What is a crucial step that enhances fire ground safety regarding water supply?

Staging key pumpers on hydrants is a crucial step in enhancing fire ground safety regarding water supply because it ensures immediate access to a reliable water source during firefighting operations. When pumpers are strategically placed at hydrants, they can quickly supply water to firefighting efforts, allowing for a more efficient and effective response to the fire. This setup minimizes the time lost in establishing a water supply, which is critical in life-saving situations and in controlling the fire before it extends further.

Additionally, having pumpers on scene ready to access hydrants allows for redundancy and a faster replenishment of water supply, which is vital in large-scale incidents or when multiple lines are in use. This method also facilitates better coordination among units as they can communicate effectively and ensure there is enough water available when needed.

In contrast, the other options may not provide the same level of safety or efficiency. For example, relying solely on portable tanks can limit the volume of water available compared to a hydrant supply, while limiting the number of units or manpower may compromise response effectiveness and resource availability in emergency situations.