What is the Code of Practice?
The PWTAG Code of Practice provides pool operators with a structured plan for the technical operation of their pool. The code ensures that the technical operation of a pool meets quality standards that provide a healthy experience for swimmers using recognised and established practices, techniques, engineering and design. For this reason all UK pools are encouraged to follow it.
The Code provides a model of operation based on the authority of PWTAG good practice. Following the Code gives an assurance to operators and to the public that the pool meets essential healthy pool operational standards.
The Code is designed, among other things to meet the health challenge of one of the greatest threats that the sector has to deal with - the chlorine-resistant pathogen. Cryptosporidium. The code is based on the 2009 PWTAG book, Swimming Pool Water: treatment and quality standards for pools and spas. It does not replace the book. Operators should still refer to it, and it provides some of the basics for PWTAG's training material. Pools that follow the Code ofPractice can put themselves forward to be assessed against it.
Pools that meet the standard of the Code can be recognised by accreditation with the PWTAG Poolmark award.
This CoP contains general operational and safety recommendations for the management of swimming pool water treatment systems and associated water treatment plant, heating and ventilation systems. The CoP sets out how the technical operation of the pool should function for a safe and successful swimming pool water.
Updated to reflect the requirements of Managing Health and Safety in Swimming Pools (HSG179)
1.1) Why a code of practice?
The purpose of this CoP is to provide pool managers and operators with the fundamental principles of good practice in swimming pool water technical operation. Following it, pool staff should be able to provide a safe, enjoyable swimming experience for users as well as a safe operation for workers.
1.2) The main risk in swimming pool water treatment are health issues
1.3) Potential risk to the individual
1.4) Potential risk to your organisation
1.5) Good practice
This CoP focuses on good practice, based principally on published guidance from PWTAG, guidance to the industry from PWTAG that has been developed over many years. It also includes material from the Health and Safety Executive, Public Health England, Public Health Wales, Health Protection Scotland, the World Health Organisation and BS EN standards.
1.6) Standards of design and equipment
This CoP assumes that a pool is designed in accordance with the guidelines detailed in Swimming Pool Water. Where pools have inappropriate design or inadequate specification, then providing a safe, quality swimming pool water will present a challenge which ideally should be addressed prior to defining operational practices.
1.7) Types of pool covered by the code of practice:
This CoP covers swimming pools as defined in British and European standards:
1.4.1 Swimming pool type 1 – pools where the water-related activities are the main business (e.g. communal pools, leisure pools, water parks, aqua parks) and whose use is public
1.4.2 Swimming pool type 2 – pools which are additional services to the main business (e.g. school, hotel, camping, club, therapeutic) and whose use is public.
1.8) Types of pool not covered by the code of practice:
However, many of the principles contained within the CoP can also be successfully applied in these types of premises. And they are specifically dealt with in Swimming Pool Water.
The pool operator has a general duty to set out a safety policy for the operation of the pool in its environment.
2.1) PSOP - Pool safety operational procedures
The recognised way to define a pool’s safety policy is to establish and maintain pool safety operational procedures (PSOP). There should be two sections – normal operational plans (NOP) and emergency action plans (EAP). The PSOP should include management’s assessment of hazards associated with all aspects of the pool – physical, risk of infections and supervisory – as well as a section on the technical operation of the pool which features swimming pool water quality.
2.2) Pool technical operation procedures (PTOP)
This CoP requires pool management to define and document its policy and procedures for the general operation of the pool water treatment. This is called the pool technical operation procedures (PTOP). The PTOP forms a part of the risk assessment process for the whole pool facility and the subsequent formulation of pool safety operational procedures (PSOP). It should take the form of a stand-alone document detailing a swimming pool’s technical operation which is part of the PSOP.
The pool PTOP will be based on PWTAG published guidance, but more particularly the requirements of the suppliers, manufacturers and installers of plant and equipment. It will set out how the plant should function and be operated safely. Just as significantly, the PTOP for a pool will incorporate operational considerations that provide a healthy, enjoyable, satisfying and safe experience for users. The PTOP may use this CoP for its structure, supplemented or amended where appropriate to the individual circumstances of a pool.
2.3) Planning and organising
Preparing a PTOP demands planning the approach to pool water, ensuring that it integrates with other management activities.
2.4) Elements of an organisation’s PTOP
Whatever the size of organisation and resources available, the first step is to establish a policy for water quality, safety, and hygiene and to have a strategy for its implementation. There should be clear objectives and a good management plan to achieve them. Learning from experience is important. You should review the outcomes and, if necessary, make changes to improve things.
Preparing a PTOP is no different to other management processes that demand a systematic approach, as shown in the diagram below.
2.5) Policy and planning
Developing a policy for water quality management and promoting a plan for its achievement will ensure effective use of the organisations' resources as well as ensuring bather safety. An effective policy will:
An effective strategy will:
2.6) Planning and organising
Develop plans for the management of the quality and safety of pool water at levels appropriate to the size and structure of the organisation. A large enterprise attracting hundreds of thousands of bathers each year would need a detailed PTOP. For a small pool, open on a limited basis, a much more basic document covering essentials would be sufficient. This code of practice contains the information necessary for producing such a document.
2.7) Implementation and operation
The key to implementation and operation is defining clear roles and maintaining the awareness of those involved.
Define clear roles - State who is responsible for carrying out each task identified in the PTOP.
Awareness - Pool management should establish and maintain procedures in the PTOP to make staff and others involved aware of the importance of their roles and responsibilities in complying with the pool procedures, and with the requirements of the PTOP.
Performance monitoring - There should be a programme of inspection and clear records kept of the findings and actions. It helps to follow a written programme of priorities, keeping a record of what has been done, when, where and by whom, then listing work planned for the future. Management will then be able to demonstrate progress and ensure that the investigation and resolution of any outstanding issues is included in a work programme.
Learn from incidents and near misses - Incident and accident data are valuable indicators of risk and provide a measure of performance. Near misses should not be ignored; rather, staff should be encouraged to report them and treat them as an opportunity to learn from something that did not quite happen, this time.
2.8) Monitoring, analysis and improvement
As a minimum, pool management should monitor the safe and effective performance of their pool operation through the following:
2.9) Learning and improvement
Management should learn from the information gathered, in order to make improvements. Routine work should incorporate mechanisms that allow feedback to be used to improve services and safety, and to explain why no changes are being made.
2.10) Review against the written PTOP
Review is a key part of a management process. Decisions made as part of the monitoring, learning and improving processes should be checked at each stage to ensure they are consistent with guiding principles. Progress should be measured against plans, to identify problems and instigate any necessary corrective actions.
The water treatment system and the pool hall ventilation and heating should both be formally reviewed at planned intervals (at least annually) to ensure their continuing suitability and effectiveness. Ideally, this should be prior to or during annual maintenance.
Input to the review should include assessing opportunities for improvement and the need for changes to the water treatment system, including the policy. Inputs to the management reviews should include:
2.11) What pools – what staff?
All pools should have some form of staffed presence responsible for their technical operation and supervision. The type of cover depends on the type and use of pool. Both swimming pools types 1 and 2 (see 1.8) will need a swimming pool technical operator (SPTO) if they:
2.12) Swimming Pool Technical Operator (SPTO) –
These are qualified, trained and competent technical operators, available on-site/on call during all hours of operation:
Onsite designated supervisor, visiting technical operator
All pools that do not require an SPTO as defined above should instead have a staffed presence of an onsite designated supervisor with a visiting technical operator.
The onsite designated supervisor should be capable of testing the water quality as required by this CoP and know how to make adjustments as needed to maintain water quality. Although not responsible for plant maintenance, they must be knowledgeable and competent on the operation of the facility in terms as required in the pool’s PSOP for both normal and emergency action plans
The visiting technical operator should provide regular [RC] (weekly minimum) visits and assistance whenever needed. Written documentation of these visits should be available at the facility. The written reports should at least show that:
2.13) Training and competence
Only trained, competent people should operate plant and handle chemicals. In meeting this requirement, the training for the safe operation and use of equipment and chemicals will need to:
2.14) Monitoring and recording of training
Pool management will need to check that trained technical staff understand and follow all procedures and responsibilities included in the PTOP. Monitoring and review of the effectiveness of arrangements should then follow. Details of qualifications and actual training sessions will need to be recorded and reviewed. Information, instruction, and training are the essential requirements for all staff involved in the operation of technical plant and the storage, handling and use of pool chemicals.
In meeting these requirements, training will need to include sufficient knowledge and understanding for staff to be alert to any changes affecting the operation of the system and likely to affect general safety. This should include changes to the pool plant equipment, chemicals or practices.
2.15) Technical operator qualifications and certificate
2.16) PTOP: system documentation (an example of a PTOP is given in Annex 17)
The PTOP should be maintained in paper or electronic form and should contain or refer to the following:
The pool management must ensure the effective implementation of all documented procedures and instructions and these must be recorded. Records should be maintained to chronicle the technical operation of the pool and plant.
It is important that records demonstrate that:
Records should be kept so that continued confidence may be demonstrated for a period of at least five years.
The effective technical operation and safety in any swimming pool starts with careful planning, specification and design. The specific sources of information from which the technical design and planning standards recommended for swimming pools can be obtained are:
Everyone involved in the process of specifying, designing and constructing pools should be familiar with these design standards and should ensure that they are given careful consideration in all pool projects.
