SWIMMING POOL WATER - THE ESSENTIAL GUIDE

Swimming Pool Technical Operator (SPTO)

People studying for PWTAG-approved Swimming Pool Technical Operator (SPTO) qualification should be taught the following:

What is a pool?

Types of pool and uses

Types of pool tank and finish

How swimming pools work – the recirculation cycle:

  • circulation system
  • filtration
  • chemical disinfection
Pollution and Hygiene

Pollution from bathers – why people are the main source of pollution bathers:

  • skin scales, sweat, urine, mucus from the nose and chest, saliva, hair, faecal matter, cosmetics, suntan lotion

Pollution not from bathers:

  • indoor and outdoor pools, dust, floating debris, grass, dirt (soil/stones) precipitated chemicals, sand from filters, byproducts of chemical treatment

Pre-swim hygiene:

  • toilets and showers – the value of pre-swim hygiene

When not to swim – exclusion policies

Babies and toddlers – swim nappies

Management, regulation and training

Staffing structure and management systems – their impact on water quality

Health and Safety – the legal requirements

HSG 179 – the written procedures (PSOP and method statement)

COSHH – substances hazardous to health in a pool, chemicals and microorganisms

Confined spaces – and its application

O&M manual and schematic drawing

Training – who, when and how much is needed

PWTAG Code of Practice – Swimming Pool Technical Operations’ role in written procedures

Design

Design issues impacting on water quality

Awareness of BS EN 15288 1 & 2, the design, management and operation of swimming pools

Sport England design guide

Changing rooms:

  • toilets and showers
  • baby changing facilities
  • floors in wet areas

Safe access – including people with disabilities

The plant room – location, size and access

Chemical store

Temperature and humidity

Energy management

Hydraulics and water circulation

Bather load – calculating the factors for safety and water quality

Circulation rate – calculations

Turnover period – calculations and alignment with PWTAG standards

Hydraulic design – different design solutions

Surface water removal – focusing on removing pollution:

  • deck-level
  • channels
  • skimmers

Balance tanks – purpose, design and maintenance

Outlet and inlet safety – the entrapment: PWTAG Code, BS EN 13451–1 and 3

Moveable floors and booms – effects on hydraulics and water quality

Circulation pumps – the principles, variable speed drives

Valves – types, uses and safe operation

Flow meters and pressure gauges – calibration, maintenance

More than one pool – separate treatment systems

Dye testing – why and when

Filtration

Clarity of water – importance

Filtration rates – pros and cons:

  • medium-rate
  • high-rate

The sand bed – grades and depths

Underdrains – how they work, how they are best constructed

Other types of filter:

  • bags and cartridges
  • pre-coat
  • carbon
  • glass
  • membrane
  • zeolite

Backwashing – the principles:

  • how to backwash, fluidisation of the bed, air scour, the rinse cycle
  • strainer basket – part of the process
  • when to backwash – PWTAG Code and guidance

Filter design – materials, sizes and fittings Filter maintenance – the annual programme

Coagulation – what it is

  • how it works – agglomeration and flocculation
  • high-rate filters – and coagulants

Coagulants:

  • dosing – quantities and rates
  • injection – where to apply
Primary disinfection

Suitability and compatibility of disinfection types

What is disinfection – in a swimming pool setting

Oxidation – what it is, and does

CT rates – an appreciation

Choosing a primary disinfectant – chlorine, hypochlorite, chlorinated isocyanurates, bromine (soft water, hard water, costs and impurities)

The chemistry of chlorine disinfection – an understanding:

  • how chlorine forms a residual – hypochlorous acid and hypochlorite ion
  • the effects of pH on disinfection – the values to pursue and why
  • breakpoint chlorination – understanding the crucial role of breakpoint
  • chlorine plus ammonia – urea, chloramines
  • nitrogen trichloride – its causes
  • organic chloramines – how they are caused, their effects and removal

Free and combined chlorine – the relationship and target levels

pH value – its influence on disinfection and the options

Electrolytic generation of chlorine – the systems and applicability

Chlorinated isocyanurates – when and how to use:

  • cyanuric acid – awareness of influence of residuals; outdoor pools
  • residual values – PWTAG guidance

Bromine based disinfectants BCDMH – what it is and the residuals:

  • sodium bromide

Other forms of residual disinfection and new treatments

The importance of dilution – why disinfection and filtration is not enough

Secondary disinfection

When secondary disinfection should be considered

The effects of secondary disinfection

Dealing with Cryptosporidium

Ozone – what it is, how it is applied, the pros and cons

UV – what it is, how it is applied, maintenance and monitoring, pros and cons

Dosing chemicals

Principles – key requirements when dosing chemicals

Components – the system design and infrastructure

Dosing practice – where, when and how

Hand dosing in emergencies

Diluting chemicals – how and when to dilute

Dissolving dry chemicals

Dose strength – calculations

Day tanks – use, construction and fittings

Dosing pumps – type, construction and capacity

Pipework – construction and application

Valves and fittings – that may be incorporated into the dosing system

Calibration – checking the dosing rate

Faults – fail safe systems

Automatic control – optimising dosing treatment:

  • closed loop – how the control works
  • sample mixing – representative sample
  • sampling – where to sample from
  • calibration – independent analysis of the sensor to verify the desired effect
  • sensors – amperometric, redox, pH value
  • controllers – the levels of sophistication

Circulation feeders – what they are and how they work:

  • trichlorinators
  • brominators
  • calcium hypochlorite

CO2 installation and dosing requirements

Super-chlorination

Pool water chemistry

Source water quality

Alkalinity – the effect on pH

Hardness – PWTAG guidelines, grout and scale

Dissolved solids – Corrosion, erosion and PWTAG guidelines

Water balance – what it is

Disinfection by-products – the health effects:

