This type of problem normally occurs on borehole supplies and is a clear indicator that the water contains high levels of iron or manganese. The water entering the house may look perfectly clear, however, once air is introduced into the water e.g. through agitation in a washing machine or dishwasher, the iron precipitates and leaves behind an orange or brown stain. Iron can be particularly problematic on farms where the sanitization fluids used to clean equipment cause the iron to precipitate, leaving unsightly stains on what is otherwise sterile equipment.