LNAA, on behalf of FAA, retained RETTEW to complete the Section 106 process, beginning with a windshield survey to identify all buildings older than 50 years in the area of potential effects. Following concurrence from the Pennsylvania State Historic Preservation Office (PA SHPO), RETTEW evaluated 36 potential historic resources to determine their eligibility for listing in the National Register of Historic Places (NRHP), and one farm was recommended eligible. Similarly, during the Phase I archaeological survey, RETTEW identified nine historic archaeological sites, and one site was recommended eligible for NRHP listing. RETTEW coordinated with PA SHPO, consulting parties, FAA, and the client to execute a programmatic agreement that would mitigate the adverse effects of the project on the two eligible resources we identified. The mitigation efforts included retaining all historic buildings and incorporating landscape buffers to shield the farm from the proposed development. In addition, RETTEW collaborated with PA SHPO to develop a tool for evaluating the NRHP eligibility of individual barns. To mitigate the adverse effects to the archaeological site, RETTEW conducted intensive data recovery excavations that yielded more than 20,000 artifacts ranging in date from the late 1700s to the mid-1900s.
Under the Department of Transportation Act of 1966, FAA had to demonstrate there was no prudent or feasible alternative to using the NRHP-eligible properties and the project would minimize harm to the property. In collaboration with LNAA and FAA, RETTEW prepared a Section 4(f) statement to document these stipulations. Building upon the work completed for the Section 106 and 4(f) processes, RETTEW worked with LNAA to complete the cultural resources sections of the Environmental Assessment required for NEPA compliance.