The Potomac River's split personality isn't doing its health any favors. From the increased development in exurban areas around Washington, DC, to a more intensive agriculture industry in the Shenandoah Valley, the health of the water quality is close to failing, according to the Potomac Conservancy.

The Conservancy, which calls itself the environmental voice of the nation's river, grades the river every five years. In its November 2011 report, it gave the Potomac a D - down from a D plus in 2007. The reason for the downgrade stemmed from increased impervious surface in the watershed, the loss of trees as buffers and the increased amount of animal waste connected to chicken farms, said Hedrick Belin, the conservancy's president. Buried streams, Belin said, are also a major source of pollution to waterways, and one area where researchers are only just learning the extent of the problem.

Of particular concern are counties like Loudoun, VA, which is one of the fastest-growing in the area and home to bustling Dulles Airport. Yet Loudoun is also home to productive, rolling farmland, a wine industry and a lot of land that has been conserved. A recent effort in the county to reduce the amount of development allowed in buffer areas was met with an outcry from residents and homeowners' associations.

Todd Lookingbill, a geography professor at the University of Richmond whose research was used in the conservancy's report, said many problems stemmed from the "super-commuting" culture around the D.C. area, where people drive ever-farther distances from home to work so they can afford a large house with a yard. It is not unusual to find people commuting two hours, from Fredericksburg - or even West Virginia - to downtown D.C. That has continued in Northern Virginia even during the recession, although the trend has lessened somewhat in western Maryland.

"One of the interesting findings, and also a troubling one, is that exurbanization is increasing, and it is coming to areas of attractive natural resources," Lookingbill said.

The conservancy has a plan of action so the river looks better when they re-evaluate it five years from now. It wants to hold state and federal officials accountable for enforcing the watershed implementation plans; work with counties and municipalities on environmentally beneficial practices that encourage narrower streets and fewer mandated parking spaces; and shore up support for stream buffers wherever possible.

"The good news is, we know what needs to be done to restore the Potomac so you can swim after a rainstorm and eat the fish you catch there," Belin said.