Exfiltration trench for post construction storm water management for linear transportation projects

ODOT is required by the Ohio Environmental Protection Agency (OEPA) to implement post-construction storm water Best Management Practices (BMPs) for linear transportation systems that are sold after March 10, 2006. Several BMPs are candidates for this application (Vegetated Bio-filters Devices, Infiltration Devices, and Detention Devices). Of these the Exfiltration Trench Infiltration Device appear to be an attractive choice due to manageable construction costs and constructability and ease of maintenance and operation but, design optimization and performance verification are needed. STUDY OBJECTIVES: The objectives of this research will include: 1) examining the design, durability, and construction of the Exfiltration Trench; 2) proposing revisions to the Exfiltration Trench to provide an optimum filter medium design to capture the first flush; 3) developing a maintenance manual; and 4) examining any and all possible safety concerns.