Swimming pool sanitation is the process of ensuring healthy conditions in swimming pools. Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases.
Methods
Two distinct and separate methods are employed in the sanitation of a swimming pool. The filtration system removes organic waste on a daily basis by using the sieve baskets inside the skimmer and circulation pump and the sand unit with a backwash facility for easy removal of organic waste from the water circulation. Disinfection - normally in the form of hypochlorous acid (HClO) - kills infectious microorganisms. Alongside these two distinct measures within the pool owner's jurisdiction, swimmer hygiene and cleanliness helps reduce organic waste build-up.
Guidelines
The World Health Organization has published international guidelines for the safety of swimming pools and similar recreational-water environments, including standards for minimizing microbial and chemical hazards. The United States Centers for Disease Control and Prevention also provides information on pool sanitation and water related illnesses for health professionals and the public. The main organizations providing certifications for pool and spa operators and technicians are the National Swimming Pool Foundation and Association of Pool & Spa Professionals. The certifications are accepted by many state and local health departments.
Contaminants and disease
Swimming pool contaminants are introduced from environmental sources and swimmers. Affecting primarily outdoor swimming pools, environmental contaminants include windblown dirt and debris, incoming water from unsanitary sources, rain containing microscopic algae spores and droppings from birds possibly harboring disease-causing pathogens. Indoor pools are less susceptible to environmental contaminants.
Contaminants introduced by swimmers can dramatically influence the operation of indoor and outdoor swimming pools. Contaminants include micro-organisms from infected swimmers and body oils including sweat, cosmetics, suntan lotion, urine, saliva and fecal matter; for example, it was estimated by researchers that swimming pools contain, on average, 30 to 80 mL of urine for each person that uses the pool. In addition, the interaction between disinfectants and pool water contaminants can produce a mixture of chloramines and other disinfection by-products. The journal Environmental Science & Technology reported that sweat and urine react with chlorine and produce trichloramine and cyanogen chloride, two chemicals dangerous to human health. Nitrosamines are another type of the disinfection by-products that are of concern as a potential health hazard.
Acesulfame potassium is widely used in the human diet and excreted by the kidneys. It has been used by researchers as a marker to estimate the degree to which swimming pools are contaminated by urine. It was estimated that a commercial-size swimming pool of 220,000 gallons would contain about 20 gallons of urine, equivalent to about 2 gallons of urine in a typical residential pool.
Pathogenic contaminants are of greatest concern in swimming pools as they have been associated with numerous recreational water illnesses (RWIs). Public health pathogens can be present in swimming pools as viruses, bacteria, protozoa and fungi. Diarrhea is the most commonly reported illness associated with pathogenic contaminants, while other diseases associated with untreated pools are Cryptosporidiosis and Giardiasis. Other illnesses commonly occurring in poorly maintained swimming pools include otitis externa, commonly called swimmers ear, skin rashes and respiratory infections.
Maintenance and hygiene
Contamination can be minimized by good swimmer hygiene practices such as showering before and after swimming, and not letting children with intestinal disorders swim. Effective treatments are needed to address contaminants in pool water because preventing the introduction of pool contaminants, pathogenic and non-pathogenic, into swimming pools is, in practice, impossible.
A well-maintained, properly operating pool filtration and re-circulation system is the first barrier, combating the contaminants large enough to be filtered. Rapid removal of these filterable contaminants reduces the impact on the disinfection system thereby limiting the formation of chloramines, restricting the formation of disinfection by-products and optimizing sanitation effectiveness. To kill pathogens and help prevent recreational water illnesses, pool operators must maintain proper levels of chlorine or another sanitizer.