What do you mean polluted at Horn? Water color or a lot of trash around? The water there is naturally a tea color. The shoreline trash sucks and unfortunately is way too common around the urban ponds. Horn has some nice fish in there. I don't trout fish, just bass, but they do stock Horn twice a year and put salmon in when they have em.
It was actually the stench on my hands and on all my lures that stunned me after fishing there. When I looked into the purity of the water I read some really shocking stuff, among that was YouTube videos of raw sewage overflowing into the pond.
It IS a BEAUTIFUL area and I know there's lots of fish there! I would fish it again for those reasons, but wouldn't be so keen on keeping any trout from there if I caught em. And I'd have to be prepared for that distinct & pungent smell all over everything again. This was after fishing the calmer side west of the walkway due to strong winds pummeling my face and bad placement on my part that day. That's when I learned to always check the wind speed and direction for where I plan on fishing for the day.
I'm not trying to be the Debbie Downer on a very popular spot. It's just important information if I'm planning on eating any trout I catch.