Legionella What Water Suppliers Need to Know. Paul J. Ponturo, P.E NYSAWWA 2016 NY Water Event

Transcription

1 Legionella What Water Suppliers Need to Know Paul J. Ponturo, P.E NYSAWWA 2016 NY Water Event

2 Legionella An OPPORTUNISTIC PATHOGEN An infectious microorganism capable of causing disease in certain risk groups Opportunistic Pathogens cost the US economy $500 million dollars a year! Legionella is primarily a concern related to On-premises piping Legionella capitalizes on the built environment

3 Opportunistic Pathogens in On-Premises Piping (OPPPs) a Major Source of Waterborne Disease May be related to source water, treatment or PWS distribution system How Is On-Premises Piping Some Opportunistic Pathogens on EPA s Contaminant Candidate List and UCMR4 discussion list an Issue for PWS?

4 WaterRF 4379 Water Research Foundation

5 Waterborne Disease in US, CDC IN 2010 Legionella Exceeded All Other WBDOs Note: in 2010 CDC Retrospectively Added Legionella to WBD Outbreaks

6 EPA and PWS Regulations SWTR: if sufficient treatment is provided to control for Giardia and viruses then Legionella risks will also be controlled. Total Coliform Rule and the Ground Water Rule address bacteria, provide some control of Legionella. EPA October 2015 Draft - Technologies for Legionella Control: Scientific Literature Review

7 Legionella Outbreak Bellevue Stratford Hotel, Philadelphia American Legion Convention About 4000 Participants 182 Cases- 149 Legionnaire Delegates, 33 Non-legionnaires 29 Deaths

8 Cases NYC, 2015 OCEAN CITY MD., 2011 OPERA HOUSE HOTEL Horizon Cruise Ship Whirlpool/ Sand Filter; 2006-British Cruise Outbreak

9 Las Vegas ARIA, illnesses POLO TOWERS: Oct positive hot water guests re-located during remediation LUXOR, 4500 rooms 3 cases, 3 mo. 1 death

10 : Bronx Co-Op City- Dec Jan. 2015; 12 cases Power Plant Cooling Towers Morris Park- Sept. 2015; 15 cases, 1 death Melrose Houses- March- Sept. 4 cases Domestic hot water (positive samples). Water shut off, filters installed Opera House Hotel- July 2015; 133 cases, 16 deaths DNA Fingerprint Analysis - cooling tower

11 What Else in Flint? Revealed 1/13/ cases, 10 deaths; 4x 2013 rate

12 What Is Legionella? Gram-negative bacteria. 42 known species Enjoys warm water environments. Requires protozoa, other bacteria to proliferate. Special media to culture it. ~ 2µm in length; in nutrientdeficient media, becomes thinner

13 What Is Legionella? Gram-negative bacteria. 42 known species Legionella attaching Enjoys to warm an amoeba water environments. Requires protozoa, other bacteria to proliferate. Special media to cultured. ~ 2µm in length; in nutrientdeficient media, becomes thinner

14 Natural Habitat Common in fresh and brackish water environments Lakes, streams have relatively low numbers 1 inhaled amoeba may be an infectious dose

15 Legionellosis Defined as an infection with Legionella Two manifestations: Legionella Pneumonia (Legionnaires Disease) Pontiac Fever

16 Pontiac Fever Due to Legionella Exposure in an Immune Competent Person Symptoms: begin in hours to days; fever malaise, muscle pain, headache Self-limited (no medical treatment needed), lasts 2-5 days Up to 15% of population show antibodies

17 Legionella Pneumonia Onset: 2-10 Days After Exposure Symptoms: Moderate/severe Pneumonia; Fever: Non-Productive Cough, Hyponatremia (low sodium) Considered an Under-Reported Illness Primarily in Immune-Compromised- Elderly, Immune-Suppressed, Chronically Ill (COPD, Diabetics) Mortality 5-20%

18 Sources of Legionella Infection Prime Reservoir- Stagnant, Warm Water Ideal Breeding Temperature Range: 77 o F to 115 o F.* *tempered domestic hot water issue, pain at 106 o, scalding at 131 o F Main Outbreak Sources Cooling Towers Domestic Hot Water Recirculation Systems

19 Cooling Towers

20 Cooling Towers

21 Cooling Towers and Traffic

22 Hot Water-Aerosolization

23 Source: AWT

24 So What does this imply for PWS distribution?

25 Elevated Storage Tank Stratification Issue? Some Summer 2015 Tank Measurements Optimum temperature range for legionella growth often reported as o F

26 Biofilm, Sediment Issues Sediment accumulate in storage systems Biofilms develop on all moist surfaces- sand, silt and clays in tanks & reservoirs Sediment: 4-12 inches over 5 years Tank cleaning recommended at least at 5 year intervals.

