July 22, 2019; Liverpool, NS: An odour has been occurring at various times near Liverpool, Bristol Avenue, and Highway #3, Brooklyn. Region employees continue to proactively consult with experts to locate causes of the odour and pursue potential solutions. The Municipal Sewage Treatment facility located on Hank Snow Drive continues to meet all regulatory effluent requirements.
As local wetlands transitioned from winter/spring/summer conditions, it became more evident that the odour was increasing from the RQM facility, and decreasing from the wetlands, especially during the recent week of warm sunny weather. It is expected that the water in the primary lagoon experienced a roll over in recent weeks, significantly contributing to the odour. The prevailing wind direction generally dissipates odour, however certain wind directions and humidity levels can result in a noticeable odour in various areas of the community. It should be noted that the New Minas area also experienced a similar odour issue this spring. While the wastewater lagoon odour is not pleasant, as in other locations, it is not indicated to be a health hazard.
Proactive efforts in past weeks included the flushing of our sewage lines from Milton, as well as on Bristol Avenue, to the sewage treatment plant. Skimming of the surface of the primary cell at the sewage treatment facility was completed to remove any fats or oils which may be present, which could potentially generate an odour.
The RQM Waste Water treatment facility and aerated lagoons were constructed in 2001 with a projected dredge cycle of from 25 to 30 years. It was determined through expert opinion that while dredging was premature at 18 years of operation, de-sludging should occur as soon as possible due to the existing odour issue. The future dredging cycle for the primary lagoon will be significantly extended after the de-sludging process is completed. The sewage treatment facility currently operates at less than 30% of its design capacity.
The contractor who performs de-sludging work was fully obligated with existing contracts, and there is limited availability for this specialized service to de-sludge the primary lagoon through their odourless process. This company is currently on site to begin the de-sludging operation this week. This projected expenditure of $150,000 was approved by Council, with actual dredging being expected to require two weeks to complete.
Other professionals in their specific fields are in the process of preparing research reports and staff will continue to research and consult with experts in their areas of expertise.