[Federal Register Volume 64, Number 12 (Wednesday, January 20, 1999)]
[Rules and Regulations]
[Pages 3030-3037]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-1125]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 58
[AD-FRL-6221-2]
RIN 2060-AF71
Ambient Air Quality Surveillance for Lead
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: Lead air pollution levels measured near the Nation's roadways
[[Page 3031]]
have decreased 97 percent between 1978 and 1997 with the elimination of
lead in gasoline used by on-road mobile sources. Because of this
historic decrease, EPA is reducing its requirements for measuring lead
air pollutant concentrations near major highways, while retaining its
focus on point sources and their impact on neighboring populations. The
EPA published a direct final rule for ambient air quality surveillance
for lead on November 5, 1997 (62 FR 59813). Due to adverse comments
received, the rule was withdrawn on December 23, 1997 (62 FR 67009).
Based on comments that were received, today's action revises 40 CFR
part 58 lead air monitoring regulations to allow many lead monitoring
stations to be discontinued while maintaining a core lead monitoring
network in urban areas to track continued compliance with the lead
National Ambient Air Quality Standards (NAAQS). This action does not
diminish existing requirements for lead ambient air monitoring around
lead point sources. Approximately 70 of the National Air Monitoring
Stations (NAMS) and a number of the State and Local Air Monitoring
Stations (SLAMS) could be discontinued with this action, thus making
more resources available to those State and local agencies to deploy
lead air quality monitors around heretofore unmonitored lead point
sources. Affected industries include primary and secondary lead
smelting, lead battery recycling, and primary copper smelting.
DATES: The effective date of this rule is February 19, 1999.
ADDRESSES: All comments relative to this rule have been placed in
Docket No. A-91-22, located in the Air Docket (LE-131), U.S.
Environmental Protection Agency, 401 M Street, SW, Washington, DC
20460. The docket may be inspected between 8 a.m. and 5:30 p.m., Monday
through Friday, excluding legal holidays. A reasonable fee may be
charged for copying.
FOR FURTHER INFORMATION CONTACT: For general information, contact
Brenda Millar, Emissions, Monitoring, and Analysis Division (MD-14),
Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711,
Telephone: (919) 541-4036, e-mail: millar.brenda@epa.gov. For technical
information, contact Michael Jones, Emissions Monitoring, and Analysis
Division (MD-14), Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711, Telephone: (919) 541-0528, e-mail: jones.mike@epa.gov.
SUPPLEMENTARY INFORMATION:
I. Authority
Sections 110, 301(a), and 319 of the Clean Air Act as amended 42
U.S.C. 7410, 7601(a), 7619.
II. Background
The current ambient air monitoring regulations that pertain to lead
air sampling were written in the 1970's when lead emissions from on-
road mobile sources (e.g., automobiles, trucks) were the predominant
lead air emission source affecting our communities. As such, the
current lead monitoring requirements focus primarily upon the idea of
determining the air quality impacts from major roadways and urban
traffic arterial highways. Since the 1970's, lead has been removed from
gasoline sources for on-road vehicles (on-road vehicles now account for
less than 1 percent of total lead emissions), and a 97 percent decrease
in lead air pollution levels measured in our neighborhoods and near
roadways has occurred nationwide. Because of this historic decrease,
EPA is reducing its requirements for measuring lead air pollutant
concentrations near major highways, while retaining its focus on point
sources and their impacts on neighboring populations.
Several commenters observed that the rule's assessment of on-road
vehicles emissions is contrary to the Agency's own figures.
Specifically, the proposed rule stated that on-road vehicle emissions
account for less than 1 percent of total lead emissions, while the
Agency's 1995 National Air Quality and Emissions Trends Report (EPA
454/R-96-005) indicated that nearly 28 percent of total air lead
emissions were attributable to on-road vehicles.
Based on the emissions reported in ``Locating and Estimating Air
Emissions from Sources of Lead and Lead Compounds'' (Eastern Research
Group, Draft Report, July 1996), on-road vehicle emissions had been
over estimated. The EPA investigated this inconsistency and found due
cause to revise on-road vehicle emissions estimates. These revisions
are reflected in subsequent Agency reports (e.g., EPA 454/R-97-011,
``National Air Pollutant Emission Trends, 1900-1996'', EPA 454/R-97013,
``National Air Quality and Trends Report, 1996,'' and EPA 454/R-98-016,
``National Air Quality and Trends Report, 1997'') wherein on-road
vehicle emissions are listed as contributing approximately 0.5 percent
of the total lead estimate.
