When performing decontamination, which category requires the use of a motorized flush?

The correct choice indicates that a motorized flush is required for equipment that has potentially been exposed to high-risk waters within the last 30 days. This is crucial for preventing the introduction and spread of invasive aquatic species, which can thrive in waters that are already affected by these organisms. High-risk waters are defined by their known presence of invasive species or outbreaks, making thorough decontamination essential to protect new environments from contamination.

Utilizing a motorized flush in this scenario ensures a more effective cleaning process. It allows for the removal of any attached organisms or spores that may otherwise survive manual cleaning methods, which can be insufficient against the resilience of many invasive species.

In contrast, the other categories do not warrant the same level of rigorous decontamination. Nonmotorized equipment may have different cleaning requirements, and freshwater does not inherently necessitate a motorized flush unless it is classified as high-risk. Similarly, the process is not generalized to all types of water bodies without considering the specific risk associated with each. Thus, the focus on high-risk water exposure underscores the importance of targeted measures in combatting invasive species through proper decontamination practices.