Domestic Water Systems Legionella Risk Assessment And ...

Domestic Water Systems

Legionella Risk Assessment

And

Survey Report

Client: Ministry Of Justice Water

Site: MOJ - BARNET COUNTY COURT [WTR] (MJ461426)

Address: MOJ - BARNET COUNTY COURT [WTR] REGENTS PARK ROAD N31BQ

Date of Survey: 12 March 2019

Risk Assessor: Adam Midson

Recommended Review Date: 12 March 2021

Document Checked by: Amy Wilding

Domestic Water Systems Legionella Risk Assessment and Survey Report

Client:Ministry Of Justice Water

Site: MOJ - BARNET COUNTY COURT [WTR] (MJ461426) 2 Date: 12 March 2019

CONTENTS

1 Introduction ......................................................................................................................................................... 4

1.1 ACoP (Fourth edition) and HSG274 .............................................................................................................. 4

1.2 BS8580 .......................................................................................................................................................... 6

1.3 Objectives ..................................................................................................................................................... 6

1.4 Understanding the risk assessment ............................................................................................................. 7

2 Site Summary ....................................................................................................................................................... 9

2.1 Site Water Systems Overview – Site and Building Description .................................................................... 9

2.1.1 Main building ........................................................................................................................................ 9

2.2 Areas of Non Assessment ........................................................................................................................... 11

2.3 Susceptibility of the Sites Population ......................................................................................................... 11

2.3.1 Main building ...................................................................................................................................... 11

2.4 Water Systems Management Chain ........................................................................................................... 12

3 Executive Summary ........................................................................................................................................... 13

3.1 Primary Concerns ....................................................................................................................................... 13

3.2 Secondary Concerns ................................................................................................................................... 14

4 Assessment of Legionella Risk ........................................................................................................................... 16

4.1 Water Systems Control Management ........................................................................................................ 17

4.2 Incoming Cold Water Supply ...................................................................................................................... 18

4.3 Cold Water Storage Tanks .......................................................................................................................... 20

4.4 Cold Water Distribution System ................................................................................................................. 22

4.5 Low Storage Volume Water Heaters .......................................................................................................... 24

4.6 High Storage Volume Water Heaters ......................................................................................................... 29

4.7 Combination Water Heaters ...................................................................................................................... 31

4.8 Closed Water Systems ................................................................................................................................ 45

5 Outlet Location and Temperature Register ....................................................................................................... 46

5.1 Main building.............................................................................................................................................. 46

6 Remedial Actions ............................................................................................................................................... 49

6.1 Site Management ....................................................................................................................................... 49

6.1.1 Very High Priority ................................................................................................................................ 49

6.1.2 High Priority ........................................................................................................................................ 50

6.1.3 Medium Priority .................................................................................................................................. 54

6.2 Main building.............................................................................................................................................. 54

6.2.1 Very High Priority ................................................................................................................................ 54

6.2.2 High Priority ........................................................................................................................................ 55

6.2.3 Medium Priority .................................................................................................................................. 88

7 Assessor Notes ................................................................................................................................................. 109

7.1 Main building............................................................................................................................................ 109




7.1.1 Assessor comments .......................................................................................................................... 109

8 Written Scheme of Control and Prevention .................................................................................................... 110

8.1 Water Systems Legionella Control Management ..................................................................................... 111

8.2 Incoming Cold Water Supply .................................................................................................................... 111

8.3 Cold Water Storage Tanks ........................................................................................................................ 112

8.4 Cold Water Distribution Systems ............................................................................................................. 112

8.5 Low Storage Volume Water Heaters and System .................................................................................... 113

8.6 High Storage Volume Water Heaters and System .................................................................................... 114

8.7 Combination Water Heaters and System ................................................................................................. 114

8.8 Closed Water Systems .............................................................................................................................. 115

9 Asset Register .................................................................................................................................................. 116

10 Domestic Water System Schematics ............................................................................................................. 119

10.1 Schematic Key ........................................................................................................................................ 121

11 Appendix: ....................................................................................................................................................... 122

11.1 Code of Conduct ..................................................................................................................................... 122

11.2 Assessor Experience and Qualification ................................................................................................... 123

11.3 Glossary of Terms ................................................................................................................................... 125




Preamble: Document Overview The contents within this document have undergone an overview exercise by Mitie, prior to distribution. This exercise is to ensure that the process of recording all findings during the survey, have been completed as per the requirements of the Mitie process guidelines.

1 INTRODUCTION

1.1 ACOP (FOURTH EDITION) AND HSG274

The latest version of Approved Code of Practice (ACOP) L8 (Fourth edition) and its associated guidance documents came into effect in 2013/2014. The ACoP sets out a requirement under the Health and Safety at Work Act (1974), and the Control of Substances Hazardous to Health (COSHH) regulations for the management and control of micro-organisms such as Legionella. The ACoP provides the legislation through which prosecution may be made under the Health and Safety at Work Act or COSHH legislation. Whilst failure to comply with the ACoP is not in itself an offence, evident contravention of such may be used in evidence as part of the prosecution case. The ACoP applies to any work undertaken, and to premises used in connection with a trade. All water systems should be considered, with the potential for both the growth of Legionella bacteria, and water dissemination to atmosphere being assessed. The responsibility for management and maintenance of a system should be defined with clear lines of communication and reporting imposed. A written scheme of control or prevention techniques should be applied to minimise the risk areas identified. Records are required to be kept on site at all times for the preceding five years. The key element from the ACoP is for a Risk Assessment to be carried out on water services liable to give conditions, which may promote the growth of Legionella bacteria and dissemination to atmosphere. Where the assessment demonstrates that there is no reasonably foreseeable risk, or that the risks are insignificant and unlikely to increase, no further assessment or measures are necessary. Where the assessment shows that there is a reasonably foreseeable risk; the use of water systems should be controlled or prevented so far as reasonably practicable from that risk. The written scheme created to minimise the risk should contain such information about the system as is necessary to control or prevent the risk of exposure to Legionella bacteria, including:- a) An up-to-date plan showing the basic layout of the system, including parts which are temporarily out of

use b) Identification of the system structure c) A description of the correct and safe operation d) The precautions to be taken. The written scheme should be managed and properly recorded. Legionella is the bacterium that causes Legionnaires’ disease. Of this bacterium, Legionella Pneumophila is the species most commonly associated with disease outbreaks. Legionnaires’ disease is identified as a pneumonia type of infection of the lower respiratory tract. The infection is most commonly acquired by the inhalation of airborne droplets or particles containing virulent Legionella bacteria. Exposure to Legionella can also cause a short feverish illness without pneumonia known as Pontiac fever or Lochgoilhead fever. Research and investigations indicate that the occurrence of Legionella contamination is greatest in; wet cooling towers, evaporative condensers, domestic hot and cold water systems, air washers, spa baths and other systems where water is agitated and re-circulated.




Sediment, scale and organic material present in water systems, can provide nutrients and give protection to Legionella. Legionella has been shown to colonise certain types of water fittings, pipe work and materials used in the construction of water systems. The presence of these materials may provide nutrients for Legionella and make eradication difficult. Other organisms in water systems such as other bacteria, amoeba and algae can provide a suitable habitat and nutrients in which Legionella can survive and multiply. The formation of bio-films within water systems is undesirable and may also provide harbourage and favourable conditions for Legionella growth. The presence of Legionella in bio-films and in enclosures within protozoa may protect the organisms from remedial measures employed to eradicate the organism. Legionella is most likely to proliferate in water systems that have temperatures between 20˚C and 45˚C. Human body temperature of approximately 37˚C is the ideal temperature for proliferation. Stagnant water within the above temperature range appears to provide the ideal conditions for proliferation of Legionella. Legionella will survive temperatures below 20˚C and between 45 and 50˚C, but it is considered to be in a dormant state with no growth activity. The bacterium does not survive temperatures maintained at 50˚C or above. For water samples collected and returned to the laboratory, Legionella Pneumophila is recovered by the propagation of the organism on a specially supplemented nutrient growth medium. Such samples are normally incubated at 36˚C +/-1 ºC. It may take up to 10 days for colonies of Legionella to appear. Legionella can be recognised by visual examination of the colonies, followed by a number of laboratory techniques to identify species and serogroup. Legionnaires’ disease is most commonly caused by the inhalation of water droplets contaminated with the Legionella bacteria. It is therefore important that systems susceptible to colonisation by Legionella, and which incorporate an appropriate means for creating and disseminating water droplets should be identified and the risk they present assessed. This identification and assessment is required by ACoP L8 (Fourth edition: 2013). The assessment must be completed for routine system operation and also for circumstances such as breakdown, abnormal operation, commissioning or other unusual circumstances. Once the assessment has been completed, a strategy can be prepared for preventing or controlling the risk. The strategy will be based on a sound knowledge of the varying levels of attention required by the differing risk sources within the building. The assessment takes account of:

A) The potential for the formation of an aerosol or respirable droplets. B) The condition of the water. C) Water temperature. D) The water turnover rate. E) The susceptibility of person(s) exposed to droplets. F) The population density exposed to droplets.

Water droplets can be created in various ways such as by spraying, bubbling and following impact onto hard surfaces. Large drops may be reduced to respirable size by further impact or evaporation. Smaller particles can remain airborne for long periods and will be carried on air currents; distances up to 6 Kilometres have been reported. In undertaking the Risk Assessment and drawing up precautions, particular attention must be paid to

situations where:

1) The population exposed contains a relatively high number of people susceptible to legionella. 2) The density of population is high and therefore the number of people at potential risk is high.

The Risk Assessment should be reviewed whenever there is a reason to believe that the original assessment

may no longer be valid. The original assessment may be compromised if:

1) It is not reviewed regularly 2) Changes are made to plant or water systems or its use




3) Changes are made to building use in which the water system is installed 4) New Information about risks or control measures becomes available 5) Results of checks indicate that control measures are no longer effective.

Once a risk has been identified and assessed, a written scheme should be prepared for preventing or

controlling it. The risk is heightened when conditions are not monitored and control of the system is lost,

thereby allowing Legionella bacteria to proliferate.

The written scheme should be implemented together with a planned preventative maintenance schedule, in

line with that contained within the general recommendations sections of this report. This will meet the

requirements of the HSC ACOP L8 (Fourth edition: 2013) and the associated HSG guidance documents.

1.2 BS8580

This British Standard gives recommendations and guidance on the assessment of the risk of Legionellosis

presented by artificial water systems. It is applicable to any undertaking involving a work activity or premises

controlled in connection with a trade, business or other undertaking where water is used or stored in

circumstances that could cause a reasonably foreseeable risk of exposure to legionellae and contracting

Legionellosis.

The standard is applicable to Risk Assessments being undertaken on premises, plant and systems for the first

time, and to review and audit where a previous assessment has been undertaken and where control measures

might have been implemented.

