Twelve companies have agreed to pay $3.9 million towards the cleanup of a San Gabriel Valley Superfund site, the U.S. Environmental Protection Agency announced Thursday.

The site, a 190-acre landfill in Monterey Park run by Operating Industries Inc., accepted hazardous liquid and solid waste from industrial companies from 1948 until it closed in 1984. In 1986, the EPA placed it on its national priority Superfund list of most polluted sites.

Since then, the EPA has secured more than $600 million from various industrial companies that had disposed waste at the site, using the “polluter pays” provision in federal toxic waste law.

Thursday’s announcement adds 12 more companies to the list, including Ameron International of Pasadena, B&C Plating Co. of Los Angeles, International Extrusion Corp. of Alhambra, Jaybee Manufacturing Corp. of Los Angeles, Princess Cruises of Valencia, and Halliburton Energy Services Inc. of Houston, Texas.