Active IQ Level 3 Award in Managing Pool Operations (sample manual)

Manual
Level 3 Award in
Managing Pool
Operations
Version AIQ005800

The principles and practice
of pool water treatment
and testing
Aim
This unit provides an overview of the responsibilities held by pool operators to ensure the environment is safe for
staff and visitors. The different types of pool that operators may come across are discussed, along with the various
models of pool ownership and recommended temperatures for these different types. An understanding of the
importance of good cleanliness and hygiene is essential for a pool operator, as well as knowing the causes of water
pollution and how a pool’s water circulation system works to keep that pollution to a minimum.
A key responsibility of pool operators is that they know how to test pool water, and so a further focus of this unit
is the tests used to ensure optimum pool water quality, how to carry out the tests properly, and to understand the
importance of accurate record keeping.
Learning outcomes
At the end of this unit you will:
• Understand the legal responsibilities of pool operators to provide a safe pool environment
• Understand the types of pools and pool ownership
• Understand the causes of pool water pollution and contamination
• Understand the importance of good bather hygiene prior to the use of pools
• Understand the importance of good standards of cleanliness in the swimming pool environment
• Understand the operating principles of a simple pool water circulation system
• Know the recommended temperatures for the types of pools used in active leisure facilities
• Understand how pool operators provide a safe pool environment
• Know the essential tests to ensure optimum pool water quality
• Understand the different types of pool water testing equipment
needed to ensure good quality pool water
• Demonstrate correct pool water testing techniques
• Understand the importance of accurate record keeping
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1

The pool water circulation system
Section 6
Section 6: The pool water
circulation system
In order for swimming pool water to stay safe and clear, it needs to flow through a series of processes (see figure 6.1).
Figure 6.1 Schematic pool circulation (hypochlorite disinfectant: no UV)
ACID INJECTION
POINT
POOL
BALANCE
TANK
HEAT EXCHANGER
(CALORIFIER)
SIGHT GLASS
TO DRAIN
HYPOCHLORITE INJECTION
POINT
FILTER
FILTER
TO DRAIN
COAGULANT/
FLOCCULANT
INJECTION
POINT
BACK WASH
FLOW METER
SIGHT GLASS
STRAINER
CIRCULATING
PUMPS
SAMPLE POINT
TO DOSING UNIT
A surface draw-off system removes the surface water, and
water leaves the bottom of the pool through sump outlets.
In deck level pools, the water is then fed into a balance tank.
The balance tank (figure 6.2) accommodates the water
displaced by bathers. The balance tank also provides
a means of introducing water into the system to replace
water used to wash the filters.
The principles and practice of pool water treatment and testing
Figure 6.2 A balance tank
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Section 9
The essential tests to ensure optimum pool water quality
The comparator
The traditional method of pool water testing for pH and chlorine uses a comparator. This is a very simple piece
of equipment where the test sample containing the reagent dye is compared against a circular disc of different
coloured pieces of glass.
Ideally, the comparator should be fitted with a portable back-light which provides good quality white light to
accentuate the colours, or it should be viewed against a bench-mounted white light source.
Figure 9.2 A comparator
The comparator should be used with the disc appropriate to the test being carried out: a pH disc (phenol red), a
chlorine disc or a disc which measures bromine levels.
If the comparator is viewed against a white light source, a more accurate result will be given.
Figure 9.3 Chlorine, pH and bromine discs
Using a comparator to measure pH
1
Select
2
Add
3
Take
4
Insert
5
Revolve
the phenol red disc and insert it into the comparator. Ensure it is installed the correct
way, with the numbers in the right hand corner of the comparator.
a 10ml sample of water to the left hand test tube.
a second clean test tube containing 10ml of water and crush a phenol red tablet into it.
the test tube containing the phenol red dye into the right hand side of the comparator.
the comparator disc until the colours match. The reading can be found in the bottom
right hand window of the comparator.
