CALIFORNIA AIR RESOURCES BOARD
City Council Chambers
1900 Lake Tahoe Boulevard
South Lake Tahoe, CA
July 14, 1988
88-9-1 Report by Tahoe Regional Planning Agency (TRPA) 001
on Air Quality Programs in Tahoe Basin.
88-9-2 Status Report on Residential Woodburning 004
88-9-3 Public Hearing to Consider the Adoption of a Fee 010
Schedule and List of Substances Pursuant to the
Air Toxics "Hot Spots" Information and Assessment
Act of 1987
Status Report by Tahoe Regional Planning Agency (TRPA) on Air
Quality Programs in the Tahoe Basin.
TRPA, the bi-state planning agency for the Lake Tahoe Air Basin,
will present a report on current air quality in the Tahoe Basin
and on TRPA's efforts related to air quality. This is an
informational item for which no board action is required.
In 1980, Congress ratified a new Bi-State Compact which governs
planning activities in the Tahoe Basin. The Compact requires
TRPA to establish environmental thresholds which include the
strictest of federal, state, or local air and water quality
standards and to develop and adopt a regional plan that provides
for both attainment and maintenance of the thresholds.
In 1978, EPA designated the Lake Tahoe Air Basin nonattainment
for carbon monoxide. The Basin did not attain the national CO
standard by 1987 as was forecast in the 1982 Air Quality Plan.
On June 6, 1988, EPA confirmed the CO nonattainment designation
for the South Lake portion of the Basin. The Placer Co., Washoe
Co., and Carson City portions of the Basin have not shown
exceedances of the CO standard in recent years.
The Basin also exceeds the state standards for CO, PM10 and
State and Local Standards that Apply to Tahoe
The State of California has a high altitude, 8-hour carbon
monoxide standard of 6 ppm that applies to the lake Tahoe Basin.
this standard is under review and scheduled for reconsideration
by the ARB in late 1988.
The state visibility standard for this Basin is 30 miles, as
compared to 10 miles for the rest of the state.
The TRPA has adopted local standards for the Basin which are
different from state standards in some cases. The TRPA standard
for ozone is .08 ppm, adopted for the protection of vegetation.
TRPA's visibility standard separates the urban portions of the
Basin from the non-urban.
The CO problem at Lake Tahoe is attributed to motor vehicle
emissions produced by traffic along the urbanized strip
development area of South Lake Tahoe. The Lake Tahoe Basin will
need a 30% reduction in 8-hour CO concentrations to attain the
national standard and a 50% reduction to attain state and local
PM10 concentrations must be reduced 60% to achieve state and
local standards. Major sources of total particulates are paved
and unpaved roads, wood heaters, and fireplaces.
The basin also exceeds the state visibility standard on a few
days each year. Monitoring is being conducted to more accurately
quantify and define visibility.
AIR QUALITY CONCENTRATIONS
SOUTH LAKE TAHOE
Pollutant Peak No. Violations
CO 8-hour 12.5 ppm 13 days*
PM10 24-hour 124 ug/m3 9 days**
* of National Std. (9 ppm)
** of State Std. (6 ppm for CO and 50 ug/m3 for PM10)
Inspection and Maintenance (I&M)
Although the 1982 Air Quality Plan contained a commitment to I&M,
no program has been implemented. ARB staff analysis indicated
that I&M would have a very small effect on CO violations because
peak concentrations occur when heavy traffic volumes at South
Lake Tahoe are largely composed of vehicles from outside the
Basin. TRPA estimates that during standard exceedances, roughly
80% of traffic is from vehicles registered outside the Basin.
Most of these vehicles (roughly 60-65%) are already subject to
I&M. If I&M were required in the basin, it would have little
benefit during peak CO periods.
EPA has agreed to exempt the Basin from the I&M requirement
provided other measures are substituted.
CO Attainment Strategy
The TRPA is implementing an air quality strategy which will
emphasize a dependence on a cleaner vehicle fleet, the use of
alternative fuels within the Basin, the construction of new
street alignments to relieve the bottleneck of traffic in the
South Lake Tahoe area, and the implementation of transit and land
use measures. TRPA has also implemented an indirect source
Because visibility is so closely tied to the unique environmental
values of the Tahoe region, the TRPA is working on an improved
program for monitoring aerosols, establishing camera stations,
and purchasing other visibility related equipment.
ARB staff is on schedule to propose a new visibility monitoring
method to the Board by the end of the year. This method will
provide a more sophisticated measurement of visibility and
facilitate the development of new standards in the future.
Status Report on Residential Wood Burning Emissions and Controls.
This is a status report, and does not include a recommendation.
Emissions from Residential Wood Burning
Statewide, a total of about 2,700,000 cords of wood are burned
annually in residential wood burning devices, emitting an
estimated 30,000 to 121,000 tons of particulate matter, 90,000 to
640,000 tons of carbon monoxide, and 89 to 160 tons per year of
polycyclic aromatic hydrocarbons. Sulfur dioxide and oxides of
nitrogen are also emitted from residential wood burning, but the
emissions are small compared with other sources of these
Residential wood burning in California follows seasonal and
regional patterns. More wood is burned during the cold winter
months than any other time of the year, and wood consumption on a
per household basis is higher in rural mountainous regions.
