A REVIEW OF METHODOLOGIES FOR USE IN DETERMINING NUTRIENT CRITERIA IN COASTAL AND ESTUARINE SYSTEMS

摘要

Section 304(a) of the Clean Water Act directs the EPA to develop scientificrninformation on pollutants and to publish "criteria guidance," often expressed asrnpollutant concentration levels, that will result in attainment of designated uses of arnwaterbody. In the case of nutrients, however, the EPA recognizes that there isrnconsiderable variability inherent in nutrient levels and nutrient responses throughoutrnthe country. As a consequence, the EPA is considering determining nutrient criteriarnguidance based on waterbody type, geographical region and designated uses.rnGuidance documents, which are expected to recommend numerical target levels forrnnutrient related variables, are anticipated to be completed for rivers, lakes, andrncoastal waters by the end of year 2000. The purpose of this paper is to explore thernvarious alternatives available with which one could assess the role of nutrient loads inrnestuary trophic status and assist in the determination of target nutrient concentrationsrnfor estuarine and coastal waters.