1.3 OBJECTIVES

The objective of this Risk Assessment is to ensure compliance with ACoP L8 (Fourth edition) and HSG274 as part of which the following shall be performed:- a) Identification and assessment of source of risk, b) Preparation of a written scheme for preventing, minimising and controlling the risk, Once completed, the Risk assessment requires reviewing regularly and, in any case, whenever there is reason to believe that the original assessment may no longer be valid. This assessment is carried out as part of the total “Management Systems Controls” package for the Site/Group and should not be carried out just to comply. By this, it is meant that a Risk Assessment should be carried out in order to allow the Site Management to qualify or instigate any remedial or on-going works, and in order to provide the responsible person with the necessary site information for setting up all action plans. All recommendations made in the Risk Assessment must be made with the specific requirements of the Site and must take into consideration manpower and budgeting considerations. The Report, together with the associated works specifications/procedures, contingency measures, Management Responsibilities and Site Logbooks, must be included in the Management and Procedures Manual. The following legislation and industrial guidance has been used for the performance of this survey: Health and Safety at Work Act 1974 – Sections 2, 3 and 4; Control of Substances Hazardous to Health (COSHH) Regulations 2002 and Amendment 2003; The Approved Code of Practice and Guidance on Regulations – Legionnaires’ disease ‘The Control of Legionella Bacteria in Water Systems’ L8 (Fourth edition); Legionnaires’ disease: Technical guidance Part 2: The control of legionella bacteria in hot and cold water systems; Legionnaires’ disease: Technical guidance Part 3: The control of legionella bacteria in other risk systems; British Standard BSEN 806-5: 2012 Specification for installations inside buildings conveying water for human consumption; BS 8558:2015 Guide to the design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages; Water Supply (Water Fittings) Regulations 1999 and Water Byelaws 2000, Scotland;




EC Directive relating to the Quality of Water Intended for Human Consumption (80/778/EEC); BS8580-1 :2019 Water quality – Risk assessments for Legionella control – Code of practice

Notes:

Miscellaneous systems - where assessed, the guidance within HSG 274 Part 3 is used. Otherwise, the system is detailed in the Areas of Non Assessment section of this report

The temperatures have been taken and recorded from all areas that were accessible to the assessor during the survey; however in larger complex buildings a representative number of temperatures may only be taken and recorded.

1.4 UNDERSTANDING THE RISK ASSESSMENT

This risk assessment has been carried out in order to ascertain the possible risk of contracting Legionellosis, including Legionnaires’ disease, from water systems and to produce a written scheme which will identify the maintenance activities required to control or prevent the risk from legionella, including any remedial works that may be required to improve upon the findings of this assessment. In addition, other health and safety risks have also been included within this report. The water systems throughout this building, unless otherwise stated, have been surveyed utilising the specific asset survey forms within section 3 of this assessment. Each question is answered and, depending upon the survey findings, a risk score is allocated utilising the matrix below. This matrix is designed to indicate possible risk or problematic areas within the assets or water systems. Multiple questions will be asked for all aspects of the water asset or services present on the site. The results from these questions will then be scored upon the risk of Legionella and/or other health and safety concerns. The key to this scoring is: KEY M = Medium Legionella Risk, completion 0 – 6 months upon receipt of this document or by

agreement H = High Legionella risk, completion 0 – 3 months upon receipt of this document or by

agreement VH = Very High risk, Immediate Action Required

Explanation of risk rating Very Low and Low risk will conform to water systems or persons where all conditions are compliant with ACoP L8 Fourth edition and HSG274 and are quantifiable on Surveyors experience and knowledge. All PPM (preventative planned maintenance) and tasks outlined within the written scheme and also any other recommendations outlined within the assessor notes section of this report should be followed Medium risk is where conditions, if not addressed or PPM (preventative planned maintenance)tasks are not completed within the required time schedule from receipt of receiving this document, but presents no immediate threat to health and safety, which are quantifiable on the surveyors experience and knowledge. High risk is where proliferation, dissemination are likely; where PPM (preventative planned maintenance) tasks have not been implemented or carried out correctly and conditions could support legionella proliferation. Where legionella management and training is insufficient or lines of communication are not established or any other health and safety issues identified which are quantifiable on the surveyors experience and knowledge. Very high risk is where an immediate risk to health and safety has been identified during the survey; these risks raised include, conditions that could support legionella proliferation and general health and safety concerns




which are quantifiable on the surveyors experience and knowledge. Such risks would be identified and reported prior to this document being written and distributed as required within BS8580:2010 and should therefore, be actioned immediately. In performing this assessment, areas, water assets and services made available to the assessor have been included and assessed. Known areas, water assets and services not made available to the assessor for assessing will be listed within the Areas of Non Assessment section of this assessment The assessor will use the knowledge of others as well as his own technical knowledge in the judgement of the water systems assessed within this document. If areas within the building cannot be fully assessed, due to access or operational limitations, then these details will be recorded within the appropriate survey sections of this assessment. In accordance with ACoP L8 (Fourth edition: 2013) this Risk Assessment must be reviewed regularly and/or whenever there is reason to believe that the original assessment may no longer be valid. We cannot guarantee that all pipe work passing underground or through floors, walls and ceilings has been traced, and it is possible that certain system dead-ends or dead-legs may not have been identified. As a result, the schematic diagram(s) contained within this report only details the visible or assumed pipe work. Whilst every effort has been made to ensure the accuracy of the content of this document, Mitie will accept no responsibility for any omissions that are not included within this document.




2 SITE SUMMARY

This report relates to the Legionella Risk Assessment and Water Hygiene Survey carried out at MOJ - BARNET COUNTY COURT [WTR]. The survey was conducted by Adam Midson of Mitie on 12 March 2019 on behalf of the Duty Holder, however this person was not identified at the time of survey. This Risk Assessment only covers those water systems identified and made accessible to the assessor at the time of survey by Qamar Kahn .

2.1 SITE WATER SYSTEMS OVERVIEW – SITE AND BUILDING

DESCRIPTION

The site contains 1 building with water services within it. This assessment relates to the domestic water services within MOJ - BARNET COUNTY COURT [WTR] only.

2.1.1 Main building

Main building is a 4 storey building used for County Courts and offices..

The number of people typically employed/present within this building is approximately 150. In addition, there

are a varying number of other visitors/contractors to the building each day when the overall figure will

increase.

The building is occupied daily 08.00-18.00 Monday to Saturday .

Building Water Services Summary:

Description of Incoming Cold Water Supply:

The incoming mains MCW01 enters the building in an unknown location and supplies all water heaters, kitchen

and cleaners areas as well as cold water storage tank CWST01 and heating pressurisation unit HPU01 in the

plant room.

Description of Cold Water Distribution System and CWSTs:

There is a cold water storage tank CWST01 in the plant room which supplies CWDS01 to all toilet areas

throughout.

Description of Hot Water System & Storage Vessels:

None present.

Description of Water Heaters, where present:

There is a mixture of low and high and storage volume water heaters as well as combination water heaters.

Description of TMVs, where present:

None present.

Description of Showers, where present:

None present.

Description of Tap Outlets, where present:

Tap outlets are heavily scaled and have tap inserts fitted sporadically throughout the building.

Description of any Closed Water Systems present:




There is a heating boiler in the plant room which is supplied by a heating pressurisation unit HPU01.

Description of any other miscellaneous water systems:

None present.




2.2 AREAS OF NON ASSESSMENT

The following areas of the site have not been assessed. Reasons are given for the non-assessment.

Location Notes

Main building : Ground : Medical Room

No assets exist now

2.3 SUSCEPTIBILITY OF THE SITES POPULATION

The susceptibility of personnel upon this site to the cause and effects of Legionnaires’ disease have been assessed within the known range for specific legionella susceptibility. Understandably, not every person has been interviewed to their susceptibility. Therefore assumptions have been made as appropriate, based upon visual observations and communication during this assessment.

2.3.1 Main building

Q General Information Comments

1 What is the typical number of people employed/present in the building, taking into account peak levels?

150

2 Does the building have a water system which may affect the public outside the premises?

No

3 Has a recorded case of Legionnaire's disease been associated with this building or associated water system(s)?

No

4 Does the building population include persons of high susceptibility, i.e. persons over the age of 45, heavy smokers, low immuno-suppression system?

Yes

5 State the assessed susceptibility of the building population to legionella bacteria:

Medium




2.4 WATER SYSTEMS MANAGEMENT CHAIN

Duty of Care Holder:

Appoint a responsible person for the control of legionella. This should be a manager, director or have sufficient

authority, competence and knowledge to bring about effective control of water systems. State the individual and/or

company who holds the ultimate responsibility for the correct operation as under ACoP L8 (Fourth edition: 2013) of the

water systems upon the site.

Name: Dawn Frost

Title: Account Director

Contact Details: Email: T: M: 07917751385

Nominated Responsible Person:

This person has the responsibility to ensure that personnel and contractors involved in performing the regime are

competent to do so. This person has the responsibility to ensure that all control and prevention works are completed

adequately. This person has the responsibility to maintain and keep all the records. State the individual to whom the

overall responsibility has been delegated by the Duty Holder.

Name: Ken Venables

Title: Property Asset Management


Water Treatment Contractor:

State the company who has been nominated to perform specialist contracted services as in accordance with the

requirements of ACoP L8 (Fourth edition: 2013) to the water systems upon this site.

Company: Mitie Water

Name: Ashley Lowry

Title

Contact Details: Email: T: 01252836800 M: 07552288730

Mechanical Maintenance Contractor:

State the company who have been nominated to perform specialist mechanical services, which will have a bearing on

the water systems upon the site.

Company: Mitie TFS

Name: Mathew Chalk

Title


Independent Consultant:

State the Company who have been nominated to perform specialist consultancy services, which will have a bearing on

the water system management upon the site.

Name:

Title:

Contact Details: Email: T: M:




3 EXECUTIVE SUMMARY

3.1 PRIMARY CONCERNS

These issues have been identified as very high or high risk and are detailed in the Remedial Actions section of this Risk Assessment. The corresponding remedial actions and / or controls should be implemented at the earliest opportunity.

It is considered that some of the named persons with responsibilities for water safety have not received appropriate training.

There are dead ends visibly present on this system. Photo 01 is in the plant room and is 15mm copper by 3cm on 15mm source pipework. Photo 02 is outside cleaners, Photo 03 is a 15mm x 500mm dead end in waiting room on first floor by cleaners.

There are dead ends visibly present on this system. Photo 01 is behind courtroom 8 toilet 15mm x 6cm on 28mm source pipework. Photo 02 is in

area B library void, 28mm x 600mm on 28m source pipework, photo 01 is on same piece of pipework.

There are dead legs visibly present on this system. The dead leg is in the second floor Cleaners Cupboard 15mm x 6cm copper.

Flexible hoses identified in this system do not conform to the water regulations advisory scheme (WRAS).

Flexible hoses identified in this system do not or could not be proven to conform to the water regulations advisory scheme (WRAS).

There are infrequently used outlets on this system. Photo 01 2 x wash hand basins in first floor gents toilet.

There are infrequently used outlets on this system. Photo 01 is second floor cleaners.

No valid calibration certificates was available for thermometers used to carry out site water monitoring.

Employees and representatives have not been consulted and informed about the potential of exposure to the legionella bacteria within the water systems.

Some remedial actions given in the previous risk assessment have not been carried out. There are still.some incorrectly installed expansion vessels, Dead ends, dead legs, Scaled outlets, Low flow temperatures from some water heaters, no domestic supply flushing records to LPHW01, non Wras flexi hoses present, no expansion vessel flushing records.

The closed system fast fill connection was seen to be left connected to the domestic supply system on the heating pressurisation unit HPU01, If left connected; the connection presents a contamination risk should the system back-syphon, drawing in the water from the closed system to the main domestic supply.

There was no evidence of a suitable staff training programme in place.

This unit and outlets supplied by the heater are considered to be infrequently used.

This unit and outlets supplied by the heater are considered to be infrequently used. Tap handles have been removed on two of the three mixer taps.

The CWST lid is not fixed and tight fitting. The lid is missing its locking screw.

The CWST lid is not fixed and tight fitting. The tank has bowed with temperature change and the locking screw has not been inserted so there now is an open hole in the lid.

The CWST lid is not fixed and tight fitting. The unit has warped with temperature changed and no locking screw for the lid has been put in.

The CWST lid is not fixed and tight fitting. There is no lid attached to the unit.

The CWST lid is not fixed and tight fitting. There is no lid fitted at all.

The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently 13.1 Degrees.

The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently 37.7




The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently no heating to the unit.

Some hot water temperatures recorded on this system were below 50°C . Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2). The water heater is currently isolated and not used.

Some or all hot water temperatures recorded on this system were below 50°C (55°C in healthcare). Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2).

Some or all hot water temperatures recorded on this system were below 50°C. Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2).

