Fixing a damaged sewer pipe that's been getting some commuters' noses out of joint at Parliament station is taking longer than expected, the city says.

Sewage has been seeping into the LRT tunnel since before its completion, according to rail construction program director Michael Morgan.

"During the construction of the tunnel, a municipal sewer in proximity to Parliament Station was punctured by a rock anchor," Morgan explained in an email to CBC.

The city discovered the puncture on Aug. 9 during a routine camera inspection of the sewer, he said. The Confederation Line opened to the public more than a month later.

Rideau Transit Group (RTG) was tasked with developing a plan to deal with the issue and begin repairs on Nov. 4. The work was supposed to wrap up by Nov. 28, but Morgan said the new target date is Dec. 13.

Crowds growing <a href="https://twitter.com/OC_Transpo?ref_src=twsrc%5Etfw">@OC_Transpo</a> Parliament Station. Four trains have already gone by on the other side going east and there is a NASTY sewage smell <a href="https://t.co/Y2H5a3oRiH">pic.twitter.com/Y2H5a3oRiH</a> —@AlysonFair

"The repairs are taking longer than expected," Morgan said, adding the work is being performed overnight to minimize disruption.

The job involves removing the rock anchor, sealing the puncture in the sewer line and relining the tunnel, he said. Morgan did not say whether that would resolve the odour issue for good.

Rail construction program director Michael Morgan, right, speaks at Ottawa city hall on Dec. 3. (CBC)

During a marathon transit commission meeting on Nov. 6, Morgan told councillors the "working theory" was that a damaged pipe was causing the smell passengers had been noticing at Parliament station.

"We're hoping [the repair job] helps resolve part of the smell," he said at the time.

At a meeting in September, OC Transpo boss John Manconi opined the smell could be due to "moisture" pooling in the LRT tunnel.