August 12, 2019: As noted last week, the Municipality has confirmed that after a review of the tidal wetland by an independent wetlands and environmental expert that the lands adjacent to Hank Snow Museum are not the cause of the extreme odour during certain times of the day over the past several weeks.
During the past week, de-sludging of the primary lagoon cell as part of the South Queens Sewer Treatment Facility in Liverpool continued without any delay or interruption. This process is expected to be completed by the end of this week. When completed, odour associated with the Sewage Treatment Plant will be reduced significantly.
Additionally, air quality testing was performed on July 16, 2019, which included all of Liverpool and parts of Brooklyn and Milton. The tests performed collected air quality along streets at short intervals and tested for both hydrogen sulfide (H2S) and methane (CH4) gases. While there are no legislated or regulatory parameters around methane gas levels, all of the test samples showed levels that were insignificant. Methane is odorless and non-toxic to humans.
The tests for hydrogen sulfide showed elevated levels at three points around the actual sewage lagoons on Hank Snow Drive with several other locations around the lagoon showing levels under provincial regulatory levels. No areas of Liverpool, Brooklyn, or Milton outside of the lagoon cells showed any levels of H2S above the guideline limit of 3 parts per million in an hour (3 pphm/hr). The average concentration reading for all three communities was .027 pphm/hr with many points showing 0, including areas just outside the sewage lagoons. The tests were conducted by an independent agency that specializes in monitoring emissions and their location.
Additionally, municipal staff carried out further testing along Milton Road, Liverpool, on July 31, 2019. This testing took place at two manhole locations during two different pumping cycles where a gas detector was used to detect for hydrogen sulfide (H2S) and methane gas (CH4). At one and two foot measurements above both manhole locations, no gases were detected.