Shell Oil Co. has agreed to provide $21 million in cash and land for the cleanup at the Rocky Mountain Arsenal, where the company made pesticides and other chemicals from 1952 until 1982, Legal Newsline reported Thursday.

"The settlement eliminates the need for the state to spend millions of additional dollars and more years litigating a case for an uncertain result and will allow for the protection of parcels of land around the arsenal before they are forever lost to development," Attorney General John Suthers said.

The U.S. Army, which has agreed to pay the state $17.4 million, manufactured chemical weapons at the 27-square-mile site northeast of Denver starting in 1942.

The proposed settlement still must be approved by a federal judge. If approved, the settlement would end a lawsuit filed in 1983 over environmental damage at the site, Legal Newsline said.

The Rocky Mountain Arsenal was designated a federal Superfund site in 1987 by the U.S. Environmental Protection Agency.