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Pesticides in groundwater can eventually contaminate well water.

Detailed Description

Chemicals can take a long time to appear in groundwater

The effects of past and present land-use practices may take decades to become apparent in groundwater. When weighing management decisions for protection of groundwater quality, it is important to consider the time lag between application of pesticides and fertilizers to the land and arrival of the chemicals at a well. This time lag generally decreases with increasing aquifer permeability and with decreasing depth to water.