Bay and coastal beaches in Maryland and Delaware ranked among the cleanest in the nation in an annual survey released Wednesday by the Natural Resources Defense Council.
Only 3 percent of the Maryland water samples tested by local health authorities last summer for fecal bacteria, and 2 percent in Delaware, exceeded safe levels. That compares with 13 percent in the Great Lakes, 8 percent in New England, 6 percent in New York and New Jersey, and 7 percent nationally.
Overall, Maryland ranked seventh among the 30 coastal states for the smallest percentage of water samples exceeding safe bacteria levels. Delaware was second behind New Hampshire. Virginia was fourth.
Even so, the NRDC report said, wet weather last year triggered runoff and sewage spills that contributed to nearly three times as many beach closings and advisories in Maryland in 2009 as in 2008.
Several Chesapeake Bay beaches were singled out as the "dirtiest" of the 56 Maryland beaches included in the survey.
They were:
• Tolchester Estates Beach in Kent County, where 36 percent of the water samples tested by county health authorities exceeded safe levels of bacteria
•Red Point Beach in Cecil County, where 27 percent of the samples exceeded safe levels
•West View Shores, in Cecil County, where 17 percent of the samples exceeded safe bacteria levels
•Tolchester Marina and Beach, in Kent County, where 16 percent exceeded safe levels
•Bayside Beach, in Anne Arundel County, where 16 percent of the samples exceeded safe levels
Heather Morehead, beaches coordinator at the Maryland Department of the Environment, said some of the sampling at the beaches singled out by the NRDC followed heavy rain that boosted bacteria levels. Once-a-month sampling at those sites might also put too much weight on a few samples, she said.
Based on the locations and health department surveys, the bacteria at the sites are likely from wildlife or domestic animals, Morehead added.
Among Maryland's seven most popular beaches, four received four stars of a possible five. They were the East and South beaches at Sandy Point State Park, on the Chesapeake Bay in Anne Arundel County.
Assateague State Park and Ocean City's Beach 6, on the Atlantic, also received four stars, one fewer than in the 2008 NRDC report.
"We think they made an error," said Kathy Browhawn, chief of the Department of the Environment's public health section. The ocean beaches apparently lost a star because the NRDC believed water sampling there was done once a week.
"They sample twice a week," Browhawn said. "We're going to ask them to change it."
Delaware's Cape Henlopen State Park at Herring Point, and the Rehoboth Avenue Beach in Rehoboth, also received four stars, for the same reason. The nearest five-star beaches are in New Hampshire.
High fecal bacteria counts indicate the presence of potential pathogens from septic systems, surface runoff containing domestic animal or wildlife waste, or sewage spills. Water-borne illnesses can include rashes, pink eye, nausea, vomiting, intestinal distress, hepatitis and respiratory illness. The elderly, the very young and people with weakened immune systems can be especially vulnerable.
The federal Centers for Disease Control and Prevention has said the incidence of infections linked to recreational water use has increased steadily in recent decades.
The total number of days that Maryland beaches were closed, or swimming advisories were posted, more than doubled, from 61 days in 2008 to 133 days in 2009, an increase attributable to rainy weather, the report said.
But the 2009 total for Maryland was less than in 2006 and 2007. "In addition, there were no extended [more than six weeks] or permanent [more than 13 weeks] events in 2009 or 2008," the report noted.
Overall, the nation's beaches are far cleaner than in the 1980s, when discoveries of syringes and other medical waste on the sand became symbolic evidence of the contamination reaching U.S. shores, said David Beckman, director of the NRDC's water program.
In the 20 years that the environmental organization has been gathering state and local data on beach water quality, he said, more health authorities have begun regular monitoring and data collection and are closing beaches when contamination exceeds safe levels.
Even so, Beckman said, U.S. beaches "continue to suffer from serious pathogen contamination from human and animal waste." Such pollution "is preventable. We know how to stop it. Communities can tackle the most common sources of pollution."
Governments and individuals must replace outdated sewer systems, increase vegetation and permeable surfaces to slow and absorb runoff and "reverse the urban trend of capping the Earth in concrete," Beckman said.
Homeowners need to redirect drainage into gardens, maintain septic systems, and dispose of animal waste and motor oil properly, he said.
The NRDC has called on federal and state governments to tighten and enforce controls on pollution sources and to update water testing methods so results are available more quickly.