Policy For the Management and Control of Legionellosis
UK Dental
Policy for the Management &
Control of Legionellosis for
Dental Practice
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This Policy and Procedure Manual has been written by Haydn Harris MCIPHE MWMSoc and
is intended for free distribution within the Dental community.
The content of this policy has not been designed for any single Dental Practice and must be
arranged by the person responsible for the premises to suit their needs. This will involve
completing/changing text in red with the relevant details. The Author accepts no
responsibilty or liability in any way for any consequence/loss resulting from the content or
action of the contents of this document.
Haydn Harris may be contacted following the details in the Management
Team and Contacts Section 5 of this Document.
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UK Dental
CONTENTS
1)
Introduction
2)
Legislation/Regulations
3)
Risk Assessment
4)
Management Responsibilities
5)
Management Team and Contacts
6)
Policy – Control of Legionellosis
7)
Managing and Controlling Legionellosis
8)
Systems Design and Considerations
9)
Pre Planned Maintenance
10) Measured Parameters Recommended Limits
11) Pre Planned Maintenance Task Specifications
12) Record Keeping
13) Policy Maintenance Review
14) Elevated Sample Procedure and Outbreak Procedure
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UK Dental
INTRODUCTION AND POLICY STATEMENT
This document is intended to provide a Scheme of Precautions for the Management
and Control of Legionellosis for DENTIST.
It is the responsibility of DENTIST, hereinafter known as The Practice; under the
Health and Safety at Work Act 1974 etc. (Section 16) and the Control of Substances
Hazardous to Health 2002, to take all reasonable precautions and to follow approved
codes of practice for managing and controlling risks.
The guidance issued for the control of Legionella Bacteria in Water Systems is for
most circumstances, ‘The Approved Code of Practice L8 – The Control of Legionella
Bacteria in Water Systems (‘ACoP L8’ hereinafter)’ and also for NHS Trusts in England
and Wales HTM 04-01 and HTM 00-05 Decontamination of Dental Equipment.
The Practice accepts its responsibility for the Management and Control of
Legionellosis including Legionnaires Disease under The Health and Safety at Work Act
1974 (section 16) and the Control of Substances Hazardous to Health 2002 and ‘ACoP
L8’.
This Policy sets out the control measures and the Management Systems utilised by
The Practice (known also as the written Scheme of Precautions), to Manage and
Control the risk of Legionellosis and Legionnaires Disease and complies with the
‘ACoP L8’.
This document forms the ‘written Scheme of Precautions’ detailed in ‘ACoP L8 Part 1
paragraph 52 and 53:
‘52 Where the Assessment shows that there is a reasonably foreseeable risk, the use
of the water systems, parts of the water systems or systems of work that lead to
exposure has to be avoided so as far as reasonable practicable.’
‘53 Where this is not reasonably practicable, there should be a written scheme for
controlling the risk from exposure which should be implemented and properly
managed.’
The aim of this Policy is to provide for The Practice’s employees, a structured
approach for the Management and Control of Legionellosis including Legionnaires
Disease, detailing all the requirements of The Practice to comply with the ‘ACoP L8’,
HTM 00-05 and HTM 04-01.
As laid down in The Health and Safety Commission's Approved Code of Practice L8 –
to comply, The Practice will undertake to:
a) Identify and assess sources of risk
b) Prepare a scheme for preventing, reducing or controlling the risk
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c) Implement and manage precautions
d) Keep records of the precautions implemented
e) Appoint a person to be managerially responsible
The scope of the Policy extends to all of the properties currently owned or occupied
by The Practice and those properties that may come into ownership or occupation of
The Practice.
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LEGISLATION / REGULATION
The Practice will utilise the following guidance and Approved Code of Practice to
manage the associated risks within its premises:
a)
The Control of Legionella bacteria in water systems – Approved Code of
Practice & Guidance L8 (2001).
b)
Health and Safety at Work etc. Act 1974, Sections 2, 3 and 4.
c)
Health Technical Memorandum 04-01 and 01-05.
d)
Control of Substances Hazardous to Health Regulations 2002, Regulation 6.
e)
The Public Health (Infectious Diseases) Regulations 1988.
f)
The Water Supply (Water fittings) Regulations 1999.
g)
BS 6700:2006 - Specification for Design, installation, testing and maintenance
of services supplying water for domestic use within buildings and their
curtilages.
h)
Food Act 1990.
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The Control of Legionella bacteria in water systems – Approved Code of Practice &
Guidance L8 (ACoP L8)
This Approved Code of Practice gives practical advice on the requirements of the
Health & Safety at Work etc. Act 1974 in particular sections 2, 3, 4 and 6 (as
amended by the Consumer Protection Act 1987) and regulations 6, 7, 8, 9 and 12 of
the Control of Substances Hazardous to Health Regulations 1999 (2002).
The ACoP L8 has been approved on the 23rd November 1999 by the Health and
Safety Commission and came into effect on the 8th January 2001 and superseded
‘The prevention and control of Legionellosis (including Legionnaires Disease) (L8rev)’
and is designed to give advice on how to comply with the Law.
‘Only the Courts can give an authoritative interpretation of the law in considering the
application of these regulations and guidance working under another’s direction’
‘The Management of the Health and Safety at Work Regulations provide a broad
framework for controlling health and safety at work. As well as requiring Risk
Assessments, they also require access to competent help in applying the provisions of
the health and safety law’
The main obligations under the ACoP L8 are to:





Appoint a Managerially Responsible Person
Undertake Risk Assessments
Devise a Scheme of Precautions
Implement that Scheme of Precautions
Keep sufficient records
Health and Safety at Work etc. Act 1974
Under the 1974 Act, it is the general duty of every employer to ensure, so far as is
reasonably practicable, the health, safety and welfare at work of all his employees.
In particular, so far as is reasonably practicable, the employer has to provide a safe
system of work; make arrangements for ensuring safety and absence of risk to health
connected with the use, handling, storage and transport of articles and substances;
provide information, instruction, training and supervision necessary to ensure health
and safety at work; provide safe access to and from the workplace; and provide a
working environment that is safe, without risk to health, and adequate as regards
facilities and arrangements for welfare at work.
As laid out in the ACoP L8, duties under the HSWA extend to risks arising from
Legionella bacteria which may arise from work activities. Such duties are legally
enforceable and the Health and Safety Executive hold responsibility for enforcement
of the law.
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Responsibilities fall upon both owners and occupiers of premises, to ensure that
there is a management regime for the preparation, design, installation and
maintenance of plant, equipment and systems.
HTM 04-00 and HTM 01-05
Health Technical Memorandum 04-01 The control of Legionella etc provided
practical advice and guidance to controllers of healthcare premises.
In its nature it is similar to the Approved Code of Practice L8 and the requirements
remain the same.
The HTM comprises of 2 parts A – Design, installation and testing and part B –
Operational Management.
It is important that important the all users are familiar with both parts of the
guidance to assist with its implementation.
Heath Technical Memorandum 01-05 Decontamination in primary care dental
practices sets out a number of requirements for Legionella control.
For dental unit water lines DUWLs a basic requirements is as follows:
General requirements:
The unit supplies made directly from the incoming main must be made using
adequate backflow prevention.
The water lines (including spittoon and any spare hand tool that may not be used
regularly) must be flushed through for 2 minutes prior to the first use of the day, for
20 – 30 seconds between patients, for 2 minutes following lunch breaks and at the
end of the working day.
The DUWLs must be maintained in a clean condition free from biofilm, this is usually
achieved using a sterilising solution which controls and eliminates biofilms. Refer to
any dental unit manufacturers instructions for specific controls/sterilising products.
The spittoon water jet nozzles must be maintained clean and free from scale.
The water used for filling the removable bottled must not be filled directly from the
incoming main but filled from treated water.
The removable bottle serving the tools must be removed and left inverted at the end
of each day and allowed to dry.
Where the unit has both mains and bottled supplies, both must be flushed through
by operating the integral switch of the unit.
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Control of Substances Hazardous to Health Regulations 2002, Regulation 6
(COSHH).
The 2002 COSHH regulation includes exposure to biological agents if they are directly
connected to the workplace. Only biological agents that are beyond the control of an
employer (such as catching an infection from a workmate) are not covered under
COSHH.
The requirements of COSHH are to:
1) Assess the risk of exposure
2) Decide what precautions are needed
3) Prevent or adequately control the exposure
4) Ensure that control measures are used and maintained
5) Prepare plans and procedures to deal with accidents incidents and
emergencies
These regulations also apply to the chemicals which may be used to control the
growth of organisms in water supply.
The Public Health (Infectious Diseases) Regulations 1988.
This regulation requires that a ‘proper Officer’ shall inform the Chief Medical Officer
of any serious outbreak of any disease which has, to his knowledge occurred in his
district. This includes Legionnaires Disease.
‘a proper Officer shall, if his district or port health district is in England immediately
inform the Chief Medical Officer for England, or, if his district or port health district is
in Wales immediately inform the Chief Medical Officer for Wales of—
(a) Any case or suspected case of a disease subject to the International Health
Regulations and
(b) any serious outbreak of any disease (including food poisoning)which to his
knowledge has occurred in his district or port health district, and he shall similarly
inform the appropriate Medical Officer of the appropriate District Health Authority.’