Because of these patterns, impacts from residential wood burning
are not uniform throughout the state. Some areas, notably
communities located in rural mountainous areas with cold winter
temperatures, will experience significant impacts from
residential wood burning. As an example of the regional
disparity in wood consumption, the three most populated air
basins, San Diego, San Francisco and South Coast have about 75
percent of the total number of occupied households in the state
but burn less than 45 percent of the total wood consumed. On the
other hand, the smaller rural air basins (Great Basins, Mountain
Counties, Northeast Plateau, Lake Tahoe, North Coast, Lake
County) have 4 percent of the households and burn 16 percent of
the total wood burned.
The three appliances commonly used to burn wood are: fireplaces,
fireplace inserts, and free-standing wood stoves. Statewide,
open fireplaces use about 50 percent of the wood burned in the
state, woodstoves 30 percent, and fireplace inserts, 20 percent.
In rural areas where woodstoves and fireplace inserts are more
commonly found, burning of wood in woodstoves and fireplace
inserts accounts for approximately 70 percent of the total wood
burned in rural wood burning households.
Emissions of air pollutants from residential wood burning include
particulate matter (PM), carbon monoxide (CO), polycyclic
aromatic hydrocarbons (PAHs), nitrogen oxides, sulfur oxides, and
volatile organic compounds. The major components are carbon
monoxide and particulate matter. PAHs are a small component of
wood combustion emissions, but potentially important since they
may contain suspected carcinogenic compounds such as benzo (a)
A variety of variables can affect residential wood burning
emissions. Stove type, burn rate, wood type, and temperature are
among the variables that affect the amounts of pollutants emitted
from a fire. Therefore, there is no one emission factor
representative of all the possible operating conditions. In our
impact analyses, a range of emission factors was used to provide
an emission estimate that should encompass the actual emissions
from residential wood burning.
Air Quality Impacts of Residential Wood Burning
Health Effects: Particulate matter emissions from wood burning
are predominately smaller than 10 micrometers equivalent
aerodynamic diameter. Particles of this size are easily inhaled.
Inhaled particulate matter can interfere with the respiratory
system by affecting the exchange of gases or circulation.
Repeated exposures can cause damage to the lung tissue resulting
in chronic respiratory diseases such as emphysema and chronic
bronchitis. The other major component of residential wood
burning emissions, carbon monoxide, affects the body's ability to
absorb and transport oxygen and has been shown to have an adverse
affect on mental functioning. PAHs from residential wood
combustion may be a source of exposure to potential carcinogenic
Air Quality Impact: To illustrate the impact on air quality that
residential wood burning can have, we estimated wood burning
emissions for the Lake Tahoe Air Basin and Fresno County.
Estimates were based on the coldest winter month for the region.
The impacts from residential wood burning are significant in the
winter due to the increase in wood consumption and to winter
meteorological conditions which limit dispersion of the
pollutants. For these two areas the emission estimates are as
Lake Tahoe Fresno County
Emissions, pounds per day
PM 4,000-18,000 20,000-82,000
CO 12,000-102,000 48,000-440,000
PAHs 14-26 60-120
One study estimated that for South Lake Tahoe residential wood
smoke can account for approximately 40 percent of the fine
particle mass concentration and for up to 50 percent of the
visibility impact. Based on a 1985 Tahoe Regional Planning
Agency emission inventory, on a typical winter day, residential
wood burning releases 57 percent of the total particulate matter
emitted into the basin. Estimates by the ARB Modeling Support
Section staff verify such impacts.
Based on an ARB emission inventory seasonal analysis fro Fresno
County, particulate mater emissions from residential wood burning
can account for up to 24 percent of the total PM10 loading on a
typical winter day. (Range 7 to 24 percent)
Control of Emissions from Residential Wood Burning
For new wood stoves and inserts, the following low emission
designs are available:
a. catalytic models
b. low-emission non-catalytic models with some or all of these
-- baffle plates
-- small firebox size
-- preheated secondary air
-- firebrick and metal liners for fireboxes
-- upper firebox inlet for primary air
-- increased heater mass
c. pellet stove models
For new fireplaces, potential controls include catalytic designs
and insert requirements. Catalytic designs include catalytic
liners, fireplace throat catalysts, and stack catalysts.
