CONSTRUCTION ESTIMATING NEWS (update by every month)

Documents show LRT construction concerns mounting for city

OTTAWA — Tree roots, vibrations in downtown buildings and concerns about a federal government research lab kilometres away have been some of the city’s worries as it prepares to build its light-rail line, newly released documents show.

It is now examining how best to build the 12-kilometres of light rail, as well as the 2.5-kilometre tunnel underneath the downtown, with as little disruption to the surrounding area as possible.

The memos and letters obtained by the Citizen under federal access to information laws show just how complex construction of the project — which Mayor Jim Watson has deemed the largest of its kind in Ottawa’s history — is going to be.

Many of the sticking points have to do with the multiple layers of government approval required for construction projects in the capital region.

Among the items the National Capital Commission has asked the city to address was a mature white elm located close to the National Arts Centre.

The city commissioned a report by IFS Associates, an Ottawa-based urban forestry consulting firm, in response to the concerns. It found the tree wasn’t going to live as long as previously expected because construction will reduce its “rooting area” by 80 per cent.

“Such a drastic loss of roots and reduction in rooting area will greatly stress the tree,” the report reads, “leaving it prone to future attack by insects and diseases and likely causing the tree’s physiological decline.”

The report recommended several measures to reduce the effect construction will have on the tree. These included erecting a barrier of wood around it so that construction workers don’t trample the roots and cleanly cutting any roots with a pruning shear or a saw wiped with alcohol.

The city decided in early March to move Rideau Station, which was previously supposed to be built in the area close to the NAC, further to the east. That means workers no longer need to worry about the tree, wrote Jocelyne Turner, spokeswoman for the city, in an email.

However the initial concerns still forced the city to pay for the report, she wrote.

The light-rail project is currently budgeted to cost $2.1 billion. City staff say it’s necessary to alleviate gridlock of buses in the downtown core, which they say are currently at capacity during rush hours.

The city will need to deal with a number of other concerns from the federal government before it can go ahead with the project.

Even a research lab about 5.5 kilometres away from the light rail line isn’t immune from the federal government’s concerns. Researchers at the Geomagnetic lab on Anderson Road close to Innes Road and Highway 417, asked the city to look at how the light-rail line will affect their work monitoring the earth’s magnetic field.

The department responsible, Natural Resources Canada, has told the city it is worried the new rail line would create additional noise. This would make it impossible for researchers to differentiate between what the earth is creating and what light rail is, it said.

“Studies conducted by NRCan scientists, assuming standard LRT technology, calculated levels of magnetic noise that exceed international standards for magnetic observatory operation,” one of the documents reads.

The city responded in a letter in August 2011 that said their estimates showed the lab would not be affected, but the federal government department’s concern about the matter persisted.

The municipality will need to address those and other concerns before it can get environmental assessment approval for the project, wrote the City of Ottawa’s Turner.

“The city is confident that the current process will address their concerns,” she wrote.

There are also concerns about how construction will affect organizations that operate in the city’s downtown core.

Officials with the National Arts Centre, where the National Arts Centre Orchestra regularly holds concerts and does recordings, are “worried about noise disturbance,” another document indicates.

Staff have to wait to hear what measures the company that submits the winning bid to build the line proposes for mitigating sounds and vibrations during concerts before they can know how they’ll be affected, said Carl Martin, a spokesman for the NAC.

The city is also keeping an eye on how the Canadian Broadcasting Corporation’s Queen Street building will be affected, the documents show. CBC Ottawa staff referred questions to Marc Chartrand, the corporation’s manager of technical operations, who did not return requests for comment.