In the hills of northeast Tennessee sits the Holston Army Ammunition Plant, a highly secure facility tasked with manufacturing a wide range of explosives for the US military. WGI was contracted to investigate an intricate array of filtered and unfiltered water facilities that provided fire suppression systems for the facility.

Under an agreement with ARCADIS, WGI performed 91 ASCE 38-22 Quality Level A investigations (test holes) on approximately 22 miles of mains at predefined locations. Out of the 45 locations, larger test holes were performed to widen the holes to allow for ARCADIS to perform broadband electromagnetic (BEM) testing. BEM testing requires a probe to be placed on the outside of the pipe to measure material loss that would impact the integrity of the pipe. The location of these holes and the coordination of testing were required to ensure the pipe was adequately exposed, testing was promptly performed, and the test hole was safely filled.

WGI performed ASCE 38-22 Quality Level B investigation with the Impulse Radar Raptor 3D multi-channel GPR. We were tasked with scanning 27 unique locations on both filtered and unfiltered mains. Over 120 scans were performed in these locations, ranging from 5,000 sq feet to 500,000 square feet each. Finally, WGI also performed validation of horizontal valve locations on each of the main systems with over 400 valves surveyed and uniquely attributed for GIS database updates.

WGI faced many challenges with the successful execution of the project. Due to security at the facility, our crews were always escorted. To reduce the time required for escorts and to properly facilitate BEM testing, WGI mobilized numerous crews to work concurrently, and all work was performed within a 3-week period. Complicating communication, SUE field staff were not permitted to have mobile phones. Pictures of test holes were taken with digital cameras with a modified field of view, and pictures were reviewed by security at the end of each day. Finally, there are numerous hardened explosives manufacturing plants are stationed around the facility. While in service, no work could be performed within a predefined radius. Therefore, the field activities had to be carefully planned and executed to ensure no loss of time and to guarantee our team’s safety.