Field Demonstration of Propane Biosparging for In Situ Remediation of N-Nitrosodimethylamine in Groundwater
ER-200828
Objective
N-nitrosodimethylamine (NDMA) is a potent carcinogen and an emerging groundwater contaminant at a number of military and National Aeronautics and Space Administration (NASA) facilities that use or test liquid propellants. Contaminated sites include the Rocky Mountain Arsenal, Colorado; former Air Force Plant PJKS, Colorado; White Sands Missile Range, New Mexico; Aerojet Corp, California; Jet Propulsion Labs, California, and Edwards Air Force Base, California. The overall objective of this Environmental Security Technology Certification Program (ESTCP) project is to demonstrate and validate an in situ bioremediation approach for treating groundwater contaminated with low concentrations of NDMA. This technology entails distributing propane gas and oxygen in the subsurface to stimulate propanotrophs, a class of indigenous microorganisms that have been shown to rapidly degrade NDMA to innocuous products. One key question to be addressed is whether treatment levels of NDMA in the parts per trillion range can be achieved in situ using this approach. This technology is anticipated to be significantly less expensive than the current treatment technology, which is pump-and-treat with ultraviolet (UV) irradiation.
Technology Description
In this ESTCP demonstration, propane gas and oxygen will be applied in situ to NDMA contaminated groundwater. One of the advantages of this approach is that there are multiple ways to amend groundwater with these gases depending on site conditions, including vertical sparging wells or points, horizontal wells, bubble-free diffusion devices (e.g., in situ oxygen curtain [ISOC]), permeable treatment trenches, and groundwater recirculation systems with active gas injection. During this demonstration, we intend to use vertical sparging wells to distribute propane and oxygen to groundwater. This approach is mature, well suited to both shallow and deep sites, and expected to be widely applicable.
Benefits
There are presently no viable in situ biotreatment options for NDMA in groundwater. The compound is persistent in aerobic aquifers and appears not to be biodegraded during typical in situ anaerobic remediation approaches for chlorinated solvents (e.g., addition of lactate or other electron donors). At present, the most widely applied remedial technology for NDMA is pump-and-treat with UV irradiation. This technology is effective at removing NDMA to required regulatory levels (parts per trillion), but it is also very expensive, requiring both pump-and-treat infrastructure and banks of UV lights that require significant energy to reduce NDMA to required levels (approximately an order of magnitude greater energy demand than for water disinfection). The objective of this proposal is to demonstrate and validate an in situ bioremediation approach for NDMA in groundwater that has the potential to reduce remediation costs for NDMA at Department of Defense (DoD) and aerospace sites. (Anticipated Project Completion - 2011)
Points of Contact
Principal Investigator
Dr. Paul Hatzinger
CB&I Federal Services
Phone: 609-895-5356
Fax: 609-936-9221
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.