In-Situ Capping of Contaminated Sediments - a PDH Online Course for Engineers, Architects and Surveyors

In-Situ Capping of Contaminated Sediments

Course Outline

This online course provides an introduction to in-situ capping as a remedial approach for contaminated sediment sites. Specific topics include advantages and limitations of in-situ capping, evaluation of site conditions that may impact feasibility or effectiveness of a capping strategy, functional components of caps, and other considerations that must be accounted for in the cap design. The course also introduces concepts in cap design methods including identification of capping materials; evaluation of physical, chemical, and erosion protection components; and geotechnical and operational considerations.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will

Understand the challenges associated with in-situ capping of contaminated sediments;
Understand the potential advantages and limitations of in-situ capping as a remedial strategy;
Develop an understanding of how various site conditions can effect the appropriateness, effectiveness, or viability of a contemplated capping strategy;
Understand the functional components of a cap;
Develop an understanding of common types of cap materials, and identification of cap materials in cap design;
Understand how capping strategies can be used to physically isolate contaminated sediment from the environment;
Understand how various capping strategies can be used to chemically isolate contaminated sediment from the environment;
Understand how various capping strategies can be used to stabilize contaminated sediments and to protect against erosional processes;
Develop a basic understanding of the operational considerations associated with in-situ capping strategies;
Develop an understanding of placement methods for in-situ caps;
Understand the processes that should be considered when developing a performance monitoring program for a capping strategy;
Understand how interactions of cap components can be accounted for in cap design; and
Become familiar with various geotechnical considerations that must be addressed as part of the cap design such as bearing capacity/slope stability, edge effects/overlap requirements, liquefaction, consolidation, and vertical migration of cap materials.

Intended Audience

This course is intended primarily for civil and environmental engineers.

Benefit to Attendees

Attendees of this course will obtain practical knowledge pertaining to in-situ capping as a remedial alternative, which is useful for environmental professionals who have been, or will be, tasked with evaluating various remediation strategies for a contaminated sediment site.

Course Introduction

Contaminated sediments pose serious risks to human health and the environment, and therefore have received significant regulatory attention at the local, State, and Federal levels in recent years. Options commonly considered for remediation of contaminated sediment sites include monitored natural recovery (MNR), in-situ capping, and environmental dredging. The focus of this course will be to provide the attendee with an introduction to in-situ capping as a cleanup strategy for contaminated sediment sites. For the purposes of this course, in-situ capping refers to the placement of a subaqueous covering or cap of clean material over contaminated sediment that remains in place.

Course Content

The focus of this course will be to provide the attendee with an introduction to in-situ capping as a cleanup strategy for contaminated sediment sites. The course is offered within the context of guidance provided by the Environmental Protection Agency (EPA) for sites regulated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) programs, and cap design is presented based on guidance for in-situ subaquous capping of contaminated sediments developed by EPA. You are required to study select chapters from two EPA guidance documents in the order indicated below. The first document provides an introduction to fundamental concepts, while the second document focuses on principles of in-situ cap design.

Chapter 5 of “Contaminated Sediment Remediation Guidance for Hazardous Waste Sites,” 17 pages, PDF file.
Chapter 3 of “Guidance for In-Situ Subaquous Capping of Contaminated Sediments,” 25 pages, PDF file.

The contents of these materials are consolidated in one pdf file:

Chapter 5. In-Situ Capping & Chapter 3. In-Situ Cap Design

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

Physical removal of contaminated sediment (either through dredging or excavation) has been the selected remedial strategy at more than 100 Superfund sites across the United States. However, physical removal can often be cost prohibitive, technically infeasible, and may result in unnecessary damage to benthic populations. At many sites, in-situ capping has served as the primary approach for contaminated sediment, and at other sites is has been combined with sediment removal and/or monitored natural recovery. The focus of this course will be to provide the attendee with an introduction to in-situ capping as a cleanup strategy for contaminated sediment sites. Accordingly, this course will explore several aspects of in-situ capping as a remedial strategy, including:

a. Advantages and limitations of in-situ capping over other remedial approaches.
b. The primary functional components of caps.
c. How the physical environment at a contaminated sediment site plays a role in the development of its design.
d. General steps for in situ cap design.
e. Considerations in the identification of capping materials.
f. Geotechnical considerations that must be addressed in cap design.
g. Typical methods of placement of capping materials.
h. Objectives and considerations for performance monitoring of in-situ caps.

Related Links

For additional technical information related to this subject, please visit the following websites:

a. Palermo, M., Maynord, S., Miller, J., and Reible, D. 1998. “Guidance for In-Situ Subaqueous Capping of Contaminated Sediments,” EPA 905-B96-004. Great Lakes National Program Office, Chicago, IL.

b. Palermo, M. and D. Reible. 2007. The Evolution of Cap Design. Proceedings, World Dredging Congress WODCON XVIII, Orlando, FL, May 27-June1, 2007

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.