Categorical Exclusion Form

National Park Service
U.S. Department of the Interior

Natchez Trace Parkway

Categorical Exclusion Documentation Form (CE Form)
Project: Recurring Paving and Rehabilitation of Existing Roads along the Natchez Trace Parkway PEPC Project Number: 114887
Description of Action (Project Description): This recurring CE covers future paved road rehabilitation projects at the Natchez Trace Parkway (Parkway). Rehabilitation includes the mainline, access roads, interpretive pull-outs, parking areas, bridges, culverts, and associated safety improvements and striping. The Parkway works with Federal Highway Administration (FHWA) to design and implement road rehabilitation projects that range from minor overlays to full depth reclamation (FDR) with culvert and bridge repairs. Recently NEPA updates now allow for a CE to cover the typical actions needed to maintain a safe roadway even with the more intensive construction needed for FDR's, major culvert replacements, and introduction of raised profile striping. However, the NPS and FHWA are still responsible for taking a hard look at the impacts project by project and final construction plans will need to be reviewed by NPS to ensure the associated Section 7 consultation and Section 106 consultation are completed on a project-by-project basis. NEPA and NHPA coordinators shall review all projects to ensure they are in keeping with the activities covered under this CE. Types of activities include:
-Full Depth Reclamation, defined "as a recycling method where all of the asphalt pavement section and a predetermined amount of underlying materials are treated to produce a stabilized base course.(1) Different types of additives, such as asphalt emulsions and chemical agents such as calcium chloride, portland cement, fly ash and lime, are added to obtain an improved base. The five main steps in this process are pulverization, introduction of additive, shaping of the mixed material, compaction, and application of a surface or a wearing course. If the in-place material is not sufficient to provide the desired depth of the treated base, new materials may be imported and included in the processing.(1) This method of recycling is normally performed to a depth of 100 to 300 mm (4 to 12 in)" (Source: https://www.fhwa.dot.gov/pavement/recycling/98042/16.cfm) On previous Parkway projects, FDR has been performed at a maximum depth of 18". At this depth, ground disturbance is well within zones previously disturbed by construction.