Leaky pipes
Water loss can also occur when there are holes in the jet or skimmer lines and fittings, or in mounting plates and light fixture openings at or through the pool wall, too. Therefore, service professionals should not jump to any firm conclusions. For example, standing water can drain back through the lines until the water level reaches a point that is lower than the leak where it will stabilize.
If the pool is equipped with a bottom drain, then its seal to the liner or even the plumbing line running back up to the skimmer/pump can be at fault. For test purposes only, an overturned bucket can be placed on top of the pool’s bottom drain (using a weight to hold it down), to stop any water from seeping out. This allows the service professional to investigate other possible areas where a leak might be present.
Of course, there can be more than one leak, but the liner is always the first and is usually the easiest to identify or rule out as the likely source. As part of these preliminary tests, a quick visual inspection of all the equipment located above ground (i.e. pump, filter, heater, and visible hoses) should be performed. For instance, a leaky pump gasket seal or fitting can be the culprit and can be missed if these preliminary checks are not completed.
Case in point
For example, on one particular service call, this author located two leaks in the jet lines beneath the deck of an older (30-years plus) residential pool. It had a simple, standard layout of two jets, one skimmer, and a filter and pump located in the homeowner’s garage approximately 9 m (30 ft) from the pool.
In this case, the homeowner inherited the pool after purchasing the property and suspected a leak was present during the first year of operating the pool. During this period, they had already determined the leak was in the supply/return lines and not the five-year-old vinyl liner.
After the preliminary checks were performed, it was time for a professional to inspect the pool’s underground system. This is where the real detective work begins. The primary tools comprise a suite of underwater video cameras (to inspect the underground plumbing internally) and sophisticated listening devices (which are attuned to capturing the unique sounds produced by water as it leaves the pipes into the surrounding soil).
The real investigation begins
Using cameras and microphones, the investigative plodding begins. This first involves inspecting each line internally (where possible) via camera—from the pool to the pump—looking for any obvious problems. For example, any signs of breaks in the line caused by a stone that has gradually worked its way through the pipe wall, or splits or broken fittings (such as tee and elbow joints, or line connectors).
The exact location and depth of the pipe run and its fittings is also determined with the use of specialized locating equipment that reads a signal transmitted by the camera when it is inside the pipe. This allows the technician to flag the lines above ground on the grass or garden areas and outline them in chalk on the pool deck as they travel underground.
In doing this, when the precise location of a leak is identified and confirmed after using the cameras and microphones, these marked locations play a factor in determining what is causing the leak, as well as what recommendations can be offered to the homeowner with respect to the repair. In some cases, landscaping might have damaged a line or ground settlement could have occurred, resulting in surface cracks in the pool deck.
During this service call, the author found three such possibilities: two confirmed beneath the deck and one suspected under the lawn.
