Controlling Legionella in Medical Building Cooling Towers

Executive Summary

• Cooling towers naturally foster Legionella bacteria. The standard treatment method, a biocide program, relies on standard chemical feed pumps that can have feed rate issues or mechanical failure.”
• ProChemTech’s proprietary Aqua Ionic technology uses softened makeup water to enable high-cycle operation, reduce blowdown discharge, and passively prevent the growth of legionella in a cooling water system.
• Healthcare facilities must prioritize evidence-based water management strategies that satisfy strict regulatory standards while protecting expensive HVAC infrastructure from corrosion.

Protecting Vulnerable Patients From Waterborne Pathogens

Hospital and medical facility managers must constantly monitor their cooling towers to prevent Legionella outbreaks. This pathogen poses a serious threat to patients, staff, and visitors throughout the building. Keeping water systems safe and compliant is a difficult daily task.

ProChemTech offers a proprietary water chemistry solution that naturally inhibits bacterial growth. We help facilities reduce risk and save water through advanced engineering. Read on to learn more about our high-cycle technology and how it can control Legionella in hospitals and other medical building cooling tower systems.

Get a Quote for Controlling Legionella in Cooling Towers

Why Are Medical Building Cooling Towers Prime Breeding Grounds for Legionella?

Cooling towers provide warm temperatures, nutrients, and aerosol dispersion that support Legionella multiplication. This combination increases infection risks for vulnerable patients and staff.

How Cooling Towers Actually Spread Bacteria

Several conditions make medical building water cooling towers the primary source of healthcare facility outbreaks:

• Ideal Breeding Grounds: Cooling towers operate at 68°F to 122°F, the ideal temperature range for Legionella pneumophila growth. These systems function like massive lungs, inhaling air and water while exhaling potentially contaminated drift.
• The “Treatment Gap”: Relying on mechanical pumps introduces risks, as a single failure leaves the system unprotected. Traditional biocide programs depend on “active” killing mechanisms that inject chemicals on a timer.
• Aerosol Transmission: Drift generated by evaporation can carry bacteria into air intakes if the water is contaminated. Inhalation of these aerosols remains the primary vector for Legionnaires’ disease.

Avoiding Financial Penalties and Operational Shutdowns

Medical facilities carry serious liability exposure when Legionella outbreaks trigger regulatory penalties from CMS or the Joint Commission. Water treatment systems must maintain constant uptime to protect vulnerable patient lives.

How Does ProChemTech Help Control Legionella in Medical Facility Cooling Towers?

At ProChemTech, we solve the root cause of Legionella risk with our patented Aqua Ionic technology. Our system softens makeup water and enables high-cycle operation at elevated pH levels. This biostatic environment suppresses Legionella without relying on mechanical systems alone.

The system delivers this through three mechanisms:

Removing Hardness to Enable High-Cycle Operation: Pre-treating makeup water removes calcium hardness and eliminates the primary cause of scale formation. Scale reduces heat transfer efficiency and feeds bacterial biofilm. Our softening process allows water to concentrate 8 to 10 times without fouling heat exchangers or piping.

Creating Water Chemistry That Bacteria Can’t Survive: Concentrating water to 8 or 10 cycles drives pH levels between 9.3 and 10.0 with high alkalinity. These conditions prevent Legionella from reproducing. We do not just add chemicals to kill bacteria. Instead, we alter the water environment itself to make bacterial growth impossible.

Protection Even When Mechanical Systems Fail: The water chemistry acts as a passive barrier during mechanical interruptions. High pH and alkalinity remain hostile to pathogens even when biocide pumps fail. The system protects itself through water physics rather than mechanical injection alone.

Why Passive Safety is Better Than Chemical Pumps

Shifting from reactive chemical dosing to proactive environmental control helps ensure continuous compliance with healthcare safety standards. Chemical pumps can experience mechanical failure, which leads to dosing errors that have wide-reaching consequences throughout the treatment system.

