6560-50-P 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 58 

[EPA–HQ–OAR–2006–0735; FRL– ] 

RIN 2060–A2060 

Revisions to Lead Ambient Monitoring Requirements 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Proposed rule; amendments. 

SUMMARY: The EPA issued a final rule on November 12, 2008,

(effective date January 12, 2009) that revised the National 

Ambient Air Quality Standard (NAAQS) for lead (Pb) and 

associated monitoring requirements. This action proposes 

revisions to the monitoring requirements in that final rule 

pertaining to where state and local monitoring agencies 

(“monitoring agencies”) would be required to conduct Pb 

monitoring. 

DATES: Comments must be received by [insert date 45 days after 

date of publication in the Federal Register]. 

ADDRESSES: Submit your comments, identified by Docket ID No. 

EPA-HQ-OAR-2006-0735 by one of the following methods: 

• http://www.regulations.gov: Follow the on-line 

instructions for submitting comments. 

• Email: a-and-r-Docket@epa.gov. 

• Fax: 202-566-9744. 
2 

• Mail: Docket No. EPA-HQ-OAR-2006-0735, Environmental 

Protection Agency, Mail Code 6102T, 1200 Pennsylvania Ave., 

NW., Washington, DC 20460. Please include a total of two 

copies. In addition, please mail a copy of your comments 

on the information collection provisions to the Office of 

Information and Regulatory Affairs, Office of Management 

and Budget (OMB), Attn: Desk Officer for EPA, 725 17

th St., 

NW, Washington, DC 20503. 

• Hand Delivery: Docket No. EPA-HQ-OAR-2006-0735, 

Environmental Protection Agency, EPA West, Room 3334, 1301 

Constitution Ave., NW, Washington, DC. Such deliveries are 

only accepted during the Docket’s normal hours of 

operation, and special arrangements should be made for 

deliveries of boxed information. 

Instructions: Direct your comments to Docket ID No. EPA-HQOAR-2006-0735. The EPA’s policy is that all comments received 

will be included in the public docket without change and may be 

made available online at www.regulations.gov, including any 

personal information provided, unless the comment includes 

information claimed to be Confidential Business Information 

(CBI) or other information whose disclosure is restricted by 

statute. Do not submit information that you consider to be CBI 

or otherwise protected through www.regulations.gov or email. 

The www.regulations.gov website is an “anonymous access” system, 
3 

which means EPA will not know your identity or contact 

information unless you provide it in the body of your comment. 

If you send an email comment directly to EPA without going 

through www.regulations.gov, your email address will be 

automatically captured and included as part of the comment that 

is placed in the public docket and made available on the 

Internet. If you submit an electronic comment, EPA recommends 

that you include your name and other contact information in the 

body of your comment and with any disk or CD-ROM you submit. If 

EPA cannot read your comment due to technical difficulties and 

cannot contact you for clarification, EPA may not be able to 

consider your comment. Electronic files should avoid the use of 

special characters, any form of encryption, and be free of any 

defects or viruses. For additional information about EPA’s 

public docket, visit the EPA Docket Center homepage at 

http://www.epa.gov/epahome/dockets.htm. 

Docket: All documents in the docket are listed in the 

www.regulations.gov index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other 

information whose disclosure is restricted by statute. Certain 

other material, such as copyrighted material, will be publicly 

available only in hard copy. Publicly available docket 

materials are available either electronically in 

www.regulations.gov or in hard copy at the Air and Radiation 
4 

Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 

Constitution Ave., NW, Washington, DC. The Public Reading Room 

is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, 

excluding legal holidays. The telephone number for the Public 

Reading Room is (202) 566-1744, and the telephone number for the 

Air and Radiation Docket and Information Center is (202) 566-

1742.

