The U.S. Interior Department announced Tuesday it will reexamine the Trump administration’s decision to lease drilling rights in the Arctic National Wildlife Refuge, according to APM.

The move is legally complicated by a congressional mandate and because Interior has already issued nine leases to drill on ANWR’s coastal plain.

Interior Secretary Deb Haaland declared in June that the Trump administration’s environmental study justifying the leasing decision was legally deficient. According to a notice in the Federal Register, her department will conduct a “supplemental” environmental impact study, followed by a decision that may impose new limitations on drilling.