Lan Chi Nguyen Weekes, P. Eng. – IEQ Operations and Maintenance & Management of Legionella in Water Systems

Air Date: 9-13-2019|Episode 557

This week on IAQradio+ we welcome Lan Chi Nguyen Weekes, M.A.Sc., P.Eng. Ms. Nguyen Weekes is currently the Director, Physical Resources of La Cité, a college in applied arts and technology in Ottawa, ON, Canada. She was the co-founder and partner of InAIR Environmental Ltd, an environmental consulting company from 1995 to 2018.

Ms. Weekes has over twenty-eight (28) years of consultation expertise on environmental issues, including the interaction between buildings and human health. Currently, she is working on the implementation of a Net Zero Carbone strategy on La Cité campuses, addressing the issue of Legionella in building water systems and assessing the impact of climate change on indoor air quality.
She is currently the chair of the ASHRAE Multidisciplinary Technical Group on Health and Wellness in the Built Environment. Recently, Ms. Weekes served as a project member of the Management of Legionella in Water System Committee of the National Academy of Science, Engineering and Medicine (NASEM).

Lan Chi Nguyen Weekes, P. Eng.

IEQ in Facilities Management & New Legionella Report

Lan Chi Nguyen Weekes was co-founder and partner in InAIR Environmental, Ltd. a widely recognized and respected Canadian environmental consulting firm. She currently is director of Physical Resources of La Cite´, a college in applied arts and sciences in Ottawa, ONT. Her current projects include: implementation of a Net Zero Carbon strategy on campuses, addressing Legionella in building water systems and assessing the impact of climate change on IAQ.

Nuggets mined from today’s episode:

La Cite´ is a small to medium size college. Lan Chi is responsible for 12 buildings on two campuses. Buildings include: residences, labs, classrooms, common spaces. In addition to a central heating plant, there are 600 heat pumps which need to be cleaned and maintained.

She is studying energy consumption where campus buildings are open between 06:00AM and 11:00PM.

The biggest IEQ problem she confronts is temperature. With extreme temperatures and high RH; controlling temperature is challenging in Canada. It’s impossible to please everyone.They do the best they can and due to budgetary issues must live with the consequences.

ASHRAE Multidisciplinary Technical Group on Health and Wellness in the Built Environment is helping to expand partnerships on the topics of health and wellness. The group is composed of: energy raters, researchers and government agencies. Using WHO and ASHRAE as resources, the group is working on defining health and wellness.

Lan Chi was a project member of the Management of Legionella in Water System Committee of the National Academy of Science, Engineering and Medicine (NASEM). Legionella is bacteria that naturally occurs in soil and freshwater. There are multiple strains of Legionella. Legionella grows in stagnant water and colonizes biofilm. Biofilm protects Legionella. The group is reviewing existing research on ecology of water and the diagnosis of illness.

  • There is a clinical and environmental disconnect on Legionella. Clinical and environmental data is not correlated. Environmental testing is infrequently done.
  • Patients are not being diagnosed early enough.
  • There are 52K-70K Legionella cases annually in the US.
  • Legionella is transmitted by water.
  • Legionella colonizes in water system components: mixing valves, vessels and distal pipes (situated away from the point of origin or attachment).
  • Character and quality of incoming water is a variable Legionella risk factor.
  • Viable Legionella bacteria can travel in air for miles.
  • Legionella goes dormant in cold water.
  • Immune compromised, young and elderly are at higher risk for Pontiac fever and legionella.
  • Pontiac fever is a milder form of Legionella.
  • Cases of Legionella are thought to be underreported by factor of 8X-10X. There is less or no reporting on the incidence of Pontiac fever.
  • Broadening existing policy and regulations, If EPA required minimal amounts of chlorine, registration and monitoring of public water systems.
  • Maintaining circulation and water temperatures of 60C at heat source and 55C are good preventative measures. Increases risk of scalding.
  • Its not always possible to control all the anti-Legionella parameters.
  • Considerations for cooling towers include: quality and character of incoming water, recirculation, blowdown, antimicrobials, etc.
  • Culture method is the gold standard for Legionella testing costs around $100.
  • Piping materials vary in their resistance to Legionella.
  • HVAC and water systems people are easier to train.
  • We don’t always know where Legionella is coming from in an outbreak and don’t know how to control it well.

https://www.nap.edu/login.php?record_id=25474&page=https%3A%2F%2Fwww.nap.edu%2Fdownload%2F25474

The CDC and ASHRAE also have starter Legionella documents.

Final Comments:

  • Facility managers are stuck with current building stock and budgetary limitations.
  • When all goes well facility management goes unnoticed, when there is a problem facilities management gets the blame.
  • Keep track of things!

Z-man signing off

Trivia Question:

Name the Philadelphia hotel in which the 1976 outbreak of pneumonia infection occurred?

Trivia Answer:

Bellevue-Stratford

Answered by Andrew Gondzur, Certified Safety Consulting, St Louis, MO

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