PODCAST TRANSCRIPT: Residential Wood Heaters 


Becky: Hello! Welcome to this podcast by the Office of Inspector General for the U.S. Environmental Protection Agency. My name is Becky Klingler, and joining me today is Chip Triebwasser, program analyst with the OIG. Welcome, Chip, and thank you for being here. 

Chip: Hi, Becky. I’m happy to be here!

Becky: I read your team’s report about residential wood heaters with much interest, Chip. Like many people, I come from a part of the country where using wood heaters is fairly common. The benefits of these heaters seem obvious; they provide a cheaper and reliable source of heat and energy. But I never realized that they were such significant emitters of dangerous pollutants. Can you tell us a little bit more about that? 

Chip: Sure, Becky. Smoke from residential wood heaters contains various pollutants like carbon monoxide, black carbon, and benzene. In our report, though, we focus on the fine particulate matter pollution emitted by these heaters. When we say fine particulate matter, we’re talking about tiny particles that are 28 times smaller than the diameter of a human hair. They’re so small that, when inhaled, they can get deep into your lungs and can cause lung cancer, heart disease, and even death. 
And as you said, using residential wood heaters is fairly common, especially in certain parts of the country, where wood burning can be part of the culture. It’s estimated that 12 and a half million homes in the United States use wood for energy, releasing about 340,000 tons of fine particulate matter each year and accounting for between 10,000 and 40,000 premature deaths. So this pollution doesn’t just affect the households that use wood heaters. It affects all of us. Also, there’s an environmental justice component to this issue. Many of the external stakeholders we spoke to in Alaska, California, and New York referenced environmental justice concerns in their communities, especially in areas with high wood heater use.

Becky: Since the EPA’s mission is to protect human health and the environment, what is the EPA doing in terms of residential wood heaters? 

Chip: As part of its responsibilities under the Clean Air Act, in 2015 the EPA revised its 27-year-old performance standards limiting fine particulate matter emissions to help make new wood heaters cleaner and less harmful to human health. Basically, manufacturers were obligated to comply with an emission standard of four and a half grams of fine particulate matter per hour by May 15 of that year and, by May 15, 2020, with an emission standard of either 2.0 grams or 2.5 grams, depending on the type of wood used for testing emissions.

Becky: So, given that it is now 2023, all wood heaters should be compliant with the stricter emission standards for fine particulate matter, correct? 

Chip: Well, it’s a bit more complicated than that. First, during our evaluation, we found that the EPA’s standards are based on flawed testing methods. They are unclear and allow for too much flexibility that can be taken advantage of during emissions testing. Plus, we determined that the EPA’s wood heater program — which is responsible for issuing certificates of compliance for each wood heater model line before it reaches the market — is not effectively overseeing the certification process.  Finally, these performance standards only apply to new wood heaters coming to the market, not to ones already in the market. Wood heaters have life spans of twenty or more years, so existing appliances, including some that were tested under the flawed test methods, will continue to be in operation across the country for years and possibly even decades.

Becky: When you say that the standards are based on flawed testing methods and are vague, what exactly do you mean?

Chip: Well, that statement encompasses several issues discussed in our report but let me provide a simple example. One section of the standard says that the labs that perform the emissions tests must report data for all valid tests. Some labs have interpreted that statement to mean that they don’t have to report incomplete tests. In other words, they may not be reporting test runs that they stop when it appears emissions are going to exceed the standards, so the EPA may think – based on the reported data – that the wood heater is, on average, meeting the standards when it actually may not be. 

Becky: Does this mean that wood heaters that are not compliant with the emissions standards may be reaching the public?  

Chip:  Well, when an independent, EPA-approved testing lab tried to replicate the testing for seven wood heaters that were certified using two methods approved by the EPA, none of those seven heaters met the standards, and all seven of them had significantly higher fine particulate matter emissions than they reported in the original tests. The EPA had approved those two testing methods in twenty-eighteen, but then withdrew its approval of them in January 2022. 

Becky: Does this mean that the certificates of compliance issued to wood heaters based on those testing methods were withdrawn, too?

Chip:  No. Unless EPA found significant deficiencies in the original test report, the certificates of compliance are considered valid until their renewal date, which is five years after certification. Becky, our listeners may also be interested to know that, because of these issues, some states told us that they cannot rely on the EPA’s certification process. For example, Alaska has set its own standards and does not allow the sale of wood heaters that it believes the EPA should not have certified. This also has financial implications for the EPA and states like Alaska that have spent federal, state, and local funding on changeout programs intended to replace older, dirtier wood heaters with newer, cleaner models.

Becky: That is interesting. I hadn’t thought about ramifications beyond an increased risk to human health and the environment. Can you elaborate?

Chip: Sure. For example, in just six years, from fiscal year 2015 through fiscal year 2021, the EPA distributed 82 million dollars in grants for these residential wood heater changeout programs. But, because of the issues with the EPA’s testing and certification process, we don’t know for sure that the newer units are actually cleaner – which means that 82 million dollars may have been wasted.

Becky: Is there anything the EPA can do to improve how wood heaters are tested and certified? 

Chip: Absolutely. Our evaluation team determined that the EPA’s wood heater program lacked adequate internal controls to address internal operations, reporting, and compliance. For example, the EPA could have made it easier to review test reports by developing standardized reporting templates, so that all testing labs would have to report the same information. Having a standard template would have made testing labs aware of the EPA’s expectations for how tests should be conducted and reported. Further, the EPA did not exercise its authority to conduct compliance audit tests to validate certification test results. We believe this oversight activity would have significantly strengthened its wood heater program and helped ensure appliances were meeting emission standards.

Becky: And what about the standards themselves?  Is it possible for the EPA to go back to the drawing board on those?

Chip:  The EPA is scheduled to revise the standards this year, which presents an opportunity for the Agency to set clear testing and reporting expectations for wood heaters.

Becky:  You talked about many of the ways the EPA could improve its approach to testing and certifying wood heaters, which you also conveyed to the EPA via six recommendations in the Office of Inspector General’s report.  How did the Agency respond to these recommendations?

Chip: The Agency did not clearly state agreement or disagreement on any of our recommendations, although their response did indicate that they are currently working toward some of them. We will continue to work with the EPA, and we’ll keep everyone updated as to the status of recommendations on our website.

Becky: Your report includes much more detail about the EPA’s residential wood heater program than we were able to cover today, and I encourage our listeners to check out the full report on our website at www.epa.gov/oig. But, for now, we are out of time. Thank you so much for sharing your expertise with us today, Chip. And thank you to our listeners for joining us.