There are no suitable and sufficient water systems monitoring programme in place. There is no records of expansion vessel flushing, no descaling regime implemented, no inline filter and softener service records.

Scale was visible on tap outlets.

Scale/debris was visible on tap outlets.

The domestic cold water supplying the closed system is not regularly flushed. Due to the nature of the closed system, the water is only pulled through the pipework as and when required. This pipework, in effect, acts as a system dead-leg. Dead-legs are prone to stagnation.

Inspection of the following tanks has shown that moderate internal contamination is evident. Contamination within the tanks is ideal to encourage microbial activity and legionella proliferation. This is detailed within HSG274 (Part 2). To combat this issue, the tanks should undergo a full deep clean and disinfection.

3.2 SECONDARY CONCERNS

These issues have been identified as medium risk and are detailed in the Remedial Actions section of this Risk Assessment. The corresponding remedial actions and / or controls should be implemented at the earliest opportunity.

There are sections of pipework that were seen to not be suitably insulated.

All or some expansion/pressure vessels were found not to be installed correctly. Photo 01 is in staff

kitchen.

There is not an appropriate servicing and maintenance regime in place for inline filters.

All or some expansion/pressure vessels are not approved against BS:6920.

No records or not all monitoring records from the previous 5 years are available.

Flexible hoses identified in the cold water system do not conform to the water regulations advisory

scheme (WRAS).

Additional drain valves are required to be fitted to all/some expansion/pressure vessels. Photo 01

is in staff kitchen, Photo 02 is in store room.

There are taps with spray or other inserts present.

Expansion/pressure vessels do not undergo routine inspection and/or no maintenance records

were present.

A suitable lid vent is not present. It is necessary for the integral cold water storage tank to breathe

as the water level rises and falls. This is detailed in the Water Supply (Water Fittings) Regulations

1999 or Scottish Water Byelaws 2004. There is no lid for a vent to be attached to.



1999 or Scottish Water Byelaws 2004. There is no lid to attach a vent to.






1999 or Scottish Water Byelaws 2004. There is no lid vent present just a hole where one should be.




4 ASSESSMENT OF LEGIONELLA RISK

Within this section are survey forms for water system management and all water systems. From the questions in all survey forms any remedial works that are required are advised within the Remedial Actions section of this document. Any other recommendations considered to be a very low or low risk are advised within the assessor’s notes section of this report. The Written Scheme of Control and Prevention described in Section 8 is advised to be adopted, for the control and prevention of Legionnaires’ disease upon the water systems The following key is used in answering all questions of each survey report: KEY M = Medium Legionella Risk, completion 0 – 6 months upon receipt of this document or by

agreement H = High Legionella risk, completion 0 – 3 months upon receipt of this document or by agreement VH = Very High risk, Immediate Action Required




4.1 WATER SYSTEMS CONTROL MANAGEMENT

Q General information on Management

Scheme Comment Risk

1 Has a Water Risk Assessment been carried out previously?

A previous water risk assessment has been carried out, and this document is available to

view on the intranet.

2 Have all remedial actions given on the previous WRA been completed and signed off?

No H

3 Is there a suitable site Logbook containing records for the water services?

Yes

4 Where is the site logbook located? Office

5 Are all current monitoring and inspection records complete and up to date?

Yes

6 Are monitoring and inspection records available for the last 5 years?

No M

7 Is there a suitable written scheme of control? Yes

8 Are roles and responsibilities of the written scheme of control clearly defined?

Yes

9 Is there a preventative management structure?

Yes

10 Is this management structure complete and up to date?

Yes

11 Are all persons responsible for the management of the water systems suitably trained?

No H

12 Is evidence of appropriate staff training available?

No H

13 Is there a basic, suitable and sufficient system schematic diagram?

Yes

14 Are there action procedures in the event of any non-conformances?

Yes

15

Does the site have an action plan for Legionella positive results and emergency procedures in place if Legionnaire’s disease is associated with the building?

Yes

16 Are any site water services supplied by a third party, such as a landlord?

No

17

Is there a suitable and sufficient monitoring programme in place compliant to the ACoP L8 (Fourth edition) and HSG274 Part 2requirements?

No H

18 Are valid calibration certificates available for all thermometers used to carry out site temperature monitoring?

No H

19

Have all employees, or their representatives, been consulted and given information about the potential risks of exposure to the Legionella bacteria within the buildings water systems?

No H




4.2 INCOMING COLD WATER SUPPLY

AssetID MCW01

Q General Information Comment Risk

1 State the location of the main isolation valve: Not Found

2 Is there a water meter installed? N/A

3 Is all pipework correctly labelled? N/A

4 Is there sufficient safe access to all areas supplied by this system? N/A

5 State the source of the cold water supply to the building: MAINS

6 State the materials of construction of this supply: COPPER

7 Are flexible hoses fitted to any services on the cold water system? Yes

8 Are all flexi hoses correctly installed? i.e. no kinks Yes

9 Are there any flexi hoses that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory?

Yes H

10 Do all other materials and fittings visibly present on any services associated with this system conform to the Water Regulations Advisory Scheme (WRAS) directory?

Yes

11 Is temperature used as a control method? Yes

12 Are other control methods used? i.e. Chlorine dioxide, Ionisation etc. N/A

13 State the temperature of the outlet nearest to the incoming supply: 7.6

14 Is the temperature of the supply below 20°C? Yes

15 State the temperature of the outlet furthest from the incoming supply: 8.5

16 Is the temperature of the supply below 20°C? Yes

17 Are all other distribution temperatures that were tested within the correct temperature range? i.e. Below 20°C

Yes

18 Are any strainers fitted within the system? No

19 Are suitable backflow prevention devices or arrangements fitted to all relevant services appropriate to the fluid risk category advised in the water supply (water fittings) 1999?

Yes

20 Are any RPZ (reduced pressure zone valves) fitted to this cold water system? No

21 Does the cold water supply have any inline filters including scale inhibitors? Yes

22 Are all inline filters serviced and maintained with a suitable regime? No M

23 Are there any expansion/pressure vessels installed? Yes

24 Are all expansion/pressure vessels correctly installed? I.e. in a vertical position? No M

25 Do expansion/pressure vessels undergo routine inspection and maintenance? If Yes, was documentation presented for audit?

No M

26 Are expansion/pressure vessel internal bladders, diaphragms approved against BS:6920?

No M

27 Do any expansion vessels require additional drain valves fitted? Yes M

28 Are any dead legs visibly present on the cold water supply system? Yes H

29 Are any dead ends visibly present on the cold water supply system? Yes H

30 Are there any infrequently used outlets/services evident on the cold water system? Yes H




31 Is any unused equipment connected to the cold water system? No

32 Is there any visible scale/debris present on any of the tap outlets? Yes H

33 Do any tap outlets have any spray or other inserts fitted? Yes M

34 Are all areas of visible pipework suitably insulated? No M




4.3 COLD WATER STORAGE TANKS

AssetID CWST01


1 Loft hatch access size, if present: Door Way

2 CWST tank external dimensions: 2.5m x 2m x

2m

3 Is the tank suitably labelled? Yes

4 Inlet size: 54mm

5 Outlet size: 54mm

6 Overflow size: 64mm

7 Warning pipe size: 28mm

8 CWST drain size: 54mm

9 Is a foul drain nearby? Yes

10 Location of foul drain: Plant Room

11 Is a suitable power supply located nearby? Yes

12 Location of power supply: Plant Room

13 Is there sufficient safe access to the CWST? Yes

14 Is there suitable, sufficient and safe access to the CWST to carry out regular maintenance tasks? i.e. internal inspections, cleaning etc.

Yes

15 State the CWST materials of construction: GRP

16 State the source of the CWST water supply: MAINS

17 State the CWST method of construction: GOOD

18 Does the method of construction create areas of stagnation? I.e. hollow tube supports

No

19 State the actual volume of stored water: 10 000 Litres

20 Is the tank considered to be over-capacitated? No

21 Is the whole capacity of stored water turned over within 24 hours? Yes

22 State the ambient air temperature around the CWST (degC): 10.3

23 Is the ambient temperature around the CWST less then 20°C? Yes

24 State the ball valve inlet water temperature: 8.5

25 Is the ball valve inlet water temperature below 20°C? Yes

26 State the water temperature within the CWST: 9.3

27 Is the water temperature within the CWST below 20°C? Yes

28 State the water clarity within the CWST: GOOD

29 What is the level of debris/sediment within the CWST? LIGHT

30 Is any bacterial biofilm evident on the internal surface or walls? No

31 Is the CWST fitted with a lid? Yes

32 Is the CWST lid of a suitable material? Yes

33 Is the CWST lid fixed and tight fitting? Yes




34 Is there a suitable vent fitted to the tank/lid? Yes

35 Is there adequate cross-flow within the tank? I.e. inlet opposed from outlet Yes

36 Is the CWST linked to another tank? No

37 Is the CWST sufficiently insulated? Yes

38 Do all other materials and fittings visibly present on this tank conform to the Water Regulations Advisory Scheme (WRAS) directory?

Yes

39 Does the warning pipe or overflow have screens fitted? Yes

40 Is the CWST inspected in accordance with HSG274 Part 2? Yes

41 What is the condition of the internal tanks coating/lining? GOOD

42 Does the CWST require replacing with a new more suitable CWST? No

43 Does an expansion pipe from a hot water storage vessel or LPHW system return to the CWST?

No




4.4 COLD WATER DISTRIBUTION SYSTEM

AssetID CWDS01


1 Is all pipework correctly labelled? Yes

2 Is there sufficient safe access to all areas supplied by this system? Yes

3 Is temperature used as a control method? Yes

4 Are other control methods used? ie Chlorine dioxide, Ionisation etc. N/A

5 State which CWST is supplying this system: CWST01

6 Is the supply CWST in a compliant condition? Yes

7 State the temperature of the outlet nearest to the CWST: 9.5

8 Is the temperature of the outlet below 20°C? Yes

9 State the temperature of the outlet furthest from the CWST: 10.3

10 Is the temperature of the outlet below 20°C? Yes

11 Are all other distribution temperatures that were tested within the correct temperature range? i.e. Below 20°C

Yes

12 State the materials of construction of the cold water pipework: COPPER

13 Are flexible hoses fitted to any services on the cold water system? Yes

14 Are all flexi hoses correctly installed? ie no kinks Yes


Yes H

16 Do all other materials or fittings visibly present on any services associated with this system conform to the Water Regulations Advisory Scheme (WRAS) directory?

Yes

17 Are all areas of visible pipework suitably insulated? No M


19 Are suitable backflow prevention devices or arrangements fitted to all relevant services appropriate to the fluid risk category advised in the water supply (water fittings) 1999?

