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Drew Industrial Division Ashland Canada Corp Legionella Risk Management.

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Presentation on theme: "Drew Industrial Division Ashland Canada Corp Legionella Risk Management."— Presentation transcript:

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2 Drew Industrial Division Ashland Canada Corp Legionella Risk Management

3 ® Legionnaires’ Disease A potentially fatal form of pneumonia caused by the inhalation of airborne water droplets contaminated by Legionella pneumophila and other bacteria of the family Legionellaceae

4 ® Facts About Legionnaires’ Disease USA First cases in 1976 at Bellevue Stratford Hotel, PA; 221 people contracted LD, 34 died Severe respiratory infection simulating pneumonia An estimated 10,000 to 50,000 cases per year An estimated 1 percent of those exposed contract Legionnaires’ disease Estimated fatality rate is percent

5 ® Legionella legislation in Australia, NZ and UK forces customers to treat properly: –Prosecution and fines for noncompliance –Can shut down the system Legionella Regulations

6 ® Legionellosis Compared to Pontiac Fever Legionnaires DiseasePontiac Fever First Noted FormBacteriaVirus Attack Rate1 – 5 Percent95 Percent SymptomsFever, Cough, Muscle Aches, Chills, Headache, Chest Pain, Sputum, Diarrhea, Confusion Fever, Cough, Muscle Aches, Chills, Headache, Chest Pain, Confusion Effects on LungPneumonia, Pleural EffusionPleuritis, No Pneumonia Other Affected Organ Systems Kidney, Liver, Gastrointestinal Tract, Nervous System NONE Case-Fatality Ratio15 – 20 PercentNo Fatalities

7 ® Susceptability to Legionnaires’ Disease Age – The very young and 40 – 70 year olds Gender – Males are twice as likely to contract the disease than females Heavy Smoker Heavy Drinker Individuals with weakend immune systems – Cancer, AIDS, HIV positive Chronic Medical Problems – respiratory, diabetes, asthma, renal dialysis Certain Drug Therapies – corticasteroids or other immunosuppressive therapies Organ Transplants

8 ® Legionella Rod-shaped, aerobic organisms Found in natural and man-made water systems Up to 40 species identified Legionella pneumophila –Virulent strain causing Legionellosis

9 ® A source of Legionella Favorable growth conditions Aqueous aerosol Sufficient organisms to cause infection Susceptible individual Factors Determining the Risk of Contracting the Disease

10 ® Source of Legionella –Pervasive organism Conditions for growth –68   F (20  - 50  C) –pH 6-8 –Stagnant waters –A nutrient source Biofilms, organics Sediments, deposits Legionella Bacteria

11 ® Legionnella Bacteria Soil Derived Spore Former,Facultative Anaerobe (Maturing Biofilm) Iron and Amino Acids are Food Sources “CDC” Legionella Pnemophila –90% of All Outbreaks –82% are from Serogroup 1 –Others from Serogroup 4 and 6 –Outbreak Potential at ≥ 1000 CFU/ML

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13 ® Cooling towers Evaporative condensers Hot and cold water systems Taps and showerheads Humidifiers and air washers Spa and whirlpool baths Decorative fountains Systems Promoting Growth

14 ® Hot Water Requirements for Superheating of potable water systems; If the water is heated to at least 149 degrees F. Legionella die rapidly at 131 F and killed immediately at temperatures over 140 F. Water outlets are flushed for at least 30 minutes (Pittsburgh) or 5 min (CDC). It is recommended that the Hot water stored above 140 F circulation with the minimum return of 124 F.

15 ® Cold Water For cold water, the same as above can be done with heater or shock hyperchlorination ( >10 ppm) of chlorine in water and flush for at least 5 minutes. Additional protocols available and may be required on a local basis.

16 ® Legionella Testing General consensus is that testing is not effective Money better spent on biofilm control Many professional organizations provide guidance such as CTI, ASHRAE, etc.

