An update on the development of numeric nutrient criteria in the United States: a forest industry perspective

摘要

Considerable effort has been spent by state and federal environmental agencies and nongovernmental organizations in the United States in recent years related to develop numeric water quality criteria for nitrogen and phosphorus. Driven by concerns over the negative water quality impacts that can result from excessive levels of these nutrients, the development of numeric criteria has had a prominent place in debates over the most appropriate and scientifically defensible approaches used to prevent and manage nutrient pollution. Recently, numeric nutrient criteria have been adopted for inland fresh waters in two states that are significant to the forest products industry, Wisconsin and Florida, and efforts to develop and finalize numeric nutrient criteria in other such states continue. One of the most significant challenges in developing numeric nutrient criteria that are useful in water quality management is the high degree of variability frequently observed between nutrient concentrations and associated measures of biological or ecosystem response such as algal growth or changes in macroinvertebrate and fish communities. Relatively simple approaches for criteria development may result in criteria that are poor predictors of biological or ecological condition, leading to management decisions that have a high probability of error. This paper describes several approaches being taken in a number of forest product industry states in the US to manage nutrient pollution. It includes information on the types of numeric nutrient criteria that have been adopted or are being considered. The use of decision error analysis to evaluate candidate numeric nutrient criteria is also described.