The commercial pool and spa industry was rocked recently by the Consumer Product Safety Commission’s mandatory recall of main-drain grates — devices that had been designed, engineered and manufactured within the past two years to meet specific provisions of the Virginia Graeme Baker Pool & Spa Safety (VGB) Act.
Issued as a result of independent tests conducted using a protocol developed by the American Society of Mechanical Engineers, the recall applies to the drain grates of eight key suppliers. It refers only to grates installed on commercial pools with single-suction main drain configurations — that is, on systems that do not have what are defined as “unblockable” drains, meaning either split main drains or drains with openings that exceed minimum dimensional standards.
CPSC’s move threatens to close innumerable commercial pools and spas, with safety advocates heralding a great victory for suction-entrapment prevention and others questioning both the foundation and efficacy of the recall.
How is it that all eight of these manufacturers went so terribly off track? Without going into excruciating detail, the ASME-prescribed test calls for placing an 18-by-23-inch panel rigged with a rubber lining (to simulate the pliability of a human body) over drain covers, backed by 120 pounds of pressure. Once the system is initiated and the panel is moved onto the drain cover, the test involves trying to pull the panel straight off the drain.
Supposing the test protocol to be defensible (which I don’t think it is), I see a larger question here that is being overlooked: Why, after all these years of examining this issue up one side and down the other, do single-suction drains still exist?
Part of the answer, I’m certain, has to do with conventional practice and long habit on the part of those who’ve designed, engineered and built these pools. But another part, I think, has to do with the fact that the VGB Act describes specific measures — that is, secured drain covers, atmospheric breaks and SVRS systems — as making it “safe” to stay with single-suction main drains.
My issue with these measures — all of which I would classify as mitigating steps rather than as true solutions — is this: Although they are admirably intended to minimize the risks associated with single-suction drains, they are themselves subject to failure. Atmospheric breaks can be blocked or improperly installed; drain grates break; SVRS systems can fail; and even dual main drains can be blocked on one side, in effect creating single-suction scenarios.
Yes, regular maintenance and vigilant management can help in avoiding these problems, but we all know that lapses occur in the real world of pool operation.
All of this explains why I look at this issue in a different way. When confronted with a hazard, any engineer worth his salt will tell you that the best and most preferred way to deal with that hazard is to eliminate it altogether. And that means adopting a position we’ve advanced many times in the pages of WaterShapes: Design and retrofit pools — commercial and residential — with no main drains at all.
There are, of course, obstacles to this concept, the primary one being the fact that most health departments have yet to accept the no-drain solution. Until that situation changes, it leaves engineers and builders with the second-best option, which is figuring out how to come up with a VGB-compliant solution using main drains, grates and manufactured anti-entrapment systems.
Personally, I can’t take issue with commercial pools with single-suction systems being shut down: I think it’s a plumbing approach that should have been abandoned decades ago. But we face a situation in which the second-best solution — unfortunately, the only allowable remedy in most jurisdictions — does little or nothing to address the fact that single-suction main drains will always be hazardous, no matter how we might dress them up.
If you want a real solution, then just get rid of them! After all, there’s no disputing the fact that you cannot become stuck on, entangled in or eviscerated by a suction point that does not exist.
I truly can’t understand resistance to this idea. If you can explain it to me, please do so below.