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Technical Report

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ecology workshop, water quality monitoring.


The U.S. Environmental Protection Agency (USEPA) has been encouraging states to accerlate their efforts in developing numeric nutrient criteria to promulgate within respective water quality standards and regulations. Based on USEPA recommendations, many states are pursuing nutrient criteria development by assessing frequency distributions and stressor‐response relationships in historical databases, various special studies and the literature. The mini‐workshops described here were targeted toward state agency personnel and stakeholder groups with an interest in understanding statistical techniques that could be used to aide, guide and support numeric nutrient criteria. An initial workshop was conducted at the USEPA Regional Technical Assistance Group meeting in February 2010, but it was poorly attended because of the development of harsh weather and travel conditions. The limited state and USEPA personnel in attendance gave a positive response, and subsequent workshops were planned for each state agency with regulatory authority to develop water quality standards. The workshops were designed to be one working day, starting at 0900 and ending at 1600, and the topics covered included: workshop goals, objectives and tasks; measurement and ecological indicators of water quality impairment by nutrients; basic statistical methods; advanced statistical methods; and application of the statistical methods and interpretation of results. The number of participants varied from 5 at one workshop (participants specific to state agency developing numeric nutrient criteria) to over 20 (where various state agencies and stakeholder groups were represented). The series of topic presentations were followed by two group exercises that put the statistical tools discussed into action, where smaller working groups had to suggest numeric nutrient criteria for a watershed with ample data and then one with a very limited amount of data. The case studies were hypothetical in nature, but the stressor‐ response relationships shown mimicked those observed in aquatic systems and reported in the literature. The numeric values were defined only as nutrient, not specifically nitrogen or phosphorus; the intent here was to keep this a more open and unbiased exercise, especially for states that might have promulgated specific nutrient criteria. The results of the workshops were not specifically recorded, allowing the participants freedom to present, discuss and criticize without formal record. The proposed numeric nutrient criteria did vary between smaller working groups within a given workshop, but the range proposed was similar across workshops. The workshops were not intended to provide training so that the participants would walk away with the knowledge to actively pursue the techniques discussed. Rather, they were intended to provide a foundation for participants to understand what tools are available for the process of numeric nutrient criteria development and to be exposed to the potential pitfalls and benefits of various approaches. Overall, the feedback from all of these workshops was overwhelmingly positive by the states

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