All water is not created equal. While, yes, the prerequisite two-parts hydrogen, one-part oxygen defines water in all of its forms, in practice every drop will be defined by the infinitely diverse combination of impurities and contaminants that come with it.

Some water may be salty, and that’s fine for some thermoelectric power generation. Water that has been treated for human consumption may still retain benign, microscopic impurities. But only that which has been treated to the strictest possible standards can be considered ultrapure water.

In some operations such as pharmaceutical production, laboratory research, and supercritical boiler power generation need high purity water. These operations are so precise that if any of contaminants that would interfere.

The highly pure water process begins with pretreatment, typically through a slandered reverse osmosis water filter (RO) as first pass, UV purification, before employing a deionizing water system of second pass reverse osmosis water filter (RO) or ion exchange or electrodionization (EDI). Ultrapure water is created through varying riffs on this formula and the exact quality standards of the final product differ depending on what it will be used for.