Water Treatment

The quality of natural water continues to decline due to a number of factors, including denitrification, increased carbon dioxide in the soil and increased nitrogen and sulfur oxides in rain water. In order to raise the quality of natural water to a potable level (i.e. to a level acceptable for human consumption), we use different limestone grades to adjust the pH value (neutralization), to remineralize the water or to reduce the water hardness as defined by the TH value (total hardness) in all cases to reach the required calco-carbonic equilibrium. Controlling of this equilibrium is critical when managing any water and waste water treatment process.

Too little calcium carbonate yields water that is not saturated and may cause corrosion and deteriorate equipment and structures. A supersaturated solution will likely precipitate calcium carbonate, causing scale, reducing efficiency and eventually leading to system failure.


Calcium carbonate is an alkali with a typical pH value of 9, which makes it highly suitable for acid neutralization. Moreover, calcium carbonate is an appropriate source of calcium for the remineralization of desalinated water and increasing the hardness of natural soft water. Omya has over 40 years of experience in the water treatment market, mainly in pH control and soft water hardening. Omya’s pure granular calcium carbonate is specially adapted for use in the remineralization filter bed process.

Desalination is the process in which sea water or brackish water is distilled or passed through a series of reverse osmosis membranes to produce very pure water. The pure distillate or permeate water is very corrosive and must be remineralized to protect downstream pipelines/storage systems from corrosion and to meet the required standards for human consumption (drinking water).

Omya’s granular and micronized calcium carbonate products and technologies are key solutions in the remineralization of soft and desalinated water to reach the required water quality for drinking, irrigation or industrial use.

All our products comply with international drinking water standards such as European Standard EN 1018 and selected products are also certified by NSF-60 for use in drinking water treatment applications.


Mining depends on the Earth’s resources. Omya takes great care of the environment and re-naturalizes old mines and quarries.