17 ® The Role of Biofilms The prime culprit –Harbors Legionella and promotes growth Promotes growth of higher life forms such as Protozoa and Amoeba - act as a protective host Water Flow Surface Sessile Planktonic trapped particles providing nutrients embedded bacterial cells Reversible adsorption of bacteria (sec.) Irreversible attachment of bacteria (sec.-min.) Growth & division of bacteria (hrs.-days) Exopolymer production & biofilm formation (hrs.-days) Attachment of other organisms to biofilm (days-months)

18 ® Chemical treatment alone is not effective Minimization is dependent upon design, maintenance, contaminants, awareness and consistent implementation Effective Legionella management requires a “best practices” approach: A system that is properly treated, serviced and supervised In order to minimize Legionella growth: We know that…

19 ® Simplified Surface Growth

20 ® Field Study on Biofilm Growth PhaseTime Colonization15 Minutes Growth Detection2 Days Biofilm Formation (Exopolymer/ Minimum Biofouling) 5 Days Maximum Biofilm Growth (8 – 10 Cells Thick) 14 Days Fully Mature Biofilm Matrix31 – 40 Days

21 ® Three Dimensional Biofilm

22 ® We know that… Legionella risk minimization depends on the ability to control: GrowthDisseminationTransmission

23 ® Areas Promoting Growth Debris Biofilm Algae Biofilm

24 ® Questions?

25 ® Legionella Guidelines February, 2000 position paper –Background summary and guide –Platform for developing a more comprehensive, definitive program Guidelines were based on industry consensus prior to ACOP 2001 (UK-Regulated Approved Code of Practice) CTI position paper is an industry-developed consensus for Legionella best practices protocol. However, program implementation is subject to facility interpretation. CTI Protocol Establishes Baseline Program

26 ® CTI Protocol Halogen feed is required –Continuous halogen with free residual is preferred Use non-oxidizing biocide and/or biodispersant as needed –Intermittent halogen with higher levels of free residual is acceptable Non-oxidizing biocide specifically recommended Biodispersant may be required Testing and monitoring –Routinely monitor total bacteria using dip slides or agar Maintain less than 10,000 CFU/mLspecifically recommended –Routine Legionella testing is not recommended Only after suspected case or following sterilization Sterilization may be required –Maintain 5 ppm FAH for 6 hours minimum Specifically recommended based on various system indicators

27 ® Drew Industrial’s Best Practices Legionella Risk Management Program

28 ®  Comprehensive system assessment  Intensive microbiological treatment program  Sterilization and cleaning  Monitoring and control  Documentation Total System Approach: Five Areas of Activity and Performance

29 ® Comprehensive Water System Management

30 ® System survey –In-depth survey of system mechanical design and operating conditions –Utilizes established protocol, ex BSRIA- Building Services Research Institute Assoc. (UK) Identify, evaluate and rank specific factors associated with potential for microbiological growth and Legionella –Mechanical and chemical Determine risk minimization action plans  System Assessment

31 ® 1. Address non-chemical ways to improve microbiological control Remove piping dead legs Revise operating procedures Rotate idle equipment Use side stream filtration 2. Identify operating procedures, mechanical design and other factors that contribute to growth of Legionella Survey Provides Plan to Reduce Growth

32 Identify areas that promote growth or dissemmination of Legionella

33 ® Stagnant conditions Nutrients and conditions for growth Water and chemical treatment quality Water system mechanical conditions Location and exposure risk Critical Factors

34 ® Water flow is continuous No dead legs or stagnant conditions Basin and deck protected from sun No evidence of sludge, debris, algae Drift eliminators installed, functioning No evidence of aerosols, drift System not near health care, aged, residential facility Low number of people potentially exposed Halogen used Biodispersant/bio- dispersing biocide used Comprehensive water treatment program Automated biocide and chemical dosing Continuous automated monitoring, control “Ideal System”

35 ®  Intensive Microbiological Treatment Program Drew Industrial’s Best Practices Legionella risk management program requires an effective system approach that incorporates an intensive microbiological control program along with additional risk management actions

36 ® Cooling Technology Institute (CTI) position paper –Basic program approach Drew Industrial’s recommended intensive microbiological treatment program –Comprehensive treatment program incorporating the CTI-recommended actions plus several additional practices Intensive Microbiological Treatment Program

37 ® Drew Industrial’s program recommendations for minimizing the potential for growth of Legionella bacteria in cooling systems A comprehensive microbiological control program Includes all recommended CTI actions Includes CTI optional recommendations Provides more definitive guidelines Four protocols based on halogen feed Intensive Microbiological Treatment Program

