Shouldn't rather the entity importing the plastic take responsibility for disposing of it? As you say it might even create jobs, but I'd say it should befall the consumer to take care of the waste they produce in any case, instead of simply shipping it away.
Easy to enforce? I dunno - why not require country of origin for packaging?
But assuming that won't happen - sounds like an opportunity for US jobs.
Plastic might make decent bricks for building.