Public Swimming Pool and Spa Pool Advisory Document Public swimming pool and spa pool advisory document This work is copyright. It may be reproduced in whole or in part for study or training purposes subject to the inclusion of an acknowledgment of the source and no commercial usage or sale. © Health Protection NSW 2013 HEALTH PROTECTION NSW 73 Miller Street NORTH SYDNEY NSW 2060 Tel. (02) 9391 9000 Fax. (02) 9391 9101 TTY. (02) 9391 9900 www.health.nsw.gov.au For more information, please contact your local Public Health Unit whose contact details can be found at www.health.nsw.gov.au This document is intended as a guide and represents a compendium of information on disinfection of public swimming pools. Every reasonable effort has been made to give reliable data and information. No warranty as to the completeness of the information is given. The NSW Ministry of Health and its employees disclaim all liability and responsibility for any direct and indirect loss or damage which may be suffered through reliance on any information contained in or omitted from this document. No person should act solely on the basis of the information contained in this document, without first taking appropriate professional advice about their obligations in specific circumstances. Suggested citation: Health Protection NSW. Public swimming pool and spa pool advisory document. Sydney: 2013. SHPN (EH) 130037 ISBN 978 1 74187 896 7 April 2013 Acknowledgements There were many contributions made in the development of this advisory document. In particular NSW Health would like to acknowledge the Swimming Pool Industry Group, and the organisations below who provided direction and guidance. Aquatic and Recreation Institute Swimming is an Collingridge and Associates Fulham Engineering Services Pty Ltd important recreational Pallintest Australia ProMinent Fluid Controls Pty Ltd activity. Learning to Stevenson and Associates Pty Ltd swim prevents Siemens Water Technologies Trisley’s Hydraulic Services drowning. Swimming Bellingen Shire Council Leichhardt Municipal Council promotes good Ryde City Council Shoalhaven City Council physical, mental and Warringah Council cardiovascular health. Poolwerx Tim Batt Water Solutions Pty Ltd In properly managed pools the benefits of swimming far outweigh any risk. (WHO 2006) Public Swimming Pool and Spa Pool Advisory Document NSW HeAltH PAGe 1 Contents Acknowledgments...........................................4 3.4 Microbiological sampling .................................16 3.4.1 Sampling technique .......................................16 Quick start for pool operators .......................5 3.4.2 Timeliness ......................................................17 A. Chemical criteria ...............................................5 3.4.3 Interpretation .................................................17 B. Chemical testing ...............................................5 3.4.4 Chemical criteria ............................................17 C. Microbiological criteria ......................................5 3.4.5 Database ........................................................17 D. Fact sheets ........................................................5 3.5 Micro-organism risk factors .............................18 E. Pool occupiers information sheet .......................5 Chapter 4: Chapter 1: Disinfection ....................................................19 Introduction .....................................................6 4.1 Overview ..........................................................19 1.1 Overview ...........................................................6 4.2 Disinfectant properties .....................................19 1.2 Purpose .............................................................6 4.3 Disinfection concepts .......................................19 1.3 Scope and application .......................................6 4.4 Characteristics of various disinfectants.............20 1.4 Disease risk from swimming pools .....................7 4.4.1 Chlorine-based disinfectants that produce 1.5 Legislation .........................................................7 hypochlorous acid .........................................20 1.6 A ustralian Pesticides and Veterinary (i) Free available chlorine (free chlorine) .............21 Medicines Authority (APVMA) ...........................8 (ii) The effect of pH on chlorine 1.7 NSW Health website .........................................8 disinfection power ........................................21 (iii) Total chlorine, free chlorine and combined Chapter 2: chlorine .........................................................22 Microbial health risks and transmission ........9 (iv) Bather pollution and the formation of 2.1 Overview ...........................................................9 chloramines ...................................................22 2.2 Micro-organisms ...............................................9 (v) Reducing chloramines ...................................23 2.2.1 Viral pathogens ...............................................9 (vi) Stabilised chlorine – cyanurate 2.2.2 Bacterial pathogens .......................................10 products and cyanuric acid ............................23 2.2.3 Protozoan pathogens .....................................11 (vii) Electrolytic generation of 2.2.4 Fungal pathogens ...........................................12 hypochlorous acid .........................................24 2.3 Disease transmission theory ..............................13 4.4.2 Bromine-based disinfectants .........................24 2.4 Transmission of micro-organisms (i) The hydrolysis of bromine to form hypobromous in swimming pools ...........................................13 acid ...............................................................25 2.5 Conclusions ......................................................13 (ii) The formation of bromamines .......................25 (iii) The effect of pH on bromine Chapter 3: disinfection power ........................................25 Microbiological criteria and sampling .........15 (iv) Isocyanuric acid and bromine ........................26 3.1 Overview ..........................................................15 (v) Breakpoint bromination and 3.2 Indicator micro-organisms ................................15 super-bromination .........................................26 3.3 Microbiological criteria .....................................15 4.4.3 Chlorine dioxide ............................................26 3.3.1 Heterotrophic plate count (HPC) ....................16 4.5 Other disinfection systems ...............................26 3.3.2 Escherichia coli (E. coli) ..................................16 4.6 Disinfection by-products (DPBs) .......................27 3.3.3 Pseudomonas aeruginosa ..............................16 PAGe 2 NSW HeAltH Public Swimming Pool and Spa Pool Advisory Document Chapter 5: 6.4 Water balancing ..............................................40 Disinfection chemical criteria, other 6.4.1 Overview .......................................................40 chemicals, sampling and monitoring ...........28 6.4.2 pH .................................................................40 5.1 Overview .........................................................28 6.4.3 Total alkalinity ...............................................40 5.2 Chemical criteria .............................................28 6.4.4 Calcium hardness ..........................................40 5.2.1 Dosing ..........................................................28 6.4.5 Temperature ...................................................41 5.2.2 Chlorine systems chemical criteria .................28 6.4.6 Langelier saturation index ..............................41 5.2.3 Bromine systems chemical criteria .................28 6.4.7 Corrosive water – The Ryznar index ...............42 5.2.4 Alternate disinfection systems .......................30 6.5 Backwashing of sand filters .............................42 5.2.5 Oxidation-reduction potential .......................30 6.5.1 Reuse of backwash water (externally) ................42 5.2.6 Pool operating periods ..................................30 6.5.2 Recycling of swimming pool 5.3 Other chemicals used in swimming pools ........30 backwash wastewater ...................................43 5.3.1 Chemicals for raising pH ................................30 6.6 Minimising pool pollution ................................43 (i) Soda ash (sodium carbonate Na CO ) ..............30 6.6.1 Restricting bather load and 2 3 (ii) Bicarb (sodium bicarbonate NaHCO encouraging bather hygiene ..........................43 3 – pH buffer) ..................................................30 6.6.2 Total dissolved solids .....................................43 5.3.2 Chemicals for lowering pH ............................31 6.6.3 Water sources ...............................................44 (i) Dry acid (sodium bisulphate NaHSO ) ..............31 (i) Mains water ..................................................44 4 (ii) Hydrochloric acid (muriatic acid HCl) .............31 (ii) Borewater .....................................................44 (iii) Carbon dioxide (CO ) ....................................31 (iii) Rainwater (roof water) harvesting..................44 2 5.3.3 Other chemicals ............................................31 6.7 Prevention and control of chloramines (i) Calcium chloride (CaCl ) ................................31 in indoor aquatic centres .................................45 2 (ii) Potassium monopersulphate (KHSO ) ..............31 6.7.1 Education ......................................................45 4 (iii) Hydrogen peroxide (H O ) .............................31 6.7.2 Superchlorination ..........................................45 2 2 (iv) Ozone (O ) ....................................................31 6.7.3 Shock dosing .................................................45 3 (v) Sodium thiosulphate (Na S2O .5H2O) ...........32 (i) Chlorine dioxide ............................................45 2 3 (vi) Isocyanuric acid (C N O H ) (ii) Potassium monopersulphate .........................45 3 3 3 3 (Cyanuric Acid) ..............................................32 6.7.4 Ultra violet light