Landscaping of the 100-acre landfill area on the southwest corner of Alameda Point is nearing completion. The seeding of the landfill site with flowering native grasses is almost ready to begin. Contouring of the site is complete. Stabilization of the shoulder around the wetland area is complete. Placement of the final soil cover is underway.
The contouring of this industrial landfill site was completed on August 16, 2013. Approximately one-third of the contouring, or base layer, soil is clean soil recycled from Seaplane Lagoon dredging. The recycled soil stock was quickly exhausted, along with soil recycled after removing some of the berms and high areas. More than half of the base layer – 193,000 cubic yards – is soil barged in from Decker Island in the Sacramento River.
This contouring phase, which began in January of 2013, created the base layer with a specially-engineered slope. It was then scanned for radiation using scanners towed by a small vehicle, even though the site had been surveyed for radiation prior to placing the base layer.
Placement of the plastic biobarrier (see photo below) and the final soil cover using soil barged in from Decker Island began on August 19, 2013. The biobarrier is a plastic mesh that is designed to discourage burrowing animals from coming into contact with the waste area. The biobarrier installation is over 90% complete as of week #38 (October 24, 2013). The final two-foot soil cover is over 60% complete. The final soil cover includes six inches of soil amended to promote growth of vegetation.
The soil stabilization and drainage work on the shoulder around the wetland area is also completed. It includes native rye grass seeding, a jute mesh cover, and a silt fence. Some of the rye grass has already started to sprout.
New monitoring wells will be installed starting in late November.
Hydroseeding of the site with an assortment of California native grasses will begin in late November or early December.
In 2014 the old culvert connecting the north side of the wetland with San Francisco Bay will be replaced with a new culvert.
Fifty tons of old fence and metal have been recycled. The temporary work fence will be removed at the end of the job. The methane gas vents will be short and virtually unnoticeable (see photo below). Due to the age of the landfill and the fact that very little organic waste was deposited there, the methane gas produced is minor and will not require the 10-foot tall vent stacks proposed in an earlier workplan.
This site, along with adjacent land, will be transferred to the U.S. Department of Veterans Affairs in late 2013 or early 2014.
Source: The information in this update was gathered from the weekly progress reports for Installation Restoration Site 2 Remedial Action at Alameda Point. The progress reports are posted on the Envirostor website maintained by the California Department of Toxic Substances Control (DTSC). The source for all photos in this update, unless otherwise credited, is DTSC.