[The quantitative classification and survey of sanitation of urban secondary water supply in Haidian district of Beijing].

Objective: To investigate the sanitary status of urban secondary water supply facilities in Haidian district of Beijing.

Methods: Adopting the quantitative classification table drafted by the Bureau for Sanitation Inspection and Supervision of Haidian district, we carried quantitative classification (A, B, C grade) on all 1725 secondary water supply facilities in Haidian district for two times. At the same time, we collected 20 residential areas with stratified random sampling method.