Applying IH Principles to Legionella Prevention · 2019-04-25 · Legionella Prevention Rob Moon,...

Applying IH Principles to Legionella Prevention

Rob Moon, CIH, CHMM

Director, Office of Environmental Health and Safety

Wayne State University

Timeline (1/3)

• May 26, 2018• A WSU employee diagnosed with Legionnaires' disease. The individual is

under a doctor's care. While it is very unlikely that this person contracted the disease from a campus source, through an abundance of caution we will check the building for a potential source.

• June 6, 2018 • Preliminary results have identified cooling towers on three campus buildings

that have tested positive for legionella. Remediation in those three towers began immediately this evening using the prescribed disinfection process.

Timeline (2/3)

• June 29 – July 1, 2018• Preliminary verbal results from last week's testing of the cooling towers in the

Towers Residential Suite indicate elevated levels of Legionella bacterium. The remediation team is already working on it. The cooling tower on the Towers Residential Suites will remain shut down until we receive results confirming non-detectable levels. As a result, we remain unable to provide air conditioning in that building. Guests scheduled to stay in the Towers in the meantime are being provided other accommodations.

Timeline (3/3)

• July 2, 2018• We recently learned that two employees of a contracting firm working on

construction of the new Anthony Wayne Drive Apartments have been diagnosed with Legionnaires' disease. …our comprehensive plan of testing and remediation is continuing.

• July 16, 2018• In the case of the Towers Residence Suites, we have decided to replace the

rooftop cooling tower, which will require several more weeks before the building will be reoccupied.

• Waterborne pathogen

• Biofilm is usually the host / food source

• Cooling towers

• Also domestic plumbing, misting devices, pools, spas

• Temperature range for growth: 70 -120° F (optimal 98-110° F)

• Survives up to 160° F

• Under 70° F, it does not reproduce

What is Legionella?

Legionaries' Disease

6

Waterborne

Temperature

Disinfection Level

Water age /

stagnation

Scale

Aerosolization

- Wind

- Source

- Humidity

Immunocompromised

Elderly

Smokers

Entry Growth Transmission Susceptible Host

Minimize Risk of Disease by Controlling Factors Affecting Growth & Transmission

LD Cases - Statewide

Reported cases of legionellosis increased 364% from 2000 to 2016

61 cases YTD in MI (as of 4/6)

0

100

200

300

400

500

600

700

2014 2015 2016 2017 2018

LD Cases

Additional Communication / External Interaction• Daily internal calls with WSU Crisis Management Team

• Weekly calls with Detroit HD, MDHHS, MIOSHA

• MIOSHA inspection

WSU Response• Notification / full transparency with Detroit and MI Health Departments,

MIOSHA• Regular phone calls, providing data

• Collected ~1200 samples for Legionella

• Upgraded cooling tower ORPs – automated chemical addition / notification of problems

• Added second non-oxidizing biocide (glutaraldehyde), started using bromine (less pH-dependent oxidizing biocide than Chlorine)

• Efforts were critical – 100+ LD cases in Michigan from late Sept. to late Oct.

MIOSHA - ASHRAE 188-2015

• OSHA requires employers to furnish a place of employment free from recognized hazards that are likely to cause death or serious physical harm (referred to as the "General Duty Clause").

• OSHA may enforce the General Duty Clause for hazards when there is no specific standard (e.g., exposure to Legionella).

• OSHA provides references from multiple organizations (CDC, ASHRAE) that provide recommendations for controlling Legionella. Employersmay demonstrate compliance with these standards as evidence that they are compliant.

Introduction to the Standard• Approved by ASHRAE & ANSI 2015

• 10+ years in the making

• First International Standard on Legionellosisprevention

• Closely aligned with the WHO Legionelladocument from 2007

• 2018 Edition now available

The Process

• Control Locations• Control Measures• Control Limits

• Verification• Validation

Water

Other standards

• CDC Toolkit

• CMS Memorandum

• New York City & New York State

• AIHA

AIHA Guideline (2015)

• Assessments:• Routine

• Investigative

• Validation required (Legionella sampling)

• Provides recommended responses based on quantitative lab results

Water Management Team Membership• Facilities / maintenance

• EHS

• Chemical suppliers

• Consultants

• Faculty

• C-Suite

• Housing

• OGC / Communications / Medical / Other Risk Managers

Chemical Control

• Corrosion

• Scaling

• pH

• Blowdown (recirculation) rate

• “Dead legs” – including operational, drains, pump circuits

WMT - Determine and Request Resources

• Funding for CT chemicals

• Infrastructure (cooling tower chemical sensors, pumps)

• Testing equipment (real time chemical monitoring)

• Laboratory analysis

• Off-season cleaning and maintenance

• WMP Development

WMT - Determine Personnel Needs

• Operational• Maintain CTs, chemical levels

• Maintain pumps

• Monitor chemical supply, etc.

• Flush dead legs, cycle pumps

• Respond to test results / observations• Mechanical problems, low biocide, HPC “dipslides”, Legionella

• Troubleshoot, repair, shock, clean

Program Verification / Validation Needs

• Cooling towers• Measure biocide

• Collect samples for lab analysis – Legionella

• Corrective action recommendation and verification

• Other• CT-related safety training

• Design review

• Review literature, interface with experts

• Communications / data tracking

WSU Response (Ongoing)• Off-season cooling tower cleaning, repair and maintenance

• “Shoulder season” cooling tower operating procedures

• Continue dead leg flushing / removal

• Refining ORP sensor settings

• Frequent testing, enhancing response procedures to proactive indicators

• Design review – ease (and safety) of cleaning and sample collection

Other thoughts

• Alternatives to open loop water-cooled systems.

• Municipal Water Suppliers. Involvement “past the meter”?

• Water Conservation / LEED

• Cooling tower manufacturers

• Safety for maintenance / EHS

Acknowledgements

Phil CunninghamAVP Research Integrity

Carol DarginDir, Bldg Engineering

Christine GreenDeputy Chief of Staff

David JessupPathcon

Shawn McElmurryCollege of Engineering

Peter MillerEldon Water

Beth OlsonEHS Specialist

Steven PecicSr. Dir. Facilities

Brian SheltonPathcon

Steve SyrettEldon Water

Gerry TilsonStudent Aux Services

Michael WrightChief of Staff

AND MANY OTHERS!!