The Department of Labor's Occupational Safety and Health Administration has proposed a $1.3 million penalty for Atlantic Coast Utilities, the company in charge of the work site in Boston's Financial District where two workers were killed in February when they were struck by a dump truck and knocked into a trench.

The fines follow OSHA's six-month investigation into the worksite along High Street. The agency cited the Wayland-based company and its predecessor companies for 28 willful, repeat violations, including refusal to train workers "to recognize and avoid work-related hazards."

The company's owner, Laurence Moloney, is a "serial violator" with an "extensive history" of health and safety violations that spans from the early 2000s, OSHA officials said. He currently owes the department about $73,000 in unpaid fines through other, predecessor companies.

Moloney now has 15 businesses days to either pay, or contest the fines, or request an informal conference with OSHA.

"Given the severity and nature of the recent hazards, and Atlantic Coast Utilities LLC/Advanced Utilities Inc. and its predecessor company’s history of violations, OSHA used its egregious citation policy, which allows the agency to propose a separate penalty for each instance of a violation," the agency said in a press release.

Speaking to reporters Wednesday, Christine Eskilson, Labor Department Deputy Regional Solicitor for the New England area said while the department can hold successor companies responsible for the fines of its predecessors, the agency "can't prevent someone from incorporating a new business," as they allege Moloney has done for more than two decades.

"We just keep tracking them down," Eskilson said.

OSHA has now also opened a separate inspection of an East Boston worksite affiliated with one of Moloney's other companies, Sterling Excavation LLC.

In addition to the fines, the Labor Department's Wage and Hour division is now currently investigating Atlantic Coast Utilities for potential violations of federal wage law.

Moloney did not respond to GBH News requests for comment Wednesday.