Case Study: Bringing Cooling Tower Bacteria Under Control in One Week

Service: Cooling Tower Water Treatment
Location: Southwestern Ontario

Project Overview

A facility in Southwestern Ontario contacted WMC Water about excessive bacterial growth in its cooling tower. Testing had returned a bacteria count of 10,000,000 CFU, and algae was visible in the tower tray.

WMC Water reviewed the treatment setup with the client and found two issues: an insufficient biocide dosing program and a severely plugged injection line.

After correcting these issues and pressure washing the tower, bacteria counts dropped to below 10,000 CFU/mL within one week.

The Challenge

The existing treatment program was not keeping bacterial and algae growth under control.

The client needed to understand why the program was falling short and what changes would bring the system back under control. That meant checking both the biocide dose and the equipment delivering it.

The Game Plan

Step 1: Clear the Blocked Injector

WMC Water identified and cleaned a severely plugged biocide injector nozzle and line. This blockage was restricting chemical delivery and needed to be resolved for the treatment program to work properly.

Step 2: Correct the Biocide Program

WMC Water adjusted the biocide dose to an appropriate level for the system. The tower was also pressure washed to remove accumulated growth from the tray.

Together, these measures addressed the existing buildup and the problems that had allowed it to develop.

Step 3: Check Treatment Consistency

WMC Water followed up with the client daily to confirm that a measurable free chlorine residual was being maintained.

These checks provided a way to monitor treatment consistency while waiting for follow-up bacteria results.

The Outcome

One week after the changes and tower cleaning, testing showed bacteria levels below 10,000 CFU/mL.

The client also reported:

• Measurable free chlorine residuals each day
• A much cleaner tower tray that remained cleaner following treatment

The improvement followed a focused combination of equipment cleaning, corrected dosing, physical tower cleaning, and daily monitoring.

Why It Matters

When bacteria counts remain high despite an active treatment program, the dosing equipment deserves a close look.

In this case, the biocide program was insufficient, and a plugged injector was restricting delivery. Correcting both problems, alongside tower cleaning, produced a substantial improvement within one week.

Daily follow-up helped confirm that the revised program was maintaining a consistent residual, giving the client a clearer picture of how the treatment was performing.