Contract sent to Sher Garner firm for completion, despite objections from some City Council members.
Groups opposed to the project say construction could damage what they say is a historically significant site, possibly containing graves of enslaved people from nearby plantations.
The remaining residents of the subdivision have been fighting for relocation funding for years.
The proposed consent decree would settle a suit filed by environmental organizations and a group of residents of St. John the Baptist Parish.
The plaintiffs seek to stop the construction of the grain elevator, alleging that the site likely contains unmarked graves of enslaved people from nearby plantations.