Legionella Policy.pdf - North Somerset PCT

northsomerset.nhs.uk

Legionella Policy.pdf - North Somerset PCT

North Somerset


Control of Legionella

Policy

Author(s):

Lead Clinician (if

appropriate):

In consultation with:

To be read in

association with:

Ben Littlewood-Hillsdon

Vicki Lovis

Gwen Hobbs

HPA

Health and Safety Policy

Risk assessment policy and

Procedures

Risk Management strategy

Incident reporting Policy and

Procedures,

Serious Untoward Incident policy

Control of Infection Policy

Outbreak Policy

Ratified by:

Control of Infection Committee

Issue/Ratification date: August 2009

Review date: December 2010

If you require this document in a different format,

please telephone the Corporate Manager on

01275 546717

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Contents

1 Purpose page 3

2 Scope page 3

3 Background page 3

4 Responsibilities page 4

4.1 The Chief Executive & Board

4.2 Director of Public Health

4.3 All Employees

4.4 Estates & Facilities

4.5 Health & Safety Manager

5 Water temperature and Legionella bacteria proliferation page 5

6 Intermittently/Infrequently used Outlets and Showers page 5

7 Monitoring and Record Keeping page 6

8 Planned Preventative Maintenance (PPM) Schedule page 6

9 Control Methods page 7

10 Action in the Event of a Suspected Outbreak or Incident page 7

11 Further Information

Appendix 1 - Design & Installation of Building Services page 9

Appendix 2 – Legionnaire’s Disease page 12

Appendix 3 – Principal Legislation page 15

Appendix 4 – Guidance page 18

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1. Purpose

To provide NHS North Somerset with a safe place of work in which the management and

control of Legionella is such that the risk of infection to employees and patients is so far

as reasonably practical reduced to a minimum. The overall aim of this policy is to

describe the responsibilities undertaken by the PCT and their staff or agents acting on

their behalf in the commissioning and maintenance of effective strategies for the control

of the risk from Legionella bacteria. Through the arrangements described in the

Management and Control Procedures and written schemes, operate and maintain safe

water systems in which legionella bacteria are kept to a safe and acceptable limit and

maintain compliance with the Health and Safety Executives Approved Code Of Practice

entitled Legionnaires' disease: The control of legionella bacteria in water systems (L8). In

so doing, fulfill the requirements of the Health and Safety at Work ACT 1974.

2. Scope

NHS North Somerset recognises it has statutory responsibilities as an employer and a

healthcare provider under the Health and Safety at Work Act, the Management of Health

and Safety at Work Regulation and the Control of Substances Hazardous to Health

Regulations. The intention is to use the requirements of these regulations as a minimum

standard for the prevention of bacteria growth within building and building services and to

prevent patients, visitors and staff being exposed to Legionella bacteria.

3. Background

Legionella Pneumophila and other bacteria can cause an infection known as

Legionellosis. Legionnaire’s disease is a pneumonia that principally affects those

who are susceptible, due to age, illness, immunosupression, smoking, etc, and

may be fatal. However it is a significant health issue for anyone who is exposed

to the aerosols of the bacteria. Legionella bacteria are present in water systems

and do not pose a health concern if the appropriate control measures are in place

and maintained. The risk from Legionella bacteria increases if the water in the

systems is stagnant (i.e. in ‘dead legs’ or when the system in not in use for a

period of time) and bio-film can develop on the inside of the water pipes, this biofilm

provides nutrients and encourages proliferation of the bacteria. Legionella

proliferation can be suppressed by controlling the water temperature and by

keeping the flow of water through the system consistent.

It is not possible to contract Legionnaires disease by drinking or bathing in contaminated

water. The spores of the bacteria have to be airborne and breathed in to cause the

pneumonia associated with Legionnaires disease.

The PCT recognises its duty of care to its staff, patients and visitors and the responsibility

for the environment. Through this policy the PCT intends to carry out all activities in a

manner that demonstrates care for staff, patients, visitors and the environment whilst

continuing to provide the highest standards of healthcare.

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4. Responsibilities

4.1 Chief Executive and Board responsibilities

While ultimate responsibility is vested in the PCT Board, executive responsibility is

delegated to the Chief Executive for managing health and safety. Compliance with this

policy will be achieved by:

• Systematic identification and assessment of risk.

• Allocating appropriate resources to achieve reduction in risk, so far as is reasonable

practicable.

• Implementation of effective control measures.

