The dredging of the Miami River, scheduled to begin this month, has been pushed back until at least the fall. However, the project, which has crawled through decades of studies and on-and-off political negotiations, seems to have cleared one of its last and biggest hurdles. Open air drying of sediment in a parking lot next to Miami Jai-Alai is no longer an opion.
Bending to objections from Miami-Dade County commissioners, the U.S. Army Corps of Engineers said that it has pulled that option off the table for the half-million cubic yards of contaminated slime that will be scraped from 5 miles of river bottom.
''We will not allow any open-air drying,'' Jerry Scarborough, the Corps' Miami River project manager, told the Miami River Commission on Monday.
Last May, when the Corps first outlined potential disposal plans, several commissioners were critical, saying they feared the muck might draw bird flocks, threatening flights from nearby Miami International Airport, and raise foul odors, offending neighbors and tourists.
While the Corps has not decided on how the stuff will be handled, Scarborough said it will add restrictions to its bidding proposal to keep the sludge under wraps or a roof.
''I think it was more a perception problem than a factual one, but since they were concerned about it, we took the necessary steps to alleviate their concerns,'' Scarbourough said. His agency's environmental experts had argued the muck did not pose any bird or odor problems.
In the interest of exploring potentially promising approaches, Scarborough said the Corps will not spell out to contractors any particular method to tackle the muck that has accumulated in the river since the 1930s. The dredging will deepen the river's channel to 15 feet from an average of 13, opening the way for larger freighters and a hoped-for economic and social revitalization.
There are a number of possible options -- from drying the sludge in ''geotubes'' that resemble giant sausages to pumping the stuff into freight cars and hauling it away. While the sludge is not ''toxic,'' it's highly tainted by sewage and industrial pollution -- lead, mercury and assorted other heavy metals, not to mention rusting appliances and animal bones -- and has to be disposed of in special landfills.
Open-air drying would have meant pumping the stuff under North River Drive, then drying it behind a grassy, fenced dike in an eight-acre parking lot about a half-mile from the airport's eastern boundary. That process could have taken an estimated five years, because there's so much material.
Roman Gastesi Jr., Miami-Dade's water resources manager, said he was pleased with the Corps' flexibility and hopeful the decision would ease public and commission concerns.
''There are processes that don't expose the stuff to air at all,'' Gastesi said.
Ironing out the disposal concerns already has pushed the dredging back several months, and there could be more delays.
Miami-Dade and the Corps also have to sign a project cooperation agreement, which cements the deal's details. The job could cost $60 million or more, and the federal government is picking up 80 percent. The state, through direct payments or rebates, is footing 15 percent. Miami-Dade and Miami are splitting the remaining 5 percent, excluding land purchases and leases.
Scarborough said the Corps hopes to have its dredging bidding proposal ready by April, with a final method picked by June. Actual work could start as early fall, he said, if other negotiations over land purchases and the movement of various utility lines in the river continue on schedule.