HomeMy WebLinkAbout2000-05-01 City Council (7)City of Palo Alto
City Manager’s Report
TO:
FROM:
HONORABLE CITY .COUNCIL
CITY MANAGER DEPARTMENT: PLANNING AND
COMMUNITY ENVIRONMENT
DATE:MAY 1, 2000 CMR:233:00
SUBJECT: ORDINANCE REGULATING CONSTRUCTION OF WOOD-BURNING
¯FIREPLACES (WOOD-SMOKE ORDINANCE)
RECOMMENDATION
Staff recommends that the Council adopt the attached Wood-Smoke Ordinance (Attachment
A), which would prohibit the construction of new wood-burning fireplaces in residential
construction.
BACKGROUND
In February 1999, staffwas directed by Council to examine the issue of problems caused by
smoke from wood-burning activities, particularly fireplace use. ¯ Staff was further directed
to explore the feasibility of drafting an ordinance that would regulate wood-smoke pollution
and, accordingly, minimize the respiratory and other health problems associated with it.
Since that time, staff from the City Attorney’s Office, Public Works Department, and
Planning and Building Divisions have examined the issue and arrived at measures intended
to minimize the adverse impacts posed by wood-smoke pollution.
Given the regional nature of air quality issues, staff contacted the Bay Area Air Quality
Management District (BAAQMD) regarding potential regulatory means by which to deal
with wood’smoke pollution. The BAAQMD, which is a State-e~tablished regulatory agency
that oversees the nine-county Bay Area region regarding air quality matters, was able to
provide staff with information on the issue of wood-smoke. Based on scientific evidence
establishing that wood-smoke pollution poses potentially serious respiratory health risks, the
BAAQMD, in December 1998, developed a non-binding Model Ordinance (Attachment B)
that could be adopted in whole or in part by Bay Area municipalities. The Model Ordinance
regulates wood-smoke pollution in the following three ways:
1.It prohibits the installation of wood-burning fireplaces in new construction, including the
installation of new fireplaces in the remodeling of existing buildings;
CMR:233:00 Page 1 of 4
It prohibits the use of.wood-buming fireplaces, unless an altemate heat source is not
available, during BAAQMD "Spare the Air Tonight" warnings. These wamings are
issued only when climatic conditions are such that wood-burning impacts can be
particularly severe;
3.It prohibits the burning of inappropriate materials (e.g., garbage, treated wood, coal) in
existing fireplaces designed for the burning of wood. ¯
DISCUSSION
After researching the issue of wood-smoke pollution, including further discussing of the
issue with BAAQMD staff, meeting with wood-burning appliance industry representatives,
and reviewing other jurisdictions’ regulations pertaining to wood-smoke pollution, staff
concluded that there are two approaches through which the City could address the issue: 1)
adoption of the BAAQMD’s Model Ordinance, or elements thereof, and 2) inauguration of
a public outreach or education program.
Since Council had specifically directe’d staff to analyze drafting an ordinance to regulate.
wood-smoke pollution, staff focused, its efforts there. Using the BAAQMD’s Model
Ordinance as a basis, staff assessed which features would work most effectively under the
City’s particular circumstances. It was then. decided that limiting the applicability of the
Wood-Smoke Ordinance to new construction, including the remodeling of existing
residences, would be the City’s best option.
Staff opted not to include the Model Ordinance’s provision related to "Spare the Air
Tonight" warnings because of the infrequency with which the BAAQMD issues them (the
most recent warning occurred 1992), and due to potential enforcement and notification
problems (e.g., how would residents be made aware that sucha warning was in effect?).
Similarly, a provision regarding the burning of inappropriate materials was not included in
the-City’s ordinance due to potential enforcement difficulty. If either of these provisions
were included in the City’s proposed ordinance, enforcement of them would likely require
City staff to intervene while the violation was occurring.
