reference Sediment Collection

A series of random surface grabs were collected within the nearshore area off of Surfside-Sunset Beach identified on Figure 7. Individual geotechnical grain size testing was performed on all grab samples collected within the nearshore area. These samples are identified as SSBNS-17-01 through SSBNS-17-11, and the final coordinates, sampling times and water depths are provided in Table 5.

Surface sediments was also collected from the LA-2 reference area on August 18, 2017 and used as reference material for the OTM Tier II and III testing to assess suitability for open water placement of the dredged materials. The sample was collected around 10:30 AM in 625 to 650 feet of water. Approximate geographic coordinates of the sample collected were 33º 33.2ʹ and -118º 10.8ʹ.

Table 4. Actual Sampling Location Coordinates, Date and Time of Sampling, Core Depths, Mudline Elevations, and Sampling Elevations for the 2017 Anaheim Bay Harbor Sampling and Testing Program.

Fed.

Chan./ Area

Core Designation Date

Sampled Time

Sampled

California Lambert Zone 6 (NAD 83)

Geographic Coordinates (NAD 83) Mudline

Elevation (ft., MLLW)

Design Depth +

Overdepth (ft., MLLW)

Core Recovery

(ft.)

Core Interval Sampled

(ft., MLLW) Northing

(feet) Easting (feet)

Latitude North

Longitude West

A rea A pproach C hannel

ABHVC-17-A-01 8/22/17 0845 2211234 5996985 33° 43.298ʹ 118° 06.428ʹ -38.3 -41 8.0 -38.3 to -41

ABHVC-17-A-02 8/22/17 0945 2210984 5997700 33° 43.259ʹ 118° 06.286ʹ -38.0 -41 6.5 -38.0 to -41

ABHVC-17-A-03 8/22/17 1035 2211752 5998180 33° 43.387ʹ 118° 06.194ʹ -37.5 -41 9.0 -37.5 to -41

ABHVC-17-A-04 8/22/17 1110 2212417 5997999 33° 43.496ʹ 118° 06.232ʹ -37.2 -41 7.6 -37.2 to -41 rea B

E ntrance C hannel

ABHVC-17-B-01 8/23/17 0734 2212660 5998297 33° 43.537ʹ 118° 06.174ʹ -38.7 -43 9.5 -38.7 to -43

ABHVC-17-B-02 8/23/17 0820 2212431 5998552 33° 43.500ʹ 118° 06.123ʹ -38.5 -43 9.3 -38.5 to -43

ABHVC-17-B-03 8/23/17 0900 2212820 5998503 33° 43.564ʹ 118° 06.134ʹ -39.3 -43 9.3 -39.3 to -43

ABHVC-17-B-04 8/23/17 0945 2213223 5999052 33° 43.632ʹ 118° 06.027ʹ -39.4 -43 8.1 -39.4 to -43 rea C

O uter H arbor

C hannel

ABHVC-17-C-01 8/22/17 1225 2213616 5999110 33° 43.697ʹ 118° 06.017ʹ -37.8 -43 8.0 -37.8 to -43

ABHVC-17-C-02 8/22/17 1327 2213705 5999568 33° 43.713ʹ 118° 05.927ʹ -37.1 -43 8.7 -37.1 to -43

ABHVC-17-C-03 8/22/17 1430 2214207 5999633 33° 43.796ʹ 118° 05.916ʹ -37.4 -41 7.8 -37.4 to -43

ABHVC-17-C-04 8/22/17 1505 2214207 5999987 33° 43.797ʹ 118° 05.846ʹ -37.9 -41 9.0 -37.9 to -41

ABHVC-17-C-05 8/22/17 1813 2215261 6000781 33° 43.973ʹ 118° 05.693ʹ -34.7 -41 8.0 -34.4 to -41

ABHVC-17-C-06 8/22/17 1255 2213346 5999308 33° 43.653ʹ 118° 05.977ʹ -37.2 -43 8.4 -37.2 to -43

ABHVC-17-C-07 8/22/17 1400 2214065 5999473 33° 43.772ʹ 118° 05.947ʹ -38.2 -43 7.8 -38.2 to -43 rea D

O uter H arbor

ABHVC-17-D-01 8/22/17 1627 2213394 5999694 33° 43.662ʹ 118° 05.901ʹ -19.0 -27 9.2 -19.0 to -27

ABHVC-17-D-02 8/22/17 1550 2213632 6000291 33° 43.703ʹ 118° 05.784ʹ -18.6 -27 9.4 -18.6 to -27

ABHVC-17-D-03 8/22/17 1725 2213833 5998871 33° 43.732ʹ 118° 06.065ʹ -20.9 -27 7.3 -20.9 to -27

ABHVC-17-D-04 8/22/17 1745 2214281 5998919 33° 43.806ʹ 118° 06.057ʹ -19.5 -27 9.5 -19.5 to -27

Table 5. Date, Times and Sampling Coordinates for Samples Collected from the Surfside Subset Beach Nearshore Placement Area.

