AppJ_Remedial Action Plan and Design Report by Anchor.pdf

APPENDIX J

REMEDIAL ACTION PLAN AND DESIGN REPORT, IR SITE 7

(WEST BASIN) DREDGING PROJECT, PORT OF LONG BEACH,

CA, DATED APRIL 2009 BY ANCHOR ENVIRONMENTAL, LLC

REMEDIAL DESIGN AND REMEDIAL ACTION WORK PLAN

IR SITE 7 (WEST BASIN) DREDGING PROJECT

PORT OF LONG BEACH, CALIFORNIA

Prepared for

The!Port!of!Long!Beach!

925!Harbor!Plaza!

Long!Beach,!California!!90802!

Prepared by

Anchor!Environmental!CA,!L.P.!

28202!Cabot!Road,!Suite!425!

Laguna!Niguel,!California!!92677!

April 2009

Table of Contents

Remedial!Design!and!Remedial!Action!Work!Plan! ! April!2009!

IR!Site!7!(West!Basin)!Dredging!Project! i! 060343"01!

1! INTRODUCTION!................................................................................................................................!1!

1.1! Project!Description!and!History!...............................................................................................!1!

1.2! Cleanup!Areas!and!Anticipated!Remedial!Actions!..............................................................!3!

1.3! General!Description!of!Remedial!Action!................................................................................!7!

1.3.1! AOEC"A!and!AOEC"C!........................................................................................................!7!

1.3.2! AOEC"E!.................................................................................................................................!8!

1.3.3! AOEC"F!and!AOEC"G!.........................................................................................................!8!

1.4! Applicable!or!Relevant!and!Appropriate!Requirements!......................................................!9!

2! EXISTING!CONDITIONS!................................................................................................................!11!

2.1! Physical!and!Chemical!Conditions!........................................................................................!11!

2.2! Surrounding!Land!Use!............................................................................................................!13!

2.3! Hydraulic!Conditions!..............................................................................................................!13!

2.4! Geotechnical!and!Structural!Conditions!...............................................................................!14!

2.5! Potential!for!Site!Recontamination!........................................................................................!15!

3! DREDGE!AND!DISPOSAL!PLAN!..................................................................................................!16!

3.1! Anticipated!Equipment!and!Assumptions!...........................................................................!17!

3.1.1! Production!...........................................................................................................................!17!

3.1.2! Dredging!Limits!.................................................................................................................!19!

3.1.3! Placement!of!Sediment!Within!the!Pier!G!Slip!Fill!Site!................................................!19!

4! CONSTRUCTION!SCHEDULE!AND!SEQUENCING!................................................................!21!

5! POTENTIAL!CONSTRUCTION!IMPACTS!AND!BEST!MANAGEMENT!PRACTICES!.......!23!

5.1! Effects!of!Resuspended!Sediments!Due!to!Dredging!Impacts!..........................................!23!

5.2! Potential!Short"term!Water!Quality!Impacts!........................................................................!24!

5.2.1! Water!Quality!Impacts!at!Point!of!Dredging!.................................................................!25!

5.2.2! DREDGE!Model!Input!......................................................................................................!25!

5.2.3! DREDGE!Model!Results!...................................................................................................!27!

5.2.4! Prediction!of!Water!Quality!Impacts!at!Point!of!Disposal!...........................................!28!

5.2.5! Prediction!of!Spread!of!Placed!Sediment!.......................................................................!29!

5.2.6! STFATE!Model!Input!........................................................................................................!30!

5.2.7! STFATE!Modeling!Results!................................................................................................!30!

5.2.8! Rehandling!over!the!Containment!Berm!........................................................................!34!

5.2.9! Dredge!Residual!Management!........................................................................................!35!

5.2.10! Post"dredge!Residual!Expectations!.................................................................................!35!

5.2.11! West!Basin!Residual!Analysis!Results!............................................................................!36!

5.3! Contractor!Controls!and!Best!Management!Practices!........................................................!37!

5.3.1! Operational!Controls!.........................................................................................................!37!

5.3.2! Specialized!Equipment!......................................................................................................!38!

5.3.3! Water!Quality!Monitoring!................................................................................................!38!

5.3.4! Post"dredge!Monitoring!....................................................................................................!39!

IR!Site!7!(West!Basin)!Dredging!Project! ii! 060343"01!

5.3.5! Management!of!Dredging!Residuals!..............................................................................!40!

5.4! Long"term!Effectiveness!of!Disposal!Location!.....................................................................!40!

5.4.1! Model!Inputs!and!Assumptions!......................................................................................!41!

5.4.2! Model!Results!.....................................................................................................................!43!

6! CONTINGENCY!MEASURES!.........................................................................................................!44!

6.1! Confirmation!of!Sufficient!Sediment!Removal!....................................................................!44!

6.2! Contingency!Actions!for!Short"term!Water!Quality!...........................................................!45!

7! CONCLUSIONS!................................................................................................................................!46!

8! REFERENCES!....................................................................................................................................!47!

List of Tables

Table!1"1!! West!Basin!Sediment!Management!Objectives

Table!2"1!! Summary!of!Total!Solids!and!Metals!in!AOEC"A!01!and!AOEC"A!02!and!a!

Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"2!! Summary!of!Total!Solids!and!Metals!in!AOEC"A!03!and!AOEC"A!04!and!a!

Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"3!! Summary!of!Total!Solids!and!Metals!in!AOEC"A!05!and!AOEC"A!06!and!a!

Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"4!! Summary!of!Total!Solids!and!Metals!in!AOEC"A!07!and!AOEC"C!East!01!and!a!

Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"5!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!East!02!and!AOEC"C!East!03!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"6!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!East!04!and!AOEC"C!East!05!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"7! Summary!of!Total!Solids!and!Metals!in!AOEC"C!East!06!and!AOEC"C!East!07!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

IR!Site!7!(West!Basin)!Dredging!Project! iii! 060343"01!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"8! Summary!of!Total!Solids!and!Metals!in!AOEC"C!East!08!and!AOEC"C!East!09!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"9!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!West!01!and!AOEC"C!West!02!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"10!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!West!03!and!AOEC"C!West!04!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"11!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!West!05!and!AOEC"C!West!06!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"12!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!West!07!and!AOEC"C!West!08!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"13!! Summary!of!Total!Solids!and!Metals!in!AOEC"C!West!09!and!AOEC"C!West!10!

and!a!Comparison!to!Published!Effects!Range!Low!and!Effects!Range!Median!

Sediment!Quality!Values,!Long!Beach!Naval!Station!Sediment!Management!

Objectives,!and!Total!Threshold!Limit!Concentration!Regulatory!Levels

Table!2"14!! IR!Site!7!–!West!Basin!Soluble!Threshold!Limit!Concentrations!Chemistry!Results

Table!3"1!! Estimated!Dredge!Sediment!Volumes

Table!5"1!! Summary!of!Physical!and!Chemical!Analysis!of!IR!Site!7!Project!Sediment!

