ROCKLAND — A stark and dark cloud of black particulates settled over Rockland Harbor just after 5 p.m. July 22; its source, the FMC smokestack on Crockett’s Point.

Marc Cone, director of the air bureau at the Maine Department of Environmental Protection, said Wednesday morning, July 23, that his agency would be following up with FCM Corporation to determine what the cause was.

Barbara Delduke, FMC spokesperson based at corporate headquarters in Philadelphia, said the smoke was released during a “failure in the boiler area.”

The plant currently burns No. 6 fuel oil but is converting to compressed natural gas.

“It was brought under control very quickly,” she said. “There was no fire, nor was the air quality deemed unsafe at any time.”

She said the emissions were “nonhazardous.”

Delduke said she would be providing more information about the incident, and contact information for boat owners affected by the soot, as the investigation continued.

Louis Fontaine, who is also with the DEP’s air bureau, said Wednesday that no complaints have been received about the incident; however, a DEP investigator has now been assigned to the case.

He said FMC does hold an air emissions license from the state.

FMC Rockland Maine has been home since 1936 of one of the world’s leading seaweed-based businesse, according to the company. The FMC BioPolymer plant produces carrageenan, derived from seaweed, to provide innovative applications for global food processors. The products meet demanding texture requirements and multiple other applications, such as binding agents for toothpaste.

One FMC employee said Wednesday morning that the plant is converting its energy system to compressed natural gas and that there will be no more discharges from the stack.

“We will follow up with the company to find out what the heck was the going on,” said Cone, at the DEP.

Tim Woodworth, of Rockland, said his boat lay directly beneath the soot cloud. His son, Paul, was working on the Rockland waterfront and captured the black cloud on camera, sending the photo to his father.

Tim said he went to the harbor 30 minutes later and the smoke was gone, but a brown discharge continued to emit from the stack.

The deck of his sailboat was covered with soot.

“It’s not bad but it’s a bad thing to be breathing,” he said.

The discharge was visible for miles, as witnesses wondered if there was a fire in the area.

This story will be updated when more details become available.

Editorial Director Lynda Clancy can be reached at lyndaclancy@penbaypilot.com; 207-706-6657.