Monitoring the Start up of a Three-Cell Denitrifying Bioreactor.

Denitrifying woodchip bioreactors are sized to treat a portion of subsurface drainage flow from a given system.  Over sizing them can create conditions under which unintended consequences could occur.  A potential solution for treating additional water is to use a cascading series of bioreactor cells that come on line as overflow is initiated from the previous cell.  A three-cell biorector of the described design has been engineered, installed, and operated in southern Minnesota on a 277-ha watershed.  This presentation will highlight the instrumentation and early flow and water quality results from the first few months of operation.