Specific conductance at 25 degrees Celsius
Overview
Specific conductance is a measure of the capacity of water to conduct an electrical current and is a function of the types and quantities of dissolved ions in water. As concentrations of dissolved ions increase, specific conductance of the water increases. Temperature also strongly affects the electrical conductivity of water; specific conductance compensates for this by normalizing measurements to what they likely would be if the water were 25 degrees Celsius.
Water-quality standards and criteria are developed by the States, approved by the U.S. Environmental Protection Agency (USEPA), and then promulgated (passed into law) as standards by each State. Graphs on this website allow comparison of measured and computed data to these standards and criteria by plotting them as straight lines. When evaluating data to decide whether water quality is suitable for the intended use, viewers are cautioned to consider the uncertainty associated with these computed data.
Water-quality Standards and Criteria
Anacostia River likely road-salt effect threshold: 400 uS/cm
Unusually high SC values in the winter are caused by road salt washoff. It has been proposed that, during winter months, 400 microsiemens per centimeter is a likely maximum SC value for non-road-salt conditions. Although not truly a water-quality standard or criterion, this value is shown for general reference.
Source: Miller and others, 2007 (view online)
Stations That Measure or Compute Continuous Specific conductance at 25 degrees Celsius
Click a station to view measurements of specific conductance at 25 degrees Celsius.