A risk assessment involves looking at the source of the supply, water catchment, water intake, storage, treatment and distribution of a supply to estimate if there is a significant risk of contamination and supplying water that may not be safe to drink.

Risk assessments help identify problems and encourage the use of risk-management during treatment and distribution so that sampling is not relied on as the only way to identify potential health risks. The assessment identifies actions that need to be taken to control the risks.

Risk assessments can only be performed by the local authority or by people we have deemed competent.  The frequency that a risk assessment must be carried out on your supply is determined by the supply's classification and result of the initial risk assessment.