The debate over burning trees for electricity is heating up again as a wood-fueled power plant moves closer to construction in Fair Haven. The Vermont Department of Environmental Conservation issued an air quality permit last week to Massachusetts-based Beaver Wood Energy to construct a biomass generation plant and accompanying wood pellet manufacturing facility in a part of Vermont that already suffers from the highest asthma rates in the nation.

Vermont is experiencing something of a biomass boom. Thirteen percent of the state's K-12 schools already heat with wood. Developers are eyeing a once-shuttered industrial site in North Springfield for the location for a new plant that would generate both heat and electricity.

The Fair Haven permit approval comes just a few weeks after the Biomass Energy Development Working Group released its final report to the Legislature, detailing 47 recommendations for encouraging the growth of Vermont's biomass industry while also maintaining forest health. Among the report's recommendations: encourage wood pellet production; incentivize the biomass industry with tax credits, low-interest loans, or renewable energy credits; and establish wood procurement standards.

The question isn't if biomass use should be expanded, according to the report, but "how?" Gov. Peter Shumlin's Comprehensive Energy Plan states that although the state's forest resources require careful management to remain sustainable "it is clear that Vermont is poised to expand its use of biomass significantly in the coming decades."

But tensions are smoldering over biomass in general and the Fair Haven plant in particular. Supporters sell the plant as a clean and renewable power source that would create 50 full-time jobs and generate badly-needed tax revenue for Fair Haven. Josh Schlossberg, who is based in East Montpelier and writes a monthly national newsletter addressing concerns about biomass, says resistance is brewing behind the scenes in Fair Haven, but declined to reveal opponents' strategies for blocking the proposed plant.

Meanwhile, critics such as Chris Matera of Massachusetts Forest Watch say Vermont is guilty of "big time hypocrisy" for green-lighting a big carbon emitter the same week it joined a multi-state lawsuit against the federal Environmental Protection Agency over soot pollution. 

Photo: McNeil Generating Station in Burlington, Vermont’s largest biomass power plant, courtesy of Chris Matera.

"Just because it's local doesn't mean it's good," says Matera, who says supporters of biomass don't take into account pollution, carbon emissions or deforestation when they tout biomass facilities as beneficial. "I don't think it's any different than people in West Virginia saying coal is local." 

Among the biggest concerns raised by biomass opponents is the plant's possible affect on air quality in the region. Even the newest methods of burning biomass release some small particulates into the air. Which raises the question: Just how dangerous are biomass plants for air quality and human health?

The answer depends on who you ask. It's hard to make generalizations about biomass because figures change dramatically depending on what kind of fuel and technology is being used. When Middlebury College brought a $12 million gasification plant online in early 2009, the college installed a filtration system rated to remove 99.7 percent of particulates.

According to the institution's website, most of the "smoke" that comes out of the facility's stack is, in fact, water vapor. Assistant Director of Facilities Mike Moser confirms that the system is working, and the plant currently emits 0.019 pounds of particulate per million BTUs of fuel heat put into the plant — 20 percent of the maximum 0.091 pounds of particulate allowed under the DEC's air permit for the facility.

Biomass developers point out that plant emissions have to meet federal air quality standards to operate. But even there, opponents aren't satisfied: The standards don't necessarily match up to public well being, Matera says, and that's backed up by a recent study out of Boston that even air pollution considered within healthy levels by the regulations could increase the chance of strokes.

"Air quality standards are not environmental or health related," says Matera. "They’re a political beast. [Companies] know that those numbers are not numbers that protect public health."

Vermont already struggles with higher-than-average rates of asthma. A U.S. Centers for Disease Control and Prevention study ranks Rutland as having the highest per capita rate of adult asthma among all studied metropolitan or "micropolitan" areas. Rhonda Williams, who is the tobacco chief with the Vermont Department of Health, says the state routinely comes out on or near the top in the CDC study for asthma rates, and that New England in general struggles with higher lifetime prevalence of asthma. Some of that is due to prevailing wind patterns that bring in particulates from coal-burning plants in the midwest. Some is due to agricultural dust, or problems with mold. Burning wood with old equipment or at an inefficient temperature also contributes.

When it comes to parsing the biomass debate, the Union of Concerned Scientists has a good 2010 primer on "How Biomass Works" that cuts some distinctions. The UCS says that biomass, like all other kinds of energy production, has its environmental impacts and risks. The group calls for the forestry industry to establish a set of best practices to guide tree harvesting for biomass, and notes that a handful of states have already done so. UCS also points to third-party certification standards and professionally drafted forest management plans as useful tools.

In terms of emissions, the UCS says biomass typically releases far less mercury, sulphur and nitrogen oxide than conventional coal plants. As for particulate matter, technology makes all the difference: Facilities with stoker boilers emit significant amounts of particulates and carbon monoxide — more than most kinds of coal and natural gas plants. Newer technology (like gasification systems) cut particulate matter emissions down significantly.

In Fair Haven, the plant's developers say by way of press release that their DEC permit is evidence of the advanced technology they're bringing to bear for the project. The DEC permit is the first issued to a combined electric generating and pellet manufacturing facility anywhere in the U.S. It's also the first permit issued in Vermont to an electricity generating plant of its size in 20 years.

The plant's developers have submitted an application to the Public Service Board for a certificate of public good, the last key permit the facility needs. The project will also need to settle forest health standards and reach an "interconnection" agreement for connecting to the electrical grid. Spokesman Kevin Ellis says the project's developers are also eagerly watching to see how much renewable energy Vermont lawmakers will require Vermont utilities to acquire in the future.