Weight-of-Evidence: Application for Transparent and Defensible Nutrient Criteria Development

This presentation describes overarching principles and essential steps of a WoE process and how the process aligns with criteria development phases; provides a suite of state-of-the-art WoE methods to combine diverse information; and provides examples for communicating the WoE process and conclusions.

Impact/Purpose

Weight-of-evidence (WoE) is one EPA-recommended approach when developing numeric nutrient criteria. According to state and tribal nutrient managers, additional advice about how to conduct the process would be valuable. We describe overarching principles and essential steps of a WoE process and how the process aligns with criteria development phases; provide a suite of state-of-the-art WoE methods to combine diverse information that are appropriate for different evidence and decision contexts that may be encountered by state, tribal, and territorial nutrient managers; and provide examples for communicating the WoE process and conclusions. With this work, we help maximize the use of all available evidence during the criteria development process, assist states in deciding which techniques to use given unique evidence, resource, and timeline constraints, and further strengthen transparency and defensibility.

Citation

Ridley, C., D. Kaylor, S. Lee, Jesse Miller, Sam Penry, AND K. Schofield. Weight-of-Evidence: Application for Transparent and Defensible Nutrient Criteria Development. Utah Lake Science Panel, Salt Lake City, UT, September 05, 2024.