Water treatment systems are an integral part of the architectural, structural and mechanical design of a swimming pool. The design, selection and operation of water treatment plant has to take into account:
3.1) Public health hazards
Within a pool facility there are many potential uses of water where users and those in the vicinity may be exposed to hazards with the potential to cause injury and waterborne illness. Examples include:
3.2) Mains water quality
The water companies’ treatment processes provide safe water but, especially if from a river or reservoir (surface waters), are likely to contain some or all of:
So it is essential that there is careful control of a pool’s disinfection, pH, alkalinity, calcium hardness, dissolved solids and filtration.
3.3) Source water monitoring
Pool plant treatment should be set up to take account of an analysis of all relevant source water parameters. The water should meet drinking water quality standards; this applies also to private water supplies. The disinfectant type should so far as practicable be compatible with the source water supply.
3.4) Pool water clarity
Clarity of pool water is critical. It should be possible to see clearly the detail of the bottom of the pool at its deepest point from the pool surround. If not, this is a sign of deterioration in water quality and could lead to an immediate physical danger to anyone in distress, as well as the likelihood of discomfort to bathers because of the poor condition of the water. Also, it is a sign of ineffective disinfection and similarly if the cause of the cloudy water is ineffective filtration then disinfection will be compromised.
Clarity is reduced by turbidity – colloidal or particulate matter in suspension in the water. It is important to know the source of turbidity – whether pollution from bathers, external contamination, inadequate circulation/turnover or disinfection, or incorrect use of water treatment chemicals – in case this can be dealt with directly. The likeliest remedy, however, is adequate filtration and appropriate disinfection.
Turbidity in a swimming pool is measured in nephlometric turbidity units (NTU). The value generally used to measure turbidity in swimming pool water is 0.5NTU. Drinking water should have a value not exceeding 1.0NTU and the World Health Organisation (WHO, 2004) state that for effective disinfection to take place, the turbidity levels in the water to be disinfected must be <1.0NTU. High levels of turbidity can protect microorganisms from the effects of disinfection.
3.6) Primary disinfection
Disinfection means removing the risk of infection, and is achieved primarily by maintaining the correct concentration of disinfectant in the water. Primary disinfection will kill bacteria and viruses (and provide a residual to prevent cross-contamination); oxidation by disinfectants also breaks down soluble dirt and other organic contamination introduced by bathers.
At the same time other water quality parameters, in particular pH value, have to be kept at the correct value for disinfectant to act effectively and efficiently.
For disinfection to proceed freely, the water must be clear and free of suspended material which may shelter the microorganisms from disinfectant activity. Effective filtration is key to this. Equally, the disinfectant has to be given time to kill.
Many disinfectants also oxidize waste matter, controlling the build-up of what is the food for many microorganisms (as well as a water contaminant in its own right) and helping maintain a fine sparkling water Mains water contains a small amount of such material, but the chief sources are introduced by bathers – sweat, skin particles, mucus and urine. Such bather pollution can and should be minimised by pre-swim hygiene (see 7.2).
Dosing disinfectant before the filter prevents inadvertent mixing of disinfectants and acids (which are added post-filter). However there are arguments for dosing disinfectant post-filter; (this issue is dealt with in Swimming Pool Water). Secondary disinfection by ultraviolet (UV) radiation or ozone (which remove or reduce primary disinfectants), demands dosing disinfectant after the secondary treatment.
Automatic dosing (disinfectant and pH value kept to set limits in response to continual monitoring) is the preferred and usual method of applying disinfectant to the water.
3.7) Secondary disinfection
Secondary disinfection of pool water (UV or ozone) increases the kill of infectious organisms, especially the chlorine-resistant protozoan Cryptosporidium. Due to the risk of cryptosporidiosis it is recommended that swimming pools include secondary disinfection systems to minimise the risk to bathers associated with such outbreaks. This is particularly important with pools used by young children. There are other benefits in water quality, including the reduction of troublesome, irritant chloramines and being able to have lower disinfectant residuals in the pool water. These systems will take the form of either UV or ozone and should be designed to provide an effect equivalent to achieving a 99% reduction in the number of infective Cryptosporidium oocysts per pass through the secondary disinfection system.
UV should be applied to the full flow of water through the treatment plant and monitored to ensure an effective dose rate. UV systems intended for the control of chloramines as well as microorganisms should be equipped with medium-pressure lamps at 60mj/cm2 (broad spectrum between 200 and 320nm).
Low-pressure lamps (254nm) are only biocidal, so they will deal with bacteria and Cryptosporidium but do not deal with di and tri-chloramines as effectively as medium-pressure UV.
The system should be designed to achieve a minimum 99% reduction in the number of infective Cryptosporidium parvum oocysts per pass through the UV system. UV systems should be third-party validated (see PWTAG Technical note 31).
Ozone should also be applied to the full flow of water through the treatment plant, with separate contact and deozonising systems. Contact time should be at least two minutes, and the ozone concentration 1mg/l in water circulated.
3.8) Dilution with fresh water
Disinfection and filtration will not remove all pollutants. UV and ozone will greatly improve removal but some pollution can be reduced only by dilution of the pool water with fresh potable water. This should also limit the build-up of pollutants from bathers and elsewhere, the byproducts of disinfection, and various other dissolved chemicals.
If dilution is inadequate, bather discomfort in the form of chlorinous, irritant gasses can result. Pool operators should be prepared to replace pool water with fresh water as a regular part of their water treatment regime at a rate of 30 litres per bather. The water that is replaced in the backwashing of filters contributes significantly to this requirement.
Dilution rates should be monitored and adjusted according to pool bather usage.
3.9) Bathing load
The maximum bathing load (number of bathers) allowed for at any one time determines the circulation rate, turnover, treatment plant size and other parameters. This bathing load should have been determined at the design stage for the pool. The maximum bathing load takes into account:
The maximum bathing load for each pool must be defined in the PSOP and pool managers shall provide systems controlling entrance to the pool or provide other means of monitoring to ensure that the maximum bathing load is not exceeded.
The starting point for calculating bathing load is the maximum loading of a pool for physical safety: 1 bather per 3m2.
The maximum bathing load should also take into account the capacity of the water treatment plant, using the ratios in Table 1.
|Water depth||Maximum bathing load|
|< 1.0m||1 bather per 2.2m²|
|1.0m to 1.5m||1 bather per 2.7m²|
|> 1.5m||1 bather per 4.0m²|
The operational daily bathing load should be reviewed regularly to determine whether the treatment system is capable of maintaining good water quality. It should be established using this formula:
Operational daily bathing load = 25 to 50% of maximum bathing load x number of hours use per day
The operational daily bathing load for each pool should be recorded, including details of the basis on which it was calculated. If the operational daily bathing load is approached or exceeded frequently, then attention may need to be given to:
3.10) Circulation rate
The circulation rate should be derived from this formula:
Circulation rate (m3/h) = Maximum bathing load x 1.7
The circulation rate and turnover period are related and form the basis for sizing new water treatment plants, and for checking the capacity of existing water treatment plants.
3.11) Turnover period
The turnover period should be calculated from this formula:
Turnover period (h) = water volume (m³)
Circulation rate (m3/h)
3.12) Pool type and turnover
Different sized pools and pools of different types should have turnover periods in accordance with Table 2.
Table 2 Turnover periods for different types of pool
|Pool type||Turnover rate|
|Competition pools 50m long||3 to 4h|
|Conventional public pools up to 25m long with a 1m shallow end||2.5 to 3h|
|Diving pools||4 to 8h|
|Leisure water bubble pools||5 to 20min|
|Leisure water up to 0.5m deep||10 to 45min|
|Leisure waters 0.5 to 1m deep||30 to 75min|
|Leisure 1 to 1.5m deep||1 to 2h|
|Leisure waters over 1.5m deep||2 to 2.5h|
|Teaching/learner/training pools||30 to 90min|
3.13) Maximum bathing load
If the turnover period calculated for an existing pool is longer than the values in Table 2, the maximum bathing load should be reduced using this formula:
Maximum bathing load = Water volume (m³)x 1.7
Turnover period (h)
The turnover period of pools with moveable floors should be appropriate to the pool at its shallowest point (ie potentially biggest bathing load).
The pool hydraulics should ensure appropriate turnover periods and good mixing of water in the pool; short circuits and dead legs should be avoided.
3.14) Dye testing
All pools should be dye tested when first commissioned, to prove the circulation and flow works as specified; And thereafter if there has been remedial work or if there is a circulation problem affecting water quality. See BS EN 15288 1 & 2 and Annex C.
Pool water should circulate 24 hours a day. If the pool has a moveable floor or bulkhead (boom), the circulation system should ensure proper water distribution in all possible positions.
4.1) Surface water removal
Surface water should be removed from swimming pools (a deck-level system is best). Between 50 and 80% (even 100% where the pool has bottom inlets) of the circulation flow should be removed as surface water.
4.2) Inlets and outlets
Inlets and outlets, grilles and covers should be designed in accordance with BS EN 13451-3. They should be inspected visually every day, and once a month subject to closer examination for obstruction, impact damage and vandalism and to make sure that they are correctly in place. If they are damaged or missing, swimming should be suspended immediately.
