SALEM — Salem Harbor Station released the third highest amount of toxic chemicals in the state in 2007, according to a report released yesterday by the Environmental Protection Agency.
The power plant, which burns coal and oil, generated 276,492 pounds of chemicals in 2007, the most recent year for which statistics are available, according to the agency's Toxic Release Inventory data.
That figure, however, represents a significant decrease from prior years.
The top polluter was the Brayton Point power plant in Somerset, which released 1.7 million pounds. Both plants are owned and operated by Dominion Energy of Virginia.
The Mount Tom generating station in Holyoke ranked second at 489,104 pounds.
"I'm disappointed but not surprised," said Jane Bright of HealthLink, a North Shore environmental group. "... The top three (polluters) in the state are coal burners, which just tells you how filthy and dangerous coal is."
Although the Salem plant ranks high, the total amount of chemicals released on and off the site has dropped significantly in the past few years.
Salem released 369,065 pounds of toxic chemicals in 2006 and 550,358 pounds the year before.
The drop in 2007 is due primarily to the plant switching to low-sulfur coal, an official said. The plant also was closed for almost two months that year after a fatal accident.
The toxic release inventory covers chemicals released to the air, water and land by power plants, manufacturers and other facilities. It does not include sulfur dioxide and nitrogen oxides, two pollutants that cause soot and smog.
The two main chemicals released in Salem were ammonia and barium compounds, the EPA said.
Overall, the release of pollutants decreased in Massachusetts from 2006, the EPA said. In 2007, 513 facilities reported 6.5 million pounds of chemicals, a drop of about 365,000 pounds.
About 65 percent of the chemicals released in Massachusetts were to the air, according to the EPA.