Area Site

Designations Date Time

Approx.

Sampling Elevations

(feet, MLLW)

Geographic Coordinates

(NAD 83)

Latitude North

Longitude West

Surfside- Sunset Beach

Nearshore Placement

Area

SSBNS-17-01 8/21/17 1103 26.51 33° 42.9303ʹ 118° 04.7169ʹ

SSBNS-17-02 8/21/17 1110 25.00 33° 42.9664ʹ 118° 04.6760ʹ

SSBNS-17-03 8/21/17 1119 18.00 33° 42.9871ʹ 118° 04.6169ʹ

SSBNS-17-04 8/21/17 1121 18.00 33° 42.9400ʹ 118° 04.5609ʹ

SSBNS-17-05 8/21/17 1125 21.00 33° 42.9066ʹ 118° 04.5990ʹ

SSBNS-17-06 8/21/17 1128 22.00 33° 42.8489ʹ 118° 04.6205ʹ

SSBNS-17-07 8/21/17 1132 20.00 33° 42.8474ʹ 118° 04.5520ʹ

SSBNS-17-08 8/21/17 1137 18.00 33° 42.8528ʹ 118° 04.4811ʹ

SSBNS-17-09 8/21/17 1141 22.00 33° 42.7703ʹ 118° 04.4653ʹ

SSBNS-17-10 8/21/17 1152 22.00 33° 42.6829ʹ 118° 04.4583ʹ

SSBNS-17-11 8/21/17 1152 19.00 33° 42.7575ʹ 118° 04.3775ʹ

3.2.3 Environmental Testing

Bulk sediment analyses performed on the Anaheim Bay Harbor composite samples and the LA-2 reference sample were as follows:

Metals including mercury (10 total) Percent solids Total ammonia Total volatile solids (TVS) Oil and grease Total recoverable petroleum hydrocarbons (TRPH)

TOC

Butyltins Chlorinated pesticides Pyrethroid Pesticides Polychlorinated biphenyl (PCB) congeners (41 total) Phenols Phthalate esters Polycyclic aromatic hydrocarbons (PAHs)

To fully evaluate sediments for open water placement, the composite samples required the following additional Tier III testing:

Whole sediment bioassays using amphipods and polychaete worms.

Water column suspended particulate phase (SPP) bioassays using mysids, juvenile teleost fish, and bivalve larvae.

Bioaccumulation exposures using clams and polychaete worms.

Tissue analyses for DDT compounds and lipids.

Except for the SPP bioassays, these same tests were performed on a sample collected from the LA- 2 reference area.

3.2.4 Geotechnical Samples and Testing

A sufficient quantity of sediment was collected from each location within the Anaheim Bay Harbor maintenance dredging areas so that a representative amount of sediment was included in each geotechnical sample. At least one primary grain size sample was formed and analyzed from each core between the mudline and the overdepth elevations. Additional grain size samples representing layers of physically different material greater than six inches were also collected. Grain size analyses were also run on each of the 11 locations from the Surfside-Sunset Beach nearshore area.

In addition to the mechanical grain size samples, six (6) hydrometer tests and four (4) Atterberg Limits tests were run. The hydrometer and Atterberg tests were run on representative samples of fine grained material collected from the sediment cores.

All geotechnical data gathered was used to do physical beach compatibility analyses between the dredged sediments and the receiving beach. This task was accomplished by USACE-Los Angeles District and is included as Appendix E to this report.

3.2.5 Summary of Anaheim Bay Harbor Testing and Evaluation Sequence

The testing and evaluation sequence for the Anaheim Bay Harbor composite sample is described in detail in the next subsection and is outlined as follows:

1) Bulk sediment chemical analyses were conducted on the composite samples.

2) Grain size physical compatibility analyses were conducted by the Los Angeles District U.S.

Army Corps of Engineers Geotechnical Branch.

3) Analytical results were evaluated using the sediment quality guidelines consisting of

Effects Range Low (ERL) and Effects Range Medium (ERM) values developed by Long, et al. (1995) that correlate concentrations of selected contaminants with likelihood of adverse biological effects. The sediment chemistry summary tables in Section 4 (Results) list available ERL and ERM values. Please note that ERLs and ERMs have not been developed for all analytes.

4) Analytical results were also evaluated using the USEPA’s RSL (Regional Screening Levels) (USEPA Region 9, updated 2017) and the State of California’s CHHSL (California Human Health Screening Levels) for potential effects to humans (Cal/EPA, updated 2010). The sediment chemical summary table in Section 4 lists the available RSL and CHHSL values.

5) All bioassays and tissue analyses completed were evaluated to determine if the sediments exceeded OTM and USEPA Region 9 criteria for open water placement.

