Dense non-aqueous phase liquids (DNAPLs) are denser than water and include chlorinated solvents such as tetrachloroethylene and trichloroethylene.

Dense, Nonaqueous-Phase Liquids (DNAPLs-4)
Section 2 (Overview of the DNAPL Problem)
This section presents an overview of the DNAPL problem, a general description of DNAPL flow in the subsurface, and describes why conventional approaches to characterizing DNAPL site can be ineffective.

Integrated DNAPL Site Characterization (ISC-1)
Section 2.1; Section 2.2; Figure 2-1; Figure 2-2; Section 2.3.1; Section 2.3.3; Section 2.3.2; Section 2.3.6; Section 2.3.7; Section 2.3.8; Section 2.4; Table 2-1; Section 3.1; Section 4.2.6; Section 4.7.3; Table D-7
This document synthesizes the knowledge of DNAPL site characterization and remediation and provides guidance on simultaneous characterization of contaminant distributions, hydrogeology, and attenuation processes.

Overview of In-Situ Bioremediation of Chlorinated Ethene DNAPL Source Zones (BIODNAPL-1)
Section 2; 3.1; Figure 2-6; Figure 2-7; Table 2-1
These sections introduce biodegradation and the fundamental principles underlying in-situ bioremediation (ISB) of DNAPL source zones, a description of the mechanisms of ISB, a discussion of the approaches of ISB of DNAPL source zones and the advantages and limitations, and the development of a conceptual site model (CSM) as the first step in assessing the applicability of ISB at a DNAPL site.