Location: Camp Lejeune, NC Overview: RyanGeo completed the abandonment of 1,400 linear feet of stormwater pipe at Camp Lejeune under challenging and highly uncertain subsurface conditions. The project required extensive pre- planning and coordination to address the risks associated with severely deteriorated infrastructure and unknown void conditions. Challenge: The large-diameter stormwater pipe had deteriorated to the point that its structural integrity was significantly compromised. Many pipe segments were found to be approximately 50 to 80 percent filled with silt and sand, indicating long-term failure and limited remaining hydraulic capacity. These conditions also increased the likelihood of voids forming beneath and alongside the alignment. Restricted base access requirements and logistical constraints further compounded the complexity of the work, making detailed contingency planning critical prior to mobilization. Solution: RyanGeo worked closely with the project team to develop a comprehensive abandonment plan that accounted for multiple potential field conditions. Following an initial day dedicated to base access coordination and logistics, the stormwater line was successfully abandoned on Day 2 using 430 cubic yards of 30 pcf Low-Density Cellular Concrete (LDCC). The high flowability of LDCC allowed it to encapsulate debris-laden pipe sections and migrate into surrounding voids, while its low unit weight minimized risk under unpredictable subsurface conditions. Results: • Total Pipe Abandoned: 1,400 linear feet • Material Placed: 430 cubic yards of 30 pcf LDCC • Pipe Condition: 50–80% silt and sand accumulation in multiple segments • Execution Timeline: Pipe abandonment completed in one day following access coordination • Key Benefit: Reduced risk through proactive planning, communication, and material selection