Print Version: Design Food For Thought

Design Food For Though
Floating some Food for (Design) Thinking
by Bob Kappel

In an attempt to jump-start conversation and perhaps even spur change in our industry, I offer up the following for your consideration:
1. Ban the reuse of unfiltered and untreated balance-tank/surge-tank water for sprays, features and slides.
It is understood that a surge tank in any given system collects the dirtiest water in the pool. In the case of spray pads, it is the only point of water collection. A filter pump draws water out of this tank for treatment through the filter(s), any heater(s), past chemical injection points and perhaps even through a UV or ozone system. The turnover rates are carefully calculated to meet code and the sizing of the system’s components are chosen accordingly. The design is then approved via a state and local plan approval processes.

The problem that occurs (and I believe that it is an under-considered issue) is that in a system where the feature/spray/slide pumps are designed to draw water from the surge tank, and they are turned on, the turnover rate is significantly altered to the point where the original design point for turnover is no longer valid and the treatment system is rendered too small. In essence, water is short-cycled and does not get properly treated. Furthermore, this unfiltered and untreated water is aerosolized in features, slides and sprays. These aerosolized water droplets contain a witch’s brew of contaminants that has to date been neither qualified nor quantified. It is my opinion that chloramines are the least of our problems in this case, and that a whole host of disinfection byproducts (DBPs) and organic compounds are absorbed or breathed in by patrons. (Don’t even look up Naegleria Fowleri on Wicopedia!)
In laymen’s terms, untreated bathwater is sprayed into a fine mist and breathed in by swimmers. This undoubtedly causes illness. It’s time that health codes make it mandatory that aquatic play systems are designed to draw feature/spray/slide water from the pool itself. In cases such as spray pads, where there are no other water sources to draw from, an additional tank in which the filtered and treated water collects must be designed into the system. The feature/spray/slide pumps can then draw clean, treated water for use.

Mandate Nationally Recognized Certification for Aquatic Facility Operators.
While some states and local authorities require operator “certification”, many do not. As we all frequently see, unqualified operators place the public’s health at risk. This is clearly unacceptable, and regulatory bodies need to step up to the plate and require pool-plant operator certification just as is required of wastewater and drinking water plant operators.
While recognized certification may not be a cure all, it is a solid step in the right direction.

3. Design HVAC and Filter Systems That Adjust According to Bather Load.
Too many times, I see indoor facilities that are wasting enormous amounts of energy and money because their HVAC and filter systems only have one speed: “On”. This “one-size-fits-all” design strategy desperately needs modernization. This necessity is dictated by equal parts energy conservation, high utility costs and patron/employee comfort and health. Most facilities have patron loading conditions that can be broken down into three basic categories or use levels: Light, Normal and Heavy. In situations where an indoor facility is lightly loaded or not loaded at all, it would make sense for a savvy operator to have the ability to ramp down the HVAC and filter systems, still conserving energy while meeting established air and water quality parameters.

Taking this to the next logical step, it would make sense for an operator to be able to ramp up the HVAC and filter system in cases of unusually heavy conditions, compensating for the heavier organic loading. Utilization of modern building control systems and variable frequency drives puts this in easy reach of any designer. It is understood that these controls, VFDs, larger filters, larger HVAC systems and larger piping, all associated with such a plan, are initially more expensive; however it makes sense for owners and designers to plan for these extra up-front costs of such a system to greatly improve the conditions for patrons and employees. Perhaps they’ll even minimize their own exposure to litigation arising from poor indoor air quality – a situation which seems to be increasing in our industry. ~ RC