Several commenters questioned the rule's asserted need for
additional monitors around stationary point sources, particularly the
basis for increased scrutiny of stationary sources emitting five or
more tons per year, as well as, in select cases, those sources emitting
less than 5 tons per year. Further, the potential for increased
information collection burden, and means of determining which ``smaller
stationary sources'' would be considered ``problematic'' were also
questioned.
The primary objective of this rule is to reduce the requirement for
lead air pollutant concentration measurements near major highways,
while maintaining a focus on lead point sources and their impact on
neighboring populations. The EPA has determined that, in the interest
of furthering attainment of the National Ambient Air Quality Standard
(NAAQS) for lead, it is prudent for State and local agencies to deploy
these additional lead monitoring resources in the vicinity of any
previously unmonitored point source which they feel may have the
potential to cause lead air quality violations. A point source is
defined in 40 CFR 51.100(k)(2) as ``For lead or lead compounds measured
as lead, any stationary source that actually emits a total of 4.5
metric tons (5 tons) per year or more.'' Though the verbiage `` * * *
although smaller stationary sources may also be problematic depending
upon the facility's size and proximity to neighborhoods' was removed
from this rule, State and local agencies are not precluded from further
evaluating any lead source which they feel may have the potential to
violate lead air quality standards. Suggested guidelines for such
source evaluations are described in ``Screening Procedures for
Estimating the Air Quality Impact of Stationary Sources, Revised'' (EPA
454/R-92-019). Finally, ambient lead monitoring occurs at existing
major primary and secondary lead smelters, lead acid battery plants,
and primary copper smelters. As essentially all quantifiable lead point
sources are included in these categories, and considering the
substantial decrease in roadside monitoring which will result from this
rule, EPA believes this rule will entail little or no increased
information collection burden.
A State requested that EPA amend the referenced rule to delete the
requirement for one NAMS population-oriented site in the vicinity of a
specific facility within their jurisdiction.
The monitoring site north of the facility in question has reported
lead NAAQS violations in 1 or 2 quarters during each of the past 3
years. Given that this monitor is sited at the middle
[[Page 3032]]
scale, it is not unreasonable to require a NAMS site on the
neighborhood scale. Data from such a site are useful in representing
typical air quality values for nearby residential areas, and suitable
for population exposure and trends analysis.
The current lead air monitoring regulations require that each
urbanized area with a population of 500,000 or more operate at least
two lead NAMS, one of which must be a roadway-oriented site and the
second must be a neighborhood site with nearby traffic arteries or
other major roadways. There are approximately 58 NAMS in operation and
reporting data for 1998. This action would change this NAMS requirement
to include one NAMS site in one of the two largest Metropolitan
Statistical Areas (MSA/CMSA) within each of the ten EPA Regions, and
one NAMS population-oriented site in each populated area (either a MSA/
CMSA, town, or county) where lead violations have been measured over
the most recent 8 calendar quarters. This latter requirement is
designed to provide information to citizens living in areas that have
one or more lead point sources that are causing recent air quality
violations. At present, the MSA/CMSAs, cities, or counties that have
one or more quarterly Pb NAAQS violations that may be subject to this
requirement are listed in Table 1.
Table 1.--CMSA/MSA's or Counties With One or More Lead NAAQS Violations
in 1996-1997
------------------------------------------------------------------------
CMSA/MSA or County Contributing Lead Source(s)
------------------------------------------------------------------------
Philadelphia-Wilmington-Atlantic City Franklin Smelter in
CMSA. Philadelphia County, PA.
Tampa-St. Petersburg-Clearwater MSA.... Gulf Coast Lead in Hillsborough
County, FL.
Memphis MSA............................ Refined Metals in Shelby
County, TN.
Nashville MSA.......................... General Smelting in Williamson
County, TN.
St. Louis MSA.......................... Chemetco in Madison County, IL,
and Doe Run in Jefferson
County, MO.