4.3) Where there is more than one outlet
Outlet systems should be designed in such a way that:
4.4) One outlet
In pools with only one outlet, the grille should be designed in such a way that:
Effective filtration is the primary mechanism for ensuring water clarity. An effective filtration system including coagulation will also remove more than 90% of Cryptosporidium oocysts in a single pass of water-containing oocysts through the filter bed. It is an important function as these oocysts are much more resistant to disinfection than bacteria and viruses.
This CoP specifies filtration standards in terms of medium-rate filters using granular filter media, typically sand. This is a tried and tested method. There are filters that operate at higher rates, some with other media, some applying different filtration principles. These may be able to filter satisfactorily in some conditions, but operators should understand the potential disadvantages and be satisfied that they produce good clarity in the pool. Membrane and ultrafiltration systems are equally suitable and do not require the use of coagulant.
There are many pools in the public sector, where bather loads are not as high or as critical as public community pools (e.g. health clubs, hotels, schools) that use high-rate filtration – over 25 and up to 50 metres per hour. High-rate filters do not filter as well as medium-rate filters. Tests have shown they are about 10 to 25% as effective as medium rate. Accordingly, in these situations the bather loading should reflect the relative inefficiency of these filters (given that turnover and circulation are similar to pools with medium rate filters). Their use should be subject to a risk assessment.
5.1) Filters and filtration rate
Filters will usually be medium-rate pressure filters; 10 to 30m/h is the norm for public sector swimming pools with sand as the main filter medium (other filter media can be used).
5.2) Filter beds
Filters may be either single or multi-grade type. For single-grade filters the sand bed should be a minimum of 800mm deep; for multi-grade filters the sand bed should be a minimum 550mm deep supported on a bed of coarser material 250mm deep.
5.3) Serviceable filters
Every filter should be designed to be serviceable. They should have:
5.4) Annual inspection
The internal condition of the filters and the top of the filter media bed should be inspected annually for corrosion and problems with the filter medium e.g. mud balling, fissures, uneven bed.
A coagulant should be dosed continuously and precisely, by chemical dosing pumps. Continuous low-level dosing of a coagulant is recommended for all pools (except those with membrane and ultrafiltration systems) to improve the filtration efficiency and increase the removal of any contaminants from the pool. This procedure significantly reduces the risk associated with any unseen faecal release.
A wide range of disinfectants is available commercially. This CoP uses hypochlorite as a model for disinfection procedures. This is the commonest disinfectant, especially in public pools. But the CoP does not intend to rule out the use of other effective disinfectant systems, including those that may be developed in the future. The choice of disinfectant should take into account:
6.1) Sodium hypochlorite
Sodium hypochlorite is a liquid supplied with a maximum strength of 15% weight for weight as available chlorine. If a liquid acid is used with it, there should be safeguards to prevent any accidental mixing, resulting in the release of chlorine gas. Sodium hypochlorite can also react vigorously with oxidising materials such as chlorinated isocyanurates.
Sodium hypochlorite can be generated electrolytically from a brine solution. This will elevate TDS levels quicker than the liquid chemical. Flammable hydrogen gas released during the process should be vented safely into the open air. Selection and siting of any electrical equipment associated with the electrolytic generator requires careful consideration.
6.2) Calcium hypochlorite
Calcium hypochlorite is a dry and relatively stable compound, supplied in drums as granules or tablets, with 65-78% available chlorine. Its use in hard water areas can precipitate hardness scale. It must be kept dry and free from contact with all organic materials including paper products, oil and oil products, chlorinated isocyanurates, detergents, cleaning fluids and acids. Such contact causes a heat reaction, and can lead to explosion, fire and the emission of toxic fumes. Contact with acids liberates toxic chlorine gas.
6.3) Chlorinated isocyanurates
Chlorinated isocyanurates are white or off-white granules or tablets with a chlorine odour, stable when dry but in contact with water slowly liberating chlorine. Confusion with other white chemicals must be guarded against. They can explode in contact with calcium hypochlorite, ammonium salts and other nitrogenous materials and will react vigorously with strong acids, alkalis and reducing agents. Cyanuric acid is a byproduct released into the water from dichlor and trichlor. Cyanuric acid makes the chlorine more stable in the presence of sunlight. For every mg of chlorine released almost as much cyanuric acid is added and accumulates in the pool water ultimately making the chlorine ineffective. To prevent this the cyanuric acid content must be diluted by the addition of fresh water.
Bromochlorodimethylhydantoin, in stick or tablet form, is stable when dry but releases bromine in contact with water. It must be dosed using a specific bromine feeder. It is important not to mix the product with other chemicals and to keep it well away from all alkaline substances. Strong concentrations can cause severe burns to the skin and eyes. Its use has been associated with a specific skin irritation affecting bathers.
6.5) Sodium bromide plus hypochlorite
Sodium bromide plus hypochlorite. This is a proprietary system that involves the conversion of bromide to free bromine residual by the reaction of sodium bromide solution with a chlorine donor. The bromide level has to be checked and maintained, for the bromine disinfection to work.
6.6) Chlorine gas
After many years of use in pools chlorine gas from cylinders was no longer recommended by the government in 1978 and is still not recommended by HSE. Methods for its use require a specially designed storage area for the chlorine cylinders. The installation must comply with Control of Substances Hazardous to Health regulation. It is vital to ensure that the building and ancillary areas have been designed to incorporate the requirements for the safe use of chlorine.
6.7) Ultraviolet radiation
Ultraviolet radiation is a secondary disinfection process (used alongside a primary disinfectant, usually chlorine).
It is recommended by PWTAG, both for its capacity to reduce chloramines and kill microorganisms – including chlorine-resistant Cryptosporidium. Its use can reduce the chlorine residual levels necessary to keep pool water healthy. It is increasingly used as an alternative to ozone (which similarly complements chlorination) as it is easier and cheaper to fit, especially to existing plant. (See PWTAG Technical Note 31 Ultraviolet disinfection: specification, maintenance and validation)
Ozone gas can be generated in the plant room and used as a secondary disinfectant. HSE publishes guidance on the safe use of this toxic gas. This includes automatic alarms and shut down in the event of plant failure or indications from leak detectors.
The first priority is to control entry to the pool hall using notices at reception saying that bathers:
Pool water quality would be significantly improved if everyone using the pool showered with soap before entering the pool.
7.2) Babies and young children
The water in ordinary public pools is not suited to very young babies: water temperatures and pool water chemicals may affect sensitive skin. For this reason, parents should be encouraged not to bring children under the age of 6 months to public swimming pools where they share the water with other general swimmers.
All floors in the pool hall area, changing rooms, toilet and shower areas should be thoroughly cleaned each day.
8.1) Cleaning the pool surround
Pool surrounds should be cleaned at the start of each day by washing and scrubbing with 100mg/l chlorinated water (1ml of 10% w/w sodium hypo in 1 litre of tap water).
8.2) Cleaning the water line
Deposits of dirt etc. just above the water line of a freeboard pool can be cleaned off with a chemical-free scouring pad, using sodium bicarbonate or carbonate solution. Operators should wear gloves and goggles.
8.3) Transfer channel
Some pools have a transfer channel fitted with a drain valve, which is capable of being isolated from the pool water system. So for cleaning purposes the pool water level can be lowered (pool circulation stopped) so that water from the pool no longer flows down the channel. Then the transfer channel can be cleaned and it can also be used to take any cleaning residue from cleaning the pool surround. By opening the drain valve and thoroughly flushing, the cleaning residue goes to waste.
8.4) Cleaning agents
Proprietary chemical cleaners should be avoided altogether if possible. They may contain surfactants that affect the monitoring of chlorine residual and cause foaming or phosphates, which promote algal growth. They may contain oxidising agents that give a false reading on water tests. Other compounds simply contain ammonia (they may smell of it) and could produce unhealthy pool conditions (through high combined chlorine levels).
If this is not possible every effort should be made to keep cleaning products out of the pool and any transfer channel. Ideally, there should be some way of draining all poolside washings to waste. Certainly care should be taken to avoid outright incompatibility between cleaning and pool chemicals, which could be dangerous. Chlorinated isocyanurates – often called trichlor or dichlor – can react violently with neat hypochlorites (particularly calcium hypochlorite). In general, reactions between acid and alkalis are potentially dangerous.
8.5) Proprietary cleaners where used
If proprietary cleaners are required, they should be formulated for poolside use, and come from reputable suppliers (even though the target is to prevent them getting into the pool water).
8.6) Chemical cleaning agents and pool water
Chemicals used for cleaning – whether for pool surrounds or the water line – should never be used when there are people in the pool.
8.7) Periodic removal of hard water scaling and body grease
It may be necessary in all wet areas, pool surrounds, showers, changing rooms and toilets to tackle a build-up of lime scale from the water and/or body grease and oils from bathers. Use sodium bicarbonate or carbonate to remove any organic build-up such as body oils or grease. Use an acid-based cleaner (e.g. weak hydrochloric acid/or citric acid) for removing scale. Care should be taken when using acid descalers in the presence of cementitious grout as prolonged contact at too high a strength may dissolve the grout. It is important that no residue from these cleaning programmes returns to the pool water.
Showers should be supplied with fresh water. Shower water should be stored at 60°C, and distributed so that it reaches at least 50°C at the feed to the shower and mixed at or within 2m of the point of use to 40°C (± 2°C).
