On April 4, 2017, the U.S. Geological Survey (USGS) announced the release of a new interactive mapper tool to show data from 40 years of water-quality monitoring, including from the National Water Quality Assessment program (NAWQA). The mapper is available online at https://nawqatrends.wim.usgs.gov/swtrends/.
According to the mapper’s Web site, the tool shows stream trends in water chemistry and aquatic ecology (fish, invertebrates, and algae) for four time periods: 1972-2012, 1982-2012, 1992-2012, and 2002-2012.
Following is an excerpt from the USGS news release on the tool: “For the first time, monitoring data collected by the USGS and 73 other organizations at almost 1,400 sites have been combined to provide a nationwide look at changes in the quality of our rivers and streams between the 1972 passage of the Clean Water Act and 2012. …The interactive map can be used to see whether 51 water-quality constituents, like nutrients and pesticides, and 38 aquatic-life metrics, like the types and numbers of fish, macroinvertebrates, and algae, have increased, decreased, or remained the same at nearly 1,400 sites between 1972 and 2012. …The map summarizes the first phase of the study—in which the USGS identifies streams that have been monitored consistently for long periods and reports the trends in those streams. In the second phase, to take place over the next several years, the USGS will assess whether and where billions in investments in pollution control have been effective, identify major causes of trends in U.S. stream quality, provide details on which chemicals are increasing or decreasing, and highlight whether any drinking water sources or aquatic ecosystems are at increased risk.”
Source: First-of-its-kind Interactive Map Brings Together 40 Years of Water-Quality Data, U.S. Geological Survey News Release, 4/4/17.