The USGS operates a network of real-time water-quality monitoring stations that measure up to five physical parameters. The parameters are temperature, specific conductance, pH, dissolved oxygen, and turbidity. One to four of those parameters are measured at 26 sites, while all five parameters are measured at 13 sites. These data are used for decision making about hydroelectric power generation, water treatment, regulatory programs, recreation and resource monitoring, healthy ecosystems, and public safety.