8.9) Pool covers
Pool covers should be checked regularly for any contamination, cleaned as necessary and disinfected with 100mg/l chlorinated water (1ml of 10% w/w sodium hypo/ 1 litre of tap water).
8.10) Pool equipment
Any equipment, especially floating types, should be checked to ensure they are hygienic and clean before being used in the pool. This includes inflatable play devices, canoes, sub aqua equipment, arm bands, floats etc. They should be regularly cleaned physically, disinfected with 100mg/l chlorinated water solution (1ml of 10% w/w sodium hypo/ 1 litre of tap water) for 20 minutes, and dried prior to storage.
8.11) Transfer channels
Deck-level transfer channels should be cleaned as required, at least once a month. They should be drained and flushed out with 100mg/l chlorinated water (1ml of 10% w/w sodium hypo/ 1 litre of tap water) which can be returned to the balance tank. Grilles should be scrubbed weekly with 100mg/l chlorinated water.
8.12) Balance tanks
Balance tanks should be inspected at least once a year and cleaned as necessary. Debris should be removed and inner surfaces brushed and flushed down with 100mg/l chlorinated water (see 8.1), which can be returned to the circulation system via the filters.
8.13) Pool bottom
The pool bottom should be kept clear of contamination, algae, and general debris by daily sweeping, suction cleaning or other means.
8.14) Pool shell
If a pool is emptied, then the bottom and sides should be scrubbed thoroughly with 100mg/l chlorinated water (1ml of 10% w/w sodium hypo/ 1 litre of tap water) before refilling. It should be flushed thoroughly to drain before refilling. Check the integrity of the structure while the pool is empty.
All operators should have, as part of the EAP, written procedures, which are practised and effective for dealing with the contamination involving faeces, blood and vomit. Faeces present the biggest risk, not least because of the threat from the chlorine-resistant protozoan Cryptosporidium (and its cousin Giardia).
This section largely duplicates PWTAG Technical notes 2 and 17 on the PWTAG website. There is further information on the subject in note 30.
9.1) Assess the risk
If faecal contamination has only been reported, and there is some doubt about the accuracy of the report, its presence should be confirmed by pool staff. If it cannot be confirmed, pool operators should assess the risk and may decide that the risk of harmful contamination is low and allow bathing to resume. This assumes that pH and disinfection are within normal limits.
9.2) Solid faeces
Solid faeces are relatively easy to deal with. It is unlikely that the perpetrator is suffering from an acute gastrointestinal illness and the microorganisms in it are relatively contained.
9.3) Runny faeces
If the stool is watery, runny or soft (something like diarrhoea), the risk of infection is greater: the perpetrator is more likely to be carrying enteric pathogens, and if so they are likely to be spread through the pool water. It will certainly be impossible to remove the faecal material as it is with solid stool.
In most cases of diarrhoea in a swimming pool, the operator will not know if Cryptosporidium is involved. So the safest option is to assume that it is and immediately close the pool. There are in principle three procedures that will in time remove Cryptosporidium - coagulation/filtration, UV and superchlorination. The procedures to be followed primarily depend on the efficiency of the pool's filtration.
9.4) Pools with medium-rate filtration (up to 25 metres per hour)
This should include most public pools. Here the main emphasis is on filtration, which if effective should remove some 90% of theCryptosporidiumoocysts in each pass of pool water through the filter. This, then, is the procedure.
9.5) Pools with high-rate filtration (over 25 and up to 50 metres per hour)
High-rate filters do not filterCryptosporidiumo ocysts, or anything else, as well as medium-rate filters. But because many pools have them, it is important to know how to deal with faecal contamination.
The main emphasis is on superchlorination (see also below and the PWTAG technical note 23 on superchlorination). High-rate filters without coagulation remove as little as 10% of Cryptosporidiumo ocysts in each pass. Even with coagulation, and perhaps 50% removal, it could take two days to be safe. The procedures below also apply to tier filters.
9.6) Pools with no filtration (fill and empty pools)
Here there is the possibility of emptying the pool altogether. This might apply to a paddling or plunge pool, for example. For any pool, if operators are confident that they can safely empty the pool, this is the procedure that should be followed.
Pool disinfectants should kill any pathogenic microorganisms in blood or vomit, provided disinfectant residuals and pH values are within recommended ranges. But there are some precautions to take.
It is not unusual for swimmers to vomit slightly. It often results from swallowing water, or over-exertion, and so is very unlikely to present a threat through infection. PWTAG recommends that vomit occurrences of this nature in the pool should be treated as if it were blood. But if the contents of the stomach are vomited into a pool, the bather may be suffering from a gastrointestinal infection. And if that is cryptosporidiosis, infective, chlorine-resistant Cryptosporidium oocysts will be present. In this case the procedures outline above in 9.3 to 9.5 should be carried out
9.9) Contamination of pool surround
Any blood or vomit spillage on the poolside should not be washed into the pool or poolside drains and channels. Instead, like blood spillage anywhere in the building, it should be dealt with using strong disinfectant - of a concentration equivalent to 10,000mg/l of available chlorine. A 10:1 dilution of the sodium hypochlorite in use may be convenient. Using disposable gloves, the blood should be covered with paper towels, gently flooded with the disinfectant and left for at least two minutes before it is cleared away. On the poolside, the affected area can then be washed with pool water (and the washings disposed of - not in the pool). Elsewhere, the disinfected area should be washed with water and detergent and, if possible, left to dry. The bagged paper towels and gloves are classed as offensive/hygiene waste, which in only small quantities may be disposed of with the general waste.
There should be documented procedures for the use of the test kits and other test equipment, and operators should be given full training in their use for monitoring pool water quality.
The documented procedures should detail actions for operators to take if there are unexpected test results, especially if they show the pool water chemical composition is either below or exceeding safe limits.
10.1) Pool water testing equipment
The manual monitoring and measurement of the chemical condition of the pool water should be performed using appropriate test kits and following manufacturers' instructions. The accuracy of test kits should be maintained by:
10.2) Automatic monitoring of chemical levels
The readouts from the controller should be checked daily against the results from manual tests of the sample cell. The manufacturer's recommendations for the calibration of such equipment, including the use of suitable test solutions, should be followed. Records of all calibration tests and results should be recorded on log sheets and retained.
Calibration for pH should incorporate the use of two buffer solutions, normally pH4 and pH9.2. Single-point calibration is not recommended. Readouts from the controller should be checked daily against the results from manual tests of the sample cell. If the difference is more than 0.2, the controller should be recalibrated
Readouts from the controller should be checked daily against the results from manual tests of the sample cell. If the difference is more than 15%, the controller should be recalibrated after first confirming the result with a further manual test.
Automatic monitors require checking daily to ensure that the readings are correct. They do not mean that manual testing of water from the pool itself is unnecessary, although the frequency may be reduced - from every two hours for manual systems to no less than three times a day with automatic systems. Automatic control does not monitor combined chlorine to ensure adequate control of chloramines, chemical testing may need to be more frequent.
10.3) Chemical testing of pool water
Where disinfection and pH are not monitored and controlled automatically by the water treatment plant, manual testing is needed, using commercially available test kits and the appropriate tablets. The frequency of chemical testing should be determined by the risk assessment, but recommended test intervals are:
10.4) Sampling points
Pool water samples for chemical analysis should be taken from the pool at a depth of 100-300mm (not from the sampling cell in automatic monitoring equipment). They should routinely be taken at the deep end and furthest from the inlets - the most vulnerable part of the pool - and occasionally elsewhere.
10.5) Free chlorine levels
The values below - indeed, any values - require validation by satisfactory bacteriological water quality standards
For all pools using hypochlorite, assuming the pH value is 7.2, the free chlorine levels should be maintained at 1mg/l or below, to an absolute minimum of 0.5mg/l. This assumes satisfactory microbiological monitoring results (see section 11).
The use of secondary disinfection (UV or ozone) can help minimise the required free chlorine levels. These values can be achieved only where the pool is designed and engineered and operated well with effective pre-swim hygiene and not overloaded.
Free chlorine levels above 3mg/l should not be necessary in any pool using hypochlorite. If this is exceeded, dosing should be reduced.
If dosing has gone wrong and free chlorine reaches 5mg/l, chlorination should be stopped immediately if free chlorine continues to rise bathing should cease until the fault has been rectified and the residual is under control.
The same principle applies to pools on chloroisocyanurates (or with cyanurates added as a chlorine stabiliser). Chlorine residuals of up to 5mg/l may be necessary in normal operation. For pools using chlorinated isocyanurates as disinfectant, free chlorine should be maintained at 2.5-5mg/l and the cyanuric acid at no more than 150mg/l.
Some automatic controllers may not be accurate in the presence of cyanuric acid and their compatibility should be checked.
10.7) Combined chlorine levels
The level of combined chlorine residuals should be as low as possible. Combined chlorine levels should be less than half the free chlorine, and no more than 1mg/l no matter what the level of free chlorine.
If this ratio of combined to free chlorine is unsatisfactory, some correction may need to be applied (see Swimming Pool Water: treatment and quality standards for pools and spas).
