What is Aluminium?
Aluminium is found as a natural substance in water but can also be used in the treatment process in the form of Aluminium sulphate. This chemical however is removed during the water treatment process. Outside of the treatment process it is used in the construction, motor and aircraft industries as well as in cookware, soft-drink cans and tin foil. It is an indicator parameter for drinking water which means that it may indicate the presence of other parameters in a water sample. Aluminium occurs naturally in small amounts in both surface and ground waters (e.g. rivers or natural wells). In the Drinking Water Regulations, it is defined as a Indicator parameter.
What is an Aluminium exceedance?
A drinking water exceedance is a result from a drinking water sample which is above the acceptable limit. The limit for Aluminium in drinking water is 200µg/l, therefore any result that is greater than this is seen as an Aluminium exceedance.
What can cause an Aluminium exceedance?
Aluminium can be used in surface water treatment plants (usually in the form of aluminium sulphate) to remove impurities from raw water. Exceedances for aluminium can occur where small quantities of aluminium remain in the water following the treatment process.