FOR FURTHER INFORMATION CONTACT: For further information 

contact Mr. Kevin Cavender, Air Quality Assessment Division, 

Office of Air Quality Planning and Standards, U.S. Environmental 

Protection Agency, Mail Code C304-06, Research Triangle Park, NC 

27711; telephone: 919-541-2364; fax: 919-541-1903; email: 

cavender.kevin@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. What Should I Consider as I Prepare My Comments for

 EPA?

1. Submitting CBI. Do not submit this information to EPA 

through www.regulations.gov or email. Clearly mark the part or 

all of the information that you claim to be CBI. For CBI 

information in a disk or CD-ROM that you mail to EPA, mark the 

outside of the disk or CD-ROM as CBI and then identify 

electronically within the disk or CD-ROM the specific 

information that is claimed as CBI. In addition to one complete 
5 

version of the comment that includes information claimed as CBI, 

a copy of the comment that does not contain the information 

claimed as CBI must be submitted for inclusion in the public 

docket. Information so marked will not be disclosed except in 

accordance with procedures set forth in 40 CFR part 2. 

 2. Tips for Preparing Your Comments. When submitting 

comments, remember to: 

• Identify the rulemaking by docket number and other 

identifying information (subject heading, Federal Register

date, and page number). 

• Follow directions – the agency may ask you to respond to 

specific questions or organize comments by referencing a 

Code of Federal Regulations (CFR) part or section number. 

• Explain why you agree or disagree, suggest alternatives, 

and substitute language for your requested changes.

• Describe any assumptions and provide any technical 

information and/or data that you used. 

• If you estimate potential costs or burdens, explain how you 

arrived at your estimate in sufficient detail to allow for 

it to be reproduced. 

• Provide specific examples to illustrate your concerns, and 

suggest alternatives. 
6 

• Explain your views as clearly as possible, avoiding the use 

of profanity or personal threats. 

• Make sure to submit your comments by the comment period 

deadline identified. 

B. Availability of Related Information

A number of documents relevant to this rulemaking, 

including the notice of final rulemaking (73 FR 66964), the 

notice of proposed rulemaking (73 FR 29184), the advance notice 

of proposed rulemaking (72 FR 71488), the Air Quality Criteria 

for Lead (Criteria Document) (USEPA, 2006), the Staff Paper, and 

other related technical documents are available on EPA’s Office 

of Air Quality Planning and Standards (OAQPS) Technology 

Transfer Network (TTN) web site at 

http://www.epa.gov/ttn/naaqs/standards/pb/s_pb_index.html. 

These and other related documents are also available for 

inspection and copying in the EPA docket identified above. 

C. When Would a Public Hearing Occur?

If anyone contacts EPA requesting to speak at a public 

hearing concerning this proposed rule by [insert date 10 days 

after publication in the Federal Register], we will hold a 

public hearing on [insert date 15 days after publication in the 

Federal Register]. If [insert date 15 days after publication in 

the Federal Register] falls on a Friday, Saturday, or Sunday, 

the hearing will be held on the following Monday. Persons 
7 

interested in presenting oral testimony at the hearing, or 

inquiring as to whether a hearing will be held, should contact 

Kevin A. Cavender at (919) 541– 2364 at least 2 days in advance 

of the hearing. If a public hearing is held, it will be held at 

10 a.m. at the EPA’s campus located at 109 T.W. Alexander Drive 

in Research Triangle Park, NC, or an alternate site nearby. 

Under CAA section 307(d)(1)(V), the Administrator determines 

that the provisions of section 307(d) are applicable to this 

proposal and all the procedural requirements of section 307(d) 

will apply to it. 

D. How is This Document Organized?

 The information presented in this document is organized as 

follows: 

I. General Information 

 A. What Should I Consider as I Prepare My Comments

for EPA? 

