Verdantas is proud to partner with the State of Delaware on the transformative redevelopment of the historic Custom House in downtown Wilmington. Originally constructed in 1855, the Custom House is the city’s second oldest building and served as Delaware’s first federal building, post office, and U.S. Courthouse. This $77 million initiative will restore the 15,000-square-foot landmark and introduce a 51,650-square-foot wrap-around addition to support ceremonial functions and non-jury legal proceedings.

Groundbreaking took place in December 2023, with completion anticipated by July 2026. The project exemplifies Verdantas’ multidisciplinary collaboration, with contributions from our Environmental Assessment & Remediation (EAR), Civil, and Geotechnical teams, alongside dedicated field staff.

Early geotechnical investigations, including standard penetration test (SPT) drilling, provided critical insights into subsurface conditions, enabling our civil engineers to proactively address design challenges and streamline utility planning, stormwater management, and land development approvals. In parallel, our EAR team conducted a Brownfield Investigation following the site’s 2018 certification as a Delaware Brownfield Site. This assessment identified a vapor intrusion risk, prompting the design and DNREC-approved installation of a vapor mitigation system beneath both the existing structure and the new addition.

The project’s success is rooted in Verdantas’ integrated approach. Our EAR and Geotechnical teams have cross-trained field staff to perform both environmental and geotechnical tasks—ranging from health and safety oversight to soil compaction and concrete testing—resulting in cost savings, enhanced team versatility, and streamlined communication.

This redevelopment not only preserves a vital piece of Delaware’s history but also showcases Verdantas’ commitment to sustainable, collaborative solutions. Special recognition goes to Nicholas Piane and Bob Smagala (EAR), James Taylor (Civil), Charlie Mallon (Geotech), and our field teams for their continued dedication.