The former director of the state Air Resources Division last night challenged the current head to buck the law, if need be, when considering whether to approve a permit to allow construction of a $457 million upgrade to a coal-fired power plant in Bow.

The Legislature in 2006 passed a law requiring Public Service of New Hampshire to install a scrubber to capture mercury emissions. The cost of the project has jumped 83 percent since then.

Ken Colburn, who led the division for about five years until 2002, lauded the division staff for advancing pollution control in the state.

But, he said, "the fact that something's technologically possible doesn't make it the wisest course forward."

The division staff heard mostly from people who oppose the installation of the scrubber last night at a hearing where about 100 people attended but only about 15 spoke.

Lawmakers resoundingly approved the mercury reduction law, which would require a scrubber to capture 80 percent of mercury contained in the coal that is burned at the plant. Two years later, the law is being challenged in court and before the Legislature by people who think the money could be better spent in energy efficiency and renewable energy production.

Last night's hearing was supposed to focus on the terms of the construction permit and whether the project complies with emissions laws, but it was the first opportunity the public has had to comment on the project since the price increase.

Colburn is working with a group of commercial ratepayers challenging the scrubber. He said mercury controls at most plants cost less than $25 million.

He challenged the division staff to do as they did in the late 1990s when they defied a costly order from the federal government to conduct tailpipe testing on cars to control volatile organic compounds. At that time, the latest science had shown that nitrous oxides should have been regulated instead. He said the division has a "broader mandate" to protect citizens' interests.

Bob Scott, the current Air Resources director, said the tailpipe testing was a different issue. That was a federal mandate, and the state worked with federal regulators to come up with an alternative. The mandate to install the scrubber comes from state lawmakers.

"My job is to follow state law," Scott said after the hearing.

State Rep. Mary Beth Walz, a Democrat from Bow, said she supported the bill in 2006 and liked that it brought PSNH, lawmakers and environmentalists together to come up with the best plan.

"The Legislature determined that this was in the public interest," she said, in her testimony. "I have not heard anything here tonight that suggests that it would not still be in the public interest."

Last year, PSNH upgraded one of its turbines to produce more power with the same amount of coal. The added power would be used, at least in part, to offset the power that it takes to run the scrubber.

Melissa Hoffer of the Conservation Law Foundation said the company violated state and federal laws by doing that work before the Air Resources Division issued a permit for construction. She said the company has apparently grouped the cost of the turbine upgrade into the scrubber cost, and the law requires permitting to be grouped together as well.

Single page