Water sources may become contaminated with pesticides as a result of:

Runoff from treated areas is a significant pathway for pesticide contamination of water sources. When pesticides are applied to agricultural fields, lawns, or other landscapes, rainwater or irrigation can wash these chemicals off the surface and carry them into nearby rivers, lakes, and groundwater. This process is particularly concerning after heavy rainfall or rapid snowmelt, which increases the volume of water flowing over treated areas, thereby enhancing the potential for transfer of pesticides into water bodies.

Effective management practices, including buffer zones and proper application techniques, are crucial in mitigating this risk. Understanding this pathway is vital for regulatory enforcement and ensuring that pesticide applications do not adversely affect the environment and water quality.

While leaking storage containers, inadequate personal protective equipment, and high wind conditions are also important factors in the safe handling and application of pesticides, they do not directly relate to the contamination of water sources in the same manner as runoff.