The Health and Safety Executive Approved Code of Practice (L8) requires that one person

should be appointed as being responsible for over-seeing the assessment of risk

associated with Legionella. The Nurse Director is the Board Health and Safety Lead.

4.2 Director of Public Health Responsibilities

It is the Director of Public Health’s responsibility to lead the investigation group in

response to an out break of Legionellosis.

• The local authority and Health and Safety Executive have been alerted (if

required)

• The Chief Executive is kept informed of any Legionella risks and that they are

placed on the corporate risk register.

• A press statement is prepared and that media relations personnel are informed.

4.3 All Employees Responsibilities

Employee responsibilities under the Health and Safety at Work Act clearly state that

there is a duty on all employees to report hazards. This includes biological hazards and

therefore risks of Legionella. Staff are required to report to the Estates and Facilities

Manager immediately if they notice the following:

• Loss of temperature in the hot water system

• Any loss of pressure in either the hot water or cold water systems

• Any suspected cases of Legionnaires disease.

• A basin, bath or shower that is infrequently used.

To control the proliferation of Legionella bacteria, all staff are responsible for ensuring

that all outlets (taps and showers) are run once per week for a minimum period of 5

minutes.

4.4 Estates and Facilities Manager Responsibilities

The Estates and Facilities Manager is the Nominated Responsible Person for the PCT.

The responsibilities for the nominated responsible person are to ensure that:

• A Risk Assessment will be carried out by themselves and the maintenance

contractor if there are significant changes to a PCT site.

• A plan is produced of the PCT sites indicating those areas of the site where pipe

work is poor. The PCT will renew water pipe work when refurbishing areas.

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• Receive and review annual reports from the maintenance contractor, regarding the

results of the Planned Preventative Maintenance carried out as described in section

6 of this policy.

• Inform the Director of Public Health, Director of Infection Prevention Control (DIPC)

and the PCT Health and Safety Advisor immediately if any suspect Legionella

proliferation conditions are discovered.

• They are part of the incident control team in the event of suspect Legionella and to

maintain a log of the team’s meetings and actions.

• Ensure that an Incident Report is completed.

4.5 Health and Safety manager

• Shall supply advice and assistance in all safety matters

• If requested, participate in compliance audits

• Summarise reported incidents to safety committees

• Be a member of an incident control team

5 Water Temperatures and Legionella bacteria proliferation

Legionella pneumophila proliferation may occur in water systems where the temperature

is between 20 and 45 o C. It is uncommon to find proliferation below 20 o C, and it does

not survive for any lengthy period above 60 o C. The optimum laboratory temperature for

the growth of the bacterium is 37 o C.

The presence of any sediment, sludge, scale and organic material can act as a source of

nutrient for Legionella bacteria. Commonly encountered organisms in water systems

such as algae, amoebae and other bacteria may serve as a nutrient source for legionella.

The formation of a bio-film (slime) within a water system is thought to play an important

role in harbouring and providing favourable conditions in which Legionella can proliferate.

It therefore follows that clean water systems, devoid of sludge, slime and organic matter,

and operating at temperatures either less than 20 O C or greater than 60 o C will discourage

the proliferation of Legionella.

More detailed explanations of the following systems are included in Appendix 1

• Design and Installation of Building Services

• Cold Water Systems & Water Storage

• Disinfection of Water Storage Tanks

• Hot Water Systems & DHW Calorifiers

• Air Conditioning Systems and Air Handling Units

6 Intermittently/Infrequently used Outlets and Showers

The need for intermittently or infrequently used taps and appliances (particularly

showers) shall be reviewed from time to time, by the Estates and Facilities Manager and

the Maintenance firm/contractor.

If such taps and appliances are not necessary the supplies shall be terminated at source

by the removal of the tee and new pipe let in.

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Staff shall be responsible to ensure that if an appliance is not used on a daily basis then

it must be flushed for 5 minutes continuously once a week and a log kept of the dates

and which appliance/tap has been flushed (Appendix 5 – Copy log sheet to be filed in

Water Log Book, held centrally on site, when completed)

During temporary closure of wards/buildings a procedure for flushing the hot and cold

water services shall be implemented and recorded by the maintenance staff. This will

include opening all taps for a period of 5 minutes and flushing all WC cisterns on a

weekly cycle. On a quarterly basis showerheads and hoses will be dismantled, where

ever possible, cleaned and de-scaled and the work logged (as described in section 6 of

this policy). this work will be carried out by the Maintenance Contractor who will provide

reports to the Estates and Facilities Manager.