10.8) pH value
The pH values for the pool water should be maintained within the range recommended for the disinfectant being used. But a pH value of between 7.2 and 7.4 should be the target when using chlorine-based disinfectants. At levels above this range the free chlorine will not be so effective and accordingly may need to be increased.
To ensure effective coagulation and a stable pH when using acidic disinfectants, alkalinity in pool water should be maintained at a level between 80 and 200mg/l (measured as CaCO3).
Alkalinity measurements should be taken weekly, using commercially available alkalinity test kits and the appropriate tablets. Dilution or dilute acid should be used to lower the levels of alkalinity.
10.10) Calcium hardness
Pool water should be maintained for bather comfort, and grout should withstand that water.
Ideally calcium hardness should be maintained between 75 and 150mg/l as CaCO3.
However, in areas with a hard water supply this cannot be practically achieved. It is therefore very important that water treatment chemicals do not further enhance the calcium hardness content over and above that in the hard water make up supply.
Calcium hardness concentrations higher than 300mg/l may result in the deposition of scale with sudden changes in temperature and pH.
Calcium hardness measurements should be taken weekly, using commercially available test kits with the appropriate tablets.
10.11) Total dissolved solids (TDS)
Dissolved solids are aggressive at high levels and should not be allowed to rise more than 1,000mg/l above the level in the source water. (There are exceptions for electrolytically generated chlorine, see PWTAG Swimming Pool Water). TDS concentration should be reduced by dilution if necessary. TDS concentration should be measured weekly, using a commercially available electronic meter that has been calibrated against a commercially available standard.
Sulphate levels should be maintained below 360mg/l. Sulphate levels should be measured once a week using a commercially available test kit.
10.13) Balanced water
It is important to maintain the water in balance, but usually this is achieved when the pH is properly controlled. Alkalinity, calcium hardness, TDS and temperature are also factors.
The Langelier index is a formula that brings together all these factors. It makes sense to calculate Langelier weekly when measuring alkalinity, calcium hardness and TDS .
Swimming pool water should be microbiologically tested each month to monitor for the presence of potentially harmful microorganisms. Testing should be performed only by competent personnel at a UKAS-accredited laboratory.
Tests should also be done
More frequent sampling will be necessary if there is a problem, or for particularly heavily loaded pools. Hydrotherapy pools, even those not in a healthcare setting, should be tested weekly.
11.1) Chemical testing at the same time
Whenever a microbiological sample is taken it is important that a pool water chemical test of free and combined chlorine and pH is taken at the same time, from the same location as a reference. The water clarity and the bather load should also be noted.
11.2) Aerobic colony count (ACC)
Aerobic colony count also commonly known as Total Viable Count (TVC) at 37°C is the basic test for pool water quality and is a measure of the aerobic bacteria present in the water. It does not necessarily give an indication of microbiological safety, but gives valuable information on the general quality of the pool water and whether the filtration and disinfection systems are operating satisfactorily.
11.3) Escherichia coli (E coli)
Escherichia coli is a bacterium that is normally only found in human and animal faeces and does not grow in water. The presence of E coli indicates the presence of recent faecal contamination in the water. E coli should be absent in a 100ml sample.
Coliforms are related to E coli but may also be found in soil and on vegetation. Their presence therefore indicates some external contamination of the pool water.
11.4) Pseudomonas aeruginosa
Pseudomonas aeruginosa is an opportunistic pathogen capable of growing in water even at relatively low temperatures. It will readily colonise filters, deck level transfer channels, balance tanks and flexible polymeric materials used in some inflatables, tubing and pool covers. Most species of Pseudomonas are non-pathogenic for healthy people, but Pseudomonas aeruginosa can cause skin rashes and ear infections.
11.5) Acting on failures
These procedures should be included in the emergency action plan
The pool should be closed if there is chemical or physical evidence of unsatisfactory disinfection eg poor clarity or low free chlorine concentration.
The pool should also be closed if microbiological testing discloses gross contamination, which means one of two things:
1 E. coli over 10 per 10 ml PLUS either colony count over 10 cfu per ml or Pseudomonas aeruginosa over 10 per 100ml (or, of course, both)
The plant room should be a secure area for authorised personnel only. Plant rooms should be adequately sized and not used for general storage, or for storing hazardous chemicals, unless appropriate precautions are taken. There should be no risk from fire or overheating.
Chemicals should be stored in containment structures or devices designed to control spillages. There should be adequate separation from other chemicals and substances stored in the plant room containers should be kept securely closed, cool and dry. Chemicals supplied in paper or plastic sacks should be stored in plastic bins before opening, and securely closed after use.
12.1) Plant room protocol
It is essential that temperature, humidity and ventilation are controlled for the equipment and its use. Four air changes per hour is the usual minimum but this will increase where ozone treatment is used.
Plant, including electrical equipment, should be inspected and maintained in accordance with a planned programme.
12.2) Automatic equipment maintenance
Automatic monitoring and control equipment should be maintained and calibrated in accordance with the manufacturer's recommendations.
12.3) Safety systems provided and maintained
Relevant safety systems (e.g. chlorine gas detectors, fire/smoke detectors), safety equipment and personal protective equipment should be in the plant room, and should also be maintained in accordance with a planned programme. Monthly inspection of personal protective equipment is required to check its continuing suitability.
12.4) Confined spaces
Cleaning or maintenance activities may require employees or contractors to enter confined spaces. A confined space is a place which is substantially enclosed (though not always entirely, for example a pool balance tank after it is emptied) and where serious injury can come from hazardous substances or conditions within the space or nearby (e.g. lack of oxygen).
If work is required on plant or equipment in confined spaces pool operators should have arrangements in place to ensure the work can be done safely. The following principles apply:
Detailed guidance on managing the risks from work in confined spaces is available at http://www.hse.gov.uk/confinedspace/
Every employer has a responsibility to assess the risks associated with hazardous substances in the workplace and to take adequate steps to eliminate or control those risks. The chief relevant legislation are the Control of Substances Hazardous to Health Regulations 2002 (COSHH)
COSHH applies to pool chemicals and to microorganisms.
Only where prevention is not reasonably practicable can the pool operator turn to other controls. Personal protective equipment should not be the first option. Instead, the risk must be reduced to acceptable limits by using the least potentially harmful (but effective) chemical or 'engineering' control measures by isolating or physically separating chemicals.
These procedures must be systematically recorded to include:
COSHH Regulations require suppliers of chemicals to provide a safety data sheet (SDS) for each chemical. These should be displayed in the vicinity of the chemicals. It is also the plant installer's responsibility to provide relevant information on plant safety etc. - which may include SDSs.
There will need to be SDSs for all the chemicals in the plant room including pool chemicals, cleaning chemicals, pool water testing chemicals and chemicals used in maintenance programmes.
13.2) Training in chemical handling
COSHH Regulations require that all staff involved in the handling and use of chemicals should receive appropriate training and instruction. This may include lifeguard staff and cleaning staff. Training should include the knowledge and understanding of the chemicals needed for staff to be alert to any changes affecting safety.
The training for the safe operation and use of equipment and chemicals should be:
13.3) Personal protective equipment (PPE)
The Personal Protective Equipment Regulations 2002 and Personal Protective Equipment at Work Regulations 1992 (as amended) require pool operators to assess and provide necessary personal protective equipment (PPE) when performing certain tasks. HSE publications HSG53 and INDG174 give full guidance.
Pool operators should take the advice of suppliers about what PPE is needed. Some or all of the following protective clothing may be needed during delivery, handling of materials, cleaning or maintenance: dust masks and face protection, eye protection (to BS EN 166:2002) aprons or chemical suits boots gauntlets respirators.
Pool operators need to consider suitable emergency procedures for more serious chemical gas formation or leaks, where appropriate in consultation with the fire authorities.
13.4) Chemical spillage
Any spillage should be cleared away using a safe method agreed between chemical supplier and pool operator. The method should be displayed on a notice, together with the provision of the necessary equipment and its location. Care should be taken to prevent any chemical from entering a drain unless it is safe to do so.
13.5) Toxic gas leaks
There should be an emergency action plan (EAP) for dealing with any major release of toxic gas. The procedure should include arrangements for any necessary evacuation and co-ordination with emergency services, including informing them immediately of hazardous substances present (unless they already have this information).
13.6) Safety information on site
Precaution cards and first aid instructions should be displayed for each chemical. CAS and EINECS numbers should be included on the precaution cards so that in the event of an accident emergency services will know what is the correct medical treatment.
13.7) First aid
First aid provision should include equipment for dealing with the consequences of direct contact with chemicals for example, by providing eyewash bottles and emergency drench showers.
13.8) Delivery of chemical
Everyone involved in the transport, handling and storage of dangerous goods (some forms of pool chemicals) by law needs training appropriate to their duties, with periodic refresher training.
Procedures and training for dealing with chemical deliveries should be established and understood by all staff.
Bulk delivery of sodium hypochlorite and hydrochloric acid
There should be documented procedures for transfer and handling during delivery. Suppliers should be required to comply with these procedures.
Transport from offloading area to store
It is important that the chemical containers should be taken to a suitable storage area as soon as possible should not be left unattended in an offloading area are kept upright and never rolled and are used in stock rotation.
13.9) Chemical storage essentials
Each chemical should be stored separately from all other chemicals.
