Humboldt Baykeeper is addressing polluted sites and substances on a case-by-case basis, and providing information to Humboldt Bay residents, helping them take action to address the problem of toxics in our environment.  Humboldt Baykeeper’s Toxics Initiative identifies and addresses the many contaminated sites in the Humboldt Bay region, and their associated threats.  Historic industrial activity continues to impact the Bay and has long-term implications for the health of local residents and the area’s economy. Toxics, such as dioxin, heavy metals and petroleum products persist in areas where they were used in the past, and continue to enter Humboldt Bay through storm water and ground water discharges.  Humboldt Baykeeper works to stop this ongoing problem by seeking cleanup of these sites.

One focus of Humboldt Baykeeper’s Toxic Initiative is the past use of wood preservatives at dozens of lumber mills that once lined the shores of the Bay and its tributaries. The mills used the chemical pentachlorophenol (also known as "penta") which led to the release of contaminants such as dioxins and furans. Accidental spills and illegal dumping of these chemicals resulted in soil and water contamination. For example, the Former Simpson Plywood Mill, and an adjacent drainage swale that discharges directly into Humboldt Bay, was heavily contaminated by dioxins and furans. Through Humboldt Baykeeper’s Toxic Initiative this ongoing threat to Humboldt Bay was identified, and is currently undergoing clean up activities to eliminate this source of dioxin.

In 2006 Humboldt Baykeeper petitioned the State Water Resources Control Board to have Humboldt Bay included on California’s Clean Water Act § 303(d) Impaired Waters list.  As  result of this successful petition, Humboldt Bay has been listed, and numerous stakeholder groups have come together in the Humboldt Bay Dioxin Working Group to determine a holistic approach to moving forward and eliminating the sources of dioxin into our Bay.