As proposed, the City’s Wood-Smoke Ordinance limits the construction of new wood-
burning fireplaces in residential structures. The ordinance prohibits new wood-burning
fireplaces from being constructed in any residence, including additions to, or the remodeling
of, existing residences. The ordinance would not prohibit the construction of all types of
fireplaces or place a limitation on the total number of fireplaces a residence may have, only
those that are designed to bum wood. Additional fireplaces would be allowed under the
ordinance, but would need to be constructed to use a fuel source other than wood, such as
gas, or, if wood-burning, would need to comply with EPA emission standards for wood-
burning appliances. Presently, EPA certification standards exist for wood heaters and wood-
burning fireplace inserts, not traditional masonry-construction fireplaces. Should the EPA
CMR:233:00 Page 2 of 4
develop a certification program for masonry-construction fireplaces, the proposed ordinance
would allow fireplaces so certified to be constructed in new residential development. Also,
whether installed in commercial or residential structures, wood-burning appliances designed
exclusively for food-cooking purposes (e.g., mesquite grills, wood-fired ovens) are exempt
from the ordinance’s provisions. This exemption applies to both indoor and outdoor cooking
appliances.
Staff executed a public awareness program concerning woodsmoke during the Winter of
1999-2000, as envisioned in the Comprehensive Plan. Newspaper ads, a utility bill stuffer,
and outreach at events and meetings were used to explain the air and water pollution
problems associated with woodsmoke. Residents were urged to minimize fn’eplace burning,
to burn hardwood, to burn compressed logs, to avoid burning trash and plastic, and to keep
fires burning hot. These practices will help to minimize pollutant releases from existing
fireplaces. New or remodeled fireplaces were not discussed pending consideration of the
attached Ordinance.
ALTERNATIVES TO STAFF RECOMMENDATION
There area variety of altematives to the proposed Wood-Smoke Ordinance. The ordinance
could be made more restrictive by being modified to mirror the BAAQMD’s Model
Ordinance. However, as noted above, this raises important issues conceming enforcement.
Staff believes that the key element of the Model Ordinance is the prohibition of installation
of wood-burning stoves in new construction, and has solicited and received BAAQMD’s
support of this position. A more restrictive ordinance could be adopted by extending the
ordinance’s applicability to wood-buming appliances other than fireplaces (e.g., those used
for cooking purposes). The ordinance could be amended to include non-residential uses
(e.g., restaurants, hotels). And, finally, a less restrictive approach could be taken and the
Council could opt to focus solely on public outreach and incentive programs, foregoing the
adoption of an ordinance at this time.
RESOURCE IMPACT
As proposed, the Wood-Smoke Ordinance would not impact City resources. The ordinance’s
provisions would be met through existing Planning and Building Division procedures.
POLICY IMPLICATIONS ’
The proposed Wood-Smoke Ordinance is consistent with the following Comprehensive Plan
policies and programs:
¯Policy N-26: Support regional, state, and federal programs that improve air quality in the
Bay Area.
¯Policy N-27: Reduce emission of particulates from wood-burning stoves, construction
activity,, automobiles, and other sources.
¯Program N-39: Assist the Bay Area Air Quality Management District (BAAQMD) in
its efforts to achieve compliance with existing air quality regulations.
CMR:233:00 Page 3 of 4
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¯Program N-42: Require all new wood-burning stoves or fireplace inserts to comply with
EPA-approved standards.
ENVIRONMENTAL REVIEW
This action is exempt from the provisions of the California Environmental Quality Act
(CEQA) per Section 15061(b)(3) of CEQA Guidelines, since it can be seen with certainty
that there is no possibility that the action may have a significant effect on the environment.
ATTACHMENTS
Attachment A: Wood-Smoke Ordinance
Attachment B: BAAQMD Model Ordinance
Attachment C: Letter and enclosures from the BAAQMD to Honorable Mayor Liz Kniss and
City Council Members, dated April 21, 2000
Woodburning Handbook (Council Members only)
PREPARED BY:Luke Connolly, Senior Planner
DEPARTMENT HEAD:
G. EDWARD GAWF MI
Director of Planning and Community Environment
" EMILYIqARRISON
Assistant City Manager
CMR:233:00 Page 4 of 4
ORDINANCE NO.
