Overseeing the Water Resources of Loudoun County, VA
STREAM ASSESSMENT
Every two years the Virginia Department of Environmental Quality (DEQ) conducts water quality assessments. Stream monitoring results are compared to numerical water quality standards to determine if the water quality "measures up", for example, if it is clean enough for swimming, fishing and other uses. If water quality falls below a certain level of cleanliness, DEQ identifies the location, the parameter of concern (such as high bacteria counts) and the likely sources (such as failing septic systems or animal in the creeks). The streams that do not meet Virginia Water Quality Standards are listed in a widely circulated pair of reports called the 305(b) and 303(d) reports. Since 2004, DEQ has combined both the 305(b) Water Quality Assessment and the 303(d) Report on Impaired Waters into the Virginia Water Quality Assessment 305(b)/303(d) Integrated Report.More recently DEQ has termed those waters not meeting the standards as "dirty water" and designates these as "impaired". A stream is "impaired" when the reach is determined to be "Not Supporting" for the designated use.
"Not Supporting Designated Use" --> "Impaired" --> "Dirty"
Once listed, the stream segment is typically scheduled to have a TMDL report prepared, which is often tewlve years into the future. The TMDL report identifies the sources of the pollution and how much the sources need to be reduced to get the stream off of the "dirty waters" list. But first a TMDL Implementation Plan needs to be writtend and the implementation, or restoration activities, needs to be funded and take place.
More information may be found on-line at: http://www.deq.state.va.us/wqa/.
info@loudounwatershedwatch.org Copyright © 2011 Loudoun Watershed Watch