While the Chesapeake Bay's overall health improved slightly last year, the rivers that drain much of the Baltimore area remain in such poor shape that they earn a "failing grade," University of Maryland scientists reported Tuesday.
The bay as a whole improved its overall grade from a C-minus to a C on the annual report card prepared by the University of Maryland Center for Environmental Science.
Eight of the bay's major rivers systems in Maryland and Virginia had at least marginally better conditions for fish and crabs last year, while four remained unchanged. But two tributaries, the Baltimore-area's Patapsco and Back rivers, bucked the trend and actually worsened.
The two rivers, which empty into the bay around Baltimore harbor, continued to register the worst conditions among all the Chesapeake's tributaries, rating the only "F" on the report card for the second straight year.
Gov. Martin O'Malley released the bay report card at Gunpowder Falls State Park in Baltimore County, along the healthiest stretch of the Chesapeake, which includes the Gunpowder, Bird and Susquehanna rivers. He said the report card provided a "glimmer of hope" for the bay.
But he cautioned: "We still have a lot to do to get her off life support and get her walking again."
The Patapsco and Back rivers, in particular, need help because they are in the most dire situation, said William C. Dennison, vice president of the environmental science center and the coordinator of the bay health report card. "That's going to be the heaviest lifting we have in the whole [bay] watershed."
Occupying just 1 percent of the bay's 64,000-square-mile watershed, the Patapsco and Back rivers drain one of its most densely developed and populated areas. There are nearly 1.5 million people living in the 630-square-mile drainage basin encompassing Baltimore city and portions of Anne Arundel, Baltimore, Carroll and Howard counties. There also are seven major sewage treatment plants that discharge into the rivers.
Some help is on the way.
The Back River sewage treatment plant — the region's largest — is due for an overhaul to increase its ability to remove harmful nitrogen and phosphorus from wastewater before they can spur algae growths that starve water of the oxygen needed by fish and crabs. The $460 million "enhanced nutrient removal" project is slated to begin in November and be finished by January 2016, according to Jay Apperson, spokesman for the Maryland Department of the Environment.
But Dennison said much more is needed. He noted that most streams and creeks that drain into the Patapsco and Back rivers are in poor or very poor condition, with portions of many actually buried under streets and parking lots. While water clarity improved by an average of 12 percent baywide, it didn't improve at all in the Baltimore area rivers, which are so murky they've scored a zero for clarity over the past decade.
Even so, the bay scientist said, "I don't think it's terminal. I think there is potential."
The factories that once pumped toxic pollution into the harbor and the area's rivers are gone or have largely cleaned up, Dennison said, though hazardous metals and chemicals from that era still linger in sediments that will have to be dealt with.
To make the rivers more habitable for fish, he said, the city and surrounding counties need to break up acres of pavement and revamp an aging network of storm drains that wash pollution into the streams every time it rains.
"We need to daylight some of those buried streams and to get more green roofs and rain gardens in that urban footprint," Dennison said. He said that posed a costly challenge for the region.
South of Baltimore, the rivers that drain the rest of Anne Arundel County are in a little better shape, but face different challenges, Dennison said.
The upper reaches of those rivers appear to be improving, as sewage treatment plants get upgraded to curtail nutrient pollution, he said. But the lower stretches nearest the bay are actually declining, he said, as as more "McMansions" get built along the waterfront, with fertilized lawns to the water's edge and bulkheads or rip-rap making the shore inhospitable to wildlife.
"When you're on the water … it's really remarkable how much of the shoreline is hardened and how much is populated by large houses or condos that are in large part on septic systems, which even on advanced technology are never going to be as good as sewage treatment."