Yes

20 Are any RPZ (reduced pressure zone valves) fitted to this cold water system? No

21 Does the cold water supply have any inline filters including scale inhibitors? No

22 Are any dead legs visibly present on the cold water system? No

23 Are any dead ends visibly present on the cold water system? Yes H

24 Are there any infrequently used outlets/services evident on the cold water system? Yes H

25 Is any unused equipment connected to the cold water system? No



28 If booster pumps are fitted, is there a duty/standby arrangement which isn't alternated?

N/A

29 Are there any expansion/pressure vessels installed? No

30 Does this system require disinfecting? No




4.5 LOW STORAGE VOLUME WATER HEATERS

AssetID LSWH01


1 State the water capacity of the unit: 15 Litres

2 Is the unit vented or unvented? VENTED

3 Is there sufficient safe access to the water heater? Yes


5 State the source of the cold water supply to the water heater: MAINS

6 Is the water temperature above 50°C (55°C in healthcare) at all outlets that were tested?

Yes

7 Is the unit suitably insulated? Yes

8 State the materials of construction of the hot water pipework: COPPER

9 Are flexible hoses fitted to any services supplied by this heater? Yes



Yes H


Yes


14 Is the heater, or any other outlets supplied by this heater, infrequently used? No

15 Are any dead legs visibly present on this system? No

16 Are any dead ends visibly present on this system? No



19 Are TMV’s fitted to any services on this system? No




AssetID LSWH02








No H



9 Are flexible hoses fitted to any services supplied by this heater? No


Yes


12 Is the heater, or any other outlets supplied by this heater, infrequently used? Yes H




16 Do any tap outlets have any spray or other inserts fitted? No





AssetID LSWH03








Yes





Yes






16 Do any tap outlets have any spray or other inserts fitted? No





AssetID LSWH04








Yes






Yes H


Yes











AssetID LSWH05








Yes





Yes











4.6 HIGH STORAGE VOLUME WATER HEATERS

AssetID HSWH01






5 Is the stored water capacity of the unit excessive? No


7 State the unit's stored water temperature (°C): 0

8 Is the stored water temperature maintained at least 55-60°C? N/A


N/A






Yes H


Yes


17 Is the heater, or any other outlets supplied by this heater, infrequently used? Yes H









AssetID HSWH02






5 Is the stored water capacity of the unit excessive? No


7 State the unit's stored water temperature (°C): 57.9

8 Is the stored water temperature maintained at least 55-60°C? Yes


Yes





Yes











4.7 COMBINATION WATER HEATERS

AssetID CWH01


1 State the capacity of the integral CWST: 13 Litres

2 State the capacity of the heater: 50 Litres

3 State inlet size: 15mm

4 State outlet size: 22mm

5 State overflow size: 22mm


7 Is there suitable, sufficient and safe access to the integral CWST to carry out regular maintenance tasks? I.e. internal inspections, cleaning etc.

Yes

8 Is there sufficient safe access to all areas supplied by this heater? Yes


10 State the temperature of the cold water supply to the unit: 8.4

11 Is the temperature of the cold water supplying the unit below 20°C? Yes

12 State the water clarity within the integral CWST: GOOD

13 What is the level of debris/sediment within the integral CWST? LIGHT

14 Is the integral CWST lid fixed and tight fitting? No H

15 Is there a suitable vent fitted to the CWST lid? Yes




19 Is the stored water temperature maintained at least 55 - 60°C? Yes


Yes






Yes M


Yes










AssetID CWH02









Yes






13 What is the level of debris/sediment within the integral CWST? MODERATE H








Yes






Yes M


Yes











AssetID CWH03









Yes






13 What is the level of debris/sediment within the integral CWST? CLEAN

14 Is the integral CWST lid fixed and tight fitting? Yes





19 Is the stored water temperature maintained at least 55 - 60°C? No H


No H





Yes











AssetID CWH04









Yes






13 What is the level of debris/sediment within the integral CWST? LIGHT


15 Is there a suitable vent fitted to the CWST lid? No M






Yes






Yes M


Yes











AssetID CWH05









Yes














Yes






Yes M


Yes











AssetID CWH07









Yes














No H





Yes











AssetID CWH06









Yes














No H






Yes M


Yes











4.8 CLOSED WATER SYSTEMS

AssetID LPHW01


1 State the system description, i.e. LPHW, CHILLED, MPHW: LPHW

2 State the cold water supply source to this system: HPU01

3 How does the cold source supply this system? PRESSURE

4 State the location of the cold water supply source to this system: Plant Room

5 Is there a suitable flushing point on the domestic cold water supply? Yes

6 Is there evidence that the domestic water supply pipework is flushed regularly? No H

7 If fitted, have the fast fill connections been disconnected? No H




5 OUTLET LOCATION AND TEMPERATURE REGISTER

The table below only includes areas identified to the assessor at the time of survey.

5.1 MAIN BUILDING

Floor Location

Sentinel Points:

(N) = Nearest (F)= Furthest (M) = Multi Hot Water

System

Hot Taps No:

Cold Water System

Cold Taps No:

Hot / Cold

Mixer Taps No:

Showers No:

TMV/ Integrated

TMV’S No:

TMV Hot Inlet Temp ˚C

Hot Outlet Temp ˚C

Blended Temp

˚C

Cold Temp ˚C

Tap Inserts/ Sprays Present

?

Scaled/ Dirty

Outlets Present

?

Infrequently Used

Outlets Present

Non-Wras Flexi hose

No:

Hot Cold

3rd Floor Plant Room

0 0 0 0 0

0

2nd Floor Cleaners N None

LSWH02

1 MCW01 2 0 0 0 0 0

0 8.3 Yes Yes Yes 0

2nd Floor Ladies Toilet

N N LSWH0

1 0 CWDS01 0 4 0 0 0

63.6 0 9.6 Yes Yes No 6

2nd Floor Gents Toilet

N None

CWH01 0 CWDS01 0 4 0 0 0 56.9

0 10.0 Yes Yes No 8

2nd Floor

Judges Chambers

WC N

None

CWH03 0 CWDS01 0 1 0 0 0 37.3

0 10.1 Yes Yes No 0

2nd Floor

Magistrates Retiring

Room 0 0 0 0 0

0

2nd Floor WC None

None

CWH03 0 CWDS01 0 1 0 0 0 38.3

0 10.0 Yes Yes No 0

2nd Floor Kitchen F F CWH03 0 MCW01 0 1 0 0 0 38.3 0 8.5 Yes Yes No 2

2nd Floor Waiting

Area 0 0 0 0 0

0




1st Floor Ladies Toilet

N None

CWH02 0 CWDS01 0 3 0 0 0 68.9

0 9.7 Yes Yes No 4

1st Floor Gents Toilet

N None

HSWH01

0 CWDS01 0 3 0 0 0 21.3

0 0 Yes Yes Yes 4

1st Floor Cleaners N None

LSWH03

1 MCW01 2 0 0 0 0 62.3

0 8.3 Yes Yes No 1

1st Floor

Judges Chambers

1 N

None

HSWH02

0 CWDS01 0 1 0 0 0 57.9

0 10.3 Yes Yes No 0

1st Floor Court 8 WC N None

CWH06 0 CWDS01 0 1 0 0 0 13.1

0 9.9 Yes Yes No 2

1st Floor Courtroom

6 WC N

None

CWH07 0 CWDS01 0 1 0 0 0 12.3

0 10.3 Yes Yes No 0

1st Floor Court

room 5 WC F

None

HSWH02

0 CWDS01 0 1 0 0 0 58.1

0 10.5 Yes Yes No 0

1st Floor Courtroom

WC 7 F

None

CWH07 0 CWDS01 0 1 0 0 0 12.3

0 10.3 Yes Yes No 0

1st Floor Waiting

Area 0 0 0 0 0

0

1st Floor Area B library

0 0 0 0 0

0

Ground Gents Toilet

N F CWH05 0 CWDS01 0 4 0 0 0 61.7

0 10.4 Yes Yes No 4

Ground Ladies Toilet

N None

CWH04 0 CWDS01 0 4 0 0 0 63.4

0 10.3 Yes Yes No 6

Ground Staff

kitchen N

None

LSWH04

0 MCW01 0 1 0 0 0 60.4

0 7.8 Yes Yes No 6

Ground Bailiffs Kitchen

N None

LSWH05

0 MCW01 0 1 0 0 0 52.4

0 7.4 Yes Yes No 0

Ground Medical Room

None

None

0 0 1 0 0

0

Ground Cleaners None

N None 0 MCW01 1 0 0 0 0 0

0 7.3 No Yes No 0

Ground Store Room

0 0 0 0 0

0




6 REMEDIAL ACTIONS

From the information gained during the assessment, it is concluded that the sites water services and management of legionella risk conditions have areas in need of improvement to achieve the requirements of ACoP L8 (Fourth edition) and HSG 274 Part 2. The remedial actions are associated to the questions within each system survey forms and system I.D’s contained within Section 3 of this document.

6.1 SITE MANAGEMENT

6.1.1 Very High Priority

Very High risk, immediate action required

No Issues




6.1.2 High Priority

High Legionella risk, completion 0 – 3 months upon receipt of this document or by agreement

Action plan # Location Description Priority Allocated to Completed by Current status

MJ461426W0001 Site Management Water Systems Control

Observation

Some remedial actions given in the previous risk assessment have not been carried out. There are still.some incorrectly installed expansion vessels, Dead ends, dead legs, Scaled outlets, Low flow temperatures from some water heaters, no domestic supply flushing records to LPHW01, non Wras flexi hoses present, no expansion vessel flushing records.

Recommendation

Efforts should be made to ensure that all remedial actions recommended as part of the risk assessment are managed and closed out with appropriate action. Evidence of action taken should be recorded and made available for review.

Risk score: 16


Observation

It is considered that some of the named persons with responsibilities for water safety have not received appropriate training.

Risk score: 16





Recommendation

ACoP L8 (fourth edition) states that those specifically appointed to implement the control measures and strategies should be suitably trained to a level that ensures tasks are carried out in a safe, technically competent manner. All training records should be made available to view on any audit that is carried out. These training records should be regularly reviewed.


Observation

There was no evidence of a suitable staff training programme in place.

Recommendation

ACoP L8 (fourth edition) states that those specifically appointed to implement the control measures and strategies should be suitably trained to a level that ensures tasks are carried out in a safe, technically competent manner. All training records should be made available to view on any audit that is carried out. These training records should be regularly reviewed.

Risk score: 16


Observation

Risk score: 16





There are no suitable and sufficient water systems monitoring programme in place. There is no records of expansion vessel flushing, no descaling regime implemented, no inline filter and softener service records.

Recommendation

A suitable and sufficient monitoring programme for the prevention of legionnaires’ disease is a requirement in accordance with ACOP L8 (fourth edition). The written scheme contained within this document should be fully adopted.


Observation

No valid calibration certificates was available for thermometers used to carry out site water monitoring.

Recommendation

No valid calibration certificates was available for the thermometers used to carry out site water monitoring. The thermometers used to measure water temperatures, must be suitable and calibrated regularly against a primary referenced thermometer, certified against a national accreditation body on an annual basis.

Risk score: 16






Observation

Employees and representatives have not been consulted and informed about the potential of exposure to the legionella bacteria within the water systems.

Recommendation

All employees, or their representatives where appropriate, should be consulted and informed of the potential risks of exposure to Legionella from the site water systems.

Risk score: 16




6.1.3 Medium Priority

Medium Legionella Risk, completion 0 – 6 months upon receipt of this document or by agreement:



Observation

No records or not all monitoring records from the previous 5 years are available.

Recommendation

During the site survey; management records covering the previous five years were not seen / not made available/ only partially seen for the previous X years/months. This is a requirement under ACoP L8 (Fourth edition). This may be because of archiving; however, any previous records, along with all future records, should be made available for any possible audit that the site undergoes.

Risk score: 9

6.2 MAIN BUILDING

6.2.1 Very High Priority

Very High risk, immediate action required

No Issues




6.2.2 High Priority

High Legionella risk, completion 0 – 3 months upon receipt of this document or by agreement


MJ461426W0008

Main building

3rd Floor

Plant Room

Incoming cold water supply

Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

Risk score: 16





MJ461426W0014

Main building

3rd Floor

Plant Room


Observation

There are dead legs visibly present on this system. The dead leg is in the second floor Cleaners Cupboard 15mm x 6cm copper.

Recommendation

During the assessment, redundant lengths of pipework were identified as exceeding more than twice the size of the pipework diameter and are classed as dead-legs. Areas of pipework which are redundant are prone to stagnation. This is greatly emphasized within HSG274 (Part 2). These redundant lengths of pipework should be placed in the same manner as infrequently used outlets and flushed weekly as outlined within the written scheme. It is strongly recommended that, if these lengths of pipework are to remain out of use, they are removed from the system.

