The Greater Vancouver Regional District (GVRD) supplies water to 1.9 million people from three coastal mountain watersheds. Water quality concerns identified include waterborne disease risks associated with Giardia and Cryptosporidium, episodes of elevated turbidity, bacterial regrowth in the distribution system, and corrosive water. To address these concerns, the GVRD has initiated a $300 million capital program to upgrade its treatment capabilities that includes two 1200 ML·d1 ozone and corrosion control facilities, a 1000 ML·d1 filtration plant, and an ongoing program of rechlorination stations and distribution system improvements. This paper provides an overview of the GVRD's drinking water treatment program and related initiatives. These include the decision-making process related to using ozone without filtration, the process selection and selected project delivery method for the Seymour filtration plant, and, lastly, the ongoing secondary disinfection program which includes unidirectional flushing, reservoir exercising, environmental management, and remote data monitoring and data evaluation using a geographical information system application.Key words: water quality, protozoa, ozone, direct filtration, rechlorination, remote monitoring, GIS.
