Cooling towers play a critical role in keeping commercial, institutional, and industrial facilities running efficiently. But without a thoughtful water treatment system, these same cooling towers can quietly become one of the biggest threats to system performance and sustainability. Scaling, corrosion, biological growth, and water waste can all take a toll – shortening equipment life and driving up operational costs across the cooling tower system.

At EAI, we work with facility teams across the U.S. to design cooling tower water treatment programs that are engineered for the real-world conditions experienced on site. With over three decades of field and tower water treatment chemistry expertise, we help clients reduce risk, save water, and meet environmental standards. In this guide, we’ll break down the core components of an effective treatment plan for your system.

Why You Need a Cooling Tower Water Plan

A well-developed water treatment process plan for cooling tower systems is a proactive strategy to:

• Prevent scale buildup and corrosion in heat exchange surfaces
• Control biological activity (like algae, bacteria, and Legionella)
• Reduce blowdown water waste and chemical usage
• Maintain energy efficiency and extend equipment life
• Stay in compliance with local environmental and health codes

Without treatment, cooling tower water can become chemically imbalanced, damaging both system infrastructure and public health.

Step 1: Understand Your Cooling Tower System

Every plan starts with a detailed understanding of how your cooling tower operates – because no two systems are exactly alike. This includes reviewing the physical layout, equipment configuration, and operational demands that impact water quality and system stress in the cooling tower.

Key considerations include:

• System size and tonnage – Larger cooling tower systems have greater water volume, flow rates, and heat load, which influence treatment dosage and monitoring frequency.
• Circulation rates and operating hours – Continuous vs. intermittent use impacts microbial risk and scaling potential. Longer runtimes demand more robust treatment oversight.
• Makeup water source and quality – Whether sourced from city water, well water, or reclaimed water, each brings a unique chemical fingerprint (e.g., hardness, silica, chlorides) that affects how cooling tower water treatment must be performed.
• Cycles of concentration (COC) – The higher your cycles, the more efficient your cooling tower – but also the more precise your water treatment control must be to avoid scaling or corrosion.
• Heat exchanger types and metallurgy – Copper, stainless steel, and mild steel all respond differently to corrosion and treatment chemicals. Knowing the materials helps inform chemical compatibility and dosing limits.
• Facility-specific challenges – Outdoor cooling towers may deal with airborne debris or biological contamination; data centers may require ultra-tight temperature stability; seasonal facilities need protection during layup periods.

Our first step with any client is conducting a full site evaluation to document conditions, analyze risks, and uncover hidden vulnerabilities that may not appear in standard operating data. This ensures every plan we build is grounded in actual cooling tower operations, not just theory.

Step 2: Analyze Your Water Chemistry

Makeup water composition is one of the most important factors in cooling tower water treatment planning. Key parameters include:

• Total Dissolved Solids (TDS)
• pH and alkalinity
• Hardness (calcium and magnesium)
• Chlorides and sulfates
• Silica
• Conductivity
• Microbiological activity (bacteria, fungi, algae)

These values help determine scaling potential, corrosion risk, and microbial vulnerability. EAI uses high-precision lab and field testing to inform treatment decisions and track cooling tower water treatment trends over time.

Step 3: Set Performance Goals

With system specs and water chemistry in hand, the next step is setting achievable goals for your cooling tower water treatment agenda. Common objectives include:

• Maintain 3–6 cycles of concentration (COC)
• Prevent scale at high heat-load areas (above 130°F surfaces)
• Keep corrosion rates below industry benchmarks (e.g., <2 mils per year for mild steel)
• Maintain low Legionella risk per ASHRAE 188 standards
• Optimize cooling tower water treatment chemical use for maintenance cost-efficiency and sustainability

These goals guide treatment selection, monitoring frequency, and control strategy for the cooling towers and your facility teams.