7 Monitoring and Record Keeping

All patient areas will be monitored. Water sampling will be arranged and supervised by

the Maintenance contractor, who will provide reports to the Estates and Facilities

Manager.

The flow temperature from DHW calorifiers or other DHW heaters should be not less

than 60 o C. The minimum temperature anywhere in the circulation pipe work should not

be less that 50 o C.

Water temperature at representative hot and cold outlets shall be measured and

recorded at least twice per year. Results should be recorded on a log sheet. All failures

and large variations must be reported and investigated.

Cold water outlet temperature shall be measured after allowing the water to run at full

flow for 1 minute. The temperature should be less than 20 o C. If the temperature is

found to be above 20 o C an investigation will be undertaken to find the cause, including

enquiry of the water supplier.

Hot water outlet temperatures shall be measured after allowing the water to run at full

flow for 1 minute. The temperature should be at least 50 o C. However where mixing or

blending devices are used which prevent the outlet reaching this temperature, the pipe

surface immediately before the device should reach 50 o C within 1 minute.

8 Planned Preventative Maintenance (PPM) Schedule

The following table lists frequency of tasks scheduled by the maintenance department as PPM.

JOB

Changeover of twin DHW Circulating pumps.

Changeover of twin pressurization set pumps.

Flushing taps etc of empty wards/departments.

Flushing and cleaning DHW calorifiers..

Checking ventilation system condensate

drains.

Check flow and return temperature at

calorifiers.

Clean/disinfecting of cold water storage tanks

FREQUENCY

Weekly

Weekly

Weekly

Annually

Monthly

Monthly

Annually

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Inspection/cleaning of ventilation cooling

batteries.

Sentinel points temperature testing.

Cleaning of shower heads.

Annually - April/May

Quarterly

Quarterly or as necessary.

Records shall be kept on file for a period of at least five years and will be included in the

annual report provided by the Maintenance contractor to the Estates and Facilities

Manager.

Any abnormal test results should be notified to the Estates and Facilities Manager

immediately, and any remedial works will be undertaken at the earliest possible

opportunity.

9 Control Methods

The PCT will adopt the following Control Methods to reduce the proliferation of

Legionella.

• Maintain Water temperature (at 60 o C out return of 55 o C)

supplies less than 20 o C.

• Removal of dead legs and modifications to area where growth may occur.

DHW+ cold water

• Water tanks shall be cleaned on a regular basis to remove sediment, sludge, scale

and organic material.

10 Action in the Event of a Suspected Outbreak or Incident.

The Director of Public Health (in conjunction with HPC) will lead the investigation into a

suspected outbreak or incident and will ensure the local authority and the HSE are

informed if relevant. If appropriate an incident control team may be convened comprising

of:-

• Director of Public Health

• Health Protection Agency (HPA)

• Director of Infection Prevention and Control (DIPC)

• Infection Control Nurse

• Maintenance Contractor

• Estates and Facilities Manager

• Manager of the affected Ward/Dept

PCT Health and Safety Manager

The group shall meet as necessary with others as appropriate to co-ordinate

investigation of the problem and progress any necessary action. Minutes are to be kept

and a log of actions taken and results of tests and Inspections are to be recorded by the

Estates and Facilities Manager and the Maintenance Contractor. Photographic records

are to be kept where appropriate.

The group shall keep the following informed of developments.

• Chief Executive

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• Director of Human Resources

• Communications Manager

• Director of Provider Services

Immediate action may include:-

• Stopping admissions to the Ward/department/site

• Consideration of early discharge/transfer of patients where applicable

• Sampling and testing water from hot and cold taps and showers in area concerned.

• Examination of ductwork of ventilation plant to area concerned, and sampling of

condensate drain water from ceiling coil(s).

• Sampling of water from DHW calorifiers serving wards/department.

• Isolation of any showers.

• Elevation of DHW temperatures to 55 – 60 o C at outlets, and placing of warning

notices of raised temperatures.

• Inspection of maintenance records for legionellosis preventative work.

• Disinfection of water services in accordance with BS6700.

• Inform Occupational Health of the Incident

• Screen staff that may have been affected.

Legionnaire’s disease is not a notifiable disease in England. However, a case of

Legionellosis may be notifiable under the Reporting of Injuries Diseases and Dangerous

Occurrences Regulations 1985 (RIDDOR).

The Health and Safety Executive may be involved in the investigation of an outbreak.

