Unpleasant Odour in the Bondville Street Area

Over the past few days, the Town has been informed of an unpleasant odour in the Bondville Street area, more specifically between Montagne Street and Richard Street.

This occasional nuisance during periods of low water levels is not a new phenomenon. It has been observed for several years, as some residents in the area have noted. However, the phenomenon is particularly pronounced this year, both in terms of the intensity of the odours and the area affected.

Conditions conducive to odour formation

The low precipitation levels recorded in recent weeks may be contributing to the situation by reducing the amount of stormwater entering the sewer system. This results in lower flows, more concentrated wastewater and longer retention times in certain sewer pipes and pumping stations. Combined with high temperatures, these conditions promote the formation of hydrogen sulfide (H₂S), a gas responsible for the characteristic odours associated with wastewater. In the past, these episodes tended to diminish or even disappear when precipitation returned.

It is also important to note that the sanitary sewer on Bondville Street is a major trunk sewer in the municipal network, conveying wastewater from several areas to the treatment facilities.

Condition of the sewer system and planned work

Following the reports received this year, a camera inspection was carried out to assess the condition of the sewer system and determine whether there was a possible accumulation, blockage or other anomaly. The inspection did not reveal any new significant anomalies. However, an obsolete section of the sanitary sewer, located between Harvey and Montagne streets (85 m), had previously been identified following a break that occurred this spring. Its replacement is scheduled for this fall.

The current condition of this section may cause more turbulent flow, thereby promoting the release of gases already present in the wastewater. This section may therefore be contributing to the localized increase in odours currently being observed, without necessarily being the primary cause. Its replacement will improve flow conditions in this area.

The Town will continue to monitor the situation and may conduct further investigations to better identify the various factors contributing to the phenomenon and, if necessary, assess potential solutions to reduce its intensity and recurrence.