38 ® Continuous feed for chlorine, bromine, BCDMH or stabilized bromine –Dosage: Recommended FAH and/or equivalent mV ORP with a minimum requirement of a measurable residual FAH For higher risk systems increase FAH residual as needed to control CFU level and biofilm Feed a supplemental organic biocide * –Recommend biocide be glutaraldehyde or an alternate biocide fed with biodispersant –Feed once per week or as needed to control biofilm * Alternative choices of non-oxidizing biocide should be based on toxicant evaluations (RPD) Continuous Oxidant Feed Protocol

39 ®  Comprehensive system assessment  Intensive microbiological treatment program  Sterilization and cleaning  Monitoring and control  Documentation Total System Approach: Five Areas of Activity and Performance

40 ® Intermittent Oxidant Feed –Chlorine, bromine, BCDMH or stabilized bromine –Minimum dosage: Hold FAH and/or equivalent mV ORP for a minimum of 2 hours each day Feed alternating supplemental organic biocides * –Recommend one biocide be glutaraldehyde or an alternate biocide fed with biodispersant –Feed an additional compatible organic biocide* –Alternate feed once per week  Intermittent Oxidant Feed Protocol * Dosages and alternative choices of non-oxidizers should be based on RPD results

41 ® Oxidation potential not affected by pH Selective oxidant No dissociation; does not react with water Does not react with amines, nitrogen compounds Highly effective against biofilm Chlorine Dioxide - A Selective Oxidant -

42 ® Continuous chlorine dioxide feed –Minimum dosage: 0.1 ppm residual ClO 2 or equivalent mV ORP Feed a supplemental organic biocide as needed based on biofilm control –Recommend biocide is glutaraldehyde or an alternate biocide fed with biodispersant * Feed once per week or as needed to control biofilm Continuous Chlorine Dioxide Feed Protocol * Alternative choices of non-oxidizing biocide should be based on RPD results

43 ® Intermittent chlorine dioxide feed –Minimum dosage: 0.5 ppm residual ClO 2 and/or equivalent mV ORP for a minimum of 2 hours per day Feed alternating supplemental organic biocides * –Recommend one biocide be glutaraldehyde or an alternate biocide fed with biodispersant –Feed an additional compatible organic biocide * –Alternate feed once per week Chlorine dioxide is also an effective supplemental biocide for process cooling systems where contaminants that increase bacterial growth are present. Intermittent Chlorine Dioxide Feed Protocol * Alternative choices of non-oxidizing biocide should be based on RPD results

44 ® Drew Industrial’s Best Practices program recommendation includes annual sterilization regardless of overall system indicators Procedure is per the CTI protocol –Annual on-line system hyperhalogenation Maintain 5 ppm FAH for 6 hours minimum, per the CTI process –Annual full system cleaning highly recommended Perform six months following hyperhalogenation If an off-line cleaning can not be performed, clean as possible on-line and follow with a second hyper- halogenation  Sterilization

45 ® Program monitoring FAH and/or ORP Maintain Total Bacteria Counts below 10,000 CFU/mL –Frequency as required to maintain performance Treatment levels, system parameters, corrosion, fouling, etc. Legionella testing Random Legionella testing is not recommended Testing is recommended only after sterilization Control schemes Automation improves performance and efficiencies Wide range of controllers available  Monitoring & Control

46 ®  Comprehensive system assessment  Intensive microbiological treatment program  Sterilization and cleaning  Monitoring and control  Documentation Total System Approach: Five Areas of Activity and Performance

47 Use of Proper Monitoring & Control Equipment is Critical! Microbiological Residuals, Corrosion, Scale & Biofouling On-line

48 ® ORP measures chemical oxidation potential Well documented sensor and control technology Provides amount of actual oxidation capacity of halogen regardless of form or dissociation vs. pH Relationship to FAH is dependent on individual system, chemistry conditions Each system has a specific ORP breakpoint and an effective level of ORP mV ORP PPM Halogen Fed Break point (example only System specific) ORP Control Range ORP Halogen Control

49 ®  Comprehensive system assessment  Intensive microbiological treatment program  Sterilization and cleaning  Monitoring and control  Documentation Total System Approach: Five Areas of Activity and Performance

50 ® Maintain complete, accurate logs – Biocide usage – Halogen tests and/or ORP log – Bacteria counts – Start-up and shut-down log – Log of operating procedures Monthly service inspection reports System disinfection logs Contingency plans  Documentation

51 ® Cooling systems are dynamic Biofilms DO exist within system System contamination DOES exist Some system designs present obstacles to effective Legionella control Despite good control, monitoring and response, some systems remain problematic. Why? Problem Systems?

