Humboldt Waterkeeper addresses water pollution on a case-by-case basis, and provides information to encourage residents to take action to address the problem of toxics in our environment. Historic industrial activity continues to impact the Bay and adjacent waterways as well as human health and the area’s economy. Dioxins, heavy metals, petroleum products, and other contaminants persist in areas where they were used in the past, and continue to enter Humboldt Bay and coastal waters through stormwater and groundwater discharges. Humboldt Waterkeeper works to stop this ongoing problem by seeking cleanup of these sites. A major focus of Humboldt Waterkeeper’s Toxics 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 Waterkeeper’s Toxic Initiative, this ongoing threat to Humboldt Bay was identified, and has been the subject of clean up activities to eliminate this source of dioxin.In 2006, Humboldt Waterkeeper petitioned the State Water Resources Control Board to add Humboldt Bay to California’s Threatened and Impaired Waters list under Section 303(d) of the Clean Water Act. As a result, Humboldt Bay was listed for dioxins in 2007. Humboldt Bay was listed as Impaired by PCBs under Section 303(d) of the Clean Water Act in 2002, based on levels of PCBs found in fish tissue. PCBs have been demonstrated to cause a variety of serious health effects, including cancer and serious effects on the immune system, reproductive system, nervous system, and endocrine system. Click HERE for more info on PCBs and their health effects. In 2012, a statewide survey of coastal fish found the highest mercury levels in Humboldt Bay leopard shark. In 2016, the California Environmental Protection Agency funded our Humboldt Bay Mercury Assessment to study mercury levels in fish and to identify communities most at risk of exposure. Phase I of this study was completed in 2018, and Phase II was funded in 2019. 
On the August edition of Baykeeper’s EcoNews Report, Jen Kalt interviews Ted Hernandez, Michelle Vassel, and Tim Nelson, of the Wiyot Tribe about the return of Indian Island to the tribe, the cleanup of the contaminated former boatyard at Tuluwat Village, and the recent revival of the tribe’s World Renewal ceremonies that were interrupted in 1860 by brutal massacres. 
In 2000, the U.S. Environmental Protection Agency adopted the California Toxics Rule, establishing water quality standards for pollutants toxic to the state’s rivers, lakes, bays, estuaries, and wildlife.
How we will prepare for rising sea levels is just beginning to take shape here in the Humboldt Bay region. Humboldt Baykeeper assessed sea level rise vulnerability for contaminated sites near Humboldt Bay. More than 300 contaminated sites are within 10 meters of current sea level, including more than 40 that are below 2 meters – the amount sea level is currently projected to rise by the year 2100.
