loader from loading.io

488 Managing Legionella with confidence: A Conversation with Patsy Root

Scaling UP! H2O

Release Date: 08/07/2026

503 Pinks and Blues: Beyond Industrial Water Week 2026 show art 503 Pinks and Blues: Beyond Industrial Water Week 2026

Scaling UP! H2O

 Industrial Water Week 2026 has ended, and Trace Blackmore, CWT, challenges listeners to carry its focus on learning and mentorship into the rest of the year. This Pinks and Blues episode combines reflections on IWW26 and the AWT convention with listener questions about AI and professional development.  Give continued learning a place on your calendar  Trace proposes a specific challenge: choose one of Industrial Water Week’s five focus areas and schedule 30 minutes to improve your understanding. Those areas are pretreatment, boilers, cooling, wastewater, and careers. ...

info_outline
502 Industrial Water Week 2026: Careers Friday show art 502 Industrial Water Week 2026: Careers Friday

Scaling UP! H2O

 Experienced water treaters carry knowledge that the next generation needs. For Careers Friday, Trace Blackmore, CWT asks them to pass it on. The Industrial Water Week 2026 finale connects industrial water treatment careers with mentorship, practical training, and curiosity. Pass on the reasoning behind the work Trace describes a mentor as someone you can call when a system presents a problem you cannot explain. Learning from another professional’s challenges, mistakes, and experience helped him solve problems and later mentor others. He also addresses professionals preparing to retire....

info_outline
501 Industrial Water Week 2026: Wastewater Thursday show art 501 Industrial Water Week 2026: Wastewater Thursday

Scaling UP! H2O

A wastewater inspection appeared to expose a failed treatment program—until Trace checked where the sample had been collected. For Industrial Water Week 2026: Wastewater Thursday, Trace Blackmore, CWT, connects correct sampling, water reuse, and careful troubleshooting with the decisions water treaters make every day.  Check the sample location before drawing conclusions  In an early-career account, a plant operator faced a threatened shutdown after an inspector’s sample produced out-of-spec results. Trace reviewed logs, spoke with the engineer, and tested two locations. The...

info_outline
500 Industrial Water Week 2026: Cooling Wednesday show art 500 Industrial Water Week 2026: Cooling Wednesday

Scaling UP! H2O

Cooling Wednesday brings a practical reminder: correcting a treatment problem requires understanding what caused it. For Industrial Water Week 2026, Trace Blackmore, CWT, celebrates Episode 500 with lessons on cooling tower foam, biocide feed verification, Legionella risk, and unexplained chilled water loss.   Start with the feed history  When a cooling tower produces enough foam to spread across the property and trigger low water shutdowns, Trace begins with the biocide feed logs. He compares the chemical remaining in the tank with calculated consumption and finds evidence of...

info_outline
499 Industrial Water Week 2026: Boiler Tuesday show art 499 Industrial Water Week 2026: Boiler Tuesday

Scaling UP! H2O

Boiler Tuesday is a reminder that industrial water treatment exists to protect heat transfer efficiency. For day two of Industrial Water Week 2026, Trace Blackmore, CWT, connects feedwater preparation, condensate quality, and treatment distribution to the everyday decisions that keep steam systems working.    Feedwater quality sets the stage  Trace starts with a practical measure of boiler performance: how much heat from the flame reaches the steam? Feedwater conditions directly affect that work.  He links inadequate feedwater heating with higher chemical demand,...

info_outline
498 Industrial Water Week 2026: Pretreatment Monday show art 498 Industrial Water Week 2026: Pretreatment Monday

Scaling UP! H2O

is here—and Day 1 is Pretreatment Monday. In Episode 498, Trace Blackmore, CWT, opens the 2026 celebration with troubleshooting stories, returning guest greetings, and a new Detective H2O case that brings pretreatment performance into focus. Celebrate with purpose Take a photo with your favorite pretreatment equipment—a softener, RO, or filter housing—and post it with #IWW26. Then search the hashtag to connect with others doing the same work. Trace’s invitation makes the week visible and recognizes the people who keep downstream systems operating. Start with the pretreatment train At...

info_outline
497 Pinks & Blues: From Sample to Solution show art 497 Pinks & Blues: From Sample to Solution

Scaling UP! H2O

 A controller and a handheld meter give you different readings. Before you adjust blowdown or chemical feed, how do you determine which result deserves your confidence? Reliable water treatment testing starts with understanding the sample, the system, and the equipment behind the number.  In Episode 497, “Pinks and Blues: From Sample to Solution,” Trace Blackmore, CWT, answers listener questions that build on Episodes 397 and 408. He connects testing with repeatable procedures so technicians can interpret results, make informed adjustments, and explain their decisions to...

info_outline
496 Growing Through Change in Water Treatment with Mark Lewis, Part 2 show art 496 Growing Through Change in Water Treatment with Mark Lewis, Part 2