ORDINANCE OF THE COUNCIL OF THE CITY OF PALO ALTO
ADDING CHAPTER 9~06 TO TITLE 9 OF THE-PALO ALTO
MUNICIPAL CODE TO. PROHIBIT NEW CONSTRUCTION OR
REPLACEMENT OF WOOD BURNING FIREPLACES AND
APPLIANCES
The Council of the City of Palo Alto does. ORDAIN as
follows:
SECTION i. The City Council finds and declare~ as follows:
A. Wood smoke is a significant contributor to pollution
levels that pose significant health risks; and
B. The City of Palo Alto desires to lessen the risk to
life and property from air pollution from wood burning appliances;
and
C. The City of Palo Alto finds that the ordinance will
significantly reduce-the increase in particulate emissions from
future wood burning appliance installation and construction
activities.
SECTION 2. Chapter 9.06 of Title 9 of the Palo Alto
Municipal Code is hereby added as follows:
9.06.010 Definitions.
The following words and phrases whenever used in this
chapter shall be construed as defined in this section, unless the
context indicates otherwise.
(a) "Bay Area Air Quality Management District" means the
air quality agency for the San Francisco Bay Area pursuant to
California Health and Safety Code section 40200.
(b) "Fireplace" means any permanently.installed masonry or
factory-built wood burning appliance, except a pellet-fueled wood
heater, designed to be used with an air-to-fuel ratio greater than
35 .to i.
(c) "Gas fireplace" means any device designed to burn
natural gas in a manner that simulates the appearance of a wood
burning fireplace and does not burn anything other than natural
gas
(d) "Newly-Built" means any building activity for which a
building permit is required, including remodeling, additions,
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reconstruction or rehabilitation, which occurs on or after June 30, ~.
2000.
(e) "Wood burning appliance" means fireplace, wood heater,
or pellet-fueled wood heater or any similar device burning any
solid fuel used for aesthetic or space-heating purposes. Wood
burning appliance does not include stoves used exclusively for
cooking food for human consumption.
9.06.020 Applicability.
This chapter shall apply to all wood burning appliances
that are:
(a) Installed on or after June 30, 2000 in Newly
Built or existing residential structures, commercial structures, or
other non-residential structures.
9.06.030 General Requirements.
It shall be unlawful to:
(a) Install a wood-burning appliance in Newly Built
residential, commercial, or other non-residential structure.
9.06.040 Exemptions.
The following devices shall be exempt from this chapter:
(a)Gas fireplaces;
(b)a pellet-fueled wood heater;
(c)an EPA certified wood heater; or
(d)a fireplace certified by EPA should EPA develop
a fireplace certification program; or
(e) new fireplaces in Newly Built or existing
~ residential, commercial or other non-residential
structures that replace an existing,lawfulfireplace; or
(f) outdoor fireplaces.
9.06.050 Enforcement.
Any person violating any of the provisions of this chapter
shall be deemed guilty of an infraction. Violations of this chapter
shall alsobe deemed a public nuisance.
000427 sdl 0052252 2
SECTION 3. The City Council finds that this project is
exempt from the provisions of the Environmental Quality Act
("CEQA") because it can be seen with certainty that there is no
possibility that this project will have a significant advegse
effect on the environment.
INTRODUCED:
PASSED:
AYES:
NOES:
ABSTENTIONS:
ABSENT :
ATTEST:APPROVED:
City Clerk Mayor
APPROVED AS TO FORM:
City Attorney
City Manager
Director of Planning &
Community Environment
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Bay Area Air I
Attachment B
A MODEL ORDINANCE PERTAINING
TO THE REDUCTION OF AIR POLLUTION BY REGULATING THE
NEW CONSTRUCTION OR REPLACEMENT OF WOODBURNING APPLIANCES
BE IT ORDAINED BY the City or County of
[]:
WHEREAS, the State Air Resources Board (ARB) adopted a particulate matter (PM10) Ambient
Air Quality Standard (AAQS) in December, 1982, and levels for the PM10 AAQS were selected
pursuant to California Code of Regulations Title 17 Section 70200 to protect the health of people
who are sensitive to exposure to fine particles; and
WHEREAS, research indicates that woodsmoke is a significant contributor to PM10 levels that
pose significant health risks; and
WHEREAS, the [] desires to lessen the risk to life and property from air
pollution from woodbuming appliances; and
WHEREAS, the [] finds that the proposed regulation will significantly reduce
the increase in particulate emissions from future installation and construction activities; and,
WHEREAS, the [] finds a need exists to adopt regulations which apply to
woodbuming combustionemissions; and
The [] Code shall be amended by adding the following:
Management District 9
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APPLICABILITY: This ordinance shall apply within the limits of the [city, county] of
[] as specified herein.
