2015 Anti-Entrapment Fall Forum Lifesaving Society Alberta and the Northwest Territories William N. Rowley PhD, PE, D-IBFES, D-NAFE
Beginning • State-registered professional engineer designing swimming pools, spas, equipment, etc. with emphasis on public safety • 23 patents, 8 of which are Canadian • Was contacted by County of Los Angeles Chief Sanitarian Ernie Kraul in May 1974 to investigate a suction entrapment drowning in a residential spa in Santa Ana, California.
Testing • First S.E. testing and reporting in 1974 • 1977 CPSC Suction Entrapment Tests • 1997 Dual Main Drain S.E. Tests • 2002 Dual Main Drain and Atmospheric Vent Line Testing • 2007 Dual Main Drain S.E. Tests • The only human-subject testing for S.E. until 2002 • Human subject was Rowley
Raising Awareness • Published 6 articles between 1974 and 1977 • 1974 Brought S.E. to attention of the CPSC, NSPF, and the NSPI • Briefed CPSC in 1977 and 1996 • 1997 Aquatics International article • 1997 California Senate Bill 873 • 1997 NSPF Report • 2002 California Senate Bill 1726 • 2006 NSPF Aquatic Safety Compendium • 2008 Int’l Journal of Aquatic Research & Edu .
Litigation • Suction entrapment litigation started in late 1970s • Landmark cases: • 1993 Wake County, NC • 2000 Dade County, FL • 2003 Playa Del Carmen, Mexico • 2007 Cartagena, Colombia • 2007 Fairfield County, CT Familiar with but not involved in 2002 VGB Case •
Playa Del Carmen, Mexico
Playa Del Carmen, Mexico
Cartagena, Colombia
Suction Entrapment can occur in • Wading Pools • Spa Pools • Swimming Pools • Anything that has a single source of suction
Suction Entrapment • Physical Description • Technical Description • Recommendations
Suction Entrapment • Body Entrapment
Suction Entrapment to pump (main drain grate missing or broken) Body Entrapment
Suction Entrapment • Body Entrapment • Limb Entrapment
Suction Entrapment to pump (main drain grate missing or broken) Limb Entrapment
Suction Entrapment • Body Entrapment • Limb Entrapment • Disembowelment–Evisceration
Suction Entrapment (main drain grate missing or broken) to pump Disembowelment–Evisceration
Suction Entrapment • Body Entrapment • Limb Entrapment • Disembowelment–Evisceration • Hair Entrapment–Entanglement
Hair Entrapment / Entanglement
Engineering Standard Hazard = Risk x Exposure If there is a hazard: 1. Remove it 2. Guard against it 3. Warn about it
Remove the Hazard
Dual Suction–Main Drain and Skimmer skimmer waterline pump main drain
Properly Installed Multiple Main Drains main drain main drain to pump
Improperly Installed Multiple Main Drains main drain main drain to pump
Spa with Wall Mounted Main Drains waterline main drain main drain to pump
8” Round Main Drain Outlet screw (typical 2 places) to pump • grate must be attached so that it cannot be removed except with use of tools • grate must be ASME / ANSI / VGB listed
8” Round Main Drain Outlet Force in Pounds vs. Vacuum in Inches of Mercury 30 8" Round 25 Vacuum– 20 Inches of 15 Mercury 10 5 0 0 125 250 375 500 625 750 Force in Pounds
Swimming Pool Main Drain Outlet Force (Pounds) vs. Open Area in Inches 2 @ 15” (7.35 PSI) and 27” (13.23 PSI) of Mercury Vacuum 180 15" Hg. Vac 160 12” square 140 27" Hg. Vac 120 in 2 100 80 60 8” round 40 20 0 0 250 500 750 1000 1250 1500 1750 2000 Force in Pounds
Recommendations • Connect all suction piping to at least 2 suction outlets with VGB-compliant covers • Keep water velocity in all suction piping under 6 fps main drain main drain to pump
Suction Entrapment Prevention Enacted in Law 1. California Senate Bill 873 – 1997 2. California Senate Bill 1726 – 2002 3. (U.S.A.) Federal Virginia Graeme Baker Pool and Spa Safety Act – 2007 (also known as the VGB Act, became effective December 20, 2008)
Before the (US) VGB Act The CPSC tracked suction entrapment incidents for the years 1983-2002. In this time period, there was an average for pools and spas of: ~8 total incidents per year, of which ~2 fatal incidents per year
After the (US) VGB Act The CPSC tracked suction entrapment incidents for the years 2009-2012. In this time period, there was an average for pools and spas of: ~5.5 total incidents per year, ~0 fatal incidents per year. ~30% decrease in incidents 100% decrease in fatalities
Alternatives? • Safety Vacuum Release Systems (SVRS) • Automatic Pump Shut-Off Systems Issues: • They do not prevent suction entrapment incidents. They respond after one occurs. • They are only designed to respond to body entrapments. • They will not stop limb entrapments, hair entanglements, or eviscerations.
Alternatives? • Suction-Limiting Vent System Issues: Will stop body entrapment • and evisceration. Will not stop limb • entrapment. Questionable whether it will • stop hair entanglement. Most expensive option if • pool is already built.
Thank you.
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