52 ® For these systems… –Maintain an environment hostile to bacteria at all times –Continuously halogenate –Continuously feed biodispersant –Utilize reliable automation –Utilize ORP control –Regularly clean and disinfect –Rigorously inspect and maintain Problematic Systems

53 ® Surveying water system Evaluating key factors affecting growth Providing a comprehensive water management program Monitoring program for consistent control Documenting results and recording maintenance actions Maintaining Drew Industrial’s Best Practices Legionella risk management program Risks Associated with Legionella can be minimized by:

54 ® Legionella Risk Management Resources, Capabilities, Experience and Knowledge Research & Technology –Testing protocols, technical & microbiological details, non- standard program recommendations Best Practices Program Support –System assessment scheduling, technical support, literature, seminars, training materials Program Management –DREWTRAX™ and DREW SYSTEMS MANAGER™ data manager tools Field Expertise –Dedicated account representatives and consultants for program setup, training, monitoring, product selection Advanced Water Treatment Technology –Wide range of patented, high performance technologies for all applications including severely stressed conditions. Automation –Complete selection of feed, control and monitoring equipment Ashland

55 ® Drew Industrial’s Best Practices Legionella risk management program follows best practices designed to minimize conditions conducive to Legionella growth in cooling systems. As documented by CTI, these recommendations should not be interpreted as a guarantee to completely eliminate Legionella bacteria or any other particular pathogen. When properly applied, our program is effective in reducing the potential for water systems to contain planktonic bacteria, biofilm, and other conditions that can harbor and protect Legionella for extended periods.

56 ® Survey of Field Test Results In general it has been reported that 40 – 60% of Cooling Towers tested positive for Legionnella 794 evaluations performed 277 (35%) tested positive for Legionella Ranged from 1 to >9,000 CFU/ml

57 ® Detected Legionella Levels <1-1 CFU/ml2-9 CFU/ml10-99 CFU/ml CFU/ml >=1,000 CFU/ml 76 isolates24 isolates104 isolates55 isolates18 isolates 27.4%8.7%37.5%19.9%6.5% Based on 277 positive results 36.1% confirmed as <10 CFU/ML 26.4% confirmed as >100 CFU/ML

58 ® Legionnella Species Identifed

59 ® Response to a Positive Legionella Test Result Action Level 1 - (Detectable - <1 CFU/ML) –Risk Level - (Extremely Low) –Confirm current treatment program Action Level 2 - (1 - 9 CFU/ML) –Risk Level - (Low) –Increase frequency of current treatment to one additional dose of biocide for two weeks

60 ® Response to a Positive Legionella Test Result Action Level 3 - ( CFU/ML) –Risk Level - (Low to Moderate) –Increase treatment concentration and frequency to two additional doses of biocide weekly for two weeks Action Level 4 - ( CFU/ML) –Risk Level - (Moderate) –Increase treatment concentration and frequency to two additional doses of biocide weekly for 3 to 4 weeks –On-line halogen addition / additional organic dispersant maybe required

61 ® Response to a Positive Legionella Test Result Action Level 5 - ( CFU/ML) –Risk Level - (Moderate to High) –Hyperchlorination required possibly off-line –Use Halogen at 0.2 – 0.4 ppm FAH continuous or daily shocks of 0.5 – 1 ppm FAH for 2 to 4 hours Action Level 6 - (>1,000 CFU/ML) –Risk Level - (High) –Use halogen continuously at 1 ppm FAH for 6 hours, then 0.2 – 0.4 ppm FAH plus feed non-oxidizer every apparent retention time for 1 week will be required –Off-line sterilization using halogens at 5-10 ppm FAH for 6 to 24 hours, organics, and biodispersants may be required –Retest in 1 week

62 ® Action Levels Immediate response to positive test results On-line treatment requires a minimum of 14 days to produce results Unrealistic a system could be totally Legionella free

63 ® Thank You ® Registered trademark and ™ trademark of Ashland Inc. © 2001 Ashland Inc.


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