CALIFORNIA AIR RESOURCES BOARD
Auditorium, First Floor
400 "P" Street
November 8, 1989
89-18-1 Public Hearing to Consider the Adoption of a 1
Regulation to Reduce Volatile Organic Compound
Emissions From Antiperspirants and Deodorants.
89-18-2 Public Hearing to Consider the Adoption and 133
Amendment of Regulations Regarding Test Methods
for Determining Emissions from Nonvehicular Sources.
89-18-3 Public Meeting to Consider Approval of a 469
Suggested Control Measure for the Control of
Emissions from Residential Wood Combustion.
89-18-4 Public Meeting to Consider Approval of a 626
Procedure Relating to the Determination of
Agricultural/Forestry Waste Emission Offset Credits.
Litigation -- Authorized by Govt. Code Section 11126
(q)(1); Citizens for a Better Environment v.
Deukmejian, et al., and Sierra Club v. Metropolitan
Transportation Commission, et al.
Proposed Suggested Control Measure for the Control of Emissions
from Residential Wood Combustion.
We recommend that the Air Resources Board approve the Suggested
Control Measure and direct the Executive Officer to forward it to
appropriate local air pollution control agencies for their use in
developing regulations to reduce emissions from residential wood
About 6 million tons or 2.7 million cords of wood are burned
annually in residential wood-burning appliances in California.
Statewide, residential wood combustion generates 80-370 tons per
day of PM10 (particulate matter with an equivalent aerometric
diameter less than 10 microns) 280 to 2,100 tons per day of
carbon monoxide (CO) and about 0.30 to 0.50 tons per day of
polycyclic aromatic hydrocarbons (PAHs).
The appliances commonly used to burn wood are fireplaces and wood
heaters which include fireplace inserts and free-standing
woodstoves. Fireplaces are very inefficient and are used mainly
for aesthetic reasons. Fireplace inserts and woodstoves, on the
other hand, are much more efficient heat sources and in some
residences they are used as primary sources of heating.
Residential wood-burning follows seasonal and regional patterns.
More wood is burned during the cold winter months than at any
other time of the year and wood consumption on a per household
basis is higher in rural mountainous regions than in urban areas.
During the wintertime, the meteorological conditions compound the
problems associated with air pollutants that are emitted from
residential wood combustion. The air is likely to be more
stagnant due to temperature inversions, which can persist for
long periods of time. During these inversions, air pollutants
remain trapped in the stagnant air mass and accumulate near the
Emission control technologies
On February 26, 1988, the Environmental Protection Agency
promulgated New Source Performance Standards for new residential
wood heaters. Phase I of the regulation requires that after July
1, 1990, catalytic wood heaters must be certified to meet a 5.5
grams per hour particulate matter emission standard and
non-catalytic wood heaters must meet a 8.5 grams per hour
standard. Phase II requires that new wood heaters sold after
July 1, 1992 must meet more stringent standards of 4.1 grams per
hour for catalytic heaters and 7.5 grams per hour for
At this time, there are catalytic and non-catalytic wood heaters
available to meet Phase I or Phase II standards. Both catalytic
and non-catalytic wood heaters burn wood at much higher
efficiencies than conventional wood heaters, thereby decreasing
PM10 emissions by 45-70 percent.
Add-on catalytic or retrofit devices have the potential to reduce
emissions from some existing conventional wood heaters. Some
catalytic devices are reported to reduce PM10 emissions by about
50 percent. However, these devices need to be further developed.
There are presently no acceptable or proven emission control
technologies being used on fireplaces that will reduce PM10
Suggested control measure
The SCM consists of a list of emission control strategies which
are summarized as follows:
Public awareness programs. Retailers of wood heaters will be
required to have available to customers, public information that
includes pamphlets or other information discussing the proper
operation and maintenance of wood heaters and health effects of
Replacement of existing wood heaters. Upon the sale of real
property that contains a wood heater, the heater must be an
EPA-certified, Oregon-certified, or pellet-fueled wood heater.
EPA Phase II requirements. This strategy will accelerate the
implementation date by a year and a half, new wood heaters
meeting EPA's Phase II requirements by January 1, 1991.
Sale of Used wood heaters. After January 1, 1991, used wood
heaters that are offered for sale must be EPA-certified,
Oregon-certified, or be pellet-fueled.
Moisture content of seasoned wood. Firewood that is offered for
sale as "seasoned wood" must have a moisture content of 20
percent by weight or less.
