For at least 60 years, a man-made ditch at the Sparrows Point steel mill carried stormwater and polluted discharge from steelmaking operations across the vast property.
Known as the Tin Mill Canal, it was once filled with murky water that deposited contaminants in the soil around it.
The canal represents one of the biggest environmental challenges for Tradepoint Atlantic, the company that bought the old mill and is turning the site into an industrial campus. Company officials say the canal will flow through a new retail center on the property.
Since January, contractors have been gradually removing the contaminated soil and re-lining the canal bed. On Wednesday,...