If grain size characteristics are compatible with the beach nearshore area, contaminant levels are low compared to effects based screening levels and human health screening levels, and the sediments are not toxic to benthic organisms, then the sediments should be suitable for nearshore placement. If the sediments are not physically compatible with the receiving beach, contaminant levels are low, the sediments are not toxic to benthic and water column species, and the bioaccumulation potential of contaminants of concern is low, then the sediments should be suitable for open water placement.

3.2.6 Evaluation Guidelines

As mentioned above, to aid in the evaluation of sediment test data, chemical concentrations of contaminants found within the sediments were compared to sediment quality guidelines (Long et.

al., 1995) developed by NOAA. These guidelines are generally used to screen sediments for contaminant concentrations that might cause biological effects and to identify sediments for further toxicity testing. For any given contaminant, ERL guidelines represent the 10th percentile concentration value in the NOAA database that might be expected to cause adverse biological effects and ERM guidelines reflect the 50th percentile value in the database.

As an additional measure of potential toxicity, the mean ERM quotient (ERMq) for the composite samples were evaluated according to Long et al. (1998a) and Hyland et al. (1999). ERMq is calculated by dividing each contaminant concentration by its respective ERM value and then summing the results and dividing through by the number of contaminants as shown in the following equation:

ERM

entrationSampleConctERMQuotien 24

In cases where concentrations of measured contaminants were below the method detection limit (MDL), a value of ½ the MDL was used for the ERMq calculations. For a general overall indication of toxicity, a quotient less than 0.1 is indicative of a low probability (<12%) of a highly toxic response to marine amphipods (Long and MacDonald, 1998b). If there are no ERL exceedances in a sample, there is less than a 10% probability of a highly toxic response to marine amphipods. The probability of a highly toxic response increases to 71% for quotients greater than 1.0.

The dredge materials were also assessed to whether or not they are suitable for human contact. To do so, the chemical results were compared to “Regional Screening Levels for Chemical Contaminants at Superfund Sites" (USEPA Region 9, updated 2017), formerly known as Preliminary Remediation Goals (PRGs). These screening levels (RSLs) were developed for Superfund/RCRA programs and are a consortium of USEPA Region 9 Preliminary Remediation Goals (PRGs), USEPA Region 3 Risked-Based Concentrations (RBCs) and EPA Region 6 Human Health Medium – Specific Screening Levels (HHMSSLs). RSLs are risk-based concentrations derived from standardized equations combining exposure information assumptions with EPA toxicity data. They are usually updated on an annual basis. RSLs used for this study are based on a target hazard quotient of 0.1.

Human health risks from the sediments were further evaluated using California Human Health Screening Levels (CHHSLs). CHHSLs (Cal/EPA, updated 2010) are concentrations of 54 hazardous chemicals in soil or soil gas that are considered to be protective of human health. The CHHSLs were developed by the Office of Environmental Health Hazard Assessment (OEHHA) on behalf of California Environmental Protection Agency (Cal/EPA). CHHSLs were developed using standard exposure assumptions and chemical toxicity values published by the USEPA and

Cal/EPA. CHHSL values used were developed separately for industrial/commercial settings and for residential settings.

SPP bioassays using mysids, fish and the larvae of mussels were conducted on the sediment composite samples in order to evaluate water quality effects due to dumping of the sediments through the water column at the LA-2 ODMDS. Standard elutriates were prepared with site water, and water used to make the dilutions was from a clean open-coast source. Concurrent bioassays were performed on 100%, 50%, 10% and 1% elutriate concentrations and laboratory control water.

Results of elutriate bioassays were statistically compared with control water bioassays. Elutriate extracts that produced significantly greater toxicity than control water, if any, were identified.

OTM guidelines for interpretation of suspended particulate-phase bioassays require that initial mixing calculations be performed to determine the concentration of liquid and suspended particulate material at edge of the mixing zone after dumping and within the mixing zone four hours after dumping for any sample producing toxicity sufficient to generate an LC50 or EC50. The statistical calculations to determine LC50s and EC50s are through interpolations. If the concentration at the edge of the mixing zone or within the mixing zone four hours after dumping does not exceed 1% of the LC50 or EC50, the sediment is judged to comply with water column toxicity criteria.

Solid phase (SP or benthic) bioassays were also conducted for ocean placement using polychaete worms and amphipods. Benthic bioassay results were statistically compared with bioassay results from reference sediments collected in the vicinity of LA-2 ODMDS and with control sediments collected from the organisms’ home environment. Guidelines for interpretation of benthic bioassay results are published in the OTM. If survival responses in test sediment are statistically lower than those in reference sediment and if the difference in mean survival between groups is greater than 10% (20% for amphipods), then the test sediment is considered to have the potential to significantly degrade the marine environment.

Twenty-eight-day bioaccumulation exposures were performed on the composite samples.

Composite sediment exposures were run concurrently with exposures to LA-2 reference and control sediments.

The final phase of testing for open water placement was accomplished by…