Streamflow data are presented in columns as daily mean discharge (cubic feet
per second) beginning in 1985. Although water quality samples are collected at the Potomac River monitoring station at
Chain Bridge in Washington, D.C.,
discharge measurements cannot be made here due to heavy traffic and difficulties with access. The station used to
compute loads for this site, therefore, is the Potomac River near Washington, D.C., USGS station 01646500, 1.2 mi
upstream from Chain Bridge.