WCW24

The average North American has the opportunity to spend an additional 4.5 hours a week in happiness and productivity.  Learn how in this Life Engineering session.  (Want to know what Life Engineering is? Come to find out!)

Hydrogen Sulfide (H2S) causes severe problems in wastewater collection and treatment plants. Equipment corrosion, odor complaints, and operator/public safety are some of the issues routinely encountered with H2S. Chemical dosing is typically used to control H2S, but to better manage facilities and optimize mitigation practices, utilities need more information to understand how H2S behaves throughout the sewer networks and facilities over time. New H2S sensor technologies enable operators to continuously measure H2S in both liquid and gas phases in collections systems and treatment plants. Through their installation, they give a complete and dynamic overview of H2S impacts, providing a path to proactive and data-driven approaches to H2S management. Trends and trouble-spots can be identified before they become problems. The result of this is optimized chemical dosing, minimized odor complaints, prevention of equipment corrosion and premature equipment failure, and protection operator and public safety. These probes are robust, C1D1 rated, and can operate in remote locations. They are easily cleaned, maintained, and calibrated. Importantly, their successful operation has been proven with multiple case studies documenting their efficacy.

In the Spring of 2023, Lethbridge County partnered with Hydrasurvey Ltd. to formulate a comprehensive Lagoon Management Strategy, a sophisticated approach to Risk Management planning of their Wastewater Lagoons. Like many counties, Lethbridge faces the challenging responsibility of managing and upgrading critical infrastructure within constrained budgets. To effectively allocate resources, proactive planning and budgeting for projects is essential. Unlike some types of infrastructure that can be visually assessed and inspected more easily, Wastewater Lagoons present a unique challenge. Being bodies of water, problems often manifest beneath the surface, making it difficult to predict when issues will arise. To pre-emptively address significant problems in their Wastewater Lagoons, Lethbridge County engaged Hydrasurvey to conduct Bathymetric Sludge Surveys on four lagoons in April 2023. These surveys employed the latest RTK GPS mapping technology, single-beam sonar for sludge thickness mapping, manual liner measurements, and sludge sampling to determine disposal criteria. This information was presented in a comprehensive report incorporating a detailed Lagoon Management Strategy. This strategy systematically outlines the dredging and desludging priorities for each cell by ranking the lagoon's capacity occupied by sludge, estimated dry tonnes, dredgeable sludge volumes, and disposal criteria. Armed with this information, Lethbridge County was able to solicit accurate and comparable budgets from dredging contractors, specifying the volume of sludge to be dredged. The strategy also facilitates verification of completed dredging through post dredge surveys. This proactive approach, coupled with the detailed insights gained through the Bathymetric Sludge Surveys, empowers Lethbridge County to navigate infrastructure challenges with heightened efficiency and fiscal responsibility. By addressing potential issues before they escalate, the county is better positioned to make informed decisions, optimize resource allocation, and enhance overall infrastructure management.

Lagoons are common for wastewater treatment in smaller-sized municipalities. Over time, lagoons accumulate sludge that must be cleaned out to maintain storage capacity, reduce odours and meet effluent compliance. The cost of cleaning out lagoons can be high and varies widely depending on the size of the lagoon, the amount of sludge and the options available for beneficial reuse or disposal of the sludge. A high cost of cleaning lagoons can often be a barrier for undertaking this important maintenance procedure. Some options for cleaning out sludge include dewatering lagoons and removing sludge with heavy equipment, dredging sludge with barges, and using lagoon crawlers that drive into lagoons and pump out sludge. A relatively new approach is bioaugmentation of lagoons with microbes that accelerate degradation of sludge in situ. Bioaugmentation is not capital intensive and has been used successfully in other jurisdictions. However, it has not been used extensively in Ontario. Bioaugmentation products are typically proprietary, and the suppliers claim successful use of these products to reduce sludge, Fats Oils and Grease (FOG) and when adding in a collection system, raw sewage loadings. The Town of Bruce Mines and the Ontario Clean Water Agency (OCWA) partnered to trial bioaugmentation in the Town's sewage lagoons as the lagoons required sludge removal and the Town had limited capital funds for the work. The key questions the trial set out to answer is whether bioaugmentation would work in a cold climate, and how much sludge could be removed by bioaugmentation. The results of this study showed bioaugmentation could be an approach to remove sludge from lagoons in situ at a lower cost than traditional methods. In this case study, the results of bioaugmentation exceeded expectations. After one-year of bioaugmentation show a sludge reduction of 6,849 m3, which is a 56% overall reduction across the two cells. Reduction was not equal in the two cells as there was a 40% reduction in cell #1 and 64% reduction in cell #2.

Many communities have either SSS or CSS, which collect stormwater and I/I in addition to sanitary and industrial wastewater discharges. This type of collection system frequently results in the flow capacity of the sewers being exceeded during wet weather events. When the flow capacity of these sewer systems is exceeded it results in sewer surcharging and frequent discharges of wastewater overflowing from the SSS or CSS systems into adjacent streams. Solutions to resolve this problem have included separation of combined sewer systems, transporting wet weather flows in excess of the existing combined sewer system capacity to a storage facility for subsequent treatment at a wastewater treatment plant (WWTP), transporting the excess wet weather flow to the WWTP after expanding its peak flow capacity, or transporting the excess weather flow to a combined sewer overflow (CSO) treatment facility located either at a WWTP or remotely in the collection system. This presentation will review viable technologies for expanding biological capacity with advanced primary treatment and wet weather treatment. Pile cloth media filtration (PCMF) is now being used in a wide range of primary and wet weather conditions within treatment facilities or in the network (overflow sites). The application of PCMF for advanced primary and wet weather treatment has been applied on a range of influent solids conditions from primary influent, primary clarified effluent and combined secondary clarified effluent with the primary influent or primary clarifier effluent. The ability to handle the range of influent conditions allows the technology to be placed in multiple locations within a treatment facility or at remote overflow sites. Also, PCMF is being used in dual treatment applications providing value to a facility across a range of operating conditions. PCMF achieves very high solids removal without chemical addition. The removal efficiency is typically greater than 80% of TSS, with applications demonstrating removal in excess of 90%. This high removal of TSS is also achieved in a very small footprint which is typically 15 to 20% of primary clarification for comparison purposes. The high removal efficiency allows more capacity to be achieved through biological treatment train if used to replace primary clarifiers. This allows more wet weather flows to be treated through the main treatment train. For wet weather only treatment, the technology is being used in auxiliary side-stream treatment trains or in dual use application of tertiary treatment and wet weather flow treatment. The technology spotlight will focus on the many of the projects that are operating or in design. The areas to be covered will be the following: - The performance from operating installations and testing conducted for facilities under construction and/or design for advanced primary and wet weather treatment - Space requirements based on influent condition - Influent water quality and flow information needed for the design of a wet weather system - Handling of waste solids removed during treatment - Automation requirements for wet weather treatment to minimize operator attention - Instantaneous startup capabilities - General operating costs In summary, the technology spotlight will show how the technology of PCMF can be applied in multiple locations within a treatment facility or remote overflow site to help a utility to achieve the following: - Expansion of an existing biological treatment train capacity - Meet facility permit requirements (water quality) - Eliminate untreated wet weather flows