Scaling UP! H2O

 When a water treater can run a test but cannot yet diagnose a failing system, the next training decision matters. In Growing Through Change with Mark Lewis, Part 2, Mark Lewis of CRB Water joins Trace Blackmore, CWT, to connect training choices with work in the field.   Match Training to Experience Mark sees the space between AWT’s March and November training sessions as a chance to revise material instead of repeating the same presentation. He explains how Fundamentals and Applications, Program Designs and Operations, and Technical Training serve different levels of readiness....

info_outline
495 Growing Through Change in Water Treatment with Mark Lewis, Part 1 show art 495 Growing Through Change in Water Treatment with Mark Lewis, Part 1

Scaling UP! H2O

Change is unavoidable, but uncertainty does not have to control how water treatment professionals respond to it. Mark Lewis returns to share what he learned when Southeastern Laboratories was acquired by CRB Water—and how employees can remain valuable, informed, and open to opportunity during a business transition.    Navigating an Acquisition from the Employee’s Perspective  Southeastern Laboratories began exploring a buyer because its owners wanted to protect the company and approximately 30 employees. When CRB Water entered the picture, employees naturally wondered what...

info_outline
494 Preparing for AWT 2026: Leadership, Change, and CWT Growth with Matt Coffindaffer, Part 2 show art 494 Preparing for AWT 2026: Leadership, Change, and CWT Growth with Matt Coffindaffer, Part 2

Scaling UP! H2O

A strong convention outcome starts before the first session and continues long after the exhibit hall closes. Association of Water Technologies Executive Director Matt Coffindaffer explains how deliberate preparation, wider professional relationships, and volunteer service can turn AWT 2026 into practical value for an industrial water treatment career or business.   Find the Right Place to Volunteer AWT offers yearlong committee service, shorter task-force assignments, and opportunities across technical research, marketing, membership, regulatory affairs, business resources, young...

info_outline
 
More Episodes

“Our goal is not zero Legionella pneumophila bacteria. Our goal is zero cases.” – Patsy Root 

Legionella risk becomes harder to manage when building teams treat every detection as equivalent—or collect samples without first deciding what a positive result will trigger. Patsy Root, Senior Manager of Government Affairs at IDEXX Water, explains how a clear water management program can replace uncertainty with defined responsibilities, routine monitoring, and proportionate action.  

 

Focus Testing on the Organism of Concern  

Patsy distinguishes between the broader group of Legionella species and Legionella pneumophila, the organism she recommends prioritizing during routine monitoring. She reviews research indicating that detecting non-pneumophila Legionella does not automatically mean L. pneumophila is present. 

That distinction matters operationally. Remediation can require significant time, money, facility disruption, and lost revenue. Testing targets and corrective actions should reflect public-health risk rather than a generalized fear of any Legionella detection. 

The goal is management, not eradication. A well-designed program aims to prevent disease while recognizing that completely eliminating the organism from every water system is not realistic. 

Define the Response Before Sampling 

Questions about routine monitoring remain among the most common Patsy receives: Where should samples be collected? How often should testing occur? Which laboratory and method should be used? What actions should follow a positive result? 

When reviewing a positive laboratory report, determine whether L. pneumophila was detected, its concentration, how many locations tested positive, and whether those locations are clustered or distributed throughout the building. Then compare the findings with the action limits and response procedures established in the water management program. 

Testing without a response plan can create unnecessary confusion. Likewise, writing a program does not protect a facility unless the assigned monitoring, flushing, temperature checks, chlorine residual measurements, documentation, and corrective actions are consistently completed. 

 

Connect Water Treatment, Exposure, and Ownership 

A conventional water treatment program designed for heat-transfer efficiency does not automatically address every public-health exposure route. Building teams must consider where people could encounter aerosolized or otherwise unsafe water—not only whether treatment chemistry is operating as intended. 

Patsy uses a milk-jug analogy to explain building ownership. Farmers, processors, transporters, and grocery stores maintain milk until it is purchased. Once the customer brings it home, however, that customer becomes responsible for storing it safely. Likewise, once water passes through the meter, the building owner becomes responsible for maintaining its quality. 

A comprehensive water management team may require a decision-maker with financial authority, a water treatment professional, plumbing expertise, maintenance and facilities personnel, and representatives from housekeeping, kitchens, or infection prevention where applicable. 

Communication with the public water system can also provide essential context about the incoming water source, seasonal temperature, distribution conditions, and disinfection. For water professionals advising building owners, the leadership challenge is translating risk information into repeatable actions that every responsible person understands and can sustain. 

Listen to the full conversation above. Explore related episodes below. Stay engaged, keep learning, and continue scaling up your knowledge! 

 

Timestamps 

02:00 — Trace Blackmore shares how Legionella Awareness Month began in 2020, why the topic continues to evolve, and why these episodes remain among the podcast’s most downloaded and shared. 

04:56 — Trace introduces returning guest Patsy Root, Senior Manager of Government Affairs at IDEXX Water, and revisits her appearances in Episodes 403 and 434. 

06:25 — Interview with Patsy Root about Legionella pneumophila testing, effective water management programs, professional education, and building-water responsibility. 

08:50 — Patsy explains why Legionella education remains necessary six years after the pandemic highlighted the risks associated with reopening stagnant building water systems. 

