Heavy Metals and Lead Remediation at Hunter's Point Naval Base

This heavy metals and lead remediation project was based out of a former Naval Shipyard. The Hunters Point Naval Shipyard, San Francisco, California was a large shipyard, repair facility, and optics coating facility for the United States Navy from the early 1900's until the late 1970's. In the past, non-soluble chemicals (i.e. heavy metals such as lead) was used for the repair and painting of ocean going ships, the coating of lenses for periscopes, as well as other visual aids. At that time, disposal was not regulated and subsequently many of the heavy metals bearing waste were disposed of in an open garbage dump located on the site. To reutilize the now defunct shipyard for commercial and residential use these areas are being excavated and the contaminated soils treated to remove hazards to humans.

The heavy metals and lead remediation treatment was specifically aimed towards lowering the lead concentrations through remediaton. The levels of contamination reached 160ppm leachable Lead. The target level for the Lead was set at <5 ppm as determined by the TCLP. Processing and testing were done in 1000-ton batches. In all but 2 of the tests ND (non-detect) results were attained, and the 2 tests that did not reach non-detect were below 1.0ppm, well within the target level of <5ppm.

Project Performance

A custom blending unit designed and built by Phoinix personnel was used in conjunction with a Power Trac screening unit for maximum efficiency in the stabilization of metals bearing soils. Using this method resulted in a well blended, screened product. The production rates for these Lead contaminated soils averaged 115 to 250 tons per hour. Production rates were restricted only by the ability to feed the screening plant, successfully treating 11,500 tons of soils in only 13 days.