treatment systems ...............45 (vii) Algaecides.....................................................32 6.7.5 Ozone ...........................................................46 (viii) Flocculants ....................................................32 6.7.6 Granulated activated carbon filters ................46 5.4 Health and safety issues of chemicals ..............33 6.7.7 Zeolite ...........................................................46 5.5 Disinfection by-products .................................33 6.7.8 Ventilation – indoor .......................................46 5.6 Frequency of pool testing ................................33 5.7 Sampling location ...........................................35 Chapter 7: 5.8 Testing equipment and testing ........................35 Design, construction and amenities ............48 5.9 Other chemical and physical parameters ..............36 7.1 Overview and introduction ..............................48 5.10 Record keeping ...............................................36 7.2 Circulation and filtration ..................................48 7.2.1 Surface water removal ...................................48 Chapter 6: 7.2.2 Bather load ...................................................49 Managing water quality ................................37 7.2.3 Circulation rate and pool turnover .................50 6.1 Overview .........................................................37 7.2.4 Water distribution – zonal and non-zonal ...............51 6.2 Chlorine demand ............................................37 7.2.5 Separate plant for high risk pools ...................51 6.3 Chemical dosing control equipment ................37 7.2.6 Dye Testing ....................................................51 6.3.1 Continuous metered disinfectant 7.2.7 Entrapment prevention ...................................51 dosing system ...............................................37 7.2.8 Upgrading existing outdoor pools ..................51 6.3.2 Oxidation-reduction potential .......................38 7.3 Filtration systems ..............................................51 6.3.3 Direct chlorine residual measurement 7.3.1 Element filters (cartridge filters) .....................52 (amperometric) ..............................................39 7.3.2 Granular filters (typically sand filters) ................52 6.3.4 Automatic controllers ....................................40 7.3.3 Ultrafine filters incorporating diatomaceous 6.3.5 pH probes .....................................................40 earth filters ...................................................52 Public Swimming Pool and Spa Pool Advisory Document NSW HeAltH PAGe 3 7.4 M aintenance of swimming pools 10.2.3 Risk management plan ..................................64 and spa pools ..................................................53 10.2.4 Implementation .............................................64 7.5 Change rooms, pool hall and amenities ..............53 10.3 Dynamics of risk analysis .................................64 7.5.1 Floors, walls and change areas ......................53 10.4 Other plans .....................................................66 7.5.2 Light and ventilation ......................................53 10.5 Descriptive risk assessment 7.5.3 Showers ........................................................53 and management of pools and spas ................66 7.5.4 Hand basins ..................................................54 7.5.5 Toilets (water closets) ....................................55 Chapter 11: 7.5.6 Baby nappy change / parent facilities ..............55 Legislation .....................................................67 7.5.7 Waste removal (garbage) ...............................55 11.1 Overview .........................................................67 7.5.8 Storage of hazardous and dangerous 11.2 The Public Health Act 2010 .............................67 chemicals ......................................................55 11.3 The Public Health Regulation 2012 ..................67 7.5.9 Water temperature ........................................55 11.4 Schedule 1 of the Regulation ...........................68 7.5.10 Towel and costume hire ................................55 11.5 Enforcement of the Act and Regulation ...........68 7.5.11 First aid .........................................................55 7.5.12 Shade ............................................................56 Appendix A: 7.5.13 Glass .............................................................56 Breakpoint chlorination 7.5.14 Kiosk .............................................................56 (see section 4.4.1) ..........................................69 1. Combined chlorine and chloramines.....................69 Chapter 8: 2. Continual breakpoint chlorination theory .............70 Cryptosporidium risk management .............57 3. Shock breakpoint chlorination ..............................71 8.1 Overview .........................................................57 8.2 Epidemiology of cryptosporidiosis ....................57 Appendix B: 8.3 Control measures and strategies ......................57 