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Hazardous Waste Cleanup: Occidental Chemical Corporation in New Castle, Delaware

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This former chlorine manufacturing facility is approximately 38 years old and is located on the banks of the Delaware River, along River Road, just south of Red Lion Creek. The facility is located in a heavily industrialized area, and is situated approximately three miles northwest of Delaware City, Delaware.

Cleanup Status

The final remedy has been selected for this Facility and construction of the various final remedy components will begin shortly. EPA released its Final Decision and Response to Comments for the selected cleanup approach for the Facility on December 8, 2011. The selected remedy emphasizes source removal and source control through excavation, consolidation and capping of soils and sediments with concentrations of contaminants above cleanup levels. The primary sources of groundwater contamination are being and will continue to be controlled by barrier walls and free product removal, and targeted in-situ treatment will be used to address areas outside of the barrier wall containment areas to restore groundwater to drinking water standards. Certain institutional controls will be continued and additional institutional controls will be implemented to prevent current and potential future exposure to contamination and any activities that would impair the integrity of the remedy.

In June 2012, EPA completed negotiations and entered into a RCRA Section 3008(h) consent order with Occidental Chemical Corporation. This consent order requires Occidental to implement the final remedy (or corrective measures) selected by EPA for the New Castle facility. A Corrective Measures Implementation (CMI) Work Plan describing the overall strategy for remedy construction, including a schedule and sequence of remedy design documents, was developed in coordination between EPA, Delaware Department of Natural Resources and Environmental Control (DNREC) and Occidental and approved by EPA on June 3, 2013. Between 2013 and 2014 EPA worked with the Facility to review remedy design documents, with the focus on starting construction of the soil remedies in August 2014. The soil remedy construction occurred between September 2014 and April 2015. This work involved the excavation of impacted soils, construction of a Consolidation Area at the former cell room location, consolidation of soils and installation of a temporary cover over the Consolidation Area and installation of vegetated soil (and gravel) covers. EPA issued a construction complete determination for the CMI report documenting this work on February 17, 2016. EPA also worked through the review of pilot study reports and the development of design documents for two in situ groundwater treatment remedies and the sediment remedy between 2015 and 2016. We expect to complete the design phase for the groundwater remedies in 2016 and to proceed with full-scale implementation in 2017.

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Site Description

Interactive Map of Occidental Chemical Corporation, New Castle, Delaware

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The Occidental property consists of a former manufacturing area covering approximately 20 acres, several former waste lakes and landfills totaling approximately 13 acres, and marshlands totaling approximately 215 acres. The plant operated as a chlor-alkali plant from 1964 through 2005. The plant stopped chlorine production in November 2005, and stopped production of anhydrous potassium hydroxide in 2007. Decommissioning and demolition of most of the plant structures was completed in 2007 and 2008 to make the property suitable for industrial redevelopment.

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Contaminants at this Facility

The primary contaminants that are present in the soils, surface water, sediments, and groundwater are volatile organics such as benzene, chlorobenzene, vinyl chloride and polycyclic aromatic hydrocarbons (PAHs) ; and heavy metals such as mercury.

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Institutional and Engineering Controls at this Facility

    Institutional /Engineering Control Summary
    Restrictions or Controls that Address: Yes No
    Groundwater Use
    Residential Use
    Vapor Intrusion
    Capped Area(s)
    Other Engineering Controls
    Other Restrictions

    Institutional controls for the site , enforced under an Environmental Covenant (UECA) agreement are:

    • No Groundwater wells shall be installed or groundwater withdrawn from any well on property without DNREC approval.
    • Use of property restricted to non-residential use.
    • There shall be no drilling, digging, excavation without prior approval of DNREC.
    • The facility will comply with the site's Materials Management Plan including handling of subsurface material.

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    Land Reuse Information at this Facility

    Decommissioning and demolition of most of the plant structures was completed in 2007 and 2008 to make the property suitable for industrial redevelopment.

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    Site Responsibility at this Facility

    RCRA Corrective Action activities at this facility are being conducted under the direction of the EPA Region 3 with assistance from Delaware DNREC.

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