Commerce Street Brownfield

Landmark performed the complete civil engineering design of this major new import-export business location in South Wilmington, Delaware. The property is being developed to support a shipping business at the Port of Wilmington, and includes the proposed construction of 10,200 square feet of new construction and the rehabilitation of a 7,600 square foot building.

The Landmark team provided integrated engineering and environmental consulting services to obtain an Nationwide Permit (NWP38) from the USACE for filling seven acres of contaminated wetlands – gaining substantial buildable land value and valuable waterfront industrial access. This site was combined with an adjacent parcel of land requiring remediation, creating a much more valuable, combined, single-project-site for an import-export operation.

This 29.4-acre site is a heavily contaminated location with significant wetland areas produced as a result of past filling. Landmark obtained all necessary approvals from the City of Wilmington and permission to fill contaminated wetlands using USACE NWP 38, specifically designed for contaminated sites, and a Subaqueous Lands permit from DNREC.

Landmark performed a flood analysis of the lower tidal Christina River. A difficult and challenging portion of the project focused on the collection of surveyed cross-sections to perform the modeling. Landmark’s surveyors utilized GPS location by boat with a fixed reference to aid in providing a stabilized position located from the shore, as the corresponding depths were recorded. All data was collected in State Plane Coordinates. The resulting cross sections were then utilized in a hydraulic modeling program to evaluate and map a resultant floodplain for the project area.