US Environmental Protection Agency BASINS metadata reports -
"This dataset describes the accumulation of chemical contaminants in river, lake, ocean, and estuary bottoms and includes a screening assessment of the potential for associated adverse effects on human and environmental health. EPA evaluated more than 21,000 sampling stations nationwide using sediment chemistry data, chemical residue levels in edible tissue of aquatic organisms, and sediment toxicity data. Of the sampling stations evaluated, 5,521 stations were classified as Tier 1 (associated adverse effects are probable), 10,401 stations were classified as Tier 2 (associated adverse effects are possible, but expected infrequently), and 5,174 stations were classified as Tier 3 (no indication of associated adverse effects). Ninety-six watersheds were identified as areas of probable concern for sediment contamination. EPA believes that these watersheds represent the highest priority for further ecotoxicological assessments, risk analysis, temporal and spatial trend assessments, contaminant source evaluation, and management action because of the preponderance of evidence in these areas (although further evaluation is necessary). Also see the related report entitled The Incidence And Severity Of Sediment Contamination In Surface Waters of the United States, Volume 1, National Sediment Quality Survey (EPA 823-R-97-006, <http://www.epa.gov/OST>) that was published in September 1997. For distribution with BASINS v.2.0, the spatial attributes of the database were prepared in Arcview shape file format while selected relational attributes were prepared in Arcview DBF file format." "This data set provides individuals with observation level data that were used in the most geographically extensive investigation of sediment contamination ever performed in the United States. Based on this evaluation, sediment contamination exists at levels where associated adverse effects are probable in some locations within each State of the country."
"The U.S. Environmental Protection Agency prepared these data and the related assessment to meet the requirements set forth in the Water Resources Development Act (WRDA) of 1992, which directed EPA, in consultation with the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Army Corps of Engineers (USACE), to conduct a comprehensive national survey of data regarding the quality of aquatic sediments in the United States. The Act required EPA to compile all existing information on the quantity, chemical and physical composition, and geographic location of pollutants in aquatic sediment."
US Environmental Protection Agency BASINS metadata reports -
"The National Sediment Quality Survey is a screening-level assessment of sediment quality that compiles and evaluates sediment chemistry data and related biological data taken from existing databases. The data and information contained in this document could be used in various EPA regulatory programs for priority setting or other purposes after further evaluation for program-specific criteria. However, there is no immediate or direct regulatory consequence. This evaluation does not in itself establish any legally binding requirements, establish or affect legal rights or obligations, or represent a determination of any party's liability."
CREDIT Please acknowledge USEPA. The data was developed by the U.S. Environmental Protection Agencty as part of BASINS 3.0
"Version 1.2 of the data contains only the data evaluated as part of the National Sediment Quality Survey and the results of the screening level assessment. Earlier versions (e.g., 1.0 and 1.1) contain additional data quality information as available in original data sources. Other information such as grain size, lipid content, etc. and chemicals not evaluated as part of the NSI are also available in earlier versions of the data, but are not part of the data extracted for BASINS."
"The data were directly extracted from the source data files located on the EPA IBM mainframe, located in Raleigh, North Carolina. Using basic SAS commands, the files were converted directly to DBASE formatted files for transporting into this application. The geographic coordinates for sampling stations were obtained from the source data. Since most of these stations have existed for some time, it is likely they were determined by using USGS 1:24,000 - 1:100,000-scale topographic map (depending on map availability), which is consistent with the approach used for many EPA data systems originally developed in the early 1980's."