Troubled Waters: Part II – Building the Solution

…continued from part I  

Previously, I described one of the most disastrous installations imaginable: a six-figure residential pool installed in sand on a bluff overlooking the ocean, with no soils report, no foundational structure of any kind, and a system that was basically unconscionable.   

Now, we’ll leave all that bad stuff behind and talk about what we did to set things right, beginning with unceremoniously ripping out the old pool. Because the pool structure was already breaking apart and in such loose soil, it came out with relatively little struggle.  

That left us with a blank canvas and a client whose patience had been pushed to the breaking point. To her great credit, she stayed upbeat about the possibility of having a great pool and enjoying it in the spectacular ocean setting.  

Divine Water 

As I mentioned in part I, the client wanted the very best in terms of the system and the water quality it would deliver. She was intent on having the ultimate bathing experience using her pool and spa combo for exercise as well as hydrotherapy.  

Her specifications were admittedly extreme. She wanted the pool to rise to spa-like temperatures in excess of 90 degrees, which meant the pool’s circulation system had to operate at therapy pool standards with a two-hour turnover and rapid heat rise.  

The pool is 18-by-42 with an 8-by-8 inset attached spa. It has a perimeter overflow lautner edge on three sides and a vanishing edge down the length of the pool on the other. It has a total volume of about 25,000 gallons with the surge capacity handled in two surge tanks.   

The treatment system is the heart of any SRK HydroZone 3® pool. Each one is a little different depending on the client, budget, and the pool’s design. For this pool, we had four separate systems: one for the pool, one for the pool surge, one for the spa, and another for the spa surge tank. The pool system has a 50-gram, skid-mounted ozone system with a medium pressure UV system. The spa has a seven-gram ozone system with a medium pressure UV system, as well. All have custom-made, high-flow contact tanks and chemical controllers to help control pH with independent C02 gas feeds with static mixers for good gas absorption. The pool has two high-efficiency boilers with two heat exchangers, and the spa has one boiler with one heat exchanger.  

In all, the pool has a two-hour turnover at 450 gallons per minute (GPM) overall flow rate.   

Like all of our pools, the circulation system is designed for efficiency with mostly 4-to-6-inch plumbing and floor returns, which are installed in a recessed “toe-kick” detail that encircles the bottom of the pool. The returns are plumbed on a 4-inch plumbing loop with 1-inch drop lines every six feet, all to ensure even distribution and flow throughout the entire vessel. The skimming action is handled by the lautner and vanishing edges. As is true of all our designs, removing that top inch of water as rapidly as possible plays a major part in ensuring superior water quality and efficient operation.   

I cannot emphasize enough how important water quality is to this client. She uses the pool every day, and from the start, she’s insisted on impeccable conditions and elevated temperatures. That didn’t happen with the first pool, and it has been a truly wonderful feeling to be able to finally deliver the finest level of aquatic experience. She told us that she cried when she first saw and then used the new pool.  

Ultimately that’s what HydroZone 3 pools are all about.   

The Sand Trap 

The other part of the happy ending involves the pool structure. We had two basic challenges. First, the soil is essentially sand and uncompacted fill, with competent, load-bearing soil down about 16 feet. That meant we’d need some kind of substructure and a heavy-duty pool shell that would essentially exist freestanding in the constantly shifting soil.  

Second, we had to work within a tight area due to environmental setbacks that protect the sensitive sand-dune landscape. The original pool was actually built partially over the setback lines, so on top of everything else, the first pool was illegal. In fact, its equipment was set even farther out on the dune. So, with the new pool, we had to move it back within the easements, find a new place for the equipment, and engineer a foundation capable of supporting the structure in the existing soil conditions.  

Those issues set the stage for a truly ingenious solution, if I do say so myself. We decided to locate the equipment underneath the pool in a large reinforced vault, spanning the entire length of the pool, that also serves as a massive footing. It’s a massive affair, 20-by-20 feet in two separate rooms, distributing the weight of the pool.  

In keeping with our standard practice, we over-excavated the site and built rock-solid forms. It was extremely precise work forming the pool and installing the steel and plumbing due to the tricky lautner edge, vanishing edge trough, and unusual “Moses” trough that separates the pool and the spa.  

The equipment room is accessed by a flight of stairs that descends beneath the narrow deck between the pool and the back of the house. With its 7-foot ceilings, ventilation, and easy access, the equipment rooms are comfortable and even welcoming. And, with their deep subterranean location, there is zero noise.  

Back up top, the pool is finished with black Absolute Granite and a dark Pebble Fina polished aggregate finish, all beautifully lit with LED lights. It’s a beautiful complement to the contemporary minimalist architecture of the home – and it is, quite literally, a perfect example of a modern pool solution!