The results of any investigation undertaken by the incident control team shall be

discussed at the Infection Control Committee and the Risk Management Committee.

11 Further Information

This document sets out the policy of NHS North Somerset in respect of the design,

operation and maintenance of hot & cold water services so as to minimize the risk of

Legionnaire’s disease. Guidance is incorporated from the following documents.

• The control of Legionella in Health Care Premises DHS 1988.

• Control of Legionella and Safe Hot Water Temperatures HN(90)12, HN(FP)

(90) 6 D of H May 1990.

• Legionnaire’s Disease The Control of Legionella bacteria in water systems.

Approved Code of Practice and Guidance, Health and Safety Commission,

2000.

• HTM 2040

• HTM 2027

The above documents should be consulted for more comprehensive information and

guidance.

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Appendix 1

Design and Installation of Building Services

All new installations shall be designed so as to comply with the guidance listed in section

4.

Certain fittings and materials used in water systems may support bacterial or fungal

growth. Examples include Leather, some rubbers, jointing compounds and mastics,

wooded padding and certain plastics. The “Water Fittings and Materials Directory”

published by the Water Research Centre lists fittings and materials which are acceptable.

New installations and alterations to existing installations for the PCT shall incorporate

only those fittings and materials published as safe in the latest edition of the Water

Research Council directory.

Cold Water Systems & Storage Tanks

Cold water shall not be stored or distributed at temperatures above 20 o C.

Cold water system storage tanks shall be suitable for potable water (not drinking water),

easily cleaned, equipped with a close fitting cover and adequate drain valve, suitably

insulated to minimise heat gains, and having overflow pipes properly screened. Tanks

shall have take-off and entry points at opposite ends to ensure a flow through the tank.

When tanks are fitted in parallel they shall be operated with one tank in use and the other

tank isolated and drained. Tank capacity shall be such that under normal use complete

turnover takes less than 24 hours.

The layout of cold services and tanks should ensure that water in the system does not

gain heat. Tanks and pipe work should not be positioned close to heat sources or where

they could be affected by solar gain, unless they are effectively insulated

The condition of cold water storage tanks shall be checked annually and any remedial

work carried out. Where possible building management system computers (BMS) shall

log the Temperature of the water in DHW calorifiers (6). Where this is not possible water

storage temperatures should be measured and recorded quarterly.

Where cold water storage tanks are installed in parallel, the installation shall be operated

with one tank empty and drained and one tank in use. This is to avoid stagnation of the

contents of one or other tank to differing ball valve operating levels and to cover capacity.

Where water pressurization sets are equipped with twin pumps, the pump sets shall be

changed over from duty to standby at intervals not exceeding one week.

DHW systems (including the pump circulations systems) shall NOT be shut down

overnight or “out of hours”.

Water softeners (where fitted) - base exchange - will be backwashed weekly and periodic

cleaning and disinfections of the brine tank will be undertaken in accordance with

manufacturers/supplier’s instructions.

Stand-by storage systems will be drained when not in use and cleaned and disinfected

before being brought into service.

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Maintenance staff who have undertaken “dirty” jobs (ie unblocking drains or repairing

bed-pan washers) must change into clean protective clothing and wash hands thoroughly

before working on domestic hot or cold water systems where there is a risk of

contaminating that system.

Every year DHW calorifiers shall be thoroughly cleaned to remove sludge, loose debris

and scale.

Before any DHW calorifier is returned to service following temporary disuse or service, it

shall be refilled, drained, refilled again, and the entire contents brought up to and held at

a temperature of at least 60 o C for at least 1 hour. The calorifier should remain isolated

from the hot water supply system until this procedure is completed

Disinfection of Water Storage Tanks

According to the Approval Code of Practice and Guidance for the Prevention and Control

of Legionellosis, water services are only required to be cleaned and disinfected if

a. routine inspection shows it to be necessary or

b. if the system or any part of it has been substantially altered or entered for

maintenance purposes in a manner which may lead to contamination, or

c. During or following an outbreak or suspected outbreak of legionellosis.

Hot Water Systems & DHW Calorifiers

Calorifiers shall be capable of heating their contents to the required temperatures of 60 o C

throughout, and shall be readily accessible for cleaning. It shall be possible to isolate

them, and they shall incorporate drain connections at the lowest points which are large

enough to permit the removal of sludge and quick drainage of the vessel.