36
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Valves commonly used in the swimming pool plant
Section 4
Section 4: Valves commonly
used in the swimming pool
plant
There are a number of different types of valves used within the pool plant. The type of valve employed will largely
depend upon the age of the pool and whether the pipework is plastic or steel.
Gate valves
In older pools, the traditional type of valve used is the gate valve. Because of the
nature of its construction, a gate valve cannot be opened and closed too quickly.
Figure 4.1 Gate valve
Figure 4.2 Butterfly valve
Figure 4.3 Ball valve
Figure 4.4 Non-return
or check valve
The operator turns the handle on the wheel clockwise (to the right) in order to close
the valve and anticlockwise (to the left) in order to open the valve. As the wheel is
turned, a gate within the valve lowers and closes off the flow through the valve.
Butterfly valves
In newer installations, a butterfly valve tends to be employed. These can be manually
operated, pneumatically operated or driven by a motor.
The commonest version of the valve is the manually operated type, and this works
by moving the valve handle. If the handle remains in line with the axis of the pipe,
this indicates that the valve is open, whereas if the handle lies across the pipe (i.e.
90° to the axis of the pipework), this indicates that the valve is closed.
The pool operator must always open and close this valve slowly to avoid hydraulic
shock.
Ball valves
Ball valves are used in installations where the pipework is plastic or PVC.
Ball valves operate in a very similar way to butterfly valves, but instead of there
being a disc within the valve which opens and closes the orifice, there is a plastic
ball.
Once again, if the handle is in line with the axis of the pipe, the valve is open and
vice versa.
Non-return or check valves
This type of valve is employed where the pool water circulation pump is located
above the pool water level. The purpose of the valve is to stop fluid flowing in the
wrong direction, and in its simplest form, the valve contains a hinged flap which
freely swings open when the fluid goes in the right direction, but clangs shut if the
fluid begins to run back on itself. For this reason, it is sometimes referred to as a
‘flap’ or check valve.
A check valve is also incorporated into injection points and in the suction points
from chemical dosing systems.
The principles of pool plant operations and chemical safety
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The risks involved in the storage and use of chemicals for the treatment of pool water
Section 7
It is an internationally agreed-upon system designed to replace the various classification and labelling standards
used in different countries, with consistent criteria for classification and labelling on a global level.
The European Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures
came into force on 20th January 2009 in all EU Member States, including the UK. It is known by its abbreviated
form, ‘the CLP Regulation’ or just ‘CLP’.
Examples of CLP compliant signs are shown in figure 7.2.
Sign
Explanation/guidance
Flammable if exposed to ignition sources, sparks or heat. Some substances with this
symbol may give off flammable gases in contact with water.
• Avoid ignition sources (sparks, flames, heat)
• Keep your distance
• Wear protective clothing
Can burn even without air, or can intensify fire in combustible materials.
• Avoid ignition sources (sparks, flames, heat)
• Keep your distance
• Wear protective clothing
Contains gas under pressure. Gas released may be very cold. Gas container may explode if
heated.
• Do not heat containers
• Avoid contact with skin and eyes
Corrosive material which may cause skin burns and permanent eye damage. May corrode
metals.
• Avoid contact with skin and eyes
• Do not breathe vapours or sprays
• Wear protective clothing
• Keep away from metals
The principles of pool plant operations and chemical safety
Toxic material which may cause life-threatening effects even in small amounts and with
short exposure.
• Do not swallow the material, allow it to come into contact with skin or breathe it
Figure 7.2 CLP compliant signs (continued on next page)
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The processes involved in the operation and treatment of spa pools and hot tubs
Section 9
Hot tubs
Hot tubs are self-contained units, usually fitted with cartridge filters and chemically hand-dosed, although some do
have floating dispensers and some also have chemical feeders.
Since they are often found in holiday parks and in private apartments, supervision is an issue and users must be
provided with guidance on their use.
