RS&H Endangered Species – DTW Runway 4L

ASTI was contracted by RS&H to assist with environmental clearance for reconstruction of Runway 4L at Detroit Metropolitan Airport (DTW). In addition to conducting a wetland delineation, ASTI provided endangered species survey and clearance services for the proposed project.

Prior to conducting the on-site endangered species survey, state and federal records of protected and rare species known to occur in Wayne County and known occurrences of protected species previously found on DTW property were reviewed. The survey entailed a comprehensive meander search over the entire 775-acre project area to look for protected and rare species. This survey was conducted under endangered species survey guidelines established by the Michigan DNR and in compliance with federal Section 7 consultation.

One area containing a population of three-awned grass (Aristida longespica), a state-threatened plant species, was found within the survey limits. Aristida longespica had been previously found at the airport in areas where sandy soils occurred at the surface, particularly in areas that received regular mowing. This small, slender plant species could easily get out-competed by taller plant species; thus, routine mowing appeared to assist in keeping plant competition in check. No other state or federally listed threatened, endangered, or species of special concern were located within the survey limits. Since this population of three-awned grass was outside the proposed construction area, project clearance was obtained, and the population was protected.