Jan. 23, 2009
Vol. 39, No. 21

Contact: James Werner, Director, Division of Air and Waste Management, 302-395-2600; or Melinda Carl, Public Affairs, 302-739-9902

Final Plan of Remedial Action Approved for DuPont’s
Hay Road Sludge Drying “Iron Rich” Site in Wilmington
Order Also Directs Broader Analysis of Dredge Material 

Dover, Del. – The Department of Natural Resources and Environmental Control has approved a Final Plan of Remedial Action for DuPont’s 22.7-acre Hay Road Sludge Drying “Iron Rich” site located on Hay Road in the Cherry Island area of Wilmington. DNREC Secretary John A. Hughes directed the adoption of the plan in an Order last week dated Jan. 16, 2009.

The order also directs, as recommended by DNREC’s Site Investigation and Restoration Branch technical staff, future investigation of potential environmental impacts of the dredge material beneath the Iron Rich material at the sludge drying location and other sites along the Shellpot Creek and Delaware River.

The required remedy includes capping of the Iron Rich material, a byproduct of DuPont’s titanium dioxide manufacturing facility at 104 Hay Road, Edge Moor, and further monitoring and investigation of the dredge material to ensure the site is fully protective of human health and the environment. This remedy is based on all of the data for the Iron Rich material, the dredge material and the surrounding environment.

The Iron Rich material was stored at the property by DuPont between 1997 and 2001 when DuPont intended to market the Iron Rich material as a product.

The plan of remediation was prepared by DNREC’s Site Investigation and Restoration Branch pursuant to the Delaware Hazardous Substance Cleanup Act. The Department held a public workshop on the site in January 2005, and public hearings on the proposed plan March 2, 3 and 9, 2005.

Following passage of House Concurrent Resolution 22 by the Delaware General Assembly seeking an independent study of the property, DNREC retained Schnabel Engineering North LLC, which submitted its independent study in a Dec. 20, 2006 report.

The Schnabel report noted deficiencies in DuPont’s remedial investigation/risk assessment report for the site that they recommended be addressed by collection of additional data for the complete evaluation of the site and risk assessment.

The original public comment period was extended by DNREC to allow comments on the Schnabel study. Subsequent technical work and data analysis by DuPont during 2007 and 2008 resulted in a Dec. 8, 2008 addendum to remedial investigation/risk assessment submitted by DuPont, which was reviewed by Schnabel and DNREC. This report was conditionally approved by DNREC on Dec. 18, 2008.

On Jan. 14, 2009, DNREC’s Site Investigation and Restoration Branch (SIRB) provided a technical response memorandum reaffirming the remedial action in the proposed plan of remedial action.  The SIRB technical memo also indicated, however, that a separate area-wide groundwater monitoring program should be implemented to allow increased evaluation of the hydrogeology and chemistry of the underlying dredge material and groundwater to determine the potential impact to the surrounding environment, including Shellpot Creek.   The Department intends to undertake this recommended analysis of the underlying dredge material with involvement of interested parties.

The Order, Hearing Officer’s Report and attachments are available for review on the Division of Air & Waste Management's web site at: www.dnrec.delaware.gov/whs/awm/Pages/default.aspx .