legionella risk management vs québec 2012 : past, present & future cpmx show

8/10/2019 Legionella risk management vs Qubec 2012 : Past, present & future CPMX show

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LEGIONELLA UPDATE

Qubec 2012:Learned, Done & to Do

Alain Trahan,

P.Eng.

20th of March

2014
http://cmpxshow.com/


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Cooling towers are the outside

heat sinks that exhaust the heat

carried by the air conditioning

cooling water circuit used inbuildings HVAC systems.

www.h2obiotech.com

What is a cooling tower?

Pump

HVAC

Air

conditioning


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www.h2obiotech.com

What is a cooling tower?


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Step 1:

www.h2obiotech.com

How it works

Step 2:

Magic of evaporation

Liquid water + energy Water vapor (with less energy remaining in the liquid)

Evaporative cooling


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www.h2obiotech.com

In the real dirty world

Dry air Dry air

WindBuilding fresh

air intake louvers

Building fresh

air intake louvers


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Simple definition:

An ubiquitous aquatic organism that causes Pontiac Fever

and Legionnaires disease (lung infection) if inhaled.

Thrives in temperatures between 77 and 122 F.

Travels from infected water source through aerosolized water

droplets.

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Legionella pneumophila

In the United States

10,000 to 20,000 people get infected by legionella every year.

Various studies have shown that some 40 to 60% of tested cooling towers contained Legionella.

Legionnaires disease mortality rate: 10 to 15% of those infected.

Cooling tower drift


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www.h2obiotech.com

Biofilms

Form on surfaces in aquatic systems.

Often resistant to biocides.

Monitoring is difficult.

Release organisms into bulk fluid.

Cost the US nation billions of dollars yearly in equipment damage, product

contamination, energy losses and medical infections.

Bacteria


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Qubec 2012: Source?


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www.h2obiotech.com

24% had Lp sp1!


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www.h2obiotech.com

Before: ASHRAE 62.1-2010

Specifies minimum distances between CTs vs

Air Intakes & Kitchen exhausts.

Not frequently applied especially by architect.

Mitigation : UVGI of fresh Air: always when high risk

occupants

Project the CT plume higher

Prevent food particles from reaching the CT.


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www.h2obiotech.com

Before: Pesticide Regulatory System

Pesticides need to be approved by HC for each

use with application guidelines.

Sellers & applicators need certification.

Reality : Provincial application.

No processes for CT biocides!

>75% non compliance in commercial blds for

concentration, contact time or hydraulics.


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www.h2obiotech.com

Before: Guidelines not Standards

ASHRAE 12-2000

AWT 2003 (2008)

CTI WTB-148 (2008)

CDC

Reality : Contradict each other.

Incomplete.

Control is left to water treatment as a last step

in general. Voluntary: doesnt work.


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www.h2obiotech.com

During

Hopes of official that situation would go away

by itself

High dose oxidizing biocide only.

CDC protocol ASSumes surfaces are clean &

circulation in whole system. Plan created during crisis.

Localisation & owners unknown.

No early public communication.


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www.h2obiotech.com

Lessons : Emergency planning

Have a plan of action: If this then that, etc.

What, Where, How, When, Who.

Work upstream of Legionella. Do not ASSume or Hope-away.

Legislate.


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www.h2obiotech.com

Lessons : Immediate steps

Stop the fans!

Ultra High Efficiency drift eliminators

Decontamination: Clean first to remove deposits. Circulate in whole system.

Fast acting biocide that keeps its efficiency

throughout the system.

Know system volume.

Analyze biocide concentration


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www.h2obiotech.com

Lessons : Involve outside experts

Interview with an official from the health agencyDSP followed by one with the building code

agency, RBQ


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www.h2obiotech.com

Lessons : Involve outside experts

Interview with an official the RBQBuilding CodeAgency


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www.h2obiotech.com

2013 Law: Form signed by Owner!


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www.h2obiotech.com

4 Dimensions of Risk Management


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Interrelation of the 4 dimensions

Law Description WaterTreatment

Hydraulic Solids Drift

402.1 Overwintering X X X X

402.2 Operational stops X X

402.3 Decontamination X X X X

402.4Corrosion, Scale,

OrganicsX X X

402.5 Schematics X X X

402.6 Water treatment quality X X X

402.7 Chemicals X

402.8 Mechanical Verification X X


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www.h2obiotech.com

Law 2013, phase I: the Good

LevelResult

(logs/L)Action

Normal < 4

Intervene 4 - 6Identify causes. Validate efficiency of new

measures.