13.10) Chemical store
Chemical stores should provide clean and dry storage for solid materials to avoid contact with water and should also be protected from sunlight and hot pipework or plant. Chemical stores should:
13.11) Dosing practice
In general, the most effective dosing systems are also the safest for bathers and operators. Automatic dosing (disinfectant and pH values kept to set limits in response to continual monitoring) is preferred but manual testing of the pool water is required to verify its operation.
The dosing system should be backed up by regular monitoring and verification.
Hand dosing in normal operation should not happen. It is rarely justified and only after all relevant health and safety issues have been settled. No chemicals should be added to the pool while bathers are in it, nor should bathers be readmitted until all materials have been fully dissolved and dispersed.
Where to dose
Dosing disinfectant before the filter prevents inadvertent mixing of disinfectants and acids (which are added post-filter). But there are arguments for disinfectant dosing post-filter (this issue is dealt with in Swimming Pool Water: treatment and quality standards for pools and spas). With UV and ozone (which remove or reduce residual chlorine), dosing is always after the secondary treatment.
Circulation feeders, which hold tablets of disinfectant, should be used only in accordance with the manufacturer's instructions.
13.12) Chemical dosing operations
Chlorine gas can be generated and an emergency arises where disinfection chemicals mix inadvertently with pH correcting chemicals. This can happen when pool chemicals continue to be dosed when main pump circulation fails.
13.13) Chemical line safety
13.14) Scaling of chemical lines and pumps
To prevent scale, hypochlorite disinfectant chemicals can contain polycaroxylate, sodium hexametaphosphate or may be diluted prior to injection. Any scale should be removed by rodding.
13.15) Preparing dosing chemicals
Maintaining satisfactory environmental conditions is essential for the comfort of bathers, lifeguards, staff, spectators etc., and for the pool to operate successfully over its working life.
14.1) Pool water heating
Table 3 gives recommended temperature ranges for different types and use of pool
Table 3 Pool Temperatures
Temperature range (°C)
Competitive swimming and diving, fitness swimming, training
Recreational swimming and adult teaching
Babies, young children, disabled and infirm
Hydrotherapy and aquatic rehabilitation pools
Ideally at 34.5?C (thermoneutral).
14.2) Pool hall air
For the purposes of this CoP, the following terms and definitions apply.
16.1) The Law
This section is provided to aid awareness and understanding. It looks at the legislation and court judgements that affect safety and outlines your responsibilities under the law. References in this chapter are to legislation for England and Wales. There are differences in the legislation in Scotland (also covered here).
Someone injured through your negligence can bring an action for damages against you in a civil court of law. If you are found negligent, you may be ordered to pay compensation for loss of earnings, medical expenses, pain, suffering and the like.
Claims for damages after accidents are perceived to be on the increase, with solicitors and accident claim practitioners touting for new business by offering no win no fee terms. Concern about the growth of the compensation culture led to the introduction of the Compensation Act in 2006. This brought in changes to the law on liability and breach of statutory duty aimed at tackling perceptions that can lead to a disproportionate fear of litigation and risk-averse behaviour. Despite this, Lord Young states in his 2010 report Common Sense, Common Safety, the problem of the compensation culture prevalent in society today is one of perception rather than reality. The number of claims for damages due to an accident or disease has increased slowly but nevertheless significantly over recent years. Furthermore, there is clear evidence that the public believes that the number of claims and the amount paid out in damages have also risen significantly.
Not only organisations but also individuals can face prosecution in a criminal court for not complying with legal duties imposed by government legislation. You can be fined, or even face imprisonment, if found guilty in a criminal court.
16.2) Criminal law
Health and Safety Legislation
Health and Safety at Work etc. Act 1974
A criminal offence will arise from a failure to comply with legal duties imposed by the Health and Safety at Work etc. Act 1974 (HSWA) and regulations made under it.
This legislation places a duty on employers to ensure, as far as is reasonably practicable, that in the course of conducting their undertaking, employees and members of the public are not put at risk.
The phrase 'conducting their undertaking' also includes cleaning, maintenance and repair of the plant, machinery and buildings necessary for carrying on the business. The employer cannot delegate responsibility for this duty. Therefore, in effect, you need to consider the consequences of the actions of contractors as well as your employees.
You need to consider the cost and effectiveness of any precautions that you can take to minimise risk of harm. If a precaution is cheap, easy to take and is very effective, then it is reasonable to implement it even if the risk of harm is small. If the risk of harm is great, then more expensive precautions may be reasonable.
16.3) Enforcement of health and safety legislation
Responsibility for the enforcement of health and safety legislation rests with the Health and Safety Executive (HSE) and local authorities. Their inspectors have powers to investigate incidents and complaints or carry out routine inspections. When there has been a breach of health and safety law the enforcing authority can serve improvement or prohibition notices or prosecute.
The local authority will be the enforcing authority for most privately owned pools whereas the HSE is responsible for public pools.
Where an offence is committed with the 'consent, connivance or neglect of any director, manager, secretary or other similar officer', that person may be guilty of an offence along with the organisation. If the breach in the law results in death, the police are involved and they may refer the case to the Crown Prosecution Service.
16.4) The Corporate Manslaughter and Corporate Homicide Act 2007
This created a criminal offence of corporate manslaughter in England, Wales and Northern Ireland and corporate culpable homicide in Scotland. This Act applies to all companies, most government bodies, partnerships, trade unions, employers' associations and incorporated charities. Crown immunity has been largely abolished. The Act does not apply to unincorporated bodies such as some charities, friendly societies etc., or individuals.
Corporate manslaughter and corporate homicide investigations are led by the police. They can be lengthy and intrusive. The existing provisions of the HSWA still apply.
16.5) Control of Substances Hazardous to Health Regulations 2002 (as amended) (COSHH)
Chemicals and microorganisms that may cause ill health are subject to the Control of Substances Hazardous to Health (COSHH) Regulations 2002 (as amended). These Regulations require an employer or self-employed person to:
16.6) Management of Health and Safety at Work Regulations 1999 as amended
The Management of Health and Safety at Work Regulations 1999 require you to carry out risk assessments to identify hazards and take any necessary steps to reduce the risk of an incident. Regulation 3(1)(b) states: Every employer shall make a suitable and sufficient assessment of&mdash
(a) The risks to the health and safety of his employees to which they are exposed whilst they are at work
(b) The risks to the health and safety of persons not in his employment arising out of or in connection with the conduct by him of his undertaking
In effect (b) means that your risk assessments should consider the risks to visitors you invite onto your property, or other people who might be affected by your undertaking or your activities.
Regulation 5 states:
'Every employer shall make and give effect to such arrangements as are appropriate, having regard to the nature of his activities and the size of his undertaking, for the effective planning, organisation, control, monitoring and review of his preventive and protective measures.'
Where the employer employs five or more employees, the arrangements should be recorded.
16.7) Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1999 (RIDDOR)
You are legally bound under RIDDOR to report within 7 days certain accidents, dangerous occurrences and types of ill health to the enforcing authority. They may well send an inspector to investigate. The authority will also investigate complaints made by members of the public. It is essential that you are able to demonstrate that you have effective procedures in place to identify and manage risk
16.8) Public Health legislation
The Health Protection Regulations 2010 (England & Wales) apply
Where voluntary cooperation to avert a health risk cannot be secured and where other methods of control are ineffective, unsuitable or disproportionate to the risk involved.
The Department of Health has published guidance that was written by Public Health England and the Chartered Institute of Environmental Health, which describes how these powers should be used. [link/ref?]
Powers that impose restrictions or requirements are conditional. The local authority makes an application to a magistrate who must be satisfied that the relevant criteria are met. The criteria cover evidence of infection or contamination, assessment of the potential for significant harm to human health, risk of spread to others and necessity for action to be taken in order to reduce or remove that risk. The legislation also contains various safeguards for people who might be subject to the legal measures.
The measures are contained in the Public Health (Control of Disease) Act 1984 (as amended) together with the Health Protection (Local Authority Powers) Regulations 2010 and the Health Protection (Part 2A Orders) Regulations 2010 .
16.9) Civil law
The foundation of most personal injury actions is in proving negligence under common law. An action for damages is brought in the civil courts.
To win an action and be awarded compensation the injured person must be able to demonstrate that they were owed a duty of care, and there was a breach of that duty leading to the injury.
A civil case can also be brought for breach of statutory duty that results in injury or ill health.
Common law duties essentially derive from decisions made by judges over the years. Under common law you owe someone a duty of care if there is:
Proximity can be geographical, contractual, or through a care relationship (for example between teacher and child). If you breach that duty of care, and foreseeable physical or psychological damage results, then you are liable to negligence. Employers may be held liable for the negligence of their employees (this is called vicarious liability).
Visitors must take reasonable care for their own safety. If they don't and come to harm, then their 'contributory negligence' would lessen any claim against you.
Note that children cannot be expected to appreciate dangers in the same way as adults. It is highly unlikely that contributory negligence could be attributed to the actions of a very young child. Adults, however, will be expected to exercise responsibility for children in their care.
In civil law, the duty of care has been further defined by legislation.
Under the Occupiers' Liability Acts of 1957 (OLA57) and 1984 (OLA84), the occupier of premises owes a duty of care to lawful visitors (OLA57) and trespassers (OLA84), by reason of the state of the premises and things done or omitted to be done on them. In Scotland, a similar duty of care is owed under the Occupiers' Liability (Scotland) Act 1960.
