After 50 years of life in a mill town, Heidi Hale and her husband are accustomed to the plumes of industrial smoke and acrid smells that occasionally waft past their Millinocket home.

But the heavy, offensive-smelling smoke that Hale said has permeated her home and the homes of others in recent years is not a byproduct of the mills that employ hundreds in this North Woods community.

It comes from a backyard wood-burning boiler that has pitted neighbor against neighbor and forced Millinocket into the limelight of an emerging environmental issue.

“Several times we have had major incidences when even with our doors and windows completely closed, we have had significant smoke in our home,” said Hale, who claims the smoke aggravated her respiratory problems. “It’s so obvious when the boiler is fired up. All you have to do is look down the street and all you see is a thick, dense fog of smoke.”

As oil prices continue to rise, more and more Mainers are purchasing outdoor wood boilers as a cheaper alternative for their heat and hot-water needs.

But this outdoor version of an old New England favorite – the trusty kitchen wood stove – is causing flare-ups between neighbors from South Berwick to Fort Kent.

Health and environmental groups have launched campaigns against the largely unregulated wood boilers in Maine and nationwide, claiming the smoky contraptions pose serious health risks to downwind neighbors.

Some owners defend their outdoor wood boilers, saying smoke levels are comparable to wood stoves when the boilers are properly fueled and maintained. While admitting they may not have a place in crowded neighborhoods, they laud their boilers’ low operating costs and take pride in their reduced dependence on foreign oil.

State environmental officials have received dozens of complaints but lack the tools to regulate the boilers. Maine and federal officials, meanwhile, are scrambling to figure out how to deal with wood boilers, especially in populated areas.

“Basically, it always takes a while for bureaucracy to catch up with technology,” said Louis Fontaine, compliance manager with the DEP’s Bureau of Air Quality.

In the meantime, municipalities throughout Maine are looking to follow the lead of Hale’s hometown of Millinocket which recently imposed setback requirements and other restrictions to protect citizens’ health.

Cheaper but dirtier

Outdoor wood boilers are wood-fired furnaces typically housed in small, shedlike buildings. They feature large fireboxes surrounded by a water jacket. Hot water then flows through underground pipes to a nearby home or structure where it can be used both in the plumbing and heating system.

Boilers often operate all day long on just one or two loads of seasoned firewood thanks to a unique feature that allows the owner to “damper down” the unit by reducing oxygen flow.

But state officials and boiler critics claim this feature is the reason the devices are so dirty.

A smoldering fire produces smoke and creosote that build up on the walls of the firebox. When the fire is reinvigorated, the soot and creosote billow out of the boiler’s smokestack. Because boiler smokestacks are generally only 6 to 10 feet off the ground, the smoke may linger and creep into nearby houses.

Health officials claim outdoor wood boilers are among the most polluting types of sources of heat and hot water even when burning clean, seasoned firewood. But their large fireboxes may also encourage some owners to burn trash, tires and other nonwood waste that can spew even more toxins into the air, officials say.

Outdoor wood furnaces typically emit anywhere from 20 to 300 grams of particulate matter, or soot, per hour. Even the cleaner burning models are often several times dirtier than older wood stoves. Newer wood stoves that meet federal air emissions requirements emit just 4 to 7.5 grams hourly.

The wood-fired boilers’ air emissions become even more stark when compared to oil-fired or natural gas furnaces, which emit less than 0.02 grams per hour, according to reports.

Norm Anderson with the American Lung Association of Maine said outdoor wood boilers pollute the air above acceptable federal levels. The association wants a moratorium on the boilers until they can meet the same federal standards applied to wood stoves.

“We want everyone to understand that this is a public health problem and are not only cautioning the public against purchasing these boilers but also alerting the business community that this is an issue with some consequence,” Anderson said. “They need to be aware of that if they are promoting these units.”

The Maine Air Toxics Advisory Committee, the Northeast States for Coordinated Air Use Management (NESCAUM) and numerous environmental groups have also called for regulation of wood boilers.

Owners defend boilers

Several manufacturers and distributors of wood-fired boilers did not return phone calls seeking comment.

Some owners of wood-fired boilers acknowledge that the units do produce more pollution but insist that the technology is appropriate in some rural areas where houses are spaced farther apart.

Gerry Sawyer of Dixmont said he is separated from his nearest neighbor, who also owns an outdoor boiler, by about 800 feet and a patch of woods. Had he lived closer to neighbors, Sawyer said he never would have considered buying a boiler.