Sanitary Risk > 6

Apply Decontamination. Identify root

causes & correct maintenance plan.Validate efficiency of new measures.

Test for Legionella pneumophila.

Legionella pneumophila Test concentration & Action Levels


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www.h2obiotech.com

2013 Phase I: Lessons

Plans : copy-paste

Schematics have or are:

Not up-to-date No flow speed or materials of

construction

No zones of stand-by operation Inspectors have no powers.


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www.h2obiotech.com

After: Coroners report, 2013-09


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After: Public Health Report


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www.h2obiotech.com

After: Media reports

Radio-Canada (CBC) had a 30

minutes piece that showed

delayed actions by officials.


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www.h2obiotech.com

After: Workers Health & Safety


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www.h2obiotech.com

After: Very Good CT Guide


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After: Excellent Full Day Training

Michelle Merchat, Climespace


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Law 2014, phase II: the Excellent

Specific cleaning step

independant from

decontamination Stop the fans if log 6 or more

Identification of sampling points


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www.h2obiotech.com

Law 2014, phase II: the Good

Mandatory testing for Legionella

p. every 30 days at most.


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www.h2obiotech.com


Law Description WaterTreatment Hydraulic Solids Drift

402.7a Sampling Points X

402.8 Chemicals X

402.9 Mechanical Verification X X

406 Log book X X X

407+

408Sampling procedures X X

417 4-6 logs Action Plan X X X X

418 Interfering flora X x

419 >6 logs, Action Plan X X X X


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www.h2obiotech.com


Law Description WaterTreatment Hydraulic Solids Drift

402.1 Overwintering X X X X

402.2 Operational stops X X

402.3 Decontamination X X X X

402.4+

402.9Preventive Cleaning X X X X

402.5Corrosion, Scale,

OrganicsX X X

402.6 Schematics X X X

402.7 Water treatment quality X X X


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www.h2obiotech.com

Beyond: What we do

Guidelines, Standards & Regulationsare a minimum

ASHRAE 188 methodology

Zero risk does not exist.Risk = Probability x Consequences

Multiple barriers: if one fails we avoid

an outbreak

Non-oxydising biocide measurement

On-site one hour Legionella

measurement!


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www.h2obiotech.com

Risk Assessment: beyond 62.1

Risk = concentration x duration. Occupants: long exposition.

High riks by Common Sense :

Close to ground, next to parking, bld entrance. Next to roof terrasse, balconies.

Adjacent to open windows.

Mitigation: UHE eliminator, lower C, continuous

or low tox or permanent biocide. Ex: Cu/Agionisation


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www.h2obiotech.com

Beyond: Flow Speed

Higher flow speed = less biofilm5+ fps up to 10 fps especially for

horizontal lines.

No dead legs: mitigation approach


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www.h2obiotech.com

Beyond: Deposits & Corrosion

Variable speed motors to avoid: Total evaporation deposits

Stray current corrosion.

Mechanical action to remove deposits. Zinc coatings are subject to white rust

corrosion.

Copper to steel surface ratio.

Is it clean?


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Back-Flow Preventer

Biocide means kill the biological

Some are banned from hospitals!


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www.h2obiotech.com

Water Meter & Level Control

Towers purge water but take no make-

up?!?

No moving parts Water meter.

Convert from continuous water MU to

ON-OFF.


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www.h2obiotech.com

Local Control: Average

Most common currentlyT compensated conductivity by dual

carbon probes

Flow switch, Pre-bleed, Bleed block,

Water meter input, permanent program.

Toroidal Conductivity :


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www.h2obiotech.com

Probe

Toroidal Conductivity :deposits & chem.

Valve

Ball valve, not solenoid :

plugging.

Meter

No moving parts & lowflow range.

Level

Chem inventory, water MU

control.

Wireless Meter, valve, level, etc.

pH+ORP Oxydizing biocides dosing.

Record

Conductivity, T,Meter, etc.


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Beyond: Internal Tank

Last in, last out: hydraulic factor closer to

1

PE instead of steel

Easy to access

Bottom does not favor accumulation

Affects biocide selection & risk strategy


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Thank you!

Alain Trahan, [email protected]

(514) 943-9044Prepared [email protected]
mailto:[email protected]:[email protected]


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legionella risk management vs québec 2012 : past, present & future cpmx show

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