In 1993, the Department of Defense (DOD) funded the Advanced Alternative Technology Development Facility (AATDF) to advance innovative technologies for the remediation of DOD facilities. One objective of AATDF is to assist in the commercialization of remediation technologies by disseminating information on the technologies to potential users in the DOD and related communities. As part of this technology commercialization effort, DOD/AATDF has prepared this Technology Practices Manual (TPM) for Surfactants and Cosolvents to assist in the evaluation and appropriate application of surfactant­ and cosolvent­based flushing technologies for the remediation of subsurface nonaqueous phase liquid (NAPL) contamination. This chapter presents the objectives, organization, and limitations of the manual.

1.1 Objectives of This Technology Practices Manual

This manual has been prepared by DOD/AATDF to assist with the evaluation and potential application of surfactant/cosolvent flushing for the remediation of subsurface contamination. The target audience for the TPM is decision makers involved in the selection and implementation of remediation projects. These decision makers include DOD environmental staff, consultants and contractors, and regulators. The TPM also is designed to support those designing and implementing surfactant/cosolvent flushing systems. The manual provides background information on subsurface remediation and surfactants/cosolvents to assist those with a mixed or limited knowledge of remediation technologies. However, it is not a complete textbook, and some background on these subjects is helpful. The manual is designed so that those familiar with subsurface remediation can quickly find answers to their specific questions regarding the use of surfactants and cosolvents.

The more specific objective of this manual is to provide the reader with the following:

1.2 Organization of the Manual

This manual is being prepared in two editions. This First Edition is intended to fill a gap in readily available, objective information on the use of surfactants and cosolvents. It contains the most current information available through mid­1996. A number of field tests of surfactants and cosolvents are scheduled for 1996 and 1997; however, the results of these tests were not available for incorporation into the First Edition. A Second Edition will be prepared in late 1997 to incorporate these field test results.

Figure 1-1 provides a flow chart of the TPM. This chart can be used as a guide to reading the manual. Three suggested reading patterns are presented. The first is for the reader who has a limited background in NAPL fate and transport or surfactants/cosolvents and who is planning on implementing a surfactant/cosolvent flushing project. These readers should read the entire manual. Readers with a stronger background in NAPL fate and transport but not in surfactants/cosolvents, who are planning to implement a project, could skip Chapter 3. The reader only interested in a preliminary evaluation of the applicability of the technology could read Chapter 1, Chapter 2, Section 5.1, and Chapter 6.

To assist readers in finding the most appropriate information for their needs, each major section begins with a brief discussion of that section's relevance to a reader's particular interest and the key concepts presented in the section. The flow chart of the manual (Figure 1-1) can also assist readers in selecting the sections of the manual that are of most interest to them. To assist the reader in locating specific information, Table 1­1 lists common questions and where to look in the manual for answers.

1.3 Limitations of the Manual and Disclaimer

This manual is not intended to be a design manual. At this point in the application of surfactant/cosolvent technologies, there is insufficient field experience from which to produce a design manual. Likewise, this manual is not a research document or textbook. Although the manual summarizes some of the latest research and field applications of surfactants and cosolvents, the intended audience is the field practitioner and not the researcher. Consequently, the language and level of detail provided here may not satisfy the needs of vigorous research. References are provided so that interested readers can investigate the current research on surfactants and cosolvents.

Surfactants and cosolvents can be used to remediate excavated soils through soil washing processes. They also have been applied to soils in an effort to enhance bioremediation. These applications of surfactants and cosolvents are beyond the scope of this manual, although the general discussion on the mechanisms of surfactants and cosolvents may be applicable. This manual is limited to the application of surfactants and cosolvents for subsurface remediation.

Finally, DOD/AATDF wants to make it clear that it is the sole responsibility of the reader to appropriately apply these technologies. DOD/AATDF, the authors, and reviewers take no responsibility for the application of the technologies described in this manual.

Figure 1-1

Table 1-1
Locating Guide for Common Questions
Common Questions Reference
What is a surfactant? Section 4.1
What is a cosolvent? Section 4.2
What are the mechanisms by which these chemicals remove NAPLs? Section 2.2 and 4.1
For what types of contaminants is this technology effective? Section 2.4
What are the hydrogeologic limitations of the application of these technologies? Section 2.4 and 5.1
What are the typical costs of these technologies? Section 2.8 and 6.3
How long do these technologies take to implement? Section 2.5 and 5.1
To what extent can these technologies remove contaminants? Section 2.6 and 2.7
Are there any adverse environmental impacts of the use of these chemicals? Sections 4.4
Are these technologies proprietary? Section 2.2
Are there any regulatory or public perception constraints on the use of these technologies? Section 5.1 and 5.5
What types of permits must be obtained to use these technologies? Section 5.5.4
What is the current status of surfactant and cosolvent in-situ flushing technologies? Chapter 2.3
What extent of laboratory testing is required to implement these technologies? Section 5.3
How is the specific chemical solution selected? Section 5.1.4 and 5.3
What extent of field testing is required to implement these technologies? Section 5.5
What is the most appropriate niche for these technologies? Section 2.4 and 5.1

Forward to Chapter 2