Surface waters in the Salinas and Santa Maria regions of California are contaminated with imidacloprid

Surface water monitoring for pesticides in agricultural areas of California is one of the California Department of Pesticide Regulation’s (CDPR’s) key environmental monitoring activities. The Salinas, Santa Maria and Imperial valleys have previously been designated as high priority areas for long-term surface water monitoring due to high pesticide use. This 2013 study is a continuation of the agricultural monitoring project. Grab samples were collected monthly from March to October in 5 regions:• Salinas - 16 Sites in Monterey County• Santa Maria - 5 sites in Santa Barbara and San Luis Obispo counties • Imperial - 9 sites in Imperial County• Palo Verde - 5 sites in Imperial and Riverside counties • Central Valley - 15 sites in San Joaquin and Merced counties. Pesticides with over 30% detections by regions:• Salinas - imidacloprid, befenthrin, λ-cyhalothrin, permethrin, methomyl, Methoxyfenozide, bensulide, oxyfluorfen • Santa Maria - imidacloprid, methoxyfenozide, bensulide, oxyfluorfen • Imperial – chlorpyrifos, dimethoate, malathion, befenthrin, λ-cyhalothrin, cypermethrin, pendimethalin, trifluralin • Palo Verde – pendimethalin.

Source: Deng X et al. Surface Water Monitoring for Pesticides in Agricultural Areas of California, 2013.
Surface Water Protection Program, Department of Pesticide Regulation, California Environmental Protection Agency (attached)