UPGRADING PRIMARY DISINFECTION AT THE MANNHEIM WATER TREATMENT PLANT: IMPLEMENTING ULTRAVIOLET IRRADIATION AND REFOCUSING OZONE

摘要

The Mannheim Water Treatment Plant (WTP) was constructed in the early 1990s to meet the rising water demands for the integrated Regional Municipality of Waterloo (RMOW) supply system in southwestern Ontario, depicted below in Figure 1. The Mannheim WTP was designed as a fully conventional treatment facility to treat the Grand River source water at a nominal production capacity of 72 million litres per day, which corresponds to 19 million US gallons per day. At this time, the understanding of the Cryptosporidium oocyst issue was in its infancy and design provisions were not made to specifically treat for this pathogen.rnAs part of a continuous improvement program and the result of a Cryptosporidiosis episode during the spring of 1993, the ozone operational strategy was altered from its original intent and directed towards microbial disinfection. This shift in ozone operational strategy has placed an increased demand on the ozone system well above its originally designed purpose. This has resulted in an increase of operational and maintenance (O&M) issues. The 10-year old ozone system is out-dated and requires major capital-cost modifications in upgrades to remain proactive with both the Ontario Ministry of the Environment (MOE) as well as the United States