Calorifiers shall be fitted with non-return valves on the cold feed and also on the

circulation return. Both valves shall be within 300mm of the calorifiers. Pipework shall

be as short and direct as possible especially where it serves intermittently used taps and

appliances. On new systems, spurs from circulation loops shall not exceed 5 metres in

length.

DHW circulation pumps shall be of adequate performance to maintain a minimum return

temperature of 50 o C. DHW systems shall not be used for space, heating, and towel

rails, radiators etc shall not be fed from DHW systems. Where people are at risk of

scolding are served by the DHW system, “failsafe” thermostatically controlled mixing

valves (i.e. valves which are unaffected by changes in water pressure and automatically

close the hot water supply if the cold water fails) shall be used, positioned as close as

possible to the hot water outlets, to reduce the hot water temperature at the outlet to

43 o C. Those people at risk of scalding may include the very old and those with sensory

loss. Thermostatic Mixing Valves (TMVs) shall not be used with low volume spray taps.

NOTE Water Services shall be disinfected before being taken into use, to remove

contamination, which may have occurred during construction, in accordance with the

British Standards 6700 “Specification for the design installation, testing and maintenance

of services supplying water for domestic use within buildings and their cartilages”

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Air Conditioning Systems and Air Handling Units

Ventilation and air conditioning systems shall be designed so that water, whether from

the supply or from other sources such as condensation, cannot accumulate in ductwork

or plant, which is subject to an air stream. All condensation drains shall incorporate an

air break as near to the ventilation or air conditioning system as possible, to prevent

potentially contaminated water from being drawn back into the system. Procedure and

asset register held in maintenance.

Air handling unit cooling condensate drains shall be checked every month to ensure that

the glass trap is intact and topped- up with clean water, and most importantly to ensure

that the air break is intact.

Air handling Unit cooling batteries and drainage trays shall be inspected once per annum

during April/May before the cooling season gets under way. If a battery or tray is clean

and dry without corrosion, fouling or slime then no further action is necessary. Any

battery or tray suffering from corrosion, fouling or slime shall be thoroughly cleaned (if

possible using steam or high pressure hot water) and any exposed metalwork then

treated with protective paint.

No Domestic Type Air humidifiers or any similar equipment which may compromise air

quality shall be put into use on PCT premises without the prior approval of the Infection

Control Committee.

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Appendix 2

Legionnaire’s Disease

The Disease

Legionnaires Disease was the first recognized in July 1976, when an outbreak occurred

amongst delegates attending an American Legion Convention in Philadelphia. The cause

of the outbreak eluded scientists for several months, but in January 1977 the Centre for

Disease Control, Atlanta reported the isolation of the aetiological agent, which they

named Legionella pneumophila. Legionnaires’ disease is an infection with between

200 and 250 cases each year and in the UK being reported to the Communicable

Disease Surveillance Centre. Reporting is voluntary and is probable that in some cases

of Legionnaires’ disease are not detected or reported.

Legionnaires’ disease is a pneumonia caused by Legionella pneumophila. Infection is

believed to occur by inhalation of contaminated aerosols produced by, e.g. airconditioning,

cooling towers, showers, nebulizers, etc. The incubation period of the

disease is 2-10 days. Symptoms include; myalgia and headache followed by fever, chills

and a consolidating pneumonia, which primarily involve the alveoli and terminal

bronchioles; an intra-alveolar exudate is characteristic of the disease.

Other common symptoms include; chest and abdominal pains, vomiting, diarrhoea and

mental confusion. Mortality may be high, particularly in susceptible individuals (e.g. the

elderly, smokers, people with a history of bronchial disease, patients on

immunosuppressive drugs).

Most cases (75%) of Legionnaires’ disease are sporadic; the rest arise from outbreaks.

There are probably only a few hundred cases of the disease in the UK every year;

approximately 20 people die as a result of Legionella pneumonia annually. The number

of cases of non-Legionella pneumonias occurring annually in the UK (i.e. pneumonias

caused by other types of bacteria or by viruses) is measured in many tens of thousands,

of which several thousand results in mortalities. Legionnaires’ disease is therefore a rare

illness, but an important one in the eyes of the public and those responsible for the

operation of water systems, which can from time to time act as a source for the disease.

