As nonpoint source pollution, storm water runoff is one of the main contributors to stream impairment in the United States and is primarily treated using best management practices (BMPs). One of the problems with BMPs is that the properties including the optimal composition and physical characteristics of the media used in bioretention basins are not well evaluated. The objective of this research is to evaluate treatment performance and physical characteristics of different alternative low-cost and/or low-weight media to be used in bioretention basins. Specifically, the use of rubber chips is evaluated as a possible supplemental medium because of their light weight and availability. Four types of rubber chip mediated soil mixtures were tested. It was found that a 50/50 mixture of rubber chips and sand had the best treatment, but lacked the best physical qualities for plant growth and may require addition of compost.