A water-quality study of the Neuse River, N.C., based on data collected during 1956-77 at the U.S. Geological Survey stations at Clayton and Kinston, employs statistical trend analysis techniques that provide a framework for river quality assessment. Overall, water-quality of the Neuse River is satisfactory for most uses. At Clayton, fecal coliform bacteria and nutrient levels are high, but algae and total-organic-carbon data indicate water-quality improvement in recent years, due probably to a new wastewater treatment plant located downstream from Raleigh, N.C. Pollution was determined by subtracting estimated natural loads of constituents from measured total loads. Pollution makes up approximately 50% of the total dissolved material transported by the Neuse. Two different data transformation methods allowed trends to be identified in constituent concentrations. The methods recomputed the concentrations as if they were determined at a constant discharge over the period of record. Although little change since 1956 can be seen in most constituents, large changes in some constituents, such as increases in potassium and sulfate, indicate that the water quality of the Neuse River has noticeably deteriorated. Increases in sulfate are probably largely due to increased long-term inputs of sulfur compounds from airborne pollutants.