27 Conditions That Increase Risk Pathogen Proliferation Stagnation Protozoa Biofilms Deposits ph Temperature Biocide use, non-use Aerosol Release Function/Use Design defects Wind Water flow From NALCO Susceptible Population Immunocompromised, Smoker, Gender, Age

28 Fixtures of Concern Water tanks & baths Spray taps Water recirculation systems for cooling Rarely used taps & showers (even at home) Misting equipment Dentistry tools Oil / water emulsions for lubricating lathes Mobile AC equipment with water

29 Unusual Legionella Cases?

30 Unusual Legionella Cases?

31 Control Strategies: PWS Change/increase disinfectant? May not be an effective on-premises control. Remove Assimilable Organic Carbon (AOC) and/or Biodegradable Dissolved Organic Carbon (BDOC) at the treatment plant? May work with other steps to control biofilm formation. Distribution System O&M? May work; cost, manpower commitment and success not clear.

32 Control Strategies, HW Systems Maintain temperatures at > 140 o F in all hot water lines? Pipe scale, energy costs, scalding potential Temporarily increase temperatures to > 140 o F in all hot water lines? Legionella growth/release in some cases has spiked significantly after temperatures reduced. Dosing Cl 2 / chloramines? Potential for increased corrosion. UV radiation? Regrowth downstream of unit.

33 Strategies for Control, HW Silver/copper ionization? Evidence of effectiveness; deposition corrosion? Point of use filters? Evidence of effectiveness, at least short term; requires maintenance, may harbor bacteria and inoculate downstream. Shower filters available: effectiveness? Change plumbing materials? Effectiveness? Control stagnation? Increased flow following retrofit may release biofilm growth Avoid metered faucets- May help. Increased water use possible.

34 ASHRAE Standard Development American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard First Drafts- Prevention of Legionellosis Associated With Building Water Systems Final Version- Risk Management for Building Water Systems

35 WMP- Water Management ASHRAE 188- Implement WMP if (any one): Plan Multiple units w/ Centralized Hot Water, Cooling Towers or Evaporative Condensers >10 Stories High Housing For People > 65 years old Facilities for Patients Staying Over 24 Hours Housing for People At-Risk Burns, Cancer, Transplants, Immunocompromised, Renal Disease, Diabetes, Chronic Lung Disease

36 Applicable to : New Construction Siting Startup and Shutdown Inspections Cleaning and Disinfection ANSI/ASRAE : Control Measures Monitoring- ex.: temperatures, disinfectant levels Water Treatment Responding to legionella incidents For: potable/domestic water systems, cooling towers, evap. condensers, public whirlpool spas, decorative fountains, misters, atomizers, air washers, humidifiers

37 NYS Cooling Tower Registration WHERE TO REGISTER: ON LINE (NY State) WHERE TO REGISTER: ON LINE (NYC) efiling.nyc.gov/erenewal/coolingtower_loginer.jsp NOTE: NYC Cooling Towers Must Be Registered on BOTH Sites!

38 NYS, NYC Cooling Tower Requirements 9/16/2015: Register; Initial inspection, testing, cleaning and disinfection as needed Inspect and test every 90 days Dip slide, HPC; Legionella analysis not required (except Nursing Homes and Hospitals) Maintenance program plan by 3/1/2016 ASHRAE 188 Referenced for cooling towers Hot Water Systems at Nursing Homes and Hospitals Certify compliance by 11/1/2016 NYSDOH, NYCDOH (enforcement?) Possible future: controls on domestic hot water chemical treatment?

39 Culture Sample Testing & Tower Disinfection Any owner of a building with a cooling tower must collect samples and obtain culture testing every 90 days, or in accordance with a maintenance program and plan obtained by the building owner. Immediate disinfection is required if culture sample testing demonstrates a need.

40 What Culture Testing Results If >10, but <1000 CFU/ml: immediate online disinfection Retest in 3-7 days; must get 2 consecutive retests showing acceptable improvement If > 10 but <100 CFU/ml repeat disinfection & retest If >100m, but <1000 investigate treatment program, and immediately perform online disinfection Require If >1000 CFU/ml, institute immediate online decontamination & review treatment program Retest in 3-7 days, get two consecutive retests, consistent with steps above