Legionella Control in Building Systems. Carl Schultz, PE National Healthcare Engineering Leader

Transcription

1 Legionella Control in Building Systems Carl Schultz, PE National Healthcare Engineering Leader

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3 Legionella Basics Bacterium that causes respiratory diseases such as Legionellosis and Pontiac Fever Present widely in water and soil The Philadelphia outbreak in 1976 attributed to hotel s air conditioning system Sickened 200 and killed 34 Transmission: aerosolized water droplets inhaled by a susceptible host

4 Favorable Conditions Temperature Grows and multiplies: 68 to 122 deg F Reproduces and thrives: 95 to 115 deg deg F takes 5 to 6 hours to deg F takes 32 minutes to deg F dies instantly Stagnation Scale, Sediment, Biofilms Presence of amoebae

5 Growth Influences Natural rubbers: washers, hoses, spray attachments Some plastics Wood (think large water tanks) Carbon: think twice about providing carbon filtration at ice machines! Carbon also removes chlorine from the water!

6 Why is this topic important? Health of Building occupants New guidelines Preventable Increasing risk of litigation

7 Cases up 400% since 2000

8 Health of Building Occupants More than 20 outbreaks were reported in 2015 resulting almost 5,000 diagnosed cases of Legionnaire s disease 12% of population is susceptible Heavy cigarette smoking, chronic lung disease, weakened immune system from cancer, diabetes, kidney failure, organ transplantation

9 Wrongful Death Suit 53 year old Allstate insurance employee contracted Legionnaires Disease in Dec 2004 Died in January 2005 Used bathroom on ground floor of office building regularly Coworker testified that he saw him splash water on his face Defense said he drank alcohol and smoked cigarettes Summary judgement against plaintiff family Absence of statute, regulation, or industry standard

10 Barrow-in-Furness Case 2002 outbreak from cooling tower 7 deaths and 188 cases of illness A senior architect with the government council was charged with 7 counts of manslaughter Technical Manager for government was fired Architect was found not guilty but she and her employer paid significant fines Contractor settled for 1.5M British Pounds

11 Legionella Laws Bronx Legionnaires Outbreak summer deaths: Opera House Hotel cooling tower NYC Local Law 77: Registration, inspection, cleaning, disinfection, testing of all towers Owners: annually certify in compliance of law $25,000 fine, 1 year in prison for non-compliance New crisis = new laws, regulations Standards and guidelines used to craft laws and regulations

12 ASHRAE Standard 188 Prevention of LegionellosisAssociated with Building Water Systems Much of this document is more useful to building owners and operators Gives insight on what O&M staff will need to be doing and how to design accordingly Presents opportunities for consultants: Mapping water systems Designing remedies for proper system operation Writing risk mitigation plans

13 ASHRAE Standard 188 Determining building Risk Characterization Conducting a hazard analysis Determining critical control points & limits System monitoring Establishing corrective actions Verification and documentation

14 Standard 188: Risk Characterization Multiple housing units with common water heater(s) Building with more than 10 stories Inpatient healthcare facility Occupants over 65 or receiving chemo or bone marrow transplant Whirlpool, spa, or aerosolizing water feature Less than 0.5 ppm Cl 2 on incoming water supply

15 ASHRAE Guideline Minimizing the Risk of Legionellosis Associated with Building Water Systems Should be updated soon and the information will be used to supplement Standard 188 More practical guide for the building engineer

16 ASHRAE Guideline Recommended Treatment (Control Limits) In healthcare facilities, nursing homes, and other high risk facilities: Cold water stored and distributed at temperatures below 68 deg F Hot water stored above 140 deg F HW circulated with a minimum return temperature of 124 deg F

17 VA Plumbing Design Manual Washington DC office Updated primarily for Legionella Mitigation Impetus: 6 deaths at Pittsburgh VAMC in 2011

18 VA Plumbing Design Manual Physical Security Manual: 4 day water supply Entering potable water monitored for: Pressure, temperature, ph, oxidant levels Temperature measured throughout hot & cold water systems Hot & coldwater to be continuously recirculated

19 VA Plumbing Design Manual Minimization of dead ends and fixture run-outs DHW must be available within 15 seconds Run-out volume and length - International Green Energy Code:

20 Limiting Pipe Volume In Patient Rooms

21 VA Plumbing Design Manual Taps for booster heater for thermal eradication and shock chlorination No PVC for sanitary due to thermal eradication 30 minutes at 160 to 170 degf Water heaters to develop 180 degf TMV to have bypass

22 New Hospital Case Study VA Medical Center, Louisville, KY million SF Mission critical design

23 Chill your Cold Water?

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27 Renovation Case Study VA Medical Center Clarksburg, WV Domestic Water System Upgrades Hand-over-hand pipe investigation Mapped the entire domestic hot and cold water systems: 450,000 sf Identified dead legs and abandoned piping Designed remedies Legionella management program

28 Field Investigation HEPA Containment Cart Infection Control Risk Assessment (ICRA) Work with Infection Control Staff

29 Piping Details

30 Building Automation System Domestic hot water supply and return systems Graphic displays Temperature sensors Trending Alarm

31 Water Balancing Plumbing professionals need to craft a detailed water balancing specification similar to the HVAC colleagues Contractor needs to have credentials and provide a report at the end of the balancing exercise This will ensure that hot water is circulating properly throughout the facility

32 Commissioning Water heating equipment: 140 Deg F or above ASSE 1017 Master Mixing Valve Point-of-use ASSE 1070 mixing valves at lavatories Shower temperature limit stops Recirculation systems: System temps above 124 deg F

33 Energy Codes 120 deg F storage temperature Cycling of circulation pumps and heat trace based on occupancy schedule or demand Don t have to comply if it affects health/safety International Energy Conservation Code Maximum allowable pipe length method Maximum allowable pipe volume method Veterans Administration has adopted similar pipe volume restrictions

34 International Energy Conservation Code Maximum allowable pipe length method 2 foot maximum runout to a public lavatory faucet with 1/2 HW (from the nearest source of heated water) Maximum allowable pipe volume method Volume from the nearest source of heated water to a public lavatory faucet is 2 ounces. A 3/8 pipe has 0.75 ounces/ft.

35 2015 IECC Compliant

36 Take Aways There is going to come a day when people and organizations will be held to a higher level of accountability for: Designing Constructing Operating Maintaining Domestic hot water systems

37 Take Away for Critical Facilities DHW distribution: 130 deg F minimum Generation and storage: 140 deg F minimum DHW return: 124 deg F minimum Use of TMVs throughout Extend return lines DEEP into system Minimize dead legs & stagnant area

38 Other Considerations Create schematics of water systems Include temperature and chlorine monitoring Access to water hammer arrestors, trap primers Building Automation System Water balancing Commissioning

39 Other Approaches Copper-Silver Ionization Optimal concentration of ions is not know (ASHRAE Guideline ) Was used at Pittsburgh VAMC where 6 died of LD Chlorine Dioxide Used by municipal water providers Secondary treatment in buildings requires EPA approval Has been used in UK and continental Europe

40 Questions? November 30, 2017