Sample log sheet ..........................................73 8.4 Swimmer hygiene practices .............................58 8.4.1 Personal hygiene ...........................................58 Appendix C: 8.4.2 Awareness of infants who are not Components to consider in recycling toilet trained .................................................58 swimming pool backwash water ..................75 8.5 Education ........................................................59 8.6 Operational control and management .............60 Appendix D: 8.6.1 Barriers used in pool operations ....................60 Components to consider (i) Filters ............................................................61 in water harvesting ........................................77 (ii) Disinfection ...................................................61 8.6.2 Water sampling for Cryptosporidium ..............61 Appendix E: Descriptive risk assessment and Chapter 9: management of pools and spas ...................79 Pool designer and operator competencies ................................................62 Glossary / Abbreviations ..............................81 9.1 Overview .........................................................62 9.2 Pool designers .................................................62 References ....................................................84 9.3 Operator competencies ...................................62 9.4 Formal operator qualifications .........................62 Bibliography ..................................................87 9.5 Pool safety qualifications .................................62 Chapter 10: Health risk management planning ...............63 10.1 Overview .........................................................63 10.2 Public health risk .............................................63 10.2.1 Risk identification ..........................................63 10.2.2 Risk assessment / characterisation .................63 PAGe 4 NSW HeAltH Public Swimming Pool and Spa Pool Advisory Document HEALTH PROTECTION NSW Quick Start for Pool Operators D. Fact sheets The three most important parts of this advisory document for pool operators are: A series of fact sheets which complement this Advisory n Chemical criteria Document can be found at: n Chemical testing http://www.health.nsw.gov.au/environment/publicpools/ n Microbiological criteria and sampling Pages/default.aspx A. Chemical criteria E. Pool occupiers information sheet The mandatory Chemical Criteria is specified in Schedule Information Sheet Number 4 for occupiers of public pools 1 to the Public Health Regulation 2012. Schedule 1 can is provided at: be found at: http://www.health.nsw.gov.au/phact/Documents/is4- http://www.health.nsw.gov.au/environment/publicpools/ public-pools.pdf Documents/public-health-reg-2012-schedule_1.pdf After these essential sections, it is recommended that NSW Health only recommends the use of chlorine or Chapter 1 (Introduction), Chapter 4 (Disinfection), bromine based disinfection systems for public swimming Chapter 6 (Managing water quality) and Chapter 8 pools and spa pools. These systems rely on proper (Cryptosporidium risk management) be studied. concentrations of pH and reserve alkalinity. It is essential Finally, the Contents should be consulted for matters that pool operators also read section 5.2 of Chapter 5. of additional interest. B. Chemical testing The minimum mandatory requirements for chemical testing are also specified in Schedule 1 mentioned above. The frequency of pool testing as best practice is outlined in section 5.6 of Chapter 5. Sampling location is discussed in section 5.7, testing equipment in section 5.8 and record keeping in section 5.10. C. Microbiological criteria The Microbiological criteria are specified in Box 3.1 of Chapter 3. It is important for pool operators to read all of Chapter 3. Public Swimming Pool and Spa Pool Advisory Document NSW HeAltH PAGe 5 CHAPTER 1 Introduction 1.1 Overview Cryptosporidium. Outbreaks of cryptosporidiosis are a problem in public swimming pools because Cryptosporidium This chapter introduces the 2013 Public Swimming Pool is chlorine resistant and is easily transmitted by infants and Spa Pool Advisory Document by explaining its purpose, who are not toilet trained. The advisory document scope and application. This chapter also explains that the highlights minimising the risk of Cryptosporidium disease risk from swimming pools is always present no contamination in public swimming pools and spa pools. matter how well a pool is disinfected and its patrons are managed. There is a brief overview of the public health The advisory document is, where possible, evidence legislation framework to control transmission of disease in based and risk based. The recommended frequency of public swimming pools. A distinction is drawn between chemical and microbiological sampling has been reviewed the role of NSW Health and the Australian Pesticides and to reflect this risk-based approach. This approach means Veterinary Medicines Authority (APVMA) in the approval that high-risk heated pools (particularly spas and of disinfectants which may be used in a swimming pool. hydrotherapy pools) should be tested more frequently At the end of this chapter, advice is available to assist in and low-risk automatically-dosed pools (such as diving navigation of the NSW Health website for pools. pools) less frequently. A chapter is included on risk management of pool operations. 