Swimming pool sanitation
Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases.
Alongside these two distinct measures within the pool owner's jurisdiction, swimmer hygiene and cleanliness helps reduce organic waste build-up.
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.
[1] 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.
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.
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.
[6] Pathogenic contaminants are of greatest concern in swimming pools as they have been associated with numerous recreational water illnesses (RWIs).
A well-maintained, properly operating pool filtration and re-circulation system is the first barrier, combating the contaminants large enough to be filtered.
To kill pathogens and help prevent recreational water illnesses, pool operators must maintain proper levels of chlorine or another sanitizer.
[10][11] Over time, calcium from municipal water tends to accumulate, developing salt deposits in the swimming pool walls and equipment (filters, pumps), reducing their effectiveness.
[16] Maintaining an effective concentration of disinfectant is critically important in assuring the safety and health of swimming pool and spa users.
However, according to the Hamilton Index, a higher pH can reduce unnecessary chlorine consumption while still remaining effective at preventing algae and bacteria growth.
To help ensure the health of bathers and protect pool equipment, it is essential to perform routine monitoring of water quality factors (or "parameters") on a regular basis.
Both are members of the halogen group with demonstrated ability to destroy and deactivate a wide range of potentially dangerous bacteria and viruses in swimming pools and spas.
Both exhibit three essential elements as ideal first-line-of-defense sanitizers for swimming pools and spas: they are fast-acting and enduring, they are effective algaecides, and they oxidize undesired contaminants.
[17] Chlorinated isocyanurates, a family of organic chlorine-releasing compounds, are stabilized to prevent UV degradation due to the presence of cyanurate as part of their chemical backbone.
Levels of chloramines and other volatile compounds in water can be minimized by reducing contaminants that lead to their formation (e.g., urea, creatinine, amino acids and personal care products) as well as by use of non-chlorine "shock oxidizers" such as potassium peroxymonosulfate.
UV will not replace chlorine but is used to control the level of chloramines, which are responsible for the odor, irritation, and enhanced corrosion at an indoor pool.
Alternative systems also use titanium plates to produce oxygen in the water to help degrade organic compounds.
[19] The rapid sand filter type are periodically 'back washed' as contaminants reduce water flow and increase back pressure.
filters are banned in some states, as they must be emptied out periodically and the contaminated media flushed down the sewer, causing a problem in some districts' sewage systems.
Waste matter is trapped inside one or more sequential skimmer basket sieves, each having a finer mesh to further dilute contaminant size.
Ultimately the sand sieve can be backwashed to remove smaller trapped organic waste which otherwise leaches ammonia and other compounds into the recirculated water.
[25] Alumina, derived from aluminates, filters detrimental materials at the molecular level and can be used to control the delivery rate of desirable metals such as copper.
Prior to the mid 1970s most skimmers were either made of metal like copper or stainless steel either a large round or square shape.
This has the benefit of cleaning the bottom of the pool and slowly moving sunken inorganic debris to the main drain where it is removed by the circulation pump basket sieve.
In a correctly constructed pool, rotation of the water caused by the manner it is returned from the consecutive dilution system will reduce or even waive the need to vacuum the bottom.
With a correctly designed and operated swimming pool, this circulation is visible and after a period of time, reaches even the deep end, inducing a low-velocity vortex above the main drain due to suction.
Correct use of the return jets is the most effective way of removing disinfection by-products caused by deeper decomposing organic waste and drawing it into the consecutive dilution system for immediate disposal.
Features that are part of the water circulation system can extend treatment capacity needs for sizing calculations and can include: artificial streams and waterfalls, in-pool fountains, integrated hot tubs and spas, water slides and sluices, artificial "pebble beaches", submerged seating as bench-ledges or as "stools" at in-pool bars, plunge pools, and shallow children's wading pools.
