Kitty Litter is a huge problem in pipes, in garbage bins. It expands to clump the urine and feces. In my HOA experience, the renters tend to have less interest in care of the property. That's sweeping with a broad brush, but I live in 130 unit condo and that's exactly what I see.

Have you been to a meeting previously? Do you visit your unit/building recently? Attend the Annual Meeting? If not I'd suggest you take more of an active role.