This project required intensive labor and unavoidable traﬃc delays, as 12.5 of the 26 miles of gas lines were located underneath roadways. First, the sites were excavated to expose the underground pipes, and bulkheads built for the cellular concrete placement points approximate-ly every 1,000-1,500 feet. Then, between three and six days after these grout points were excavated and bulkheads built, the specialty contractor pumped cellular concrete into the gas lines, making sure they were completely ﬁlled. The construction team from Gibson Pressure Grouting designed, mixed and pumped 6,500 cubic yards of cellular concrete, ﬁlling approximately 12.5 miles of gas line in 30 working days. Gibson Pressure Grouting chose to use AERLITE-iX to ﬁll the gas lines, as it would provide the 40 pcf density and minimum 125 psi compressive strength required by the Georgia Department of Transportation. The strength of the cellular concrete was essential to the successful completion of this project, and wet density veriﬁcation testing was performed every 15-20 cubic yards to ensure the cellular concrete met these requirements.