title: The application of computational fluid dynamics and small-scale physical models to assess the effects of operational practices on the risk to public health within large indoor swimming pools.
abstract: Swimming pools provide an excellent facility for exercise and leisure but are also prone to contamination from microbial pathogens. The study modelled a 50-m × 20-m swimming pool using both a small-scale physical model and computational fluid dynamics to investigate how water and pathogens move around a pool in order to identify potential risk spots. Our study revealed a number of lessons for pool operators, designers and policy-makers: disinfection reaches the majority of a full-scale pool in approximately 16 minutes operating at the maximum permissible inlet velocity of 0.5 m/s. This suggests that where a pool is designed to have 15 paired inlets it is capable of distributing disinfectant throughout the water body within an acceptable time frame. However, the study also showed that the exchange rate of water is not uniform across the pool tank and that there is potential for areas of the pool tank to retain contaminated water for significant periods of time. 'Dead spots' exist at either end of the pool where pathogens could remain. This is particularly significant if there is a faecal release into the pool by bathers infected with Cryptosporidium parvum, increasing the potential for waterborne disease transmission.
authors.affiliation: Centre for Environmental Strategy, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: Lowell
authors.initials: L
authors.lastname: Lewis
authors.affiliation: Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: John
authors.initials: J
authors.lastname: Chew
authors.affiliation: Formerly Surrey Sports Park Ltd, University of Surrey, Richard Meyjes Rd, Guildford, Surrey GU2 7AD, UK.
authors.forename: Iain
authors.initials: I
authors.lastname: Woodley
authors.affiliation: Department for Environment, Food and Rural Affairs, Nobel House, 17 Smith Square, London SW1P 3JR, UK.
authors.forename: Jeni
authors.initials: J
authors.lastname: Colbourne
authors.affiliation: Robens Centre for Public Health, Department of Civil and Environmental Engineering, University of Surrey, Guildford, Surrey GU2 7XH, UK E-mail: k.pond@surrey.ac.uk.
authors.forename: Katherine
authors.initials: K
authors.lastname: Pond
mesh_terms: D004202:Disinfectants / Q000032:analysis*; D057446:Hydrodynamics; D008962:Models, Theoretical; D011634:Public Health; D018570:Risk Assessment; D013177:Sports; D013551:Swimming Pools; D014871:Water Microbiology; D014872:Water Movements
chemical_list: D004202:Disinfectants