In the surface water protection program, how is a hydrologically isolated site defined?

The definition of a hydrologically isolated site in the context of the surface water protection program focuses on the treatment area's ability to prevent pesticide runoff from entering surface water systems. This means that any treatment area categorized as hydrologically isolated effectively ensures that no pesticides applied in that area can migrate into nearby surface water sources, including irrigation canals or drainage ditches.

This definition is important because it establishes criteria for how pesticide applications should be conducted in relation to bodies of water, to minimize environmental impacts and protect aquatic ecosystems. Ensuring that a treatment area does not produce runoff that can reach surface waters is key to maintaining compliance with regulations aimed at safeguarding water quality.

The other definitions provided do not correctly align with the established criteria for hydrologically isolated sites. For instance, local definitions that vary by county or contexts involving impermeable soil don’t provide a universal standard applicable across different regions. Additionally, defining a site as surrounded by surface water does not address the potential for runoff, which is the core concern of these regulations.