By David A. Fahrenthold
Washington Post Staff Writer
Tuesday, November 13, 2007
The Potomac River, celebrated for its comeback from abysmal pollution, is still seriously fouled by contaminants that wash down from farms and fast-expanding Washington suburbs, according to a report from an environmental group.
The Potomac Conservancy, a Silver Spring-based nonprofit group, gives the river a grade of D-plus in its first "State of the Nation's River" report. The report is to be formally unveiled this morning.
The report comes as federal scientists say that more "intersex" fish, showing elements of both genders, are being found in the river. Previous studies had shown that male bass in District waters were growing eggs; new data show that female fish also seem to be developing abnormally, one researcher said yesterday.
The Potomac Conservancy's report cites the intersex problem -- along with high levels of dirt, sewage and other pollutants -- to show that the Potomac might be in danger of backsliding after a decades-long rehabilitation.
"We've plateaued," said Hedrick Belin, president of the conservancy, which has pushed for cleaner water and the protection of land along the Potomac's banks. "The improvements that we've made, the progress, has stalled out."
Overall, the Potomac remains an astounding story of revitalization. In 1965, after centuries of contamination by raw sewage and industrial pollutants, President Lyndon B. Johnson (D) called it a "national disgrace."
Since then, there have been large-scale improvements at wastewater treatment plants, and the Potomac is now clean enough to support numerous bald eagles and a famous stock of smallmouth and largemouth bass.
The cleanup "took a sewer and made a world-class fishery," said Ken Penrod, a longtime fishing guide. "Looking at it now, [compared with] 1960, I still have to smile."
But this success is now undermined by a combination of agricultural pollution and suburban sprawl, the Potomac Conservancy's report says.
Upstream, in such places as Virginia's Shenandoah River valley, manure from large chicken farms and other agriculture washes downstream to the Potomac, carrying bacteria and pollutants that feed huge algae blooms.
In the Washington area, the report says, development is replacing forests with streets, homes and shopping centers. In those places, rainwater, unfiltered by plant roots and soil, rushes into storm drains, carrying large amounts of grease, oil and silt.
The report says it took more than 200 years, from the arrival of European colonists to 1986, to cover 12.2 percent of the Washington area with concrete and other impermeable surfaces. Then, from 1986 to 2000, the proportion jumped to nearly 18 percent.
"More people means more rooftops and more roads," said Belin, of the Potomac Conservancy. And that, he said, "leads to greater contaminated runoff, coming off those hard surfaces."
The intersex fish are one of the river's least-understood problems. Possible causes include chemical pesticides, animal hormones in manure or human hormones in treated sewage. Something seems to be confusing natural chemical signals in the fish.
Now, in addition to the problems in male fish, females caught near the Blue Plains sewage treatment plant in Southwest Washington have been found with what seem to be abnormally low levels of estrogen, researcher Vicki Blazer said.
Fish in that area of the Potomac "are definitely messed up," said Blazer, a scientist at the U.S. Geological Survey.