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Soil and Groundwater Remediation at Pier A West, Port of Long Beach, CA

The Port of Long Beach acquired a 90-acre oil field and intended to develop the property for future beneficial use; however, the property had to be cleaned up before development. Oily wastes were buried in 19 sumps in the 1950s. Groundwater contaminated with chlorinated solvents and petroleum hydrocarbon compounds were found in two isolated plumes.

Accord was retained by the POLB to prepare a draft Remedial Action Plan for the site in 2006. In situ technologies, such as bio-augmentation and chemical oxidation (ChemOx), were considered for the long-term remediation. Work plans were developed to perform bench- and pilot-scale treatability studies. After reviewing the site characterization data, Accord identified several groundwater hot spots with high concentrations of vinyl chloride that would require prompt action before full-scale remediation could begin. Accord suggested several innovative approaches to mitigate the imminent threat. After several review discussions with RWQCB and DTSC, an interim source removal action was agreed to proceed.

Subsequently, Accord entered into a sub-consultant agreement and played a key role by producing an engineering design for the interim source removal action of soil and groundwater. The waste material in 19 sumps had to be removed, while the 2 groundwater hot spots had to be remediated to reduce the potential impacts of VOC emissions during the removal action. Max Pan led a team of Accord engineers and geologists to delineate each of the sump boundaries by trenching, sampling, and visual observation. He developed sump boundary drawings and was the principal author for developing the engineering specifications for sump excavation.

Parallel to the engineering design effort, David Cheng led a team of Accord scientists, engineers, and technicians in conducting a ChemOx Injection Pilot Test at the groundwater hotpots. The purpose of this test was two-fold: first, to verify the feasibility of implementing this technology and second, to reduce the mass of contamination at hot spots before the open excavations started. In order to remediate the contaminated clay layer that separated two groundwater aquifers, Dr. Cheng designed an innovative approach by using two types of ChemOx agents with distinctly different physical characteristics. One agent, sodium permanganate, was used in the upper aquifer, and a solution of ozone gas and hydrogen peroxide was injected into the bottom aquifer. The pilot treatment system was successfully constructed and operated by Accord personnel from May to September 2010. The hot spots were successfully minimized, and the field workers did not have to upgrade the Personal Protection Equipment to Level B. This project received a California 2009 Engineering Excellence Merit Award from the American Council of Engineering Companies (ACEC).

More pictures from this very important project