A new online data warehouse of 6.5 million records enables water resource managers, scientists, and the public to find data about the quality of the water at 2,800 stream sites and 5,000 wells in 46 states, according to the U.S. Geological Survey.

The data were collected by the USGS National Water-Quality Assessment (NAWQA) Program beginning in 1991 in 36 basins around the country, which are the basic study units (http://water.usgs.gov/nawqa/) of the NAWQA effort. The data warehouse has been in use by USGS researchers since November 1999. Data from 15 additional study units, which began in 1997, will be incorporated later.

Data in the warehouse are from surface and ground water sources, not from finished tap water.

The data include about 15,000 pesticide and VOC (volatile organic compound) samples and about 26,000 nutrient samples collected from the water column, as well as about 1,200 samples from bed sediment and aquatic animal tissue, which were analyzed for trace elements and organic compounds that do not dissolve in water easily.

Most pesticide, sediment and tissue samples were analyzed for over 40 different compounds at the USGS National Water Quality Laboratory in Denver, Colo.

Types of information include:

· Site, well and network (groups of sites with similar characteristics or sampling regime) information and descriptive variables like land use.

· Daily streamflow and temperature information for repeated sampling sites.

· Chemical concentrations in water, sediment and aquatic organisms.

Data can be compiled and summarized for geographic areas, such as for one or multiple states, counties, basins, or NAWQA study units. Examples of summaries include:

· Concentrations for groups of chemicals, like pesticides, detected in streams, streambed sediment/aquatic tissue and/or wells.

· Samples where the concentration of a specific chemical of your interest exceeds some value like a water quality standard.

· Counts of samples for one of the above examples.

The data can be easily exported in several formats to excel, or delimited ascii files.

Links are provided to other data from the NAWQA program, other water data from the USGS, as well as to the USGS home page, which provides a gateway to a wide range of scientific information from the biology, mapping and geology components of the USGS.

As the nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to the sound conservation, economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy and mineral resources.