IHEA HFMC Stuart Lloyd. Managing Legionella: Achieving Best Practice. Legionella background

Transcription

1 Stuart Lloyd worked in the industry since 1986 worked for 7 years with the water treatment arm of a Maintenance Contractor undertaking Legionella Risk Assessments including costing of any associated remedial works required Senior Public Health Engineer (Plumbing designer) in the UK equivalent to a Senior Hydraulics Designer in Australia moved to Australia 2009 Managing Legionella: Achieving Best Practice STUART LLOYD SENIOR HYDRAULIC DESIGNER Legionella background Legionella activity vs temperature and increased risk Conditions required for the multiplication of Legionella are: Water Nutrients Legionella can hide out in scale, rust, sludge and debris Legionella breed within the protozoa Temperatures within the breeding range for legionella Reproduced courtesy of NSW Department of Health 1

2 Sets a higher benchmark for LP management and risk reduction in Australia. Published November 2013 Covers both hot AND cold water services Water Quality Risk Management Plan (WQRMP) Hazard Analysis Critical Control point (HACCP) Centre for Healthcare Related Infection Surveillance and Prevention (CHRISP) Health and Safety Executive HSE L8 Legionnaires' disease Published January 2014 The Control of legionella bacteria in water systems Approved Code of Practice and guidance 2

3 UK Legislation and Guides Timeline Health and Safety Executive HSE L8 Legionnaires' disease Health and Safety Executive (HSE) guidance note EH48 1 st documented Legionella Outbreak, Philadelphia The Health and Safety at Work etc. Act 1974 Health and Safety Executive HS(G)70 Health Technical Memorandum 2040/2027 HSE L8 Currently undergoing a HSE L8 review and out for Public Consultation Control of Substances Hazardous to Health (COSHH) ACOP Guidance The Control of legionella bacteria in water systems Approved Code of Practice and guidance Approved code of practice legislative Guidance - nonlegislative UK Legionella related guidance and literature There exists a multitude of literature and guidance material, the most relevant for our purposes are: Department of Health: HTM 04-01: The control of Legionella hygiene, safe hot water, cold water and drinking water systems (supersedes and combines HTM 2040 & 2027) Building Services Research and Information Association (BSRIA) AG19/2000: Guide to legionellosis Operation and Maintenance AG20/2000: Guide to legionellosis Risk Assessment AG21/2000: legionellosis Control Log Book HSE L8 Management responsibilities, training and competence Maintenance Personnel Training Understanding of implications Personal Qualities Statutory Duty Holder Board member Self employed person Landlord Access to a competent help Appoint a Responsible Person Responsible Person Manager, Director or similar status with sufficient authority Competence and knowledge of installations and implications Ensure tests check etc undertaken in timely and effective manner Maintain records test, results, training etc Check the competency of staff, specialists and consultants Water Treatment Specialist Training Equipment Up to date knowledge Consultant Best practice design Understand the risks for hot AND cold water systems HSE L8 - Risk Assessments HSE L8 Record keeping Review the risk assessment regularly (at least every two years) and if there is a reason to suspect that it is no longer valid: modifications to the water system changes to the use of the building availability of new information on methods of control existing measures no longer effective a case of Legionnaires disease/legionellosis Management and communication procedures regularly reviewed Responsible person to retain records Records kept for the period they remain current and for at least two years after Records of monitoring, inspection, testings or checks should be kept for at least five years Consider a separate water services log book for all water system. (Water Management Society) 3

4 HSE L8 Hot and cold water services Designed to prevent or minimise conditions for legionella growth and allow easy cleaning and disinfection. In particular: materials - avoid organic materials low corrosion materials water storage tanks fitted with close fitting covers and insect screens multiple linked tanks designed and installed to prevent stagnation accumulator vessels hot water generation with little or no storage showers should not be fitted where little or no use thermostatic mixing valves (TMV s) pipework as short as possible TMVs not be used with spray taps HSE L8 Hot and cold water services remove infrequently used hot and cold water taps, showers etc where infrequently used taps and showers are retained flush on a weekly basis disinfection of all hot and cold water services AS3500 pipes 80 mm and larger (non tanked supplies) require disinfection HSE L8 Hot water services HSE L8 Cold water services cylinders not to be oversized increased risk of stagnation and higher energy costs multiple hot water storage cylinders to be installed in parallel in a balanced arrangement circulating systems to be designed to ensure temperatures within the risk range are avoided (>55ºC) HW temperatures should achieve at least 50ºC (or the thermostatic mixing valve set point) within 1 minute no time within Australian Standards but 10m (6m NSW) total is stipulated provide timed shunt pumps to circulate the contents of large calorifiers to prevent temperature stratification within. HW pipework to be insulated Avoid excessive dead legs or trace heat pipework where necessary. minimise the volume of cold water stored cold water storage tanks in a cool place and insulated cold water piping should be insulated and positioned away from heat sources HSE L8 Hot and cold water services HSE L8 Other risk systems Maintenance tasks Frequency Hot Water Cold Water Comments Weekly Flushing of infrequently used Flushing of infrequently Record/log flushing outlets used outlets Flush emergency drench Already required under AS 4775 showers/eyewash Monthly Temperature monitoring Temperature monitoring Incoming mains water supply, Tanks and water heaters HW flow and returns and representative No of outlets. Legionella sampling of warm Warm water systems to be used in conjunction with water systems alternative mean s of legionella prevention. Once the efficiency has been proven the frequency may be reduced Quarterly Shower heads and tap Shower heads and tap Remove, clean and disinfect shower heads and spreaders spreaders hoses and tap spreaders Six monthly Inspect cold water storage For signs of sedimentation and slime in tanks or tanks internally surface scum Annually Drain, clean and inspect HW Inspect cold water storage If necessary drain, clean and disinfect CW storage cylinders internally tanks internally tanks Ultrasonic humidifiers/water misting systems Spray humidifiers, air washers and wet air scrubbers Water softeners Filters bag, carbon, etc. Spa baths Dental equipment Fountains and water features Potting mix/mulch 4

5 WATER STORAGE TANK 5

6 6

7 7

8 Summary Develop a Water Quality Risk Management Plan (WQRMP) Confirm management. Structure to include contact details: duty holder responsible person competent persons/specialist contractors/consultants Undertake risk assessments including periodic reviews to confirm it s validity Compile a written scheme including: sampling methodology, frequency and locations Consequential actions as a result of the samples Review of Planned Preventative Maintenance currently undertaken and is it now suitable Action plan in event of an outbreak Communications plan who to contact in event of +ve samples or outbreak For more information Stuart Lloyd Stuart.Lloyd@jacobs.com Visit Retain records Keep hot water hot Keep cold water cold Maintain clean, scale and debris free water systems worldwide 8