About 1,100 miles of Virginia's rivers and streams have been added to the state's list of polluted waters in the last two years, bringing the total to 10,600 miles, state environmental regulators said in June.
The state Department of Environmental Quality released its 2008 water quality report, which listed about 40 percent of the state's waters as polluted. All of the major rivers, as well as the Chesapeake Bay, had "some impairment," DEQ spokesman Bill Hayden said.
"That number keeps getting larger, mainly because as we look around the state more thoroughly, we find more," he said.
About one-third of Virginia's watersheds are assessed every two years. The agency has analyzed 95 percent of Virginia's watersheds.
The agency said the state's polluted waters-which include rivers, lakes and estuaries-require a total of 1,677 cleanup plans, known as Total Maximum Daily Loads. Hayden said only a couple of hundred have been developed.
The DEQ also added 3,300 acres of lakes to the impaired list, bringing the total in that category to 94,000 acres. In addition, 2,200 square miles of estuaries are listed as impaired.
The DEQ said more than half of the new listings were polluted by excess bacteria. Low-oxygen levels accounted for 18 percent of the listings.
Hayden said 105 waters were removed in the 2008 assessment, all of them streams that feed into major rivers including the James, Potomac, Shenandoah, Rappahannock and Roanoke.
In some cases, streams were removed because conditions such as low oxygen were found to be their normal state rather than the result of pollution.
Cleanup plans accounted for other removals, Hayden said.