Elutriates!and!Site!Water!and!a!Comparison!to!California!Ocean!Plan!Water!

Quality!Objections

Table!5"2! !Input!Parameters!Used!in!DREDGE!Modeling

Table!5"3!! Key!Input!Parameters!Used!in!STFATE!Modeling

Table!5"4!! Estimated!Residual!Layer!Thickness

Table!5"5!! Sediment!Management!Objective!Limits!and!Calculated!95!Percent!Upper!

Confidence!Limits

Table!5"6!! Summary!of!Physical!Input!Parameters!for!Chemical!Isolation!Modeling

Table!5"7!! Summary!of!Chemical!Input!Parameters!for!Chemical!Isolation!Modeling

Table!5"8!! Summary!of!Chemical!Isolation!Layer!Modeling!Steady"state!Results!Under!!

Nominal!Seepage!Velocity!Scenario

IR!Site!7!(West!Basin)!Dredging!Project! iv! 060343"01!

List of Figures

Figure!1"1! Project!Vicinity!Map!

Figure!1"2! Project!Location!and!Overall!Site!Plan!

Figure!2"1! Weston!2007!Sediment!Sampling!Locations!

Figure!3"1! Plan!–!Typical!Dredging!Plan!View!for!AOEC"C!West!(Draft)!!

Figure!3"2! Section!–!Typical!Dredging!Cross!Section!for!AOEC"A!(Draft)!

Figure!3"3! Section!–!North!Slip!Fill!Closure!Dike!

Figure!5"1! Comparison!of!Total!Suspended!Sediment!Data!Reported!for!Various!Dredging!

Operations!to!Potential!Effects!Levels!Reported!for!a!Variety!of!Marine!and!

Estuarine!Species!

Figure!5"2! AOEC"A!at!48!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"3! AOEC"A!at!55!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"4! AOEC"C!East!45!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"5! AOEC"C!East!at!48!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"6! AOEC"C!West!at!35!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"7! AOEC"C!West!at!49!Feet!Depth!Total!Suspended!Solids!as!Predicted!by!DREDGE!

Figure!5"8! Total!Deposited!Material!Thickness!as!a!Function!of!Distance!from!Dump!

Location!for!AOEC"A!

Figure!5"9! Total!Deposited!Material!Thickness!as!a!Function!of!Distance!from!Dump!

Location!for!AOEC"C!West!

Figure!5"10! Concentration!of!Total!Suspended!Solids!as!a!Function!of!Distance!from!Dump!

Location!for!AOEC"A!

Figure!5"11! Concentration!of!Total!Suspended!Solids!as!a!Function!of!Distance!from!Dump!

Location!for!AOEC"C!West!

List of Appendices

Appendix!A! Draft!Construction!Plans!for!Dredging!of!West!Basin!(Provided!on!CD)!!!

Prepared!by!KPFF!Consulting!Engineers!

Appendix!B! Draft!Construction!Plans!for!the!Development!of!the!Pier!G!Slip!Fill!Site!

(Provided!on!CD)!!Prepared!by!Moffatt!and!Nichol!

Appendix!C! Review!and!Description!of!Best!Management!Practices!

Appendix!D! Expected!Water!Quality!Monitoring!Requirements!

Appendix!E! Development!of!Confirmatory!Sampling!Plan!

Appendix!F! Response!to!Comments!

Acronyms and Abbreviations

IR!Site!7!(West!Basin)!Dredging!Project! v! 060343"01!

ADDAMS! Automated!Dredging!Disposal!and!Alternatives!Modeling!System!

AOEC! ! Area!of!Ecological!Concern!

ARARS! Applicable!or!Relevant!and!Appropriate!Requirement!

BMP! ! best!management!practice!

BRAC! ! Base!Re"alignment!and!Closure!

CalEPA! California!Environmental!Protection!Agency!

CCR! ! California!Code!of!Regulations!

CEQA! ! California!Environmental!Quality!Act!

CERCLA! Comprehensive!Environmental!Response,!Compensation,!and!Liability!Act!

CFR! ! Code!of!Federal!Regulations!

City! ! City!of!Long!Beach!

CSTF! ! Contaminated!Sediments!Task!Force!

COEC! ! Chemical!of!Ecological!Concern!

cy! ! cubic!yard!

DDT! ! dichloro!diphenyl!trichloroethane!

DTSC! ! Department!of!Toxic!Substances!Control!

ERL! ! Effects!Range!Low!

ERM! ! Effects!Range!Median!

FS! ! Feasibility!Study!

GPS! ! global!positioning!system!

HQ! ! hazard!quotient!

IC! ! institutional!control!

IR! ! Installation!Restoration!

KPFF! ! KPFF!Consulting!Engineers!

LARWQCB! Los!Angeles!Regional!Water!Quality!Control!Board!

LBNC! ! Long!Beach!Naval!Complex!

LBNS! ! Long!Beach!Naval!Shipyard!

LIFOC!! Lease!in!Furtherance!of!Conveyance!

mg/L! ! milligram!per!liter!

MLLW!! mean!lower!low!water!

MND! ! Mitigated!Negative!Declaration!

NAVSTA! Naval!Station!Long!Beach!

NCP! ! National!Contingency!Plan!

Acronyms and Abbreviations

IR!Site!7!(West!Basin)!Dredging!Project! vi! 060343"01!

PAH! ! polycyclic!aromatic!hydrocarbon!

PCB! ! polychlorinated!biphenyl!

Port! ! Port!of!Long!Beach!

RAO! ! Remedial!Action!Objective!

RI! ! Remedial!Investigation!

ROD! ! Record!of!Decision!!

SET! ! Standard!Elutriate!Test!

SMO! ! Sediment!Management!Objective!

STLC! ! Soluble!Threshold!Limit!Concentration!

TOC! ! total!organic!carbon!

TSS! ! total!suspended!solids!

TTLC! ! Total!Threshold!Limit!Concentration!

UCL! ! Upper!Confidence!Limit!

USACE! U.S.!Army!Corps!of!Engineers!

USEPA! U.S.!Environmental!Protection!Agency!

Weston! Weston!Solutions,!Inc.!

WDR! ! Waste!Discharge!Requirement!

Introduction!

IR!Site!7!(West!Basin)!Dredging!Project! 1! 060343"01!

1 INTRODUCTION

This!report!describes!remedial!design!elements!and!anticipated!construction!actions!for!the!

planned!dredging!and!disposal!of!chemically!impacted!sediments!from!Installation!Restoration!

(IR)!Site!7,!a!portion!of!the!Long!Beach!Naval!Complex!(LBNC)!at!the!Port!of!Long!Beach!(Port),!

California.!!Remedial!action!is!required!to!comply!with!an!August!2007!Record!of!Decision!

(ROD;!USEPA!2007)!for!the!site.!!!

Specific!elements!of!this!report!include!a!description!of!the!existing!conditions!within!the!Long!

