Construction on the south terminal began last week after officials had to cancel the official ground-breaking at the site due to the Boston marathon bombings.

The Massachusetts Clean Energy Center says it has chosen Quincy-based contractor Cashman-Weeks to construct the marine commerce terminal and perform the associated dredging. As part of construction, the project includes the dredging and removal of approximately 250,000 cubic yards of contaminated sediment, and the bulkhead will be able to support an average of 4,100 pounds per square foot.

Center spokeswoman Catherine Williams says despite the cancellation of the ground-breaking ceremony, Cashman-Weeks and Masscec signed the "notice to proceed" April 16 that authorized work to begin on site. The contractor was one of three that submitted bids for the project in February. It submitted the lowest base bid of $56.9 million.