Risk score: 16

MJ461426W0015 Main building

3rd Floor

Plant Room


Observation

There are dead ends visibly present on this system. Photo 01 is in the

Risk score: 16





plant room and is 15mm copper by 3cm on 15mm source pipework. Photo 02 is outside cleaners, Photo 03 is a 15mm x 500mm dead end in waiting room on first floor by cleaners.

Recommendation

During the assessment, redundant lengths of pipework were identified as exceeding more than twice the size of the pipework diameter and classed as dead-ends. Areas of pipework which are redundant are prone to stagnation. This is greatly emphasized within HSG274 (Part 2). These redundant lengths of pipework should be removed from the system. However due to the location it was deemed not practical to remove this pipework, therefore these redundant lengths of pipework should be uncapped and placed in the same manner as infrequently used outlets and flushed weekly /twice weekly as outlined within the written scheme.

MJ461426W0016

Main building

3rd Floor

Plant Room


Observation

There are infrequently used outlets on this system. Photo 01 is second floor cleaners.

Risk score: 16





Recommendation

During the assessment, outlets/services were identified as infrequently used. Outlets/services which are infrequently used are prone to stagnation. This is greatly emphasised within HSG274 (Part 2). All infrequently used outlets as listed in section 4 of this document should be flushed weekly or as identified within the written scheme, included within this Risk Assessment. In addition , it is common that outlets come in and out of use. It is therefore important that a register is kept and updated as and when outlets come in and out of regular use. It is strongly recommended that, if these outlets are to remain out of use, they should be removed from the system ensuring no dead leg/end pipework remains.

MJ461426W0017

Main building

3rd Floor

Plant Room


Observation


Recommendation

Outlets throughout the site were seen to be scaled. Scale are known to support the proliferation of legionella bacteria. This is

Risk score: 16





emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

MJ461426W0020

Main building

3rd Floor

Plant Room

Cold water distribution system

Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses

Risk score: 16





that conform to the Water Regulations Advisory Scheme (WRAS) directory, ie crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

MJ461426W0021

Main building

3rd Floor

Plant Room


Observation

There are dead ends visibly present on this system. Photo 01 is behind courtroom 8 toilet 15mm x 6cm on 28mm source pipework. Photo 02 is in

area B library void, 28mm x 600mm on 28m source pipework, photo 01 is on same piece of pipework.

Recommendation

During the assessment, redundant lengths of pipework were identified as exceeding more than twice the size of the pipework diameter and classed as dead-ends. Areas of pipework which are redundant are prone to stagnation. This is greatly emphasized within HSG274 (Part 2). These redundant lengths of pipework should be removed from the system. However due to the location it was deemed not practical to remove this pipework, therefore these redundant lengths of

Risk score: 16





pipework should be uncapped and placed in the same manner as infrequently used outlets and flushed weekly /twice weekly as outlined within the written scheme.

MJ461426W0022

Main building

3rd Floor

Plant Room


Observation

There are infrequently used outlets on this system. Photo 01 2 x wash hand basins in first floor gents toilet.

Recommendation

During the assessment, outlets/services were identified as infrequently used. Outlets/services which are infrequently used are prone to stagnation. This is greatly emphasised within HSG274 (Part 2). All infrequently used outlets as listed in section 4 of this document should be flushed weekly or as identified within the written scheme, included within this Risk Assessment. In addition , it is common that outlets come in and out of use. It is therefore important that a register is kept and updated as and when outlets come in and out of regular use. It is strongly recommended that, if these outlets are to remain out of use, they should be removed from the system

Risk score: 16





ensuring no dead leg/end first floor remains.

MJ461426W0023

Main building

3rd Floor

Plant Room


Observation


Recommendation

Outlets throughout the site were seen to be scaled and/or seen to have debris present. Scale/debris are known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

Risk score: 16


2nd Floor

Cleaners

Low storage volume water heater

Observation

Some hot water temperatures recorded on this system were below 50°C . Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2). The

Risk score: 16





water heater is currently isolated and not used.

Recommendation

The system and current controls should be investigated and an action plan created to combat any faults identified. A regime of legionella sampling should be considered to identify if the system has been colonized. This sampling regime should be maintained until such time the system is proven to be under control.

MJ461426W0027

Main building

3rd Floor

Plant Room


Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is

Risk score: 16





emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

MJ461426W0028

Main building

Ground

Staff kitchen


Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors,

Risk score: 16





then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

MJ461426W0029

Main building

2nd Floor

Cleaners


Observation

This unit and outlets supplied by the heater are considered to be infrequently used.

Recommendation

During the assessment, outlets/services were identified as infrequently used. Outlets/services which are infrequently used are prone to stagnation. This is greatly emphasised within HSG274 (Part 2). All infrequently used outlets as listed in section 4 of this document should be flushed weekly or as identified within the written scheme, included within this Risk Assessment. In addition, it is common that outlets come in and out of use. It is therefore important that a register is kept and updated as and when outlets come in and out

Risk score: 16





of regular use. It is strongly recommended that, if these outlets are to remain out of use, they should be removed from the system ensuring no dead leg/end pipework remains.


Ground

Store Room


Observation


Recommendation

Outlets throughout the site were seen to be scaled. Scale are known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

Risk score: 16

MJ461426W0032

Main building

3rd Floor

Plant Room


Observation


Recommendation

Outlets throughout the site were seen to be scaled. Scale are known

Risk score: 16





to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

MJ461426W0033

Main building

2nd Floor

Cleaners


Observation


Recommendation


Risk score: 16


1st Floor

Cleaners


Observation


Risk score: 16





Recommendation


MJ461426W0034

Main building

Ground

Staff kitchen


Observation

Scale/debris was visible on tap outlets.

Recommendation

Outlets throughout the site were seen to be scaled and/or seen to have debris present. Scale/debris are known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

Risk score: 16





MJ461426W0038

Main building

2nd Floor

Gents Toilet

High storage volume water heater

Observation


Recommendation


Risk score: 16


2nd Floor


Risk score: 16





Gents Toilet

Observation

This unit and outlets supplied by the heater are considered to be infrequently used. Tap handles have been removed on two of the three mixer taps.

Recommendation

During the assessment, outlets/services were identified as infrequently used. Outlets/services which are infrequently used are prone to stagnation. This is greatly emphasised within HSG274 (Part 2). All infrequently used outlets as listed in section 4 of this document should be flushed weekly or as identified within the written scheme, included within this Risk Assessment. In addition, it is common that outlets come in and out of use. It is therefore important that a register is kept and updated as and when outlets come in and out of regular use. It is strongly recommended that, if these outlets are to remain out of use, they should be removed from the system ensuring no dead leg/end pipework remains.


1st Floor

Judges Chambers 1


Observation

Risk score: 16






Recommendation

Outlets throughout the site were seen to be scaled. Scale/debris are known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.

MJ461426W0041

Main building

2nd Floor

Gents Toilet


Observation


Recommendation


Risk score: 16

MJ461426W0044 Main building Combination water heater Risk score: 16





2nd Floor

Ladies Toilet

Observation


Recommendation


MJ461426W0046

Main building

1st Floor

Gents Toilet

Combination water heater

Observation

Inspection of the following tanks has shown that moderate internal contamination is evident. Contamination within the tanks is ideal to encourage microbial activity and legionella proliferation. This is

Risk score: 16





detailed within HSG274 (Part 2). To combat this issue, the tanks should undergo a full deep clean and disinfection.

Recommendation


MJ461426W0047

Main building

1st Floor

Courtroom 6 WC


Observation


Recommendation

Inspection of the following tanks has shown that moderate internal contamination is evident.

Risk score: 16





Contamination within the tanks is ideal to encourage microbial activity and legionella proliferation. This is detailed within HSG274 (Part 2). To combat this issue, the tanks should undergo a full deep clean and disinfection.

MJ461426W0045

Main building

1st Floor

Area B library


Observation


Recommendation


Risk score: 16





MJ461426W0051

Main building

1st Floor

Area B library


Observation

The CWST lid is not fixed and tight fitting. There is no lid fitted at all.

Recommendation

It is recommended that the tank lid is secured, or that the tank is fitted with new, vented, close fitting lid in line with BS8558:2015.

Risk score: 16

MJ461426W0048

Main building

1st Floor

Courtroom 6 WC


Observation

The CWST lid is not fixed and tight fitting. The lid is missing its locking screw.

Recommendation


Risk score: 16

MJ461426W0050

Main building

1st Floor

Gents Toilet


Observation


Risk score: 16





Recommendation


MJ461426W0049

Main building

3rd Floor

Plant Room


Observation

The CWST lid is not fixed and tight fitting. The tank has bowed with temperature change and the locking screw has not been inserted so there now is an open hole in the lid.

Recommendation


Risk score: 16

MJ461426W0053

Main building

2nd Floor

Ladies Toilet


Observation


Recommendation

It is recommended that the tank lid is secured, or that the tank is fitted with new, vented, close fitting lid in

Risk score: 16





line with BS8558:2015.

MJ461426W0052

Main building

1st Floor

Ladies Toilet


Observation

The CWST lid is not fixed and tight fitting. There is no lid attached to the unit.

Recommendation


Risk score: 16


2nd Floor

Judges Chambers WC


Observation

The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently 37.7

Recommendation

The system and current controls should be investigated, and an action plan created to combat any faults identified. This could include a

Risk score: 16





regime of legionella sampling to identify if the system has been colonized. This sampling regime should be maintained until such time the system is proven to be under control.


1st Floor

Courtroom 6 WC


Observation

The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently no heating to the unit.

Recommendation

The system and current controls should be investigated, and an action plan created to combat any faults identified. This could include a regime of legionella sampling to identify if the system has been colonized. This sampling regime should be maintained until such time the system is proven to be under control.

Risk score: 16

MJ461426W0057 Main building Combination water heater Risk score: 16





1st Floor

Area B library

Observation

The stored water in the unit is not maintained at a temperature of at least 55-60°C. Where stored temperatures fall below this temperature range, legionella bacteria are less likely to be killed within the vessel. This is emphasized within HSG274 (Part 2). Currently 13.1 Degrees.

Recommendation



1st Floor

Area B library


Observation

Some or all hot water temperatures recorded on this system were below 50°C. Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly

Risk score: 16





emphasized in HSG274 (Part 2).

Recommendation



1st Floor

Courtroom 6 WC


Observation

Some or all hot water temperatures recorded on this system were below 50°C (55°C in healthcare). Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2).

Recommendation

The system and current controls should be investigated, and an action plan created to combat any faults identified. This could include a regime of legionella sampling to identify if the system has been colonized. This sampling regime

Risk score: 16





should be maintained until such time the system is proven to be under control.


2nd Floor

Judges Chambers WC


Observation

Some or all hot water temperatures recorded on this system were below 50°C. Where temperatures are below this range, legionella bacteria become active, and are able to proliferate when the temperature drops below 45°C. This is greatly emphasized in HSG274 (Part 2).

Recommendation


Risk score: 16


1st Floor

Ladies Toilet


Observation


Risk score: 16





Recommendation


MJ461426W0068

Main building

2nd Floor

Ladies Toilet


Observation


Recommendation


Risk score: 16


3rd Floor


Risk score: 16





Plant Room

Observation


Recommendation

Outlets throughout the site were seen to be scaled. Scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to replace the outlet.


2nd Floor

Judges Chambers WC


Observation


Recommendation


Risk score: 16





MJ461426W0072

Main building

1st Floor

Courtroom 6 WC


Observation


Recommendation


Risk score: 16

MJ461426W0071

Main building

1st Floor

Gents Toilet


Observation


Recommendation

Outlets throughout the site were seen to be scaled. Scale are known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). Outlets detailed in section 4 of this document should be de-scaled, cleaned and disinfected. If de-scaling and cleaning is considered insufficient, it may be necessary to

Risk score: 16





replace the outlet.


