For firefighting purposes, you absolutely can use an OUTBACK Plunge Pool instead of a traditional tank. In fact, this is often a better solution as the filtration system ensures the correct water volume is maintained, so you can be assured the volume of the static water source is always correct during an audit.
Can the pool shape be modified?
Unfortunately no. For this type of pool, the round shape is the only option. Straight-edged pools such as square or rectangle shapes will bulge on