The U.S. Navy Region Southwest received the prestigious FY 2016 Chief of Naval Operations Environmental Award for the Environmental Restoration, Installation category for the design-build of remediation systems for volatile organic compound (VOC)-contaminated groundwater, soil gas, and indoor air at Naval Base Point Loma in California. Tetra Tech is proud to have contributed to the success of this project and to have supported the Navy in protecting human health and the environment.

The Navy, Tetra Tech, and other consultants collaborated to develop an innovative, sustainable, and accelerated approach to clean up legacy VOC contamination that posed a risk to personnel. Remedial actions included installing a soil vapor extraction system for soil gas, enhanced anaerobic bioremediation system for groundwater, and vapor intrusion mitigation measures for indoor air. While designing and implementing the remediation system, the Navy and its contractors worked quickly to reduce contamination to minimize disruption to Navy operations.

Tetra Tech supported the Navy by providing a state-of-the-art vapor intrusion mitigation system to ensure indoor air contamination was reduced efficiently and rapidly. We designed and installed an innovative mix of two vapor intrusion mitigation measures to provide extra protection: a sub-floor ventilation system to remove and treat VOC vapors, and vapor intrusion entry location sealing to eliminate migration of remaining vapors. The sub-floor ventilation system uses a targeted extraction system connected to a 110-volt treatment system installed in an oversized closet to minimize visual impact and noise.

Since the vapor intrusion mitigation system began operating in February 2016, it has remained operational for more than 99 percent of the time. Indoor air quality has been reduced below U.S. Environmental Protection Agency action levels, and all workers have been able to reoccupy vacated offices. Our team continues to monitor indoor air quality at the site.

Congratulations to the Navy, our team, and all contributors for this project’s successful resolution and continued success.