Prohibited fuel types. Garbage, treated wood, plastic, rubber,
waste petroleum products, paints and paint solvents, and coal
having a sulfur content exceeding more than one percent by weight
are prohibited from being burned in a residential wood-burning
Voluntary curtailment program. This program involves the
voluntary curtailment of the use of wood heaters and fireplaces
during poor air quality conditions.
Optional Control Strategies.
A number of possible strategies are not included in the SCM.
These are considered to be optional and are included as
additional strategies that some districts may wish to consider.
Economic incentives for wood heater replacement,
Limits on the number of fireplaces in new single home or
Removal of existing conventional wood heaters as a condition
for the new residential development,
Use of alternative fuels,
Retrofit of existing wood heaters, and
Mandatory curtailment program.
The implementation of the SCM should result in reduced emissions
from residential wood combustion. Because of the lack of
information and the nature of the control strategies, we are not
able to quantify the emission reduction for each strategy in the
suggested control measure. However, for the scenario of
replacing an existing wood heater with and EPA-certified Phase II
wood heater, the SCM is estimated to reduce emissions by 50 to 70
percent or 50 to 60 pounds per year per unit.
Cost of controls
The installed costs for an EPA certified Phase I or Phase II wood
heater range from $1,000 to $2,500. The fuel savings from
replacing a conventional wood heater with an EPA-certified unit
ranges from $70-$125 per year, based on wood usage rates from
about 1.9 to 3.5 cords per year. For the scenario of replacing a
conventional wood heater with a certified wood heater upon the
sale of real property the cost-effectiveness estimates range from
$3.5 to $5.0.
No significant adverse environmental impacts have been identified
from the implementation of the proposed suggested control
These low emitting wood heaters will also reduce the formation of
creosote, which is the principal contributor to chimney fires.
The reduction in wood consumption will also reduce the amount of
global warming gases emitted.
Public meeting to consider approval of proposed changes to A
Procedure Relating to the Determination of Agricultural/Forestry
Emission Offset Credits (AB 2158, Condit. 1987).
Approve the proposed changes and recommend that districts
incorporate the amended procedure into their New Source Review
At its June 1988 meeting, the Board approved the AB 2158
procedure for the calculation and use of agricultural/forestry
emission offsets. AB 2158 was passed in 1987 and amended the
requirements of Health and Safety Code Section 41605.5. It
required the districts and the Board, in cooperation to develop a
procedure to determine the magnitude of offset credits available
to facilities which propose to use agricultural, forestry, or
similar wastes as fuel in a boiler to produce steam or
electricity, or to be used as a feedstock in a digester which
will produce animal feed at a cogeneration facility.
The purpose of the procedure is to allow the granting of emission
offset credits to projects that burn (or digest in a cogeneration
facility) waste material that would otherwise be open-field
burned. The credit recognizes the reduction in emissions that
can occur when these wastes are not open burned.
Air pollution control districts and air quality management
districts currently use the procedure as part of the process for
deciding whether to authorize construction of projects that burn
or digest agricultural waste.
At the June 1988 meeting, the Board instructed the ARB staff and
the committee to review the procedure and return with
recommendations in answer to these questions:
Should the procedure be modified to include a profiling
requirement to prevent net increases in emissions during
certain times of the year?
Should the procedure include special provisions for changes
in fuel mix for facilities that have already received
permits to construct or operate?
What is Emissions Profiling?
Emissions profiling refers to the matching of emission reductions
to the same time period as the proposed emission increase from a
new or modifying facility. The intent of this is to prevent the
transfer of emissions from one time of year to another. For
example, orchard prunings are ordinarily open burned during the
late winter and early spring, while a facility using only orchard
prunings for offset credits would generate emissions year round.
With a requirement for granting credits only for the time of year
that specific wastes would be open burned, projects would need to
use a variety of waste types burned at different times throughout
the year to offset the year-round emissions from the facility.
The ARB staff let two contracts to develop additional data on the
seasonality of open burning. The ARB staff and the committee
also conducted two public consultation meetings to discuss
available data and proposed options to address the profiling and
fuel changes questions. As a result of this work and the
comments received, the ARB staff and the committee proposes the
following to update the 1988 procedure:
Emissions Profiling - Add a quarterly profiling requirement
for new and modifying facilities, as defined in district
Changes in Fuel Mix - Fuel changes should be handled by air
pollution control districts on a case by case basis and in
accordance with district rules.