Report fails to clear air over eggy stink at Rideau station

Some LRT passengers have compared the persistent odour at Ottawa's Rideau station to the stench of rotten eggs, but an air quality report conducted by an outside firm has found no issues with the environment at the underground stop.

Buller Crichton Environmental measured air samples taken at five locations at Rideau station on Feb. 6, 2020.

According to the report, the indoor air quality test was prompted by concerns about "an odour which is reportedly associated with water infiltrating the tunnel system adjacent to the West platform of the Rideau Station."

In late January, riders took to Twitter to complain about a smell that made some gag. It was so strong, some riders said, it lingered in the train car even after leaving the station.

The smell differed from the aroma at Parliament station, which passengers likened to sewage. (It turned out that's precisely what it was.)

Testing inconclusive

The testing at Rideau was carried out at locations specified by Rideau Transit Maintenance, which were in turn based on complaints from the public, Buller Crichton's report said.

"Each location was assessed, and measurements were recorded."

The scientists measured oxygen content, hydrogen sulphide (none reported), lower explosive limits of combustible gases (none reported), total volatile organic compounds (none reported except near the Williams Street entrance, where levels were below Health Canada standards and "not considered elevated"), carbon monoxide (none reported), carbon dioxide ("well below" limits) and relative humidity, which was found to be acceptable.

The report makes no conclusions about the source of the eggy smell.

"No recommendations are warranted based on the air quality sampling, and [Buller Crichton Environmental] understands that the source of the odour within the Rideau Station is currently being mitigated by Rideau Transit Maintenance," the report said.

Rideau Transit Group said in February the stink was caused by "stagnant water" seeping into the underground transit system, and said it would use grout to seal any cracks in the tunnel wall.