5.13 Groundwater treatment
The treatment of groundwater frequently does not extend beyond disinfection. However, groundwater may contain dissolved substances such as carbon dioxide and iron for which additional treatment (aeration, biological treatment, etc.) may be required. In some instances groundwater may be hard, and where the concentration of dissolved solids is greater than about 300 g m−3 it may be desirable to soften the water to reduce scale formation and soap wastage. The methods usually adopted for softening are precipitation or ion exchange.