Swimming Pool Blog
by John Galcius, May 28, 2009
What can be done at home?
Almost all pools have suction drains on the bottom for circulation reasons. These drains connect to pipes that run directly to the pool circulation pump. Typical flow rate through a residential is anywhere from 40-80 gallons per minute. That’s a lot of suction. If a seal is made on a pool drain, while the pump is running, the suction force is enough to hold a man under water, or pull in hair.
Now that there is a new law, there is no doubt it will prevent loss of life and prevent injury. But the law only applies to commercial and semi commercial pools like hotels and swim clubs. Just because there is no regulation regarding backyard or residential pools yet, that doesn’t mean that homeowners can’t take precautions to prevent entrapment. Replacing your main drain cover is easy and inexpensive. Usually the main drain cover is held on with two screws.
The suction drain grate in swimming pools, spas, and hot tubs can become brittle and crack over time. In addition, the drain cover may be loose or missing. When a person stands or sits on the damaged, loose, or missing drain grate, the suction can hold you to the bottom. And not let go. So, it's easy to make your pool safer, with the installation of a SVRS or a anti entrapment main drain cover.
SVRS stands for Safety Vacuum Release Systems that will disable the pump and or sound an alarm if the flow is blocked. Sensors on the pump detect vacuum and pressure and when thresholds are reached, the pump shuts off immediately to prevent main drain entrapment.
There is talk that the VGB act is being "reformulated" to apply to residential pools as well. Certainly new pools and spas are built only with dual main drains, which helps prevent entrapment. If you have single drains, you can install a VGB approved drain cover that has a design which helps prevent entrapment. Also be mindful of operating your pool or spa with the drain fully open. The suction created can be very strong, and can be fatal.