R.V. Anderson Associates Limited (RVA) begins construction of an innovative Head House facility upgrade at the Sudbury Wastewater Treatment Plant that will reduce costs and improve the overall quality and efficiency of its operations. A second level of headworks will be retrofitted inside the existing facility directly above the old, thereby raising the hydraulic gradient and eliminating the need for costly intermediate pumping.
RVA’s innovative design approach accommodates the existing infrastructure and saves approximately half the cost of building a new headworks facility. An added design challenge was to maintain minimum treatment throughout the Head House during construction. A bypass system was not a viable option since its high cost could have negated the savings of upgrading the existing infrastructure and removing the pumping station. Instead, the design takes advantage of the current configuration’s redundant treatment streams and allows for one system to be decommissioned, isolating the screens and detritors for maintenance.
Construction will commence directly over the decommissioned treatment stream through a series of suspended concrete slabs/channels and backfilling, while still maintaining at least half of the treatment capability. Raw sewage pump forcemains at the existing pump station will be extended to about 2.5 m and new elevated channels will be constructed from the station, through the Head House and to the aeration system.
Upon completion of this project, the City will realize the benefit of reduced maintenance costs, operational costs, process interruptions and bypassing risks, while noting improved effluent quality, air quality and the overall working environment. This upgrade is set to increase headworks treatment capacity and comply with the most recent building, fire and safety codes.
This project also features added benefits to improve the overall quality of the facility and reduce future maintenance costs. Benefits include rock tunnel gate replacements, implementing new odor control technologies and a new preliminary treatment train, consisting of 6 mm automated screens and Vortex degritting. The contract was awarded in May 2013 for $10.7 million. The project is currently in the construction stage, with substantial completion anticipated for November 2014.