490 From Plans to Prevention: Water Management Insights with Dr. Abe Cullom

A water management plan protects people only when the facility uses it to guide decisions. Dr. Abe Cullom, Director of Water Safety & Management at Pace Analytical, joins Trace Blackmore, CWT, to examine why Legionella programs break down—and how testing, communication, and consistent implementation can strengthen them.

Implementation Is the Bottleneck

Five decades after Legionella was identified, researchers understand much more about the organism, its ecology, the conditions that support its growth, and the interventions available to control it. However, Dr. Cullom identifies implementation—not a lack of science—as the primary bottleneck.

Many plans remain in filing cabinets or operate on autopilot. Teams collect measurements and samples, yet no one connects the results into a complete picture of the building water system. Process failures, limited follow-up, budget constraints, and unclear communication can allow a developing problem to remain hidden behind repeated low-level corrective actions.

Testing Must Inform Risk

Culture remains a dominant testing method, although the typical wait for results can complicate decisions during an investigation or operational change. qPCR provides faster results but may detect genetic material from both living and dead cells. Dr. Cullom also explains viable but non-culturable cells and why recent heat treatment, supplemental disinfection, oxidative stress, or prolonged stagnation can affect culture results.

The goal is not automatically to drive every Legionella result to zero. Instead, teams should interpret findings using the species detected, distal site positivity, the facility's population, and the limitations of the testing method. Dr. Cullom explains why testing only for Legionella pneumophila may make sense in some systems, while healthcare facilities may require a broader view because highly immunocompromised patients can develop infections from other Legionella species.

Ownership, Communication, and Continuous Review

Water management plans often fail when responsibility for corrective action has not been assigned. Dr. Cullom calls one version of this breakdown the "milkman approach": a consultant or water treater delivers results, but the facility expects that outside party to organize a response that was never included in the scope.

Effective programs clearly define authority, assign actions, and give engineers, infection prevention professionals, facility leaders, consultants, and water treaters a shared vocabulary. When reviewing a program, examine its records, verification and validation activities, corrective-action documentation, and long-term data trends.

Dr. Cullom recommends giving someone at least 30 minutes each month to consider what the results reveal and whether the plan needs to change. He closes with a direct priority: validate every plan through testing—at least once and, ideally, routinely.

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