Water Clarity Saves Lives
By Terry Arko
It's probably one of the best known "cloudy water" tragedies for anyone in the recreational water realm. On a hot Sunday in June 2011, Marie Joseph went with a group of friends to cool off at the Veterans Vietnam Memorial Pool at Lafayette Park in Fall River, Mass. Two days later, Joseph's body was found floating in the pool. During the outing, Joseph and a 9-year-old were playing on the slide. After sliding down together the 9-year-old surfaced and noticed that Joseph had appeared to sink to the bottom. The 9-year-old notified a lifeguard that Joseph was under water and in trouble. Responses of the lifeguards at the facility are questionable, but one of the undisputed results of the investigation afterwards showed that extremely cloudy pool water hid Joseph from lifeguards, friends and police investigators.
Conclusions reported in The Herald on July 1, 2011, stated that, "low visibility was the reason Marie Joseph's body went unnoticed for two days after she drowned." A police investigation revealed that visibility in the pool was less than 4 feet below the surface. Even though required by state law, the bottom of the pool was not visible at all!
Drowning and near drowning events in cloudy water have been on the increase lately. Many of these tragedies occur at supervised venues with lifeguards and adults in and around the pool. Many times when a person is in trouble or drowning, it isn't noticed at the surface of the water. And the ability to see that someone is beneath the surface can be the difference between life and death. The sooner a victim can be discovered and given CPR, the better their chances of survival.
Cloudy water is a preventable problem. Some of the main causes of a cloudy pool can be poor filtration and circulation, or an influx of particulate matter such as dust and dirt. Also, the build-up of swimmer waste and suntan lotions can cause water to become very cloudy. Water chemistry can play a role as well. If water balance is incorrect such as a high calcium hardness, high pH or total dissolved solids (TDS) can all be a cause of cloudiness. Another cause can simply be too many swimmers and a lack of sufficient sanitizer to keep up with the load. One clear warning for all operators of a commercial recreational pool is that the pool should not be opened if the bottom drain cannot be seen clearly from the pool's deck.
So, what can an operator do to ensure the pool stays clear and the pool patrons are kept safe?
First, always make sure that the pool's equipment is in proper working order. This includes regular inspection and maintenance of filters, pumps and the overall circulation. Concerns about the condition of the pool's filtration system should always be reported immediately to the proper authorities, and reports of any and all work on systems should be kept readily available. In the same manner, all water chemistry balance and sanitizer parameters should be checked throughout the day and recorded and adjusted as needed.
Simply put, clear pool water is accomplished by the efficient removal of tiny micron-sized contaminants that invade swimming pools. These can include such things as dirt and dust, pollen and spores, algae, skin and hair remains from swimmers, and bacteria.
Many of these particles are of a micron size that is smaller than most pool filters are able to capture. As an example, a grain of salt is 100 microns. A good majority of the contaminants in pool water are below 40 micron, which is the limit that the human eye can see. Most recreational facilities use sand filters. Older rapid rate filters can only filter to about 50 microns. The newer high-rate sand filters are capable of removing down to 25 micron. Again, much of the particulate matter in pools is smaller than even 25 micron. Also, this very small material is negatively charged and has a charge to charge repulsion that causes it to bounce around in suspension. The more buildup of this small micron material, the hazier the pool water will become.
A regular oxidation routine of the water helps reduce and breakdown the small micron sized organic contaminants. Regular proactive use of a natural non-petroleum-based clarifier can help prevent a cloudy water situation from occurring. A two-stage double strength clarifier is available and has the ability to take particulate matter down to 0.5 micron and make it removable by the filter. The more small micron particulate matter that is removed by the filter, the better primary sanitizers will work. And the pool water stays clearer for a longer period of time. This is especially critical prior to and after times of heavy swimmer load. In preparation for an unusually heavy swim load, adding an increased dose of clarifier ahead of time can help to pick up the small matter as it is introduced into the pool. At the end of the day, shocking with a non-chlorine oxidizer can help to deal with excess waste and help the pool recover. Clarification and oxidation practiced regularly can also help to reduce the occurrence of irritable chloramines, particularly in inside venues.