ITRC Implementation Workshop In Situ Bioremediation of Chlorinated - - PowerPoint PPT Presentation

October 22, 2008 Phoenix, AZ

In Situ Bioremediation of Chlorinated Ethene: DNAPL Source Zones Naji Akladiss

ITRC Implementation Workshop

Overview

• Tens of thousands of DNAPL source zones exist in federal and private sites
• Current technologies used to remediate DNAPL require introduction of energy

(e.g. Steam or heat), fluids ((Surfactants) or chemical (KMnO4) primarily to mobilize DNAPL so that it can be recovered.

• ISB of DNAPL uses micro-organisms – which can proliferate and degrade

DNAPL without mobilization and provide a far more efficient, effective and less costly remediation alternative.

• Regulators and practitioners need to understand the proper application and

limitations of BioDNAPL

• Monitoring the removal of mass in a DNAPL Source Zones uses groundwater

chemical parameters – not contaminant concentrations in groundwater.

• May not see immediate results. Improvement may occur within months of the

application of the technology.

Tech-Reg Content

• In Situ Bioremediation of DNAPL is;

– Removal of DNAPL source mass by dissolution at the DNAPL/water interface and destruction of dissolved chlorinated organics using in situ bioremediation

• The Tech-Reg

– Contains a decision tree beginning on Page 20 (Figure 2-5) that describes the major decision within the design and operational monitoring steps for ISB of DNAPL Source Zones – Describes the advantages and limitations of using ISB of DNAPL source zones. – Describes the monitoring requirement for the process, the performance and compliance – Describes the parameters practitioners and regulators should consider when optimizing the performance. – Describes how ISB of DNAPL source zones can accelerate the cleanup of the site – Refers to case studies where ISB of DNAPL has been applied

Steps to Achieve Impact

• The regulatory programs should concur with the guidance and

notify the practitioners that they are receptive to properly designed remediation plans incorporating ISB of DNAPL

• Practitioners should use the Tech-Reg as a guide when

preparing remediation work plans and reference the Tech-Reg as the basis of their work plan.

• Practitioners following the Tech-Reg can demonstrate that

destruction of DNAPL using ISB at the source zones can accelerate the overall site cleanup and thereby reduce chronic exposure and Regulators must acknowledge that DNAPL mass reduction will shorten the overall remediation time.

• RPs can reduce there lifecycle liability by using destructive

technologies like ISB of DNAPL source zone

Where Tech-Reg Will Provide Impact

Feel comfortable that ISB of DNAPL is applied properly and the outcome does not increase the toxicity of the contaminants or long term risk. The application is applied and designed according to a guidance developed by states along with practitioners Community Lower up-front costs traded off for long term monitoring Develop remediation plans including ISB of DNAPL source zones that state regulators will accept and be familiar with. Practitioners Effective reduction of mass and long term risk Use the performance metrics described in the document to understand the benefit of ISB at their site Regulators Shorter remediation time frame / reduce lifecycle cost / reduce the long term potential risk As a guide to evaluate the merits of ISB of DNAPL at a source zone and assess reducing their long term environmental liability Site owners BENEFIT TO BE RECEIVED BY USERS INTENDED USE OF TECH-REG EXPECTED USER

We Use the Tech-Reg

Baseline geochemistry and hydrogeology sampling Remedy selection and initial design Design support and pilot study sampling Final design and full-scale system construction Full-scale system operation Remedy complete Key system operating parameters— TOC, pH, VOCs, ethene, methane Yes Yes No No Continue operation Modify the operation Are system variables within accepted range? Are key design assumptions validated? Yes No Revise design Are project objectives achieved? Troubleshooting based on expanded variables list, which may include expanded geochemistry, microbial population characterization, functional enzyme analysis, and

• ther analytes. See Table

5.1 for further explanation.

Maine has received a proposal to incorporate ISB of DNAPL into a site remediation. The consulting firm referenced the Tech-Reg in the proposal. As a result, the State will refer to the Tech-Reg while reviewing the proposal.

Specific Implementation Target Ideas

• Nearly all military installations and DOE facilities encounter

DNAPL contamination. Feasibility studies should consider the use of ISB of DNAPL source zones thereby reducing costs, long term environmental liability, and risk

• Large manufacturing facilities can have extensive DNAPL

contamination and should consider this destructive technology.

• Universities with environmental curriculums should include the

guidance as a resource describing the application of ISB of DNAPL source zones

• The dry cleaning industry should universally consider ISB of

DNAPL especially at suburban sites.