10:40 — Foundational Legionella education should be adapted to an audience’s experience, responsibilities, and understanding of microbiology. 

13:35 — AWT conferences and professional communities connect new practitioners with experienced professionals whose field knowledge may not appear in books or technical papers. 

16:10 — Patsy explains how professional collaboration helps the industry reassess long-standing assumptions about Legionella species and focus more precisely on L. pneumophila. 

20:20 — Patsy discusses how CWT and ASSE 12080 certifications are understood outside the water treatment industry and why credentials should be evaluated alongside experience, references, and work products. 

23:20 — Research from KWR, the World Health Organization, and the Journal of Hospital Infection challenges the use of non-pneumophila Legionella as an indicator for L. pneumophila. 

27:10 — Patsy distinguishes water management from eradication and explains why the objective should be zero disease cases rather than zero Legionella bacteria. 

29:40 — Legionella longbeachae is associated primarily with soil, potting mix, and compost, illustrating why professionals must consider the environmental context of published research. 

31:20 — Routine monitoring questions—where, when, how, and what to test—remain the questions Patsy receives most frequently from facility teams and water professionals. 

32:30 — Sustainable implementation depends on teaching everyone responsible for the program what to do and why each activity matters. 

34:30 — Patsy challenges the belief that avoiding Legionella testing eliminates risk and explains why routine verification remains necessary even when treatment measures are in place. 

37:10 — A conventional water treatment program may support heat-transfer efficiency without addressing every point where people could be exposed to unsafe water. 

38:40 — Patsy shares the milk-jug analogy to explain why a building owner becomes responsible for water quality after the water passes through the meter. 

42:00 — Patsy discusses the regulatory gap surrounding water inside many buildings and the need for persistent education, communication, and outreach to building owners. 

46:20 — Legionella requirements are beginning to appear in insurance policies as insurers and building owners recognize the financial consequences of outbreaks. 

48:40 — Accurate outbreak reporting should explain transmission, exposure routes, risk factors, and reliable sources of public-health information without creating unnecessary panic. 

51:20 — Patsy outlines how to interpret a positive laboratory result by reviewing the organism, concentration, number of positive locations, distribution, and established action limits. 

54:00 — Sampling should not begin until the facility knows how it will respond if Legionella is detected. 

55:30 — A cross-functional water management team should include financial authority, water treatment knowledge, plumbing expertise, facilities personnel, and representatives familiar with potential exposure areas. 

58:30 — Stronger collaboration between public water systems and building water management teams can clarify incoming water conditions and each party’s responsibilities. 

1:02:00 — Patsy answers four Legionella Awareness Month questions about management, trusted resources, common implementation failures, and the value of focusing on L. pneumophila. 

1:04:00 — Trace shares the episode discussion guide and the Scaling UP! H2O Legionella Resources Library for professionals reviewing the topic with their teams. 

1:07:00 — Words of Water with James McDonald  

 

Quotes

“It’s important to have everybody at the table, make sure everybody understands not only what they’re doing, but why they’re doing it.” 

“Don’t test the water for Legionella bacteria until you know what you’re going to do if it comes back positive.” 

“The housekeeping person’s not going to think like the plumber, and the plumber’s not going to think like the infection person, and the finance person’s going to think differently, too.” 

“Having a water management program does not absolve you from the daily or weekly activities that are required to be done. It must be done for it to be effective.” 

 

Connect with Patsy Root 

Phone: (207) 523-0835  

Email: [email protected]  

Website: IDEXX: Overview | LinkedIn  

LinkedIn: Patsy Root | LinkedIn  

 

Guest Resources Mentioned 

World Health Organization — Legionella and the Prevention of Legionellosis 

CDC Toolkit: Developing a Legionella Water Management Program 

ANSI/ASHRAE Standard 188-2021: Legionellosis—Risk Management for Building Water Systems 

KWR Publication: The Right to Effective Legionella Prevention—Section 7.4.4 begins on page 54 

Compulsory Screening for Legionella pneumophila and Legionella spp.—Journal of Hospital Infection 

Water Research Foundation: Occurrence of Legionella pneumophila in Drinking Water Distribution Systems 

The Analyst — AWT publication and archive for water treatment professionals 

Certified Water Technologist — CWT professional designation 

 

Scaling UP! H2O Resources Mentioned 

AWT (Association of Water Technologies) 

Scaling UP! H2O Academy video courses 

Submit a Show Idea 

The Rising Tide Mastermind

Scaling UP! H2O Legionella Resources Library 

403 Navigating the New Frontier: Patsy Root on Legionella Legislation 

434 Encore Interview with Patsy Root 

435 Optimizing Legionella Control Strategies with Dr. Vincenzo Romano Spica 

 

Words of Water with James McDonald 

Today's definition is the sodium salt of hypochlorous acid and is most commonly known as liquid bleach. 

 

2026 Events for Water Professionals 

Check out our Scaling UP! H2O Events Calendar where we’ve listed every event Water Treaters should be aware of by clicking HERE. 

 

This episode made possible through our valued partners at: