CHARLESTON, W.Va. (AP) — In two weeks, federal investigators will start carving up chemical tanks for evidence in a spill that tainted 300,000 West Virginians’ water supply.

The Chemical Safety Board plans to begin removing slices of three Freedom Industries tanks in Charleston on April 24, agency spokeswoman Hillary Cohen said. It will take 11 days to secure the chunks of metal using high-pressure water jets, according to Freedom bankruptcy documents. Then they will be shipped off for a six-month lab work contract.