Modular, Decentralized Wastewater Treatment: A Promising Solution for the American Southeast and Beyond

In water-stressed regions around the world, a dearth of resilient water utilities is jeopardizing access to basic needs such as piped drinking and irrigation water. The availability of this water is heavily tied to utility management of wastewater as a resource to reverse growing supply pressure on freshwater sources, something which the American Southwest has dealt with head-on with its established aquifer and reservoir infrastructure. However, wastewater treatment and reuse infrastructure has become even more challenging for utilities in the region due to the growing impact of climate change-proliferated droughts. While technologies like MBR (Membrane Bio Reactors) and MABR (Membrane Aerated Biofilm Reactors) are being readily implemented as creative reuse solutions for the region, innovation in utility planning will be just as valuable. Further, the need for innovative infrastructure strategy applies to A) densely populated cities with limited space to add centralized utility infrastructure, B) new towns or suburban regions where utilities need to be quickly built and C) irrigation infrastructure that needs to be built or improved (i.e., 2021 Lake Mead crisis). Given these challenging scenarios, Modular Decentralized Wastewater Treatment (DWT) is a compelling new solution gaining traction globally. These systems are crucial for the Southwestern US and beyond in the fight against 'Day Zero' (including Cape Town itself) due to their associated affordability and speed of implementation. When implemented correctly, Modular DWT can also deliver the following benefits: - Augmented biological load removal capacity (depending on the technology used) o Can extend to nutrient removal in order to reduce coastal 'dead zones' - Minimized piping infrastructure and land usage based on accurate fulfillment of treatment requirement - Can be easily deployed in regions with Combined Sewer Overflow (CSO) issues as a standby unit -Simplified sludge handling and disposal due to point source treatment - Impacts of system downtime can be reduced due to distributed approach and standardized IoT Integration (rather than relying on one custom, centralized system) Our paper will identify hotspots for the next 'Day Zero' scenarios and how what a modular DWT program there might look like.