Contaminated Sediment Remediation Guidance for Hazardous

5,73

MB

Waste Sites

218

stron

4145

ID

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

2005

rok

TABLE OF CONTENTS

Appendices. ix

Highlights x

1.0 INTRODUCTION .1-1

1.1 PURPOSE .1-1

1.2 CONTAMINATED SEDIMENT .1-2

1.3 RISK MANAGEMENT PRINCIPLES AND REMEDIAL APPROACHES 1-3

1.3.1 Remedial Approaches 1-5

1.3.2 Urban Revitalization and Reuse.1-6

1.4 DECISION-MAKING PROCESS.1-7

1.4.1 Decision Process Framework.1-7

1.4.2 Technical Support 1-10

1.5 STATE, TRIBAL, AND TRUSTEE INVOLVEMENT .1-11

1.6 COMMUNITY AND OTHER STAKEHOLDER INVOLVEMENT . 1-12

2.0 REMEDIAL INVESTIGATION CONSIDERATIONS.2-1

2.1 SITE CHARACTERIZATION .2-1

2.1.1 Data Quality Objectives.2-2

2.1.2 Types of Data.2-3

2.1.3 Background Data 2-6

2.2 CONCEPTUAL SITE MODELS .2-7

2.3 RISK ASSESSMENT .2-12

2.3.1 Screening Risk Assessment .2-13

2.3.2 Baseline Risk Assessment 2-14

2.3.3 Risks from Remedial Options .2-14

2.4 CLEANUP GOALS.2-14

2.4.1 Remedial Action Objectives and Remediation Goals . 2-15

2.4.2 Cleanup Levels.2-16

2.5 WATERSHED CONSIDERATIONS .2-17

2.5.1 Role of the Contaminated Water Body 2-18

2.5.2 Water Body and Land Uses .2-18

2.6 SOURCE CONTROL .2-20

2.7 PHASED APPROACHES AND EARLY ACTIONS.2-21

2.8 SEDIMENT STABILITY AND CONTAMINANT FATE AND TRANSPORT 2-22

2.8.1 Data Collection 2-25

2.8.2 Routine and Extreme Events 2-27

2.8.3 Bioturbation .2-30

2.8.4 Predicting the Consequences of Sediment and Contaminant Movement 2-31

2.9 MODELING 2-32

2.9.1 Sediment/Contaminant Transport and Fate Model Characteristics . 2-33

2.9.2 Determining Whether A Mathematical Model is Appropriate . 2-36

2.9.3 Determining the Appropriate Level of Model .2-36

2.9.4 Peer Review .2-40

3.0 FEASIBILITY STUDY CONSIDERATIONS3-1

3.1 DEVELOPING REMEDIAL ALTERNATIVES FOR SEDIMENT 3-1

3.1.1 Alternatives which Combine Approaches .3-2

3.1.2 The No-Action Alternative 3-3

3.1.3 In-Situ Treatment Alternatives3-3

3.2 NCP REMEDY SELECTION CRITERIA 3-5

3.3 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS FOR SEDIMENT

ALTERNATIVES 3-7

3.4 LONG-TERM EFFECTIVENESS AND PERMANENCE OF SEDIMENT ALTERNATIVES 3-12

3.5 COST 3-15

3.5.1 Capital Costs 3-15

3.5.2 Operation and Maintenance Costs 3-18

3.5.3 Net Present Value 3-19

3.5.4 State Cost Share 3-19

3.6 INSTITUTIONAL CONTROLS .3-20

4.0 MONITORED NATURAL RECOVERY .4-1

4.1 INTRODUCTION .4-1

4.2 POTENTIAL ADVANTAGES AND LIMITATIONS .4-3

4.3 LINES OF EVIDENCE .4-4

4.4 NATURAL RECOVERY PROCESSES 4-6

4.4.1 Physical Processes .4-7

4.4.2 Biological and Chemical Processes 4-8

4.5 ENHANCED NATURAL RECOVERY .4-10

4.6 ADDITIONAL CONSIDERATIONS .4-11

5.0 IN-SITU CAPPING 5-1

5.1 INTRODUCTION .5-1

5.2 POTENTIAL ADVANTAGES AND LIMITATIONS .5-3

5.3 EVALUATING SITE CONDITIONS5-3

5.3.1 Physical Environment 5-4

5.3.2 Sediment Characteristics 5-4

5.3.3 Waterway Uses and Infrastructure.5-5

5.3.4 Habitat Alterations.5-6

5.4 FUNCTIONAL COMPONENTS OF A CAP 5-7

5.4.1 Physical Isolation Component .5-7

5.4.2 Stabilization/Erosion Protection Component.5-8

5.4.3 Chemical Isolation Component .5-9

5.5 OTHER CAPPING CONSIDERATIONS5-10

5.5.1 Identification of Capping Materials.5-11

5.5.2 Geotechnical Considerations 5-13

5.5.3 Placement Methods .5-13

5.5.4 Performance Monitoring .5-14

6.0 DREDGING AND EXCAVATION 6-1

6.1 INTRODUCTION .6-1

6.2 POTENTIAL ADVANTAGES AND LIMITATIONS .6-3

6.3 SITE CONDITIONS .6-5

6.3.1 Physical Environment 6-5

6.3.2 Waterway Uses and Infrastructures 6-6

6.3.3 Habitat Alteration6-6

6.4 EXCAVATION TECHNOLOGIES .6-7

6.5 DREDGING TECHNOLOGIES .6-10

6.5.1 Mechanical Dredging6-10

6.5.2 Hydraulic Dredging .6-11

6.5.3 Dredge Equipment Selection 6-12

6.5.4 Dredge Positioning6-20

6.5.5 Predicting and Minimizing Resuspension, Contaminant Release and Transport During Dredging

.6-21

6.5.6 Containment Barriers6-23

6.5.7 Predicting and Minimizing Dredging Residuals .6-25

6.6 TRANSPORT, STAGING, AND DEWATERING.6-27

6.7 SEDIMENT TREATMENT 6-29

6.7.1 Pre-Treatment .6-29

6.7.2 Treatment .6-30

6.7.3 Beneficial Use .6-33

6.8 SEDIMENT DISPOSAL .6-34

6.8.1 Sanitary/Hazardous Waste Landfills 6-34

6.8.2 Confined Disposal Facilities 6-35

6.8.3 Contained Aquatic Disposal 6-36

6.8.4 Losses from Disposal Facilities 6-36

7.0 REMEDY SELECTION CONSIDERATIONS .7-1

7.1 NCP REMEDY SELECTION FRAMEWORK 7-2

7.2 CONSIDERING REMEDIES 7-4

7.3 COMPARING NET RISK REDUCTION7-14

7.4 CONSIDERING INSTITUTIONAL CONTROLS .7-16

7.5 CONSIDERING NO-ACTION 7-17

7.6 CONCLUSIONS .7-18

8.0 REMEDIAL ACTION AND LONG-TERM MONITORING .8-1

8.1 INTRODUCTION .8-1

8.2 SIX RECOMMENDED STEPS FOR SITE MONITORING 8-3

8.3 POTENTIAL MONITORING TECHNIQUES.8-8

8.3.1 Physical Measurements .8-9

8.3.2 Chemical Measurements .8-10

8.3.3 Biological Measurements.8-10

8.4 REMEDY-SPECIFIC MONITORING APPROACHES.8-11

8.4.1 Monitoring Natural Recovery .8-11

8.4.2 Monitoring In-Situ Capping.8-13

APPENDICES

A PRINCIPLES FOR MANAGING CONTAMINATED SEDIMENT RISKS AT HAZARDOUS WASTE

SITES . A-1