All wood burning appliances installed in new residential units or woodbuming appliances being
added to or replacing woodbuming appliances in existing residential units shall comply with this
ordinance.
All woodbuming appliances installed in new commercial buildings or woodbuming appliances
being added to or replacing woodbuming appliance in existing commercial buildings shall comply
with this ordinance. Commercial buildings shall include, but not be limited to, hotels and
restaurants.
Gas fireplaces shall be exempt from this ordinance. However, the conversion of a gas fireplace to
bum wood shall constitute the installation of a woodbuming appliance and shall be subject to the
requirements of this ordinance.
A woodbuming appliance shall comply with this ordinance if (1) it is reconstructed, (2) additions,
alterations, or repairs are made to the appliance that require opening up immediately-adjacent
walls, or (3) the residential unit or commercial building in which the appliance is located is
renovated, and the renovation includes opening up walls immediately adjacent to the appliance.
DEFINITIONS:
1."Bay Area Air Quality Management District" means the air quality agency for the San
Francisco Bay Area pursuant to California Health and Safety Code Section 40200.
2."E.P.A." means United States Environmental Protection Agency.
3."E.P.A. certified wood heater" means anywood heater that. meets the standards in Title 40,
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Bay Area Air (~
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Part 60, Subpart AAA, Code of Federal Regulations in effect at the time of installation and
is certified and labeled pursuant to those regulations.
"Fireplace" means any permanently installed masonry or factory-built woodbuming
appliance, except a pellet-fueled wood heater, designed to be used with an air-to-fuel ratio
greater than or equal to 35 to 1.
"Garbage means all solid, semi-solid and liquid wastes generated from residential,
commercial and industrial sources, including trash, refuse, rubbish, industrial wastes,
asphaltic products, manure, vegetable or animal sohds and semi-solid wastes, and other .
discarded solid and semi-solid wastes.
"Gas fireplace" means any device designed to burn natural gas in a manner that simulates
the appearance of a woodbuming fireplace.
"Paints" means all exterior and interior house and trim paints, enamels, varnishes, lacquers,
s.tains, primers, sealers, undercoatings, roof coatings, wood preservatives, shellacs, and
other paints or paint,like products.
"Paints solvents" means all original solvents sold or used to thin paints or to clean up
painting equipment.
"Pellet-fueled wood heater" means any woodbuming appliance that operates exclusively
on wood pellets.
"Solid fuel" means wood or any other non-gaseous or non-liquid fuel.
"Treated wood" means wood of any species that has been chemically impregnated, painted
or similarly modified to improve resistance to insects or weathering.
"Waste petroleum products" means any petroleum.product other than gaseous fuels that
has been refined from crude oil, and has been used, and as a result of use, has been
contaminated with physical or chemical impurities.
,Woodbuming appliance" means fireplace, wood heater, or pellet-fired wood heater or any
similar device burning any solid fuel used for aesthetic or space-heating purposes.
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Bay Area Air 0
GENERAL REQLHREMENTS: It shall be unlawful to:
1.Use any woodbuming appliance when the Bay Area Air Quality Management District
issues a "Spare the Air Tonight" warning and when an alternate approved heat source is
available.
2.Install a woodbttming appliance that is not one of the following: (1) a pellet-fueled wood
heater, (2) an EPA certified wood heater, or, (3) a fireplace certified by EPA should EPA
develop a fireplace certification program.
