- Single Private Dwellings: Single private dwellings will not require routine monitoring or a risk assessment, unless they are rented to a third party in which case they will be classified as commercial premises. Sampling and/or risk assessment can be undertaken at the owner's request.
- Small Domestic Supplies: The frequency of monitoring will depend on the outcome of the risk assessment. However, it will be a minimum of once every five years. Supplies will be monitored for five basic parameters and anything else that arises from the risk assessment.
- Private Distribution Systems: Monitoring must be carried out according to the outcome of the risk assessment, and at least once every five years.
Large Supplies or Commercial Premises: Two types of monitoring will occur on these supplies:
- 'Group A' monitoring tests the wholesomeness of the water; the frequency of monitoring Group A parameters will depend on the amount of water used.
- 'Group B' monitoring determines whether or not the water supply meets the required legal standards. The range of Group B parameters which may be monitored is extensive and the frequency of monitoring depends on the amount of water used.
All large or commercial supplies will have at least one sample analysed each year.