Rules released by EPA in 2003 require beef feedlots defined as Concentrated Animal Feeding Operations (CAFO) to control rainfall runoff from their feedlots. The rules included verbiage that allowed for the design and use of “Alternative Technologies” and require that any “Alternative Technology” be modeled to show they are at the least as effective as traditional storage systems. The objective of this project is to evaluate, through field monitoring, the performance of vegetative treatment systems (VTSs). Six Iowa beef feedlots are being monitored, and through additional funding and partnering organizations, four other sites are being monitored in Nebraska, Minnesota, and South Dakota. Results from the Iowa sites thus far have shown nutrient mass release reductions 40 – 99% as compared to a settling basin only system.