1st Floor

Area B library


Observation


Recommendation


Risk score: 16


3rd Floor

Plant Room

Closed water system

Observation

The domestic cold water supplying the closed system is not regularly flushed. Due to the nature of the closed system, the water is only pulled through the pipework as and when required. This pipework, in effect, acts as a system dead-leg. Dead-legs are prone to stagnation.

Recommendation

Risk score: 16





Stagnation is a condition suitable for the proliferation of legionella bacteria. To combat this issue, the length of pipework should be flushed monthly as indicated within the written scheme, included within this Risk Assessment.


3rd Floor

Plant Room

Closed water system

Observation

The closed system fast fill connection was seen to be left connected to the domestic supply system on the heating pressurisation unit HPU01, If left connected; the connection presents a contamination risk should the system back-syphon, drawing in the water from the closed system to the main domestic supply.

Recommendation

The fast fill connection should be disconnected from the system when not in use, as emphasized within the Water Supply (Water Fittings) Regulations 1999 or Scottish Water Byelaws 2004. If this is not feasible, a more suitable backflow prevention device should be installed to the system in its place.

Risk score: 16




6.2.3 Medium Priority

Medium Legionella Risk, completion 0 – 6 months upon receipt of this document or by agreement:



3rd Floor

Plant Room


Observation

There is not an appropriate servicing and maintenance regime in place for inline filters.

Recommendation

Inline filters/scale inhibitors can act as a suitable location for the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). The filters/scale inhibitors should be inspected, cleaned, de-scaled and disinfected as defined within the written scheme included within this report. Where filters are integral to equipment i.e. Vending machines, evidence of the maintenance of the filters within these units should be included in the site water services Logbook.

Risk score: 9

MJ461426W0010

Main building

3rd Floor

Plant Room


Observation

All or some expansion/pressure vessels were found not to be installed correctly. Photo 01 is in staff kitchen.

Risk score: 9





Recommendation

Expansion/pressure vessels were identified to have been incorrectly installed and were seen to be mounted horizontally / inverted and or with no drain valve. Expansion vessels mounted in such a way / without suitable drain valves has an increased risk of stagnation and in addition they may accumulate debris from the water system. This is emphasized within HSG274 (Part 2). In order to combat the issue presented from stagnation, the expansion vessel should be re-mounted in a vertical position, ensuring the length of pipework is kept to a minimum and that an anti-legionella valve is installed. / a suitable drain valve is installed to enable regular flushing on a basis specified within the written scheme.


3rd Floor

Plant Room


Observation

Expansion/pressure vessels do not undergo routine inspection and/or no maintenance records were present.

Recommendation

There is no evidence that expansion/pressure vessels undergo

Risk score: 9





routine inspection and maintenance. HSG274 Part 2 states that expansion vessels should be flushed through and purged to drain regularly on a frequency as indicated within the written scheme within this document


3rd Floor

Plant Room


Observation

All or some expansion/pressure vessels are not approved against BS:6920.

Recommendation

There are several types of vessel available including diaphragm or bladder type, with fixed and interchangeable (replaceable) bladders. These internal bladders are often made of synthetic rubber such as EPDM and may support the growth of microorganisms including Legionella; these vessels should be checked and confirmed that these are approved against BS 6920.

Risk score: 9


3rd Floor

Plant Room


Observation

Additional drain valves are required to be fitted to all/some

Risk score: 9





expansion/pressure vessels. Photo 01 is in staff kitchen, Photo 02 is in store room.

Recommendation

Adequate drain valves are required in order to carry out regular flushing. In accordance with HSG274 Part 2, expansion vessels should be flushed through and purged to drain regularly on a frequency as indicated within the written scheme within this document

MJ461426W0018

Main building

3rd Floor

Plant Room


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be

Risk score: 9





necessary to replace the outlet.

MJ461426W0019

Main building

3rd Floor

Plant Room


Observation


Recommendation

Uninsulated pipework is subject to heat gain or heat loss from other heat sources including ambient temperature and or domestic hot water / heating pipework. In domestic hot water systems, insulation protects against heat loss. This is outlined within HSG274 (Part 2). All exposed areas of pipework should be fitted with the appropriate insulation.

Risk score: 9

MJ461426W0024

Main building

3rd Floor

Plant Room


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the

Risk score: 9





proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.

MJ461426W0025

Main building

3rd Floor

Plant Room


Observation


Recommendation

Uninsulated pipework is subject to heat gain or heat loss from other heat sources including ambient temperature and or domestic hot water / heating pipework. In domestic hot water systems, insulation protects against heat loss. This is outlined within HSG274 (Part 2). All exposed areas of pipework should be fitted with the appropriate insulation.

Risk score: 9

MJ461426W0035 Main building Low storage volume water heater Risk score: 9





Ground

Staff kitchen

Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.

MJ461426W0036

Main building

3rd Floor

Plant Room


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria.

Risk score: 9





This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.


Ground

Store Room


Observation


Recommendation


Risk score: 9





MJ461426W0042

Main building

2nd Floor

Gents Toilet


Observation


Recommendation


Risk score: 9

MJ461426W0043

Main building

1st Floor

Judges Chambers 1


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the

Risk score: 9





proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.


1st Floor

Ladies Toilet


Observation

A suitable lid vent is not present. It is necessary for the integral cold water storage tank to breathe as the water level rises and falls. This is detailed in the Water Supply (Water Fittings) Regulations 1999 or Scottish Water Byelaws 2004. There is no lid for a vent to be attached to.

Recommendation

A suitably screened lid vent should be installed to the tank/lid.

Risk score: 9


1st Floor

Courtroom 6 WC


Observation

A suitable lid vent is not present. It is necessary for the integral cold water

Risk score: 9





storage tank to breathe as the water level rises and falls. This is detailed in the Water Supply (Water Fittings) Regulations 1999 or Scottish Water Byelaws 2004. There is no lid vent present just a hole where one should be.

Recommendation


MJ461426W0055

Main building

1st Floor

Area B library


Observation

A suitable lid vent is not present. It is necessary for the integral cold water storage tank to breathe as the water level rises and falls. This is detailed in the Water Supply (Water Fittings) Regulations 1999 or Scottish Water Byelaws 2004. There is no lid to attach a vent to.

Recommendation


Risk score: 9


1st Floor

Ladies Toilet


Observation

Flexible hoses identified in the cold water system do not conform to the

Risk score: 9





water regulations advisory scheme (WRAS).

Recommendation


MJ461426W0063

Main building

2nd Floor

Ladies Toilet


Observation

Flexible hoses identified in the cold water system do not conform to the water regulations advisory scheme (WRAS).

Risk score: 9





Recommendation



3rd Floor

Plant Room


Observation


Recommendation

Flexible hoses were identified within

Risk score: 9





the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

MJ461426W0066

Main building

1st Floor

Gents Toilet


Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water

Risk score: 9





Regulations Advisory Scheme (WRAS) directory. These hoses are known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.

MJ461426W0065

Main building

1st Floor

Area B library


Observation


Recommendation

Flexible hoses were identified within the systems that do not or could not be proven to conform to the Water Regulations Advisory Scheme (WRAS) directory. These hoses are

Risk score: 9





known to contain materials, more specifically ethylene propylene diene monomer (EPDM). Evidence has shown these hoses can act as a suitable breeding ground for bacteria including Legionella. This is emphasized within HSG274 (part 2). If the hoses meet the above factors, then they should either be removed and piped through with rigid copper pipework, or replaced with hoses that conform to the Water Regulations Advisory Scheme (WRAS) directory, i.e. Crossed linked polyethylene hoses. The locations of such hoses are listed within section 4 of this document.


1st Floor

Area B library


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in section 4 of this document should be

Risk score: 9





cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.

MJ461426W0078

Main building

1st Floor

Gents Toilet


Observation


Recommendation


Risk score: 9


1st Floor

Courtroom 6 WC


Observation

Risk score: 9






Recommendation



2nd Floor

Judges Chambers WC


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with spray/other inserts detailed in

Risk score: 9





section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.

MJ461426W0075

Main building

3rd Floor

Plant Room


Observation


Recommendation


Risk score: 9


2nd Floor


Risk score: 9





Ladies Toilet

Observation


Recommendation



1st Floor

Ladies Toilet


Observation


Recommendation

Spray/other inserts are known to be prone to harbouring scale/debris. This increased amount of debris/scale is known to support the proliferation of legionella bacteria. This is emphasized within HSG274 (Part 2). All outlets fitted with

Risk score: 9





spray/other inserts detailed in section 4 of this document should be cleaned, de-scaled and disinfected on a frequency outlined within the written scheme, regardless of condition. If de-scaling and cleaning is considered insufficient it may be necessary to replace the outlet.




7 ASSESSOR NOTES

From the information gained during the assessment, the risk assessor concluded that the site had areas of

although not a legislative requirement, rather an action/item improvement that will further reduce the risk of

either proliferation or dissemination of the legionella bacteria.

These observations may also include items that, although outside of legionella management, would fall under The Health and Safety at Work Act 1974 regulations. Other observations can also be issues that the risk assessor felt should be bought to the attention of the

relevant responsible person.

7.1 MAIN BUILDING

7.1.1 Assessor comments

Courtroom 8.Note: The hot water is struggling to get to the tap outlet from CWH06. This could

possibly be an air lock in the system and should be investigated.

LSWH02.Note: LSWH02 in third floor cleaners has been isolated off, this may be due to an expansion

vessel being removed and an open dead leg being created.

Gents Toilet 1st Floor.Note: There are two mixer taps which have no tap handles on currently, these

should be fixed with immediate effect as they are infrequently used.

Medical Room.Note: The medical room still has a mixer tap on a wash hand basin, but it is no longer

connected to a water system.

Cleaners Room.Note: The cleaners room on the ground floor no longer has a low volume storage

water heater connected to a supply.




8 WRITTEN SCHEME OF CONTROL AND PREVENTION

The Health and Safety Executive requires all water systems, identified as operating in such a way that the risk

of Legionellosis is evident, be managed to minimise or eliminate that risk, as far as reasonably practicable. This

is achieved by the formation of a written scheme of prevention or corrective actions requiring

implementation. This written scheme is inclusive in all management and maintenance programmes

commissioned for the control of risk of Legionellosis. Primary objectives include: -

- identifying and ensuring proper application of maintenance, repair, cleaning and treatment

regimens for all water services and ancillary equipment in order to maintain satisfactory

water quality with respect to potential Legionella contamination

- ensuring that sufficient information, instruction, training and supervision is provided for, or

undertaken by, those persons involved in site water services, defining clear responsibilities

and providing formal communication lines for reporting unacceptable situations and

resolving problems

- establishing written standards and performance criteria for water services, keeping clear

records of all activities carried out and results obtained in meeting agreed objectives, and

auditing compliance regularly.

Documentation

The Health and Safety Executive Approved Code of Practice requires that a log book is maintained on site with

up to date details on the following: -

- Nominated responsible persons with clearly defined lines of communication and details of subcontractors and their relative positions.

- the Risk Assessment

- a written scheme of control and minimising risk

- schematic drawings of those systems identified as at risk

- records of all actions taken, signed by the operator.

These records must be kept for a minimum of five years and be available for inspection by the HSE or the Local

Environmental Health Officer upon request.

The following listing is intended as a general guide to the type and frequency of routine maintenance tasks for

the site water services identified in the Risk Assessment. Included, are the minimum requirements for an

adequate prevention and control programme.

From each task, a clear instruction should be provided by the organisation responsible for that task, including

detailed safety precautions and reporting procedures. All tasks undertaken must be recorded, and each entry

signed and dated by the responsible person.

Records must be retained for a minimum of five years and be available on site for inspection.

Where appropriate, all working practices and procedures should comply with the relevant British or industry

standard.

All water treatment conditioning chemicals used on these tasks must be environmentally acceptable and

supplied by the same specialist supplier. Provision must be made for the safe storage, handling and proper

disposal of all chemicals. A safety data sheet provided by the chemical supplier must be available. A COSHH

assessment must be carried out, addressing the chemical itself and its specific application on site.




