Final Plan of Remedial Action for Chestnut Run Plaza Dupont Operable Unit 1 (OU-1) Site (DE-1778)

Division of Waste and Hazardous Substances

Published: Oct. 9, 2022

The Department has adopted a plan regarding the clean-up of the Chestnut Run Plaza DuPont Operable Unit 1 (OU-1) Site located in Wilmington. The Site was formerly used for research and development and is being redeveloped into a similar operation.

The Site requires a Remedial Action Work Plan for the onsite remedial actions; Hotspot Soil Removal of the soil under the slab along with post-excavation sampling; Environmental Management During Construction- Develop and implement a Contamination Material Management Plan (CMMP); Vapor Mitigation System; Institutional Controls- placement of an environmental covenant limiting site use to commercial use, groundwater withdrawal and compliance with the CMMP, Long-Term Stewardship (LTS) Plan and prohibiting building renovations or demolition without prior DNREC notification; LTS Plan to monitor air to ensure that vapor migration system is effective and Remedial Action Completion Report.

DNREC issued a public notice of the Proposed Plan for the Chestnut Run Plaza DuPont OU-1 Site on September 11, 2022. In addition, DNREC held a public workshop on the Proposed Plan on September 26, 2022 from 4 pm to 6 pm on the Site. No members of the public attended. There were no comments or questions from the public regarding the Proposed Plan. Details of the Final Plan are available online at:

For additional information, please contact Rick Galloway, Project Manager at (302) 395-2600 or via email at