A water and sewer utility in the southeastern United States faced the prospect of spending $42 million to replace a 4,800-foot 28-inch steel force main that had been malfunctioning for three years.Believing there must be a better way, the agency’s engineering consultants brought in AET Robotics & Inspection Services to diagnose the trouble. Using a special float rig with CCTV cameras and laser and sonar profiling, AET, based in Clemson, S.C., inspected the pipe from end to end as it ran 75 percent full of wastewater.The investigation found the problem: a contractor using horizontal directional drilling (HDD) had bored clear
