Aquatic Suction Outlet Injuries

Aquatic Suction Outlet Injuries


There are three different types of incidents where victims become “entrapped” on a pool or spa suction outlet. (A suction outlet is similar to a drain – it is where the water leaves the pool to go to the pump.) The three types of incidents are:

– Suction entrapment
– Mechanical (finger) entrapment
– Hair entanglement

Suction entrapment occurs when a person’s limb or torso is trapped on a suction outlet. This can either be limb entrapment, body entrapment, or evisceration. Limb entrapment occurs when a person’s foot or arm becomes stuck in a suction outlet. Suction entrapment incidents typically occur in shallow pools, wading pools and spas when part of a victim’s body blocks an open source of the suction outlet. When the pump connected to the suction outlet is turned off, the trapped person can be removed from the suction outlet. Almost always when suction entrapment occurs, a single suction outlet is the only source of flow to the pump, and the drain cover is broken or missing.

Mechanical entrapment occurs when a person inserts a finger into a hole (in pools and spas, this would typically be in a drain cover on a suction outlet) and it becomes stuck. This type of incident is not caused by suction –the digit is trapped by friction, not suction. This phenomenon is demonstrated by Chinese finger puzzles. Turning off the pump connected to the suction outlet does not affect removal of the trapped digit from the drain cover.

Hair entanglement occurs when a person’s hair becomes entangled in a drain cover over a suction outlet, which entraps the person’s head on the drain cover. The hair entanglement is not caused by suction – it is caused by turbulent water velocity. Turning off the pump connected to the suction outlet does not untangle the person’s hair from the drain cover.

Each year there are a handful of these types of aquatic entrapment incidents in commercial pools and spas as well as private pools and spas. Both Dr. Rowley and Mr. Reynolds are passionately committed to eliminating all three of these types of incidents. Dr. Rowley is a pioneer researcher and expert on the subject and has been retained in more than 50 suction entrapment cases.

suction examples

Dr. Rowley’s efforts have resulted in standards and technical developments that measurably contributed to the goal of reducing all types of aquatic entrapment. Additionally, he has conducted numerous speaking engagements including industry conferences and presentations to health agencies on the topic of Suction Entrapment. Rowley authored Chapter 7, “Suction Entrapment,” in the National Swimming Pool Foundation’s Aquatic Safety Compendium, 2006. He wrote a peer reviewed report, “Dual Main Drain Suction Entrapment Test Report” in the International Journal of Aquatic Research and Education, 2008. Dr. Rowley presented “Anti-Entrapment” at the Lifesaving Society of Alberta & North Western Territories in Alberta, Canada, 2015. Both Rowley and Reynolds presented “Hair Entanglement” at Society of Forensic Engineers & Scientists in Berkeley, CA, 2018.