Why Legionella Water Testing Is Critical for Prevention

Legionnaire’s Disease remains a significant public health concern in the United States—especially in buildings with complex water systems. While anyone can contract the illness, it is far more dangerous for:

• Older adults, especially over 50

• Individuals with weakened immune systems

• People with chronic lung disease or smokers

• Those managing cancer, diabetes, or other significant illnesses

Early detection and proactive Legionella water testing play a critical role in protecting these vulnerable groups before outbreaks occur.

What Causes Legionnaires’ Disease?

Legionnaire’s Disease is caused by Legionella bacteria, most commonly Legionella pneumophila. These bacteria grow best in warm, stagnant water and spread when contaminated droplets or mist are inhaled—not by drinking water.

Typical environments where Legionella thrives include:

• Cooling towers and HVAC systems

• Hot water tanks and heaters

• Decorative fountains and water features

• Large plumbing systems

• Hot tubs, spas, and whirlpools

• Humidifiers and misters

Because the bacteria grow slowly and can hide in biofilms, contaminated water systems are often complex to disinfect without expert intervention.

Recognizing Symptoms

Legionnaire’s Disease can resemble severe pneumonia. Common symptoms include:

• Fever and chills

• Persistent cough — dry or mucus-producing

• Muscle aches and headaches

• Shortness of breath

• Loss of appetite and fatigue

• Confusion or trouble concentrating in severe cases

A milder flu-like form of the infection — Pontiac Fever — causes fever and muscle aches but does not lead to pneumonia. Both require medical attention when symptoms progress quickly.

How Serious Is Legionnaires’ Disease?

Many healthy individuals may fight off mild exposure with minimal symptoms. However, severe cases can lead to hospitalization, respiratory failure, or even death if not treated quickly with antibiotics.

U.S. health agencies continue to monitor substantial case numbers each year. Outbreaks are often traced back to commercial and public facilities with insufficient water management plans.

Prevention Starts with Legionella Testing

Since Legionella is easiest to control before it multiplies, proactive maintenance of building water systems is essential. Best practices include:

• Regular Legionella water testing and monitoring

• Preventing stagnant water in plumbing and cooling systems

• Maintaining hot water temperatures high enough to prevent bacterial growth

• Using approved biocides and disinfectants

• Removing scale, rust, and biofilm where bacteria hide

• Immediately addressing “dead legs” in plumbing where water sits unused

Hot tubs and spas require continuous disinfection and filtration because warm water creates ideal Legionella conditions.

Even newer facilities are not immune — energy-saving designs that reduce water temperatures, limit water flow, or infrequent usage can unintentionally increase the risk.

Responding to a Legionella Detection

If Legionella is found—or if an illness case is confirmed—the health department must be notified. Rapid action is required to:

1. Identify impacted locations

2. Sample and assess contamination levels

3. Treat and disinfect affected water systems

4. Implement corrective measures to prevent recurrence

These investigations are complex and should involve trained professionals such as industrial hygienists with experience in Legionella remediation and compliance.

Why Professional Testing Matters

Qualified environmental health and industrial hygiene specialists:

• Conduct certified sampling and laboratory analysis

• Develop or update a water management plan

• Identify risks in plumbing, HVAC, or water storage systems

• Assist with regulatory compliance and outbreak investigations

• Provide follow-up confirmation testing

Routine Legionella testing helps facilities avoid expensive shutdowns — and most importantly, prevent serious illness.

A Disease With Many Names — But One Cause

You may see the condition referred to as:

• Legionnaire’s Disease

• Legionellosis

• Legion Fever

• Pontiac Fever (milder form)

The disease was named following the 1976 outbreak at an American Legion convention in Philadelphia — a landmark case that led to the discovery of the bacteria.

Protect Your Facility — Protect Your People from Legionnaire’s Disease

If you are responsible for the safety of building water systems, proactive testing is your best defense.

For Legionella Water Testing, Sampling, and Prevention: Contact Phase Associates (formerly Atlantic Environmental).

Primary Service Areas Include:
NJ, NY, NYC, PA, CT, DE, MA (Boston), RI, Washington DC, WI, MD, MI, IL (Chicago), VA, IN, GA (Atlanta), AL, NC, SC, TN, TX (Dallas–Fort Worth), OK, AR
Additional U.S. locations may be serviced with travel accommodations.