The Water Supply (Water Fittings) Regulations 1999
These regulations came into force on the 1st July 1999 and apply in detail the supply
and design of water fittings and the application of the water fittings within a
property owned or occupied by an employer.
These regulations should be utilised as a guide for employers undertaking upgrading
or replacing of water services within their properties and for new build projects.
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BS 6700:2006 Specification for Design, installation, testing and maintenance of
services supplying water for domestic use within buildings and their curtilages.
This standard specifies the requirements for and gives recommendations on the
design, installation, alteration, testing and maintenance of services supplying water
for domestic use within buildings and their curtilages. It covers the system of pipes,
fittings and connected appliances installed to supply any building, whether domestic
or not, with water for drinking, culinary, domestic laundry, ablutionary, cleaning and
sanitary purposes.
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RISK ASSESSMENT
As recommended in the ACoP L8 section 23;
‘A suitable and sufficient assessment is required to identify and assess the risk of
exposure to Legionella bacteria from work activities and on the premises and any
necessary precautionary measures.’
Risk Assessments are also a requirement of the ‘Control of Substances Hazardous to
Health 2002’ Section 6 and ‘The Management of Health and Safety at Work
Regulations 1999’ Regulation 3 and ‘The Health and Safety at Work etc. Act 1974’
Sections 2, 3 and 4.
A Risk Assessment will be undertaken by or on behalf of The Practice by a suitably
trained and competent person and will include all of the properties currently
occupied and owned by The Practice and provision allowed for the Risk Assessment
of Properties that become occupied or owned by The Practice.
The assessment will identify and consider all water sources including domestic and
non-domestic water systems where applicable for the risk of Legionellosis from work
activities and water sources on the premises and propose any necessary
precautionary measures or changes to the existing scheme of precautions. The
assessment will identify and evaluate all potential sources of risk and:
1) The particular means by which Legionella bacteria is to be prevented, or
2) If prevention is not reasonably practicable, the particular means by which the risk
of exposure to Legionella bacteria is to be controlled.
In addition, the Risk Assessment must consider the overall management scheme of
precautions and include the findings within the Risk Assessment report.
In the instance of problem areas and at the discretion of the responsible person, the
use of reassurance sampling during a Risk Assessment will also be considered and
although the recommendation will invariably be similar, reassurance sampling will
serve as an indicator and not a control measure.
It is important that Risk Assessments be undertaken in order to allow The Practice to
effectively manage and control the presence of Legionella bacteria and not just to
comply, as undertaking a Risk Assessment and not continuing with the
recommendations is still a non compliance, unless the Risk Assessment
demonstrates there to be no reasonably foreseeable risk or that the risks are
insignificant and unlikely to increase.
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UK Dental
MANAGEMENT RESPONSIBILITIES
Under the Control of Substances Hazardous to Health 2002 – Regulations 8 and 12,
Health and Safety at Work etc. Act 1974 – Sections 2, 3 and 4 and the Management
of Health and Safety at Work Regulations 1999 – Regulation 5 and the ACoP L8 the
Duty Holder (the person whom holds overall responsibility) should appoint a person
to take managerial responsibility and provide supervision of the implementation of
the scheme of precautions.
Duty Holder
The person on whom the overall responsibility falls shall be of an authoritative
position within The Practice (usually Chief Executive, Managing Director or Business
Owner) and have sufficient responsibility to authorise necessary precautions in the
event of an emergency or for planned works.
The Duty Holder shall appoint a suitably trained and competent person to the
position of Responsible Person whom will have responsibility for the day to day
operation of the scheme of precautions and management and control of
Legionellosis.
The Duty Holder shall oversee and be ultimately responsible for the Management
and Control of Legionellosis within the premises owned and occupied by The
Practice.
Where the business is small in nature the positions of Duty Holder and Responsible
Person are likely to be the same person.
Responsible Person (This is likely to be the Duty Holder also)
A Responsible Person shall be appointed by the Duty Holder to have responsibility
for the day to day operation of the scheme of precautions. The Responsible Person
shall be suitably informed and competent to ensure that the control measures will
be undertaken in a safe and technically competent manner.
The Responsible Person shall be in a managerial position or equivalent and also have
sufficient authority to authorise necessary precautions in the event of an emergency
or for planned works.
The Responsible Person will be closely involved in devising and the continual
reviewing or auditing of the scheme of precautions and their day to day
implementation.
The Responsible Person shall also hold responsibility for the undertaking of
Legionella Risk Assessments on a 2 yearly basis and for the Reviews of the Risk
Assessments as and when necessary for all properties that are owned or occupied by
The Practice.
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It will be the responsibility of the Responsible Person to carry out and oversee the
necessary remedial actions highlighted by the Risk Assessments and to maintain all
records associated to the Management and Control of Legionellosis for a period of 5
years and archive records for a period of 15 years.
The Responsible Person shall also ensure that all involved staff shall be suitably
trained to a competent level and that all contractors involved in the scheme of
precautions are suitably qualified and competent to undertake the tasks contracted
to them.
In the event of an outbreak or of the reporting of elevated results, the Responsible
person shall undertake to put in place the arrangements as per the outbreak and
elevated results procedure.
Deputy Responsible Person (Delete this position if not applicable to your practice)
A Deputy Responsible Person shall be appointed by the Duty Holder to have
responsibility for the day to day operation of the scheme of precautions and be
answerable to the Responsible Person. The Deputy Responsible Person shall be
suitably informed and competent to ensure that the control measures will be
undertaken in a safe and technically competent manner.
The Deputy Responsible Person will be closely involved in the day to day
implementations of the scheme of precautions and record keeping.
The Deputy Responsible Person will also assist in the overseeing of the necessary
remedial actions highlighted by the Risk Assessments and to maintain all records
associated to the Management and Control of Legionellosis for a period of 5 years
and archive records for a period of 15 years.
In the event of an outbreak or of the reporting of elevated results, the Deputy
Responsible Person shall assist the Responsible Person undertake to put in place the
arrangements as per the outbreak and elevated results procedure.
In the absence of the Responsible Person due to Holiday or illness or any other
reason, the Deputy Responsible Person shall undertake the duties of the Responsible
Person with guidance from the Duty Holder and approved Consultant/Contractor
until such time that the Responsible Person may be present to undertake such
duties, however in this instance, the overall responsibility fall on the Duty Holder
who should satisfy himself that adequate precautionary measures are undertaken.
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Consultant/Contractor
It is the responsibility of the Consultant/Contractor to ensure that all goods and
services be provided fit for purpose in a timely manner and to apply site knowledge
when discussing/consulting on the Management and Control of Legionellosis for The
Practice.
The Consultant/Contractor shall assist fully in necessary emergency procedures to
allow the Responsible Person/Deputy Responsible Person to complete their tasks.
Service Providers
Among other services, Legionella Management and Control is included in the
agreement between the Companies. Overall responsibility cannot be delegated to
service providers.
It is the responsibility of the Service Provider to undertake all tasks assigned to them
and ensure that records of all maintenance in connection to the Management and
Control of Legionellosis. The Service Provider shall liaise closely with the Responsible
Person to ensure continued compliance to the regulations.
General Staff
It is the responsibility of all staff involved in the Management and Control of
Legionellosis to ensure that all tasks in place under the scheme of precautions or pre
planned maintenance programme be undertaken in a complete and methodical
manner and all records are fully maintained.
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The following is a flow diagram of the management team and reporting routes:
Duty Holder
Responsible Person
Deputy Responsible
Person
Service Provider
Deputy Responsible
Person
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MANAGEMENT TEAM AND CONTACTS
The Management Team as per the Policy for the Management and Control of
Legionellosis that consist of the following; Duty Holder, Responsible Person, Deputy
Responsible Person, Service Provider, Consultant/Contractor and General Staff.
The positions below must be confirmed in writing informing those appointed of their
roles and responsibilities.
Position
Name
Contact Details
Duty Holder
INSERT YOUR NAME
INSERT YOUR ADDRESS
Responsible Person
INSERT YOUR NAME
INSERT YOUR ADDRESS
Deputy Responsible
Person
INSERT YOUR NAME
/ DELETE AS
APPLICABLE
INSERT YOUR ADDRESS/DELETE AS APPLICABLE
Haydn Harris MCIPHE
MWMSoc
T: 0785 22 152 43
Consultant/Contractor
Duncan Ravenscroft
BSc Hons MCIPHE
MWMSoc
T: 0750 09 381 04
Please call for full contact details
Local Environmental
Health Officer
Insert the details of
your local Health
Protection
Agency/Public
Health Agent.
Obtain details from
the website:
W:
www.hpa.org.uk/web/HPAweb&Page&HPA
webAutoListName/Page/1158945066055
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POLICY FOR THE CONTROL OF LEGIONELLOSIS
The Practice recognises and hereby accepts its responsibility under the Health and
Safety at Work etc. Act 1974, the Control of Substances Hazardous to Health 2002
and guidance document ACoP L8, to sufficiently manage and control the associated
risk from Legionella bacteria that may be present in the water systems operated by
The Practice and the potential for distribution of the bacteria in aerosols or water
droplets.
