Cleanup crews have recovered most of the free-floating oil that spilled into the Patuxent River and its tributaries April 7 from a Prince George's County power plant, but an oily sheen remains visible on the surface and congealed tar balls may surface with warmer weather.
State and federal environmental officials said yesterday that they had recovered 24,000 of the 111,000 gallons of oil that spilled from a broken pipeline at the Potomac Electric Power Co. plant at Chalk Point. They also recovered an undetermined amount of oil in 975,000 pounds of absorbent material, containment booms, blankets, netting and protected clothing.
An estimated 30 percent of the oil soaked into a 45-acre marsh at the head of Swanson Creek on PEPCO's property, but large quantities were blown over containment booms and into the Patuxent during a storm April 8. At one point, the oil plume stretched 17 miles along the river, fouling some 20 miles of shoreline.
The cleanup effort has intensified in Swanson Creek and the marsh while other crews are working in creeks on both sides of the river.
The state Department of the Environment has closed shellfish beds in the area and warned residents not to harvest fish and crabs. Officials also warned against using beaches and shorelines where oil is visible.
The main channel of the river is open to boating, though boaters should proceed cautiously between Chalk Point and the Thomas Johnson Bridge near the mouth of the river to avoid interfering with cleanup crews. Some tributaries remain closed while crews are working. Boaters who try to jump the containment booms risk fines of up to $25,000.
The U.S. Fish and Wildlife Service said the oil has killed 52 birds, 44 mammals -- mostly otters and muskrats -- and four reptiles. Residents who find dead or oil-fouled birds and animals should call the service at 301-579-6098.