Shoreline contamination barrier under construction at NW tip of Alameda Point

The Navy began embedding a steel barrier along several hundred feet of the western shoreline of Alameda Point during the week of August 18. The purpose of the barrier is to contain contaminated ash and burn waste material that was bulldozed into the Bay some 60 years ago and is now overlain with silt. The area is where the Navy burned various waste materials.

Three of the waste isolation cells under construction at northwestern tip of Alameda Point.  A total of 15  cells, each one separated by a wall behind the face of the barrier, will be constructed here.
Three of the waste isolation cells under construction at northwestern tip of Alameda Point. A total of 15 cells, each one separated by a wall behind the face of the barrier, will be constructed here.

The containment system is called a waste isolation barrier. It consists of 35-foot-long interlocking steel pilings that are hammered into the ground with a hydraulic vibrator suspended from a crane cable. Perpendicular steel walls behind the barrier add stability. The final elevation of the top of the waste isolation barrier will be approximately 10 feet above mean sea level.

A worker guides one of the galvanized steel pilings into place as crane operator maneuvers.
A worker guides one of the galvanized steel pilings into place as crane operator maneuvers.

Tests around the area were conducted in 2010, 2011, and 2012 to determine if any of the chemicals in the burn residue were entering San Francisco Bay.  None were found to be entering the Bay.  Nevertheless, the Burn Area’s proximity to the Bay requires that the contaminated waste either be removed or permanently isolated. Removing all of the waste from under the shoreline would have cost $40 million. The containment system costs $13 million.

Piling being slowly driven into the ground by a hydraulically operated vibratory hammer.
Piling being slowly driven into the ground by a hydraulically operated vibratory hammer.

The construction of the shoreline waste barrier is part of a larger Navy cleanup project on the adjacent 37 acres, called Site 1, which was once used as an underground waste disposal area. Much of the area is now covered by runway pavement that will remain in place. The entire 37 acres right up to the steel barrier will be covered with three feet of clean soil and seeded with native vegetation. A small wetland area will also be created along the shoreline.

Site 1 cleanup project with crane.  Oakland Estuary in the foreground and San Francisco in the background.
Site 1 cleanup project with crane. Oakland Estuary in the foreground and San Francisco in the background.

When completed early next year, the area will be suitable for passive recreational use, including the Bay Trail.

The work can be observed from the Oakland side of the estuary at Middle Harbor Shoreline Park right next to the cranes.

Originally published in the Alameda Sun.

Background information can be found in this post from April 2013.

More photos and a diagram below 

Waste isolation barrier, looking east

Interlocking pilings closeup

Waste isolation barrier will have 12 more cells to the right when completed.
Waste isolation barrier will have 12 more cells to the right when completed.
Diagram of shoreline waste isolation barrier at northwestern tip of Alameda Point.  Navy diagram.
Diagram of shoreline waste isolation barrier at northwestern tip of Alameda Point. Navy diagram.

Site 1 waste isolation barrier under construction

Cleanup plan changes at waste burning area

Northwest tip of Alameda Point.  Waste burning area is immediately to the right of trees.  Port of Oakland is in background.
Northwest tip of Alameda Point. Waste burning area is immediately to the right of trees.  Port of Oakland is in background.

It was the 1950s, before the environmental movement of the 1970s and the laws that followed in its wake.  Hauling waste materials out to the western shoreline of Alameda Point to be burned and bulldozed into the Bay was not considered irresponsible.  The “Burn Area,” as it is called, lies next to the shore near the entrance to the Oakland Estuary.

Burn Area on Site 1.  San Francisco Bay to the left.  Oakland Estuary to the north.
Burn Area on Site 1. San Francisco Bay to the left. Oakland Estuary to the north.

By 2009, the Navy was ready with a plan to finally remove several acres of contaminated Burn Area soil and haul it away.  In 2010, testing by the cleanup contractor preparing to do the work, however, revealed additional burn residue that extends over a longer area and under the shoreline slope.  The new information triggered a complete re-evaluation of the plan.

