In a comment on this answer, user V2Blast suggests that you could circumnavigate* a creature, then push them into a hazard. This would enable moving a grappled creature into a hazard without first moving through the hazard yourself.
The basic combat rules explain that, if you are grappling another creature:
When you move, you can drag or carry the grappled creature with you, but your speed is halved, unless the creature is two or more sizes smaller than you.
Drag is very specific, and implies that the target follows you. Carry, however, imposes no such restraint. Can 'carrying' include movement in which the grapple-target is adjacent to you, but is 'in front' of you relative to the direction of movement?
Two simple diagrams for visual thinkers
Tar = Target; Gra = Grappler; --> = movement direction ## I know you can do this: Tar|Gra|-->| ## I want to know if this is possible: Gra|Tar|-->|
* The need for circumnavigation is brought about by the fact that moving a grappled creature can only occur 'when you move' according to RAW, which implies that moving a creature relative to oneself is impossible. This is outside of the scope of this question, please answer that question there and this one here.