On March 2, 2023, the Region issued a unilateral administrative order under CERCLA Section 106, directing the Respondent to perform the remedial design for the interim remedy selected in September 2021 for the upper nine miles of the Lower Passaic River, part of the Diamond Alkali Superfund Site. The Lower Passaic River flows through Essex, Hudson, Bergen and Passaic Counties, New Jersey. EPA estimates that the remedial design work required by the order will cost $115 million.