EPA Cleanup Plan
After comprehensive environmental investigations and public input, EPA released its cleanup plan for soil and groundwater at the Quanta site in September 2011. Major components of the cleanup plan include:
- Soil solidification: In-place solidification of soil contaminants, a process that involves mixing cement into contaminated soil to permanently lock up arsenic, coal tar, and waste oils so these contaminants cannot move.
- Deep collection well installation: Installation of a deep well recovery system to capture "non-aqueous phase liquid" (NAPL) - mostly coal tar and used oil - to alleviate any future migration of that material.
- Groundwater barrier installation: Installation of a "subaqueous reactive barrier" to prevent contaminants in groundwater from reaching the Hudson River. A subaqueous reactive barrier is a permeable mat with a layer of reactive material in it. It will be placed on top of underwater sediments where contaminated groundwater will flow through it. As the groundwater moves through the mat, contaminants are trapped in it, and treated groundwater flows out the other side. The groundwater barrier will be installed later as part of the cleanup for the offshore portion of the site, known as Operable Unit 2, or OU2.
- High-concentration arsenic area (HCAA): Design of the treatment for the HCAA has not yet been finalized. A separate schedule is currently being developed for this area.
Major Components of the EPA-Approved Remedy