For existing wood stoves and inserts, the following control
technologies are available:
a. retrofit catalytic devices
-- added in stack
-- added in stove
b. possible non-catalytic appliance modifications
-- baffle plates
-- preheated secondary air
-- firebrick and metal liners for fireboxes
-- upper firebox inlet for primary air
-- increased heater mass
Existing fireplace emissions can be reduced with low-emission
Existing Regulations: The Environmental Protection Agency
promulgated on February 26, 1988, New Source Performance
Standards for residential wood heaters. The standards consist of
emission limits for wood burning devices and a program to certify
new wood heaters manufactured after July 1, 1988. a second phase
of the requirements sets more stringent emission limits for wood
heaters manufactured after July 1, 1990. The EPA standards will
require residential wood burning devices to be either of high-efficiency
design or equipped with a catalyst. Open fireplaces,
boilers, furnaces, and cookstoves are not subject to these
Emission control strategies for residential wood burning
appliances have been implemented by state agencies in Alaska,
Colorado, Montana, Oregon, and Washington. The states of
Colorado and Oregon have mandatory certification programs to
reduce emissions from residential wood burning. Alaska has
opacity limits and provisions for burning curtailment for
residential wood burning. Montana has adopted an income tax
incentive to encourage the replacement of wood stoves with wood
stoves that meet the Oregon wood stove certification
In addition to the above state agency regulations, there are
local agencies that have adopted regulations to deal with specific
regional air quality problems. States with local residential
wood burning regulatory programs are: Alaska, California,
Colorado, Massachusetts, Montana, Nevada, New Mexico, New York,
Oregon, and Washington.
Several ski communities within Colorado have adopted their own
regulations in response to regional air qualty concerns. Aspen,
Beavercreek, Pitkin County, Snowmass Village, Telluride and Vail
have adopted some or all of the following requirements within
a. limiting new residential and commercial establishments to
b. mandating the use of heat efficient fireplaces;
c. prohibiting the burning of coal;
d. providing weatherization standards for new construction; and
e. establshing maximum allowable concentrations for specific
Telluride has adopted a regulation that requires, by October 15,
1988, all open fireplaces to be retrofitted with a Colorado-certified
fireplace insert or to be replaced with a liquid fuel
device. Also, no open fireplaces will be allowed in new
construction in Telluride.
Nevada does not have state regulations for residential wood
burning. However, Washoe County (the county in which Reno is
situated) in Nevada has adopted a regulation that curtails
residential wood burning during high pollution days and restricts
wood stove sales to those stoves which meet either Oregon or
Colorado emission certification requirements.
In California, the Tahoe Regional Planning Agency, Placer county,
and the City of Cloverdale (Sonoma County) have adopted
requirements for residential wood burning appliances. These
requirements include some or all of the following:
a. emission standards for new appliances;
b. properly sized woodstoves;
c. fuel type restrictions; and
d. prohibiitons on wood heating for certain commercial
Further Staff Efforts
The Air Resources Board staff has identified a number of options
that could reduce emissions from residnetial wood burning. The
Environmental Protection Agency's New Source Performance
Standards are effective on July 1, 1988. We are working with the
Technical Review Group to facilitate district adoption so the New
Source Performance Standards can be delegated to the districts.
We will also be working with the Technical Review Group to
evaluate the emission reduction options that are appropriate for
inclusion in a suggested control measure that would address the
impacts of emissions from residential wood burning in existing
devices in California. The options to be evaluated are listed
a. requiring inserts in fireplaces;
b. retrofit devices;
c. public education;
d. restricting the number or type of wood burning devices in
e. visible emissions limits;
f. burning curtailment;
g. fuel-type requirements;
h. economic incentives for appliance replacement; and
i. weatherization and stove sizing requirements.
Public Hearing to Consider Adoption of a Fee Schedule and List of
Substances Pursuant to the Air Toxics "Hot Spots" Information and
Assessment Act of 1987. (regulatory)
The ARB staff recommends that the Board adopt the proposed list
of substances and fee regulation for recovery of costs incurred
by ARB, air pollution control districts and the Department of
Health Services (DHS) during implementation of the Act (AB 2588)
in fiscal year 1988-89.
What the AB 2588 Program is.
AB 2588 requires the ARB to compile and maintain a list which
contains specified toxic substances which present an acute or
chronic threat to public health. The statute also establishes a
program to inventory air toxics emissions, to assess the risk to
public health from exposure to these emissions, and to notify the
public of any significant health risks associated with toxic
emissions from any facility. To recover costs of the program to
ARB, districts and DHS, AB 2588 requires that the Board adopt a
fee schedule by August 1, 1988.
The proposed fee regulation sets forth two fee options. both
provide for recovery of state costs and district costs as
submitted to the ARB by each district. A district must choose
either a cost per facility fee based on five graduated criteria
pollutant emission categories, or a cost per ton fee also based
on emissions of criteria pollutants. The option selected by each
district will be presented to the Board at the hearing along with
any revisions that have been made in the district cost estimates
and fee amounts. The proposal also includes a flat fee for
facilities listed on a current district air toxics use or toxics
air emissions survey, report or inventory.
Responsibilities: Who Does What.
To accomplish AB 2588 program goals, ARB, DHS, and the air
pollution control districts are given specific responsibilities.
In addition to the fee schedule and list of substances, ARB is
required to develop criteria and guidelines for the emissions
inventories which each facility must perform. ARB is also
required to develop an emissions database, an inventory of
mobile, area and natural sources, inventory update procedures,
and a report specify