When the Iowa State Fair opens in Des Moines today, fairgoers will have the chance to take part in a new version of the “three r’s” — reduce, reuse and recycle. The Iowa Department of Natural Resources is launching a recycling project for the 11-day event which should generate tons of trash.Jeff Geerts, a D-N-R program planner, says number-one plastic will be collected in the main food vendors area, things like water bottles, sport drink bottles, and cups for beer and soft drinks. Geerts says 100 big green recycling barrels will be set up to collect the tons of trash.Geerts says a study has found about 21 tons of the garbage generated at the state fair is number-one plastic. The project’s goal is to collect ten to 15 percent of that trash to keep it from landfills — that’s more than two-tons of plastic bottles and cups.The D-N-R will have an exhibit at the fair called the Tower of Trash, representing the amount of garbage the average Iowan generates in a year. It is ten feet long, six feet wide and 13 feet high.