Beach!Harbor’s!West!Basin!(West!Basin),!a!review!of!the!dredge!and!disposal!plan!proposed!to!

comply!with!the!terms!of!the!final!ROD,!a!review!of!the!anticipated!construction!schedule!and!

project!sequencing,!a!summary!of!the!expected!short"term!impacts!along!with!potential!Best!

Management!Practices!(BMPs)!that!will!be!used!to!further!minimize!potential!impacts,!and!

contingency!measures!that!may!be!needed!if!construction!activities!do!not!accomplish!the!

necessary!removal!of!impacted!sediments.!

The!Port!has!separately!prepared!a!California!Environmental!Quality!Act!(CEQA)!Mitigated!

Negative!Declaration!(MND)!document!detailing!the!predicted!environmental!impacts!

anticipated!for!the!selected!remedy.!!That!same!information!has!been!summarized!in!this!

document!and!was!used!to!develop!the!recommended!construction!activity!BMPs.!!

1.1 Project Description and History

IR!Site!7!comprises!approximately!700!acres!of!submerged!land!in!the!Port,!which!was!

formerly!used!by!the!U.S.!Navy!for!training!troops!and!maneuvering,!anchoring,!berthing,!

and!maintaining!vessels.!!It!is!adjacent!to!three!former!dry!docks!used!by!the!U.S.!Navy.!!

Figure!1"1!provides!the!general!location!of!the!project!site!and!Figure!1"2!provides!a!more!

detailed!depiction!of!the!specific!areas!of!interest.!!!

In!1935,!the!U.S.!Navy!negotiated!a!30"year!lease!with!the!City!of!Long!Beach!(City)!for!

developing!the!property!into!a!naval!facility.!!The!U.S.!Navy!additionally!purchased!a!strip!

of!coastline!along!the!southern!portion!of!Terminal!Island!from!the!cities!of!Long!Beach!and!

Los!Angeles!in!1938.!!Beginning!in!1938,!the!U.S.!Navy!operated!the!LBNC!for!naval!and!

other!marine!activities,!such!as!providing!maintenance!facilities!for!the!berthing!operations!

of!tugboats,!scows,!and!similar!vessels.!!The!LBNC!provided!logistical!support!for!assigned!

IR!Site!7!(West!Basin)!Dredging!Project! 2! 060343"01!

ships!and!performed!work!in!connection!with!construction,!conversion,!overhaul,!repair,!

alteration,!dry"docking,!and!fitting!out!of!ships.!!!

During!LBNC!operation,!various!fuels,!oils,!and!other!organic!and!metal!wastes!were!

discharged!into!IR!Site!7!and!LBNC!in!general.!!From!the!early!1940s!to!the!mid"1970s,!

drainage!from!various!industrial!areas,!and!from!cleaning!and!processing!tanks,!was!

discharged!into!the!West!Basin,!which!was!within!the!boundaries!of!the!LBNC.!!It!is!

believed!that!wastes!were!discharged!through!the!storm!drain!system!and!from!the!flushing!

of!dry!docks.!!As!a!result,!surface!waters!within!the!area!received!inputs!of!heavy!metals,!

polycyclic!aromatic!hydrocarbons!(PAHs),!and!polychlorinated!biphenyls!(PCBs).!!Over!

time,!these!contaminants!accumulated!in!sediments!in!parts!of!the!West!Basin!to!levels!

predicted!to!cause!ecological!risks!to!the!resident!benthic!communities.!

After!more!than!50!years!of!service,!the!Naval!Station!Long!Beach!(NAVSTA)!was!closed!on!

September!30,!1994,!under!the!Base!Realignment!and!Closure!Act!(BRAC)!II.!!During!this!

same!year,!the!U.S.!Navy!initiated!a!comprehensive!field!sampling!effort!to!support!a!

Remedial!Investigation!(RI)!of!the!West!Basin’s!sediments!(Bechtel!1997)!following!

Comprehensive!Environmental!Response,!Compensation,!and!Liability!Act!(CERCLA)!

guidance.!!Included!in!the!RI!were!detailed!ecological!and!human!health!risk!assessments!

from!potential!exposures!to!site!sediments.!!On!September!30,!1997,!Long!Beach!Naval!

Station!(LBNS)!was!closed!under!BRAC!IV.!!During!this!period,!site!ownership!of!the!

submerged!land!(except!the!100"foot!annulus)!within!the!West!Basin!was!formally!reverted!

back!to!the!Port.!!!

The!results!of!the!RI!were!published!in!1997!and!concluded!that!no!potential!human!health!

risks!were!posed!by!site!sediments.!!The!results!did!however!conclude!that!ecological!risks!

to!benthic!organisms!residing!in!the!IR!Site!7!sediments!could!occur.!!As!a!result,!a!

subsequent!Feasibility!Study!(FS)!was!conducted!to!identify!areas!of!potential!ecological!

concern!and!possible!remedial!alternatives!for!managing!these!risks.!!The!final!FS!was!

published!in!September!2003,!which!identified!several!areas!for!sediment!remediation!and!

selected!dredging!with!on"site!disposal!as!the!preferred!alternative.!!The!final!FS!was!later!

amended!to!accept!off"site!disposal!as!an!equally!effective!alternative.!

IR!Site!7!(West!Basin)!Dredging!Project! 3! 060343"01!

Pursuant!to!the!terms!of!the!Lease!in!Furtherance!of!Conveyance!(LIFOC)!between!the!City!

and!U.S.!Navy,!the!Port!will!implement!the!required!response!and!corrective!actions!at!IR!

Site!7.!!The!Port!subsequently!entered!into!a!Consent!Agreement!with!the!California!

Environmental!Protection!Agency!(CalEPA),!Department!of!Toxic!Substances!Control!

(DTSC),!to!establish!the!process!and!timetable!for!the!Port’s!implementation!of!the!remedy!

selected!during!the!FS.!!This!work!is!required!to!be!conducted!in!a!manner!consistent!with!

the!National!Oil!and!Hazardous!Substances!Pollution!Contingency!Plan!(NCP;!40!Code!of!

Federal!Regulations![CFR]!part!300!et!seq.),!as!amended;!California!Health!and!Safety!Code!

(Sections!6.5!and!6.8),!as!amended;!and!other!applicable!federal!and!state!laws!and!

regulations.!!!

In!September!2007,!a!ROD!was!prepared!and!executed!by!the!U.S.!Navy!in!order!to!accept!

the!proposed!remedies!from!the!RI/FS.!!This!Remedial!Design!and!Remedial!Action!Work!

Plan!and!design!report!documents!the!Port’s!proposed!actions!for!complying!with!the!ROD!

as!well!as!the!Consent!Agreement!and!LIFOC.!

1.2 Cleanup Areas and Anticipated Remedial Actions

The!FS!identified,!screened,!and!evaluated!a!range!of!remedial!alternatives!to!reduce!the!

potential!for!adverse!biological!effects!estimated!for!benthic!communities!living!in!the!

chemically!impacted!sediments!of!IR!Site!7.!!

