Walkerton should be a wake-up call

June 7, 2000 - According to the United Nations, more than 1.4 billion people in the world do not have access to safe drinking water. Unfortunately, we can now add the residents of Walkerton, Ontario to that list.

The recent tragedy in Walkerton should be a warning to Canadians that we cannot take our clean and plentiful fresh water supply for granted. Canada is home to more fresh water than any other country in the world, but we are not immune to pathogens that can cause illness and even death. And unless we increase our diligence over water safety and find and clean up the source of contaminants, this disaster is bound to repeat itself.

Although the media have focussed largely on what events directly led to the fouling of the town's water supply with E. coli, the larger issue is one of environmental health, and how it can affect human beings.

The area immediately surrounding Walkerton is home to many cattle and dairy operations, as well as factory-style hog farms. So far, the evidence suggests that the bacterium responsible for the outbreak, E. coli 0157:H7, likely originated from animal waste from one or more of these farms.

This should not be surprising. According to the Globe and Mail, a Health Canada study published last year found that 32 per cent of wells in rural Ontario exceeded the acceptable standards for fecal contamination (a common indication of the presence of pathogens like E. coli). The study also noted that there was a strong association between E. coli infection and cattle density. Cattle density around Walkerton is among the highest in Ontario and rates of E. coli infection in the area (even before the Walkerton outbreak) were also found to be very high.

Large, high-density cattle farms and factory farming methods for hogs and chickens have become the norm in North America, replacing many smaller farms. Industrial style hog farms, for example, have spread across the country, especially in Ontario, Quebec and Alberta. Some 18 million hogs are now raised for meat in Canada, one third of which are bound for export. Southern Ontario's Huron County alone is home to 400,000 hogs.

By raising animals in high densities we have, in effect, created crowded cities of animals, with the waste to match. The US-based Environmental Defense Fund estimates that hogs, for example, each create nearly two tons of urine and feces every year. This waste is usually held in large, open tanks or pits before being spread onto farmer's fields. A recent article in American Scientist reported that lagoons and sprayfields for animal waste near streams and watercourses may be significantly degrading water quality and endangering human health. As well, a 1999 study by the University of North Carolina found that industrial hog farms reduce the health and quality of life of people living in the surrounding area.

E. coli 0157:H7 (which is thought to have originated from Argentinian beef) is a particularly dangerous bacterium because a person exposed to fewer than 10 organisms can become ill. But other pathogens are also spread through animal waste, including Salmonella, Cryptosporidium, and Campylobacter jejuni. In 1994, when the water supply for Milwaukee, Wisconsin became contaminated with Cryptosporidium from farm animal wastes more than 400,000 people became ill.

The move to more densely-populated farms and factory farms creates large volumes of waste that the surrounding environment may be unable to absorb. Clearly, strict regulation is required. We need either fewer animals per farm, or in some cases, full waste treatment as we would expect of a large city. One of the reasons factory farming lowers costs is because the full impact to our environment and health is being passed on to the rest of us.

Merely adding more chlorine to our water to kill bacteria is not good enough - our drinking water is not a dumping ground for waste. Canada should be a world model for clean waters and the healthy ecosystems needed to maintain them, not an example of what can go wrong when we become complacent.