An escaping pressurized water jet underground can produce a faint noise that may be muffled on its solution to the floor. Utmost signal could be picked up above the leakage position. Some forms of gases escaping from the pipeline will create a range of sounds. They have leak testing devices https://leak-finder42085.activoblog.com/34027321/5-easy-facts-about-underground-pool-pipe-leak-detection-described