News & Notices
The CICEET-sponsored University of New Hampshire Stormwater Center has published its first year of field data. The 2005 Data Report evaluates the effectiveness of 12 stormwater treatments in protecting water quality and reducing runoff. You can browse the report online:
http://ciceet.unh.edu/news/releases/stormwater_report_05/
This report is intended as a resource for land use decision makers who must comply with Phase II of the Clean Water Act. Under these regulations, U.S. communities with a population of less than 100,000 are charged to develop more effective stormwater management programs.
The center�s field site is unique in its capacity to test stormwater treatments, side-by-side, under strictly controlled conditions. There, researchers have evaluated three classes of stormwater treatments: manufactured devices such as underground infiltration units and hydrodynamic separators; traditional, structural approaches such as swales and ponds; and Low Impact Development designs (LIDs) such as a biorentention system and a gravel wetland.
The analysis revealed distinctive trends. As a group, LIDS exhibited the highest pollutant removal efficiency, while the performance of manufactured devices varied. Traditional approaches, such as a riprap swale, did poorly to moderately at best. Certain design elements, common to several systems, exhibited the most effective pollutant removal. These included infiltration and filtration mechanisms, large storage volumes and residence time, and dense root mats and herbaceous plants to absorb pollutants.