Looking FORWARD 

to the future

Moving Beyond HoltraChem

A methodical cleanup effort at the site of the former Holtrachem chlor-alkali manufacturing plant in Orrington, Maine continues to progress towards completion. Mallinckrodt US LLC (Mallinckrodt), the successor to one of the former owners of the site, has sole responsibility for remediating and restoring the site.


Remediation of the former HoltraChem plant site is focused on the 60 acres of the 235 acre site where the manufacturing operations occurred when the plant was in operation. Remediation activities to date have included site investigation, monitoring, demolition activities, excavation of contaminated soil, construction of a groundwater treatment plant, replacements of caps on Landfills 3, 4, and 5, and monitoring the site daily. A team of engineering firms with extensive experience in environmental remediation projects in Maine is working closely with Mallinckrodt US LLC and the Maine DEP to complete the project.


Site excavation work began in earnest in 2015 and the majority of the remedial areas have now been remediated and restored. During the course of the project, remediation and restoration of the areas known as Landfill Ridge, Landfill 2, Landfills 3, 4, and 5, Southerly Stream, Southern Cove and the Scrap Metal Yard have been completed. The remediation and restoration of the Landfill 1 Area  has also been completed. While initial restoration of the Northern Ditch has been completed, a portion of this area was used for staging of Landfill 1 work and final restoration was completed in 2019. Finally, the first phase of remedial work in the area where the former manufacturing operations took place, referred to as the Plant Area, has been completed and the Phase 2 design has been approved by the Maine DEP in early September. Phase 2 began in the fall of 2019.

Settlement Reached in Penobscot River Mercury Contamination Litigation