Cleveland-Akron CMSA................... Master Metals in Cuyahoga
County, OH.
Iron County, MO........................ ASARCO in/near Hogan, MO.
Omaha MSA.............................. ASARCO in Douglas County, NE.
Lewis and Clark County, MT............. ASARCO in/near East Helena, MT.
------------------------------------------------------------------------
Data from these NAMS will be used to assess national trends in lead
ambient air pollution. Figure 1 demonstrates the effect that these
monitoring reductions will have on our national lead air pollutant
trends.
[GRAPHIC] [TIFF OMITTED] TR20JA99.001
For other monitoring within the SLAMS network, EPA is allowing
State and local agencies to further focus their efforts toward
establishing air monitoring networks around lead point sources which
are causing or have a potential to cause exceedances of the quarterly
lead NAAQS. Many of these sources have been identified through EPA's
ongoing Lead NAAQS Attainment Strategy, and monitoring has already been
established. All point sources (stationary sources emitting five or
more tons per year) are considered to be candidates for additional lead
monitoring . The EPA recommends a minimum of two sites per source, one
located for stack emission impacts and the other for fugitive emission
impacts. Variations of this two-site network are expected as source
type, topography,
[[Page 3033]]
locations of neighboring populations, and other factors play a role in
how to most appropriately design such a network. EPA guidance for lead
monitoring around point sources has been developed and is available
through a variety of sources including the National Technical
Information Service (800-553-6847), and electronic forms accessible
through EPA's Office of Air Quality Planning & Standards Technology
Transfer Network, Ambient Monitoring Technology Information Center
(AMTIC) bulletin board system at http://ttnwww.rtpnc.epa.gov.
One commenter questioned the rule's consistency with statutory
mandates under section 319 of the Clean Air Act (CAA), in particular by
citing the requirement for ``uniform air quality criteria * * *
throughout the United States.'' 42 U.S.C. 7619.
In section 319 of the CAA, the term ``criteria'' refers to a
specific set of pollutants and the associated levels and forms of their
respective standards. The term ``uniform'' refers to both criteria and
measurement methodology, relative to a specific air quality index.
Uniformity in ambient monitoring is achieved by monitor design
specifications (40 CFR part 53) and quality assurance/quality control
procedures. Monitors which meet such design specifications are
designated as either Federal Reference Method (FRM) or Federal
Equivalent Method (FEM), as appropriate. Further, upon reading the
entire text of the CAA, section 319, from which the commenter's excerpt
was taken, it becomes clear that the new rule is, in fact, consistent
with the referenced statutory mandates.
Several commenters noted that this rule is being issued in response
to numerous State and local agency requests, yet the docket contains no
documentation of such requests.
As many roadside monitored ambient lead values have steadily
declined to at or near minimally detectable levels, the need for
continued roadside ambient lead monitoring has been increasingly and
repeatedly questioned by State representatives at the biannual Standing
Air Monitoring Work Group meetings, as well as several instances of
written queries and requests. The reason the Agency did not include any
such existing documentation in the docket is that the basis for this
rule revision is not requests from State and local agencies, but rather
EPA's success in essentially eliminating on-road mobile source lead
emissions. Given the fact that on-road mobile sources' contribution to
the total lead emissions estimate is negligible, as evidenced by
minimally detectable ambient levels at all locations other than sites
in proximity to lead point sources, it is EPA's inherent responsibility
to ensure our nation's ambient air pollution monitoring resources are
redirected toward environmental issues of concern.
Several commenters expressed concern over potential data misuse in
commencement of unjustified enforcement proceedings or citizen suits.
The reason for concern was cited as the combined impact of the proposed
revisions to 40 CFR part 58 and EPA's Credible Evidence revisions to 40
CFR parts 51, 52, 60, and 61.
The referenced Credible Evidence revisions and related amendments
to 40 CFR part 64, Compliance Assurance Monitoring, pertain exclusively
to emissions monitoring data, not ambient air quality data. The
proposed revisions to 40 CFR part 58, Ambient Air Quality Surveillance,
do not allow for use of non-reference data in any compliance or
enforcement actions. There is, therefore, no plausible potential for
data misuse in commencement of unjustified enforcement proceedings or
citizen suits.
