Below are some guidelines for detecting microbiological organisms in cooling water systems and will help shed some light on what may be the cause:
- Read daily log reports on cooling system operation. Compare average daily operating data and note any abnormal variations.
- Read the service reports filled out by your water treatment supplier to determine any significant trends.
- Question operating personnel about changes in process or treatment programs, equipment changes or changes in personnel who may be unfamiliar with the water treatment program. Also, take into account climatic changes which affect water temperature.
The easiest place to gain access to cooling water is at the sump or tower basin. Although it is not representative of the entire system, it can often provide useful information in a relatively short period of time.
- Feel the wetted supports and basin walls to determine the presence of slime.
- Visually examine upper distribution area and sump for slimy masses.
- Take a water sample and note the color and odor of the sample.
- Take a simple Total Plate Count test or Microbiological “dip slide”. These inexpensive tests will enable you to make a population count of bacterial colonies as well as mold and fungus. The results should be compared to previous tests and system performance to determine whether a problem condition exists. If slimy masses are noted, they should be examined microscopically to determine if they are biological in nature.
In addition, here are a few more procedures to follow to detect the presence of microorganisms in your Cooling Water system:
- Climb around the tower and inspect the condition of wood fill and supports. Use an ice pick to probe for soft spots. Check for lime, fungi, dirt, leaves and other debris.
- Keep written records of inspections and tests for future reference.
- In special cases, an untrained observer may not detect evidence of biological activity when the problem exists. Therefore, it is a good policy to call a field engineer for an in-depth inspection of the system. Remember, they have inspected many different cooling systems and have specialized knowledge on how to keep them operationally reliable.