Direct-Push Optical Screening Tool for High-Resolution, Real-Time Mapping of Chlorinated Solvent DNAPL Architecture
ER-201121
Objective
Chlorinated solvents are among the most common organic contaminants detected in groundwater at Department of Defense (DoD) sites. The sources of these contaminants are often historical releases of dense nonaqueous phase liquids (DNAPL). Unfortunately, chlorinated solvent DNAPL source zones are difficult to locate using conventional subsurface characterization technologies. Laser-induced fluorescence (LIF) tools are currently available for real-time, high-resolution mapping of petroleum hydrocarbon and coal tar-based NAPL source zones. These LIF tools do not work with chlorinated solvent DNAPLs because chlorinated solvents lack the aromatic structure responsible for the laser-induced fluorescence in coal tars and petroleum hydrocarbons. The objective of this project is to demonstrate a new tool, referred to as the "DYE-LIF" optical screening tool, that extends the LIF technology to chlorinated solvent DNAPLs.
Technology Description
The DYE-LIF tool works by injecting fluorescing, hydrophobic dye through a small injection port located several inches below the detection window of a standard LIF probe as the probe is advanced into the subsurface. The injected dye partitions into the NAPL (if present) and fluoresces in the presence of a light source, allowing the same LIF tooling (lasers, optical reading and processing equipment) to be used to detect chlorinated solvent DNAPLs. Field demonstrations will compare results from the DYE-LIF tool with more conventional source zone characterization (e.g., detailed soil coring and NAPL testing using colorimetric dyes and via quantitative chemical analysis).
Benefits
Based on the number of chlorinated solvent DNAPL source zones likely present at DoD installations, the DYE-LIF could save DoD tens of millions of dollars in site investigation costs by providing a tool capable of rapid, high-resolution, real-time mapping of chlorinated solvent DNAPL source zones. Detailed characterization of the DNAPL architecture is critical for successful DNAPL source zone remediation as the effectiveness of remedial technologies is based on the ability to deliver remedial agents (e.g., chemical oxidants, microbial substrate) to portions of the aquifer where DNAPL is present. High-resolution mapping of DNAPL source zones could save DoD hundreds of millions of dollars in remediation costs by better focusing source zone remediation on the small portions of the aquifer containing DNAPL. (Anticipated Project Completion - 2014)
Points of Contact
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
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