Point of Entry (POE) Legionella Water Treatment Strategy and Copper Silver Ionization:

Point of Entry (POE) water treatment applications treats all of the domestic cold water entering a facility. This strategy is not limited to the facility’s domestic hot water (DHW) areas. Commercial size copper-silver ionization technologies used in POE areas require additional alloy and electrical output power when compared to DHW types of applications. As a result, the necessary relative amperage for POE applications start at 30 amps (with 3 active ionization chamber cells) and goes as high as 160 amps (with 16 active ionization chamber cells) or more. The CSIDefender® ionization controllers adjust voltage automatically to provide the necessary set-point amperage (amperage = the amount of alloy ionized into the water), which in turn can be controlled by measuring water flow in real-time.

copper silver ionization chamber cells
copper silver ionization models

Moving forward with a POE type copper-silver ionization water treatment for your Legionella growth control or prevention is simple. Answer the following questions to size a commercial or medical grade copper-silver ionization solution:

• What is the size of the domestic POE cold water pipe?
• What is the total daily water usage for the facility?
• What is the maximum expected water flow?
• Are there any cold water storage tanks in the facility?
• Once you have all of your answers gathered, go to the CSIDefender® POE controller charts online or contact us, and we will provide you with recommendations.


DHW vs. POE is a judgment call based on evaluating the Legionella risk factors associated with your facility. For most North American facilities, a domestic hot water copper-silver ionization technology represents a reliable and affordable Legionella water treatment solution, which in turn, lowers exposure risks associated with Legionella bacteria, cause of Legionnaires Disease.

We hope that this document was helpful to you. Please contact us should you require guidance or additional information in this or any other Legionella water treatment strategies.