In!the!FS,!IR!Site!7!was!divided!into!seven!Areas!of!Ecological!Concern!(AOECs)!to!account!

for!variable!conditions!across!the!site!and!potentially!different!remedial!alternatives!

available!to!address!site!contaminants!within!each!area:!!!

! AOEC"A!is!in!the!northeastern!corner!of!the!West!Basin,!alongside!Pier!T.!!It!

comprises!approximately!15!acres!and!was!found!to!contain!elevated!concentrations!

of!chemical!compounds!in!surface!sediments.!!No!sediment!toxicity!or!benthic!

community!effects!were!reported.!!!!

- Note!that!AOEC"A!originally!extended!along!the!entire!northern!portion!of!the!

West!Basin!during!the!RI!phase,!but!was!dredged!by!the!Port!to!deepen!the!area!

for!shipping!berths;!the!contaminated!sediments!from!this!area!were!removed!

and!managed!in!accordance!with!state!and!federal!permits!and!requirements.!

IR!Site!7!(West!Basin)!Dredging!Project! 4! 060343"01!

! AOEC"B!is!defined!as!the!area!between!Pier!9!and!Pier!11.!!It!comprises!

approximately!80!acres!and!was!found!to!contain!elevated!chemical!concentrations!

in!surface!sediments.!!No!sediment!toxicity!or!benthic!community!effects!were!

reported.!!!

! AOEC"C!is!defined!as!the!area!between!Pier!11!and!Pier!15.!!It!comprises!

approximately!62!acres!and!was!found!to!contain!elevated!chemical!concentrations.!!

Sediment!toxicity!and!adverse!benthic!community!effects!were!reported!for!surface!

sediment.!!!

! AOEC"D!is!defined!as!the!area!offshore!of!the!tip!of!the!U.S.!Navy!Mole!and!the!

entrance!to!the!West!Basin.!!It!comprises!approximately!13!acres!and!was!found!to!

contain!one!chemical!compound!slightly!above!the!target!screening!level,!low!

toxicity,!and!no!benthic!observed!effects.!!!

! AOEC"E!is!defined!as!the!area!beneath!Pier!12!(i.e.,!Fuel!Pier).!!It!comprises!

approximately!5!acres!and!was!found!to!contain!elevated!chemical!concentrations!

and!minor!sediment!toxicity,!but!no!reports!of!adverse!benthic!community!effects.!!!

! AOEC"F!is!defined!as!the!area!beneath!Pier!15.!!It!comprises!approximately!4!acres!

and!was!found!to!contain!elevated!chemical!concentrations,!but!no!sediment!toxicity!

or!adverse!benthic!community!effects.!

! AOEC"G!is!defined!as!the!area!beneath!Pier!16.!!It!comprises!approximately!5!acres!

and!was!found!to!contain!elevated!chemical!concentration!and!minor!sediment!

toxicity,!but!no!adverse!benthic!community!effects.!!!

The!sediments!within!each!AOEC!were!individually!evaluated!against!a!range!of!remedial!

action!alternatives!to!determine!the!best!mitigation!measure!for!reducing!potentially!

adverse!biological!effects.!!Alternatives!considered!include:!!

! No!Remedial!Action.!!This!alternative!involves!leaving!the!chemically!impacted!

sediments!in!place.!!In!doing!so,!the!initiation!and/or!continuation!of!natural!

recovery!processes!would!be!ongoing.!!Any!potential!adverse!effects!due!to!factors,!

such!as!resuspension!of!chemically!impacted!sediments,!which!could!occur!with!

other!remedies,!would!be!avoided.!!!

! Limited!Action!–!Periodic!Sediment!Quality!Monitoring.!!Similar!to!the!no!remedial!

action!option,!this!alternative!would!leave!the!chemically!impacted!sediments!in!

place,!but!a!monitoring!program!would!be!established.!!The!monitoring!program!

IR!Site!7!(West!Basin)!Dredging!Project! 5! 060343"01!

would!consist!of!sediment!sampling!and!laboratory!analysis!to!determine!whether!

the!natural!recovery!processes!are!effective!in!improving!site!conditions.!!!!

! Limited!Action!–!Institutional!Controls.!!Similar!to!the!no!remedial!action!option,!this!

alternative!would!leave!the!chemically!impacted!sediments!in!place,!but!institutional!

controls!(ICs;!e.g.,!deed!restrictions)!would!be!implemented.!!Deed!restrictions!

would!include!limiting!the!future!use!of!IR!Site!7!to!Port"related!activities,!to!

maintain!access!control!and!oversight.!!Limiting!future!access!ensures!that!no!

disturbance!of!the!subsurface!sediments!would!occur!without!prior!authorization!

and!evaluation!and!also!restricts!disturbance!of!any!chemically!impacted!sediment!

that!is!left!in!place!or!used!as!fill!at!other!locations.!!!!!!!

! In!Situ!Capping!of!AOEC!Areas!with!“Clean”!Imported!Sediments.!!This!alterative!would!

leave!chemically!impacted!sediments!in!place!and!would!cap!them!with!an!isolating!

medium,!such!as!imported!“clean”!dredged!material.!!A!monitoring!program!would!

also!be!implemented!to!ensure!the!cap!is!placed!as!intended,!is!effective!in!isolating!

the!sediments!from!the!environment,!and!is!maintaining!its!design!thickness.!!!!

! Removal!and!On"site!(Within!IR!Site!7)!Containment!of!AOEC!Sediments!–!Discharge!of!

Dredged!Material!along!Inboard!Face!of!U.S.!Navy!Mole.!!This!alternative!would!remove!

the!chemically!impacted!sediments!and!place!them!within!a!diked!containment!area!

constructed!on!top!of!chemically!impacted!sediments!within!IR!Site!7.!!The!

containment!area!would!be!capped!with!a!2"foot"thick!layer!of!“clean”!sediment!and!

a!1"foot!cover!of!asphalt!pavement.!!

! Removal!and!Off"site!(Outside!IR!Site!7)!Containment!of!AOEC!Sediments!–!Discharge!of!

Dredged!Material!along!Outboard!Face!of!U.S.!Navy!Mole.!!This!alternative!would!

remove!the!chemically!impacted!sediments!and!place!them!within!a!diked!

containment!area!constructed!on!top!of!chemically!impacted!sediments!outside!the!

IR!Site!7!boundary.!!The!containment!area!would!be!capped!with!a!2"foot"thick!layer!

of!“clean”!sediment!and!a!1"foot!cover!of!asphalt!pavement.!!!

! Removal!and!Discharge!of!AOEC!Sediments!at!Off"site!(Outside!IR!Site!7)!Projects.!!This!

alternative!would!remove!chemically!impacted!sediments!and!discharge!them!

outside!of!the!IR!Site!7!boundary,!such!as!at!a!Port!development!project!like!the!Pier!

G!Slip!Fill.!!!!!!!

IR!Site!7!(West!Basin)!Dredging!Project! 6! 060343"01!