The 'occupier' is the person or body that has sufficient control over the premises to be in a position to take the steps necessary to protect people who otherwise may be at risk.
If there is more than one occupier, each owes a duty of care that is in relation to the degree of control each has over the premises.
An occupier has the duty of care and cannot delegate this duty to someone else. So, in effect, you may be responsible for the actions of contractors working on your behalf.
Under Section 2(2) of the OLA57, the occupier has:
A duty to take such care as in all the circumstances of the case is reasonable to see that the visitor will be reasonably safe in using the premises for the purposes for which he is invited or permitted by the occupier to be there.'
Warning a visitor of dangers might be sufficient to absolve you from liability, but only if it was sufficient to enable the visitor to be reasonably safe.
Under OLA57, you can choose to restrict or exclude your liability by imposing entry conditions. However, the Unfair Contract Terms Act 1977 says:
'A person cannot by reference to any contract term or to a notice exclude or restrict his liability for death or personal injury resulting from negligence.'
In the case of other loss or damage, liability can be excluded or restricted only if the terms are reasonable.
17.1) Model Pool Technical Operational Procedures
What a pool technical operational procedures look like:
Our intention is to always provide a swimming pool technical operation that is safe, healthy and environmentally friendly. We shall maintain compliance with the PWTAG Code of Practice and where relevant other national and European standards.
The person responsible for writing and reviewing the PTOP for this pool is ........................................................
We carry out a formal review of our written plan on an annual basis and or whenever we carry out major adaptations, or if there is a notable incident affecting pool water safety.
We provide training and qualification for the key staff at the pool which is always maintained within currency requirements and /or employ certified personnel to undertake key roles as essential to comply with PWTAG Code of Practice
For this pool, we always ensure that a Swimming Pool Technical Operator is on duty during all hours of the pools operation.
25m x 12.5m public pool with 12.5 X 8m teaching pool open to the public from 7am to 10pm Monday to Friday and 7am to 8pm Saturday and Sunday 50 weeks of the year.
Our simple schematic plan of the pool is attached
Medium rate sand filters
100 % surface water removal
Turn over period 3 hours
Maximum capacity bathers 100 bathers
Disinfection is Sodium Hypochlorite
pH correction is CO2
Nb include the relevant clauses of PWTAG CoP sections 3 to 14
6.1 water treatment
The water treatment system for the pool is based upon PWTAG requirements, European and national standards and takes into account
6.2 Public health hazards
Our risk assessment for this pool considers the following hazards:
6.3 Mains water quality
Our water treatment system takes into account the mains water characteristics
6.4 Pool water clarity
We monitor pool water quality to ensure no danger to bathers
6.5 Primary disinfection
Our primary disinfection is sodium hypochlorite which is monitored and dosed automatically.
6.6 Secondary disinfection
This pool uses UV to help prevent the threat from Cryptosporidium and to limit combined chlorine. The system installed and dosed in accordance with PWTAG requirement
6.7 Dilution with fresh water
We replace pool water with fresh mains water as a regular part of the water treatment regime with up to 30 litres per bather according to pool bather usage.
6.8 Bathing load
The maximum bathing load (number of bathers) allowed for at any one time is ...........................................
6.9 Turnover period
The turnover period for this pool is ...................................
6.10 Dye testing
This pool was dye tested when first commissioned.
6.11 Water circulation
This pool operates the water treatment system continuously.
6.12 Surface water removal
This pool uses a deck level surface water removal system and bottom drains. 80% of the water removal is from the surface.
6.13 Inlets and outlets
Inlets and outlets, grilles and covers are in accordance with BS EN 13451-3. They are inspected visually every day, and once a month subject to closer examination for obstruction, impact damage and vandalism and to make sure that they are correctly in place. If they are damaged or missing, swimming is suspended immediately.
6.14 Filters and filtration rate
This pool uses medium-rate pressure filters with sand as the main filter medium.
6.15 Serviceable filters
The filters are designed in accordance with PWTAG requirements.
6.16 Annual inspection
The filters are inspected annually for corrosion and problems with the filter medium.
Filters are backwashed at least once a week and whenever the pressure loss across the filter media bed reaches the level specified, at the end of bathing for the day.
Our filters have flow meters fitted between the circulation pumps and filters to monitor the system's flow rate during normal operation, and backwashing rate.
We dose PAC continuously, at a rate of 0.1ml/m3 of the total flow rate.
6.19 Bather hygiene procedures
We have notices at reception saying that bathers:
6.20 Pre-swim hygiene
We provide pre-swim showers and toilets en-route to the pool and encourage everyone to use them before swimming. Hand washbasins with liquid soap and hand-drying facilities are provided. Staff and notices enforce all operational procedures including when not to use the pool during and after diarrhoeal illness.
6.21 Babies and very young children
We have special periods when babies and very young children are encouraged to use the pool. We insist that babies use appropriate swim wear to help prevent faecal release in the pool and provide excellent baby changing facilities
6.22 Pool cleaning - equipment and surfaces
All floors in the pool hall area, changing rooms, toilet and shower areas are thoroughly cleaned each day. We ensure that floor-cleaning materials do not enter the pool water
Showers comply with HSG 274 part 2 The control of legionella bacteria in hot and cold water systems and are cleaned and descaled in accordance with HSG 274 part 2 requirements.
6.24 Pool covers
Pool covers are checked regularly for any contamination and cleaned as necessary with 100mg/l chlorinated water.
6.25 Pool equipment
All equipment is checked to ensure it is hygienic and clean before being used in the pool.
6.26 Transfer channels
Deck-level transfer is cleaned as required, at least once a month.
6.27 Balance tanks
Balance tanks are inspected at least once a year and cleaned as necessary.
6.28 Pool bottom
The pool bottom is kept clear of contamination, algae, and general debris by daily sweeping, suction cleaning.
6.29 Monitoring water quality
We have documented procedures for testing the pool water, which follow the guidance of PWTAG and the kit instructions, and operators are given full training in their use for monitoring pool water quality. The documented procedures include detail actions for operators to take if there are unexpected test results, especially if they show the pool water chemical composition is either below or exceeding safe limits.
We test the water chemically every 2 hours and the target levels for pH and disinfection are pH7.0 to 7.4
Free chlorine 0.5mg/l to 1.0mg/l
Combined Chlorine nil or up to a maximum of 0.5mg/l
On a weekly basis, we test the water for balance and chemical levels
Alkalinity between 80 and 200mg/l
TDS no more than 1000 above the source water
Calcium hardness between 75 and 150mg/l
Automatic monitoring of chemical levels
The readouts from the controller are checked daily against the results from manual tests of the sample cell. The manufacturers' recommendations for the calibration of the equipment, including the use of suitable test solutions, are followed. Records of all calibration tests and results are recorded on log sheets and retained.
Readouts from the controller are checked daily against the results from manual tests of the sample cell. If the difference is more than 0.2, the controller is recalibrated
Readouts from the controller are checked daily against the results from manual tests of the sample cell. If the difference is more than 15%, the controller is recalibrated after first confirming the result with a further manual test.
6.30 Microbiological testing
The swimming pool is microbiologically tested each month to monitor for the presence of potentially harmful microorganisms by the following UKAS-accredited laboratory.
Tests are also done
The required microbiological conditions are in accordance with the PWTAG Code of Practice.
6.31 Acting on failures/pool closure
Step 1 If a result is unsatisfactory, a preliminary investigation is undertaken and the test repeated as soon as practicable.
Step 2 If the second result is also unsatisfactory, we investigate further and the test repeated.
Step 3 If the third result is still unsatisfactory, we take immediate remedial action.
6.32 plant room
The plant room is a secure area not accessible by unauthorised persons. It is not used for general storage, or for storing hazardous chemicals, unless chemicals are in containment structures or devices designed to control spillages with adequate separation from other chemicals and substances stored in the plant room.
Plant, including electrical equipment is inspected and maintained in accordance with a planned programme.
6.33 Safety systems provided and maintained
Relevant safety systems and safety equipment and personal protective equipment is held in the plant room, maintained in accordance with a planned programme. Monthly inspection of personal protective equipment is carried out to check its continuing suitability.
6.34 Confined spaces
Staff are not permitted to work in confined spaces.
6.35 Chemical safety - COSHH
Pool management ensure a competent person assess the risks associated with hazardous substances in the workplace and that we put in place procedures to eliminate or control those risks.
These procedures are systematically recorded to include:
We ensure SDSs are provided and available for all the chemicals in the plant room including pool chemicals, cleaning chemicals, pool water testing chemicals and chemicals used in maintenance programmes.
6.36 Training in chemical handling
W provide all staff involved in the handling and use of chemicals with appropriate training and instruction.
6.37 Personal protective equipment (PPE)
Pool management take the advice of suppliers about what PPE is needed and ensure that this is provided and maintained:
6.38 Chemical spillage
Any spillage is cleared away using a safe method agreed between chemical supplier and pool operator. The method is displayed on a notice, together with the provision of the necessary equipment and its location.
6.39 Safety information on site
Precaution cards and first aid instructions are displayed for each chemical.
6.40 First aid
First aid provision including equipment for dealing with the consequences of direct contact with chemicals is provided which includes.
