To limit the probability that an ignition source from an adjacent property will ignite vapour from the pump, which could lead to a fire or explosion, which could lead to harm to persons in the facility.
To limit the probability that vapour from the pump will accumulate on the adjacent property, which could lead to ignition of the vapour from an ignition source on the adjacent property, which could lead to a fire or explosion, which could lead to harm to persons in adjacent buildings or facilities.