Beating Pool Drain Entrapment With Proper Plumbing
18 Oct Beating Pool Drain Entrapment With Proper Plumbing
by Eric Herman
With the summer of 2011 and the great drain recall in the rear-view mirror, issues surrounding suction-entrapment accidents continue to challenge the pool and spa industry. Here senior editor and long-time industry observer Eric Herman raises some lingering questions and applies a helpful dose of common sense in an attempt to find a measure of clarity amid a decidedly confusing set of problems.
It’s a subject that continues to dominate discussions in the pool and spa industry and cause no small measures of grief and frustration along the way. Any way you slice it, suction entrapment is a serious problem and until these incidents are completely eliminated, our industry is going to bear the stigma that comes along with it.
It’s been nearly four decades since the CPSC began tracking entrapment accidents and about the same amount time since the first studies of the problem were conducted. Now after all that time and in the wake of VGB and more recently the CPSC’s recall of drain covers and its recent reversal regarding reliance on unblockable drains, the industry continues to grapple with the issue.
We continue working to understand the complexities of the requirements called out in the legislation, struggling to comply with the recall and now facing potential widespread renovations of single-suction plumbing configurations in commercial pools. All the while, we continue to hope and pray that no one ever again is entrapped, entangled or eviscerated in a pool or spa.
In what is already a tough time for the industry because of the economy, the vexing issue of entrapment prevention has made things even tougher. In all fairness, however, there are those who point out that renovation work stemming from VGB requirements has helped some servicers and builders when they needed it most. Wherever they stand on the issue, no doubt most people would agree that if the measures in VGB or the CPSC’s recent moves prevent these horrific incidents, then it’s more than worth the trouble. How effective they will be ultimately remains to be seen, however, especially given the random and scattered nature of entrapment incidents.
At this writing, there has been no reported entrapment death since VGB went into effect nearly three years ago.
With all of that as a backdrop, rest assured I’m not going to revisit the entirety of the requirements in VGB or the history of the act, both of which have been covered extensively in the pages of this magazine and others. I do, however, want to pinpoint a couple of issues that remain puzzling in some respects, and also might point to simplified solutions in others.
The No-Drain Solution
One of the ideas that have emerged in recent years as a result of VGB and the overall push to eliminate entrapment incidents is to simply get rid of drains. After all, you cannot become stuck on a drain that does not exist. In the place of bottom drains, you might have floor returns that take care of circulation concerns and probably do so more effectively, while the suction is handled entirely by skimmers.
Despite the inescapable logic behind the no-drain solution, there are a couple of serious problems that preclude it from being a magic bullet. First, for whatever reason, health departments and inspectors insist on the presence of drains. Exactly when and why that standard became a fixture is unknown, but nonetheless, health codes require drains and short of a sea change in thinking on the subject, it’s likely to stay that way for the foreseeable future.
Second, there are common situations where doing away with bottom drains is difficult or even impossible. Basically any system that doesn’t have the luxury of a skimmer, such as a perimeter overflow pool, or most spas, will need either floor- or side-mounted suction points.
With that in mind, Skip Phillips, owner and founder of Questar Pools (Escondido, Calif.) and co-founder of Genesis 3 Design Group, is working on a new type of drain fixture that is intended to both eliminate entrapment risks and be far less distracting visually, a developmental journey he discusses in the following feature, “Slot Solutions.” It’s a fascinating discussion and one that might point us in the direction of an answer to the entrapment problem.
In my humble opinion, the no-drain option is a great way to go when the opportunity presents itself and we shouldn’t discount it simply because it’s not the answer in every single situation. I’ve personally seen a number of pools that don’t have drains, and they certainly appeared to be functioning just fine, and there’s no question that those pools will never be the site of an entrapment incident.
Of course, the big news in the past year has been the massive recall of drain covers. As described in VGB, all suction covers must comply with ANSI/ASME A112.19.8-2007 standard. Fair enough, drain manufacturers should observe standards for things like flow rates and aperture sizing.
