Sick or swim? Maintaining a clean, safe, healthy pool.

"While swimming is one of the healthiest activities you can do," explained Dr. Joan Rose, chairperson of the Water Quality & Health Council and a noted microbiologist at Michigan State University, "improperly treated swimming pools can be the source of a variety of infections from waterborne germs." According to Dr. Rose, these pathogens can present themselves in the form of Giardia, E-Coli, Shigella, and Cryptosporidium. "Exposure to these germs can present very uncomfortable results including diarrhea, respiratory illness, ear or nose infections, and skin outbreaks."

It is against this backdrop of concern that a national partnership --between the U.S. Centers for Disease Control and Prevention (CDC), the National Consumers League (NCL), the Water Quality & Health Council (WQ&HC), the Chlorine Chemistry Council (CCC), and the Association of Pool and Spa Professionals (APSP)--has been formed to help inform the swimming public about how to recognize the signs of a healthy pool or spa through a simple check of their senses. The Healthy Pools Campaign hopes to correct certain misconceptions about the public health needs of swimming pools.

According to CDC epidemiologist Dr. Michael Beach, the most recent news on swimming pool health has not been reassuring. At the launch of the Healthy Pools program, Beach cited the most recent CDC research showing that 54 percent of all swimming pools monitored in the study were found to be in violation of at least one public health code. Eight percent of those inspections resulted in immediate pool closures. "It's really a case of basic public health practices relaxing to the point of becoming a problem."

"The groups involved in this partnership came together in order to educate the public about proper water quality control and maintenance," said Jeff Sloan, director of disinfection policy at the CCC. Pool operators in particular have a responsibility toward ensuring the health and safety of their swimming areas. "A healthy pool is not a luxury--it's a necessity," said Linda Golodner, president of the NCL.

Chlorine: The First Line of Defense

Sloan continued, "The CDC has found that inadequate chlorine residual levels are the cause of most pool-related health problems." Chlorine, used in proper levels, is the first defense against germs that can make your swimmers sick; it kills harmful microorganisms responsible for everything from athlete's foot to Legionnaire's disease. That's why it is imperative that pool staff regularly check water quality and maintain proper chlorine and pH levels. For general pool treatment, chlorine has three essential characteristics: it acts as a rapid and persistent sanitizer; it is an effective algaecide; and it is a strong oxidizer of undesired contaminants.

A common mistake swimmers and pool operators make is that by merely detecting a strong smell of chlorine, that means there must be a high level of chlorine present. Ironically, this usually indicates that the opposite is true. "When swimmers notice a pungent chlorine smell, what that really means is that organic chloramine compounds have formed," Sloan said. "The smell indicates that there is too little free chlorine left in the pool."

To rid the water of pathogens, elemental chlorine is generally introduced in the form of a chemical compound, such as solid calcium hypochlorite or liquid sodium hypochlorite. As a byproduct of chlorine's reaction with the water, hypochlorous acid is formed. While the acid is an excellent sanitizer, it has the drawback of not being particularly stable. Ultraviolet light causes the chemical to degrade, which in turn enables it to combine with other chemicals to form new compounds. Chloramines are formed when degraded hypochloric acid combines with body wastes, such as sweat or urine. These organic chloramines are not only poor sanitizers, but also they produce the unpleasant smell and negative side-effects such as eye irritation that are often attributed to some swimming pools.

"Once you have high levels of chloramines, it is then necessary to 'shock' the pool," Sloan said. "This shock chlorination effectively raises the level of free chlorine to a level 10 times that of the chloramines." Shock treatment, or "superchlorination," oxidizes the ammonia and nitrogen compounds to rid the pool of the offensive odor, and leaves behind chlorine residual for continued cleaning. The frequency in which a pool will need to be shocked will vary from pool to pool based on the amount of use.

As chlorine and pH are the first line of defense against waterborne illness, swimming pool operators should constantly by monitoring these two levels in the pool. Chlorine should be ideally maintained between two and four parts per million (ppm), and should never fall below one ppm. The pH level needs to be between 7.2 and 7.8 ppm. (These numbers are broken down into more detail in the table on page 28.) Furthermore, maintaining healthy levels of pool chemicals is a science, and is a process that needs to be supervised by trained professionals. "All pool operators should be certified," Sloan said.

While chemicals can combat a variety of germs, pool operators need to reinforce the preventative measures that will keep pathogens from entering the pool in the first place. Chlorine can kill most viruses within minutes, but there are some germs, like Cryptosporidium, that can live for days--even in a properly disinfected pool. Pool operators need to make clear that all pool users are required to shower before entering pool areas, and swimmers who are ill with diarrhea should refrain from swimming entirely.

The bottom line: maintaining a healthy club pool needs to be made a priority in order to keep members happy and safe. A thorough maintenance program, led by trained professionals, will help clubs realize this goal.

NATIONAL SPA AND POOL INSTITUTE
Suggested Chemical Standards for Swimming Pools

Free chlorine, ppm            1.0-4.0

Combined chlorine, ppm        None
pH                            7.2-7.8
                              (ideal range of 7.4-7.6)

Total alkalinity, ppm         80-100
(for liquid chlorine, cal
hypo, lithium hypo)

(for gas chlorine, dichlor,   100-120
trichlor and bromine
compounds)

Total dissolved solids        Not to exceed 1500
PPM                           greater than at pool
                              start-up

Calcium hardness, ppm         200-400

Cyanuric acid, ppm            30-50