At the country club, tens of thousands of dollars had been spent rectifying the leak, only to accomplish stemming the loss of water without truly fixing it.
Finding all the issues
The author’s company became involved in the situation in fall 2022. They met with property management and gave them an initial price range to come and conduct leak detection on the gutter pool.
First, the company performed a visual inspection, while speaking with maintenance staff to get as much background information as possible. The staff explained the pool was losing roughly 152.4 mm (6 in.)—or 59,430.9 L (15,700 gal)—per day. Next, the company performed a static leak test. This included bringing the waterline up to the spill level of the pool, shutting off the makeup water supply, affixing a measuring stick to the side of the pool, and creating a log form for maintenance staff to record their findings.
The pool was checked every four hours, to determine how quickly the water level was falling. It was determined it was losing a tremendous amount of water within the first 12 hours, followed by more gradual loss afterwards. This indicated there was a major leak at or near the gutter, as well as smaller leaks below that spot.
At that point, the company pressure tested all the waterlines going to and from the filter room. There was one minor leak in the gutter line, which was the result of a makeshift repair. All the other lines were intact.
Next, they conducted a dye test of all the main drains and other shell penetrations. This uncovered more problems, mostly notably that all the light niches leaked. The pool water was pumped down to access the niches, but in doing so, the team uncovered another problem. As the water was pumped out and allowed to spill over the concrete decking, it would run back into the pool below the stainless steel gutter. It appeared as though the water was running through the damaged decking and returning to the pool between the gutter and the shell.
After seeing this happen, one of the facilities maintenance staff members explained every time it rained while the pool level was down, he would witness the water level rise, and the water seemed to come from below the gutter. After dumping 18.9 L (5 gal) of yellow food colouring onto the deck and spraying down the surface, their fear was confirmed. The food colouring began entering the pool. Not only was the joint between the shell and gutter compromised, but the shell had also most likely not been properly backfilled with permeable material.
