An Assessment of Aquifer/Well Flow Dynamics: Identification of Parameters Key to Passive Sampling and Application of Downhole Sensor Technologies
ER-1704
Objective
Long-term monitoring (LTM) costs make up a substantial percentage of environmental restoration budgets for both government agencies and the private sector. A substantial part of LTM costs are costs associated with groundwater sampling and analysis. One promising cost-saving strategy is the replacement of traditional groundwater sampling approaches by a combination of passive sampling devices and in-situ sensors. However, regulatory and operational acceptance of changes in groundwater sampling methodologies is conditional on both laboratory and field validation of the methods and an in-depth understanding of how such methods represent groundwater chemistry.
The objective of this project is to develop a comprehensive understanding and description of how contaminant concentrations measured in a well using either passive sampling devices or in-situ sensors relate to contaminant concentrations in the surrounding formation. The research will elucidate the relationship between solute concentrations in wells and in the surrounding formation, thus providing the understanding and documentation necessary for efficient and cost-effective application of alternative sampling and monitoring strategies.
Technical Approach
Researchers first will formulate a comprehensive conceptual model for flow and transport into and around a well that incorporates all relevant physical properties and processes. Based on this conceptual model, laboratory experiments will be conducted in two-dimensional and three-dimensional sand-tank physical models with a focus on providing experimental data allowing for numerical model development and calibration. Researchers will then apply numerical models of flow in and around a well to the simulation of the laboratory experiments. These models again will be based on the conceptual model. These efforts will enhance understanding of the experimentally observed phenomena, as well as establish and sharpen the ability to accurately predict flow and transport into and around a well. Field work will include experiments using both passive and active sampling methods to evaluate the field-based predictive capability of the models.
Benefits
Establishing a solid scientific basis for non-purge groundwater monitoring will yield cost savings in both short-term and long-term time frames. Cost-saving approaches in the short term are expected to be passive groundwater sampling, where water samples are collected in an expedited fashion and analyzed by traditional methods. This approach is currently approved largely on a case-by-case basis. Cost saving is achieved through avoidance of purge water handling and disposal and reduced labor. Long-term savings will be achieved as sensor technologies are developed and perfected for specific constituents of environmental concern. Sensor approaches may avoid laboratory analysis to a large degree, which would save additional resources. (Anticipated Project Completion - 2012)
Points of Contact
Principal Investigator
Mr. Sanford Britt
ProHydro, Inc.
Phone: 585-385-0023
Fax: 585-385-1774
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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- Model/Software - Computer programs and applications available for download.
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