Presented by: Helen Cerra. October 11, 2012

Transcription

1 Presented by: Helen Cerra ChemTreat, Inc. October 11, 2012

2 ASHRAE Standard 188P Status/ review CTI Update Status/review t Bacteria Control

3 Quebec City, Quebec Edinburgh, Scotland Chicago, Illinois Blanes, Spain

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7 Standard 188 Prevention of Legionellosis Associated with Building Water Systems Draft Standard has had two public reviews Expect publication 2013

8 Purpose Present practices for the prevention of legionellosis ll i associated itdwith building water systems. Based on Hazard Analysis Critical Control Point (HACCP) Risk Management for US Armed Forces g NASA Food industry to control infectious organism transfer

9 Provides methods of risk management for preventing legionellosis ll i with centralized industrial and commercial building water systems Human occupied buildings. To be used by those involved din ownership/design/construction/installation/ mananagement/operation/maintenance and servicing

10 Build the team Survey

11 a) Multiple housing units with one/more central water heaters. b) Building more than 10 stories tall (includes below grade). c) Inpatient healthcare facility. d) Occupants ages >65 or receiving chemo for cancer or bone marrow transplant. e) One or more whirlpools and/or spas.

12 f) One or more aerosol releasing water features or devices (ornamental fountains, misters (atomizers), air washers or humidifiers) within it or located on premises. g) Incoming potable water total residual halogen = <0.5 mg/l as Cl 2.

13 Does the building have one or more cooling towers and/or evaporative condensers that provides cooling and/or refrigeration for the HVAC&R systems?

14 Process for Determining ASHRAE Std. 188 Compliance Document survey Form Survey Team Facility findings Develop HACCP Plan Yes Are there risk factors? No Repeat survey each year

15 Hazard Analysis Critical Control Point A PROCESS

16 1. Conducthazard analysis 2. Determine critical control points (CCP) 3. Establish critical limits for each CCP 4. System to monitor control of CCP 5. Corrective action if CCP not under control 6. Verify HACCP is working effectively 7. Documentation of procedures and record

17 Select a Team Process Flow Diagram Perform Hazard Analysis identify hazard Validation Criteria quantitative control Establish Validation Summary Establish Verification Schedule

18 Select a Team Person with an understanding of HACCP Owner/President/Administrator Facilities Chief/Manager EHS Hospital Infection Control Officer Risk Management

19 Identify end point uses of H 2 O Systems Potable Utility Develop two process flow diagrams Illustrate how water is received, delivered, processed Walk thelines!

20 Identify critical control points A point where control can be applied to prevent or eliminate a safety hazard or reduce it to an acceptable level. l Indicate on the process flow diagrams Establish critical control limits for each CCP

21 Develop Hazard Analysis Summary Document Process Step System Hazard Risk Signifcant Basis for Risk Control CCP Cooling Cooling tower Legionella yes Located near walk way Control MB, Corrosion, deposition. 2x/yr cleaning yes

22 Set up a monitoring procedure Set up frequency of monitoring Establish Corrective Actions when CCP deviates from the limit Validate CCP, limit, corrective action ex. CTI Guideline for MB Si Scientific reference, evidence Test for legionella

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24 Establish verification procedures Activities, other than monitoring that determines the validity of the analysis and control system and the system is operating according to the plan. Establish documentation and record keeping procedures

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26 Produce a single document of the plan Flow diagrams Hazard Summaries Monitoring schedule Equipment maintenance procedure Validation summary Verification schedule Plan for water disruption

27 Design, Maintenance, and Operations Controls Reference ASHRAE Guideline 12

28 Design, Maintenance, and Operations Controls Section 8.1 Potable Section 8.2 Cooling towers and Evaporative Condensers Section 8.3 Whirlpool spas Section 8.4 Decorative fountains, Section 8.5 Aerosol generating air coolers, humidifiers, and air washers

29 Reference eee ce ASHRAE Guideline 12 ASHRAE Handbook of Fundamentals Chapter 49, Service Water Heating Construction/renovation Startup/Shutdown Maintenance/ Monitoring temp and Cl Emergency Disinfections Hot/Cold water systems