6.41 Delivery of chemicals
Everyone involved in the transport, handling and storage of pool chemicals receives initial and refresher training in the procedures involved.
Deliveries proceed only when a trained staff member is available to receive and check the materials.
6.42 Bulk delivery of sodium hypochlorite and hydrochloric acid
There are documented procedures for transfer and handling during delivery. Suppliers help to establish and must comply with these procedures.
Pipework is clearly labelled and specific to the delivery of that product, Pipework fill points are clearly labelled and locked when not in use.
6.43 Transport from offloading area to store
Chemical containers are taken to a suitable storage area as soon as possible not left unattended in an offloading area are kept upright and never rolled and are used in stock rotation.
The method of handling chemical containers is described in these procedures and staff informed and trained in these.
6.44 Chemical store
Chemical stores are kept clean and dry for the storage of solid materials, protected from sunlight and hot pipework or plant. Chemical stores have warning signs, are secure and accessible only to authorised, appropriately trained people.
Hand dosing in normal operation is not permitted at this pool.
6.46 Chemical dosing operations
Written procedures are provided for day tank filling, mixing or diluting chemicals and cleaning injectors.
Chemical dosing systems monitors and automatic controls are interlinked with the circulation pumps and the circulation of water through the system, so that dosing stops if there is pump failure or significant loss of pumping rate. These systems are designed to always fail to safety and require manual restart when circulation is restored.
All chemical pipework, suction lines, delivery lines and tanks is marked to identify the contents and the direction of flow.
All pipes used for delivery of chemicals to injection points are double sheathed.
Disinfectant and pH dosing systems are kept separate.
Dosing sets are separated in individual bunds.
6.49 Preparing dosing chemicals
Chemicals are added to water and never the other way round when preparing solutions.
Non-liquid chemicals are kept dry until dissolved in water.
6.5 Heating and air circulation
This pool maintains the following temperatures
Temperature range (°C)
Competitive swimming and diving, fitness swimming, training
Recreational swimming and adult teaching
Babies, young children, disabled and infirm
6.6 Pool hall air
The pool hall air temperatures are maintained at no more than 1deg C above or below that of the water temperature. Air temperatures over 30°C are not permitted.
Relative humidity is maintained at a level of 60% (no less than 50%, no more than 70%) throughout the pool hall area.
Ventilation systems are designed and operated to provide a level of fresh air for each occupant of the pool hall (bathers, staff and spectators).
Nb include the relevant clauses of PWTAG CoP sections 3 to 14
8.1 Faecal accidents and Cryptosporidium
This pool has a written agreed procedure for dealing with faecal fouling which follows the guidance on the PWTAG website and in the Code of Practice.
8.2 Blood and vomit pool water contamination
If significant amounts of blood are spilled into the pool, it is temporarily cleared of people, to allow the pollution to disperse and any infective particles to be neutralised by the residual disinfectant. We then confirm that disinfectant residuals and pH values are within the recommended ranges and bathing can then resume.
8.3 Contamination of pool surround
Any blood spillage on the poolside is dealt with using strong disinfectant - of a concentration equivalent to 10,000mg/l of available chlorine. The blood is covered with paper towels, gently flooded with the disinfectant and left for at least two minutes before it is cleared away.
8.4 Vomit in the pool
Our procedures for vomit in the pool and vomit on the poolside are the same as when dealing with blood.
8.5 Pool closure and Microbiological contamination
We close the pool immediately if there is chemical or physical evidence of unsatisfactory disinfection eg poor clarity or low free chlorine concentration.
The pool is closed if microbiological testing indicates gross contamination, which means one of two things:
1 E. coli over 10 per 10 ml PLUS either colony count over 10 cfu per ml or Pseudomonas aeruginosa over 10 per 100ml (or, of course, both)
8.6 Toxic gas leaks
There is an emergency action plan for dealing with any major release of toxic gas.
The procedure includes Safety of staff and customers arrangements for any necessary evacuation.
co-ordination with emergency services, who are consulted in the preparation of this plan.
[new requirements to come from BS EN 15288]
The pool water is first de-chlorinated using sodium thiosulphate pentahydrate or equivalent.
1 Any ozone treatment plant or carbon filters are bypassed (and the flow rate restored to what it was before the bypass) other filters not bypassed should be clean.
2 There are a number of different dyes used, and the precise nature of the test will be affected by that choice. Eriochrome black T (solochrome) is used dosed at 0.2g/m3 of pool water potassium permanganate is dosed at 0.3g/m3 (UV as well as ozone treatment plant should be bypassed if permanganate is used). The dye is dosed for 5-10 minutes. It is added to the pool close to the chlorine dosing point, usually through a chemical dosing pump or strainer box.
3 The time taken for the pool water to become evenly coloured gives a first measure of the adequacy of the distribution system. This should be achieved within 15 minutes for the result to be satisfactory.
4 Once the colouration of the pool is completed, the dye should be removed without delay using chlorine, ozone or equivalent. As well as avoiding any staining, this addition initiates the second part of the test. 5mg/l of chlorine should clear the dye colour in 15 minutes to confirm the test result.
1 A hair probe is made of 50g of natural or of a good quality synthetic, both medium to fine, straight, 400mm in free length. The hair probe shall be in good condition tangle free and the end of single strand may not be jagged.
2 One side of hair probe is attached to a rod of 25 to 30mm diameter. The rod should be at least 300mm long.
3 A dynamometer with an accuracy of 0.5N, to determine the traction force against the entanglement, is needed.
4 For the on-site test, the pool has to be in full operation. The test may be carried out from basin edge, water surface or by diving or robotic equipment.
5 Saturate the hair for at least 2min in pool water. After being saturated, place the free end of the hair approximately 300mm in front of the device and above the uppermost surface of the face of the device
6 Slowly move the hair ends closer to the device and feed the highest possible quantity of hair ends into the device itself in the direction of the intake flow. Continue to feed the hair slowly by moving the rod from side to side while shortening each pass for at least 60 seconds until ideally at least 50% of the length has been sucked in. In any case a length suitable to detect the presents of turbulence behind the grille has to be fed in. Then lay the rest of the hair against the device, in such a way that the hair remains in contact with it for at least 30 seconds.
7 The surface of the device is divided into areas of about 50 x 50cm. In the centre of each area and additionally above the pipe, where the water speeds is highest, one test is done. If the hair does not get sucked into the sump the test is passed. With the pump still operating, test the pulling force necessary to free the hair from the device. Measure the force of entanglement.
8 Repeat the test three times for each area. For devices with perforated plates, grilles (eg with a larger surface) move the free end of the hair over and against the whole surface. Detect if the hair probe gets sucked.
9 If one device serves more than one attraction, the test is done at the maximum of the possible flow rate.
10 Brush hair periodically, to keep tangle-free.
First published November 2012 – PWTAG CoP 11.12 First revision Jan 2013 PWTAG CoP 1.13
18.104.22.168 Disposal of hygiene waste
10.8 Balance tanks - Annual inspection and cleaning as necessary 11.1 North light or lighting cabinet for comparator
11.3.3 Depth of taking sample to 100-300mm
12.1.3 Samples taken according to BS EN ISO 19458
15.2.2 Disinfectant dosing post ozone/uv
15.2.5 CAS and EINECS numbers to include on precaution cards 15.9.2 Risk assessment for manual handling of chemical containers
2nd revision November 2013-10-28 11.4 Free chlorine levels
11.4.1 For all pools using hypochlorites, assuming the pH value is 7.2, the free chlorine levels should be maintained at 1mg/l or below, to an absolute minimum of 0.5mg/l. The use of ozone or UV (see 5.7) can help minimise the required free chlorine levels. These values can be achieved only where the pool is designed and engineered and operated well with effective pre-swim hygiene and not overloaded.
11.4.2 These values - indeed, any values - require validation by satisfactory bacteriological water quality standards.
11.4.3 Free chlorine levels above 3mg/l should not be necessary in any pool. If this is exceeded, dosing should be reduced.
11.4.4 If dosing has gone wrong and free chlorine exceeds 5mg/l, chlorination should be stopped immediately; above 10mg/l bathing should cease.
11.4.5 For pool using chlorinated isocyanurates as disinfectant, free chlorine should be maintained at 2.5-5mg/l and the cyanuric acid at 50-100mg/l.
3rd revision PWTAG CoP 04.14 April 2014-04-01
22.214.171.124 The pool hydraulics should ensure appropriate turnover periods and good mixing of water in the pool; short circuits and deadlegs should be avoided
7.3 Backwashing protocol is critical; when neglected, for example, it can be a factor in outbreaks of cryptosporidiosis
7.4.1 Coagulation - This procedure significantly reduces the risk associated with any unseen faecal release
8.1.1 Control entry
9.0 Section on Faecal fouling is replaced with sections of technical note 2 Faecal contamination for pools with medium rate filtration
4th revision September 2014
V4 - Update created: 19/4/2017
1.2) Infection – ‘legionella’ removed – replaced with "various bacteria and viruses causing gastroenteritis and Pseudomonas aeruginosa”
1.3) Typeface - changed to Arial
1.8) Spa Pool guidance updated from HSG274 part 4 to – HSG282
PWTAG Code of Practice for Swimming Pool Water - Updated to reflect the requirements of Managing Health and Safety in Swimming Pools (HSG179)
April 4, 2017 – V4