Building 4 UST Removal and Site Restoration, Naval Amphibious Base (NAB), Coronado, CA.

This task order includes the removal of a newly discovered underground storage tank and associated sampling, reporting and disposal. A UST Closure Report was prepared, and the site was granted no further action status from the County of San Diego Department of Environmental Health.

During the redevelopment of former Building 4 at NAB Coronado, a previously unknown concrete underground storage tank (UST) was encountered. The former UST was used to store fuel oil that was used to heat the former Building 4. The scope of this project included the permitted removal of the UST and to restore the site to grade. A UST removal permit was obtained from the County of San Diego Department of Environmental Health (DEH). An Accident Prevention Plan and Site Safety and Health Plan were prepared and included an Activity Hazard Analyses and a Confined Space Entry Plan. A Work Plan was also prepared detailing the UST removal activities. A confined space entry was required to remove debris and clean the interior of the UST prior to the in-place destruction of the concrete UST, and its subsequent removal for concrete recycling.

A limited amount of petroleum impacted concrete and rinse water from the UST cleaning were removed from the site for disposal at an appropriate disposal facility under a non-hazardous waste manifest. The cleaned concrete was broken up on-site and hauled to a recycling facility where it was turned into road base. Since the bottom of the former UST was below the groundwater table, groundwater samples were collected under the direction of a DEH Inspector and analyzed at a certified laboratory under proper chain-of-custody protocol. Upon completion of the groundwater sample collection, the resultant excavation was back filled with clean pea gravel to within one foot of the original grade and capped with certified clean fill soil and compacted so building redevelopment could continue. Upon receipt of the final laboratory report, a UST Closure Report was compiled and submitted to DEH and the U.S. Navy requesting no further action status for the former Building 4 UST Site. DEH subsequently approved the report and granted no further action status for the site.