Addendum Phase I Archaeological Survey of the I-285/I-20 Interchange Reconstruction and Widening Project, Fulton and Cobb Counties, Georgia

New South Associates, Inc. (New South) conducted an addendum Phase I Archaeological Survey for the Interstate (I)-285/I-20 Interchange Reconstruction and Widening Project (GDOT PI 0013918) as part of the Major Mobility Investment Program (MMIP).  The project proposes to reconstruct and widen the I-285/I-20 West Interchange in the City of Atlanta, Fulton County, Georgia, to provide operational improvements at the interchange and along the approaches on I-20 and I-285.  The proposed improvements include construction of collector-distributor (CD) lanes along I-20, construction of additional lanes on I-20 and I-285, and the reconstruction of the interchange ramps to improve traffic operation and safety.  The purpose of this addendum Phase I Archaeological Survey was to locate and evaluate the National Register of Historic Places (NRHP) eligibility of archaeological resources, pursuant to Section 106 of the National Historic Preservation Act (NHPA) as amended.

This addendum follows an earlier Phase I Archaeological Survey that New South completed for the planned undertaking (Dorland et al. 2020). This prior Archaeological Survey covered an Environmental Survey Boundary (ESB) that was designed to encompass all areas of possible ground disturbance that could result from the undertaking, including existing and proposed right-of-way (ROW) and all necessary easements, along with an additional 100-foot (30-m) buffer.  Total acreage for the original ESB measured 641.5 acres (259.6 ha). 

Plan development has progressed since the original survey and an area of potential effect (APE) has been defined for the project that includes all existing and required ROW and easements within the project limits.  Four addendum survey areas were identified requiring additional archaeological evaluation.  Design changes since the prior survey resulted in the addition of two addendum survey areas, a 15.0-acre area to the north and a 10.8-acre area in the south, that required surface and subsurface archaeological survey.  The northern area encompasses a 15.0-acre portion ahead of the relocation of the Georgia Power Transmission utility corridor. The southern area is a 10.8-acre section that is needed to accommodate proposed modifications to the interchange loop on-ramp to I-285 from State Route (SR) 139/Martin Luther King Jr. Boulevard.  An evaluation of prior coverage also identified two addendum survey areas where the APE extends outside of the original ESB, but did not require shovel testing due to their proximity to prior survey coverage.  Western addendum survey Areas One (0.3 acres) and Two (0.06 acres) were necessary because the ESB for the initial survey did not encompass the full extent of existing ROW and required surface reconnaissance and photo-documentation during the current survey.  An expanded survey corridor (ESC) was not included as part of the addendum survey areas, as the limits of the design changes are considered well-established and unlikely to change.

Four isolated finds were identified in the northern addendum survey area.  Isolated finds are ineligible for the NRHP.  Also, previously recorded site 9FU799, representing the remains of the ABC Compounding Co., was revisited.  This site was recorded during the original Phase I survey for this project and, while the site was found to lack data potential and integrity within the ESB, it was recommended as having an overall unknown eligibility under Criterion D because it extended outside the ESB and could not be fully delineated. An environmentally sensitive area (ESA) was recommended for the unknown portion of this site to protect it during construction.  The current investigation fully delineated the site in the northern addendum survey area and indicated it has a low potential for significant historic archaeological data.  Based on this result, site 9FU799 is recommended ineligible for the NRHP under Criterion D and it is recommended further that the ESA be removed from project plans.