EPA has added updated U.S. Geological Survey (USGS) SPAtially Referenced Regressions On Watershed attributes (SPARROW) data to the nitrogen and phosphorus pollution data access tool, a tool intended to help states develop effective nitrogen and phosphorus source reduction strategies. SPARROW is a GIS-based watershed model that integrates statistical and mechanistic modeling approaches to simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and factors affecting nutrient fate and transport.