One of the biggest environmental problems today is plastic pollution. 70-80% of plastic in the ocean is streamed in through rivers.
Since it'd be a little harder to prevent deforestation or melting ice caps by a simple geocaching event, the least we can do is collect some garbage around the Poleg river basin.
Taken from: https://oneworldoneocean.com/blog/the-plastics-breakdown-an-infographic/
I'll supply trash bags and gloves.
I chose early morning to avoid the heat but if there's general agreement, I can postpone it to a later hour.
P.S. Feel free to bring friends and family, and maybe make a beach day out of it.