[2] Montrose's former main plant in Harbor Gateway South area of Los Angeles[3] near Torrance, California has been designated as a Superfund site by the United States Environmental Protection Agency.
[6] In addition, the company dumped hundreds of thousands of barrels containing waste laced with DDT at a deep sea site located between the California coast and Santa Catalina Island during the same time period.
In 2011 and 2013, Professor David Valentine and a research team at UC Santa Barbara discovered barrels of DDT leaking on the ocean floor which extended well beyond the spills at Montrose's Superfund site.
Other bottom-feeding fish, including kelp bass, rockfish, queenfish, black croaker, sheepshead, surfperches and sculpin, are also highly contaminated.
In 1990, the United States and California filed lawsuits against Montrose Chemical and nine other facilities near the Palos Verdes peninsula, citing damages to the nearby marine environment.