Ohio Attorney General Mike DeWine sued agricultural giant Monsanto on Monday, alleging the company concealed dangers posed by a toxic chemical compound it manufactured for nearly a half century.

In the suit, filed in the Hamilton County Common Pleas Court in Cincinnati, prosecutors argued that the company should pay for the clean-up of what it says are dozens of rivers, lakes and other water bodies contaminated with polychlorinated biphenyls, or PCBs.

“Monsanto should be held responsible for the damage it caused,” DeWine said in a statement.

Scott Partridge, Monsanto’s vice president of global strategy, gave a statement to NBC News saying: “Monsanto voluntarily stopped producing PCBs more than 40 years ago. Monsanto sold PCBs to many industrial and manufacturing customers, as well as the U.S. government, which put them to various uses and disposed of them in different ways. We are still reviewing this lawsuit, and we will defend ourselves aggressively.”