The Pharmacia Corp. and Bayer CropScience Inc. have paid state and federal agencies $4.25 million for damaging natural resources at the Industri-plex Superfund site in Woburn.

Contaminants from this site significantly impacted resources in the Aberjona River and the surrounding watershed, according to the state Department of Environmental Protection.

From the 1850s to the 1960s, companies manufactured products at the Industri-plex site including sulfuric acid, arsenic insecticides, organic chemicals, munitions and glue. Hazardous substances disposed there degraded the Aberjona River, as well as wetlands and the Mystic Lakes downstream. These habitats are used by a variety of wildlife, including fish, turtles, amphibians and migratory birds, such as great blue herons, black ducks and kingfishers.

"With this settlement, we can fund a range of projects designed to restore the natural resources for all to enjoy," state Energy and Environmental Affairs Secretary Rick Sullivan said in a statement. "I encourage local residents and organizations to become engaged in the public process that will take place as we solicit, take comment on, and choose these projects in the months ahead."

When toxic substances enter the environment and injure natural resources, federal and state environmental officials act as trustees for these resources.