Sentinel Data Center, East Whiteland Township, Pennsylvania

Earth-moving has begun on the Sentinel Green Fig data center, a campus of about 1.5 million square feet that Sentinel Data Centers and Green Fig LLC are building on the former Foote Mineral Superfund site at 13 South Bacton Hill Road in East Whiteland Township, near Exton, in Chester County, Pennsylvania. The township halted the early work in July 2026 over its review of soil and health safety plans, then let it resume on July 29 after issuing an erosion and sedimentation permit with conditions on soil monitoring, dust control and protection of the Superfund remedy.

The 2024 plan, which won preliminary approval on June 12, 2024 and final approval with conditions on August 14, 2024, shows two two-story buildings with basements and a footprint of 1,544,700 square feet, next to PECO's Planebrook substation near Swedesford Road. The Board of Supervisors says it was legally obliged to sign the plan in March 2026 once staff found the conditions met, and it was recorded with the county on March 31, 2026. That plan would use about 3 million gallons of water a day for cooling. The land was zoned for a data center of up to 1,860,000 square feet, and the project dates to 2022, when Fifteenfortyseven Critical Systems Realty and Green Fig Land Company began planning it; Sentinel joined in 2024.

Foote Mineral processed ores there from about 1941 until 1991, leaving lithium, boron, arsenic, hexavalent chromium and low-level radiation, and the site remains on the EPA's National Priorities List. The EPA told the developers any reuse must not interfere with the cleanup remedy and asked for a health and safety plan and a soil management plan before work began; it says the development is limited to parcels next to the capped quarry and that there have been no violations of the environmental covenant. Malvern resident Kelly Donia said, “No one seems to be concerned, but I mean, we live right here, we work right here,” adding that there are children and a daycare nearby.

Faced with opposition, Sentinel filed a smaller amended plan in late 2025, and in April 2026 CEO Josh Rabina warned that if approval was delayed or further appeals were filed, “we will simply have no choice but to continue building the current plan.” The developer then withdrew the amended plan and said it would build the 2024 plan it already had permission for. In July it returned with a “field change” to swap cooling towers for rooftop air-chilled units, which it said would cut water use to effectively none, and a smaller total footprint of 536,000 square feet; the supervisors voted 2-1 to table the request. “This isn’t moving a pipe from five feet away to have some mud moved on top of it. This is a half-a-million-square-foot change,” said Tony Gianino. “This is a completely new project.” “In either event, Sentinel is proceeding with development,” said Lou Colagreco, the developers' attorney.

A Chester County judge dismissed appeals challenging earlier approvals. The developers still need construction permits for work such as pouring footings and foundations, which the township says it must process. The East Whiteland Township Board of Supervisors decides the cooling “field change,” which was still pending as of August 19, 2026. Opposition to the project also drove a petition, signed by at least 500 residents, that puts a question on the November 3 ballot asking whether to expand the board from three members to five. That same week Gov. Josh Shapiro signed an executive order requiring local approval for data center projects to receive state permits.