Which statement regarding pre-incident planning is not true?

The statement that is considered not true regarding pre-incident planning is that a site visit may not be necessary if previous plans exist. This is inaccurate because pre-incident planning requires current and comprehensive information about a site, and relying solely on previous plans without verifying the current conditions can lead to gaps in knowledge. Conditions at a site may have changed since the last plan was developed, including alterations to structures, changes in operations, or new hazards that may not have been accounted for in earlier documents. Therefore, conducting a site visit is crucial for ensuring that the information is accurate and up to date, which supports effective emergency response.

In the context of the other statements, it is indeed essential for pre-incident plans to be regularly updated to reflect any changes, and these plans should consider unique site conditions to prepare responders adequately. The importance of site visits ensures that planners are equipped with the most relevant data, enabling them to address potential hazards effectively.