Download Legionella What Water Suppliers Need to Know

Legionella
What Water Suppliers
Need to Know
Paul J. Ponturo, P.E
NYSAWWA
2016 NY Water Event
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
How Is On-Premises Piping
an Issue for PWS?
• Opportunistic Pathogens in
On-Premises Piping
(OPPPs) a Major Source of
Waterborne Disease
• May be related to source
water, treatment or PWS
distribution system
• Some Opportunistic
Pathogens on EPA’s
Contaminant Candidate List
and UCMR4 discussion list
Water Research Foundation
WaterRF 4379
Waterborne Disease in US,
CDC
IN 2010 Legionella Exceeded All Other WBDOs
Note: in 2010 CDC Retrospectively Added Legionella to WBD Outbreaks
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
Legionella Outbreak- 1976
• Bellevue Stratford Hotel,
Philadelphia
• American Legion Convention
• About 4000 Participants
• 182 Cases- 149 Legionnaire
Delegates, 33 Non-legionnaires
• 29 Deaths
Cases
NYC, 2015
OCEAN CITY MD., 2011
OPERA HOUSE HOTEL
1994- Horizon Cruise Ship Whirlpool/ Sand Filter; 2006-British Cruise Outbreak
Las Vegas 2008-2012
ARIA, 2011- 6 illnesses
POLO TOWERS: Oct 2008 - positive hot
water - 300 guests re-located during
remediation
LUXOR, 4500 rooms 3 cases, 3 mo. 1 death
2014-15: Bronx
• Co-Op City- Dec. 2014- 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
What Else in Flint ?
Revealed 1/13/2016
• 87 cases, 10 deaths; 4x 2013 rate
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
What Is Legionella ?
•
•
•
•
Gram-negative bacteria.
42 known species
Legionella attaching
Enjoystowarm
water
environments.
an amoeba
Requires protozoa, other bacteria
to proliferate.
• Special media to cultured.
• ~ 2µm in length; in nutrientdeficient media, becomes thinner
Natural Habitat
• Common in fresh
and brackish water
environments
• Lakes, streams
have relatively low
numbers
• 1 inhaled amoeba
may be an
infectious dose
Legionellosis
• Defined as an infection with
Legionella
• Two manifestations:
–Legionella Pneumonia
(Legionnaires’ Disease)
–Pontiac Fever
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
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-CompromisedElderly, Immune-Suppressed, Chronically
Ill (COPD, Diabetics)
• Mortality 5-20%
Sources of Legionella
Infection
• Prime Reservoir- Stagnant, Warm Water
• Ideal Breeding Temperature Range:
77oF to 115oF.*
– *tempered domestic hot water issue,
pain at 106o , scalding at 131o F
• Main Outbreak Sources
– Cooling Towers
– Domestic Hot Water Recirculation
Systems
Cooling Towers
Cooling Towers
Cooling Towers and Traffic
Hot Water-Aerosolization
Source: AWT
So What does this
imply for PWS
distribution ?
Elevated Storage Tank
Stratification Issue?
Some Summer 2015 Tank Measurements
Optimum temperature range for legionella growth often reported as 77-115o F
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.
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
Susceptible Population
Immunocompromised, Smoker, Gender, Age
From NALCO
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
Unusual Legionella Cases?
Unusual Legionella Cases?
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.
Control Strategies, HW
Systems
• Maintain temperatures at > 140o F in all hot
water lines? Pipe scale, energy costs, scalding
potential
• Temporarily increase temperatures to > 140o F
in all hot water lines? Legionella growth/release
in some cases has spiked significantly after
temperatures reduced.
• Dosing Cl2 / chloramines? Potential for
increased corrosion.
• UV radiation? Regrowth downstream of unit.
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.
ASHRAE Standard
Development
• American Society of Heating, Refrigerating and
Air-Conditioning Engineers
• Standard 188-2015
– First Drafts- “Prevention of Legionellosis Associated
With Building Water Systems”
– Final Version- “Risk Management for Building Water
Systems”
WMP- Water Management
Plan
• ASHRAE 188- Implement WMP if (any one):
– 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
ANSI/ASRAE 188-2015:
Control Measures
• Applicable to :
– New Construction
– Siting
– Startup and Shutdown
– Inspections
– Cleaning and Disinfection
– 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
NYS Cooling Tower
Registration
• WHERE TO REGISTER: ON LINE (NY State)
– http://www.ny.gov/services/register-cooling-tower-andsubmit-reports
• WHERE TO REGISTER: ON LINE (NYC)
– https://a810efiling.nyc.gov/eRenewal/coolingTower_loginER.jsp
NOTE: NYC Cooling Towers Must Be Registered on
BOTH Sites!
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?
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.
What Culture Testing Results
Require
• 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
• If >1000 CFU/ml, institute immediate online
decontamination & review treatment program
– Retest in 3-7 days, get two consecutive retests,
consistent with steps above