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The Point-Source Load Estimation Tool (PSLoadEsT) provides a user-friendly interface for generating reproducible load calculations for point source dischargers while managing common data challenges including duplicates, incompatible input tables, and incomplete or missing nutrient concentration or effluent flow data. Maintaining a consistent method across an entire study area is important when estimating loads to be used as calibration data for regional water-quality models. PSLoadEsT is written using the open-source programming language R and has an easy-to-use interface written in Visual Basic for Applications ® within a Microsoft Access ® database file that guides the user through the necessary steps to estimate point source loads. The purpose of this report is to provide a detailed user guide for PSLoadEsT.

ProblemSediment is one of the most common causes of loss of stream-biologic integrity, whether in suspension in the water column, or as deposition on a stream or lake bottom. Fine-grained silts and clays are of particular concern because they can degrade habitat and often carry phosphorus and (or) other contaminants harmful to humans and aquatic life. Sediment-impaired water bodies, usually iden tified by fair to poor macroinvertebrate index scores, are placed on the 303(d) list of impaired waters, where a sedi ment Total Maximum Daily Load (TMDL) is developed under the Clean Water Act (https://www.epa.gov/tmdl). In order to effectively manage sediment, it is necessary to identify the sediment sources and locations of "hot spots" of erosion and deposition. Procedure manual now available for fingerprinting sources of sediment in streamsThe U.S. Geological Survey (USGS) and the U.S. Environmental Agency (EPA) recently published a manual on sediment source identification that includes details on how to conduct a sediment fingerprinting study (Gellis and others, 2016). This Fact Sheet summarizes key points in the sediment fingerprinting approach.