In order to provide high-quality drinking water to the residents, Daqi
ng City started the High-Quality Water Supply Project in 1994. In the
first phase, seven polishing water treatment systems consisting of pre
ozonation, microfiltration (MF), activated carbon (AC) adsorption, ult
rafiltration (UF) or reverse osmosis (RO) and postozonation were insta
lled in various residential districts. The existing low-quality tap wa
ter is used as feed water, and the treated water is distributed to the
customers through an independent network or with bottles for drinking
and cooking purposes. The total treatment capacity of the seven syste
ms is 620 m(3)/d. The seven systems were commissioned separately from
September to November 1997 and have been running smoothly. The perform
ance of the systems meets the design requirements, and the treated wat
er quality meets the European Union Drinking Water Standard. Economica
lly, both capital investment and operating costs are within the initia
l budgets and at rational levels.