March 14, 2018
New Residential Wood Heaters: Potential Impacts from
Delaying Federal Emission Standards
On March 7, 2018, the House passed H.R. 1917, which
Types of Residential Wood Heaters
would, among other things, delay the effective date of
federal emission standards for new residential wood heaters
Wood stoves are appliances that burn wood to produce heat.
promulgated by the U.S. Environmental Protection Agency
Consumers may use them as a primary or secondary source of
(EPA) in 2015. House and Senate hearings in late 2017
heat. Wood stoves are typically made out of cast iron, steel, or
highlighted concerns about inadequate time to demonstrate
stone.
compliance with emission standards by the 2020 deadline.
Pellet stoves are similar to wood stoves except that they burn
Others have expressed concerns about the air quality
fuel made of ground, dried wood and other biomass wastes
impacts of delaying the 2020 deadline.
compressed into pellets. They operate by pouring pellets into a
hopper that feeds into the stove. Most require electricity.
The legislation also raises questions about state- and local-
Hydronic heaters (also called outdoor wood heaters or
level impacts. For example, one witness testified that a
outdoor wood boilers) are typically located outside the buildings
delay could negatively affect jurisdictions in which wood
they heat and are often housed in small sheds with short
smoke emissions already make it difficult to meet federal
smokestacks. They typically burn wood to heat liquid that is
air quality standards.
piped to provide heat and hot water to occupied buildings such
as homes and barns.
This In Focus explores how the legislation might interact
with state- and local-level emission standards. For more
Forced air furnaces (also called warm-air furnaces) are
information about the federal standards, their potential
designed to burn cordwood, wood pellets, or wood chips to
impacts, and stakeholder views, see CRS Report R43489,
heat an entire residence. Typically located indoors, these
EPA’s Wood Stove / Wood Heater Regulations: Frequently
furnaces distribute heat through ducts using a blower fan.
Asked Questions, by James E. McCarthy and Kate C.
Shouse.
Source: EPA, “Burn Wise—Types of Appliances,”
https://www.epa.gov/burnwise/burn-wise-types-appliances.
Background
Are Wood Heaters Subject to State and
EPA found that wood smoke—a mixture of fine particles,
Local Standards?
carbon monoxide, volatile organic compounds, and toxic air
pollutants emissions—causes respiratory illness and
State and local jurisdictions have enacted measures to
premature death in some people at certain exposures.
address wood smoke emissions. For example, Washington
Nationally, EPA estimated that wood smoke emissions
State promulgated woodstove emission standards in 1995
account for nearly 25% of all area source toxic cancer risks
that were more stringent than federal standards. Other states
and 15% of non-cancer respiratory effects (EPA,
promulgated regulations limiting emissions from residential
“Standards of Performance for New Residential Wood
hydronic heaters before these heaters were subject to
Heaters, New Residential Hydronic Heaters and Forced-Air
federal emission standards. As a result, prior to 2015, wood
Furnaces,” 80 Federal Register 13673, March 16, 2015).
heaters sold to consumers in certain jurisdictions were
required to meet tighter emission standards than those at the
EPA first promulgated wood heater emission standards in
federal level.
1988 under the Clean Air Act. The standards are called
New Source Performance Standards (NSPS), and they
Stakeholders, including manufacturers and environmental
apply only to new, residential wood heaters.
groups, supported the 2015 NSPS rule in part because it
provided uniformity of standards across the country. There
In 2015, EPA revised the standards for woodstoves and
had been broad concerns about the patchwork of state
pellet stoves and established first-ever federal standards for
regulations and voluntary programs addressing wood
other types of new residential wood heaters. The newly
smoke.
added heaters included indoor and outdoor boilers (also
known as “hydronic heaters”
How Would a Delay Affect State and
), forced air furnaces, and
Local Programs?
single burn rate stoves. (See the text box for descriptions.)
It is unclear how delaying the 2020 Step 2 effective date in
The 2015 NSPS is implemented through a two-step process
federal standards would affect state and local programs.
over a five-year period. Step 1 standards became effective
State or local standards could potentially negate a delay to
in 2015, while the more stringent Step 2 standards are to
the effective date of the federal standards, but there is not
become effective in 2020.
enough information to determine the likelihood of this
scenario. The status of state and local regulations for wood
heaters is not systematically tracked, thereby making it
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difficult to determine whether manufacturers would be
State
Regulation
subject to more stringent standards in some jurisdictions in
the event of a delay to the federal standards effective date.