Limitations to spa pool and hot tub use
The use of spa pools and hot tubs is not recommended for people affected by the following:
• Pregnancy
• Heart/circulatory problems
• Open/infected wounds
• The influence of drugs
If there is any doubt, medical advice should be sought.
• The influence of drink
• Food eaten within 1½ hours
• Young children
Test Range Maximum/concerns
Free chlorine 3.0–5.0mg/l 10.0mg/l
Combined chlorine 1mg/l (review control measures)
pH (based on chlorine) 7.0–7.6 7.6
Total bromine 4.0–6.0mg/l 12.0mg/l (or >10.0mg/l SPW)
TDS
Other tests values from SPW
No more than 1000mg/l
higher than the incoming
fill water
Total alkalinity 80–200mg/l 200
>1000mg/l higher than the incoming fill water
(Review control measures. Spa pool will need to be
emptied and refilled to lower concentration.)
Calcium hardness 80–200mg/l

The importance of providing a safe and effective pool water disinfection system
Section 2
As can be seen from figure 2.1, at a pH of approximately 7.0 in a chlorine pool, the percentage of active disinfectant
(based on HOCl) is 62%. However, this drops to 22% at pH 8.0.
It can also be seen that at a pH of 8.0 in a bromine pool, the percentage of active disinfectant (based on HOBr) is 82%.
The Traffic Light System (RAG Rating)
Some pool operators have found it helpful to interpret the pool water readings based on a traffic light rating system.
The pool readings will fall within the Green, Amber or Red Zone i.e. a RAG rating. The pool operator must first
determine the appropriate chlorine levels which fit within the various zones by catting out a risk assessment.
The interpretation is as follows:
Green Zone:
The pool operator should always strive to keep all values within the green zone. These results
are within the acceptable range and no corrective action is necessary. For example, the
results would be in this zone if the free chlorine level was between 1.0mg/l - 2.5mg/l and the
pH value was between 7.2–7.4, as they may be in the case of a typical swimming pool.
Amber Zone:
Red Zone:
These results are allowable, but not ideal, and so corrective action needs to take place to
ensure that the result returns to the green zone.
If the reading falls within the amber zone for chlorine levels and pH, for example, if the free
chlorine level was between 0.6mg/l–1.0mg/l or between 2.6mg/l–5.0mg/l, and the pH
value was between 7.0–7.1, or 7.5–7.9, then corrective action need to be taken and the
tests repeated within 30 minutes. If the reading is still in the amber zone, then immediate
corrective action is required. If the results fail to return to the green zone, this could lead to
the situation entering the red zone and closure of the pool.
These results are no longer within an acceptable range. The pool should be closed and
corrective action should be taken. The pool should not be re-opened until the results are at
least within the amber zone.
Typical red zone results would be where the free chlorine level was less than 0.5mg/l or above 5.0mg/l, or when the
pH value was below 7.0 or above 8.0. between 7.0–7.1, or 7.5–7.9.
ACTIVITY
This activity will help to consolidate your understanding of free chlorine, combined chlorine and the link
with pH.
The following chart shows chlorine levels and pH values from a series of pools.
1. Workout the combined chlorine readings and enter them in the table.
The management of pool water quality
2. Make comments about how well these readings match up with what could be considered as best
industry standards.
3. Which of the readings would be considered Green in the RAG rating system in your pool?
4. Which of the readings would be considered Red in the RAG rating systemin your pool?
5. Which of the readings would be considered Amber in the RAG rating system in your pool?
No Time Free
chlorine
Comb.
chlorine
Total
chlorine
1 0700 2.50 3.50 7.8
2 0700 5.00 6.00 7.8
3 1300 0.40 2.00 7.5
4 2300 1.00 3.00 7.4
5 0700 1.00 1.30 7.3
6 0700 1.60 2.00 7.2
7 0700 1.00 1.40 7.2
8 0700 10.00 12.00 8.0
9 0700 0.90 1.20 7.2
10 0700 2.00 3.50 7.8
pH
Comments
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