Dual Research Projects Investigate Regulatory and Technology Nutrient Management Strategies 

Utilities are facing growing pressure to manage nutrients across watersheds. To tackle this challenge, we collaborated with the Water Research Foundation to identify regulatory approaches that encourage holistic nutrient regulatory strategies, treatment optimization schemes that leverage existing infrastructure with a blend of established and innovative enhancements, and effluent management strategies that integrate a One Water planning approach. Our HDR-led team conducted this work through two simultaneous research projects.

Guidelines for Optimizing Nutrient Removal Plant Performance (WRF #4973)

Utilities need a practical guide that outlines nutrient optimization in existing treatment plants aimed at reducing operational costs, improving treatment efficiency and ultimately reducing nutrient discharges. 

Our team understands that different strategies have been implemented to address nutrient management challenges across the country. Numerous states (e.g., Washington) have worked to establish nutrient optimization guidelines. A common element among them is to make the changes affordable and sustainable. The team worked to consolidate guidelines from a wide range of resources into a single compiled set of guidelines.

A guidance document has been developed that includes a compilation of decision trees for users to quickly sort through and find optimization strategies most relevant to their existing treatment process. Most treatment plants do not currently remove nutrients. As such, the document includes a set of strategies that provide some degree of nutrient removal by modest process changes, such as diverting effluent, sidestream treatment or other means. For plants that already practice nutrient removal, the guidance provides a means to further reduce nutrients, reduce costs or improve nutrient removal reliability. For each strategy identified, fact sheets are referenced that provide detail on implementation, literature references and examples applications.

The team has further developed the guidance document into a user-friendly web-based tool, based directly on the decision trees. The Path to Nutrient Optimization web tool leads users from their specific water resource recovery facility type, treatment process, nutrients of interest, and objectives to a list of optimization strategies that can be evaluated for implementation. Each strategy includes fact sheets on specific topics that provide additional details including, but not limited to, application, benefits, limitations, and considerations for operations and management, design and costs. The guidance document and web tool present a wide range of strategies that address various sizes of utilities in a wide geographic area, provide a pathway that avoids stranded assets and create a stepwise, affordable way to manage nutrients.

Holistic Approach to Improved Nutrient Management (WRF #4974) 

This project engaged both point and nonpoint source nutrient dischargers, regulatory agencies and other watershed stakeholders to develop a holistic framework that advances watershed-based nutrient management approaches in new and improved ways. 

The team researched and developed a regulatory framework based on a holistic understanding of watersheds through Practices, Policies and Partnerships. This framework provides a structured process with key success factors that can be tailored to develop holistic watershed-based nutrient reduction plans. Such balanced plans that consider the three Ps should yield more effective and efficient implementation focused on consensus-based outcomes that provide greater net environmental benefits (e.g., nutrient trading). The framework also provides a diagnostic lens to identify missing elements of existing nutrient reduction efforts that have not achieved planned outcomes.

Through this framework and within each element, the team addressed the overarching themes of climate change impacts and environmental justice challenges.