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Braddock Cattle Dipping Vat Contamination Assessment - Duval County, FL
Project Type: Phase II ESA, Contamination Assessment Plan
Over 4,600 tons of soil and 1.3 M gallons of impacted groundwater were delineated. The Braddock Cattle Dipping Vat site is located in northwestern Duval County, Florida in a rural area beginning to undergo development as a planned mixed use community. The site is comprises mostly timberland and a small area that was formerly used agriculturally. The cattle dipping vat was built in the 1920s and used for a short period of time to eradicate the cattle fever tick in Florida.
An initial Phase II Environmental Site Assessment was conducted in November 2005 to identify the presence or absence of contaminants associated with the vat. The results of the Phase II ESA indicated elevated arsenic concentrations in soils and groundwater in the vicinity of the cattle dipping vat. ESI prepared the Contamination Assessment Plan in accordance with Chapter 62-770, F.A.C. and implemented an intensive Contamination Assessment from November through December 2005. The objectives of the Phase II ESA and Contamination Assessment were to delineate the vertical and horizontal extent of contamination in soils and groundwater from the existing cattle dipping vat.
ESI installed a total of 38 soil borings from ground surface to 40-feet below grade. Soil borings were installed by direct push technology and were mapped on-site using a Trimble GPS unit for more accurate soil boring locations. Soil borings were located at the grid nodal points using the centerline of the cattle dipping vat as the orientation baseline. ESI collected a total of 154 soil and 84 groundwater samples in order to delineate arsenical pesticide impacts. Results indicated arsenic impacts to on-site soils and groundwater exceeding applicable Cleanup Target Levels (CTLs). More than 4,600 tons of impacted soils and 1.3 million gallons of impacted groundwater have been delineated and an estimated cost proposal was drafted for the proper removal of the soils to be disposed of at an approved landfill facility and for active remediation of contaminated groundwater to achieve applicable CTLs.
The Contamination Assessment results identified arsenic soil and groundwater impacts within an area of 1.1 acres, with impacts to 40 feet below ground surface. ESI has produced a Remedial Action Plan that is designed to utilize source removal by excavation of impacted soils followed by injection of coagulant to immobilize arsenic concentrations in groundwater. Extensive pumping of groundwater through a network of dewatering well points and frac tanks will be performed to route groundwater through an activated alumina treatment media and microfilter before being discharged in the former source area.
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