There is no evidence that the disease can be transmitted from person to person. It is not

known what number of aerosolized Legionella need to be inhaled by a susceptible

individual to cause an infection; different numbers may be required for different

Legionella strains, as some may be more virulent than others. It has been noted that,

amoeboid vesicles containing large numbers of viable Legionella might be the infective

agents, because the disease usually starts in one lung a few days before the other; if

free-floating cells are involved, both lungs would be expected to become infected

simultaneously. The bacterium is not highly virulent, but may affect individuals who are

especially susceptible. In most outbreaks less than 5 per cent of people exposed to the

source of infection have contracted Legionnaires’ disease although in some hospital

units, such as renal and oncology wards, greater attack rates have been reported.

General support measures can also assist the Legionnaires’ disease patient including:

relief of fever and myalgia with aspirin etc, chest physiotherapy/drainage, and prevention

of dehydration, adequate nutrition.

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Legionella – The known species

The diagnosis of Legionnaires’ disease is confirmed by culturing the organism from

clinical material such as sputum, bronchial washings or lung tissue. Alternatively a blood

test may be used which measures the presence of the specific antibody produced by the

body to combat the infection. Several days elapse before measurable levels of antibody

appear, so this serological test may not be helpful in identifying Legionnaires’ disease

in the early stages of the illness. L. pneumophila is one member of a large family of

Legionellaceae. Approx 40 other species of legionella have been reported and at least

sixteen serogroups of L. pneumophila have been described. L pneumophila serogroups

1 is the organism which is most commonly responsible for Legionnaires’ disease in

Britain but other serogroups of pneumophila and several other legionella species

occasionally cause pneumonia in humans. Members of the family Legionellaceae

including serogroup 1, are commonly found in water systems, both natural and manmade.

The bacterium is a common one, which survives, and multiplies in water. It is widespread

in natural fresh water including rivers, lakes, streams and ponds and may also be found

in wet soil. Airborne dispersal may occur when water droplets are created. There is a

strong likelihood of very low concentrations of the bacterial existing in all open water

system including those of building services.

The optimum temperature for multiplication of the bacteria in the laboratory is around

37 o C. At higher temperatures the rate of multiplication of legionellae in the laboratory

decreases and 46 o C multiplication ceases. The temperature at which the bacteria are

held may also have a bearing on the virulence; those held at 37 o C may have a greater

virulence than those held below 25 o C. The bacteria will survive at higher temperatures

but the survival time decreases from a matter of hours at 50 o C, to one of minutes at

60 o C; at 70 o C the organism is killed virtually instantaneously.

Below 37 o C the multiplication rate decreases and can be considered insignificant below

20 o C. The organism can become dormant at much lower temperatures and return to

active multiplication whenever more favorable conditions occur. It appears to be

insensitive to pH and has been found in cold water systems having a wide range of pH

values.

Two factors determine the number of bacteria deeply inhaled:

A) The concentration of bacteria in the air; this is determined both by the concentration of

bacteria in the water and the amount of contaminated water disposed into a given air

volume. The concentration of live bacteria in the air falls rapidly with distance from the

source. Where a cooling tower and the fresh air inlet to the building are both at roof level,

then it may be possible for contamination from the tower to reach the air inlet hence enter

the building. The quantity entering will depend primarily on the separation distance

between the tower and the fresh air inlet. Increasing the distance of separation and

location of the air inlet upwind the tower helps to reduce the likelihood of water droplets

containing legionellae from entering the building.

B) The duration of the exposure to the contaminated air; Exposure in a shower is usually

limited to a few minutes, while exposure in a spa is usually longer. Exposure to airborne

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legionellae distributed in a building from a cooling system may take place whenever the

tower is operating, which may be most of the day during the summer.

The risk increases with the number of legionella in the air and with the respiratory rate of

the individual, and the length of time the person is exposed. The chances of legionella

infection occurring increase with the number and susceptibility of people exposed. Of the

40 currently recognized species of Legionella, 16 have been shown to cause

Legionellosis; that is, they have been isolated from infected humans showing disease

symptoms. These known pathogenic species are listed below. Ten of them have been

isolated from various systems in-vitro. All serogroups of L. pneumophila are pathogenic,

although they appear to display differences in virulence. The general point to make is

that Legionella is a genus of pathogenic bacteria and that not too much importance

should be attached to the identity of particular species in a water system – the prime

objective should be to eliminate the organism from the system. So far only L. feeleii, L

pneumophila and L. anisa have been shown to cause Pontiac Fever. However, it is

reasonable to expect that other species can cause the disease under the appropriate

circumstances. Legionella bacteria also require a supply of nutrients to multiply. Sources

can include, for example, commonly occurring organisms such ass algae, amoeba and

other bacteria. The presence of sediment, sludge, scale and other material within the

system, together with biofilms, make for conditions favourable for the growth of legionella

bacteria A biofilm is a thin layer of micro-organisms which may form a slime on the

surfaces in contact with water.