The following generic schemes of control will include tasks required for the systems identified on site during this survey.

8.1 WATER SYSTEMS LEGIONELLA CONTROL MANAGEMENT

Task Frequency

In accordance with ACoP L8 (Fourth edition 2013), a risk assessment must be carried out and reviewed regularly or whenever there is reason to believe that the current assessment is no longer valid.

To be determined by the Duty holder

The schematic diagram of the water system must be regularly assessed for its validity. This should be performed, as a minimum, on an annual basis, or more frequently if building conditions or inspection results indicate water system changes.

Annually or as required

Perform regular review meetings to discuss the preventative regime and any outstanding remedial actions. This should be performed, as a minimum, on an annual basis, or more frequently if building conditions or inspection results require.

Minimum annual Basis

Review the operation and performance of the written scheme of control and prevention to comply with the requirements under L8 (Fourth edition 2013). This should be performed, as a minimum, on an annual basis, or more frequently if required by building conditions or inspection results require.


Review the management structure to ensure this correctly represents the actual structure. This should be performed, as a minimum, on an annual basis, or more frequently if changes in personnel occur.


Review the legionella awareness and competence of those involved with the management process. This should be performed, as a minimum, on an annual basis, or more frequently if changes in personnel occur.


Review the non-conformance process, including the detection of legionella within a water system plan, ensuring this represents actual performance. This should be performed, as a minimum, on an annual basis, or more frequently if changes in the regime management, personnel or building water system use occur.


Review the results and inspection results to ensure the operating parameters of the system are being achieved. This should be performed, as a minimum, on an annual basis, or more frequently if changes in the regime management, personnel or building water system use occur.


Any temperature thermometers should undergo regular calibration to ensure the unit is in correct working order.

Annually or as per manufacturers’

instructions

8.2 INCOMING COLD WATER SUPPLY

Task Frequency

Flush to waste advised high risk water services within infrequently used areas. Flush the outlets until the temperature at the outlet stabilises and is comparable to supply water and purge to drain Regularly use the outlets to minimise the risk from microbial growth in the peripheral parts of the water system, sustain and log this procedure once started. Infrequently used equipment within a water system (ie not used for a period equal to or greater than seven days) should be included on the flushing regime. For high risk populations, eg healthcare and care homes, more frequent flushing may be required as indicated by the risk assessment

Weekly or more frequent if a high risk population premise

Chlorine dioxide systems require routine inspection and maintenance as follows;

Weekly – check the system operation and chemical stocks in the reservoir;

Monthly – test the treated water for both chlorine dioxide and total oxidant/ chlorite at an outlet close to the point of injection to verify the dosage rate and conversion yield;

Monthly – measure the concentration of chlorine dioxide at the sentinel taps – the

Weekly,

Monthly,

Annually




concentration should be at 0.1-0.5 mg/l; chlorine dioxide and total oxidant and adjust the chlorine dioxide dosage to establish the required residual at the sentinel sample points;

Annually – test the chlorine dioxide and total oxidant/chlorite concentration at a representative selection of outlets throughout the distribution system – the concentration should be at 0.1-0.5 mg/l; chlorine dioxide and total oxidant.

Check temperatures at sentinel taps (typically those nearest to and furthest from the incoming cold supply to the building, but may also include other key locations on long branches to zones or floor levels). These outlets should be below 20 °C within two minutes of running the cold tap. To identify any local heat gain, which might not be apparent after one minute, observe the thermometer reading during flushing

Monthly

The expansion vessel should be flushed to reduce the potential of stagnant water accumulating within it.

Monthly

Taps with spray /other inserts should be removed, cleaned, de-scaled and disinfected. Quarterly or more

frequent if necessary

Strainers installed to a water system can act as bacterial breeding grounds. The operation

and maintenance of strainers should be removed and cleaned periodically to remove any

dirt, debris or nutrients they may provide for bacteria such as legionella.

Annually

RPZ valves installed to the system should be serviced, tested and maintained regularly. Annually

Check thermal insulation is intact. Annually

All representative outlets should be tested over a twelve-month period, to ensure the temperature is below 20˚C after running for up to two minutes.

Representative selection of outlets on a

rotational basis

The operation and maintenance of the inline filters including inline scale inhibitors should be followed as in accordance to the manufacturers’ guidelines.

As required, as per manufacturers’

instructions

Borehole/spring water supply should be monitored to ensure that suitable potable or domestic use, that the quality is maintained. If pre-treatment equipment or injections of chemical disinfectants are used, then this equipment needs to be properly maintained.

As per private water regulations guidance

8.3 COLD WATER STORAGE TANKS

Task Frequency

Check the tank water temperature remote from the ball valve and the incoming mains temperature. Parameters, below 20°C. Record the maximum temperatures of the stored and supply water recorded by fixed maximum/minimum thermometers where fitted

Annually (Summer) or as indicated by the

temperature profiling

Inspect and report the condition of all cold water storage tanks, including Water Regulation compliance, structural integrity and report upon any contaminations. Record findings and date of activity.

Annually

8.4 COLD WATER DISTRIBUTION SYSTEMS

Task Frequency



If the system has more than one booster pump, these pumps should be alternated to prevent any stagnation build up. Where these pumps are automatically alternated check the operation of the pumps.

Weekly




Chlorine dioxide systems require routine inspection and maintenance as follows;

Weekly – check the system operation and chemical stocks in the reservoir;

Monthly – test the treated water for both chlorine dioxide and total oxidant/ chlorite at an outlet close to the point of injection to verify the dosage rate and conversion yield;

Monthly – measure the concentration of chlorine dioxide at the sentinel taps – the concentration should be at least 0.1 mg/l; and adjust the chlorine dioxide dosage to establish the required residual at the sentinel sample points;

Annually – test the chlorine dioxide and total oxidant/chlorite concentration at a representative selection of outlets throughout the distribution system – the concentration should be at least 0.1 mg/l chlorine dioxide.

Weekly,

Monthly,

Annually

Check temperatures at sentinel taps (typically those nearest to and furthest from the cold water storage tank, but may also include other key locations on long branches to zones or floor levels). These outlets should be below 20 °C within two minutes of running the cold tap. To identify any local heat gain, which might not be apparent after one minute, observe the thermometer reading during flushing

Monthly

The expansion vessel should be flushed to reduce the potential of stagnant water accumulating within it.

Monthly



Check thermal insulation is intact. Annually

Strainers installed to a water system can act as bacterial breeding grounds. The operation and maintenance of strainers should be removed and cleaned periodically to remove any dirt, debris or nutrients they may provide for bacteria such as legionella.

Annually

RPZ valves installed to the system should be serviced, tested and maintained regularly. Annually

All representative outlets should be tested over a twelve-month period, to ensure the temperature is below 20˚C after running for up to two minutes.

Representative selection of outlets on a

rotational basis



instructions

8.5 LOW STORAGE VOLUME WATER HEATERS AND SYSTEM

Task Frequency



Check and record water temperatures to confirm the heater operates at least 50°C (55°C within healthcare premises) at a representative (sentinel) outlet (including TMV input if present)

Monthly






Annually

Risk assess whether the TMV fitting is required, and if not, remove Where needed, inspect, clean, descale and disinfect any strainers or filters associated with TMVs To maintain protection against scald risk, TMVs require regular routine maintenance carried

Annually




out by competent persons in accordance with the manufacturer’s instructions.



instructions

8.6 HIGH STORAGE VOLUME WATER HEATERS AND SYSTEM

Task Frequency



Check and record water temperatures to confirm the heater operates at 60 °C. Monthly

Check and record water temperature at a representative (sentinel) outlet to ensure the temperature is at least 50°C (55°C within healthcare premises) within one minute of running the outlet.

Monthly






Annually

Risk assess whether the TMV fitting is required, and if not, remove Where needed, inspect, clean, descale and disinfect any strainers or filters associated with TMVs To maintain protection against scald risk, TMVs require regular routine maintenance

carried out by competent persons in accordance with the manufacturer’s instructions.

Annually



instructions

8.7 COMBINATION WATER HEATERS AND SYSTEM

Task Frequency



Check and record water temperatures to confirm the heater operates at 60 °C. Monthly

Check and record water temperature at a representative (sentinel) outlet to ensure the temperature is at least 50°C (55°C within healthcare premises) within one minute of running the outlet.

Monthly



Check, inspect and record water temperatures at the CWST inlet and from the stored water, away from inlet location, to ensure they are below 20˚C.

Annually




Inspect the integral cold water header tanks as part of the cold water storage tank inspection regime, clean and disinfect as necessary. If evidence shows that the unit regularly overflows hot water into the integral cold water header tank, instigate a temperature monitoring regime to determine the frequency and take precautionary measures as determined by the findings of this monitoring regime

Annually




Annually

Risk assess whether the TMV fitting is required, and if not, remove Where needed, inspect, clean, descale and disinfect any strainers or filters associated with TMVs To maintain protection against scald risk, TMVs require regular routine maintenance carried

out by competent persons in accordance with the manufacturer’s instructions.

Annually



instructions

8.8 CLOSED WATER SYSTEMS

Task Frequency

Domestic pipework supplying closed water systems with feed and expansion tanks /pressurisation units/fast fill connection loops should be classed as infrequently used and the supply pipework to each feed and expansion/pressurisation unit/fast fill connection loop should be opened up and flushed for several minutes to ensure no stagnant water can remain within this supply pipework also ensuring adequate backflow protection is in place. Additional Note: Although closed systems in normal use are low risk, whilst carrying out ppm or maintenance tasks, appropriate ppe and rpe or hazard assessment is carried out.

