Demolition of the chromium-contaminated Allied Chemical Corp. buildings near Fells Point is almost half completed.
Allied-Signal Inc., the New Jersey-based owner of Maryland's biggest hazardous waste cleanup site, said that it expects all of the buildings to be torn down by next year and the $70 million cleanup to be finished by 1995.
John A. Turner, a spokesman for Allied, said Friday that it will take a crew of about 100 space-suited workers at least another year to dismantle the remaining parts of the chromium factory.
The workers must wear protective gear because of asbestos, which has been removed from most of the buildings, and chromium, which is a toxic heavy metal, he said.
In 1985, Allied shut down the plant -- site of the nation's first chemical chromium plant -- because the paint and leather-tanning markets for chromium dried up.
Chromium compounds were used to make yellow and green paints and to make leather supple. But substitutes were found after it was shown that chromium damages lungs and can cause cancer.
When the plant operated, it produced as much as 70 percent of all of Maryland's annual hazardous waste. And much of the chromium was dumped outside the buildings, where it began to leach into the ground, causing continuing pollution problem.
Mr. Turner said that the workers are taking the two-acre former sodium bichromate plant apart piece by piece, severing steel girders with blow torches and breaking up walls in order to decontaminate and recycle material as they go along.
Even though the most dramatic-looking work is being done now, Alvin Bowles, administrator of the state Department of the Environment's hazardous waste program, said that the most important part of the cleanup will have to wait until all the buildings are down.
Until the company installs an underground barrier and caps the 22-acre site -- at least three years from now -- about 62 pounds of chromium a day will leach from the contaminated soil into underground fresh water or the Chesapeake Bay, Mr. Bowles said.
Studies of the site show that chromium laces the soil as deep as 80 feet down, and it would be impossible to remove all the soil, Mr. Bowles said. So Allied will have to inject a special kind of clay underneath the contamination in order to create a kind of underground waterproof wall above the bedrock, he said.
"The idea is not to dig up the site. You can't dig up 85 feet of soil across 22 acres and ship it all to Ohio, even if Ohio would take it," he said.
Only after Allied places clay or concrete barriers under and on top of the contaminated ground will chromium pollution stop, he said.
Then the waterfront site, immediately west of Thames and Caroline streets, will be ready to be used again, Mr. Bowles said.
Though the site might have a stigma because of the years of chromium contamination, Mr. Bowles said that he believes that it will be a safe and attractive place for future development.
"There is a lot of speculation" about how it could be used, he said. Mr. Bowles noted, however, that any use will require state approval.
Allied's Mr. Turner said that he doubted that Allied itself would want to use the site.