In addition to the changes to the lead monitoring requirements, EPA
is making several minor changes to update and correct regulatory
provisions to current practices. Specifically this affects Secs. 58.31,
58.34, 58.41, Appendix B, Appendix D Sections 3.2 and 3.3, and Appendix
G, Sections 1 and 2b.
III. Administrative Requirements
A. Executive Order 12866
Under Executive Order 12866 (58 F.R. 51735, October 4, 1993), the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to Office of Management and Budget (OMB) review
and to the requirements of the Executive Order. The Order defines
``significant regulatory action'' as one that is likely to result in a
rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or governments or communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another Agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
It has been determined that this action is not a ``significant
regulatory action'' under the terms of the Executive Order 12866 and is
therefore not subject to formal OMB review.
B. Paperwork Reduction Act
Today's action does not impose any new information collection
burden. This action revises the part 58 air monitoring regulations for
lead to allow many monitoring sites to be discontinued. The Office of
Management and Budget (OMB) has previously approved the information
collection requirements in the part 58 regulation under the provisions
of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned
OMB control number 2060-0084 (EPA ICR No. 0940.13 and revised by
0940.14).
C. Executive Order 12875 Enhancing the Intergovernmental Partnership
Under Executive Order 12875, EPA may not issue a regulation that is
not required by statute and that creates a mandate upon a State, local
or tribal government, unless the Federal government provides the funds
necessary to pay the direct compliance costs incurred by those
governments, or EPA consults with those governments. If EPA complies by
consulting, Executive Order 12875 requires EPA to provide to the Office
of Management and Budget a description of the extent of EPA's prior
consultation with representatives of affected State, local and tribal
governments, the nature of their concerns, copies of any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, Executive Order 12875
requires EPA to develop an effective process permitting elected
officials and other representatives of State, local and tribal
governments ``to provide meaningful and timely input in the development
of regulatory proposals containing significant unfunded mandates.''
Today's rule implements requirements specifically set forth by the
Congress in 42 U.S.C. 7410 without the exercise of any discretion by
EPA. Accordingly, the requirements of section 1(a) of Executive Order
12875 do not apply to this rule.
D. Executive Order 13045
Executive Order 13045, entitled ``Protection of Children from
Environmental Health Risks and Safety Risks'' (62 FR 19885, April 23,
1997), applies to any rule that the EPA determines (1) is
``economically significant,'' as defined under Executive Order 12866,
and (2) the environmental
[[Page 3034]]
health or safety risk addressed by the rule has a disproportionate
effect on children. If the regulatory action meets both criteria, the
Agency must evaluate the environmental health or safety effects of the
planned rule on children and explain why the planned regulation is
preferable to other potentially effective and reasonably feasible
alternatives considered by the Agency.
This rule is not subject to Executive Order 13045 because it is not
an economically significant regulatory action as defined by Executive
Order 12866, and it does not address an environmental health or safety
risk that would have a disproportionate effect on children.
E. Executive Order 13084 Consultation and Coordination With Indian
Tribal Governments
Under Executive Order 13084, EPA may not issue a regulation that is
not required by statute, that significantly or uniquely affects the
communities of Indian tribal governments, and that imposes substantial
direct compliance costs on those communities, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by the tribal governments, or EPA consults with those
governments. If EPA complies by consulting, Executive Order 13084
requires EPA to provide to the Office of Management and Budget, in a
separately identified section of the preamble to the rule, a
description of the extent of EPA's prior consultation with
representatives of affected tribal governments, a summary of the nature
of their concerns, and a statement supporting the need to issue the
regulation. In addition, Executive Order 13084 requires EPA to develop
an effective process permitting elected officials and other
representatives of Indian tribal governments ``to provide meaningful
and timely input in the development of regulatory policies on matters
that significantly or uniquely affect their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. Accordingly, the requirements
of section 3(b) of Executive Order 13084 do not apply to this rule.
F. Impact on Small Entities
The Regulatory Flexibility Act (RFA) generally requires an agency
to conduct a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements unless the agency certifies
that the rule will not have a significant economic impact on a
substantial number of small entities. Small entities include small
businesses, small not-for-profit enterprises, and small governmental
jurisdictions whose jurisdictions are less than 50,000 people. This
rule will not have a significant impact on a substantial number of
small entities because it does not impact small entities whose
jurisdictions cover less than 50,000 people. Pursuant to the provision
of 5 U.S.C. 605(b), I certify that this action will not have a
significant economic impact on a substantial number of small entities.
