Volume 43 Number 6
UV: Walkerton Case Study -- Shedding New Light on Water Treatment
After the cold and damp of winter in southern Ontario, Canada, the long Victoria Day weekend in May is celebrated with a sense of eager anticipation for the coming summer. Bernie Reed and his family were in a mellow after-dinner mood on last year's holiday Monday as the news came on TV. The Reeds were shocked to hear the county medical officer had issued a "boil water" advisory for their hometown of Walkerton. Children and seniors throughout the town were seriously ill. An outbreak of E. coli bacteria was believed to be the cause. The town water was no longer safe.
Bernie knows more about water than the average TV viewer. He and his partner, Doug Schaab, own the largest plumbing and heating dealership in the Walkerton area. He routinely sold water disinfection systems to his rural customers. But he, like everyone else in town, had an unquestioning faith in the town water. Bernie was confident whatever problem led to the medical officer's order would be contained quickly. It would be inconvenient but "nothing huge," he thought.
He was wrong.
Walkerton gets on the map
But, over ensuing weeks, Walkerton's water would make news all over the world. This was the largest E. coli outbreak in North American history. Fully half the population of Walkerton would be stricken with illness from the tainted water. Many were hospitalized. Several died. Schools closed. Even at church, parishioners became fearful of shaking hands and risking disease. Six months would pass before Walkerton could turn taps on again.
The problem's magnitude began to reveal itself the day after the boil-water order was issued, when the Ontario Clean Water Agency (OCWA) phoned Bernie at work. OCWA, an agency that operates many larger water treatment plants in Ontario, was taking over the town's water supply and directing the effort to contain the outbreak. Bernie's business, Reed & Schaab ClimateCare, had the area's largest staff of plumbers and OCWA was drafting all the help it could get. As the agency explained what was involved, Bernie could see the effort would be "huge" indeed.
Plenty of questions
ClimateCare had been installing ultraviolet (UV) disinfection systems for over 10 years. But even Bernie couldn't tell customers with certainty that UV was effective against E. coli. As it happens, the head office of his supplier was located in nearby London, Ontario. Bernie's contact there was able to give him the assurances he needed -- at conventional design doses, UV is a proven defense against identified target waterborne pathogens, including bacteria, viruses and other protozoans. Ironically, Bernie learned his supplier was just preparing to launch a new series of UV systems developed specifically for point-of-entry (POE) disinfection. With variable capacities ranging up to 40 gallons per minute, the line would be ideal for residential and commercial installations in Walkerton.
But Bernie was already learning that, where drinking water is concerned, technology alone isn't enough.
Shutting down the water
"It was like going to war," Bernie recalls. "Bunker time. The whole community had to jump in and do whatever they could."
ClimateCare became "command central" for the decontamination campaign. While Bernie's plumbers headed out in OCWA vans, his dispatcher, Elaine Lippert, stayed on the radio to deploy the growing legion of plumbers arriving from all over southern Ontario to help out. According to Bernie, "the plumbers worked from 7 a.m. to 10 p.m. for three weeks straight, but Elaine put in more hours than anyone. She held it all together and still dealt with all the calls and questions from our customers."
Formula for drinking water
In Walkerton, the system was broke, but few people knew where to look for effective alternatives. In Europe, where authorities prefer to avoid chemical treatments that can impact the environment, UV has been used in water disinfection for 90 years. It controls anything that has nucleic acids, including pathogens that cause staph and strep infe