It is the Policy of The Practice to implement and operate this scheme of precautions
in recognition of the identified risks from Risk Assessments to all of the properties
and continually manage the program of works and maintain all records.
The Practice will also appoint a Responsible Person who will influence the scheme of
precautions and manage the day to day operations.
All properties currently occupied and owned and properties that become occupied
or owned by The Practice shall be included in the scope of this policy.
The Practice shall undertake to Manage and Control Legionella bacteria using the
methods discussed in the ACoP L8 including thermal disinfection, ionisation using
silver and copper, disinfection using and sufficient management as described later in
this document.
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MANAGING AND CONTROLLING LEGIONELLOSIS
In the first instance, The Practice, as a starting point of reference and to effectively
determine a progressive method of control, shall undertake to complete Risk
Assessments on all of the water systems in all of the buildings owned or occupied by
The Practice.
The Risk Assessment shall consider and recommend a method of control for
continued control of Legionella bacteria that may be present in a particular water
system.
It has been well documented that thermal control is an effective method of control
for Legionella bacteria growth. In the case of The Practice, thermal control will be
primary method of control for Legionella bacteria within the water systems operated
within the majority of the premises of The Practice.
Thermal disinfection will be achieved in each property by maintaining cold water
temperatures at <20°C at all times and by maintaining the domestic hot water at
>60°C at the hot water source or plant and >50°C at all outlets and if fitted to the
return supply to the hot water source.
In addition, to thermal disinfection and to aid thermal disinfection a number of other
treatment methods are in use for a number of the sites operated by The Practice,
these include: ionisation and chlorine dioxide. All water systems shall be maintained
in a clean condition including all cold water storage tanks, calorifiers, cistern type
water heaters and all associated pipework.
Furthermore, all systems that utilise water in any way whatsoever shall be used on a
frequent basis (at least weekly) or systems that do not get utilised on a frequent
basis shall be flushed on a twice weekly basis.
Where a Risk Assessment for staff or residents or persons has been undertaken for
the risk of scalding from hot water and has been deemed to be high, the use of
thermostatic mixing valves at each assessed outlet shall be considered.
In order that the scheme of precautions set out above can be successful, the
programme must be monitored at regularities set out in the ACoPL8, and under the
influence of the Responsible Person, depending on the plant operated and the
potential for persons to be exposed to droplets.
Records of all planned monitoring of the water systems shall be maintained and be
made available for the purposes of inspection.
During specific circumstances, when “Thermal Disinfection” is shown, by the various
Monitoring Tasks, to be failing, the water quality shall be maintained by ensuring the
shot-dosing of a suitable disinfecting agent, the levels of which must be maintained
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within the recommended limits for achieving disinfection as specified within the
current edition of BS6700:2006 Clause 3:1:10:1997 and ACoP L8.
The Practice will continue to consider new developments and improvements in the
field of Legionellosis Management & Control, in order to ensure that the control of
the prevailing risk of Legionellosis posed by the various systems is constantly
reviewed and improved and always maintained at the maximum level.
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SYSTEM DESIGN CONSIDERATIONS
The Practice shall, for all its water systems located in and out of any of the properties
currently occupied or owned and deemed to be the responsibility of The Practice as
described in the introduction of this document and the Policy for the Management
and Control of Legionellosis, as far as is reasonably practicable, ensure compliance to
the ‘Water Supply (water fittings) Regulations 1999’ and in accordance with ACoP L8
BS6700 and BS6920 as the materials and operation of the water systems can affect
the quality of the water.
In addition, The Practice shall as far as reasonably practicable, eliminate or reduce
the potential for dissemination of water droplets or aerosols and exposure to the
general population.
The systems shall be maintained in a clean and sound condition and must be easily
and safely accessible.
All systems will be frequently used (at least weekly), or flushed to simulate the
necessary usage frequency, in order to avoid stagnant water which will increase the
potential of bacterial growth and proliferation. The usage frequency shall be
regularly monitored and reported upon.
All plant and distribution pipe-work (where accessible) shall be clearly labelled.
COLD WATER STORAGE TANKS (CWSTs)
All CWSTs shall comply with the Water Supply (water fittings) Regulations 1999;
where a unit does not currently meet the requirements of the Water Supply (water
fittings) Regulations 1999 it shall be upgraded at times that are reasonably
practicable.
This should ensure that the unit is protected against the ingress of external foreign
materials, the unit will be sized and arranged to minimise retention of stored water
to 12 hours maximum and have a sequential throughput of fresh water, the unit and
associated pipework shall be suitably insulated and correctly labelled to identify its
purpose, the use of delayed-action ball valves shall be fitted (where practicable) in
order to help avoid stagnation of water, where automated booster pumps are
installed; a break tank shall be installed to eliminate the potential for backflow into
the incoming main.
All CWSTs shall also be constructed from materials which cannot shatter or provide a
source of contamination and must be (WRAS) approved.
All newly installed CWSTs shall be designed in accordance with BS6700 (GRP tanks
should comply with BS7491 Parts 1, 2 and 3) and installed in locations to allow easy
and safe access to aid inspection and maintenance.
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All CWSTs shall be maintained at a temperature of no more than 20°C at all times or
a maximum of 2°C no greater than the incoming main temperature.
CWSTs shall be subjected to an annual drop test or when a tank is found to have
stagnant conditions (as per ACoP L8 paragraph 182 (b)) to determine the usage
profile of the services the unit supplies (this entails the isolation of the make up to
determine of the water retention of the tank is <24hours) and if necessary reduce
the amount of stored water within the tank depending on any changes in the use of
the service.
A need test will be undertaken usually biennial by or at the request of the
Responsible Person to determine if the unit may be removed and the services it
supplies converted to incoming mains. This is usually a visual inspection taking into
consideration the age and remaining working life of the tanks and its current
potential risk. All results of the above tasks will be recorded within a Legionella
Control Logbook.
When undertaking a ‘need test’ visually or using The Practice’s records, it is
determined that the tank is at the end of its useful life, the tanks and system where
reasonably practicable, should be replaced with a system that does not utilise stored
water.
HOT WATER CALORIFIERS, XPHE AND WATER HEATERS
Calorifiers, XPHEs and water heaters will be installed in appropriate and suitable
locations to allow easy and safe access to facilitate inspection and maintenance.
The unit and associated pipework shall be constructed as such to aid maintenance
and maintained as such to manage and control the potential for proliferation of
Legionella bacteria.
The cold feed to calorifiers (>150 litres) shall be protected against the warming up
from the unit by the installation of a backflow prevention device to the cold feed as
close to the unit as possible. Where a calorifier utilises the cold feed as a means of
expansion, a ‘S’ bend or ‘thermal trap’ shall be fitted to the cold feed of the unit so
that water that has been warmed up may not flow back into the cold supply.
Each calorifier shall be adequately insulated against the effects of heat loss and be
maintained in good working order.
Expansion vessels shall be located on the cold feed rather than on the hot water side
of the system. The length of pipework between the expansion vessel and cold feed
shall be as short as possible, e.g. less than 1 metre. Expansion vessels shall be
subjected to a weekly flushing regime (if practicable). Ensure that the diaphragm (or
bag) is not damaged during the process.
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Calorifiers shall be fitted with an anti-stratification pump, where necessary, in order
to avoid temperature stratification of the body of stored water. Some semistorage/high-efficiency Calorifiers are supplied with an integral pump that circulates
water in the Calorifier. De-stratification pumps shall not be fitted to this type of unit.
Any circulation pumps fitted to the system shall normally be installed to the return. If
dual pumps have been fitted to the service, they shall be arranged to be
automatically switched on at least a weekly basis. Records of all switching shall be
maintained.
The calorifier shall be fitted with a suitable drain to aid maintenance and inspection
on the unit.
Cistern water heaters shall be maintained such that the cold tank part of the heater
is kept clean and at the correct temperature (ideally at <20°C, although this may not
be achievable during periods of low usage), and the hot tank part maintained at a
temperature of >60oC allowing for distribution temperatures of >50oC. A screened
vent and an insect/rodent overflow screen shall be fitted to the tank part of the unit.
Instant point of use water heaters (POUH), including combination boilers, usually
store small water volumes (units up to 30 litres), and because of this they do not
usually need to be operated within the temperature profile and limits prescribed for
larger systems (≥60oC for the ‘flow’ and ≥50oC for the ‘return’ and ‘outlet’) which are
necessary for thermal disinfection. These units can, therefore, be operated at user
preference temperatures although they should be switched-on at all times to ensure
and encourage sufficient usage.
HOT AND COLD WATER DISTRIBUTION SYSTEMS
The design and installation of the hot and cold water distribution system shall
comply with the Water Supply (Water Fittings) Regulations 1999 and BS6700.
The systems should be designed as such to prevent cross-connection between
wholesome and non wholesome supplies taking into account the fluid categories
described in Water Supply (Water Fittings) Regulations 1999.
