Would this be an ongoing availability or just this weekend? Cause there's plenty of non profits that are looking for volunteers but they generally want consistent, long term ones, not just one time drop ins.

Congressional Cemetery does drop in grave clean up throughout the summer but I don't think they've started that quite yet this year.

City Wildlife is always looking for folks, but they generally want long term volunteers. If you've ever wanted to bottle feed a baby squirrel, this is the place lol.