Study finds home-use pesticides major source of pollution in Sacramento-San Joaquin Delta

Urban Sacramento is the leading source of pesticide contamination disrupting the Delta aquatic environment, according to new research on pollution in the estuary.

The study, led by UC Berkeley toxicologist Donald Weston, found enough pyrethroid pesticides in the American River to kill tiny shrimp – among the first links in the aquatic food chain. Those pesticides likely reached the river from urban storm drains, which collect runoff from the Sacramento area's 1.4 million residents.

For five years, biologists have hunted for the cause of a collapse in the Sacramento-San Joaquin Delta ecosystem, a water supply for 23 million Californians. Nine fish species are declining, from tiny Delta smelt to giant green sturgeon. Weston's research supports the theory that no single villain is to blame.

Read the full story at