Excavation and removal at the greater depth and under the shore would drive the cost up from the original $5 million to $40 million.  Fortunately for the Navy, a new and lower cost option became available just as the Navy and regulatory agencies were gathering more soil and groundwater data and discussing options.

In 2011, the US Army Corps of Engineers approved a shoreline steel containment system called an “open cell vertical confined disposal facility.”  Primarily used for harbor and waterway reinforcement and as a containment area for dredge sediment, the system is also suitable for permanently isolating and containing the toxic burn material along several hundred feet of Bay shoreline.  This option will cost $13 million.

Open cell sheet pile containment system under construction at Dutch Harbor, Alaska.  Photo source:  US Army Corps of Engineers 2011 report.
Open cell sheet pile containment system under construction at Dutch Harbor, Alaska.  The same system is proposed for the Alameda Point Burn Area.  Photo source: US Army Corps of Engineers 2011 report.

The Navy calls the open cell system a “waste isolation bulkhead.”  It consists of a wall of interlocked steel plates embedded in the earth along the shoreline.  Perpendicular steel walls extend toward the shoreline to form cells, or compartments, and provide anchorage.  The absence of welding to hold the system together allows it to flex without failing and eliminates the problem of welds corroding.

Tests around the Burn Area were conducted in 2010, 2011, and 2012 to determine if any of the chemicals in the burn residue were entering San Francisco Bay.  None were found to be entering the Bay.  Nevertheless, the Burn Area’s proximity to the Bay requires that it either be removed or permanently isolated.

The Burn Area is located on the 37-acre Site 1 cleanup area.  The site includes about a half dozen unlined underground pits that were used for waste disposal and are now partially covered by runway pavement.

Site 1 landfill map.  Area 1b is the Burn Area as it was originally configured.
Site 1 landfill map. Area 1b is the Burn Area as it was originally configured.  Click to enlarge.

Cleanup of a solvent plume on Site 1 that posed a potential threat to the Bay took place last year.  Previous cleanup on the site included removal of debris and soil contaminated by radium-226 used in painting luminescent aircraft dials.

When the Navy is finished with the Burn Area bulkhead barrier, the Burn Area will again be tested for radiological contamination.  All 37 acres of Site 1 will then be covered by at least two feet of clean soil and seeded with native grasses.

Site 1 will be available for passive recreational use as part of the proposed 147-acre regional park along the northern shoreline.  Site 1 will be part of the final conveyance of land to the city slated for 2019.  The VA’s property is adjacent and to the south and east.

The Navy’s project manager along with the cleanup contractor for Site 1 will be present at a special public meeting to answer questions and take comments on the new proposed plan for the Burn Area.  The meeting is on April 9 at the Alameda Main Library, 1550 Oak Street, from 6:30 pm to 8:00 pm.

Originally published in the Alameda Sun.

Further Reading on the Navy’s Burn Area Study

The Navy’s recently-completed soil and groundwater study for the Burn Area is called a Focused Feasibility Study (FFS) and is located on the state Envirostor website.

The FFS is very large and is divided into parts.  Recommended parts to look at first:

Part 1, Part 3 (cool maps), Part 4 (mostly raw data, but has trench photos), and Part 8 (descriptive letters from PND Engineers that own the patent on the open cell system, and all the comments by the regulatory agencies and the responses to comments.)  Part 5 has a lot of technical data and description of the groundwater model in relation to the Bay.

Reference material on the open cell barrier proposed for the Burn Area:

US Army Corps of Engineers 2011 report on the use of the Open Cell Sheet Pile Containment System for contaminated dredge material.

Overview of the Open Cell Confinement Disposal Facility system by PND Engineers.

2012 report to the Alaska Legislature on the Open Cell system.

Image highlights from the Focused Feasibility Study for the Site 1 Burn Area

Click on images to enlarge.