The Physics Behind Waterslides
theodp writes "National Geographic takes a high-level look at the physics behind waterslides. A lot of science goes into providing a safe 60 mph trip down slides like Walt Disney World's 10-story Summit Plummet. 'Safety is our number one concern,' explains Rick Hunter of ProSlide Technology. 'We're thinking about things like, "are you going to stay on the fiberglass tube," it's really easy to do a computer model and look at curves and drops and forecast rider position and speed.'"
Having worked at a water park, I can tell you that they primarily keep the water clean by constantly upping the levels of chlorine and other chemicals. However, it depends on the attraction. Some attractions like slides and flume rides are emptied every night or every week for inspections. A big example is Splash Mountain at the Magic Kingdom. They drain the water every night and pump it out to a treatment facility. New water is pumped in from a retaining pond just outside of the attraction.
Some attractions, such as large wave pools, can't be drained and refilled overnight and instead are typically drained during the off season or during refurbishment only. However, these attractions are constantly having new water added because of evaporation and because some water is drained as it passes through various filters and cleansing agents. An extreme example would be Schlitterbahn, where they siphon part of a river into their park and the water runs through once before exiting back into the river without recirculation. Of course, treatment is done when the water comes in and when the water leaves so it's safe to swim in and safe for the environment.
The most likely source of infection from a waterpark are areas where water does not circulate effectively and thus does not pass through the filters. This is why waterparks have tons of moving water and very little (if any) standing water. Of course, MRSA is also a tough bugger to fight. If you were actually diagnosed with MRSA and your doctor believes you got it while visiting a waterpark, I recommend you contact your state board of health so that it can be taken care of. Waterparks have tons of reporting they need to do, but most of it revolves around chemical levels. Knowing they may have MRSA in the water will result in extra precautions and a more thorough investigation. Blood borne pathogens are not something waterparks take lightly.