Wastewater Treatment Strategy: Achieving Better, Faster and Cheaper
Better, Faster and Cheaper: it is often mistakenly assumed that one of the three objectives must be sacrificed in favour of the other two. But with the right contract mechanism and selection of innovative technology, all three can be achieved.
Owners have utilized a spectrum of contract mechanisms to procure wastewater infrastructures including:
- EPC: Engineering, Procurement, Construction
- EPCM: Engineering, Procurement, Construction Management
- DB: Design, Build
- DBO: Design, Build, Operate
- DBOM: Design, Build, Operate, Maintain
- DBOF: Design, Build, Operate, Finance
- DBOT: Design, Build, Operate, Transfer
- P3: Public, Private, Partnership
- IPD: Integrated Project Delivery
Certainly, one size doesn’t fit all.
One of the keys to achieving a better design is the definition of influent/effluent characteristics that consider not only natural variability but also the set of upset conditions. Regardless of the process, Aquen connects with our network of experts across North America to help us anticipate the unexpected and ensure our designs are both robust and reliable. These experts also help us select leading edge technology and equipment that has been proven in similar applications.
The key to executing faster is the elimination of non-value-added steps that consume schedule. We maximize the time spent upfront for better planning and more comprehensive technology selection. Our work flow frees up time for improved procurement processes and more time for competitive pricing and vendor negotiations.
Finally, cheaper can be accomplished by streamlining the design process. We utilized artificial intelligence and automated design tools to streamline front end engineering design. By accelerating project execution by linking parts selection with process instrumentation diagrams and 3D layouts, we make sure that designers, constructors and operators can work together to select an optimal design.
Let’s see how better technology selection can offer multiple options for replacing antiquated lagoon systems.
Across Western Canada, there are hundreds of lagoon systems that operate under a Code of Practice and discharge to the headwaters of prairie watersheds over a short period of time. In addition, the Fisheries Act includes the Wastewater Systems Effluent Regulations (WSER) that impose additional effluent quality criteria not covered within a Code of Practice. As household, industrial and commercial wastewater volumes continue to grow, many of these systems have reached their treatment and storage capacity. These limits may be encountered in some or all of their anaerobic, facultative or storage cells, with the solutions often coming down to expansion or replacement. Increasingly, we are finding that optimization can offer a superior answer.
We’ve looked at a number of treatment systems that are available within optimization strategy, including:
- Lagoon Expansion: increasing the footprint of anaerobic, facultative and storage lagoon infrastructure to improve performance under the existing Code of Practice;
- Membrane Bioreactors for Wastewater Discharge: installation of a modular membrane biofilm system (ie. Veolia’s Biosep™, Suez’s Leapmbr™ or Bishop’s BioCord™) within the existing lagoons to improve contaminant removal;
- Aerated Lagoons: augmenting oxygen levels to extend the effectiveness of facultative processes to overcome lower temperatures and reduced solar energy;
- Submerged Activated Growth Reactor (SAGR): installation of a post-lagoon fully-aerated buried stone bed (ie. Nexom™) to improve removal of ammonia and reduce vulnerability to colder temperatures;
- Biological Nutrient Removal (BNR) reactors: traditional rectangular (ie. Banff WWTP) or concentric-ring (ie. Jasper WWTP);
- Filtration Screening System: mechanical system (ie. Baleen™) for primary removal of grit, suspended solids, oil and grease upstream of aerated lagoons;
- Moving Bed Biofilm Reactor (MBBR): a modular attached-growth treatment process using palm-sized plastic media and aeration system (ie. Sapphire™) to remove BOD and nutrients;
- Membrane Straddle Plant for Reclaimed Water Quality: insertion of a small-footprint modular membrane system (ie. Swirltex™) and repurposing the existing lagoon infrastructure to optimize performance and reduce the footprint of agricultural land required for increase lagoon sizes; and,
- Algae cultivation: harvesting of residual nutrients within engineered controlled-growth media (ie. Symbiotic BiotekTM)
By fine-tuning the technology selection, integrating low-carbon power sources and maximizing the beneficial reuse of treated effluent/biosolids, it is possible to significantly improve the quality of effluent and enhance the downstream receiving environment. Key factors in selecting a technology include: modularization (to reduce field construction costs and improve build quality); energy-efficiency (by using real-time process control to respond to variable inflows); robustness (reduced vulnerability to process upsets); and reliability (selection of quality materials with proven low life-cycle costs). Often our analysis combines experience-based CAPEX and OPEX estimates, emphasis on mature supply chains and confirmation of timely troubleshooting and repair services.