New Rules on Legionella New Rules on Legionella PreventionPrevention

N. BangertN. BangertTS Workshop 2005, ArchampsTS Workshop 2005, Archamps

Table of ContentsTable of Contents• Diseases caused by LegionellaDiseases caused by Legionella• Living environment / Installations with riskLiving environment / Installations with risk• Cooling towers at CERNCooling towers at CERN

– Analysis and limitsAnalysis and limits– Preventive chemical treatmentPreventive chemical treatment– Corrective chemical treatmentCorrective chemical treatment– Annual preventive maintenanceAnnual preventive maintenance– Personnel protectionPersonnel protection– Conception and Follow up of Cooling TowersConception and Follow up of Cooling Towers

• ConclusionsConclusions

• Legionnaires’ DiseaseLegionnaires’ Disease– Pneumonia (collapse of Pneumonia (collapse of

respiratory function)respiratory function)– Incubation time: up to 10 daysIncubation time: up to 10 days– Mortality rate 5% to 30%Mortality rate 5% to 30%

Diseases caused by Legionella Diseases caused by Legionella = Legionellosis= Legionellosis

• Pontiac FeverPontiac Fever– Flue-like illness (fever and Flue-like illness (fever and

muscle aches)muscle aches)– Incubation time: few hours to 3 Incubation time: few hours to 3

daysdays

Living EnvironmentLiving Environment Warm stagnant waterWarm stagnant water

ShowersShowers

Installations with risksInstallations with risks

Cooling towersCooling towers

Whirlpool spasWhirlpool spas

Evaporative condensersEvaporative condensers

Cooling Towers at CERNCooling Towers at CERN2323Power: 1.25 MW to 70 MWPower: 1.25 MW to 70 MWVolume: 5 mVolume: 5 m33 to 4000 m to 4000 m33

LHC and SPS Cooling TowersLHC and SPS Cooling Towers

Cooling Tower

Cooling Towers at the Meyrin Cooling Towers at the Meyrin SiteSite

Cooling TowerFrench / Swiss Border

Analysis and LimitsAnalysis and LimitsFrequency now on a monthly basis Frequency now on a monthly basis (In the past 2-4 times per year)(In the past 2-4 times per year)

Preventive chemical Preventive chemical treatmenttreatment

100 000 UFC/l100 000 UFC/lStop, disinfection, cleaning, Stop, disinfection, cleaning,

purgepurge

Corrective chemical Corrective chemical treatmenttreatment

1 000 UFC/l1 000 UFC/l

0 UFC/l0 UFC/l

StopStop

Preventive Chemical Preventive Chemical TreatmentTreatment

• Continuous treatmentContinuous treatment– Anti-scaling reduces Anti-scaling reduces

formation of bio-filmsformation of bio-films• Weekly treatmentWeekly treatment

– Biocide targeted on Biocide targeted on general bio-general bio-contamination (algae, contamination (algae, fungi, bacteria)fungi, bacteria)

Corrective Chemical Corrective Chemical TreatmentTreatment• Amount of chemical depending on Amount of chemical depending on

level of contamination and volume level of contamination and volume of circuitof circuit

– Bactericide targets Legionella Bactericide targets Legionella bacteriabacteria

– Bio detergent detaches slime Bio detergent detaches slime off the surfacesoff the surfaces

Slime Surface

Annual Preventive Annual Preventive MaintenanceMaintenance

• Mechanical cleaning Mechanical cleaning – Basins, structures, …Basins, structures, …

• Purge of circuit Purge of circuit – not always practicablenot always practicable– time consumingtime consuming

• Disinfection of circuitDisinfection of circuit– Similar to corrective chemical treatmentSimilar to corrective chemical treatment

Personnel ProtectionPersonnel Protection• All personnel performing work in or All personnel performing work in or

close to cooling towers need to be close to cooling towers need to be properly trained regarding risksproperly trained regarding risks

• Zones to be signaledZones to be signaled

• Respiratory protective equipment need Respiratory protective equipment need to be carried in case of exposure to to be carried in case of exposure to aerosols or in cooling towers aerosols or in cooling towers

Conception and Follow up Conception and Follow up of Cooling Towers of Cooling Towers

– Free of dead end pipesFree of dead end pipes– Drop separators installedDrop separators installed– Good quality of supply water (Problems: Good quality of supply water (Problems:

SPS, STP18)SPS, STP18)– Accessibility for inspection and cleaning Accessibility for inspection and cleaning

givengiven– Technical documentation up to dateTechnical documentation up to date– Installation logbook put in placeInstallation logbook put in place– Follow up of water consumption and purgesFollow up of water consumption and purges

Methodical Risk Methodical Risk AnalysisAnalysis

Conclusion I: In PlaceConclusion I: In Place– Respect of frequencies and type of analyses Respect of frequencies and type of analyses

(100%)(100%)– Preventive and corrective chemical treatment Preventive and corrective chemical treatment

defined (and applied if necessary) (100%)defined (and applied if necessary) (100%)– Annual preventive maintenance (70%)Annual preventive maintenance (70%)– Completion and review of existing procedures Completion and review of existing procedures

about preventive and corrective activities about preventive and corrective activities (60%)(60%)

Conclusion II: To-Do-ListConclusion II: To-Do-List– Carry out a methodical risk analysis on all Carry out a methodical risk analysis on all

cooling tower circuitscooling tower circuits– Put warning signs in place Put warning signs in place – Implementation of a cooling tower LogbookImplementation of a cooling tower Logbook– Training of personnel intervening on and Training of personnel intervening on and

operating the cooling towersoperating the cooling towers– Update of hydraulic plansUpdate of hydraulic plans– ……

Conclusion III: EvaluationConclusion III: Evaluation– Hydraulic disconnection of north area Hydraulic disconnection of north area

cooling towers to SPS ringcooling towers to SPS ring– Hydraulic disconnection of STP18 from Hydraulic disconnection of STP18 from

SPSSPS– Put purge counters in placePut purge counters in place

Budget evaluation / Schedule : ?Budget evaluation / Schedule : ?

Questions ?Questions ?