HSE Legionella Water Treatment Contractor Inspection Programme

Published on 05/15/2020 | by Waterline Admin

As featured in waterline Spring 2020

HSE Legionella Water Treatment
Contractor Inspection Programme

By Duncan Smith, HSE

Between 2012 and 2018, HSE undertook a series of proactive interventions to reduce the risks from wet evaporative cooling systems. These interventions were impactful, as the degree of non-compliance reduced over time. However, it was evident that a small number of dutyholders struggled to achieve sustained compliance due to poor or inadequate service provision.
In early 2019, HSE carried out a novel intervention targeting Water Treatment Contractors (WTC). The aim of the intervention was twofold: to raise standards via advice, education and promotion, and also to take enforcement action where it was appropriate to do so (in accordance with HSE’s Enforcement Policy Statement and Enforcement Management Model). HSE recognise raising the standards amongst WTCs should have significant gearing effect and should also assist dutyholders to achieve sustained compliance.

Intelligence from the previous wet evaporative cooling system interventions was used in the targeting of WTCs. Head office visits were undertaken to examine the policies and procedures involved in the planning and delivery of services, as well as on demonstration of competence.
Inspectors used bespoke operational guidance drafted for the intervention. This required Inspectors to probe specific aspects of service provision and also ensuredconsistency of approach.

Main Findings
Of the 24 inspections completed, greater than 1 in 3 WTCs were judged to be in material breach of law and it was necessary for the Inspector to write to the WTC to secure improvement.
By far and away the single biggest issue found was in relation to the adequacy and suitability of respiratory protective equipment (RPE) required for system cleaning when there was a risk of aerosol generation during activities such as jetwashing. Material breaches relating to RPE accounted for more than 1 in 2½ of all the breaches found and these issues were evident at more than 1 in 4 of all WTCs inspected.
Other highlighted concerns related to the Legionella risk assessment process, cleaning techniques and training/competence of staff.
A detailed report on the intervention is being prepared and will be added to the Legionella Webpages on the HSE website soon.

Whilst the results of this intervention do not indicate the need for a larger intervention at this time, however, the quality of WTC service provision should be kept under review by HSE. Existing advice and guidance on RPE for cleaning activities needs to be more prominent and disseminated more widely within the Legionella control industry. Appendix 6 of HSG53 (Respiratory protective equipment at work. A practical guide: www.hse.gov.uk/pubns/priced/hsg53.pdf) advises that a particulate respirator with an assigned protection factor (APF) of 20 would be the minimum acceptable protection level for airborne micro-organisms and that for cooling tower cleaning using high-pressure hoses, a powered respirator with full facepiece or hood/blouse might be the most suitable because of the work rate and wet conditions. Further guidance can also be found in various COSHH Essentials direct guidance sheets:

Diary Dates & Events

Grime Scene


Following on from the successful Grime Scene competition, we have decided to continue the theme for another year, but with a twist. This year, we are asking for photographs of the grimiest pictures you can find accompanied with another photograph of how the ‘scene’ has been improved by your maintenance or cleaning.

We will display the photographs in each of the Waterline editions throughout 2024. The ‘most improved’ picture will be chosen by WMSoc members via an online vote. The winner will receive a £25 Amazon Gift Voucher after the Winter 2024/25 edition has been published.

Please send your photographs to:

Product & Service Spotlight

Introducing B & V Chemicals' new film forming amines for closed circuits and steam boilers.

Product Launch: Film forming amines.

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Plus - environmentally friendly, offering a greener alternative to traditional treatments.

Contact us on ownlabel@bvwater.co.uk for further information.

How the NEW SolidTek® Biocide Feeder Package will BENEFIT YOU

SolidTek® has launched its NEW Biocide Feeder which is functional, compact, and environmentally-friendly.

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Charge with product in under 5 minutes without isolation from the system.

Product calculators and tech support available.

Lovibond MD640 Photometer (PTSA & Fluorescein capable)

Product Spotlight Drop Test Kits

How many times have you heard … ‘we’re not sure what the system volume is’. A common problem which can be expensive - wasting chemical over dosing, or underdosing so the treatment is ineffective (i.e. shock dosing a biocide). The MD640 photometer has PTSA & Fluorescein capability built in. Simply use our System Checkers to add to an unknown system and read a PTSA or Fluorescein levels to accurately identify the system volume.

The Hydrosense PRO range


The Hydrosense PRO range pioneers Legionella pneumophila detection, the cause of over 97% of Legionnaires’ disease outbreaks, by identifying all the serogroups 1-15 of this dangerous Legionella species. This easy-to-use, highly sensitive test uses unique filtration, offering a three-line test result that distinguishes between serogroup 1 and serogroups 2-15 within 25 minutes. The water test has a level of detection of 100 CFU/L and swab tests detect 200 CFU per swabbed area, providing crucial, rapid insights for water safety management.