Since this modification is classified as minor, no additional
reviews are required.
G. Unfunded Mandates Reform Act of 1995
Under section 202 of the Unfunded Mandates Reform Act of 1995
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA
must prepare a budgetary impact statement to accompany any proposed or
final standards that include a Federal mandate that may result in
estimated costs to State, local, or tribal governments, or to the
private sector, of, in the aggregate, $100 million or more. Under
section 205, the EPA must select the most cost-effective and least
burdensome alternative that achieves the objectives of the standard and
is consistent with statutory requirements. Section 203 requires EPA to
establish a plan for informing and advising any small governments that
may be significantly or uniquely impacted by the standards. The EPA has
determined that this action does not include a Federal mandate that may
result in estimated costs of $100 million or more to either State,
local, or tribal governments. Therefore, the requirements of the
Unfunded Mandates Act of 1995 do not apply to this action.
H. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Pub. L. No. 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. The NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.
This action does not involve technical standards. Therefore, EPA
did not consider the use of any voluntary consensus standards.
I. Submission to Congress and the General Accounting Office
The Congressional Review Act, U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the Agency promulgating
the rule must submit a rule report, which includes a copy of the rule
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. This rule is not a
``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 58
Environmental protection, Air pollution control, Intergovernmental
relations, Reporting and recordkeeping requirements, Quality assurance
requirements, Ambient air quality monitoring network.
Dated: January 12, 1999.
Carol M. Browner,
Administrator.
For the reasons set forth in the preamble, title 40, chapter I,
part 58 of the Code of Federal Regulations is amended as follows:
PART 58--[AMENDED]
1. The authority citation for part 58 continues to read as follows:
Authority: 42 U.S.C. 7410, 7601(a), 7613, 7619.
2. Section 58.31(a) is revised to read as follows:
Sec. 58.31 NAMS network description.
* * * * *
(a) The AIRS site identification number for existing stations.
* * * * *
3. Section 58.34(a) is revised to read as follows:
Sec. 58.34 NAMS network completion.
* * * * *
(a) Each NAMS must be in operation, be sited in accordance with the
criteria in Appendix E to this part, and be located as described in the
AIRS database; and
* * * * *
[[Page 3035]]
4. Section 58.41(b) is revised to read as follows:
Sec. 58.41 PAMS network description.
* * * * *
(b) The AIRS site identification number for existing stations.
* * * * *
5. Appendix D is amended by revising the first sentence of the
undesignated paragraph following paragraph (6) of section 1, revising
section 2.7, revising the fifth paragraph of section 3, revising the
last sentence of the first paragraph of section 3.2, revising the last
sentence of the first paragraph of section 3.3, revising section 3.6,
and revising references 6, 7, 10 of section 6 and adding reference 19
to section 6 to read as follows:
Appendix D--Network Design for State and Local Air Monitoring
Stations (SLAMS), National Air Monitoring Stations (NAMS), and
Photochemical Assessment Monitoring Stations (PAMS)
* * * * *
1. SLAMS Monitoring Objectives and Spatial Scales
* * * * *
It should be noted that this appendix contains no criteria for
determining the total number of stations in SLAMS networks, except
in areas where Pb concentrations currently exceed or have exceeded
the Pb NAAQS during any one quarter of the most recent eight
quarters. * * *
* * * * *
2.7 Lead (Pb) Design Criteria for SLAMS. Presently, less than 1
percent of the Nation's Pb air pollution emissions originate from
on-road mobile source exhaust. The majority of Pb emissions come
from point sources, such as metals processing facilities, waste
disposal and recycling, and fuel combustion (reference 19 of this
appendix). The SLAMS networks are used to assess the air quality
impacts of Pb point sources, and to determine the broad population
exposure from any Pb source. The most important spatial scales to
effectively characterize the emissions from point sources are the
micro, middle, and neighborhood scales. For purposes of establishing
monitoring stations to represent large homogeneous areas other than
the above scales of representativeness, urban or regional scale
stations may also be needed.
