The National Aquarium unveiled plans today for a waterfront park along a contaminated shore of the Middle Branch of the Patapsco River, saying the $5.4 million project could help revitalize the blighted area of South Baltimore.

Mayor Stephanie Rawlings-Blake joined aquarium officials and Shawn Garvin, regional administrator of the Environmental Protection Agency, in a ceremonial seeding of the seven-acre strip of bare earth where the park is planned once work is completed capping the contaminated soil that lies beneath.

"The aquarium was involved with the revitalization of the Inner Harbor in the 1970s," noted David Pittenger, head of the downtown nonprofit that is the city's top tourist attraction. Rawlings-Blake said she hopes the aqaurium "will perform similar miracles with South Baltimore."

The aquarium acquired the 20-acre Middle Branch tract four years ago from the city for a new Center for Aquatic Life and Conservation it planned to build there. Construction of the center has been shelved until the economy improves, aquarium executives say, but the cleanup and park development are going forward.

The waterfront site, created years ago by dumping construction and demolition debris in a shallow area of the river, is a former city garage and vehicle yard that is contaminated with heavy metals and a variety of other toxic chemicals. The aquarium contracted with Potts & Callahan to remove 7,500 tons of debris and hazardous dirt, and to "cap" the ground with a layer of clean dirt before developing the park.

The EPA awarded a $200,000 "brownfields" cleanup grant to the aquarium for the project. The remainder is being funded with proceeds from the aquarium's sale of an eight-acre portion of the site to developer Patrick Turner for $8.3 million, said Timothy Pula, the aquarium's senior director of capital planning and facilities.

The park, which is to include walking and biking trails, a pier and overlooks, is slated to be completed by next spring.