WCW24

In 2018, the City was required to undertake an environmental impact study of the waste stream's effects on the South Saskatchewan River. The purpose of the study was to assess the downstream impact the treatment system residuals will have on the receiving stream and to determine the assimilation capacity of the receiving water body. The study was completed by Clearwater Environmental Consultants Ltd. From the evaluation of the process waste streams, it was found that the CBD, FBW, and FTW streams would not meet discharge requirements and would require further treatment. Following this study, the City was required to construct a residuals management facility before December 30th, 2024, to handle the WTP waste streams and maintain the City's Operating Approval. In 2020, MPE and our design partner AE2S were commissioned by the City to provide engineering services for the detailed design, tendering, and construction of the WTP Residuals Management Facility. MPE/AE2S began with an extensive preliminary design phase, which included a thorough review of the basic design concepts previously established and the development of the final design criteria. Review of final design concepts with Alberta Environment and Protected Areas (AEPA) was also a key component. The strategy utilized for the CBD stream was connecting to existing piping near all the existing clarifiers to reroute the flows to the new Blowdown Transfer Pump Station (BTPS). After reaching the BTPS, the CBD would be pumped to the new Residuals Management Facility (RMF) on the eastern part of the site. At the RMF the CBD would be dewatered for disposal. The FBW and FTW waste streams require additional treatment to avoid any negative impacts on the South Saskatchewan River. The Residuals Clarifier was added for further treatment of the FBW/FTW streams prior to being discharged to the river. The CBD from this process will be transferred to the RMF to go through the same dewatering process as the blowdown from the existing Solid Contact Unit Clarifiers. All liquid residuals from the thickening and dewatering process at the RMF will be pumped to the Residuals Clarifier Building (RCB) for further treatment prior to river discharge. Tendering of this project occurred between the fall of 2022 and the spring/summer of 2023, utilizing multiple contracts. Construction commenced on site in late March, 2023 and will continue through the remainder of 2023, 2024 and into the spring/summer of 2025. Full implementation of the project is required by the end of 2025. This paper provides a background for the entire project, focusing on the design concept development. Discussion on the early phases of construction will also be included.