EPA has announced plans to place additional limitations on the use of three organophosphate pesticides — chlorpyrifos, diazinon and malathion — to protect endangered and threatened salmon and steelhead in California, Idaho, Oregon and Washington.
Anticipated changes to product labels include the addition of pesticide buffer zones; application limitations based on wind speed, soil moisture [...]

Numerous studies over the past four decades have established that pesticides, which are typically applied at the land surface, can move downward through the unsaturated zone to reach the water table at detectable concentrations. The downward movement of pesticide degradation products, can also contribute to the contamination of ground water.
Once in ground water, pesticides and [...]