Sweet set up. I use a wide landscaping rake quite a bit in my business for removal. I like the foam add. If you had access to one of those floating barriers like they are using in the gulf I'd imagine you could direct almost all of it into your take up. As it stands, how much are you removing in a 8 hour day per surface acre? I also have used a lot of trash pumps in my time, would like to see some photos of that screening set up.