30 Equipment Siting/Start up plan new Written system maintenance plan Written water treatment plan for control of microbiological activity, scale, and corrosion. Solids evaluation Shutdown and start up plan Disinfection i i procedures (2) Remedial on line and emergency

31 Reference ASHRAE Guideline 12 ASHRAE Handbook applications chapter on Water Treatment Cooling Technology Institute Association of Water technologies (AWT)

32 Reference state and local codes for public swimming pools and spas. If none apply, follow voluntary consensus std APSP 11 Standard for Water Quality in Public Pools and Spas.

33 No references Siting of equipment Contamination Access to pumps, filters, etc External heat sources Operation/Maintenance

34 Reference ASHRAE Guideline 12 Siting Contamination, Access New System Startup Maintenance/ Water treatment plan Shutdown and Startup plans Disinfectioni

35 Guideline: Best Practice for Control of Legionella Working on producing a Standard Still working release in 2013? Expect testing for Legionellag

36 Maintain continuous low level residual of free halogen (chlorine or bromine) If continuous halogenation not possible, intermittent use of halogen necessary for minimizing risk Bio dispersant can be used to aid in penetration and effectiveness of biocides Periodic addition of non oxidizing biocide as required to maintain clean conditions for both continuous and intermittent

37 Parameter Dipslides Agar Pour Planktonic Counts (Bulk Water) Sessile Counts (Surfaces) or Petrifilm Microscopic Exam <10,000 <10,000 No higher CFU/mL CFU/mL life forms <100,000 <100,000 No higher CFU/cm 2 CFU/cm 2 life forms Deposits NA NA No higher life forms

38 Ensures human health Lowers maintenance $$ Improves heat transfer Reduces corrosion (MIC)

39 Microorganisms Types Bacteria Fungi Algae Protozoa

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43 Pseudomonas biofilm

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45 Material T C (W/mK) Carbon steel Steel Stainless Steel (316) Copper Wt Water Biofilm ~ 0.63 Values from Characklis, William and Marshall, Kevin, eds., Biofilms, 1990 John Wiley & Sons, Inc.

46 Scale T C (W/mK) Calcium Carbonate Sherwood et al., 1975 Calcium Sulfate 2.31 Cli Calcium Phosphateh Magnesium Phosphate 2.16 Magnetic Iron Oxide 2.83 Biofilm 0.63 Characklis et al., 1981

47 Bacteria Control Oxidizing Biocides Nonoxidizing i Biocides id Biodispersants

48 HALOGENS HYPOCHLOROUS ACID, i.e. CHLORINE HYPOBROMOUS ACID, i.e. BROMINEIODINE HYDROGEN PEROXIDE CHLORINE DIOXIDE OZONE

49 Chlorine Most widely used biocide Cl 2 gas or liquid sodium hypochlorite Less effective at high ph and in the presence of ammonia Increased safety and discharge concerns

50 REQUIRES EDUCTOR FEED SYSTEM SAFETY AND HANDLING CONCERNS DEPRESSES WATER ph REGULATORY REQUIREMENTS

51 Available Cl % Liquid q - drums, totes, bulk One gallon = 1 pound of Cl 2 (gas) Sensitive to light/heat Relatively economical

52 100 % HOCl ph

53 SLOWER DISSOLVING 89% FAC Smaller Systems

54 MORE EFFECTIVE AT HIGHER phs LESS VOLATILE LESS CORROSIVE TO STAINLESS STEEL IMPROVED COPPER CORROSION INHIBITION IN AMMONIA CONTAMINATED WATER, BROMAMINES ARE BETTER BIOCIDES THAN CHLORAMINES DISCHARGE LIMITATIONS

55 Bromine Activated bromide (NaBr + Chlorine source) Liquid Stabilized Bromine Bromochlorodimethylhydantoin (BCDMH) Effective at high ph Bromamines effective Reduced halogen feed and discharge

