Langley Air Force Base (AFB) covers approximately 3,000 acresincluding 600 acres of wetlands just north of Virginia Beach,Virginia. The base has a rich military history dating back to 1916 and has remained acritical part of the United States military infrastructure. Rehabilitation on the base was necessary due to the stress onits physical infrastructure, especially its aging water system.There is a great deal of space for mission activity and the watersystem that supports that activity but maintaining operationswhile addressing critical upgrades is essential. Typically, agingpipes would be dug up and replaced in kind. However, currentenvironmental concerns as well as disruption of base activitywould not allow this approach. To minimize environmentalimpact and operational disruption, Fusible PVC® pipe, installed by horizontal directional drilling was used to rehabilitate the line.