Boot Road Geophysical Result Summary

Boot Road Geophysical Result Summary
August 23, 2019

Below for your information is a summary of the results of a geophysical investigation performed within a 250-foot section of Boot Road near Carriage Drive in East Goshen Township, Chester County, on June 22, 2019, by RETTEW Associates, Inc., for Sunoco Pipeline, L.P.

The PennDOT District 6 Geotechnical Unit and its consultant, Schnabel Engineering, reviewed the RETTEW report, and concur with its conclusion based on the information and documentation provided from the June 22 investigation. RETTEW sees no evidence in the data that indicates the inadvertent return at the location of a utility trench on Boot Road near Carriage Drive caused any subsurface impacts or subsidence.

This initial geophysical investigation found nothing under Boot Road that requires immediate remediation. The department will continue to monitor the roadway.

The investigation did identify “anomalous zones” underneath Boot Road at this location that may be related to saturated soils in the area of utility trenches.  Anomalous zones are areas where something unusual was detected. An anomalous zone does not necessarily indicate something is wrong, but that something is different from normal.  This area warrants further attention.

As part of PennDOT’s request for a geophysical investigation of a larger section of Boot Road, Sunoco Pipeline, LP agreed to perform two additional geophysical investigations of all lanes of Boot Road from Carriage Drive to Wilson Drive using Ground Penetrating Radar. The first investigation will be conducted soon, following the receipt of a PennDOT Highway Occupancy Permit. The next investigation will be done following the completion of pipeline work on Boot Road.

PennDOT supports this approach to perform the two additional GPR investigations to identify any changes in subsurface conditions from the time when work is taking place on Boot Road until the work is completed.

Based on the outcome of the next two GPR investigations, the department will determine whether to take an additional step to further investigate subsurface conditions at a specific location. This could involve excavating a hole or trench or performing test borings.