AquaPure® Phosphates

Phosphates have been used for over sixty years to improve drinking water quality. Originally, they were added to well water to sequester iron, manganese and other naturally occurring minerals. In the early 90s, the Lead and Copper Rule provided a new avenue for phosphate use: the reduction of lead and copper through corrosion inhibition.

There are two types of phosphates: Orthophosphates and Polyphosphates. Orthophosphates are single phosphates, which combine with calcium in water, creating a calcium orthophosphate barrier film. The barrier film forms between the distribution system’s pipes and the drinking water. This protects the metal from corroding, delivering clean, iron-free water to the customer. Polyphosphates, in contrast, consist of many phosphates linked together in a long chain of sodium or potassium ions.

Polyphosphates sequester naturally occurring minerals in the water, such as iron, manganese and calcium. The polyphosphate ties up, or sequesters the mineral. In this way, the mineral remains in a clear, soluble state, instead of reacting with chlorine through oxidation and causing red or black water.