A water treatment apparatus management system which manages a household water treatment apparatus located at or near a place of water use, and treats water before treatment with at least one type of filter to produce treated water for the place of water use. The system includes: a filter information storage unit storing information regarding an in-service filter used in the household water treatment apparatus; an information receiver receiving information regarding performance change of the in-service filter from the household water treatment apparatus; and a water type estimation means that estimates a water type of the water before treatment based on the information regarding performance change and the information regarding the in-service filter. The information regarding the in-service filter includes reference information of performance change of the same or the same type of filter as the in-service filter for each of plural types of reference water before treatment.