OTTAWA—Canada’s lakes and rivers are awash in harmful contaminants, but new documents warn the federal government’s murky understanding of the problem is putting the country at risk.
Senior bureaucrats reached that conclusion in a pair of internal reports on contaminants and excess nutrients in freshwater.
The officials warned Ottawa needs to know much more about the contaminants before it can tell how dangerous they are, what happens when they mix together, or where to focus cleanup efforts.
“There are significant gaps in the understanding of contaminants in groundwater in several areas, which hinder the advancement of effective risk assessment and management activities,” says one of the reports.
The reports were produced by working groups of high-ranking civil servants from several departments that the government formed two years ago to study water issues.
The Canadian Press obtained two of the groups’ “draft discussion documents” under the Access to Information Act. The reports, dated December 2008, were only released last month.
One report looked at contaminants in fresh water. The other was on excess nutrients, such as phosphorus and nitrogen, that cause toxic algae blooms.
Giant floating fields of algae have taken over swaths of the Great Lakes, Lake Winnipeg and many other lakes across the country in recent years. The algae suck oxygen from the water and produce toxins that are harmful to fish, humans and other living things.
Run-off carrying agricultural fertilizers, waste water from sewers and industrial pollution are identified as the main sources of nutrients in Canadian fresh water.
The report warns the problem will only get worse.
More human waste will end up in the water as the population grows. More people using more water means there will be less of it to wash away excess nutrients from lakes and rivers, leading to more buildup.
The effects of climate change could also exacerbate the problem.
Heavy rainstorms could overflow sewers, dumping waste water into lakes and rivers, and wash more manure and fertilizer from farmers’ fields into nearby bodies of water. Heavy rain followed by warmer and sunnier weather are the perfect conditions for algae blooms to grow.
The report suggests a national, publicly available source of information on nutrient levels in fresh water could help the government tackle algae blooms.
“Government response to reports of harmful algal blooms is being hampered due to lack of knowledge,” the document says. “Especially about blooms of ‘blue-green algae.’ “
—The Canadian Press
Republished from the Winnipeg Free Press print edition November 10, 2010 A16