Full-scale in0situ biobarrier demonstration for containment and treatment of MTBE

摘要

The Naval Facilities Engineering Service Center (NFESC), Arizona State University, and Equilon Enterprises HC are partners in an innovative Environmental Security Technology Certification Program cleanup technology demonstration designed to contain dissolved MWE groundwater plumes. This full-scale demonstration is being performed to test the use of an oxygenated biobarrier at Naval Base Ventura County, in Port Hueneme, California. Surprisingly, few cost-effective in-situ remedies are known for the cleanup of MTBE-impacted aquifers, and remediation by 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 through engineered aerobic biodegradation under natural-flow conditions. With respect to economics, the installation and operation costs associated with this innovative biobarrier system are at least 50 percent lower than those of a conventional pump and treat system. Furthermore, although it has been suggested that aerobic MTBE biodegradation will not occur in mixed MTBE-BTEX dissolved plumes, this project demonstrates otherwise. The biobarrier system discussed in this article is the largest of its kind ever implemented, spanning a dissolved MTBE plume that is over 500 feet wide. This biobarrier system has achieved an in-situ treatment efficiency of greater than 99.9 percent for dissolved MIBE and BTEX concentrations. Perhaps of greater importance is the fact that extensive performance data has been collected, which is being used to generate best-practice design and cost information for this biobarrier technology.