Drink it or Sniff it? IHEEM Technical Platform May 2014 Seminar - - PDF document

15/05/2014 Water Hygiene Centre 1

Drink it or Sniff it?

IHEEM Technical Platform May 2014 Seminar

Legionellosis Risk Assessment

Dr Nick Hill, Research & Development Director, Water Hygiene Centre (Chair of the IHEEM Water Technical Platform)

Content

• Some of the regulations don’t work;
• Beware of the Public Relations Officer;
• Get risk into perspective;
• Understand inherent and actual risk;
• Rainwater recovery is a fashion;
• Stones always have beetles under them;
• If you use a contractor as a consultant, it serves

you right;

• PFI Change Control Notices are great for door

handles.

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Drink it or Sniff it?

• TVC count of 10 cfu/mL is 10,000 cfu/L.
• This TVC 10,000 cfu/L count is relatively

boring, but..

• A Legionella count of 10,000 cfu/L is “quite

interesting”.

Small Bag of Acid Tennis Court

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HSG 274, Part 2 – Draft for Comment

• Water components that

may increase risk of colonisation:- – TMVs – Proximity operated taps – Flexible hoses

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What is ALARP?

• It will depend on the risk
• There will be an ALARP for design, monitoring,

maintenance, etc

• It’s a balance of risk, cost and difficulty
• It’s not as low as possible

Which is higher risk?

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Now which one is riskier?

High active risk Low active risk

Which is higher risk?

Low inherent risk High inherent risk

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Now which one is riskier?

High actual risk Low actual risk

Which is higher risk?

Cold water storage Cooling tower

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Now which is riskier?

Cooling tower internals Cold water tank internals

Now which is riskier?

Office block Leukaemia ward

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Now which is riskier?

Leukaemia ward Office block

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Abstractions – England and Wales

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Legionella Testing as Part of Routine Risk Assessment?

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Actions Taken

• Local cleaning and disinfection
• Tanks cleaned and disinfected
• Flushing
• Resampling
• Wider sampling

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19oC 15oC

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Showers Summary

• Failed to identify that one of two shower

heads was not being used, ie stagnant

• Failed to identify multi-function shower head,

with potential stagnation

• Failed to recognise that one of the supply

tanks to the shower was stagnant

• Incorrect recommendations – repeated

sampling and disinfections not the answer!

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• Recommendations for Calorifier 1

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• Recommendations for Calorifier 1

Recommendations for Calorifier 1

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Recommendations for Calorifier 1

• Failed to notice 2 out 3 shunt pumps

upside down

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Their picture… My picture….

?

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Are we sure what calorifier temperature should be?

Calorifiers Summary

• Inappropriate recommendations for DHW

testing for Legionella

• Did not spot shunt pumps upside down
• Did not spot DHW flow restriction
• 2 different recommendations for calorifier

temperature – both wrong!

• Failed to take any DHW return temperatures

(presumably don’t have a contact temperature probe?)

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PFIs and the Change Control Notice

• Can be too slow when

there is imminent danger;

• MHSWR – cooperate

and coordinate?

• Acute hospital with the

tank support defect;

• Alert issued November

2013, not resolved by April 2014.

Content

• Some of the regulations don’t work;
• Beware of the Public Relations Officer;
• Get risk into perspective;
• Understand inherent and actual risk;
• Rainwater recovery is a fashion;
• Stones always have beetles under them;
• If you use a contractor as a consultant, it serves

you right;

• PFI Change Control Notices are great for door

handles.

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Drink it or Sniff it?

IHEEM Technical Platform May 2014 Seminar

Legionellosis Risk Assessment

Dr Nick Hill, Research & Development Director, Water Hygiene Centre (Chair of the IHEEM Water Technical Platform)