Microscale--This scale would typify areas in close proximity to
lead point sources. Emissions from point sources such as primary and
secondary lead smelters, and primary copper smelters may under
fumigation conditions likewise result in high ground level
concentrations at the microscale. In the latter case, the microscale
would represent an area impacted by the plume with dimensions
extending up to approximately 100 meters. Data collected at
microscale stations provide information for evaluating and
developing ``hot-spot'' control measures.
Middle Scale--This scale generally represents Pb air quality
levels in areas up to several city blocks in size with dimensions on
the order of approximately 100 meters to 500 meters. The middle
scale may for example, include schools and playgrounds in center
city areas which are close to major Pb point sources. Pb monitors in
such areas are desirable because of the higher sensitivity of
children to exposures of elevated Pb concentrations (reference 7 of
this appendix). Emissions from point sources frequently impact on
areas at which single sites may be located to measure concentrations
representing middle spatial scales.
Neighborhood Scale--The neighborhood scale would characterize
air quality conditions throughout some relatively uniform land use
areas with dimensions in the 0.5 to 4.0 kilometer range. Stations of
this scale would provide monitoring data in areas representing
conditions where children live and play. Monitoring in such areas is
important since this segment of the population is more susceptible
to the effects of Pb. Where a neighborhood site is located away from
immediate Pb sources, the site may be very useful in representing
typical air quality values for a larger residential area, and
therefore suitable for population exposure and trends analyses.
Urban Scale--Such stations would be used to present ambient Pb
concentrations over an entire metropolitan area with dimensions in
the 4 to 50 kilometer range. An urban scale station would be useful
for assessing trends in citywide air quality and the effectiveness
of larger scale air pollution control strategies.
Regional Scale--Measurements from these stations would
characterize air quality levels over areas having dimensions of 50
to hundreds of kilometers. This large scale of representativeness,
rarely used in Pb monitoring, would be most applicable to sparsely
populated areas and could provide information on background air
quality and inter-regional pollutant transport.
Monitoring for ambient Pb levels is required for all major
urbanized areas where Pb levels have been shown or are expected to
be of concern due to the proximity of Pb point source emissions.
Sources emitting five tons per year or more of actual point and
fugitive Pb emissions would generally be candidates for lead ambient
air monitoring. Modeling may be needed to determine if a source has
the potential to exceed the quarterly lead National Ambient Air
Quality Standards (NAAQS). The total number and type of stations for
SLAMS are not prescribed but must be determined on a case-by-case
basis. As a minimum, there must be two stations in any area where Pb
concentrations currently exceed or have exceeded the Pb NAAQS during
any one quarter of the most recent eight quarters. Where the Pb air
quality violations are widespread or the emissions density,
topography, or population locations are complex and varied, there
may be a need to establish more than two Pb ambient air monitoring
stations. The EPA Regional Administrator may specify more than two
monitoring stations if it is found that two stations are
insufficient to adequately determine if the Pb standard is being
attained and maintained. The Regional Administrator may also specify
that stations be located in areas outside the boundaries of the
urbanized areas.
Concerning the previously discussed required minimum of two
stations, at least one of the stations must be a category (a) type
station and the second may be either category (a) or (b) depending
upon the extent of the point source's impact and the existence of
residential neighborhoods surrounding the source. When the source is
located in an area that is subject to NAMS requirements as in
Section 3 of this Appendix, it is preferred that the NAMS site be
used to describe the population's exposure and the second SLAMS site
be used as a category (a) site. Both of these categories of stations
are defined in section 3.
To locate monitoring stations, it will be necessary to obtain
background information such as point source emissions inventories,
climatological summaries, and local geographical characteristics.
Such information should be used to identify areas that are most
suitable to the particular monitoring objective and spatial scale of
representativeness desired. References 9 & 10 of this appendix
provide additional guidance on locating sites to meet specific urban
area monitoring objectives and should be used in locating new
stations or evaluating the adequacy of existing stations.
After locating each Pb station and, to the extent practicable,
taking into consideration the collective impact of all Pb sources
and surrounding physical characteristics of the siting area, a
spatial scale of representativeness must be assigned to each
station.