  • nitrogen trichloride – effects, monitoring and mitigation
  • THMs – role of humic acid, monitoring and removal
Testing and controlling pool water chemistry

Comparator and photometer – how to use them

How to sample and test for:

  • free chlorine
  • combined chlorine
  • pH

Chlorine disinfection:

  • testing frequency
  • disinfectant residual tests – PWTAG Code and standards
  • understanding effects of free chlorine on chloramines
  • interpreting test results
  • acting on chlorine residual results
  • monitoring

pH value – measuring and checking:

  • alkaline disinfectants – effect on pH
  • acidic disinfectants – effects on pH

Alkalinity

Hardness

Dissolved solids – measuring and control

Langelier and water balance – measuring and control – in context

Documentation and record keeping and storing test results

Bromides:

  • measuring and control
  • interpreting and results

Documentation

Healthy swimming – the health risks

Infectious hazards, including transmission:

  • gastro-intestinal infections – Shigella, Escherichi coli, Cryptosporidium
  • foot infections – verruca and athletes foot
  • skin infections – molluscum contagiosum, Staphylococcus aureus and MRSA
  • eye infections – including Acanthamoeba

Non-infectious hazards:

  • respiratory irritation – including Legionella and asthma
  • skin irritation – bromine, Pseudomonas aeruginosa, folliculitis
  • ear infections, including otitis externa
Preventing Outbreaks

What goes wrong – definition of an outbreak

Problems that have lead to outbreaks

Dealing with a faecal incident – The PWTAG Code, technical note and NHS UK Cryptosporidium Reference Unit: Guidance for Investigators and Health Professionals:

  • solid faeces
  • runny faeces
  • procedure for medium-rate filters
  • procedure for high-rate filters
  • prevention
  • blood and vomit
Microbiological testing

Sampling – must include chemical tests

Aerobic colony counts (TVC)

Coliform and E coli – potential faecal or environmental pollution

Pseudomonas aeruginosa – the reasons for testing

Legionella – testing for spas, showers and water storage

Test requirements – monthly analysis

Interpreting results – assessing microbiological quality,

Remedial action

Gross contamination and closure of the pool

Quality assurance

Pool chemical safety

Material safety data sheets – provision and use

Risk and COSHH assessment – the process and elimination

Delivery:

  • access
  • unloading

Bulk deliveries and storage

Transporting chemicals

The chemical store

  • siting
  • fire risk
  • spillage
  • ventilation

Storage of disinfectants and other chemicals including:

  • sodium hypochlorite
  • calcium hypochlorite
  • BCDMH
  • chlorinated isocyanurates
  • sodium bisulphate
  • CO2
  • hydrochloric acid
  • sulphuric acid
Plant maintenance

Servicing and frequency

Calibration

Daily monitoring and maintenance, fault finding

Cleaning and hygiene

Floor surfaces – dirt, slips trips and falls and bacteria

Around the pool – PWTAG technical note

Scale removal

Pool covers – cleaning both sides to control mould and Pseudomonas aeruginosa

Transfer channels and balance tanks – regular maintenance

The pool bottom – particularly deck-level pools

Moveable floors and booms – the need to clean under structures

Stainless steel – preventing corrosion

Inflatables and swimming aids – prevention of Pseudomonas aeruginosa

Safeguarding the fabric of the building – preventing steel corrosion cracking, pool grout, filling and emptying pools

Algae

PPE and plant room emergency procedures

The regulations – assessment, provision and use

Harmful effects – the potential risks to health from chemical exposure

PPE – what to use and when, use of MSDS

In an emergency – what to do for chemical contact/inhalation/ingestion

Emergency showers and eye baths

Toxic gasses, fires and explosions

Spillages – PWTAG Code and technical guidance (sodium hypochlorite)

PWTAG Code and emergency procedures – chemicals emergency part of the EAP

Spa pools

Commercial spas – definition and comparison with domestic

Basics – loading, turnover, filtration, and dilution

Hydraulics – water flow and air flow

Inlets and outlets – the risks from booster pumps

Disinfection – types, levels, dosing and monitoring

Microbiological testing – regulations, Pseudomonas aeruginosa, Legionella

HPA/HSE guidance

Theory Assessment Exam

A wholly written exam shall at a minimum cover a fair representation of the essential topics as outlined in the theory element of the syllabus above.

The Swimming Pool Technical Operator Practical

There are four basic areas of practical ability that can be taught in any suitable location, and should then be assessed in the student’s workplace, as part of the exam.

Doing a full set of water tests for swimming pool water

This should include:

  • free chlorine
  • total chlorine
  • pH
  • total alkalinity
  • calcium hardness
  • total dissolved solids (TDS).
Drawing a schematic diagram of the layout of a swimming pool plant

This should indicate clearly (using arrows to indicate the direction of flow) each of the main components, including:

  • filters
  • pumps
  • strainers
  • automatic dosing units
  • monitoring equipment
  • main valves.
Demonstrate how to backwash the filtration system

This should be of a chosen pool, in accordance with normal operating procedures. It should include an explanation of why and when this must be carried out.

Making a risk assessment for one pool chemical

This should refer to a chemical stored in the plant room of a chosen swimming pool. It should include identifying the requirements for storage, handling and use of the chemical.

Practical Assessment

Documentation of these tasks shall be provided to the pool manager, who must sign them off to show that they are based upon the pool used in the assignment.

The PWTAG Approved Trainer course organiser will assess the evidence presented and determine if the student has demonstrated sufficient knowledge and practical skills and provide this as part of the assessment record.

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