1.2 Purpose Although scientific evidence suggests that the emerging The primary purpose of the advisory document is to issue of disinfection by-products are unlikely to cause provide information and guidance to pool operators, health risks in properly managed pools, some mention is authorised officers (also known as environmental health made of them. Included in emerging issues are those of officers), pool consultants and other swimming pool recycling backwash water and rainwater harvesting. industry stakeholders on the appropriate modern standards to design, operate and maintain healthy The advisory document provides comprehensive swimming pools and spa pools. information sufficient to fulfil an identified industry need for informing operators of pools who may not have The secondary purpose is to complement public health had the opportunity of formal education in swimming legislation, particularly the prescribed operating pool matters. requirements in Schedule 1 to the Public Health Regulation 2012. 1.3 Scope and application Disinfection is critical to prevent the survival and growth This advisory document has a wide informative scope and of micro-organisms in swimming pools and spa pools. some information is provided on the derivation of The quality of incoming water supply, efficient filtration, disinfection concentrations. For example, information is well designed circulation and distribution systems, and an provided on the effect of pH on chlorine disinfection and optimum turnover rate to deliver clean clear water are the derivation of free chlorine and pH values. equally important. Client hygiene management is also an important aspect of disease minimisation. Disease The advisory document is more relevant to those minimisation and water quality are the core themes of swimming pool and spa pool operators to whom the the advisory document. public health legislation applies. Such pools are referred to as public pools. From 1 March 2013, occupiers of The most commonly known micro-organism capable of premises containing public swimming pools or spa pools causing large outbreaks in public swimming pools is must notify their local council of the pool’s existence and PAGe 6 NSW HeAltH Public Swimming Pool and Spa Pool Advisory Document comply with the “prescribed operating requirements”. the pool water in which they are introduced, otherwise a The prescribed operating requirements are set out in disease may be transmitted. The swimming pool or spa Schedule 1 of the Public Health Regulation. pool needs to be designed and operated to enhance the http://www.health.nsw.gov.au/environment/publicpools/ action of the disinfectant. Documents/public-health-reg-2012-schedule_1.pdf All public swimming pools and spa pools must be equipped It is an offence not to comply with the prescribed with effective water circulation, filtration, disinfectant, operating requirements and an authorised officer may issue and pH control systems. Ideally, the disinfection system an improvement notice for failure to comply. In serious and pH systems should be automatically controlled. cases, a failure to comply with the prescribed operating Routine hand, drip or slug dosing of any chemical directly requirements may lead to a prohibition order or closure into an occupied swimming pool or spa pool from a order being issued, closing down the pool. The advisory container is not acceptable and is dangerous. Similarly, document, therefore, provides an understanding of what floating block dispensers are not considered appropriate. constitutes the prescribed operating requirements and explains chemical parameter values for disinfectants and 1.5 Legislation pH levels for various circumstances. The Public Health Act, 2010, was commenced on An emerging type of swimming pool is the multi-residential 1 September 2012. Sections 34 to 37 apply to public pool such as those associated with apartments or town swimming pools and spa pools. Section 35 however house developments. While such pools are not public commences on 1 March 2013. Under the Act, a public swimming pools under the Public Health Act, they can swimming pool means a swimming pool or spa pool to still pose risks in terms of bather risk. The advisory which the public is admitted, whether free of charge, on document is equally applicable to this situation, but in payment of a fee or otherwise, including those swimming a non-regulatory and advisory sense. pools and spa pools: Authorised Officers (or Environmental Health Officers) n To which the public is admitted as membership of should use the document to assist in developing skills in a club, determining pool water quality, to determine when there n Provided at a workplace for the use of employees, may be a risk to public health and therefore to determine n Provided at a hotel, motel or guest house or at holiday the