Client
Exxon Mobil Corporation
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Location
Mulberry, Florida
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Key BCI Staff
Ted Smith, PG, CPG
Carl Christmann, PE
Les Bromwell, ScD, PE
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Project Costs
$4 million
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Start Date
1997
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Completion Date
2006

Scope

The ElectroPhos site is a former elemental phosphorus production facility located near Mulberry, Florida.  The ElectroPhos facility began operation in the 1950s and produced elemental phosphorous until 1983, when operations were suspended. Elemental phosphorous was produced at the facility by electro-arc reduction of low-grade phosphate ore from nearby mining operations.

Due to concerns by the Florida Department of Environmental Protection (FDEP), BCI was retained to assess ground water and surface water conditions to determine impacts by phosphorus from former phossy waste ponds on the property.  An extensive contamination assessment, risk assessment, and remedial alternatives analysis was completed between 1997 and 2001. The assessment included installation of   numerous monitor wells into the surficial and intermediate aquifers, collection and analysis of ground water and surface water samples, and evaluation of contaminant impacts.

Following the assessment, BCI designed and managed the construction of a new containment system for the site, including construction of a soil-bentonite slurry wall and HDPE cap system surrounding the former phossy ponds.  The slurry wall was keyed into a low-permeability soil layer at depths of approximately 40 feet to 62 feet below grade.  The slurry wall was constructed by the slurry trench method, and had a minimum width of 2.5 feet over a length of approximately 6,000 feet. 

The project involved significant health and safety issues, and required a Health & Safety Plan to address potential site worker exposures to elemental phosphorus and associated compounds throughout the duration of the project. Following construction, BCI conducted regular ground water and surface water monitoring to verify performance of the site closure.