General Electric will start sampling the floodplain in a section of the Housatonic River in Massachusetts later this month, in preparation for a toxic waste clean up.
The U.S. Environmental Protection Agency said the start of the sampling is "subject to weather conditions and high river flows."
GE contaminated the river with PCBs from the 1930s through the 1970s at its now closed electrical transformer plant.
It will collect samples in a stretch from the confluence of the east and west branches of the river in Pittsfield down to the Lenox line.
The goal is to figure out the volume of floodplain soil that will be dug up -- and how much of the contaminated material has PCB concentrations low enough to be disposed of in a yet-to-be-built facility in Lee. The sampling analysis will also determine how much has higher average concentrations of the toxin and will be trucked out of state.
GE's plan for sampling in the riverbank and in the river bottom still needs EPA approval.
Dean Tagliaferro, of the EPA, said nearly 11,000 samples will be collected there.
"It could be a full year to collect all these samples. So, it's a really major sampling event," he said.
A small percentage of the samples, about 5%, will be analyzed separately by GE and the EPA.
Although the EPA's clean up permit went into effect March 1, two environmental groups are fighting the plan to build the disposal site in the Berkshires. They said they will file an appeal in federal court.
Besides sampling for the future cleanup, GE and the EPA plan to sample for PCBs this summer in the first two miles of the river, which was cleaned up previously. The first half mile stretch south of the plant was remediated 20 years ago.