Two grassed bioretention cells were installed at Graham High School in Summer 2005. They treat a 1.73 ac drainage area that is 40% impervious. These are the first grassed bioretention systems studied in North Carolina. Hydrology and nutrient reduction data have been collected at each cell. The project was funded by a 319(h) grant provided by NC DENR to the Piedmont Triad Council of Governments. Results from this study are found in Ms. Elodie Passeport's M.S. Thesis and in Passeport et al. (2009) [Journal of Irrigation & Drainage Engineering].

Monitoring Period: April 2006 - September 2007

Media Depth: North Cell - 2 ft; South Cell - 3 ft

Media Characteristics: 80% expanded slate (Carolina Stalite), 15% sand, and 5% organic matter (yard waste)

Drainage Configuration: internal water storage (IWS). Depth of IWS: North Cell - 1 ft; South Cell - 2 ft

In-situ soil: North Cell - loamy clay; South Cell - sandy loam

Vegetative Cover: bermuda grass