In-Situ Bioremediation of MTBE in Groundwater
Abstract
This innovative groundwater treatment demonstration involved the design, installation, and optimization of a large-scale biobarrier for the in situ treatment of groundwater impacted by methyl tertiary butyl ether (MTBE) and other dissolved gasoline components. It was implemented at the Naval Base Ventura County, Port Hueneme, California to prevent further contamination of groundwater by MTBE leaching from gasoline-contaminated soils (see Figure 1). The Port Hueneme site is well-known because the dissolved MTBE plume is already 5,000 ft long and 500 ft wide and the base has hosted many small-scale MTBE treatability studies in recent years. The results of this demonstration are of significant benefit to the environmental profession for several reasons. It is the first demonstration project to document a full-scale, cost-effective remedy for in situ treatment of an MTBE-impacted aquifer. Remediation via engineered in situ biodegradation was thought to be an unlikely candidate just a few years ago. This project demonstrates that MTBE-impacted groundwater can be remediated in situ via engineered aerobic biodegradation under natural-flow conditions. The installation and operation costs associated with this innovative biobarrier system are 66% lower than those of the existing large-scale pump and treat system that was also implemented for containment of the dissolved MTBE plume at Port Hueneme. It has been suggested that aerobic MTBE biodegradation will not occur, or will not be effective, in mixed MTBE-benzene, toluene, ethylbenzene, and xylenes (BTEX) dissolved plumes. This project demonstrates that MTBE-impacted groundwater can be remediated with BTEX components via aerobic biodegradation in a mixed MTBE-BTEX dissolved plume. This system has achieved an in situ treatment efficiency of >99.9% for dissolved MTBE and BTEX. Samples collected from down-gradient monitoring wells typically now contain <5 ug/L MTBE and nondetectable levels of BTEX components.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2003
- Accession Number
- ADA607309
Entities
People
- Cristin Bruce
- Karen Miller
- Paul Johnson
Organizations
- Naval Facilities Engineering Systems Command