56 Advantages Most cost effective bromine approach Improved effectiveness at high ph Biocidal in presence of ammonia Can vary ratios of fnabr with NaOCl or Cl 2 Disadvantages Two product feed (NaOCl or Cl 2 )

57 Clear, water-white liquid id Inorganic salt 38 42% NaBr Supplied in drums, totes, and bulk Not a biocide unless combined with an oxidizing agent (Cl 2, NaOCl)

58 NaOCl NaBr NaOBr NaCl NaOH HOBr REACT 12.5% BLEACH WITH 40% SODIUM BROMIDE 2 73 GALLONS OF 12 5% BLEACH TO ONE 2.73 GALLONS OF 12.5% BLEACH TO ONE GALLON OF SODIUM BROMIDE

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60 BCDMH DRY PRODUCT BROMINE AND CHLORINE DONOR 1:1MOLAR RATIO BROMINATOR

61 ONE DRUM, LIQUID 6.8% FAC COMPLEXED WITH A STABILIZER, WHICH ALLOWS IT TO BE FORMULATED IN ONE PRODUCT LESS PRONE TO PUMPING PROBLEMS COMPARED TO BLEACH DOESN T REQUIRE DILUTION WATER LESS VOLATILE

62 ADVANTAGES ENVIRONMENTALLY FRIENDLY DECOMPOSES TO WATER AND OXYGEN CAN DISPERSE SLIME MASSES DOESN T FORM THMs DOESN T ADD CHLORIDES DISADVANTAGES REQUIRES HIGH DOSAGE FOR CONTINUOUS CONTROL SOLUTIONS OF >30% ARE REGULATED BY THE DEPARTMENT OF HOMELAND SECURITY

63 A dissolved gas in water Unstable so it is normally generated on site Disagreeable odor, sweet & irritating, i i similar il to chlorine Rapid-acting bactericide Good oxidizer - oxidizes cell walls and membranes

64 Rapid kill rate at low ppm Broad range bacteria, fungi, & virus destruction Penetrates & sluffs biofilm, killing resident organisms Does not form tih trihalomethanes th (THMs) Does not react with ammonia or chlorinated organics Does not form hypochlorous acid or free chlorine Less corrosive than chlorine Remains effective across broad ph range Threshold odoris~ 0.1ppm

65 Sodium chlorite Chlorite + acid + bleach Chlorite + Hydrochloric acid Chlorite + Cl 2 gas Chlorite + ion exchange/catalyst Chlorite + Electrochemical ICA Trinova Sachets Stabilized chlorine dioxide (CL3000)

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67 ppm (as Cl2 2) Hypobromous Acid Stabilized Hypobromous Acid Hypochlorous Acid TIME (MINUTES) CHLORINE IS TWICE AS VOLATILE AS BROMINE

68 Nonoxidizing Biocides Isothiazolin Glutaraldehyde Dibromonitrilopropionamide - (DBNPA) Carbamate Quaternary Amines Terbuthylazine

69 Bacteria fungi, show activity to algae Slower acting not good for short residence times ph < 9 Deactivate with bisulfite Skin sensitizer

70 Broad Spectrum Bacteria, fungi, yeast Sulfate Reducing Bacteria Compatible with Oxidizers Not compatible with ammonia ph range 7 10 Faster acting at higher ph Deactivate with bisulfite

71 Broad Spectrum Fast kill Compatible with most system treatments Hydrolyzes to less toxic by products ph range 4 8 Increasing T at a ph will speed half life

72 Broad Spectrum Antifungal activity paper mills Stable up to ph of 12 Decompose at acidic ph Not compatible with oxidizing i agents

73 Surface active properties Clean surfaces Used for zebra mussel control Low in cost Used in combination with other biocides Foaming issues

74 Primarily algaecide Compatibility with oxidizers Control bacteria and algae in summer months Interferes with photosynthesis of plants Effective at cooling system ph

75 Biocide Selection Microorganisms ph Holding Time Scale/Corrosion Program System Contaminants

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