The man who sounded the alarm on contaminated water in Walkerton, Ont., warned yesterday that other cities and towns drawing their water from wells may be risking similar tragedies.
Dr. Murray McQuigge, chief medical officer of health for the area around Walkerton, said normally safe water from wells may become contaminated at times of heavy rainfall and flooding.
"If we want to prevent this kind of tragedy from occurring again, we have to look at how we protect and treat our municipal water."
Six people died and more than 2,300 became ill because of the contamination that hit the Walkerton water system late last May.
Dr. McQuigge told a news conference in Walkerton yesterday that a detailed investigation conducted by his office with the help of the federal Health Department traced the contamination to cow manure from a farm near a well supplying water to the community.
"The Walkerton outbreak calls into question the safety of groundwater sources that may be under the influence by surface water, especially under flood conditions," Dr. McQuigge said in his report.
"Historically, groundwater sources have been assumed to be secure and treated with chlorination only," he added. "However, in light of this tragedy, the approach needs to be re-evaluated."
Environment Minister Dan Newman said his ministry would study the report. "Obviously I want to ensure that all the drinking water in this province is protected, and that means deep water wells. . . . That's why we're inspecting them."
There are 630 water-treatment systems in the province. Officials in Mr. Newman's office said about 400 draw their water from wells.
In the wake of the Walkerton tragedy, the government is examining the safety of all the water-treatment systems. So far, it has looked at 420 and ordered about one-third to make improvements, although none of the problems were serious enough to threaten health.
The improvements ordered include better training for the operators of the systems, upgraded equipment to chlorinate the water and more efficient testing of water samples.
But Dr. McQuigge cautioned that a system that tests out acceptably in normal times may come under extra stress during a period of heavy rainfall.
As a result, contamination could enter the water supply with the excess runoff from the rainfall, a problem that would not be detected in drier times, Dr. McQuigge said.
New Democratic Party environment critic Marilyn Churley said Mr. Newman's failure to commit the government to action in light of Dr. McQuigge's report shows the government is still in denial about the Walkerton tragedy.
"How many more people are going to have to die in this province before the minister and the government finally take action to come up with real solutions to the problem?" she asked in the legislature.
Liberal Party Leader Dalton McGuinty noted that the government's Environment Ministry had not warned municipalities about the danger of water from wells after heavy rainfall. Instead, it took Dr. McQuigge, the medical officer of health for the region of Bruce-Grey-Owen Sound, to establish the danger while investigating the Walkerton tragedy.
"It's not a surprise given this government's track record and the lack of priority that they attach to the ministry itself and the fact that they have cut its budget by so much [40 per cent]and let so many staff people go," he said.
Mr. McGuinty said that yesterday's introduction of legislation establishing increased fines for pollution offences is meaningless without the staff to enforce it. "Where are the inspectors? Where are the enforcement officers? Where are the prosecutors?".
He added that the timing was designed to deflect attention from Dr. McQuigge's report.
Dr. McQuigge's report is the most recent and most conclusive finding that the fatal contamination originated from cattle manure on a farm adjacent to well No. 5.
Water from heavy rainfalls in the first two weeks of May apparently picked up this contamination and carried it through the earth and into the well, likely through leaks in the well casing.
The water was chlorinated before it entered Walkerton's water system. But the chlorination was ineffective because of mud entering the well and the water system at the same time.
"This situation emphasizes the importance of secure water sources and adequate water treatment in ensuring a safe water supply to a community," the report concluded.
Dr. McQuigge also warned that testing for contamination, while important, does not ensure safety. By the time a test has been conducted, "you folks have drunk the water," he told reporters.
Walkerton's water crisis
The contamination was responsible for illness in as many as 1,286 people in Walkerton, a town of 5,000, representing 26% of the population. The series of events occurred in May 2000 that led to the contamination of the Walkerton municipal water supply: 1. Unusually heavy rains and flooding. 2. A shallow well subject to surface water contamination located in close proximity to a cattle farm. 3. E. coli 0157:H7 and Campylobacter spp. present in the adjacent cattle herd. 4. A water treatment system that likely was overwhelmed by turbid water.