The Water and Sewerage Authority currently uses aluminum sulfate granules supplied by Kemira Chemicals at its Skullerud plant. The treatment plant has been designed to use the chemical, which has been proven to be successful. The product shall remain listed in the NFSA's list of approved chemicals for treatment of potable water, according to § 15 of the Directive on Water Supply and Drinking Water.
There are other vendors that supply aluminum sulphate. Prior to any switch to a new product, both laboratory and full-scale tests of the products are required to ensure that it provides the same result and quality. Other products could also result in modifications in the plant.
In the event that there are additional vendors who want to offer aluminum sulfate granules and sufficient testing has been conducted permitting usage at the plant, application can be made to the Norwegian FSA for approved entry on the list.