The first step in the swimming pool leak detection process is at the initial phone call between the swimming pool owner and the pool leak detection company. During this phone conversation, the leak test company will ask several questions to help determine the appropriate course of action and to provide you with an estimate. Questions that may be asked include: “When did you first notice that your swimming pool had a leak?,” “Does the water-level stop at a certain point in the pool?,” “Does the water still leak with you swimming pool pump in the off position?,” “How many returns, drains, skimmers and lights does your swimming pool have?,” “Is the water clean and clear?”
Based on the questions above (and a lot more other questions), the professional leak detection will give you an estimate for your leak detection.
Upon arrival of the leak technician, the process will usually involve two types of tests: 1) pressure testing of the return lines and suction lines; and 2) structural test inside the swimming pool shell.
Pressure testing consists of the technician plugging your plumbing lines and inducing water into the plumbing. A pressure gauge on the pressure testing rig will allow the technician to determine if there is a loss in pressure (indicating a leak) in the line or if the pressure holds (indicating no leak at this line). The technician may find that the leak is in the return line or the suction line or both.
Pin-Pointing the Location of the Leak in the Swimming Pool Plumbing
Once the technician has determined that a leak exists in the plumbing line, they may use two devices to “pin-point” the general area of the leak so that the repair can be direct and without waste in time and expense.
If the leak is rather large and likely in/under the soil, the technician may induce compressed air into the plumbing line. They will then use an electronic listening device to listen for loud or an unusual bubbling sound. The technician will generally mark this area with tape so that the owner or company performing the repair knows where the leak is located.
If the leak is small or not located in/under the soil, then helium detection may be used by the technician. When detecting for these types of pool leaks, the technician will induce helium gas into the plumbing lines. Then they will canvas the pool and equipment area to look for high levels of helium indicating the location of the leak. The tool for this is called a helium detector. Once the area is discovered, the technician will mark such area so that other will know the location of the leak for repair.
Structural “Static” Tests
If no loss of pressure is found in the swimming pool plumbing, then the technician may decide to move forward with a structural test. This is where the technician will dive your swimming pool and use dye to determine if any areas inside the pool are pulling the dye (indicating a leak). The dye used is a special purple or green/yellow dye in a syringe with a very small capillary tube so that a tiny ribbon of dye can be ejected and movement of the dye can be observed.
Common areas that are dye-tested include but are not limited to: lights, returns, skimmers, skimmer throats, vacuum fittings, anchor fittings, tile joints, cold joints, main drains, hydrostats and more.
Once the areas of leak have been located the technician will inform you of the location of those leaks so that they can be properly repaired.
The structural tests often involve divers that use compressed air to be able to properly perform these tests underwater.
If the water is cooler, the diver may use a wet-suit and if the water is cold the diver may be equipped with a dry-suit for cold water diving.
*This article is in reference to concrete swimming pool leaks.