Copper-Silver Ionization Water Treatment, a recognized Legionella growth control and prevention water treatment technology, is commonly installed in more extensive facilities with elaborate potable water distribution networks.
These larger facilities typically have higher daily potable water usage when compared to residential facilities. Such buildings include healthcare facilities, long-term care, schools, high-rise buildings, hotels, and cruise ships.
Copper-Silver Ionization water treatment technology electrically generates and then dispersing measurable ionic Copper (Cu2+) and Silver (Ag+) into a facility’s potable water distribution network. The ionic dispersion objectives include the saturation of the main water lines and the distal areas where Legionella issues typically arise.
Copper-silver ionization is scientifically proven to prevent Legionella growth in facility potable water distribution networks. Most peer-review studies support the use of CSI technology for Legionella growth control.
However, some negative outcome studies (2 or 3) have shown challenges due to defective or inappropriate smaller swimming pool-type CSI units. These smaller units are not engineered for potable water applications. These particular “negative” studies mislead the reader and can lead them to dismiss CSI technologies without fully understanding the flawed experimental methodology.
In most cases, these “negative” CSI studies do not use CSI technologies that can maintain a minimum ionic value required for continual Legionella growth control or remediation.
The fact remains that commercial or medical Copper silver ionization has been used in more extensive facilities for legionella control or remediation for well over 20 years.
The technology is recognized by numerous health and regional authorities around the world. CSI technology is also recognized by the WHO, EPA, and CDC to control the growth or remediate Legionella bacteria in elaborate potable water distribution networks.
Since copper-silver ionization is known to penetrate biofilm to stop Legionella growth, where it is usually protected and grows, the technology application is classified as “systemic Legionella growth control or remediation.”
When activated, the injected copper and silver ions should be monitored and maintained below the maximum allowed potable water standards for human consumption.
These values can vary for different countries, yet the maximum allowed elemental CuAg values globally are: Cu (1.00 ppm) and Ag (0.10 ppm). However, the maximum allowed Cu value for potable water in the USA is 1.30 ppm.
The minimum required generated copper-silver ionization values for Legionella growth control are 60% less than the maximum globally allowed elemental values. These values are measurable via the use of third-party water testing equipment.
The Engineering of Copper-Silver Technology:
CSI technology applications are typically composed of two key components. The first is a sophisticated, fully automated electronic controller. The other is (are) the ionization chamber cell(s) that contain the copper and silver electrodes (or copper-silver alloy electrodes).
Both elemental or alloy electrodes can be used for Legionella growth control or remediation as long as the commercial or medical electronic controller is engineered for such different types of applications. (smaller swimming pool type controllers are not engineered for facility potable water applications).
The electrical output power capacity and the number of installed ionization chamber cells (or available elemental copper/silver) are always proportional to daily water usage and maximum water flows.
A general industry rule requires up to 10 amps power and one ionization chamber cell (10kg) for each 100M3 of daily water usage to last 9 – 14 months based on water conditions (Ex: water hardness). As expected, the elemental copper and silver will deplete over time, and new electrodes will be required to replenish the depleted ones.
However, point of use vs. domestic hot water applications must be factored into properly sizing an appropriate copper-silver ionization solution. Consultant engineers or facility management personnel should always consult a CSI expert before installing potable water treatment technology to not undersize the application.
Under-sizing a CSI technology always leads to application challenges either by never attaining the minimum required ionic values or depleting the chamber cells prematurely adding to the overall operational cost and over-stressing the smaller controller.
Once a copper-silver ionization application is sized correctly, the appropriate number of chamber cells are installed (paralleled to each other) in the water distribution network along with the electronic controller capable of delivering the power capacity requirements.
The installation location of the ionization chamber cells can either be at the facility point of entry (POE) to treat 100% of the incoming potable water or the domestic hot water (DHW) location only. However, a CSI professional or Legionella expert needs to determine the final installation location based on a facility’s relative Legionella risk assessment.
Once installed, the fully automated CSI electronic controller is interlinked to the ionization chamber cell(s) via electrical wires. Water will then flow within the chamber cells; the controller will be activated and calibrated based on actual water usage.
A CSI controller’s internal power capacity can vary based on the manufacturer, yet only CSIDefender® is known to deliver 20 amps capacity or higher with a single, more powerful controller.
This translates to a smaller relative technology footprint when compared to less sophisticated CSI units along with a more affordable start-up cost. In fact, CSIDefender® is the only brand capable of delivering 20 to 160 amps of capacity with a single industrial PLC.
It should be noted that sophisticated medical and commercial copper-silver ionization potable water treatment technologies, such as CSIDefender®, include unique engineering automation and monitoring features required for Legionella growth control and prevention.
These are key in a successful Legionella prevention program when secondary potable water treatment is required. Those lacking these commercial/medical engineering features have been reported to fail or break down within a few weeks of activation.
Some copper-silver ionization technology applications, such as the CSIDefender® FM series, use flow meters for inline activation control. These are regularly used in point of entry applications to treat 100% of a facility’s potable water.
However, older, less sophisticated CSI units have been known to use flow meters as a means to compensate makeup water linked to the domestic hot water loop. (Not required with CSIDefender®) This older CSI-DHW technique, known as DHW proportional control, has been reported to be unreliable over time and is not recommended unless additional water parameters are monitored.
Finally, consultant engineers and users must recognize that smaller swimming pool-type copper-silver ionization units, seemingly more affordable than commercial or medical ones, are not engineered for facility potable water applications.
These smaller swimming pool copper-silver ionization units, generally sold for between $2,000 (USD) and $10,000 (USD), have been reported to fail and cause Legionella public health risks. They are engineered for residential and some commercial swimming pools. They must not be used for larger facility potable water applications.
The continual daily water loads exceed the technology capacity after only a few days or weeks of operations. Only commercial or medical copper-silver ionization technology should be used for facility potable water Legionella control treatment applications.
These more sophisticated and higher capacity CSI units, engineered to deliver Legionella prevention results, cost between $15,000 (USD) and $95,000 (USD) based on the size, type of application, and features.