A!comparative!analysis!of!the!advantages!and!disadvantages!of!each!remedial!action!

alternative,!by!AOEC,!resulted!in!a!determination!of!the!preferred!remedial!action!

alternative!(Proposed!Plan),!as!detailed!in!Bechtel!(1997).!!Each!of!these!remedial!

alternatives!was!further!evaluated!against!the!Threshold!Criteria!and!the!Primary!Balancing!

Criteria!as!defined!in!the!NCP.!!Threshold!Criteria!apply!to!the!overall!protection!of!human!

health!and!the!environment!and!compliance!with!federal!and!state!applicable!or!relevant!

and!appropriate!requirements.!!Primary!Balancing!Criteria!weigh!the!positives!and!

negatives!of!each!alternative!in!terms!of!long"term!effectiveness!and!permanence,!reduction!

of!toxicity,!mobility!or!volume,!short"term!effectiveness,!implementability,!and!cost.!!!!

The!Proposed!Plan,!selected!through!the!FS!process,!provides!the!greatest!level!of!protection!

to!IR!Site!7!benthic!communities,!achieves!the!remedial!action!objectives,!provides!the!

greatest!level!of!long"term!effectiveness!and!permanence,!and!is!easily!implementable.!!The!

remedies!of!the!Proposed!Plan!include:!!

! AOEC"A!and!AOEC"C:!!Removal!of!the!AOEC!sediments!and!disposal!at!off"site!

(outside!IR!Site!7)!projects,!thereby!creating!a!clean!substrate!supporting!the!

presence!of!an!ecologically!productive!and!diverse!benthic!community!

! AOEC"B:!!No!remedial!action!necessary!to!protect!the!environment!as!chemical!

concentrations!have!not!resulted!in!sediment!toxicity!or!adverse!effects!on!the!

benthic!community!!

! AOEC"E,!AOEC"F,!and!AOEC"G!(Pier!AOECs):!!Limited!action!necessary!for!ICs!to!

be!implemented!for!the!purpose!of!preventing!unauthorized!or!uncontrolled!

disturbance!and/or!exposure!of!beneath"pier!chemically!impacted!sediments!!!

Since!AOEC"B!was!accepted!as!a!no!remedial!action!necessary!area!and!does!not!require!a!

formal!remedy,!AOEC"B!is!not!discussed!further!in!this!report.!!The!remainder!of!this!report!

will!focus!on!remedial!action!efforts!for!AOEC"A,!AOEC"C,!AOEC"E,!AOEC"F,!and!

AOEC"G.!!For!purposes!of!evaluation,!AOEC"C!will!be!subdivided!into!two!areas:!AOEC"C!

East!(area!to!the!east!of!Pier!12)!and!AOEC"C!West!(area!to!the!west!of!Pier!12).!!This!

division!is!based!on!sediment!contamination!potential.!!Figure!1"2!depicts!the!layout!of!the!

project!site!and!the!location!of!each!AOEC.!

IR!Site!7!(West!Basin)!Dredging!Project! 7! 060343"01!

1.3 General Description of Remedial Action

The!Remedial!Action!Objective!(RAO)!for!the!chemically!impacted!sediments!of!IR!Site!7!is!

to!protect!the!ecologically!productive!and!diverse!benthic!community!within!each!of!the!

AOEC!areas!and!to!be!consistent!with!the!existing!land!use!(Port"related!and!industrial).!

1.3.1 AOEC-A and AOEC-C

The!selected!remedial!alternative!for!AOEC"A!and!AOEC"C!involves!eliminating!the!

pathway!for!potential!risk!from!chemicals!of!ecological!concern!(COECs)!to!the!resident!

benthic!community!by!dredging!impacted!sediments!and!disposing!of!them!at!an!off" site!location!(i.e.,!Pier!G!Slip!Fill!site)!designed!to!house!such!material.!!Sediments!are!

considered!to!be!“impacted”!if!they!contain!chemical!concentrations!for!one!or!more!

COEC!in!excess!of!the!Sediment!Management!Objectives!(SMOs)!developed!for!the!

project!and!defined!in!the!ROD!(Table!1"1).!!

In!order!to!fulfill!the!requirements!of!the!LIFOC!and!SMOs!as!outlined!in!the!U.S.!

Navy’s!ROD!for!the!property,!the!Port!intends!to!remove!up!to!approximately!800,000!

cubic!yards!(cy)!of!chemically!impacted!sediments!from!IR!Site!7.!!The!dredged!material!

will!be!placed!in!the!previously!authorized!Pier!G!Slip!Fill!site!located!near!the!West!

Basin!for!final!confined!disposal.!!The!practice!of!disposing!impacted!sediments!inside!

engineered!port!fills!is!extremely!common!globally,!nationally,!and!regionally.!!The!

construction!and!placement!methods!have!been!developed!and!refined!over!the!past!30!

years!and!significant!long"term!monitoring!data!exists!to!show!that!port!fills!are!very!

effective!in!isolating!contaminated!sediments.!!Disposal!activities!inside!port!fills!are!

managed!under!the!Clean!Water!Act!and,!as!with!the!construction!process,!water!quality!

monitoring!techniques!are!equally!advanced.!!Documentation!to!demonstrate!the!

environmental!protectiveness!of!this!planned!management!technique!is!provided!in!

Section!5.4!of!this!report.!

Specifically,!in!order!to!fulfill!the!proposed!project’s!purpose,!the!Port!must!undertake!

the!following!actions!related!to!the!chemically!impacted!sediments!in!the!West!Basin:!

! Remove!four!sunken!barges!from!AOEC"C!East!and!West!

! Remove!the!abandoned!sonar!calibration!pier!from!the!U.S.!Navy!Mole!on!the!

southern!portion!of!IR!Site!7!in!AOEC"C!West!

IR!Site!7!(West!Basin)!Dredging!Project! 8! 060343"01!

! Dredge!a!sufficient!volume!of!material!from!AOEC"A!and!AOEC"C!to!achieve!

the!target!cleanup!goals!(to!be!verified!by!confirmation!sampling)!

! Transport!the!dredged!material!to!the!separately!permitted!Pier!G!Slip!Fill!site!

for!final!confined!disposal!

Dredging!remedies!would!achieve!the!RAO!upon!confirmation!that!the!targeted!

sediments!have!been!removed!as!planned!and!would!preclude!the!need!for!further!

remedial!action.!!

1.3.2 AOEC-E

The!selected!remedy!for!limited!action!AOEC"E!involves!implementing!ICs!to!prevent!

unauthorized!or!uncontrolled!disturbance!and/or!exposure!to!the!chemically!impacted!

sediments!while!still!maintaining!use!of!the!area.!!The!Port!will!be!responsible!for!

implementing!the!following:!

! ICs!in!the!form!of!administrative!mechanisms!

! CERCLA!statutory!5"year!reviews!of!the!ICs!remedy!in!perpetuity!or!until!ICs!

have!been!released!or!terminated!when!ecological!risk!no!longer!exists!