Monthly




9 ASSET REGISTER

Equipment Location Asset number

Drinking water chiller Main building-2nd Floor-Waiting Area

CH-1

Drinking water chiller Main building-1st Floor-Waiting Area CH-2

Drinking water chiller Main building-Ground-Staff kitchen CH-3

Cold tap Main building-2nd Floor-Cleaners CT-1-2

Cold tap Main building-1st Floor-Cleaners CT-3-4

Cold tap Main building-Ground-Cleaners CT-5

Cold water distribution system Main building-3rd Floor-Plant Room CWDS01

Combination water heater Main building-3rd Floor-Plant Room CWH01

Combination water heater Main building-2nd Floor-Ladies Toilet CWH02

Combination water heater Main building-2nd Floor-Judges Chambers WC

CWH03

Combination water heater Main building-1st Floor-Ladies Toilet CWH04

Combination water heater Main building-1st Floor-Gents Toilet CWH05

Combination water heater Main building-1st Floor-Area B library

CWH06

Combination water heater Main building-1st Floor-Courtroom 6 WC

CWH07

Cold water storage tank Main building-3rd Floor-Plant Room CWST01

Dishwasher Main building-Ground-Staff kitchen DW-1

Expansion vessel Main building-Ground-Staff kitchen EV01

Expansion vessel Main building-1st Floor-Cleaners EV02

Expansion vessel Main building-3rd Floor-Plant Room EV03

Heating pressurisation unit Main building-3rd Floor-Plant Room HPU01


Main building-2nd Floor-Gents Toilet HSWH01


Main building-1st Floor-Judges Chambers 1

HSWH02

Hot tap Main building-2nd Floor-Cleaners HT-1

Hot tap Main building-1st Floor-Cleaners HT-2

Hot water boiler Main building-Ground-Staff kitchen HWB-1

Inline filter Main building-2nd Floor-Waiting Area

IF-1

Inline filter Main building-1st Floor-Waiting Area IF-2

Inline filter Main building-Ground-Staff kitchen IF-3

Closed water system Main building-3rd Floor-Plant Room LPHW01

Low storage volume water heater Main building-3rd Floor-Plant Room LSWH01




Low storage volume water heater Main building-2nd Floor-Cleaners LSWH02

Low storage volume water heater Main building-1st Floor-Cleaners LSWH03

Low storage volume water heater Main building-Ground-Staff kitchen LSWH04

Low storage volume water heater Main building-Ground-Store Room LSWH05

Incoming cold water supply Main building-3rd Floor-Plant Room MCW01

Mixer tap Main building-2nd Floor-Judges Chambers WC

MT-1

Mixer tap Main building-2nd Floor-WC MT-10

Mixer tap Main building-2nd Floor-Kitchen MT-11

Mixer tap Main building-1st Floor-Ladies Toilet MT-12-14

Mixer tap Main building-1st Floor-Gents Toilet MT-15-17

Mixer tap Main building-1st Floor-Judges Chambers 1

MT-18

Mixer tap Main building-1st Floor-Court 8 WC MT-19

Mixer tap Main building-1st Floor-Courtroom 6 WC

MT-20

Mixer tap Main building-1st Floor-Court room 5 WC

MT-21

Mixer tap Main building-1st Floor-Courtroom WC 7

MT-22

Mixer tap Main building-Ground-Gents Toilet MT-23-26

Mixer tap Main building-2nd Floor-Ladies Toilet MT-2-5

Mixer tap Main building-Ground-Ladies Toilet MT-27-30

Mixer tap Main building-Ground-Staff kitchen MT-31

Mixer tap Main building-Ground-Bailiffs Kitchen

MT-32

Mixer tap Main building-Ground-Medical Room MT-33

Mixer tap Main building-2nd Floor-Gents Toilet MT-6-9

WC Main building-2nd Floor-Judges Chambers WC

WC-1

WC Main building-1st Floor-Gents Toilet WC-12-14

WC Main building-1st Floor-Judges Chambers 1

WC-15

WC Main building-1st Floor-Court 8 WC WC-16

WC Main building-1st Floor-Courtroom 6 WC

WC-17

WC Main building-1st Floor-Court room 5 WC

WC-18

WC Main building-1st Floor-Courtroom WC 7

WC-19

WC Main building-Ground-Gents Toilet WC-20-23

WC Main building-2nd Floor-Ladies Toilet WC-2-4




WC Main building-Ground-Ladies Toilet WC-24-26

WC Main building-2nd Floor-Gents Toilet WC-5-7

WC Main building-2nd Floor-WC WC-8

WC Main building-1st Floor-Ladies Toilet WC-9-11

Water softener Main building-Ground-Staff kitchen WS01




10 DOMESTIC WATER SYSTEM SCHEMATICS

Client: Ministry Of Justice Water Address: MOJ - BARNET COUNTY COURT [WTR] REGENTS PARK ROAD N31BQ

Date Assessed: 12 March 2019 Drawing No:

Site: MOJ - BARNET COUNTY COURT [WTR] Assessor Name:

Adam Midson 1 of 1

We cannot guarantee that all pipework passing underground or through floors, walls and ceilings has been traced, and it is possible that certain system dead-ends or dead legs may not have been identified as this was not an intrusive survey. As a result the schematic diagram(s) contained within this report only details the visible or assumed pipework. Whilst every effort has been made to ensure the accuracy of the content of this document, Mitie Water will accept no responsibility for any omissions.




10.1 SCHEMATIC KEY

Hot Water Supply

Mains Cold Water

Tanked Cold Water

Chemical Dosing Line

Room/Floor Border

Incoming Supply

Cold Water Storage Tank

Hot Water Storage Vessel

Combination Water Heater

High Storage Water Heater

Low Storage Water Heater

Incoming Mains Stop Valve

RPZ

Single non-return (check) Valve

Isolation Valve

Isolation Valve (closed)

Double non-return (check) Valve

Reduced Pressure Zone Valve (RPZ)

Solenoid ValveS

Pressure Reducing Valve

Pump

Plate Heat Exchanger

Thermostatic Mixing Valve (TMV)

Thermostatic Shower

Mixer Shower

Electric Shower

Strainer

Fire Hose Reel

Inline Filter

Ultra Violet Lamp

Expansion Vessel

Combi Boiler

CWST

Temperature Gauge

C

V

DW

WM

Hydro Tap

Drinking Water Chiller Unit

Vending Machine

Dishwasher

Washing Machine

SL Sluice Cistern

Water Softener

Emergency Eye Wash

Emergency Shower withIntegral Header Tank

Cold Only Shower

Bore Hole Cold Water

Grey/Recycled Water

WDU Waste Disposal Unit

Mains coldNearest sentinel point

PP Potato Peeler

Dead-leg

Feed and Expansion TankFET

Dead-end

Soft Water

Instantaneous Water Heater

SLM Sluice Machine

Thermostatic Mixer Tap (TMVT)

CM Coffee Maker

HWB Hot Water Boiler

HPU

CHPU

HeatingPressurisation unit

Chilled WaterPressurisation Unit

M

P

Water Meter

Pressure Gauge

HWSV

CWH

CB

HSWH

LSWH

IWH

PHE

Emergency Shower

T

ICE Ice Making Machine

NS

FS

MPS

NS

FS

FS

MPS

NS

MPS

Mains coldMultipoint sentinel

Tanked coldNearest sentinel point

Tanked coldFurthest sentinel point

Tanked coldMultipoint sentinel

Hot waterNearest sentinel point

Hot waterFurthest sentinel point

Hot waterMultipoint sentinel

ToiletWC

UR Urinal

Wash hand basinWhb

Mains cold furthest Sentinel point

NSBorehole Nearest sentinel point

FS Borehole Furthest sentinel point

MPSBorehole Multipoint sentinel

SteamerSTM

H Humidifier

CSO Combi Steam Oven




11 APPENDIX:

11.1 CODE OF CONDUCT




11.2 ASSESSOR EXPERIENCE AND QUALIFICATION

Assessor Experience and Qualification

Name: Adam Midson

Title Legionella Risk Assessor

Qualifications:

To compliment Adam in carrying out his duties, he has certification in the following courses/training:

Health & Safety Certificate

Energy efficiency evaluation

CSCS site competency card

QHSE Asbestos awareness

Part L energy efficiency

React fast plumbing certificate

BPEC Water regulations

Logic heating & hot water design and specification

Legionnaire awareness training acop l8

CSCS site competency card

BPEC water treatment risk assessor course.

First aid accredited

EUSR Blue Card

Extensive Mitie Training

Confined spaces course

Legionella module 3

WS8- Legionella Risk assessment of hot and cold water systems

WS14 Water Supply (Water Fittings) Regulations Course

IOSH Core safety Passport City and Guilds Water Regulations Course

Experience:

Extensive experience specific to Legionella Risk Assessments:

4 years’ experience of carrying out Legionella risk assessments on commercial and domestic hot and cold water systems, Adam has looked after customers in many sectors including, doctors and dental practices, young offender’s units, schools, offices, banks, and military bases. As well as care homes and facilities for patients with mental illnesses. Adam has carried out many key legionella combative tasks including tank cold water storage tank cleans, mains water injections, shower and tap cleans/descales.

Additional experience in:

Adam has extensive experience in plumbing and drainage to homes and premises alike, which holds him in good stead when carrying out water risk assessment as it has raised his awareness of water regulations and how water assets should be operating.




11.3 GLOSSARY OF TERMS

Aerosol A suspension in a gaseous medium of solid particles, liquid particles or solid and liquid

particles having negligible falling velocity.

Algae A small, usually aquatic, plant which requires light to grow, often found on exposed areas

of cooling towers.

Air-conditioning A form of air treatment whereby temperature humidity and air cleanliness are all

controlled within limits determined by the requirements of the air-conditioned enclosure.

Antibodies Substances in the blood which destroy or neutralise various toxins or components of

bacteria known generally as antigens. The antibodies are formed as a result of the

introduction into the body of the antigen to which that are antagonistic as in all infectious

diseases.

Bacteria (Singular bacterium) a microscopic, unicellular (or more rarely multicellular) organism.

Biocide A substance which kills micro-organisms.

Biofilm A community of bacteria and other micro-organisms, embedded in a protective layer with

entrained debris, attached to a surface.

Calorifier An apparatus used for the transfer of heat to water in a vessel by indirect means, the

source of heat being contained within a pipe or coil immersed in the water.

Chlorine An element used in disinfection.

Cold water service (CWS) Installation of plant pipes and fitting in which cold water is stored, distributed and

subsequently discharged.

Dead end/blind end A length of pipe closed at one end through which no water passes.

Dead leg Pipes leading to a fitting through which water only passes when there is draw-off from the

fitting.

Dip slide (s) A dip slide is a means of testing the microbial content of liquids. It consists of a plastic

carrier bearing a sterile culture medium which can be dipped in the liquid to be sampled.

It is then incubated to allow microbial growth. The resulting microbial colonies are

estimated by reference to a chart.

Disinfection A process which destroys or irreversibly inactivates micro-organisms and reduces their

number to a non-hazardous level.

Distribution circuit Pipework which distributes water from a hot or cold water plant to one or more

fittings/appliances.

Domestic water services

(DWS)

Hot and cold water intended for personal hygiene, culinary, drinking water or other

domestic purposes.




Glossary of Terms (continued)

Fouling Organic growth or other deposits on heat transfer surfaces causing loss in efficiency.

Hot water service (HWS) Installation of plant, pipes and fittings in which water is heated, distributed and

subsequently discharged (not including cold water feed tank or cistern).

Legionnaires’ disease A form of pneumonia caused by legionella bacteria.

Legionellae The genus legionella belongs to the family legionellaceae which has over 40 species.

These are ubiquitous in the environment and found in a wide spectrum of natural and

artificial collections of water.

Legionella Type of aerobic bacterium which is found predominantly in warm water environments.

(singular of legionellae)

L. Pneumophila One of the causative organisms of Legionnaires’ disease.

Legionellosis Any illness caused by exposure to legionella.

Pontiac fever A disease caused by species of legionella, an upper respiratory illness less severe than

Legionnaires’ disease.

Micro-organism An organism of microscopic size including bacteria, fungi and viruses.

Nutrient A food source for micro-organisms.

Pasteurisation Heat treatment to destroy micro-organism usually at high temperature.

Planktonic Free floating micro-organisms in an aquatic system.

ppm Parts per million: a measure of dissolved substances given as the number of parts there

are in a million parts of solvent. It is numerically equivalent to milligrams per litre (ml/l)

with respect to water.

Retention time Time a chemical is retained in the system.

Scale inhibitors Chemicals used to control scale. They function by holding up the precipitation process

and/or distorting the crystal shape, thus preventing the build-up of a hard adherent scale.

Sero-group A sub-group of the main species.

Sentinel taps For a hot water services – the first and last taps on a recirculating system. For cold water

systems (or non-recirculating hot water system), the nearest and furthest taps from the

storage tank. The choice of sentinel taps may also include other taps which are considered

to represent a particular risk.

Sessile Aquatic micro-organisms adhering to a surface normally as part of a biofilm.




Glossary of Terms (continued)

Sludge A general term for the soft mud-like deposits found on heat transfer surfaces or other

important sections of a cooling system. Also found at the base of Calorifiers and cold

water storage tanks.

Shunt pump A circulation pump fitted to hot water service/plant to overcome the temperature

stratification of the stored water.

Slime Mucus-like exudates which covers a surface produced by some micro-organisms.

Stagnation The condition where water ceases to flow and is therefore liable to microbiological

growth.

Strainers A course filter usually positioned upstream of a sensitive component such as a pump

control valve or heat exchanger to protect it from debris.

Thermal disinfection Heat treatment to disinfect a system.

Thermostatic mixing valve Mixing valve which the temperature at the outlet is pre-selected and controlled

automatically by the valve.

Total viable counts (TVC) The total number of cultural bacteria (per volume or area) in a given samples (does not

include legionella).

Risk assessment Identifying and assessing the risk from Legionellosis from work activities and water

sources on premises and determining any necessary precautionary measures.

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