Unexploded WWII bombs buried in Mer Bleue bog, DND confirms

The Mer Bleue bog was the site of a practice bombing range during the Second World War, before being purchased by the National Capital Commission in 1965. (Trevor Pritchard/CBC - image credit)
The Mer Bleue bog was the site of a practice bombing range during the Second World War, before being purchased by the National Capital Commission in 1965. (Trevor Pritchard/CBC - image credit)

An unknown number of unexploded bombs dating back to the Second World War are buried in Ottawa's Mer Bleue bog, a popular hiking area, the Department of National Defence confirmed Tuesday.

The 3,500-hectare conservation area, which is owned and operated by the National Capital Commission (NCC), is located in Ottawa's east end. The area is also home to several rare species of plants and wildlife, according to the NCC's website.

Andrée-Anne Poulin, a spokesperson for the Department of National Defence, said in a statement Tuesday that a practice bombing range was in active use in the area between 1942 and 1945. The types of munitions dropped included aerial bombs of up to 1,000 pounds (about 450 kilograms).

Declassified documents outlining the presence of unexploded bombs in the Mer Bleue bog were first obtained by the Ottawa Citizen.

Poulin said based on historical maps and aerial photographs, the department knows where the bombs were dropped, but doesn't know how many are there.

Poulin said a bomb disposal team was tasked in 1960 with clearing the former range of unexploded ordnance (UXO), but the nature of the terrain made the job difficult and it couldn't be declared completely free of UXO.

The NCC opened negotiations with the defence department in 1964 to assume ownership of the area, with the intent of using the property as parkland. The commission was made aware of the remaining UXO and agreed to purchase the land in April 1965.

Radio-Canada reached out to the NCC for comment, but the commission declined.

An aerial photo from the Department of National Defence shows the former bombing ranges target area. The small red crosses correspond to impact craters.
An aerial photo from the Department of National Defence shows the former bombing ranges target area. The small red crosses correspond to impact craters.

An aerial photo from the Department of National Defence shows the former bombing range's target area. The small red crosses mark impact craters. (Supplied/ Department of National Defence)

Risk assessed as low

The UXO risk at Mer Bleue has been assessed as low because the impact area was in the bog itself, so the likelihood of anyone coming across the bombs is minimal. Poulin said it won't impact public use of the boardwalks, hiking and ski trails, or any of the site's other amenities.

"The historic bomb impact areas are deep within the bog away from any of the public use areas," she said.

Martin Laberge, associate professor of history of international relations in the department of social sciences at the Université du Québec en Outaouais, agreed any risk to the public is minimal.

"There's a good chance that the munitions are buried quite deep ... so for people to be wading through the marshes looking for these objects would be quite surprising," Laberge said in French.

"And that's without taking into account the fact that they spent years and years in the water, so the chances of accidents happening there are relatively low."