1.3.3 AOEC-F and AOEC-G

The!selected!remedy!for!AOEC"F!and!AOEC"G!calls!for!implementing!ICs!to!prevent!

unauthorized!or!uncontrolled!disturbance!and/or!exposure!of!these!sediments!while!still!

maintaining!use!of!the!areas.!!The!Port!will!be!responsible!for!implementing!the!

following:!

! ICs!in!the!form!of!legal!mechanisms!

! Land"use!control!covenants!to!restrict!use!of!property!to!Port"related!and!

industrial!uses!to!be!executed!between!the!Port,!CalEPA!DTSC,!and!Los!Angeles!

Regional!Water!Quality!Control!Board!(LARWQCB),!and!enforced!as!applicable!

on!future!real!property!owners!

! CERCLA!statutory!5"year!reviews!of!the!ICs!remedy!in!perpetuity!or!until!ICs!

have!been!released!or!terminated!when!ecological!risk!no!longer!exists!

IR!Site!7!(West!Basin)!Dredging!Project! 9! 060343"01!

1.4 Applicable or Relevant and Appropriate Requirements

Applicable!or!Relevant!and!Appropriate!Requirements!(ARARs)!are!cleanup!standards,!

standards!of!control,!and!other!substantive!environmental!protection!requirements,!criteria,!

or!limitations!promulgated!under!federal!or!state!law.!!

For!AOEC"A!and!AOEC"C,!the!FS!concluded!that!(at!a!minimum)!the!following!ARARs!

should!be!implemented:!

1. Chemical"Specific.!!Chemical"specific!ARARs!are!health!or!risk"based!numerical!

values!or!methodologies!that,!when!applied!to!site"specific!conditions,!establish!the!

acceptable!ecological!risk!screening!values!for!cleanup.!!During!the!FS,!chemical!

concentrations!for!which!there!would!be!no!cause!of!concern!for!ecological!risk!were!

determined!using!a!sediment!triad!approach.!!The!resulting!specific!concentration!

thresholds!for!COECs!are!listed!in!Table!1"1.!!These!values!were!used!to!define!the!

site!SMOs!and!therefore!were!the!basis!for!determining!the!required!areas!and!

depths!of!sediment!removal!at!AOEC"A!and!AOEC"C.!

2.! Location"Specific.!!In!addition!to!requirements!related!to!the!protection!of!identified!

bird!and!mammal!species,!associated!prey!and!habitat,!and!water!quality,!the!

location"specific!ARARs!applicable!to!this!alternative!include!technical!requirements!

of!the!Rivers!and!Harbors!Act!for!construction!of!dikes!and!areas!near!navigation!

lanes.!!The!site"specific!ecological!risk!assessment!results!indicate!that!the!protected!

species!identified!for!the!IR!Site!7!AOECs!are!not!considered!to!be!among!potential!

receptors.!!The!potential!risk!posed!by!the!impacted!AOEC!sediments!for!marine!

mammals!is!estimated!as!low!and!could!not!be!directly!related!to!site!conditions.!!

Remedial!action!will!further!minimize!the!potential!risk!posed!by!sediment!COECs!

and!will!be!conducted!in!a!manner!protective!of!wildlife!species.!!After!removal!of!

the!chemically!impacted!sediments,!the!remaining!AOEC"A!and!AOEC"C!sediments!

would!not!be!expected!to!pose!a!potential!risk!to!the!marine!environment.!!!

3.! Action"Specific.!!Sediment!removal!with!the!use!of!dredging!equipment!is!a!common!

occurrence!in!harbor!areas,!and!a!remedial!action!is!not!likely!to!interrupt!regular!

Port!traffic!or!habitats!for!migratory!birds.!!Relocation!of!AOEC"A!and!AOEC"C!

sediments!is!not!expected!to!introduce!materials!that!would!adversely!impact!water!

quality!and!be!inconsistent!with!beneficial!uses!of!Los!Angeles!and!Long!Beach!

Harbors.!!The!impact!of!dredging!on!water!quality!is!expected!to!be!limited!to!

IR!Site!7!(West!Basin)!Dredging!Project! 10! 060343"01!

resuspension!of!AOEC"A!and!AOEC"C!sediments!in!the!water!column!in!the!

immediate!work!area.!!This!will!be!monitored!and!mitigated,!if!necessary,!using!the!

following!approach:!

! The!water!column!will!be!monitored!in!accordance!with!the!substantive!

provisions!of!Section!6!of!the!LARWQCB!Basin!Plan!as!related!to!discharge!of!

dredged!sediments.!!!

! The!monitoring!results!will!be!compared!to!the!LARWQCB!Basin!Plan’s!

Water!Quality!Objectives!and!to!federal!water!quality!standards.!!!

! Silt!curtains!surrounding!the!dredge!areas!will!minimize!the!extent!of!the!

water!affected!by!increased!turbidity!and!sediment!resuspension!(Bechtel!

2003).!!

For!a!complete!description!of!ARARs!that!pertain!to!this!project,!including!applicable!

federal!and!state!codes!and!acts,!please!refer!to!Appendix!A!of!the!Final!Feasibility!Study!

Report!(Bechtel!2003)!or!Section!13!of!the!ROD!(USEPA!2007).!!

Existing!Conditions!

IR!Site!7!(West!Basin)!Dredging!Project! 11! 060343"01!

2 EXISTING CONDITIONS

2.1 Physical and Chemical Conditions

Physical!properties!of!surface!and!subsurface!sediments!throughout!IR!Site!7!were!

evaluated!through!laboratory!grain!size!analyses,!total!organic!carbon!(TOC),!and!

observations!made!during!sampling!activities.!!IR!Site!7!sediments!were!observed!to!be!

primarily!fine"grained!(i.e.,!sediment!particles!smaller!than!62.5!micrometers),!averaging!65!

percent!fines!overall.!!Surface!sediment!samples!collected!near!the!IR!Sites!7!entrance!

contained!a!high!percentage!of!coarser,!sand"sized!particles.!!Sediments!located!beneath!

piers,!along!the!northern!seawall,!and!along!the!U.S.!Navy!Mole!contained!a!greater!

percentage!of!fine"grained!particles,!more!so!than!the!central!areas!of!IR!Site!7.!!TOC!was!

found!in!a!distribution!similar!to!that!of!the!sediment!fines,!with!greater!concentrations!

along!the!northern!seawall,!the!U.S.!Navy!Mole,!and!beneath!the!piers!(Bechtel!2003).!!!!

Chemical!properties!of!surface!and!subsurface!sediments!were!evaluated!through!

laboratory!analyses.!!Previous!studies!conducted!within!IR!Site!7,!by!MEC!Analytical!Inc.,!in!

1999!and!Bechtel!International,!Inc.,!in!2003,!characterized!surface!sediments!along!the!

docks!and!piers!as!being!contaminated!with!PAHs,!the!pesticide!dichloro!diphenyl!

trichloroethane!(DDT),!PCBs,!and!heavy!metals.!!However,!central!areas!of!the!West!Basin!

were!less!contaminated!than!the!nearshore!areas.!!The!principal!contaminants!of!concern!in!

the!central!areas!are!PAHs.!!!

