Legionella Testing for Arizona Healthcare Facilities

CMS Requirements: Why Hospitals Must Test for Legionella

The Centers for Medicare & Medicaid Services issued directive S&C 17-30-Hospitals in June 2017, requiring all acute care hospitals participating in Medicare and Medicaid to develop and maintain water management programs that reduce the risk of Legionella and other waterborne pathogens.

What CMS Requires

• Water management program: A documented, facility-specific plan following ASHRAE 188 guidelines
• Risk assessment: Identification of areas where Legionella could grow and spread (hot water systems, cooling towers, decorative fountains, ice machines)
• Environmental monitoring: Routine water sampling and Legionella culture testing at established frequencies
• Corrective actions: Documented response protocols when Legionella is detected above action levels
• Record keeping: Maintained logs of all testing results, temperatures, disinfectant levels, and corrective actions

Facilities Subject to CMS Legionella Requirements

ASHRAE 188 Water Management Plan Requirements

ASHRAE Standard 188 (Legionellosis: Risk Management for Building Water Systems) is the recognized framework that CMS, CDC, and accreditation bodies reference for Legionella prevention. A compliant water management plan includes:

1. Assemble a water management team with representatives from facility management, infection prevention, and environmental services
2. Describe the building water systems using flow diagrams that map all water sources, storage, distribution, and endpoints
3. Identify hazardous conditions where Legionella can amplify: stagnation, temperature fluctuations (77-113 degrees F danger zone), biofilm, scale, and sediment
4. Establish control measures including temperature management, disinfectant residual maintenance, and flushing protocols for low-use areas
5. Set monitoring schedules for temperature, disinfectant levels, and environmental Legionella culture testing
6. Define corrective actions for when monitoring results exceed action levels (typically 1 CFU/mL or any detection depending on facility risk)
7. Document and verify through ongoing record keeping and periodic program validation

What Is CDC ELITE Certification?

The CDC Environmental Legionella Isolation Techniques Evaluation (ELITE) program is a proficiency testing program that certifies laboratories capable of accurately isolating Legionella from environmental water samples.

AATLS is CDC ELITE certified, meaning every Legionella culture result from AATLS has been produced by a laboratory that has demonstrated proficiency to the CDC’s standards. This distinction is critical for healthcare facilities that need legally defensible, clinically reliable results.

Why Arizona’s Desert Climate Does Not Eliminate Legionella Risk

A common misconception is that Legionella is only a concern in humid climates. In fact, Legionella bacteria thrive in man-made water systems regardless of outdoor conditions. Arizona facilities face several specific risk factors:

Arizona-Specific Legionella Risk Factors

• Hot water system temperatures: Arizona’s high ambient temperatures can warm building water pipes into the Legionella growth range (77-113 degrees F / 25-45 degrees C), especially in poorly insulated or low-flow areas
• Evaporative cooling towers: Widely used across Arizona for building HVAC systems, these create ideal aerosol conditions for Legionella transmission
• Complex building plumbing: Large hospitals and resorts have extensive pipe networks with dead legs, low-use fixtures, and areas of stagnation where Legionella colonizes biofilm
• Seasonal occupancy fluctuations: Snowbird populations cause significant water demand swings in southern Arizona facilities, leading to stagnation during off-peak months
• Water features and fountains: Decorative fountains, misters, and splash pads common in Arizona commercial properties create aerosols that can harbor Legionella
• Construction and renovation: Arizona’s ongoing development means frequent water main disruptions and plumbing modifications that can introduce or disturb Legionella colonies

Legionella Sampling Protocols

Proper sampling technique is essential for reliable Legionella culture results. AATLS provides sampling guidance and supplies for healthcare facilities.

First-Draw vs. Post-Flush Sampling

Where to Sample

• Distal outlets: Faucets and showerheads in patient rooms, especially ICU, transplant, and oncology units
• Hot water system: Water heater outlet, recirculation return line, and mixed water at point-of-use
• Cold water system: Cold water taps at distal and proximal points
• Cooling towers: Basin water and make-up water supply
• Decorative fountains: Basin water if aerosol-producing features are present
• Low-use areas: Fixtures in infrequently occupied rooms or wings

Sample Collection Requirements

• Sterile containers with sodium thiosulfate to neutralize chlorine/chloramine
• Minimum 1 liter per sample (culture method requires adequate volume)
• Record water temperature at each sampling point
• Maintain chain of custody documentation
• Ship samples at ambient temperature within 24-48 hours of collection

Testing Frequency Recommendations

Additional testing triggers: Facilities should conduct immediate sampling after construction or renovation, water main breaks, changes to water treatment, any reported case of Legionnaires’ disease, or water system shutdowns exceeding 72 hours.

AATLS Legionella Testing Capabilities

• CDC ELITE Certified Proficiency-tested Legionella culture isolation
• ISO 17025 Accredited Full quality management system
• Culture-based analysis: Gold standard BCYE agar culture with species and serogroup identification
• Quantitative results: Reported as CFU/mL for direct comparison to action levels
• Serogroup identification: Legionella pneumophila serogroups 1-14 and non-pneumophila species
• Turnaround: 10-14 days for culture (organism growth requirement)
• Sample supplies: Sterile collection kits shipped to your facility
• Compliance reporting: Results formatted for CMS surveys, Joint Commission accreditation, and state health department requirements

About the Laboratory Director

AATLS was founded by Dr. Glenn Cherry, an Air Force veteran and Doctor of Veterinary Medicine. Dr. Cherry’s background in both military service and clinical microbiology provides AATLS with a rigorous, quality-driven approach to Legionella analysis that healthcare facilities can rely on for compliance and patient safety.