Wastewater treatment plants are increasingly challenged by extreme weather. Such events will only become more frequent and intense in a changing climate. At the same time, much of the Nation's wastewater infrastructure is past or near the end of its design life. Many new treatment technologies have been proposed to enhance the sustainability and efficacy of these aging treatment facilities. The proposed research is focused on addressing the challenge of improving sustainability in the face of increasing demands on service. This will be achieved by addressing three specific objects. First, researchers will identify factors that make wastewater treatment plants more resilient to extreme weather. The objective will determine which technologies can improve resiliency, sustainability, and treatment performance. The final objective will be to build models to facilitate decisions on where to invest in infrastructure improvement to maximize resiliency. Successful completion of this research will have broad impacts on industry and society. These include improving treatment performance, reducing plant downtime following extreme weather, and reducing the need for overdesigned infrastructure. Added benefits to society include potential improvements in public health and reductions in economic and environmental costs associated with sewage pollution. In addition, the project will create opportunities for underrepresented groups to work on nationally relevant engineering challenges in major urban areas and engage directly with industry and utilities via hands-on training.
The proposed work advances fundamental engineering and science related to resiliency of wastewater treatment plants (WWTPs). The objectives of the proposed research are to: i) quantify the resiliency of a suite of full-scale WWTPs in Houston, TX and Washington, DC to wet weather events and identify features of a resilient system; ii) quantify the resiliency of emerging technologies using modeling and pilot-scale studies; and iii) evaluate the impact of upgrading individual WWTPs on community-wide resiliency as a function of scale, configuration, and connectivity. Measures of resiliency account for both the magnitude of performance reduction and the time to recover performance. Full-scale WWTP sampling will be performed to quantify resiliency metrics for a range of systems, and pilot-scale testing of emerging biofilm-based treatment strategies will be performed to understand how process configuration and biofilm geometry impacts resiliency. A priori, biofilm-based systems are expected to be more resilient to wet weather events because the microbes carrying out the treatment are immobilized and not prone to "wash out" compared to suspended-growth systems ubiquitous to most urban WWTPs. Results from the pilot- and full-scale resiliency assessments will be used as input to a systems-level model to identify candidates for WWTP process intensification to enhance community-wide resiliency. The proposed research is the first to perform a quantitative assessment of resiliency for a range of WWTPs. Successful completion of this research will lay the foundation for incorporating resiliency metrics in the design, evaluation, and planning of future wastewater infrastructure to ensure that advances in process intensification do not come at the expense of process resiliency. Insights gained will inform best practices for the enhancement of wastewater infrastructure resiliency in the face of climate change.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
