The issue of dealing with storm runoff from impervious surfaces has put forth the need for best management practices. One of the methods for controlling runoff is rain gardens or bio-retention basins. These systems can be gardens of plants like wildflowers, trees, woody shrubs or grasses that utilize the microbial, chemical and biological properties for removal of pollutants from the storm water runoff. Because the process is relatively new, there has been some controversy over the soils used in bio-retention systems. Some engineers have determined that the soils must drain at a rate of 2 to 4 inches per hour to provide enough ponding time (24 to 48 hours) to remediate nutrients and other contaminates.