“Even in the country, they could be bad,” he said.

Sawyer estimated that he saves about $1,000 a year on winter heating costs by burning wood salvaged from his own property. Even so, Sawyer said he would need to operate the boiler another eight years to recoup the money he invested. And he said boilers are not as care- and cost-free as some people believe.

Dale Hopkins is more gung-ho about his boiler, saying he “wouldn’t be without it” because of the money he saves.

Hopkins said he can see how wood boilers might be inappropriate in neighborhoods where houses are clustered close together. But the Etna resident said he’s talked with his neighbors 200 to 300 yards away and they have no complaints. In fact, he said they like the woody smell.

“As long as people burn wood, it isn’t any different than people having a stove in the living room or in the house,” Hopkins said. “The problem seems to be when people burn trash in it.”

Regulations

Millinocket’s ordinance, which took effect last month, requires boiler owners to apply for a town permit that can be suspended for burning nonpermitted materials.

The ordinance requires boilers to be set back at least 50 feet from neighboring homes and prohibits units that emit more than 27.4 grams of particulate per hour for every 100,000 Btu. Although Btu levels vary by model, the most common models are about 500,000 Btu, according to a NESCAUM report.

Millinocket Town Councilor Scott Gonya, who helped lead the effort to regulate boilers, said town officials from around Maine have inquired about the ordinance. Local officials in Lincoln, East Millinocket, Brewer and Hampden are also considering regulating boilers.

“It’s not about wood burning,” Gonya said. “The people that burn wood think it’s an assault on them, but it’s not. It’s about the health of townspeople.”

The Maine DEP may not be far behind with its own rules.

A proposed resolve the DEP plans to submit to the Legislature calls on the Board of Environmental Protection to adopt rules by January 2008 that “control the sale, installation, siting and use of outdoor wood boilers at residences and places of business” and to implement minimum performance standards for units.

Fontaine with the DEP’s Bureau of Air Quality said he has received about three dozen complaints about wood boilers since 2004. The department’s only recourse at present is a general law regulating the amount of smoke being produced, but DEP inspectors must actually observe the violation.

“It’s something we will go out and look at. But right now, there is nothing we can do,” Fontaine said.

A few states are regulating wood-fired boilers. Vermont, for instance, instituted a setback and stack height requirements in the 1990s and is considering emissions standards. Washington has banned the boilers altogether on grounds that there is no standard emissions testing method to certify the devices.

The federal Environmental Protection Agency is expected to propose a new testing method later this month.

The EPA is working with states and manufacturers on a voluntary program that would make boilers 70 percent cleaner through improved combustion and efficiency. Agency staff are also developing model rules that states or local towns can use to regulate the boilers.

“We’re doing this because we want to get cleaner [boilers] on the market sooner and we want to give states tools that they can use,” said John Millett, a spokesman with the EPA’s Office of Air and Radiation in Washington, D.C. “It’s much speedier than the federal regulatory approach.”

Warm and healthy

A Millinocket company, Clean Wood Heat LLC, claims to have developed a wood-fired boiler that emits just 6.6 grams of particulate per hour. That would place the company’s Black Bear boiler within the EPA’s 7.5-gram level for indoor wood stoves.

Company co-owner Jeffrey Baker advised the Millinocket Town Council on its recently adopted ordinance and also serves on the EPA’s stakeholder committee on outdoor wood boilers.

Beth Thomas isn’t waiting for the state or the feds to act, however.

Thomas, her husband and their two children live about 170 feet from a wood-fired boiler in Bowdoinham. Thomas said she occasionally suffers from headaches, nausea and wheezing and her oldest child has been overcome with dizziness as a result of the smoke.

Thomas said relations with the neighbor have deteriorated to the point where lawsuits have been threatened. And like Heidi Hale in Millinocket, Thomas has talked with local and state officials.

Now she is taking her concerns on the road with Anderson of the American Lung Association. The two are giving presentations around the state, calling for more regulation of the boilers and attempting to educate people about pollution levels associated with the boilers.

“We don’t have a choice,” Thomas said.

Hale, meanwhile, said she is pleased that Millinocket finally adopted rules restricting the location of boilers and hopes that the rule will set a precedent for the state. She said she hasn’t noticed any smoke from her neighbor since the rule went into effect in late November.

“We all want the same thing. We all want to stay warm,” Hale said. “But we also have to stay healthy.”