Sampling!conducted!during!the!FS!in!1998!(Bechtel!2003)!demonstrated!that!specifically!in!

AOEC"A,!mercury!was!significantly!elevated!above!SMOs!to!a!depth!of!approximately!5!

feet;!however,!no!significant!biological!effects!were!detected!in!toxicity!tests.!!In!AOEC"C!

East!and!West,!mercury,!lead,!PAHs,!and!total!PCBs!were!elevated!in!surface!sediments!to!

approximately!3!feet.!!Additional,!toxicity!to!echinoderms,!as!well!as!benthic!community!

effects,!were!observed!in!sediments!for!AOEC"C!East!and!West.!!!!!!

Additional!sediment!sampling!was!conducted!in!AOEC"A,!AOEC"C!East,!and!AOEC"C!

West!by!Weston!Solutions,!Inc.!(Weston),!in!June!2007!in!order!to!confirm!the!results!of!the!

FS!and!further!delineate!the!vertical!and!horizontal!sediment!contamination!within!the!

dredging!parameters!of!IR!Site!7!(Tables!2"1!through!2"13).!!Sampling!locations!are!shown!in!

Figure!2"1.!!In!AOEC"A,!results!of!1"foot!interval!sampling!per!core!location!indicated!

IR!Site!7!(West!Basin)!Dredging!Project! 12! 060343"01!

copper,!lead,!mercury,!and!zinc!were!detected!at!concentrations!greater!than!the!SMOs!only!

in!the!top!3!feet!of!sediment!with!the!exception!of!two!sampling!locations!where!mercury!

and!zinc!exceeded!SMOs!as!deep!as!4!feet.!!As!an!area"wide!composite,!arsenic,!copper,!

mercury,!nickel,!and!zinc!were!detected!at!concentrations!below!SMOs!in!AOEC"A.!!In!

AOEC!C"East,!no!metals!were!detected!at!concentrations!in!exceedance!of!their!respective!

SMOs,!for!both!1"foot!interval!sampling!and!area!wide!composite!sampling.!!In!AOEC"C!

West,!results!of!1"foot!interval!sampling!per!core!location!indicated!mercury!and!zinc!were!

detected!at!concentrations!greater!than!the!SMOs!only!in!the!top!4!feet!of!sediment.!!In!an!

area"wide!composite!for!AOEC"C!West,!copper,!nickel,!and!zinc!were!detected!at!

concentrations!below!SMOs.!!!

During!the!environmental!review!process!for!the!IR!Site!7!project,!DTSC!raised!a!concern!

regarding!potentially!elevated!Soluble!Threshold!Limit!Concentrations!(STLC)!estimated!for!

the!West!Basin!dredged!material!based!on!total!concentrations.!!To!address!these!concerns,!

and!to!prove!that!none!of!the!material!proposed!for!dredging!would!be!considered!

“hazardous!material”!under!California!Code!of!Regulation!(CCR)!Title!22!regulations,!the!

Port!selected!six!samples!from!its!last!round!of!dredged!material!characterization!(Weston!

2007)!that!contained!the!highest!total!metals!(i.e.,!copper,!lead,!and!mercury)!concentrations!

and!sent!them!to!an!analytical!laboratory!for!rush!turnaround!time!STLC!testing.!!The!total!

metals!results!for!these!six!samples!were!comparable!with!the!highest!values!observed!

during!the!entire!FS!and!remedial!design!process.1!!The!results!of!those!tests,!presented!in!

Table!2"14,!confirmed!the!Port’s!prediction!that!little,!if!any,!additional!leaching!would!

occur!from!the!marine!sediments.!!

Measured!STLCs!were!all!well!below!the!CCR!Title!22!STLC!thresholds,!and!more!than!70!

percent!of!the!analyses!contained!non"detectable!concentrations!in!the!leachate.!!As!a!result,!

this!data!confirms!that!the!material!is!not!a!“hazardous!waste”!according!to!the!CCR!Title!22!

regulations!and!would!not!pose!a!risk!to!groundwater!resources,!even!if!an!underlying!

groundwater!source!did!exist!at!Pier!G!Slip!Fill!site.!!These!results!are!not!surprising!

because!the!affected!sediments!have!been!submerged!in!the!marine!environment!for!about!

50!years,!and!thus,!any!readily!leachable!metals!or!organic!compounds!would!have!already!

1.!A!total!of!approximately!500!samples!have!been!tested!to!date!from!over!110!distinct!sample!stations!located!within!the!proposed!dredge!prism.!!The!samples!

selected!for!STLC!testing!represent!the!upper!end!of!the!range!of!concentrations!observed!during!any!of!the!previous!site!investigations.!

IR!Site!7!(West!Basin)!Dredging!Project! 13! 060343"01!

partitioned!into!the!water!column!and!been!carried!away!from!the!site!by!the!prevailing!

currents.!!This!theory!is!supported!by!the!basic!concepts!of!equilibrium!partitioning!in!

sediments,!which!states!that!in!order!for!contaminants!to!cross!the!interface!between!

dredged!material!solids!and!water,!there!must!be!a!difference!in!chemical!potentials.!!When!

chemical!potentials!are!equal,!the!net!transfer!of!contaminants!across!the!solid"water!

interface!is!zero,!and!the!mass!of!contaminant!in!each!phase!is!constant!but!not!necessarily!

equal.!!This!stage!is!considered!to!be!the!equilibrium!condition,!and!the!ratio!of!contaminant!

mass!in!the!solid!phase!to!contaminant!mass!in!the!aqueous!phase!does!not!change.!!Over!

time,!as!the!gradient!between!the!sediment!and!water!phases!are!minimized,!the!rate!of!

partitioning!is!reduced.!

2.2 Surrounding Land Use

General!land!use!at!and!in!the!vicinity!of!the!former!LBNC,!IR!Site!7,!and!the!future!Pier!G!

Slip!Fill!site!is!primarily!Port"related!and!industrial.!!Facilities!immediately!surrounding!IR!

Site!7!include!tank!farms;!automobile",!cement",!and!cargo"handling!terminals;!and!storage!

terminals.!!The!areas!east!and!west!of!IR!Site!7!are!used!for!commercial!shipping,!liquid!bulk!

handling,!heavy!industrial!activities!and!commercial!fishing!activities.!!The!area!north!of!the!

former!LBNC!is!used!for!oil!production!activities.!!Terminal!Island,!where!the!former!LBNC!

once!operated,!comprises!the!western!portion!of!the!Port!and!the!eastern!portion!of!the!Port!

of!Los!Angeles.!!These!ports!participate!in!heavy!shipping!traffic,!container!storage,!cargo!

handling,!dredging!activities,!and!loading/offloading!operations.!!The!future!use!of!IR!Site!7!

is!identified!as!Port"related!and!industrial!(Bechtel!1997).!