All pipework runs shall be installed and located as such to avoid thermal cross over
between hot and cold services and from the environment to the cold service and
shall also be insulated against the effects of temperature gain and heat loss.
All pipework shall be installed to avoid blind loops and dead-ends or dead-legs and
where a service is removed from the system, all dead-legs shall be removed from the
pipework. In addition, all pipework shall be adequately sized in order to reduce the
potential for stagnation within the supplies.
Drinking water shall be provided directly from the incoming main or via a dedicated
drinking water supply system.
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The water supply to vending and ice making equipment shall be taken from a
wholesome supply up stream of a regularly used outlet with the minimum of
intervening pipe run i.e. less than 3 metres.
The domestic hot water system shall not be used for heating purposes. This includes
all radiators, towel rails, heated bedpan racks etc, whatever the pipework
configuration.
Central “common blending” systems will not be used (for example in commonly
blended shower blocks), since the length of distribution pipework containing water
in the temperature range that supports bacterial growth and proliferation would far
exceed the maximum permissible lengths of pipework of 2 metres in length.
Where shower blocks and some systems exist that have already been installed as
such, the installation of auto-drain valves will be considered, and the regular flushing
of the systems will be undertaken.
All TMVs shall be accessible (as far as reasonably practicable).
All TMVs fitted to baths and showers shall be inspected and subjected to a fail-safe
test on a six-monthly basis (carried out as described in the manufacturer’s
instructions).
Fire hose-reels which are supplied by the Domestic Mains, where the line supplying
the hose-reels is exclusive, distinct and separate from the line supplying domestic
facilities, the fire line shall be fitted with a suitable RPZ valve. Where the fire and
domestic supplies share the same line, each hose-reel spur shall be fitted with a
double check valve. It is important, however, to ensure that the valves are fitted as
close to the domestic line as possible in order to ensure that the dead-leg up-to the
valves is kept as small as possible.
Where the installation of RPZ or double check valves is not practicable, each unit
shall be subjected to a weekly flushing regime in order to minimise stagnation and
the potential for increased bacterial proliferation.
Although generally not fitted throughout the properties The Practice are responsible
for, in the event of future installation, plumbed eyewash units should be flushed
weekly to reduce bacterial contamination and to verify proper operation. The water
in a self-contained eyewash station must be refilled, disposed, and maintained in
accordance with manufacturer’s instructions. Emergency showers should also be
flushed weekly to flush the line and verify proper operation.
“WET” AIR HANDLING UNITS (AHUs)
All “Wet” AHUs shall be maintained in a good and clean condition and free from
excessive corrosion and dirt deposition.
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The material used to construct the unit shall not be of a material that may
contaminate the unit and its water supply.
All “Wet” AHUs will be designed so that any water/condensate collected is
discharged fully, freely and as quickly as possible (1 in 20 drop) and all associated
drip-trays must be designed so that they can be easily accessible for cleaning and
disinfection.
The drainage system fitted to the AHU shall be fitted with a suitable ‘type A’ trap or
u bend constructed from suitable materials for the premises.
WATER SOFTENERS
Water softeners may, if not installed and maintained in a sufficient manor, allow
growth of bacteria within the resin bed of the vessel and associated pipework.
All water softeners will be made from WRc approved materials and maintained in
line with the manufactures recommendations.
Each unit shall be maintained full of salt for the production of brine to complete the
regeneration process, and the unit automatically regenerated in accordance with the
usage requirements as the unit was set up.
Water softeners require to be serviced on at least an annual basis and the usage
requirements and regeneration times should be considered at this time.
The unit, its associated brine tank, and the surrounding environment shall be
maintained in a clean condition at all times.
ICE MAKING MACHINES
Ice is defined as food under the Food Safety Act 1990 and must be made, stored and
handled so that it is not contaminated, a requirement of the Food Safety (General
Food Hygiene) Regulations 1995.
Although generally not fitted to any of the properties The Practice are responsible
for, in the event that an ice making machine is installed, they should be well
managed.
Ice making machines are generally not considered to be a source of increased
bacterial proliferation however, if not properly maintained or used they can suspend
certain bacteria in a dormant state which may pose a risk during periods of usage or
when ice is allowed to melt.
In order to control the potential of microbiological and other contamination, the
following actions shall be considered and implemented:
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The supply to the unit shall be directly from the domestic incoming main and the
supply pipe is as short as possible and the machine shall be located away from any
heat sources (such as radiators and hot water pipework).
The machine will be used in conjunction with the manufactures instructions, with
regard to ambient temperatures, ventilation, water, electrical and drain
connections.
The machine will be cleaned and disinfected in accordance with the manufactures
instructions; this should include the disposal of ice within the machine which should
now be considered contaminated.
All tools or scoops being used in conjunction the machine shall also be cleaned and
disinfected.
ALL OTHER SYSTEMS
All water systems located on or in any property owned, occupied, or managed and
deemed the responsibility of The Practice shall be constructed from materials that
cannot provide a nutrient source for bacteria proliferation or support bacterial
growth.
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PRE PLANNED MAINTENANCE AND REVIEWS
As dictated by the Risk Assessments all systems shall be monitored in order to
ensure that the systems are operating within the control limits set out as per the
‘ACoP L8’.
All tasks undertaken for the control of Legionellosis shall have the results recorded
and maintained in a logbook system that shall be maintained for 5 years.
The tasks as per ACoP L8 and to be undertaken by The Practice are as follows:
(The following tables are extracts from the ACoP L8. Some of the services listed here may not be present within
all of The Practice’s properties)
ACoP L8 Appendix 1 Checklist 2: Hot and Cold Water Services
Service
Task
Hot water services
Cold water services
Shower heads
Little-used outlets
Arrange for samples to be taken from hot water
calorifiers, in order to note condition of drain
water
Check temperatures in flow and return at
calorifiers
Check water temperature up to one minute to
see if it has reached 50oC in the sentinel taps
Visual check on internal surfaces of calorifiers
for scale and sludge. Check representative taps
for temperature as above on a rotational basis
Check tank water temperature remote from ball
valve and mains temperature at ball valve.
Note maximum temperatures recorded by fixed
max/min thermometers where fitted
Check that temperature is below 20oC after
running the water for up to two minutes in
sentinel taps
Visually inspect cold-water storage tanks and
carry out remedial work where necessary.
Check representative taps for temperature as
above on a rotational basis
Dismantle, clean and de-scale shower heads
and hoses
Flush through and purge to drain, or purge to
drain immediately before use, without release
of aerosols
Frequency
Annually
Monthly
Monthly
Annually
Six monthly
Monthly
Annually
Quarterly or as
necessary
Weekly
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ACoP L8 Section 169 Table 3: Monitoring the Temperature Control Regime.
Standard to meet
Frequency
Check
Notes
Cold water
Hot water
Monthly
Sentinel taps
The water
temperature should
be below 20oC after
running the water
for up to two
minutes
If fitted, input to
TMV's on a sentinel
basis
Water leaving and
returning to
calorifier
Six monthly
Annually
Incoming cold
water inlet (at least
once in the winter
and once in the
summer)
Representative
number of tabs on
a rotational basis
The water
temperature should
be at least 50oC
within a minute of
running the water
This check makes sure
that the supply and
return temperatures on
each loop are
unchanged, i.e. the loop
is functioning as
required
The water supply to
the TMV
temperature should
be at least 50oC
within one minute
of running the
water
One way of measuring
this is to use a surface
temperature probe
Outgoing water
should be at least
60oC, return at least
50oC
If fitted, the
thermometer pockets at
the top of the calorifier
and on the return leg
are useful points for
accurate temperature
measurement.
If installed, these
measurements could be
carried out and logged
by a building
management system
The water should
preferably be below
20oC at all times (but
see paragraph 156 of
L8)
The water
temperature should
be below 20oC after
running the water
for two minutes
The most convenient
place to measure is
usually at the ball valve
outlet to the cold water
storage tank
The water
temperature should
be at least 50oC
within one minute
of running the
water
This check makes sure
that the whole system is
reaching satisfactory
temperatures for
legionella control
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ACoP L8 Appendix 1 Checklist 3: Other Risk Systems
System/Service
Task
Ultrasonic humidifiers/
foggers and water
misting/spraying
systems
If equipment fitted with UV lights, check to ensure
effectiveness of lamp (check to see if within working life) and
clean filters
Ensure automatic purge of residual water is functioning
Clean and disinfect all wetted parts
Sampling for Legionella
Spray humidifiers, air
washers and wet
scrubbers
Water softeners
Clean and disinfect spray humidifiers/air washers and makeup tanks including all wetted surfaces, de-scaling as necessary
Confirm the operation of non-chemical water treatment (if
present)
Clean and disinfect resin and brine tank - check with
manufacturer what chemicals can be used to disinfect resin
bed
UK Dental
Frequency
Six monthly or according
to manufacturer's
instructions
As part of machinery
shut down
As indicated by Risk
Assessment
As indicated by Risk
Assessment
Six monthly
Weekly
As recommended by
manufacturers
Emergency showers
and eye wash sprays
Flush through and purge to drain
Six monthly or more
frequently if
recommended by
manufacturers
Sprinkler and hose reel
systems
When witnessing tests of sprinkler blow - down and hose
reels ensure that there is minimum risk of exposure to
aerosols
As directed
Clean and disinfect storage and distribution system
Six monthly
Check filters - sand filters should be backwashed daily
Check water treatment - pools should be continuously
treated with an oxidising biocide
Clean and disinfect entire system
Clean and disinfect distribution pipework, spray heads and
make-up tanks including all wetted surfaces, de-scaling as
necessary
Check filtration and treatment system, clean and disinfect
system
Top up the screen wash to all vehicles using a suitable
additive solution mixture.
