Final Plan of Remedial Action for Fort Dupont Operable Unit 4 [OU-4] Grassdale (DE-1618)

Division of Waste and Hazardous Substances

Published: July 11, 2021

The Department has adopted a plan regarding the clean-up of the Fort DuPont Operable Unit 4 (OU-4) Grassdale (DE-1618) Site located in Delaware City. OU-4 is the fourth of several areas within the over 300-acre Fort DuPont Facility intended to be investigated and redeveloped as part of a revitalization effort. The portion of the Fort Dupont Site identified as OU-4 was formally known as the ‘Grass Dale’ Center, or Grassdale, and was a former equestrian rehabilitation center. The State of Delaware acquired OU-4 in September 1994 and used the Site as a park and recreational activities. Fort DuPont Facility OU-4 Grassdale will be subject to the following key remedial actions: the recording of an Environmental Covenant restricting groundwater withdrawal; and, the submittal of a Remedial Action Completion Report.

DNREC issued a public notice of the Proposed Plan for the Fort DuPont OU-4 Grassdale Site on May 30, 2021 and extended the public comment period notice until July 6, 2021, due to website upload error. 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 Morgan McGee-Solomon, Project Manager at (302) 395-2600 or via email at