Such biofilms, sludge and scale can protect legionella bacteria from temperature and

concentrations of biocide that would otherwise kill or inhibit these organisms if they were

freely suspended in the water.

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Appendix 3

Principal Legislation

ACOP Legionnaires Disease “The control of Legionella bacteria in water systems”

Approved code of practice and guidance L8

The ACOP L8 defines broad practical guidelines for compliance with the Health and

Safety at Work Act 1974 and the Control of Substances Hazardous to Health Regulations

1988 – COSHH. In particular it gives guidance on sections 2, 3, 4 and 6 (As amended by

the Consumer Protection Act 1987) of HWSA and Regulations 6,7,8,9 and 12 of

COSSHH. The code also gives guidance on compliance with the relevant parts of the

Management of Health and Safety at Work Regulations 1999 (MHSWR). This Code has

been approved by the Health and Safety Commission and gives advice on how to comply

with the Law. This Code has a special legal status. If you are prosecuted for breach of

health and safety law, and it is proved that you have not followed the relevant provisions

of the Code, a court will find you at fault, unless you can show that you have complied

with the law in some other way.

Health and Safety at Work etc. Act 1974 Sections 2, 3, 4 and 6 (As amended by the

Consumer Protection Act 1987)

Employers have a general duty, Under the Act, so far as is reasonably practicable to

ensure the health, safety and welfare of their employees and visitors. These duties are

legally enforceable, and the Health and Safety Executive have successfully prosecuted

occupiers of premises under this statute for outbreaks of Legionnaires’ disease. It falls

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. Failure to have proper system of work and adequate control measures can

also be an offence even though an outbreak has not occurred.

Control of Substances Hazardous to Health Regulations 1994 Regulation 6, 7, 8, 9

and 12 (COSHH)

These regulations apply to micro-organisms, including Legionella, which could create a

health hazard.

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 1998

These Regulations require that a proper officer (now usually the consultant in

communicable disease control (CCDC) shall inform the chief medical officer of any

serious outbreak of any disease which has, to his knowledge has occurred in his district.

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The Water Supply (Water Quality) Regulations 1989, Water Supply (Water Quality)

(Amendment) Regulations 1991

These regulations apply to water stored and distributed within any site, which is used for

drinking, and any domestic purpose.

The Private Water Supplies Regulations 1991 (Statutory Instrument no 2790) cover

private water supplies (Boreholes and Wells).

Food Act 1990

This Act covers water used for food preparation or food manufacture, and also includes

water used for drinking.

The Reporting of Injuries, Diseases and Dangerous Occurrences

Regulations 1995 (RIDDOR) require employers and others, egg the person who has

control of work premises, to report to HSE, accidents and some diseases that arise out of

or in connection with work activities. Cases of Legionellosis are reportable under

RIDDOR if a doctor notifies the employer and if the employees or others have been

exposed to a risk of inhalation of aerosols from cooling – towers or hot water systems

through use or work activity on such systems in a work place.

The Notification of Cooling Towers and Evaporative Condensers Regulations 1992

Those who have, to any extent, control of premises, have a duty under the Notification of

Cooling Towers and Evaporative Condensers Regulations 1992 to notify the Local

Authority in writing with details of “Notifiable Devices” these consist of cooling towers and

evaporative condensers, except when they contain water that is not exposed to the air

and the water and electricity supply are not connected. Although the requirement is to

notify the Local Authority, the regulations are enforced by the relevant authority for the

premises concerned. Forms are available from the Local Authorities or the Local HSE

Office. If a tower becomes redundant and is decommissioned or dismantled, this should

be notified. The main purpose of these regulations is to help in the investigation of

outbreaks.

The Safety Representatives and Safety Committees Regulations 1977 and the

Health and Safety (Consultation with Employees) Regulations 1996.

The Safety Representatives and Safety Committees Regulations 1977 and the Health

and Safety (Consultation with Employees) Regulations 1996. Require employers to

consult trade union safety representatives other employee’s representatives, or

employees where there are no representatives, about Health and Safety matters. This

includes changes to the work that may affect their Health and Safety at work,

arrangement for getting competent help, information on the risks and controls, and the

Planning of Health and Safety training.

