PORTSMOUTH, N.H. (AP) – The president of Public Service Company of New Hampshire says new mercury pollution standards could force the state’s largest electric utility to close its coal-burning power plant in Bow.

President Gary Long said Public Service is trying to cut mercury emissions, but the standards set by Senate Bill 128 are impossible to meet.

The bill would require Public Service to cut mercury pollution at Merrimack Station in Bow and Schiller Station in Portsmouth from a combined total of 120 pounds per year to 50 pounds by 2009 and 24 pounds in 2013. Public Service would not be allowed to meet the requirements by using pollution credits.

The bill passed the Senate last month and is now in the House.

Long said the company cannot cut its mercury emissions that much, that quickly. He said the utility is working to meet less-strict federal guidelines to reduce mercury emissions to 50 pounds by 2018.

“It’s the state’s timeline that seems so radical to us,” Long told the Portsmouth Herald. “I don’t know how to comply with it.”

State environmental officials disputed that.

“The 2009 and 2013 deadlines are consistent with what neighboring states are doing,” said Jeff Underhill, chief scientist with the DES Air Resource Division.

Long said Public Service will test a carbon injection system to remove mercury from its emissions at Merrimack Station this summer. If that fails to bring down mercury levels enough, Public Service could install a scrubber system to cleanse the coal at an initial cost of $200 million and annual operating cost of $30 million, leading to a rate hike of 4 or 5 percent.

Long said it was unclear whether those measures would reduce mercury emissions enough.

“We might just run the (Bow) plant until the rule takes effect and shut it down,” he said.

But Underhill said the technology works well.

“Other facilities have had good luck with this,” he said. “There’s a facility in Georgia that installed a carbon injection system and they achieved an 80 percent reduction.”

Mercury is a toxic heavy metal that builds up in the fatty tissues of fish and animals, including humans. It can cause neurological damage and serious birth defects at higher levels.

AP-ES-04-09-05 1304EDT