Both through natural run-off to rivers and streams and via stormwater drains, a number of cities within and up stream of the Delta release hundreds of thousands of gallons of water containing contaminants and toxic chemicals each day. According to the Center for Biological Diversity, both the smelt and the plankton on which it feeds are suffering direct mortality or impairment from the presence of toxic substances in the water. Pyrethroids, among the most widely used home pesticides, are winding up in the Delta at toxic levels, and endangering the food supply of fish and other aquatic animals, according to a new study by researchers at the University of California, Berkeley. Pyrethroid insecticides, commonly used in California to kill ants and other pests around the home have been widely found in street run-off and in the outflow from sewage treatment plants in the Sacramento area. The insecticide is being found in two urban creeks, the San Joaquin River and a 20-mile stretch of the American River, traditionally considered to be one of the most pristine rivers in the region. Pyrethroids have been around for decades, but their use skyrocketed after 2004 when other home-use pesticides were banned. The main sources appear to be readily available insecticides applied around the home by homeowners or professional pest control operators to control pesky ants.
Storm Runoff and Sewage Treatment Outflow Contaminated With Household Pesticides Article in Science Daily (Feb. 3, 2010)
Pollution’s high price tag...Stockton settles pollution lawsuit for $4 million Article in the Chico News & Review (Aug. 6, 2009)
Urban pesticides found to be major Delta stressor...Sacramento again major polluter Editorial in Stockton Record (July 16, 2009)
Sacramento area is Delta's top pesticide source, study finds Article in Sacramento Bee (July 14, 2009)
Environmentalists, Water Users Blame Delta Cities and San Joaquin County for Delta's Fragile State
The Coalition for a Sustainable Delta and the California Sportfishing Protection Alliance say they intend to sue several Bay-Delta cities and San Joaquin County for pollution coming from stormwater runoff and sewage. The highly toxic runoff and pollution are believed to play a significant role in the estuary's decline and impacts to key threatened and endangered species.
Press Release: Delta Coalition Initiates Legal Action on Illegal Pollution Discharges (July 1, 2008)
Notice of Intent to Sue for Violations of the Clean Water Act and Endangered Species Act