Clean and disinfect ponds, spray heads and make-up tanks
including all wetted surfaces, de-scaling as necessary
Daily
Lathe and machine
tool coolant systems
Spa baths
Horticultural misting
systems
Vehicle washes
Vehicle Screen Wash
Systems
Indoor fountains and
water features
Three times daily
Weekly
Annually
As manufacturers'
instructions
Weekly
Interval depending on
condition
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Monitoring of alternative treatment regimes:
Where an alternative treatment regime has been installed into a site the treatment
regime will be monitored and additional sampling for Legionella completed as
recommended in accordance with ACoP L8 Part 2 Paragraph 174 and 178 (paras 180
– 182 also included).
‘Monitoring the Chlorine Dioxide regime’
‘174 For most systems, routine inspection and maintenance will usually be sufficient
to ensure control see paragraphs 180-182) if the following areas are checked at
regular intervals and remedial action taken when necessary, with details of all
actions being recorded (see also paragraph 172):
(a) the quantity of chemicals in the reservoir;
(b) the rate of addition of chlorine dioxide to the water supply;
(c) on a monthly basis, the concentration of chlorine dioxide should be measured at
the sentinel taps - the concentration should be at least 0.1mg/l; and
(d) on an annual basis, the chlorine dioxide concentration at a representative number
of outlets - the concentration should be at least 0.1mg/l.
‘Monitoring the ionisation regime’
‘178 For most systems, routine inspection and maintenance will usually be sufficient
to ensure control (see paragraphs 180-182) if the following parameters are also
monitored at regular intervals and remedial action taken when necessary, with
details of all actions being recorded (see also paragraph 172):
(a) the rate of release of copper and silver ions into the water supply;
(b) the silver ion concentrations at sentinel outlets should be checked monthly - this
should be at least 20μg/l at outlets;
(c) the measurement of silver ion concentrations at representative taps selected on a
rotational basis once each year - this should be at least 20μg/l at outlets;
(d) the condition and cleanliness of the electrodes; and
(e) the pH of the water supply.’
‘General Monitoring’
The ACOP says that the risk from exposure to Legionella should be prevented or
controlled and that the precautions taken should be monitored to ensure that they
remain effective. The following section on monitoring offers guidance on how to
achieve this in hot and cold waters systems.
180 All water services should be routinely checked for temperature, water demand
and inspected for cleanliness and use. Ideally, the key control parameters should be
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monitored by a building management system if one is present. This will allow early
detection of problems in maintaining the control regime.
181 The frequency of inspection and maintenance will depend on the system and the
risks it presents. All the inspections and measurements should be recorded and
should include:
(a) The name of the person undertaking the survey, signature or other identifying
code, and the date on which it was made (computer records are acceptable); and
(b) A simple description and plan of the system and its location within and around the
building. This should identify piping routes, storage and header tanks, calorifiers and
relevant items of plant, especially water softeners, filters, strainers, pumps and all
water outlets.
Annual check
182 This should comprise the following.
(a) Visual inspection of the cold water storage tank to check the condition of the
inside of the tank and the water within it. The lid should be in good condition and fit
closely. The insect screen on the water overflow pipe should be intact and in good
condition. The thermal insulation on the cold water storage tank should be in good
condition so that it protects it from extremes of temperature. The water surface
should be clean and shiny and the water should not contain any debris or
contamination. The cold water storage tank should be cleaned, disinfected and faults
rectified, if considered necessary. If debris or traces of vermin are found then the
inspection should be carried out more frequently.
(b) Making a record of the total cold water consumption over a typical day to
establish that there is reasonable flow through the tank and that water is not
stagnating. This can be done by fitting a temporary water flow meter over the outlet
pipe and recording the consumption. It can also be measured by holding the ball
valve supplying the water in the closed position and measuring the rate of water level
drop within the vessel. Whenever the building use pattern changes, this
measurement should be repeated.
(c) Draining the calorifier and checking for debris in the base of the vessel. The
calorifier should then be cleaned if considered necessary.
(d) Checking the plans for both the hot and cold water circuits to make sure they are
correct and up to date - this should be done by physical examination of the circuits, if
possible. Plans should be updated if necessary.
(e) Ensuring that the operation and maintenance schedules of the hot and cold water
systems are readily available and up to date with named and dated actions
throughout the previous year.
(f) Checking the existence of all water connections to outside services; kitchens, fire
hydrants and chemical wash units. Any insulation should be checked to ensure that it
remains intact. Any water outlets that are no longer used should be removed.
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RE PLANNED MAINTENANCE TASK SPECIFICATIONS
TASK
PAGE
DEAD-LEG AND INFREQUENTLY USED OUTLET FLUSHING
19
COLD WATER STORAGE TANK TEMPERATURE MONITORING
20
COLD WATER STORAGE TANK GENERAL CONDITION
21
TANK CLEANING
22
CALORIFIER MANUAL TEMPERATURE MONITORING
23
CALORIFIER GENERAL CONDITION INSPECTIONS
24
COLD WATER TEMPERATURE MONITORING - DCWS & MAINS SUPPLY OUTLETS
25
HOT WATER TEMPERATURE MONITORING - DIRECT FED OUTLETS
26
HOT WATER TEMPERATURE MONITORING - BLENDED OUTLETS
27
SHOWER HEAD CLEANING AND DISINFECTION
28
THERMOSTATIC MIXING VALVE (TMV) CLEANING AND DISINFECTION
29
AHU TRAP CLEANING AND DISINFECTION
30
COMPONENTS INSPECTION, CLEANING AND DISINFECTION OF PERMANENTLY
OR INTERMITTENTLY WETTED SURFACES WITHIN THE AIR HANDLING SYSTEM
31
EXTERNAL WATER FOUNTAIN CLEANING AND DISINFECTION
32
TAKING AND INTERPRETING DIPSLIDES
33
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DEAD-LEG AND INFREQUENTLY USED OUTLET FLUSHING
When a system or water outlets is not frequently used, the conditions within the
disused areas can be ideal for the development of stagnant water conditions, and
can increase the potential for bacterial growth, including Legionella, within the
pipework and disused outlets.
A flushing programme will be aimed to remove the stagnated products that may
have occurred or reduce the potential for stagnation occurring within the pipework.
In the first instance, the idea is to completely remove the dead leg pipework from
the system or reduce it in length to <350mm.
It is important to ensure that the affected outlet/s be flushed for an appropriate
length of time to allow for the complete purging of the outlet and its pipework.
1) Identify areas/outlets to be flushed.
2) Ensure that the system/outlet can be flushed for a minimum of 2 minutes, safely
and in a tidy manner into an appropriate drain if not plumbed for drainage.
3) Ensure that the flushing of water from outlets does not create an unnecessary
amount of aerosol (this can be achieved by wrapping a towel or clean cloth
around the outlet and turning on the outlet slowly at first).
4) Run the hot and cold or the mixed water in turn for a minimum of 2 minutes or
for a period of time necessary to draw water from the outlet at temperatures
exhibited throughout the rest of the system.
5) If an area consisting of a number of outlets require flushing, it is important to
begin with the nearest outlet to the main distribution pipe work, working
progressively away from the main distribution pipe work.
6) Where showers need to be flushed, it is important to ensure that, where
practicable, the shower-head is removed in order to reduce the potential of
aerosol production. Where the head is fixed, exposure to the aerosol produced
must be minimised. One method that can be employed in this situation is the use
of a transparent plastic bag, fixed around the shower- head, with one corner
pierced to allow partial discharge of water.
7) Log all procedures and results.
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COLD WATER STORAGE TANK TEMPERATURE MONITORING
1) Care should be taken not to contaminate the tank from any loose materials that
may fall into the unit and by using clean equipment.
2) Care should also be taken when gaining access to the internal parts of the tank –
do not put yourself or any other in any unnecessary danger.
3) Using an electronic and calibrated thermometer, measure, and record the
temperature of the body of the stored water. Although in some cases this is not
possible, the measurement of the stored water temperature should be as far
away from the ball valve as possible.
4) If not operating, depress the ball valve and measure the temperature of the
water after allowing a suitable flush of the make up water.
5) Measure and record the ambient temperature near to where the tank is located.
6) Ensure that all log sheets are filled in fully.
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COLD WATER STORAGE TANK GENERAL CONDITION
In order to ensure that tanks are maintained in as clean a condition as possible it is
important to ensure that the units be inspected on at least an annual basis and
possibly more often depending on the data obtained and the condition of the unit.