* * * * *
3. Network Design for National Air Monitoring Stations (NAMS)
* * * * *
For each urban area where NAMS are required, both categories of
monitoring stations must be established. In the case of Pb and
SO2 if only one NAMS is needed, then category (a) must be
used. The analysis and interpretation of data from NAMS should
consider the distinction between these types of stations as
appropriate.
* * * * *
3.2 Sulfur Dioxide Design Criteria for NAMS
* * * The actual number and location of the NAMS must be
determined by EPA Regional Offices and the State Agency, subject to
the approval of EPA Headquarters, Office of Air Quality Planning and
Standards (OAQPS).
* * * * *
3.3 Carbon Monoxide (CO) Design Criteria for NAMS
* * * At the national level, EPA will not routinely require data
from as many stations as are required for PM-10, and perhaps
SO2, since CO trend stations are principally needed to
assess the overall air quality progress resulting from the emission
controls required by the Federal motor vehicle control program
(FMVCP) and other local controls.
* * * * *
[[Page 3036]]
3.6 Lead (Pb) Design Criteria for NAMS. In order to achieve the
national monitoring objective, one NAMS site must be located in one
of the two cities with the greatest population in the following ten
regions of the country (the choice of which of the two metropolitan
areas should have the lead NAMS requirement is made by the
Administrator or the Administrator's designee using the
recommendation of the Regional Administrators or the Regional
Administrators' designee):
Table 1.--EPA Regions & Two Current Largest MSA/CMSAs (Using 1995 Census
Data)
------------------------------------------------------------------------
Region (States) Two Largest MSA/CMSAs
------------------------------------------------------------------------
I (Connecticut, Massachusetts, Maine, Boston-Worcester-Lawrence CMSA,
New Hampshire, Rhode Island, Vermont). Hartford, CT MSA.
II (New Jersey, New York, Puerto Rico, New York-Northern New Jersey-
U.S. Virgin Islands). Long Island, CMSA, San Juan-
Caguas-Arecibo, PR CMSA.
III (Delaware, Maryland, Pennsylvania, Washington-Baltimore CMSA,
Virginia, West Virginia, Washington, Philadelphia-Wilmington-
DC). Atlantic City CMSA.
IV (Alabama, Florida, Georgia, Miami-Fort Lauderdale CMSA,
Kentucky, Mississippi, North Carolina, Atlanta, GA MSA.
South Carolina, Tennessee).
V (Illinois, Indiana, Michigan, Chicago-Gary-Kenosha CMSA,
Minnesota, Ohio, Wisconsin). Detroit-Ann Arbor-Flint CMSA.
VI (Arkansas, Louisiana, New Mexico, Dallas-Fort Worth CMSA, Houston-
Oklahoma, Texas). Galveston-Brazoria CMSA.
VII (Iowa, Kansas, Missouri, Nebraska). St. Louis MSA, Kansas City MSA.
VIII (Colorado, Montana, North Dakota, Denver-Boulder-Greeley CMSA,
South Dakota, Utah, Wyoming). Salt Lake City-Ogden MSA.
IX (American Samoa, Arizona, Los Angeles-Riverside-Orange
California, Guam, Hawaii, Nevada). County CMSA, San Francisco-
Oakland-San Jose CMSA.
X (Alaska, Idaho, Oregon, Washington).. Seattle-Tacoma-Bremerton CMSA,
Portland-Salem CMSA.
------------------------------------------------------------------------
In addition, one NAMS site must be located in each of the MSA/
CMSAs where one or more violations of the quarterly Pb NAAQS have
been recorded over the previous eight quarters. If a violation of
the quarterly Pb NAAQS is measured at a monitoring site outside of a
MSA/CMSA, one NAMS site must be located within the county in a
populated area, apart from the Pb source, to assess area wide Pb air
pollution levels. These NAMS sites should represent the maximum Pb
concentrations measured within the MSA/CMSA, city, or county that is
not directly affected from a single Pb point source. Further, in
order that on-road mobile source emissions may continue to be
verified as not contributing to lead NAAQS violations, roadside
ambient lead monitors should be considered as viable NAMS site
candidates. A NAMS site may be a microscale or middle scale category
(a) station, located adjacent to a major roadway (e.g., >30,000
ADT), or a neighborhood scale category (b) station that is located
in a highly populated residential section of the MSA/CMSA or county
where the traffic density is high. Data from these sites will be
used to assess general conditions for large MSA/CMSAs and other
populated areas as a marker for national trends, and to confirm
continued attainment of the Pb NAAQS. In some cases, the MSA/CMSA
subject to the latter lead NAMS requirement due to a violating point
source will be the same MSA/CMSA subject to the lead NAMS
requirement based upon its population. For these situations, the
total minimum number of required lead NAMS is one.