The Water supply (Water Fittings) Regulations 1999.

These regulations relate to the appropriate design and methods installation of water

systems and the appropriate materials used on any water system.

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Management of Health and Safety at Work regulations 1999.

These regulations provide a broad framework for controlling health and safety at work.

They require the employer to have carried out risk assessments and to have access to

competent help in applying the provisions of health and safety law. They also require the

employer to establish procedures to be followed by any worker if situations presenting

serious and imminent danger were to arise; and for co-operation where two or more

employers or self-employed persons share a workplace.

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Appendix 4

Guidance

L8 Approved Code of Practice

Health and Safety Executive Approved Code of Practice L8, Legionnaires Disease “The

Control of Legionella Bacteria in Water Systems”, provides a detailed series of

requirements to enable a practitioner to comply with Health and Safety at Work Act 1974

and COSHH Regulations 1988.

The guidance is issued by the Health and Safety Executive. Following the guidance is

not compulsory and you are free to take other action. But if you do follow the guidance

you will normally be doing enough to comply with the law. Health and Safety inspectors

seek to secure compliance with the law and may refer to this guidance as illustrating

good practice. If you do not follow the guidance then you may be required by a court to

provide evidence of compliance in some other way.

Health Technical Memorandum 04-01 The Control of Legionella in Hygiene, “safe”

hot water, cold water and drinking water systems.

Health Technical Memorandum (HTM) 04-01 provides recommendations, advice and

guidance on controlling Legionella in healthcare premises. It is applicable to new and

existing sites, and is for use at various stages during the inception, design, upgrading,

refurbishment, extension and maintenance of a building.

HTM 04-01 in respect of the control of legionella bacteria focuses on:

a. Legal and mandatory requirements

b. Design of systems;

c. Maintenance of systems;

d. Operation of the relevant systems.

It sets out items calling for action. It cross-references to the Approved Code of Practice

(which should be consulted where any resolution of the intent is required) and indicates

suggested priorities for implementation.

It details the precaution, which can be employed to reduce and minimize the risks. These

precautions also include information on precautions, material selection, design and

construction, operation, inspection/maintenance, cleaning/disinfection and water

treatment. The A.C.O.P and Guidance L8 has been drawn up so to take into account

recent advances in the understanding of the Legionella organisms and how they grow

and proliferate. It also incorporates the findings of research, undertaken by the HSE and

others, which assesses alternative control strategies and explains how they may be used

effectively and safely. Conventionally a water temperature regime has is recommended

and has generally proved to be effective when there has been appropriate attention to

system parameters. However, it has sometimes been difficult to achieve and maintain the

hot and cold-water temperatures required, especially in some older buildings with water

systems. The temperature control strategy may also require the provision of the

thermostatic mixing valves if scalding is assessed as a significant risk.

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Recent research has shown that there are alternative water treatment technologies,

which can also be effective in controlling the growth of Legionella in the water system of

a building. However, these alternatives like the water temperature regime require

meticulous control in system parameters if they are to be effective. It is again important

to remember that the term ‘Legionellosis’ refers to any illness that may be contracted

through any Legionella organism.

Hot and cold water supply, storage and mains services – HTM 04-01

Health Technical Memorandum (HTM) 04-01 provides recommendations, advice and

guidance on the design, installation and maintenance of hot and coldwater distribution

systems in Healthcare premises. It is applicable to new and existing sites, and is for use

at various stages during the inception, design, upgrading, refurbishment, extension and

maintenance of a building.

HTM 04-01 focuses on:

a. Legal and mandatory requirements

b. Design of systems

c. Maintenance of systems;

d. Operation of systems.

Ventilation of healthcare premises – HTM 2025

Health and Technical Memorandum 2025 provides recommendations, advice and

guidance on the design, installation and maintenance of ventilation in all types of

healthcare premises.

HTM 2025 focuses on:

a. Legal and mandatory requirements

b. Design of systems;

c. Maintenance of systems;

d. Operation of systems.

It is published in four volumes, each addressing a separate discipline; these being,

Management Policy, Design Considerations, Validation and Verification and Operational

Management. It is applicable to new and existing sites, and is for use at various stages

during the inception, design, upgrading, refurbishment, extension and maintenance of a

building.

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Appendix 5

Flushing record sheet for infrequently used water outlets

• Flush all outlets including WC’s and showers once per week for 5 minutes

• When flushing showers minimise spray

Building………………………………

Location Date flushed Name comments

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