1) Care should be taken not to contaminate the tank from any loose materials that
may fall into the unit and by using clean equipment.
2) Care should also be taken when gaining access to the internal parts of the tank –
do not put yourself or any other in any unnecessary danger.
3) If the insulation allows for an inspection of the external condition of the tank
walls, inspect for corrosion pitting and leaks.
4) On gaining access to the internals of the tank, visually inspect internal walls of
tank for signs of scale, corrosion, sediment coverage of the base and slime/bio
film to the walls.
5) Inspect tank and associated valves/pipework for leaks and check valves for
operation.
6) Look for signs of stagnation such as water surface dirt, oil films, insects, smell,
low input, or temperature differential for multiple linked tanks.
7) Visually inspect for algae growth indicated by either green or red plant like
growth on water surface
8) Inspect the insulation looking for signs of wear or damage and areas where the
insulation has been removed
9) Ensure that the lid is correctly fitted and that any bolts are securely tightened.
10) Visually inspect if practicable that all insect/rodent screens fitted are clear from
debris.
11) Check that the ball valve operates correctly.
12) Visually inspect all booster pumps fitted for correct operation.
13) Ensure that the appropriate log sheets are filled in noting any areas of concern to
report to the Responsible Person or Deputy Responsible Person.
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TANK CLEANING
When a cold water storage tank becomes dirty, as directed by a monitoring
programme, it is necessary to clean and disinfect the internal parts of the unit to
reduce the potential for increased bacterial activity. The following procedure should
be followed:
1) Care should be taken not to contaminate the tank from any loose materials that
may fall into the unit and by using clean equipment
2) Care should also be taken when gaining access to the internal parts of the tank –
do not put yourself or any other in any unnecessary danger.
3) Isolate the tank from the system.
4) All of the water should be drained from the unit; if the unit is excessively dirty or
contaminated it should be disinfected using the disinfection procedure detailed
later in this procedure.
5) The internal surfaces of the unit shall be cleaned using scrubbing materials, jet
washer, and wet vacuum (no chemical dispersants are to be used at this stage).
6) Following full clean of the internal surfaces of the unit the unit shall then be
refilled. The pH of the water shall be measured and must be between 5.5 and 9.0
before chlorinating solution is introduced. If pH is found to be below 5.5 the
system shall be drained, flushed, and refilled with fresh water.
7) The chlorinating agent should give a minimum free chlorine concentration of
50ppm (50mg/l), and when full, allow to stand for 1 hour.
8) An allowance for pH adjustment should be followed in order to ensure sufficient
amounts of disinfecting agent are added, this may mean levels in excess of
50ppm (50mg/l) may need to be present depending on pH.
9) After 1 hour, measure free chlorine level. If free chlorine level is below 30ppm,
repeat steps 5 and 6.
10) The tank shall be drained and then thoroughly flushed out with clean mains
water until tests indicate that the residual chlorine concentration is no greater
than 0.5ppm (0.5mg/l), or that present in the mains water supply.
11) Where the volume exceeds 5000 litres, the disinfected water must be neutralised
using sodium thiosulphate before disposal. The neutralised waste should not be
drained through the system.
12) The tank shall then be refilled and confirmation should be given that no
disinfecting agent residue is present.
NB:
All PPE will be utilised for the purposes of tank cleaning and disinfection ensuring all
COSHH requirements including Risk Assessment are followed.
All confined space requirements and permits to work shall be followed.
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CALORIFIER MANUAL TEMPERATURE MONITORING
1) Care should also be taken when gaining access to the unit – do not put yourself
or any other in any unnecessary danger.
2) Record the ‘Set’ temperature setting of the thermostat. The temperature should
be >60°C.
3) Measure the ‘Flow’ temperature using a calibrated contact thermometer or
fitted gauge. Temperature to be taken from ‘Flow’ pipework as close to the
Calorifier as possible. The temperature should be >60°C.
4) Measure the ‘Return’ temperature using a calibrated contact thermometer or
fitted gauge. Temperature to be taken from ‘Return’ pipework as close to the
Calorifier as possible. The temperature should be >50°C.
5) Ensuring safe and suitable drainage facilities are present, close the cold feed and
open the drain of the calorifier and flush 5 litres. Take the temperature of the
drain water (closing the cold feed will ensure that the temperature is taken from
the base of the unit and not from the higher pressure cold feed). Note the
condition of the initial drain flush and subsequent flush water.
6) Re-instate the cold feed to the system without delay.
7) The base temperature should be >50°C.
8) Check the temperature to the cold feed to the calorifier using a calibrated
contact thermometer noting if there is a non return valve fitted. The
temperature of the cold feed should be <20°C at 1 meter from the unit.
Note: If contact probe is to be used for temperature monitoring through copper
pipework, a 2oC temperature adjustment must be added to the recorded
temperature before reporting temperature on the Log-sheet.
Note: The temperature measurements shall be carried out at different times during
the day in order to allow indicative temperature monitoring of the vessel
during a typical daily usage profile.
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CALORIFIER GENERAL CONDITION INSPECTIONS
1) Make a note of the operational status of the unit by checking the controls of the
unit. This may also be achieved by the checking of the associated isolation valves.
2) Inspect the external components of the calorifier, insulation, valves, pipework,
and pumps for leakage and general condition.
3) Record the ‘Set’ temperature setting of the thermostat. The temperature should
be >60°C.
4) Measure the ‘Flow’ temperature using a calibrated contact thermometer or
fitted gauge. Temperature to be taken from ‘Flow’ pipework as close to the
Calorifier as possible. The temperature should be >60°C.
5) Measure the ‘Return’ temperature using a calibrated contact thermometer or
fitted gauge. This will give an indication that the return pump is operating.
Temperature to be taken from ‘Return’ pipework as close to the Calorifier as
possible. The temperature should be >50°C.
6) Ensuring safe and suitable drainage facilities are present, close the cold feed and
open the drain of the calorifier and flush 5 litres. Take the temperature of the
drain water (closing the cold feed will ensure that the temperature is taken from
the base of the unit and not from the higher pressure cold feed). Note the
condition of the initial drain flush and subsequent flush water.
7) Re-instate the cold feed to the system without delay.
8) The base temperature should be >50°C.
9) Check the temperature to the cold feed to the calorifier using a calibrated
contact thermometer noting if there is a non return valve fitted. The
temperature of the cold feed should be <20°C at 1 meter from the unit.
10) Inspect any gauges that are fitted and that they are operating correctly. Compare
against calibrated instruments.
11) Visually inspect the trace heating. Using a calibrated contact probe check the
trace heating maintains the hot water at above 50°C and look carefully for cold
spots.
12) Ensure that the trace heating fitted to the cold pipework for frost protection is
set no greater than 20°C.
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COLD WATER TEMPERATURE MONITORING - DCWS & MAINS SUPPLY OUTLETS
1) Identify the first mains fed outlet closest to the incoming main. Using an
electronic and calibrated thermometer with a suitable probe, record the outlet
temperature after 2 minutes of flushing the outlet at full flow. The temperature
should not exceed 20°C at any time
2) Note any warm pockets of warm water during the 2 minute flush to identify any
warming up of the main.
3) Identify the sentinel outlets located on the distribution system (these are the
nearest and furthest outlets on the system i.e. main cold water and stored cold
water).
4) Record the outlet temperature of each designated ‘Sentinel’ outlet, from each
branch and sub-branch of the distribution system, indicating whether mains or
tank fed. The temperature shall be carried out as ‘2’ above.
5) Ensure all results are logged onto the appropriate log sheet.
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HOT WATER TEMPERATURE MONITORING - DIRECT FED OUTLETS
1) Identify the sentinel outlets located on the distribution system (these are the
nearest and furthest outlets on the system).
2) Record the outlet temperature (after 1 minute flushing at full flow), of each
identified ‘Sentinel’ outlet, from each branch and sub-branch of the distribution
system, indicating the source calorifier.
3) The minimum temperature recorded after 1 minute of flushing at full flow.
4) Make a note of the condition of the flush water indicating flow rates and any
discolouration of the water.
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UK Dental
HOT WATER TEMPERATURE MONITORING - BLENDED OUTLETS
Showers, Baths and Bidets and Other Non Full Immersion Outlets
1) Using a calibrated digital thermometer, record the ‘Initial’, and ‘Final’ outlet
temperature, of each shower and bath fitted with a Thermostatic Mixing Valve
(TMV). The measurements shall be carried out immediately and after allowing
the water to run for 1 minute at full-flow. The ‘Initial’ and ‘Final’ outlet
temperature measured shall not exceed:
41oC for showers.
44oC for baths.
37oC for bidets.
41°C for basins and other outlets.
2) Where these temperatures are exceeded, the TMV shall be adjusted in order to
allow the unit to operate within the recommended temperature limits described
above.
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SHOWER HEAD CLEANING AND DISINFECTION
1) For ease of service, each shower-head and associated hose (if fitted) shall be
removed from its location and replaced with a new or previously serviced
shower-head.
