Metric Identification and Protocol Development for Characterizing DNAPL Source Zone Architecture and Associated Plume Response
ER-1612
Objective
Widespread use of chlorinated ethenes, such as trichloroethene (TCE) and tetrachloroethene (PCE), in dry cleaning and degreasing operations has led to groundwater contamination at thousands of industrial facilities and governmental installations. Most contaminant plumes at such sites emanate from aquifer regions containing dense nonaqueous phase liquid (DNAPL). Recent research has revealed that there is a strong link between source zone architecture (local-scale DNAPL distribution) and downgradient plume response to partial mass removal. As such, there is a need for systematic assessment of DNAPL architecture metrics and development of quantification methods based on field-observable parameters.
The objective of this project is to develop and demonstrate a comprehensive approach for field characterization of DNAPL source zones that quantifies the key features controlling plume response. Specific objectives include (1) identifying the most information-rich metrics for linking NAPL architecture to plume response, (2) developing and refining in-situ test methods and modeling tools that can be used to quantify identified metrics in targeted regions of the source zone, (3) integrating these metrics and tools with current characterization methods for an overall source zone assessment protocol, and (4) developing simplified models for predicting plume response.
Technical Approach
Influence of DNAPL Architecture on Distribution of Concentration in Down-Gradient Plume.
Previous research conducted under SERDP project ER-1293 suggested that features of a DNAPL distribution, such as ganglia-to-pool (GTP) ratio, may be of far greater importance for source zone remedy selection and analysis of technical feasibility and far easier to estimate in practice than the precise spatial distribution of the DNAPL saturations. While the GTP ratio has been demonstrated useful in the assessment and prediction of system behavior in simulated and laboratory experiments, no general guidance exists for its quantification in practice, nor is it clear that the GTP ratio is the most appropriate parameter to characterize long-term plume response to mass removal in the field. This project will integrate batch, column, and aquifer cell experiments with mathematical modeling and processing tools to identify and quantify features of the DNAPL architecture controlling the down-gradient plume response. The utility of the developed protocol and modeling tools will then be demonstrated in the field.
Benefits
This project will provide site managers and regulatory agency officials with an improved understanding of how plume response is coupled to DNAPL architecture. The suite of protocols and models developed can be employed for source zone characterization and remedy screening. Collectively, results will include key metrics for characterizing DNAPL source zone architecture, targeted methods for quantifying source architectural metrics, an integrated protocol for source zone characterization, and simplified modeling tools to assist site managers in source characterization and prediction of remedy performance. (Anticipated Project Completion – 2013)
Points of Contact
Principal Investigator
Dr. Linda Abriola
Tufts University
Phone: 617-627-3237
Fax: 617-627-3819
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.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.