Wisconsin
Chapter NR 440, Standards of Performance for
New Stationary Sources
In short, the applicability of state regulations would need to
be evaluated on a case-by-case basis.
Notes: List based on CRS research.
What Do We Know About Wood
State and local jurisdictions may also incorporate emission
Heater Emission Standards at the State
standards for residential wood heaters into county-level
and Local Level?
ordinances or state air quality planning documents for
Various state and local jurisdictions have promulgated
attaining national air quality standards. For example, some
regulations or ordinances for wood heater emissions. Some
local governments in Minnesota have adopted ordinances
state regulations incorporate the federal standards by
addressing outdoor hydronic heaters (see
reference (e.g., referencing 40 C.F.R. Part 60, subpart
https://www.pca.state.mn.us/air/wood-smoke).
AAA). At least one state wrote the Step 2 deadline into
state regulations (Colorado, 5 CCR 1001-6 No. 4).
Another example is Alaska, which recently amended its
State Implementation Plan for attaining air quality
Table 1 presents examples of states with regulations that
standards to address requirements for wood-fired heating
reference the federal wood heater NSPS.
devices located in a nonattainment area. In 2017, an Alaska
nonattainment area—Fairbanks North Star Borough—was
Table 1. Examples of State Wood Heater Regulations
reclassified from moderate to serious nonattainment for fine
particle pollution. According to EPA Region 10, “Fairbanks
North Star Borough faces an especially difficult challenge
State
Regulation
of meeting existing pollution standards for a number of
reasons including a high reliance on woodstoves and wood
Colorado
5 CCR 1001-6 No. 4, Sale and installation of
heaters to stay warm” (EPA, “EPA, Alaska to Work
wood-burning appliances and use of certain
Together on Improving Fairbanks Air Quality,” press
wood-burning appliances during high pol ution
release, May 1, 2017, https://www.epa.gov/newsreleases/
days
epa-alaska-work-together-improving-fairbanks-air-quality).
Georgia
Ga. Comp. R & Regs. r.391-3-1-.02 Section 8,
Potential Issues for Congress
“New Source Performance Standards”
The Senate may consider legislation similar to H.R. 1917
Maine
Code of Maine Regulations 06-096-143,
that would provide wood heater manufacturers more time to
Chapter 143, “New Source Performance
certify compliance with the Step 2 emission standards.
Standards (NSPS)”
Supporters of the legislation have stated that a delay would
allow an industry dominated by small businesses to conduct
Massachusetts 310 CMR 7.26(50)-(54), MassDEP Wood-Fired
more cost-effective product development. Those opposed to
Boiler Regulation
the legislation have raised concerns about the impact of a
Minnesota
Minnesota Administrative Rules, Section
delay on air quality. The legislation also raises questions
7011.2950
about the interaction of federal and state-level regulations.
Missouri
10 CSR 10-6.070, New Source Performance
Congress may consider potential unintended consequences
Standards
of a delay given the variety of state and local measures
addressing wood smoke emissions. For example, delaying
New
Chapter 125-R: Outdoor Wood-Fired
the effective date of the federal standards could introduce
Hampshire
Hydronic Heaters
regulatory uncertainty in jurisdictions that may have
Oregon
Oregon Administrative Rules Chapter 340,
promulgated the 2020 deadline in state code or otherwise
Division 262, Heat Smart Program for
factored it into plans for meeting air quality standards.
Residential Woodstoves and Other Solid Fuel
Some jurisdictions may have enacted standards that negate
Heating Devices
a delay to the federal effective date, while others may have
incorporated federal regulations—and subsequent updates
South
S.C. Code Regs 61-62.20, South Carolina
to those regulations—by reference. CRS cannot predict how
Carolina
Designated Facility Plan and New Source
a state might interpret its own regulations or respond to any
Performance Standards, “Title 40 C.F.R. Part 60
change in federal rules.
Subparts Incorporated by Reference”
Vermont
Vermont Air Pol ution Control Regulations 5-
Kate C. Shouse, Analyst in Environmental Policy
204, “Wood Stoves and Central Heaters”
IF10844
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New Residential Wood Heaters: Potential Impacts from Delaying Federal Emission Standards
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