* * * * *
6. References
* * * * *
6. Lead Guideline Document, U. S. Environmental Protection
Agency, Research Triangle Park, NC. EPA-452/R-93-009.
7. Air Quality Criteria for Lead. Office of Research and
Development, U.S. Environmental Protection Agency, Washington, DC.
EPA-600/8-83-028 aF-dF, 1986, and supplements EPA-600/8-89/049F,
August 1990. (NTIS document numbers PB87-142378 and PB91-138420.)
* * * * *
10. ``Guidance for Conducting Ambient Air Monitoring for Lead
Around Point Sources,'' Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, Research Triangle
Park, NC EPA-454/R-92-009, May 1997.
* * * * *
19. National Air Pollutant Emissions Trends, 1900-1995, Office
of Air Quality Planning and Standards, U. S. Environmental
Protection Agency, Research Triangle Park, NC. EPA-454/R96-007,
October 1996, updated annually.
6. Appendix E is amended by revising the first paragraph of section
7.1, adding a sentence at the beginning of section 7.3, revising
section 7.4, and revising reference 18 in section 13 to read as
follows:
Appendix E--Probe and Monitoring Path Siting Criteria for Ambient
Air Quality Monitoring
* * * * *
7.1 Vertical Placement. Optimal placement of the sampler inlet
for Pb monitoring should be at breathing height level. However,
practical factors such as prevention of vandalism, security, and
safety precautions must also be considered when siting a Pb monitor.
Given these considerations, the sampler inlet for microscale Pb
monitors must be 2-7 meters above ground level. The lower limit was
based on a compromise between ease of servicing the sampler and the
desire to avoid unrepresentative conditions due to re-entrainment
from dusty surfaces. The upper limit represents a compromise between
the desire to have measurements which are most representative of
population exposures and a consideration of the practical factors
noted above.
* * * * *
7.3. Spacing from Roadways. This criteria applies only to those
Pb sites designed to assess lead concentrations from mobile sources.
Numerous studies have shown that ambient Pb levels near mobile
sources are a function of the traffic volume and are most pronounced
at ADT >30,000 within the first 15 meters on the downwind side of
the roadways.
* * * * *
7.4. Spacing from trees and other considerations. Trees can
provide surfaces for deposition or adsorption of Pb particles and
obstruct normal wind flow patterns. For microscale and middle scale
category (a) sites there must not be any tree(s) between the source
of the Pb and the sampler. For neighborhood scale category (b)
sites, the sampler should be at least 20 meters from the drip line
of trees. The sampler must, however, be placed at least 10 meters
from the drip line of trees which could be classified as an
obstruction, i.e., the distance between the tree(s) and the sampler
is less than the height that the tree protrudes above the sampler.
* * * * *
13. References
* * * * *
18. Air Quality Criteria for Lead. Office of Research and
Development, U.S. Environmental Protection Agency, Washington, DC
EPA-600/8-83-028 aF-dF, 1986, and supplements EPA-600/8-89/049F,
August 1990. (NTIS document numbers PB87-142378 and PB91-138420.)
* * * * *
7. Section 1 and section 2 b of Appendix G are revised to read as
follows:
Appendix G--Uniform Air Quality Index and Daily Reporting
* * * * *
1. General. This appendix describes the uniform air quality index
to be used by States in reporting the daily air quality index required
by Sec. 58.50.
[[Page 3037]]
2. Definitions.
* * * * *
b. Reporting Agency means the applicable State agency or a local
air pollution control agency designated by the State, that will carry
out the provisions of Sec. 58.50.
* * * * *
[FR Doc. 99-1125 Filed 1-19-99; 8:45 am]
BILLING CODE 6560-50-P
