Development and Validation of a Quantitative Framework and Management Expectation Tool for the Selection of Bioremediation Approaches at Chlorinated Solvent Sites
ER-201129
Objective
The objective of this project is to develop a quantitative framework that will aid remedial project managers (RPMs) and site managers in evaluating and selecting the most appropriate biologically mediated remediation strategy for a given chlorinated solvent site. The quantitative framework will involve the use of refined flow charts coupled with decision-making matrices to guide the user in the evaluation of remedial alternatives. The deliverable will be an easy to apply management expectation tool (i.e., decision support software) that can be used to integrate the impact of quantifiable biogeochemical parameters on bioremediation of chlorinated ethenes. Demonstration/validation efforts at Department of Defense (DoD) sites with different biogeochemical settings will focus on decision-making matrices to determine if monitored natural attenuation (MNA), biostimulation, biologically mediated abiotic reductive dechlorination, or bioaugmentation is the most appropriate remedy based on specific site conditions. Detailed analyses will demonstrate capital investment and operations and maintenance (O&M) savings.
Technology Description
The framework will be developed in a fashion similar to the scoring system designed by Dr. John Wilson and Mr. Todd Wiedemeier to assess the likelihood of in situ reductive dechlorination (EPA, 1998). The scoring system developed by Wilson and Wiedemeier then was based on the relative importance of measurable geochemical parameters on the efficacy of biological processes for contaminant detoxification. Each parameter was assigned a scoring value, a.k.a. impact value, based on its relative importance or impact in relation to biologic and abiotic contaminant transformation. The decision-making framework to be developed in this project will use this bioattenuation framework as a starting point. New information about processes, organisms, and genes involved in chlorinated ethene detoxification will be incorporated into the decision-making framework. For example, genes that are linked with vinyl chloride reductive dechlorination to ethene are now known. Also, it is understood that the formation of sulfide from the biological reduction of sulfate is an important process contributing to biologically mediated, abiotic transformation reactions. In addition, many new techniques have been developed and validated to assess geochemical conditions in the subsurface and obtain quantitative microbiological data. Two modules also will be added to the updated MNA protocol, aiding and supporting the decision to biostimulate and/or bioaugment.
Benefits
The lack of a systematic approach for determining the most efficient bioremediation approach results in unnecessary financial and environmental costs. Furthermore, aquifer amendments, such as substrates and inocula, can result in undesirable secondary impacts to groundwater quality such as pH changes, metal dissolution, aquifer clogging, and formation of (greenhouse) gases. Conceding a quantitative multiplier to parameters on which decisions can be based will provide a systematic approach for decision making. Such an approach would represent a major advancement over the current practice that uses empirical information, which is generally not based on quantitative data and scientific understanding. Application of the management expectation tool can minimize detrimental environmental impacts associated with more invasive bioremediation treatment options, in addition to reducing both capital and O&M costs to DoD. (Anticipated Project Completion - 2014)
Points of Contact
Principal Investigator
Ms. Carmen Lebr�n
Naval Facilities Engineering Command Engineering Service Center
Phone: 805-982-2907
Fax: 805-982-4304
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.