Water Quality Monitoring

The Washington region has a major interest in understanding water quality in local streams and rivers, the Potomac River and, ultimately, the Chesapeake Bay to gauge how effectively our multi-billion-dollar investment in water quality infrastructure is working. Investment in pollution reduction technology at wastewater plants, in advance treatment at drinking water facilities and in water quality controls in stormwater infrastructure is driven by regulations designed to ensure that these waters meet national standards for public and environmental health.

COG coordinates with state and local government officials, scientists from local universities, and other experts from around the region who collect and analyze water quality monitoring data from local waters. Their focus includes both data trends, useful for evaluating the effectiveness of management actions, and tracking of potential problem issues, such as summertime levels of harmful algal blooms. Through regular forums, COG staff communicates the results of this analysis to our members’ program managers and elected officials. The COG factsheet, Potomac Water Quality in the Washington Region, produced in 2014,  provides an overview of water quality in the Potomac Estuary, noting accomplishments and challenges.

Much of the water quality monitoring effort is centered on the upper Potomac River estuary, where most of the effluent from the region’s wastewater treatment facilities is discharged and where much of the stormflow from the region’s urban areas also impacts the river. These waters mix with the flow from the upper portion of the Potomac River watershed to largely determine water quality in the upper estuary.

Among COG’s partners in evaluating water quality monitoring data are:

Maryland Department of Natural Resources

Virginia Department of Environmental Quality

District Department of Environment

Occoquan Watershed Monitoring Laboratory

George Mason University

University of Maryland Center for Environmental Science

Potomac River Monitoring at Chain Bridge

At Chain Bridge, the river transitions from a  free-flowing stream to one influenced by tidal currents, making this fall line location a good spot from which to monitor the quality and quantity of upstream flows to the Potomac estuary. COG contracted with the Occoquan Watershed Monitoring Laboratory  in 1983 to establish an automated monitoring station  at Chain Bridge to gather data on the amounts of nutrients, sediment and other constituents flowing into the upper estuary. The station, which has been operated continuously since 1983, provides the most comprehensive fall line monitoring data in the entire Chesapeake Bay region. It also provides a check on the less comprehensive water quality monitoring protocol separately conducted by the U. S. Geological Survey at Chain Bridge for the Chesapeake Bay Program.

Data from the OWML’s Chain Bridge monitoring station is available at: http://www.owml.vt.edu/.