That's because i'm sure many people are from South Philly.
As said above me, you can't stop that. You can't stop certain people from coming to the park. If they wanna come, which they will, they are allowed. You can't deny a guest entrance because of the way they look or are acting, unless they cause harm in someone or something else. Although about the peeing in the sink, gross, and that is something they need to do something about, cause i'm sure that isn't the only time that has happened,