3.Use any of the following prohibited fuels in a woodbuming appliance.
a)Garbage g)Paint solvents
b)Treated wood h)Coal
c)Plastic products I)Glossy or colored papers
d)Rubber products j)Particle board
e)Waste pelroleum products k)Salt water drit~vcood
0 Paints
ENFORCEMENT: . Any person who plans to install a woodbuming appliance must submit
documentation to the [building department of city or county] demonstrating that the appliance is a
pellet-fueled wood heater, an EPA certified wood heater, or. a fireplace certified by EPA should
EPA develop a fireplace certification program.
Any person violating any of the provisions of this Ordinance shall be deemed guilty of a
misdemeanor and upon conviction shall be punishable as provided by, law.
IF ANY SECTION, subsection, sentence, clause or phrase or word of this ordinance is for any
reason held to be unconstitutional by a court of competent jurisdiction, such decision shall not
affect the validity of the remaining portions of this ordinance. The [] of
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Bay Area Air
the [] hereby declares that it would have passed and adopted this
ordinance and all provisions thereof irrespective of the fact that any one or more of said provision
be declared unconstitutional.
INTRODUCED and ordered Posted/Published this [
ADOPTED this [] day of [
AYES:
NOES:
ABSENT:
ABSTAIN:
] dayof [
], by the following vote:
ATTEST:APPROVED AS TO FORM:
p:\general\boardmemkmodord
ality Management District
BAY AREA
AIR O~ALITY
MANAGEMENT
DISTRICT Honorable Mayor Liz Kniss and City Council Members
City of Palo Alto
250 Hamilton Avenue
Palo Alto, CA 94301
Attachment C
’ April 21, 2000
Dear Mayor Kniss and Council members:
WOOD SMOKE AND YOUR HEALTH
The Bay Area Air Quality Management District has determined that an
aggressive public education campaign emphasizing benefits in reducing wood
smoke emissions in addition to implementation of restrictions on new
construction would result in positive benefits to the health and well-being of
the residents of Palo Alto. -
Give Palo Alto a healthy community. The adoption of the model ordinance on
wood smoke allows the public a wide range of choices including masonry
fireplaces with EPA certified inserts, gas-fired inserts or gas logs.
District staff is available to answer any additional questions that you may
have. Please call Thomasina Mayfield, Principal Air Quality Specialist, at
(415) 749-4774, if you have questions about the ordinance or these fact sheets.
15
939 ELLIS ’STREET ¯ SAN FRANCISCO CALIFORNIA 94109 ¯ 415.771.6000 ¯ www.baaqmd.gov
16
BAY AREA AIR QUALITY MANAGEMENT DISTRICT
FACT SH~EET - WOOD SMOKE MODEL ORDINANCE.
Why have a wood smoke ordinance?
January 2000
The Bay Area Air Quality Management District has encouraged local communities
to adopt ordinances to limit the building of new wood burning fireplaces and stoves. The
rationale is as follows:
(I)There is strong evidence that tiny airborne particles (f’me particulates) are a serious
health hazard, causing thousands of visits to hospital emergency rooms and
hundreds of premature deaths in the Bay Area alone.
(2)...Wood,burning.produces a large.fraction.of tlae.Bay.Area’s fme.particulate.in...
wintertime when high particulate levels occur.
The costs of reducing wood burning are far outweighed by the benefits. In fact, reducing
wood burning may be the single most cost-effective measure the Bay Area could take to
reduce air pollution and improve public health.
SpeciBc Questions
What follows are answers to specific questions to help clarify and support the
reasoning_behind wood burning_controls. Included are answers to many. of the qu.estions
raised by a letter from California Hearths and Homes (CH&H).I
Are all airborne particles harmful?
Some particles can cause allergic responses or cancer. There is good evidence,
however, that al! f’me particles can cause health problems, including aggravation Of asthma
and bronchitis, and even death. The evidence includes studies from all parts of the United
States and around the world that show consistent correlations between daily particle levels
and various health effects such as daily visits to hospital emergency rooms for respiratory
problems or daily deaths.
