Urban Wastewater and Water Demand Reduction


To meet target concentrations of nitrogen and phosphorus in receiving water bodies, many wastewater treatment plants (WWTPs) are or will be faced with more stringent discharge limits. Many utilities are keen on sustainable solutions to apply to achieve these limits. The conventional approach is to apply nitrification-denitrification and either biological or physical removal processes for P removal. However, these approaches are very costly, placing particular burden on small and resource limited communities. There are many other alternatives to achieve target concentrations of N and P in water bodies which also enable nutrient recovery, but utilities are unsure of the costs and benefits associated with those approaches. Results from model demonstrations conducted in this project will provide guidance to municipalities on most cost effective, reliable, and resilient approaches for nutrient abatement by the urban wastewater sector. Nutrient trading may be a viable option and will be evaluated through CLEAN activities.

Activities for this project support providing data and models required for CLEAN to meet its goals. Five activities are proposed: 1) Model innovative water and wastewater approaches to estimate impacts to water demand, wastewater quantity and quality, and cost for implementation, 2) Models to better manage nutrients in urban wastewater incorporating performance, reliability, resilience and cost, 3) Model Integration and Demonstration Studies, 4) Identify viable water and wastewater management approaches to reduce nutrient loading to receiving water bodies and to recover nutrients and energy from wastewater, and 5) Identify social and policy barriers that facilitate or impede adoption of cost effective innovative approaches. The approach involves expanding the existing Integrated Urban Water Model, applying existing wastewater process models and enhancing models to estimate reliability. Models will be applied to demonstration areas in the study watersheds located in Colorado and North Carolina.


The overarching goal of this project is to assess the effects, costs and likelihood of adoption of various nutrient management strategies relevant to water and wastewater management. Both management approaches, such as water reuse and source separation of urine among others, and wastewater treatment technologies for nutrient removal and recovery (sidestream nutrient recovery ammonia stripping or struvite precipitation, ANNOMOX® etc.) will be evaluated. The objectives of this project focus on exploring the efficacy of approaches for nutrient removal, their cost effectiveness, reliability and resiliency. Scale of application of wastewater treatment for reuse or discharge will be a key consideration in the analyses. In addition, social and policy barriers for adoption of those approaches determined to be cost effective will be assessed.

Resource recovery technologies at WWTP facilities have the potential to substantially improve downstream ambient nutrient concentrations.

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Sybil Sharvelle
JoAnn Silverstein