Primary homepage for the National Water Quality Assessment (NAWQA) Program studying water quality in river, aquifer and coastal water basins throughout the nation. Links to reports, data, models, maps and national synthesis studies.
Homepage of the Office of Water Quality programs on the quality of the Nation's surface water and ground water resources, with links to general information, quality assurance, software, data, publications, USGS facilities, techniques, and programs.
Homepage for USGS water quality information. The NWISWeb discrete sample database is a compilation of over 3.5 million historical water quality analyses in the USGS district databases. Also includes access to real-time data and a tutorial.
Homepage for the Toxic Substances Hydrology Program, which provides scientific information on contaminated sites and on human and environmental health. Links to news, topical information, investigations, meetings, publications, and photos.
Detailed information on Total Maximum Daily Load, the total quantity of a pollutant that a stream can carry and still conform to water quality standards, used as a measurement in the monitoring, assessment, and remediation of polluted waters.
A brief definition and explanation of hypoxia with special reference to the Gulf of Mexico hypoxic zone along the Louisiana-Texas coast as well as extensive links to USGS and other related information resources.
Overview of the Toxic Substances Hydrology Program role in investigating the occurrence and fate of agricultural chemicals with links to investigations, headlines, on-line fact sheets, new publications, bibliographies and photo gallery.
Cooperative national project with the Federal Highway Administration (FHWA) to evaluate FHWA's guidelines for highway-runoff quality. Links to searchable online bibliography of related publications by the USGS, EPA, FHWA, and state agencies.