There was this Fun Run in the Philippines in 2013 that was supposedly for an environmental cause.
After the event, pictures were uploaded showing how much paper cups were thrown onto the streets.
Although, the organizers promised those paper cups were taken good care of and are going to undergo
recycling, trash was still generated. it will take energy and resources to recycle. i'm not going to make judgments
against the organizers since they have definitely have done more work for the environment than i have.
it's just a fair suggestion to orient or remind the runners while they were signing up days before the event to bring their
own water in reusable bottles. people might still forget to do that but it would have helped.
I might be jumping into conclusions here, but some guys thought of a way to get rid of the paper cup problem.
Rodrigo García González, Pierre Paslier and Guillaume Couche created an edible membrane that allows you to drink from a blob. It's inconvenient to sell in the stores as of now but it could work in those events. People would just have to pop them out
to a crowd of runners. Hit or miss the mouth would still be fun. They can get it by hand, too.