Preventing Corrosion While Controlling Pathogens

Most facilities sacrifice either pathogen control or equipment longevity when treating cooling towers. ProChemTech’s system protects both simultaneously through coordinated chemistry and monitoring:

• Solving “White Rust”: Soft water can be aggressive toward galvanized steel and potentially cause “White Rust” (zinc corrosion) if left untreated. Protecting galvanized components in this environment requires inhibitors designed specifically for high-pH, soft-water chemistry.
• The GalvaGard Solution: Applying specific inhibitors like GalvaGard coats and protects metal surfaces in high-pH, soft-water environments. ProChemTech developed this formulation to allow medical facilities to use Aqua Ionic technology without sacrificing HVAC equipment longevity.
• Holistic Water Management: Managing the entire water profile involves integrating automatic side-stream filtration to remove solids and monitoring conductivity in real-time. We employ remote monitoring systems to track pH continuously, ensuring the chemical balance remains correct.

Avoiding Dual Regulatory and Mechanical Shutdowns

Legionella outbreak triggers immediate regulatory shutdown while corroded equipment forces extended closure for replacement. Facilities that fail at either pathogen control or corrosion prevention face compounding downtime that disrupts patient care for months.

What Is the Scientific Basis for High-pH Legionella Control?

Research indicates that maintaining hospital cooling tower water at a pH above 9.2 creates a biostatic environment where Legionella bacteria survival is minimal.

Validating Safety with Peer-Reviewed Microbiology

We rely on proven science instead of marketing fluff to keep your water safe.

The “States et al.” Study: Research by States et al. (1987) proved that pH and alkalinity inversely correlate with Legionella growth. It cannot tolerate pH levels above 9.2. Operating cooling towers above this threshold stops bacterial multiplication.

ATP Verification: ATP testing measures total biological activity in cooling water. High-cycle, high-pH towers consistently show lower ATP levels than standard biocide-treated systems. We use ATP data with pH monitoring to verify system safety.

Field Proven Results: We tested 17 cooling towers using Aqua Ionic technology (some operated without any supplemental biocide). Every test returned “none detected” for Legionella. The high-pH environment functions as a biostat without toxic chemical dependence.

Meeting Evidence Requirements for Compliance and Liability Protection

Regulatory auditors and insurance carriers require documented evidence that water treatment methods effectively control Legionella. Peer-reviewed microbiology research and ATP field data provide the validation needed to satisfy compliance requirements and defend treatment decisions during outbreak investigations.

Additional Questions / FAQ

Q: Does running at high pH violate ASHRAE 188 standards?

A: No. ASHRAE 188 requires a water management program that controls Legionella, and using high-pH chemistry is a validated control measure within such a program.

Q: How much water can a hospital expect to save?

A: Moving from standard 3 cycles to 8+ cycles of concentration typically reduces cooling tower blowdown discharge by 90% to 98%.

Q: Is the Aqua Ionic chemistry compatible with existing cooling towers?

A: Yes. The cooling tower treatment chemistry adapts easily to existing cooling tower systems and helps treat hard alkaline makeup water.

Let ProChemTech Help Protect Your Patients and Hospital From Legionella

Controlling Legionella in cooling towers requires a reliable strategy that goes beyond standard chemical treatments. Medical facilities need a system that prevents bacterial growth through fundamental water chemistry changes.

At ProChemTech, we provide a scientifically proven system that protects building occupants and extends equipment life. Our team works directly with hospital engineers to implement safe and sustainable water management programs.

Click below for a quote and to learn more about securing your cooling systems today.

Get a Quote for Controlling Legionella in Cooling Towers

References / Sources

States, S. J., Conley, L. F., Kuchta, J. M., Oleck, B. M., Lipovich, M. J., Wolford, R. S., Wadowsky, R. M., McNamara, A. M., & Sykora, J. L. (1987). An alkaline approach to treating cooling towers for control of Legionella pneumophila. Applied and Environmental Microbiology, 53(8), 1775–1779. https://pubmed.ncbi.nlm.nih.gov/3662515/