Sacramento River pesticide spill
The Sacramento River pesticide spill, also known as the Cantara spill, occurred on July 14, 1991, when a Southern Pacific train derailed near Dunsmuir, California, releasing 19,000 gallons of the pesticide metam sodium into the river. This incident resulted in the deaths of over one million fish, including more than 300,000 trout, and had devastating effects on local wildlife and plant life, leading to significant ecological disruption. The spill contaminated a critical habitat for various species and caused extensive damage to the river's vegetation, which in turn affected animals that relied on these plants for sustenance and shelter. Although the chemical's presence in the water diminished within weeks, the recovery of the ecosystem was slow and required ongoing intervention, including the planting of new trees by the US Department of Fish and Game. By the mid-1990s, some species began to show signs of recovery, but others, like clams and certain amphibians, continued to struggle. The event also had economic repercussions for the Dunsmuir community, as outdoor recreational activities were halted for an extended period. In a more recent event, in August 2021, another train derailed at the same location, but this time, no pollutants were released into the river. The lingering effects of the 1991 spill highlight the complexities of environmental recovery and the importance of ongoing monitoring and restoration efforts.
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Sacramento River pesticide spill
THE EVENT: Train derailment near Dunsmuir, California, that spilled thousands of gallons of the pesticide metam sodium into the Sacramento River
DATE: July 14, 1991
The Sacramento River pesticide spill resulted in the deaths of more than one million fish and thousands of birds and other animals that shared the river habitat. Although the chemical contamination was short-lived, the ecological consequences were long-lasting.
On the night of July 14, 1991, a Southern Pacific train derailed at the Cantara Loop north of Dunsmuir, California, causing a chemical tank car to rupture and spill 19,000 gallons of the metam sodium into the upper Sacramento River. This event, known as the Sacramento River spill or the Cantara spill, was the largest inland ecological disaster that had taken place in California up to that date. As the metam sodium rapidly mixed with the river’s water, it released highly toxic compounds, virtually sterilizing what had been one of the premier trout streams in California. The green plume eventually flowed 58 kilometers (36 miles) downstream into California’s largest reservoir, Lake Shasta, where a string of air pipes placed at the bottom of the lake aerated the chemical. The project accelerated the breakdown of the metam sodium, reducing toxic components to undetectable levels by July 29, 1991.
Studies were launched to identify and quantify the spill’s damage to natural resources. Exposure to the pesticide had killed all the aquatic life in the Sacramento River between the Cantara Loop and Lake Shasta. More than one million fish died, including more than 300,000 trout. Millions of insects, snails, and clams perished, along with thousands of crayfish and salamanders. Hundreds of thousands of trees, particularly willows, alders, and cottonwoods, eventually died as a result of the of the water, and many more were severely injured. The vegetative damage caused a corresponding dramatic loss of many wildlife species that depended on the river’s vegetation for food and shelter. Birds, bats, otters, and mink either starved or were forced to relocate to other areas because their food sources were no longer available. In addition to the devastating effects on wildlife and plant life, the spill produced many reported negative effects on human health. It also halted recreational activities for miles along the river, resulting in substantial economic losses for the residents of the Dunsmuir area.
Although virtually no trace of the metam sodium remained in the river about one month after the spill, it became clear that full recovery remained years away. In 1992 the US Department of Fish and Game planted more than three thousand trees to accelerate the recovery of severely injured vegetation along the river. Some plants, such as elephant ears and torrent sedge, recovered after two growing seasons. During 1994, the trout reached about one-half of what it was prior to the spill, and trout angling was again allowed on the river. However, strict regulations were established that would allow protection for the recovering wild trout fishery.
By late 1995, ospreys, dippers, sandpipers, and mergansers were all making good progress toward recovery. By 1996, many aquatic and insect populations were nearing numbers that existed prior to the spill; some species, however, particularly clams, snails, crayfish, and salamanders, were struggling to make a comeback. To accelerate recovery, which continued into the twenty-first century, state and federal trustee agencies spent several million dollars to fund specific projects, including research, recovery monitoring, acquisition and restoration, resource protection, and public education.
On August 2021, roughly one month after the thirtieth anniversary of the spill, another train derailed at the Cantara Loop. Eighteen train cars went off the rails, with numerous cars entering the river. However, this time, the tanker cars that fell into the river were empty. Shortly after the incident, the California Department of Fish and Wildlife confirmed that no pollutants had spilled into the river.
Bibliography
Elmer-Dewitt, Philip. “Death of a River: An Ecological Catastrophe in California Points to the Need for New Rules on the Transport of Toxic Compounds.” Time, July 29, 1991, 24.
Friis, Robert H. “Pesticides and Other Organic Chemicals.” In Essentials of Environmental Health. Sudbury, Mass.: Jones and Bartlett, 2007.
Hill, Marquita K. “Water Pollution.” In Understanding Environmental Pollution. 3d ed. New York: Cambridge University Press, 2010. Sabalow, Ryan. "Train Derails in Northern California Near Site of Chemical Spill Disaster 30 Years Ago." The Sacramento Bee, 30 Aug. 2021, www.sacbee.com/news/california/article253817608.html?fbclid=IwAR2T7CV‗VbqumgW3kzsi9hYfOsVrUQ0NPB5NhwcLncEScUILe0Q4qZI2WQA&‗ga=2.237712706.393906060.1721773836-476140362.1721773836. Accessed 23 July 2024.