Bill McQuaid of ASHRAE on source-to-tap prevention strategy

Okay.

Chairman Shulman and members of the Committee on Health, thank you for the opportunity to testify today on New York City's response to the 2026 Legionella disease cluster.

My name is Bill McQuaid.

I've been a professional engineer in Pennsylvania for 28 years.

I'm also a fellow, a distinguished lecturer, and the immediate past president of the American Society of Heating, Refrigeration, and Air Conditioning Engineers, also known as ASHRAE.

ASHRAE standards and guidelines are used around the world to help building owners, engineers, public health officials, and operators reduce risk in the built environment, including the risk of Legionnaire's disease.

The central lesson from New York City's experience is that prevention cannot be limited to one device or one point in the system.

Cooling towers matter, and compliance with existing requirements is important, but a cooling tower approach has clearly not been enough.

Most Legionnaires disease cases are not part of large outbreaks.

In fact, the CDC has found that 96% of all cases are sporadic and not associated with an outbreak.

The thing that connects all of them is the potable water system.

Exposure can occur through many water-using components in that system, including building plumbing, showers, faucets, decorative fountain water features, hot water,

hot tubs, humidifiers, and many other aerosol generating equipment.

I heard the health department officials say that cooling towers are separate from the potable water system.

This is absolutely not correct.

Cooling towers get their water from the potable water system.

That is how it gets into the cooling towers.

It's a waterborne disease.

It does not come from the air.

That is why ASHRAE urges New York City to move toward a comprehensive source-to-tap strategy, just as we did 10 years ago when the outbreak occurred in the South Bronx.

A fundamental approach in disease prevention is the precautionary principle.

Yeah, Tom, as a can you summarize, please?

Yes.

This means that risk must be managed from the water source to the public distribution system into the building plumbing and finally to the fixtures and equipment where people may be exposed.

Municipal water quality, disinfection residuals, pressure changes, construction main breaks, treatment changes, storms, and building conditions can all have an influence.

Can all influence risk and must be managed.

Thank you very much.

And you can submit more extended testimony at testimony at council.nyc.gov.

Yeah, I've already done that.

Thank you.

John Mullen.

You may begin.

You may begin.