Step 4: Select and Apply Effective Cooling Tower Treatment Methods

A robust treatment plan includes both chemical and non-chemical strategies. Based on your water profile and system needs, EAI may recommend a combination of the following:

1. Treating Makeup Water
   Makeup water replenishes losses due to evaporation and leaks in a cooling system. Treating makeup water can involve removing hardness, adjusting pH levels, and using water softeners to prevent scale formation. This step reduces the chemical burden downstream and supports longer system life.
2. Filtration
   Filtration removes suspended solids and organic matter that contribute to fouling, scaling, and corrosion. Options include multimedia filters, cartridge filters, or self-cleaning strainers—each selected based on flow rate, debris load, and space constraints.
3. Chemical Treatment
   Chemicals help maintain water quality and prevent issues such as scale, corrosion, and microbial growth. Common cooling tower treatment chemicals include:

• Scale and corrosion inhibitors – Protect metal surfaces and reduce mineral buildup
• Biocides and algaecides – Control microbiological growth and biofilm formation
• pH adjusters – Maintain optimal water balance for treatment efficacy
• Anti-foaming agents – Prevent foam formation that can reduce cooling system efficiency

4. Side-Stream Filtration
   Side-stream filtration continuously filters a small percentage of circulating water to remove suspended solids and contamination from air drift, leaks, or organics. This improves overall water quality, reduces fouling, and enhances chemical performance.

Real-World Example: San Jose Convention Center

Cooling tower water reuse is already delivering major results for public and commercial buildings. At the San Jose McEnery Convention Center, EAI engineered a high-efficiency cooling tower treatment program in alignment with the city’s Green Vision and Climate Smart goals.

With a 2,500-ton cooling system consuming millions of gallons annually, EAI implemented a reverse osmosis (RO) solution to reclaim over 50% of cooling tower blowdown water. The optimized cooling tower chemical program increased cycles of concentration and significantly reduced fresh water demand, saving over 3 million gallons annually while protecting performance.

Step 5: Implement Monitoring and Testing Protocols

To be effective long term, a treatment plan must be actively monitored—not just occasionally checked. Real-time oversight helps facilities avoid chemical overdosing, respond to changing conditions, and prevent small issues from escalating into costly failures.

Best practices include:

• Daily operator log checks – Record conductivity, pH, and temperature to establish system baselines and detect early warning signs.
• Weekly test kits or onsite monitoring – Evaluate chlorine/bromine levels, hardness, and other quick-turn parameters to ensure proper chemical residuals.
• Monthly or quarterly lab testing – Conduct comprehensive analysis for metals, bacterial counts, inhibitors, and other trends not captured by handheld tests.
• Automation via smart controllers – Use real-time sensors and programmable logic to adjust chemical feed and alert operators to drift or anomalies.

One common solution we’ve applied to support facilities is through integrated digital monitoring platforms, remote alert capabilities, and detailed service reports. Our goal is to simplify oversight, reduce guesswork, and ensure that your treatment plan continues to deliver reliable performance every day.

Step 6: Document and Maintain Records

Documentation ensures regulatory compliance, system accountability, and treatment transparency. Your water treatment process records should include:

• Detailed site schematic and flow diagrams
• Water test records (manual and automatic logs)
• SDS sheets and chemical handling protocols
• Legionella risk management procedures
• Service reports and corrective actions

This documentation also protects your water treatment team in the event of a regulatory audit or unexpected equipment failure.

Step 7: Review, Adjust, and Optimize

Cooling tower water chemistry isn’t static, it changes with seasons, source water shifts, and operational changes. EAI recommends reviewing your cooling tower treatment plan:

• Quarterly, to verify goals are being met
• After system changes (new chiller, makeup source, chemical swap)
• Annually, to update protocols, optimize chemical use, and renew documentation

Our cooling tower water treatment specialists help clients recalibrate as needed, applying real-world data to reduce operating costs and improve treatment reliability.

Why EAI?

EAI combines expert-level water treatment knowledge with Legionella control, facility operator support and water efficiency. We don’t just maintain cooling tower systems, we deliver complete solutions straight from our advanced water treatment offices to your facility.

Whether you’re managing a data center in Nevada, a university in California, or a medical center in Arizona, EAI helps you develop and execute a reliable plan that:

• Prevents downtime
• Reduces water and energy use in your cooling tower
• Meets environmental standards
• Protects your infrastructure long term

Let’s Build Your Cooling Tower Water Plan

If you’re operating a cooling tower and don’t yet have a complete treatment plan or your current program isn’t hitting performance targets, EAI is ready to help.

We offer cooling tower site assessments, water chemistry testing, system mapping, and plan development facility-specific approach to your equipment and regional water conditions.

Contact EAI today to schedule a consultation or system review.