The!area!slated!for!disposal!of!IR!Site!7!contaminated!sediments,!the!Pier!G!Slip!Fill!site,!is!a!

2,500"foot"long!by!500"foot"wide!slip!that!extends!north!from!the!Southeast!Basin!and!

essentially!bisects!Pier!G.!!This!area!is!used!for!container!cargo!offloading!and!storage.!!

Dredged!material!will!be!placed!in!a!matter!that!will!not!change!the!existing!land!use.!!The!

dredged!material!will!be!placed!behind!a!200"foot"thick!berm,!topped!with!40!feet!of!clean,!

sandy!material,!and!paved!with!asphalt.!!

2.3 Hydraulic Conditions

Southern!California!coastal!tides!are!semidiurnal,!with!two!low!and!two!high!tides!of!

unequal!height!every!25!hours.!!Rising!tides,!which!vary!with!the!phase!of!the!moon,!enter!

IR!Site!7!(West!Basin)!Dredging!Project! 14! 060343"01!

Long!Beach!Harbor!and!flow!up!the!various!channels!and!basins!while!falling!tides!flow!in!

reverse.!!Tidal!currents!generally!create!water!circulation!patterns,!which!occur!in!a!

clockwise!manner!within!IR!Site!7.!!Mean!tide!in!Long!Beach!Harbor!has!a!maximum!range!

of!5.5!feet.!!The!maximum!velocity!at!the!entrance!to!Los!Angeles!and!Long!Beach!Harbors!

has!been!estimated!at!0.54!feet!per!second!for!ebb!tide!and!0.46!feet!per!second!for!flood!

tide.!!Velocity!magnitudes!throughout!Los!Angeles!and!Long!Beach!Harbors!generally!are!

small,!usually!less!than!1!foot!per!second.!!The!temperature!within!the!IR!Site!7!water!

column!varies!by!season;!it!is!cooler!in!the!winter!and!warmer!in!the!spring!and!summer.!!

The!water!depth!of!IR!Site!7!is!generally!uniform!with!an!average!water!depth!of!

approximately!40!feet!mean!lower!low!water!(MLLW).!!As!a!result!of!dredging!by!the!Port,!

there!is!a!deeper!(55!feet!MLLW)!area!along!the!northern!portions!of!IR!Site!7!and!a!

shallower!(40!feet!MLLW)!area!in!the!western!portion!of!the!site!(Bechtel!1997).!!

2.4 Geotechnical and Structural Conditions

Appendix!A1!of!the!Final!Feasibility!Study!Report!(Bechtel!2003)!presents!a!compilation!of!

physical!and!chemical!data!for!site!sediments,!as!well!as!soils!underlying!the!surrounding!

land!mass.!!Based!on!this!information,!sediments!in!the!IR!Site!7!dredging!area!consist!

primarily!of!interbedded!silty!sands!and!sandy!silts.!!The!sediment!grain!sizes!ranged!

considerably,!from!90!percent!fines!to!coarse"grained!sediment!(78!percent!sand).!!The!

coarsest!sediment!size!was!found!near!the!entrance!to!the!West!Basin.!!

The!current!mudline!is!approximately!10!to!20!feet!deeper!than!estimated!historic!mudline!

surfaces!in!1909!and!1937!(Bechtel!2003).!!There!are!no!known!or!documented!submerged!

geological!features!at!the!current!mudline!grade,!such!as!rock!outcrops.!!Some!instances!of!

submerged!debris!(including!sunken!scows)!are!known!to!exist!at!the!site!and!will!be!

removed!in!their!entirety!to!complete!dredging.!

The!shoreline!of!IR!Site!7!is!lined!with!riprap"armored!slopes!and!pile"supported!piers!

(Bechtel!1997),!and!the!areas!planned!for!dredging!are!adjoined!by!existing!structures,!

including!the!U.S.!Navy!Mole,!Pier!E,!and!the!pile"supported!Piers!10,!11,!and!12.!!!

IR!Site!7!(West!Basin)!Dredging!Project! 15! 060343"01!

2.5 Potential for Site Recontamination

After!dredging!is!accomplished,!the!potential!for!sediment!recontamination!is!typically!

dictated!by!the!degree!to!which!source!control!measures!are!implemented!at!the!site,!as!well!

as!the!proximity!of!external!sediment!sources!(such!as!river!mouths!or!outfalls!carrying!

runoff!from!adjacent!parcels).!!Since!the!U.S.!Navy!has!vacated!the!site,!previous!operational!

practices!have!been!discontinued!and,!therefore,!will!not!be!a!cause!of!future!

recontamination.!!The!Port’s!marine!terminal!operations!are!not!expected!to!contribute!to!

sediment!recontamination.!!Meanwhile,!the!nearest!off"site!source!of!contaminated!sediment!

is!the!Dominguez!Channel,!which!drains!a!portion!of!the!greater!south!Los!Angeles!area.!!

Portions!of!the!Dominguez!Channel!flow!through!the!Back!Channel!and!Cerritos!Channel!

before!entering!the!Long!Beach!Middle!Harbor!(just!east!of!the!proposed!dredging!areas),!

which!could!represent!a!potential!source!of!future!waterborne!containments.!!The!U.S.!

Environmental!Protection!Agency!(USEPA)!and!LARWQCB!are!actively!working!to!

remediate!and!restore!the!Dominguez!Channel;!therefore,!the!potential!for!it!to!become!a!

future!source!of!containments!to!IR!Site!7!is!likely!very!small.!!No!other!known!inputs!to!the!

area!are!documented.!!Any!sources!of!chemical!contamination!caused!by!on"site!sediments!

will!be!removed!in!the!process!of!conducting!this!dredging!project.!

Dredge!and!Disposal!Plan!

IR!Site!7!(West!Basin)!Dredging!Project! 16! 060343"01!

3 DREDGE AND DISPOSAL PLAN

The!Port!intends!to!dredge!up!to!approximately!800,000!cy!of!chemically!impacted!sediments!

from!AOEC"A,!AOEC"C!East,!and!AOEC"C!West,!as!shown!on!Figure!1"2.!!Further!detail!on!the!

dredging!plan!is!provided!in!the!Construction!Plans!for!the!project,!which!were!developed!by!

KPFF!Consulting!Engineers!(KPFF)!and!are!included!as!Appendix!A!of!this!report.!!A!typical!

plan!view!for!AOEC"C!West!and!a!cross!section!of!the!dredging!plan!for!AOEC"A,!prepared!by!

KPFF,!are!shown!on!Figure!3"1!and!Figure!3"2.!!Because!the!engineering!design!documents!were!

not!finalized!as!contract!documents!at!the!time!of!this!document’s!production,!and!because!a!

contractor!has!not!yet!be!retained!to!complete!the!work,!all!design!information!and!specific!

equipment!references!presented!in!this!document!should!be!considered!“reasonable!and!

conservative!estimates”!for!purposes!of!evaluatin…