How serious is the problem?
The US EPA has. estimated that airborne particles cause 60,000 premature deaths
annually in the US. To put this in perspective, this is more people than died in auto
accidents -- about 40,000 annually.
i A letter was sent by California Hearths and Homes to members of the Palo Alto city council in December
questioning the need and efficacy of the District’s wood smoke ordinance.
Is there a-safe threshold?
At present, there is no definitive evidence for a threshold.
evidence that health effects occur even below current standards.
Moreover, there is
Are particle levels in the Bay Area safe?
A recently published study showed that there continued to be an association
between particulate levels and mortality in Santa Clara County ’.m the early 1990s, when
the Bay Area met all national air quality standards, including the standards for PM10 and
the new standard for PM2.5 (Falrley 1999).
A letter circulated by the California Hearth and Homes Association (CH&H) states
that "EPA standards suggest there is no PM10 public health threat," and "According to US
EPA standards, PMl0 levels in the Bay Area do not pose a threat to public health today, nor
have they for almost a decade." This is a bit disingenuous since the CH&H Association is
clearly aware that there is a stricter California PM~0 standard that is violated every year in
the Bay Area thereby suggesting that a health threat continues to the present. Moreover,
CH&H is either unaware, or chose to disregard, EPA’s new PM2.5 standards which are
stricter than its PM~0 standards and for which wood smoke is a larger contributor.
Is wood smoke a legitimate health concern in the Bay Area?
CH&H quotes BAAQMD’s Woodbuming Handbook to suggest that woodburning
releases "enough PMI0 into the atmosphere to be a legitimate public health coneern...only
rarely."
Days with levels exceeding the state standard occur 5 to 25 days per year even in
wet years. These figures double or triple in dry years. Wood smoke makes a substantial
contribution on most exeeedance days. On days exceeding the state standard, PM~0 levels
are elevated 25 ~tg/m3 or more above the norm. Based on the association between daily
mortality and particulate levels in Santa Clara County, it would increase the expected
number of deaths by about 5%, or about 1 death each day the state standard is exceeded.
Thus, wood smoke contributes to at least 5 to 25 deaths per year in Santa Clara
County.
What about the new national particulate standards?
In 1997, the US EPA established new standards for fine particulates. These are
particles with diameters of 2.5 microns or less (PM2.5). The new standard is meant largely
to supplant the older PM~0 as the primary particulate standard for.protecting public health..
The change was based on new evidence that fine particulates are a more serious health
concernthan larger "coarse" particulates.
How does wood smoke f~t in to the new standard?.
In general, fine particulates are caused by burning - mainly fossil fuels and
vegetative matter, whereas coarse particles are caused mainly by grinding processes -
producing dust from rocks, tires, brake linings, etc. In the Bay Area, dust is only a tiny
fraction of PM2.5. Thus combustion-produced partieulates,.ineluding wood smoke,
constitute a larger part of total PM2.~ than total P1V[t0.
What are the primary sources of fine particles in the Bay Area?
Based on chemical analysis of air filters, the major components of PM~0 include
ammonium nitrate (about 35%), wood smoke and cooking (about 34%), motor vehicle
exhaust and other fossil-fuel related emissions (12%), geological dust (12%), ammonium
sulfate (4%) and sea salt(2%). The figures sum to less that 100% due to rounding.
For PM2.5, the contributions from geologieal dust and sea salt are near zero, and the
contributions from the other sources comparably more. Wood smoke is essentially all
PM2.5.
Does wood smoke cont~bute significantly to particulate pollution in Santa Clara
County and the Bay Area generally?
Wood smoke is a ubiquitous problem in the wintertime air of the Bay Area, based
on analysis of air samples from around the Bay Area, along with other cortfirmatory
evidence. The fraction of PM~0 deriving from wood smoke ranges from 20% to 50%
among monitors spread around the Bay. In Santa Clara County, the fraction is at least 40%
and exceeds 50% on some nights, including nights where state and national standards are
violated.