2) Each shower-head and associated hose shall be dismantled and physically
cleaned from all scale deposits and scale deposition (using a suitable de-scaling
solution where necessary. Ensure that this process is undertaken in a safe
manner in a suitable location.
3) Rinse in clean water, allow to drip-dry, and store in a cool and dry place.
4) Immediately prior to re-installation (same-day), all components shall be
disinfected (this applies to all cleaned and new components). All components
shall be flushed with clean water and immersed in a sodium hypochlorite
disinfectant solution (100 ppm) for 20 minutes minimum.
5) Remove components from disinfectant solution and rinse with clean water to
remove presence of chlorine.
6) Reassemble, refit, and test operation of shower.
7) Measure and record and adjust (if necessary) the ‘Final’ outlet temperature.
8) Record the date that the shower-head and associated hose have been replaced.
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THERMOSTATIC MIXING VALVE (TMV) CLEANING AND DISINFECTION
1) Each TMV shall be removed from its location and replaced with a new or
previously serviced TMV.
2) Each TMV shall be dismantled and physically cleaned from all scale deposits and
scale deposition (using a suitable de-scaling solution where necessary).
3) Rinse in clean water, allow to drip-dry and store in a cool and dry place.
4) Immediately prior to re-installation (same day), all components shall be
disinfected (this applies to all cleaned and new components). All components
shall be flushed with clean water and immersed in a sodium hypochlorite
disinfectant solution (100 ppm) for 20 minutes minimum.
5) Remove components from disinfectant solution and rinse with clean water to
remove presence of chlorine.
6) Reassemble, refit, and test operation of valve, including fail-safe test.
7) Measure, record and adjust (if necessary) the ‘maximum’ outlet temperature.
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AHU TRAP CLEANING AND DISINFECTION
1) For ease of working practice, remove each trap from its unit to take to a suitable
location for a safe method of working.
2) Each trap shall be dismantled and physically cleaned from all scale deposits and
scale deposition (using a suitable de-scaling solution where necessary).
3) Rinse in clean water, allow to drip-dry in a cool and dry place.
4) Immediately prior to re-installation, all components shall be disinfected (this
applies to all cleaned and new components). All components shall be flushed
with clean water and immersed in a sodium hypochlorite disinfectant solution
(100 ppm) for 20 minutes minimum.
5) Remove components from disinfectant solution and rinse with clean water to
remove presence of chlorine.
6) Reassemble, refit, and fill trap with clean water.
7) Record the date that the trap has been replaced.
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COMPONENTS INSPECTION, CLEANING AND DISINFECTION OF PERMANENTLY OR
INTERMITTENTLY WETTED SURFACES WITHIN THE AIR HANDLING SYSTEM
1) Note if the unit is operational.
2) Carry out an internal inspection of the condition of all external and internal
surfaces of the unit including drip trays, drainage and traps and comment.
3) If fitted, inspect and note the condition of the humidification pond.
4) Using clean cloth, wipe over the unit components to be disinfected. To disinfect,
spray the components with a chlorine solution of 100 ppm strength, using small
hand spray. Allow to stand for 3 mins only. Spray with fresh clean water. Dry area
with a clean cloth.
5) If fitted, drain and clean the pond area ensuring all surfaces are cleaned including
under drift eliminators is cleaned.
6) Refill the pond with fresh water and add chlorine solution to achieve 50ppm
reserve. Ensure that all normally wetted parts of the unit be sprayed by running
the circulation spray pump.
7) Drain the pond and thoroughly flush until all chlorine reserves are depleted.
8) Check there are no chlorine residues remaining inside the unit.
9) Re-fill the pond and bring the unit back into service.
10) Ensure that all log sheets be filled in fully.
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EXTERNAL WATER FOUNTAIN CLEANING AND DISINFECTION
When an External Water Fountain becomes dirty, as directed by a monitoring
programme, it is necessary to clean and disinfect the internal parts of the pond to
reduce the potential for increased bacterial activity and for visual appreciation. The
following procedure should be followed:
1) Isolate pond from water supply.
2) All of the water should be drained from the unit; if the unit is excessively dirty or
contaminated it should be disinfected using the disinfection procedure later in
this procedure.
3) The internal surfaces of the unit shall be cleaned using scrubbing materials, jet
washer and wet vacuum (no chemical dispersants are to be used at this stage).
4) Following full clean of the internal surfaces of the unit, the unit shall then be
refilled. The pH of the water shall be measured and must be between 5.5 and 9.0
before chlorinating solution is introduced. If pH is found to be below 5.5 the
system shall be drained, flushed and refilled with fresh water.
5) The chlorinating agent should give a minimum free chlorine concentration of
50ppm (50mg/l), and when full, allow to stand for 1 hour.
6) An allowance for pH adjustment should be followed in order to ensure sufficient
amounts of disinfecting agent are present.
7) After 1 hour, measure free chlorine level. If free chlorine level is below 30ppm,
repeat steps 5 and 6.
8) The pond shall be drained and then thoroughly flushed out with clean mains
water until tests indicate that the residual chlorine concentration is no greater
than 0.5ppm (0.5mg/l), or that present in the mains water supply.
9) Where the volume exceeds 5000 litres, the disinfected water must be neutralised
using sodium thiosulphate before disposal. The neutralised waste should not be
drained through the system.
10) The pond shall then be refilled and confirmation should be given that no
disinfecting agent residue is present.
NB:
All PPE will be utilised for the purposes of fountain cleaning and disinfection ensuring
all COSHH requirements including Risk Assessment are followed.
All confined space requirements and permits to work shall be followed.
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TAKING AND INTERPRETING DIPSLIDES
1) Ensure that the incubator is switched on as it takes 30 minutes to warm up.
Ensure that the incubator is set to approximately 30°C or the temperature of the
sampled source if vastly different. Take care when adjusting the heat setting of
the incubator as the unit will heat up to different temperatures depending on
ambient temperature conditions i.e. setting 3 will heat approximately to 37°C at
an ambient temperature of 20°C and well in excess of 45°C if the ambient
temperature is >30°C. The incubator should be located away from excessive heat
sources and direct sunlight.
2) The dipslides should be stored in a cool dry place and away from sunlight.
3) Take a dipslide and remove the clear tube to withdraw the combined cap/tongue
unit.
4) Do not at any point touch the gel as this will give a false reading. If the gel or part
of the slide touches any surfaces other than the intended sample surface, it will
give a false reading and should be discarded.
5) Immerse the gel and slide part of the dipslide in the fluid to be tested for about
10 seconds.
6) Allow the excess fluid to drip/drain for a couple of seconds before replacing the
clear tube.
7) Place the dipslide in the incubator checking the unit is at the desired
temperature and not in direct sunlight.
8) After 3 days check the dipslide against the comparison chart supplied with the
BTM2 dipslides to obtain a reading and mark on the appropriate log sheet. The
following actions should be taken depending on the results.
<104
105
= No further action required.
= Review the treatment regime and check treatment levels. If all is
ok, retake a sample.
>106
= Review the treatment regime and check treatment levels. Increase
the treatment (maintaining within safe limits) to undertake a shot dosing. If
the pool is visually contaminated arrange for a clean and disinfection to
carried out. Re-take a dipslide after 1 day of shot dosing, if the levels are still
elevated have the pool cleaned and disinfected at the earliest opportunity.
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RECORD KEEPING
It is the responsibility of the Responsible Person to ensure that the records are kept,
including details of:
1) The person or persons responsible for conducting the Risk Assessment,
managing, and implementing the written scheme of precautions.
2) The significant findings of the Risk Assessments.
3) The written scheme for Legionella control and details of its implementation.
4) The results and/or monitoring, inspection, test or check carried out, and the
dates and signature of the staff undertaking the task. This should include
details of the state of operation of the system, i.e. in use/not in use.
5) Details of remedial actions/works with dates and sign off on completion.
All current records shall be retained throughout the period in which they are current
and for at least 2 years after that period. Record results of any monitoring,
inspection or remedial actions should be kept for a period of at least 5 years
thereafter.
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POLICY MAINTENANCE AND REVIEW
This Policy for the Management and Control of Legionellosis shall be subject to a
yearly review from the date on the front cover and footer of this document in
order to allow for any changes in the legislation or regulations for the
Management and Control of Legionellosis.
The review shall take into account any changes in control methods that may
affect The Practice’s current methods of Legionella control. Any changes to the
policy and its affects on the scheme of precautions shall be discussed by the
Responsible Person and Duty Holder in order to allow for changes to the scheme
or precautions to comply with current legislation/regulation/guidance.
The review of this document may be undertaken by the Responsible Person, Duty
Holder, or Consultant to The Practice.
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Elevated Sample Procedure and Outbreak Procedure
It is important to note that elevated samples do not relate to increased colony
counts on a dipslide or drinking water sample. Elevated sample results relate to
Legionella samples only.
Legionnaire’s Disease became a notifiable disease on the 6th April 2010 in
England.
There is now a duty upon registered medical practitioners to notify the proper
officer or the relevant local authority of any suspected cases of Legionnaires’
disease. The notification must be provided in writing within three days from the
date of suspicion.
From the 1st October 2010 the operator of a diagnostic laboratory must notify
the Health Protection Agency when Legionella species are identified in a human
sample.
