Certified Facility Manager (CFM) Practice Exam

How is water typically 'softened' in a facility's water system?

1. By boiling it

2. By removing all minerals

3. By replacing hardness-causing minerals with sodium

4. By adding alkaline substances

The correct answer is: By replacing hardness-causing minerals with sodium

Water is typically 'softened' in a facility's water system through the process of ion exchange, where hardness-causing minerals, such as calcium and magnesium, are replaced with sodium ions. This method effectively reduces the concentration of compounds that create scale and buildup in pipes and fixtures, helping to prolong the lifespan of plumbing systems and improve the efficiency of water heaters and appliances. Using sodium ions instead of the naturally occurring hard minerals is advantageous because it prevents the issues associated with hard water, like mineral deposits that can impede water flow and damage equipment. In industrial and commercial settings, softening water can lead to significant cost savings in maintenance and operational efficiency. The other methods mentioned do not effectively achieve the desired results associated with water softening. Boiling water primarily removes dissolved gases and can lead to temporary softening if calcium carbonate precipitates, but it does not ensure a consistent reduction in hardness. Removing all minerals would not just eliminate hardness but also essential minerals, which can adversely affect water quality. Adding alkaline substances can alter the pH of water but does not soften it; instead, it may exacerbate scale formation under certain conditions. Thus, the most effective and widely used approach to softening water in a facility's water system is through the exchange of hardness