CH&H stated that changes in fireplace design may account for some of decline in
PM~0 emissions. However, the data from 1998 show that woodsmoke remains a large
fraction of total PM~0 in the Bay Area.
How often does the Bay Area violate California PM~o standards?
In its critique of BAAQMD’s wood burning ordinance, CH&H stated that "Since
1989, the number of times the California [PM~0] standard has been exceeded has steadily
and dramatically decreased from a high of 51 calculated days in 1989 to a low of 3
calculated days in 1996."
This statement is not only misleading, it is also incorrect. It is incorrect because
particulates are not measured every day, but usually on a once-in-six-day schedule. Thus,
it is likely there were around 3x6 = 18 days when the state standards were exceeded in
1996. In eontrhst, in 1989, sampling at the District’s San Jose-4m St site (frequently the site
with the highest particulate readings among Bay Area monitoring sites) was on a once-in-
two-day schedule. Because the other sites were on a once-in-six-day schedule it is hard to
estimate the total number of excesses that would have occurred. One reasonable estimate
is 129 days.2
But comparing 1989 and 1996 also is misleading. High particulate levels occur
almost exclusively during the months of November through February, the middle of the
Bay Area’s rainy season. San Jose city rairffall was. only 7.7 inches in.1989, 3rd lowest in
the 49 years between 1949 and 1997, and barely half of the 14.2 inch normal. In contrast,
the rainfall in 1996 was 20.0 inches, 40% above normal. Particulate levels drop drastically
on rainy days, as common sense suggests. Thus, it is quite misleading to compare the
frequency of exceedances in the drought year like 1989 with a wet year like 1996.
Has there been a downtrend in particulate concentrations in the Bay Area?
Particulate concentrations depend heavily on the weather. Rainy days cut
particulate levels by 50% or more, as do days with high winds offthe ocean) The highest
Bay Area particulate levels occur during periods of winter stagnation, where polluted air
sits for long periods without being cleaned by rain or wind.
There indeed has been a dramatic decrease in particulate levels between 1989 and
the present. However, there has also been a dramatic increase in rainfall - from a drought
in 1989, to the winter of 1997-98, the wettest in the 20t~ century in San Francisco. This
makes it very difficult to determine how much of the decrease in particulate levels is due to
increased rainfall and how much is due to reductions in particulate emissions. Our
Emissions Inventory shows no reduction in direct PM~0 emissions over this period. EPA
estimates that on a national level PM~0 has fallen by about 25% in the past decade.
Does wood burning contribute to or cause air quality standards to be exceeded?.
There is good evidence that wood smoke not only frequently contributes to
exceedances of state and national standards, but occasionally would cause exceedances
even without any other source of particles being present.
For example, the highest PMI0 concentration in San Jose during 1998 was 92 p.g/m3
on December 25, that is, Christmas day. Based on measurements of a component of PM~0
that is a marker for wood smoke, namely soluble potassium, the level of wood smoke alone
would probably have been enough to cause an exceedance.
In 1999, the 2"a and 3ra highest PM2.5 readings in San Jose occurred on December
24t~ and 26m, again, very likely due mainly to wood smoke. Both of these readings
2 The calculation is as follows; San Jose-4t~ St registered 42 excesses in. 178 monitored days spread evenly
throughout 1989. Thus, if every day had been sampled, it would have registered exceedances on
approximately 42 x (365/178) = 86 days. Among the days when other District sites were operating, there
were 7 days were another District site measured an exceedance and the S J-4~ St monitor didn’t. Thus, there
should be approximately an additional 7 x (365/60) = 43 days with exceedances, for a total of 86 + 43 = 129
days.3 In the Bay Area,- high particulate levels rarely occur on windy days. In the winter, there is a strong-inverse
relationship between wind and particulate l.evels, that is, high winds almost always bring low particulate
levels.
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exceeded the national PM2.5 standard. (Interestingly, the highest measured PM2.5 level
occurred on October 21 st, during a period when wildfires were burning around the state.)