nature of any enforcement action, if necessary. units, or a similar facility, for the use of guests, and n Provided at a school or hospital, 1.4 Disease risk from swimming pools but not including a pool situated on private residential premises. Disease transmission, even in the best operated pool is always possible. At best, the time taken to transmit a The Public Health Act and Public Health Regulation set disease can only be minimised to a fraction of a minute out specific requirements for occupiers of premises because it takes time for a disinfectant to kill or inactivate containing public swimming pools and spa pools and micro-organisms. There is no instantaneous kill of micro- there are offences for non compliance. In particular: organisms and swimming pools cannot be made sterile. The advisory document provides information about n An occupier must give notice of the pool’s existence conditions under which a fast kill of disease-causing to their local council (this requirement commenced on micro-organisms can realistically be achieved. 1 March 2013) n An occupier must comply with the prescribed Public pools are more likely to be contaminated with a operating requirements, which are set out in Schedule greater diversity of disease causing micro-organisms than 1 of the Public Health Regulation (this requirement single domestic swimming pools. This is because public commences on 1 March 2013) pools are used by unrelated people and are more likely to n The occupier must not allow a person to use the pool have higher bather loads. Pathogenic (disease causing) unless the water is disinfected in such a way as to micro-organisms must be quickly and effectively killed in minimise the transmission of disease to users of the pool Public Swimming Pool and Spa Pool Advisory Document NSW HeAltH PAGe 7 n The occupier must ensure that the pool surrounds, 1.6 Australian Pesticides and including any toilets and change rooms, are kept Veterinary Medicines Authority clean and in such condition as to minimise the (APVMA) transmission of disease. Before swimming pool disinfection products can be sold, Authorised Officers of both NSW Health and local supplied, distributed or used in Australia, they must be councils are empowered to inspect public pools. As well registered by the APVMA, a Commonwealth agency as being an offence, a failure to comply with prescribed based in Canberra. The registration process is governed operating requirements could lead to an improvement by Commonwealth legislation and undertaken according notice directing compliance. If there is a breach of a to accepted scientific principles and through rigorous prescribed operating requirement and the pool poses a independent analysis by several government agencies and serious risk to public health, a prohibition order may be the APVMA. A list of approved sanitisers is provided on served on the occupier to close public swimming pools the APVMA website at: and spa pools to prevent or mitigate a serious risk to http://www.apvma.gov.au/. public health. There is also power under the Public Health Regulation to close down a public pool or order public The use of APVMA unapproved packaged disinfectants in health action to be taken in relation to a pool that poses any public swimming pool or spa pool is not supported a risk to the public even if the prescribed operating by NSW Health. Additionally, the only future disinfectants requirements are being met. that will be recognised as primary disinfectants by NSW Health will be those which have been independently The prescribed operating requirements for public pools tested against the “APVMA Guide for Demonstrating can be found at Schedule 1 of the Regulation. Efficacy of Pool and Spa Sanitisers”. This document can http://www.health.nsw.gov.au/environment/publicpools/ be accessed on the APVMA website above or on the Documents/public-health-reg-2012-schedule_1.pdf NSW Health website below. The prescribed operating requirements require that pools may only be disinfected with chlorine or bromine using 1.7 NSW Health website automated or continuously metered dosing systems. Dosing systems are discussed in Section 6 of this The URL for the NSW Health is: document. Disinfectant, temperature, pH, alkalinity, http://www.health.nsw.gov.au/ ozone and cyanuric acid parameters, testing requirements are also specified in Schedule 1. To navigate to the Swimming Pools and Spa Pools page click on “A to Z” on the blue banner and then click on The former “Guidelines for Disinfecting Public Swimming “S” and finally click on “Swimming pools and spas”. pools and Spa Pools – June 1996” have been withdrawn as they are no longer valid. NSW Health is not an approval authority. It does not have the power to approve of chemicals, disinfectants, pool design or pool operational activities. NSW Health does not have the capacity to become involved in pool design or operation. The legal function of NSW Health and local councils is to monitor and determine public health risk and act accordingly to require the abatement of the public health risk in public pools. PAGe 8 NSW HeAltH Public Swimming Pool and Spa Pool Advisory Document