Corrosion Control in Municipal Water Systems
Drinking water suppliers in many parts of the United States and Canada have difficulty in meeting EPA standards for allowable traces of lead and copper in potable water. In addition, a given municipality’s method of corrosion control can significantly impact overall operational costs over and above those in place for metals control.
Bicarbonate alkalinity exists naturally in most water supplies. Waters deficient in this parameter due acid rain or other causes are often corrosive. Supplementing waters with sodium bicarbonate to restore the alkalinity level between 30 and 40 mg/L as CaCO3 (and an optimum pH between 7.5 and 8.5) reduces the corrosiveness of the water and creates a thin, tenacious, carbonate coating on the interior of lead and copper pipes. This coating seals water out of the interior surface of the pipes, and reduces metal leaching.
Other Potable Water Process Considerations
In addition to metals and corrosion control, sodium bicarbonate can improve the performance of other water treatment chemicals. Proper bicarbonate alkalinity is required to optimize other water processes, including chlorination, flocculation and coagulation – and it can lead to significant savings.
Unlike phosphates, sodium bicarbonate does not promote biofilm growth.