Milk produced under good control should not show any trace of added water.  If added water is detected, the amount of water added is calculated based on the volume recorded at that collection and the test result, this volume is then penalised at the payment rate applying in that month.  If on a second occasion the supplier is found to have added water the milk supplied in the week of the second offence and the average of the amounts of added water is used to calculate the volume to be penalised.

If there is a third offence in a month, the average of the test and the total delivery for the month is used to calculate the amount of water added.