An interesting service call recently. The customer said that an area of about 20 square yards was bulging up like a water bed. This was an industrial complex with 2" main irrigation pipes. They had shut off the water and let it settle for a week before calling me. On this Friday afternoon, it was still very soggy. I suggested that we give it until Monday to dry out a little more before turning the water back on to find the water leak. I then got the idea to poke holes while it was still soggy that might let the water escape on Monday. I took a steel rod and made a matrix poking a hole every two feet. The ground was swelling because just like the clay soil keeps the water from penetrating deep, it was keeping the water from coming to the surface. A large area like this could have taken a long time and lots of digging to find the source. On Monday I turned on the water and started walking off the area. I immediately found water gushing out of one of the holes I had made. I stuck in my shovel to mark the spot and ran to turn off the water. I cut out a piece of sod and found a flow of water. I stuck my arm down and could feel a broken pipe. The customer had recently had heavy equipment out there repairing a sewer problem and the weight of the equipment in wet soil had broken the pipe. I dug it out and cut off the broken elbow. I also noticed some movement and found the lower fitting, while not broke, was not holding. Gluing that fitting, replacing the broken elbow, and connecting the pipe with a compression union solved the problem.