Unfortunately, that seemingly innocuous requirement took on a whole new caste when this past May the CPSC dropped a bombshell announcing that covers made by eight major manufacturers were not in compliance and had to be replaced immediately. Safety advocates heralded the bold move, while others forced to contend with the issue on the ground were left wondering how this could happen, and for a time were left in the lurch without suitable replacement covers.
Obviously, there’s no turning back the clock on this front and fortunately, a number of manufacturers have stepped in and are now producing replacement covers. But at some point it would be useful for someone to release a detailed analysis of the recall with the idea that we might be able to avoid this type of folly in the future. In a broader context, this focus on drain covers raises a potentially even more important point.
Backing up a bit, I’ve long been an ardent admirer of Dr. William N. Rowley, president of Rowley International (Palos Verdes Estates, Calif.) Rowley, a fellow with the American Society of Mechanical Engineers, the same organization that wrote the standard for drain covers, has spent more than three decades studying suction entrapment incidents and often testifying as an expert witness in various lawsuits that typically arise in their wake.
His opinions have at times been controversial and as a result he has been the object of withering personal attacks from those who do not agree with some of his positions. Agree or disagree, there can be no question he is devoted to the cause of working to combat the problem. On more than one occasion he used his own body as a test specimen for human entrapment testing, and he is by all accounts one of the most credible people dealing with the entrapment issue.
According to Rowley and indeed based on everything I’ve ever read on the subject as well, there has never been a suction entrapment accident with a drain cover, any drain cover, that’s properly attached and in place, regardless of its flow rate specs or any other technical characteristic.
Assuming that’s true, how is it that this profound fact has seemingly gone unnoticed?
I’m not saying the ASME/ANSI standards for drains are useless by any means, but if in fact the single common factor in all suction entrapment accidents is a broken or missing cover, why isn’t that the primary focus of entrapment prevention measures? It just doesn’t make sense to let that seemingly significant factor continue to slide by as a footnote.
Frankly, there’s a disconnect there that baffles me.
Most recently, the CPSC further complicated matters voting 3 to 2 in September that so-called unblockable drains on commercial pools with single suction plumbing configurations cannot serve as the sole preventive measure because such drain fixtures can break or become compromised.
Although this new move is frustrating because it adds a layer of complexity to interpreting an already murky set of rules, the fact that it appears to apply to only single-suction configurations is not in of itself a bad thing. The problem comes in knowing that the best second layer of protection should be – SVRS technology, atmospheric breaks, gravity drainage systems or split drains?
Should Be Solved
Fortunately, there are those in the industry for whom common sense is not an obscure characteristic. While I was working with Phillips on his aforementioned “slots” story, he made a comment about this entire issue that really struck a chord. He said that suction entrapment is a problem that should’ve been solved years ago because the knowledge needed to make pools and spas safe has long been established.
He said that issues such as line velocities, split-drain configurations, atmospheric breaks, shut-off switches and overall proper hydraulic design, all of it is settled science and engineering, if not just plain common sense. Yet, because some people in the industry have continued to perform on a substandard level or only work to meet the bare minimum standard, we have in effect allowed this terrible problem to persist.
I couldn’t agree more. It should not have taken, literally, an act of Congress to press the industry toward solving the problem once and for all. As Phillips also pointed out, there is no downside on any level to designing and installing properly engineered efficient hydraulic systems. Not only are they safe, they also save money, make less noise and equipment lasts longer.
To my mind, it’s similar to the reasons why we should all properly inflate our tires. They last longer, perform better, increase gas mileage and are safer. The government shouldn’t have to tell us to do that either.
I’ll wrap this up saying simply that if you really want to make pools and spas safer, then do the right thing and learn how to properly size pumps and plumbing. Use unblockable or split drains, or even no drains at all where possible. Put a shut-off switch near the water’s edge. Use atmospheric breaks and consider using a pump with an on-board SVRS system.
But do it not because the Feds are holding a Sword of Damocles over your head. Instead do it because it’s everyone’s best interest to deliver an end product that doesn’t just meet a minimum standard, but far exceeds it.