Phases of Site Cleanup
While ownership has changed several times, Mallinckrodt, Hanlin and HoltraChem have each worked to advance the cleanup. Several of the actions which HoltraChem and Mallinckrodt have taken to control and clean up pollution at the plant are listed below:
- Installed riprap on the riverbank next to one of the plant landfills to prevent erosion and river contamination;
- Installed a groundwater collection system to capture a portion of contaminated groundwater discharging from the site for treatment;
- Instituted measures to prevent contaminated sediment from reaching the river, and
- Constructed a new wastewater treatment plant for the treatment of contaminated groundwater.
The Site cleanup requires:
- removal of landfills 1 and 2;
- updated caps on the remaining three landfills (3, 4, and 5);
- removal of contaminated soils and contaminated structures;
- treatment of contaminated groundwater and surface water;
- removal of contaminated onsite sediments and Penobscot River sediments near the site,
- studies to implement the order and to delineate contamination areas;
- transportation infrastructure upgrades to support removal of contamination from the site;
- comprehensive monitoring including air quality monitoring;
- restoration of onsite streams; and
- site security.
Implementation of studies and delineation will begin during the summer of 2014.