Ho~" do we know that a large portion of the particulates in the Bay Area come from
wood burning?
CH&H questions whether the methodology for determining the fraction of
particulates from wood smoke is valid, stating that "the ’scientific’ basis for the ordinance
is nearly a decade old - relying on ... readings from only two of the Bay Area’s 17
pollution monitors - two monitors located in San Jose..."
Let’s take the second point ftrst.- The study referred to by CH&H was a pilot study
done in the winter of 1991-92, It was just the first of several studies. A more
comprehensive study was performed from November of 1992 through February of 1994.
In the winter of 1993-94, data from four widely differing sites - San Francisco, Livermore,
Bethel Island, and San Jose - were analyzed. In it we found evidence for wood smoke at
each of the sites, with contributions ranging from 20% of PM~0 for SanFrancisco to 30%
for Bethel Island and 40% for San Jose and Livermore.
Starting in 1995, the District began monitoring for soluble potassium at 16 Bay
Area sites. Soluble potassium is a chemical marker for wood smoke; although it occurs in
othe.r.eompo -tmdsc~ommonty..found.in.the. air.of.the Bay..Area~. soluble potassium.represents-
a much larger fraction in wood smoke. Using this marker, and filtering out the
eonta’ibution from other compounds, we determined that wood smoke is a major
contributor to wintertime PM~0 at all 16 locations, ranging from 20% for San Francisco to
50% for Napa. Monitoring for soluble potassium continues and, based on the latest
availableevidenee;-these-pereentages-are stillvalid: .....
Thus, our evidence for the presence of wood smoke is much more recent and
comprehensive than CH&H claims.
Dr. David Fairley
References
BAAQMD 1997, Letter with comments to EPA regarding the new standard, Bay Area Air
Quality Management District, March 7; 1997.
Dockery, DW, A Pope III, X Xiping, JD Spengler, JI-I Ware, ME Fay, BG Farris, and FE
Speizer. "An association between air pollution and mortality in six U.S. cities," New
England Journal of Medicine, 329:1753-1759, 1999/12/3.
Fairley, D. "Daily air pollution and mortality in Santa Clara, California: 1989-1996,"
Environmental-Health.Perspectives Vol.--107; #8, A~agust;- t-999~ .....
NORTHERN
COUNTY
POLLUTION CONTROL DISTRICT
150 Matheson Street, Healdsburg, CA 95448
Ms. Teresa Lee, Director
Public Information and Education
Bay Area Air Quality Management District
939 Ellis Street
San Francisco, CA
PH: (707) 433-5911 ¯FX: (707)
February 7, 2000
433-4823
Dear Ms. Lee,
This letter is in response to your inquiries about our wood smoke program as it currently relates
to masonry fireplace installations. At this time the District has not certified any wood fired
masonry fireplace system for use in our District. However, there still is a demand for these
fireplace systems based upon the intrinsic architectural value placed on them by some
homeowners and businesses (such as wineries and restaurants). Happily, we have identified a
compromise solution, utilizing natural gas or propane fuels, that satisfies the needs of those who
would like to have a masonry fireplace, without compromising air quality or public health goals.
Because of the advancements made in the construction, appearance and performance of modem
gas log systems we have found that the owners are generally pleasantly surprised by the end
results..
Masonry fireplaces can be constructed and operated in our District with permanent, dedicated,
gas fueled "log" systems. These fireplaces are approved for installation at the time of plan check
submittal provided the owner provides a written, notarized certification to us that the gas log
installation will not be removed after final inspection. We require that the stamped blueprints
include notes to this effect.. The owner certification includes a statement that the owner
acknowledgesthat removal of said system and operation of the fireplace with a solid fuel is a.
violation of the applicable local ordinance. The affidavit must also include a commitment to
disclose to any future property owner the terms of this agreement in the event of a sale. The
compromise is administratively simple, easy to field verify, and has worked well.
We appreciate the cooperation and assistance your office has provided to us over the years, and
we are happy to be able to provide this information in kind. If you have any questions about our
programs please feel free to contact me or,. MrI George E~f....
S°
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