The Public Health Laboratory Service defines an outbreak as two or more
confirmed cases of Legionellosis occurring in the same locality within a six-month
period. Location is defined in terms of the geographical proximity of the cases
and requires a degree of judgement. It is the responsibility of the proper Officer,
who is appointed by the Local Authority under public health legislation and is
usually a Consultant in Communicable Disease Control for the declaration of an
outbreak.
In the event of a suspected outbreak, the Responsible Person shall undertake to
inform the proper Officer as detailed above.
Should an outbreak be declared, all persons involved from The Practice shall
follow the Outbreak Procedure detailed next.
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Outbreak Procedure
Please note: this Outbreak Procedure is not to be confused with the Elevated
Sample Procedure described in the following section.
As stated, an outbreak is defined as two or more confirmed cases of Legionellosis
occurring in the same locality within a six-month period and can only be declared
by the Local Authority Proper Officer.
In the event of an outbreak being declared and suspected to be sourced in the
locality of The Practice’s properties, it is important to ensure that the
Management Team, as described earlier, implement the following procedure to
effectively manage and control the suspected risk.
1) All individuals involved in the scheme of precautions will be involved in the
event of an outbreak. They shall be known as the ‘Major Outbreak Team’. It is
important for the major outbreak team (usually the Responsible Person) to
establish points of contact with the Local Health Authority or Hospital Trust
and the Local Authority Health Officer.
2) The Risk Assessment for the building affected should be addressed to assist in
identifying areas of most concern and likely areas for routes of infection.
3) All potential sources of generating an aerosol shall be taken out of use
(Showers, Air Handling Units, Cooling Units).
4) It is important to ensure that the systems suspected of being a potential
source of infection are NOT cleaned and disinfected to allow for sampling of
the system.
5) Samples of the source shall be taken and submitted to UKAS accredited
laboratory for analysis.
6) An investigation in the breakdown of the scheme of precautions shall be
undertaken. All aspects of the scheme of precautions shall be audited
including monitoring and record keeping.
7) By this time the Local Authority Public Health Officer (responsible for
declaring an outbreak) /Health and Safety Executive Officer may be closely
involved with the Major Outbreak Team. The Major Outbreak Team shall
comply fully with the requests of the Officer.
8) Under the instruction of the Public Health Officer all water systems shall be
cleaned and disinfected in accordance with BS6700:1997/ACoP L8.
9) All areas of concern such as showers, AHU and Cooling Towers shall be
addressed by the individual cleaning and disinfection of the items.
10) All systems shall be refilled and thoroughly flushed on a daily basis until the
system can be declared bacteria free. (It is important to maintain records of
all remedial actions before, during, and after the outbreak).
11) The system shall be re-sampled after 4 days of the system being cleaned and
disinfected to allow the system to stabilise although flushing of the system
shall continue.
12) Once the sampling regime shows there to be no Legionella bacteria present
in the system. The system shall be re-instated. Should the sampling suggest
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that there are still Legionella bacteria present above satisfactory levels, steps
7 to 10 shall be repeated paying particular attention to other sources that
may have been omitted from the previous procedure.
13) An immediate review of the Monitoring Programme shall be undertaken in
order to identify areas where the control scheme of precautions has failed to
effectively control the proliferation of Legionella bacteria and suggestions as
to necessary changes to the scheme of precautions for greater control.
14) The Major Outbreak Team shall continue to assist the investigating Officers of
the Outbreak Team.
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Elevated Sample Procedure
Elevated samples from the routine inspection/monitoring are not considered to be
an outbreak or indicative of or to an outbreak.
When the sampling programme yields elevated results from either dipslide
monitoring or Legionella or TVC sampling as detailed on the Measured Parameter
Recommended Limits table, the elevated sample procedure should be followed, this
is detailed below.
MEASURED PARAMETER RECOMMENDED LIMITS
The following information is to allow the maintenance staff to undertake tasks and
follow measured parameter limits for remedial action.
PARAMETER
SET POINT
Cold Water Temperatures
All Cold Water Outlets
Maximum 20°C
Hot Water Temperatures
Storage Calorifier Thermostat Set Point
Storage Calorifier Flow
Storage Calorifier Return
Storage Calorifier Drain/Base
Storage Calorifier Cold Feed
HWS Sentinel Outlets
Minimum 60°C
Minimum 60°C
Minimum 50°C
Minimum 50°C
Maximum 20°C
Minimum 50°C
Cistern Type Water Heater Thermostat Set Point
Cistern Type Water Heater Flow
Cistern Type Water Heater Clod Feed/Tank
Section
Cistern Type Water Heater HWS Outlets
Minimum 60°C
Minimum 60°C
Instant Water Heaters <30 Litres Thermostat Set
Point
Instant Water Heaters <30 Litres Flow
Instant Water Heaters <30 Litres Cold Feed
Instant Water Heaters <30 Litres HWS Outlets
Maximum 20°C
Minimum 50°C
User Comfort Temperature
User Comfort Temperature
Maximum 20°C
User Comfort Temperature
Blended Outlets
Showers
Maximum 41oC
Basins/Sinks
Baths
Bidets
Maximum 41oC
Maximum 44oC
Maximum 37oC
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Measured Parameters Continued:
Biological Contamination
Legionella Bacteria <100 cfu/litre
Legionella Bacteria >100 but <1000 cfu/litre
Legionella Bacteria >1000 cfu/litre
Growth Is Insignificant
Growth is Significant
Growth is Highly Significant
For Drinking Water
T.V.C. Total Viable Count <50 cfu/ml
T.V.C. Total Viable Count >50 cfu/ml and
<500cfu/ml
T.V.C. Total Viable Count >500cfu/ml
Growth is Insignificant
Growth is Significant
Growth is Highly Significant
E. COLI and Coliforms
<1cfu/ml
>1cfu/ml
Growth is Insignificant
Growth is Highly Significant
Dipslides
Bacteria/Yeasts <104
Bacteria/Yeasts >104 to >106
Insignificant Growth
Significant Growth
Mould <102
Mould 103 to 104
Insignificant Growth
Significant Growth
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ELEVATED SAMPLE PROCEDURE
The following should be read in reference to the above table noting only some of
the recommendations are applicable to the item mentioned above.
Insignificant
1) No further action required, maintain current monitoring regime.
Significant
2) Clean, de-scale and disinfect all removed shower heads and outlets and
replace onto system immediately following disinfection.
3) Carry out a system clean and disinfection (within 2 days of results) and resample after 4 days from disinfection.
4) If result still persists, repeat de-scale, clean and disinfection and re-sample
after 4 days from disinfection.
5) If result still persists follow procedures described in the Highly Significant
section below.
6) Consider the source of contamination.
Highly Significant
7) Isolate system and carry out a system clean disinfection immediately or at
least before the system is used again. Re-sample after 4 days from
disinfection.
8) Remove all shower heads in contaminated area until post-disinfection
biological analysis indicates the removal of contamination.
9) Clean, de-scale and disinfect all removed shower heads and replace onto
system when post-disinfection biological analysis indicate the removal of
contamination. Ensure that shower heads are in a dry state while
disconnected to prevent stagnation.
10) Where showers are required to remain in use following indication, they shall
be fitted with a suitable HEPA filter to enable continued use of the facility.
Where such filters are fitted, they should be changed according to
manufacturer’s instructions.
11) If result still persists, repeat system clean and disinfection and re-sample
after 2 days from disinfection and reconsider sources of contamination.
FAULT RECTIFICATION TIME SCALES PROCEDURES:
It is important to ensure that response times to recommended remedial
actions are strictly adhered to in order to ensure Legionellosis is effectively
controlled.
The following table suggests fault rectification timescales, it is important to aim
to follow a strict timescale; however a degree of discretion may be required to
prioritise multiple faults depending on severity and urgency:
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Time-Scale for
Reporting of Fault
Time-Scale for
Remedial Works
Same-day
Same-day
Same-day
Same-day
HWS distribution system temperatures outside the
recommended temperature limits, i.e. <50°C for the outlets.
Same-day
24 hours
ClO2 (Chlorine Dioxide) levels below recommended limits.
Same-day
24 hours
Calorifiers requiring disinfection due to biological
contamination.
Same-day
48 hours
Calorifiers requiring disinfection due to low temperatures for a
prolonged period of time.
Same-day
48 hours
Tanks requiring disinfection due to biological contamination.
Same-day
48 hours
Tanks requiring disinfection due to excessive sediment
presence.
Same-day
Within 1 Month
Whole system requiring disinfection.
Same-day
48 hours
CWS temperatures at source units (tanks) outside the
recommended temperature limits.
24 hours
48 hours
CWS distribution system temperatures outside the
recommended temperature limits.
24 hours
48 hours
Tanks/Calorifiers requiring refurbishment/upgrading.
24 hours
Within 3 months
Fault Reported
HWS temperatures at source units outside the recommended
temperature limits, i.e. <60°C for the flow and storage or <50°C
for the return/drain.
Biological analysis results reported as being outside the
recommended limits (on notification from laboratory).
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