不列颠哥伦比亚省温哥华的大温哥华水区（GVWD）从位于受保护的山区流域的三个水库向大约180万人提供高纯度、未经过滤的饮用水。1994年，GVWD启动了一项计划，升级其主要消毒设施，以提供贾第虫囊肿的3-log灭活。作为这项工作的一部分，利用每分钟40升的原型工厂来确定两个供水系统中的臭氧需求和衰减率，并估计臭氧氧化对消毒副产物（DBP）形成的影响。本研究的目的是确定臭氧添加对氯需求、DBP形成和生物稳定性的影响。 根据臭氧需求和衰减动力学，进行了一系列现场中试工厂试验，以确定三季水质和温度下贾第虫囊肿和隐孢子虫卵囊3-log灭活所需的臭氧剂量。

The Greater Vancouver Water District (GVWD) of Vancouver, British Columbia, supplies about 1.8 million people with high purity, unfiltered drinking water from three reservoirs located in protected, mountainous watersheds. In 1994, GVWD initiated a program to upgrade its primary disinfection facilities to provide 3-log inactivation of Giardia cysts. As part of this effort, a 40 liter per minute prototype plant was utilized to determine ozone demand and decay rates in two of the water supplies along with estimating impacts of ozonation on disinfection byproduct (DBP) formation. The objective of this study was to determine the effect of ozone addition on chlorine demand, DBP formation and biological stability. A series of on-site pilot plant tests were conducted to determine the ozone dose required for 3-log inactivation of Giardia cysts and Cryptosporidium oocysts for three seasons of water quality and temperature based on ozone demand and decay kinetics.