I understand what you're saying. Ever see that little river that flows behind the zoo in San Jose?
It's disgusting. 
Keeping the streets, rivers, etc. clean in Costa Rica doesn't seem to be much of a priority. I cringe every time I see a tico littering in the streets, as if it is the "OK" thing to do. Indeed, once while I was walking back from the Ch*ldren's Museum with a chica friend and her little daughter, the daughter dropped a soda can and candy wrapper onto the sidewalk. I corrected her, telling her she shouldn't litter and we picked it up and deposited it in the trash. I told her mother that it has to start somewhere, though the mother seemed to have little interest.
Come to think of it, I often see gringos littering in San Jose....they should know better.
Zebra