 B. Availability of Related Information 

 C. When Would a Public Hearing Occur? 

 D. How is This Document Organized? 

II. Background 

III. Source-Oriented Monitoring Requirements 

A. Background on Source-Oriented Monitoring 

Requirements 

B. Issues With Source-Oriented Monitoring 

Requirements 

C. Reconsideration of Source-Oriented Monitoring 

Requirements 

IV. Non-Source-Oriented Monitoring Requirements 

A. Background on Non-Source-Oriented Monitoring 

Requirements 

B. Issues With Non-Source-Oriented Monitoring 

Requirements 

C. Reconsideration of Non-Source-Oriented Monitoring 

Requirements 
8 

V. Increase in Lead Monitors and Timeline for Deploying 

New Monitors 

VI. Statutory and Executive Order Reviews 

 A. Executive Order 12866: Regulatory Planning and

Review 

 B. Paperwork Reduction Act 

 C. Regulatory Flexibility Act 

 D. Unfunded Mandates Reform Act 

 E. Executive Order 13132: Federalism 

 F. Executive Order 13175: Consultation and 

Coordination with Indian Tribal Governments 

 G. Executive Order 13045: Protection of Children 

From Environmental Health and Safety Risks 

 H. Executive Order 13211: Actions That Significantly 

Affect Energy Supply, Distribution or Use 

 I. National Technology Transfer and Advancement Act 

 J. Executive Order 12898: Federal Actions to 

Address Environmental Justice in Minority 

Populations and Low-Income Populations 

VII. References 

 

II. Background 

The EPA issued a final rule on November 12, 2008, that 

revised the NAAQS for Pb and associated ambient air Pb 

monitoring requirements (73 FR 66964, codified at 40 CFR part 

58). As part of the Pb monitoring requirements, monitoring 

agencies are required to monitor ambient air near Pb sources 

which are expected to or have been shown to have a potential to 

contribute to a 3-month average Pb concentration in ambient air 

in excess of the level of the NAAQS. At a minimum, monitoring 

agencies must monitor near Pb sources that emit 1.0 ton per year 

(tpy) or more. However, this requirement can be waived by the 

EPA Regional Administrator if the monitoring agency can 

demonstrate that the source will not contribute to a 3-month 
9 

average Pb concentration in ambient air in excess of 50 percent 

of the level of the NAAQS (based on historical monitoring data, 

modeling, or other means). 

Monitoring agencies are also currently required to conduct 

Pb monitoring in large urban areas (identified as Core Based 

Statistical Areas, or CBSAs, as defined by the OMB) with a 

population of 500,000 people or more. The locations for these 

monitoring sites are intended to measure neighborhood-scale Pb 

concentrations in urban areas impacted by resuspended dust from 

roadways, closed industrial sources which previously were 

significant sources of Pb, hazardous waste sites, construction 

and demolition projects, or other fugitive dust sources of Pb. 

Following promulgation of the revised Pb NAAQS and 

monitoring requirements, Natural Resources Defense Council, the 

Missouri Coalition for the Environment Foundation, Physicians 

for Social Responsibility, and Coalition to End Childhood Lead 

Poisoning (“the Petitioners”) petitioned (NRDC, 2009) for a 

reconsideration of the Pb emission rate at which monitoring is 

required (the “emission threshold,” currently 1.0 tpy). On July 

22, 2009, the EPA granted the petition to reconsider aspects of 

the monitoring requirements (Jackson, 2009). In response to the 

petition, the EPA reviewed and reconsidered the monitoring 

requirements and is proposing revisions to the requirements for 

both source-oriented and non-source-oriented monitoring for Pb. 
10 

III. Source-Oriented Monitoring Requirements 

The EPA is proposing to change the Pb emission threshold at 

which monitoring agencies are presumptively required to conduct 

Pb monitoring near a Pb source to 0.50 tpy from an emissions 

threshold of 1.0 tpy. The EPA is also seeking comments on 

alternative emission thresholds between 0.50 tpy to 1.0 tpy. 

The following paragraphs discuss the issues considered, the 

proposed changes, and our rationale for the proposed changes to 

the source-oriented monitoring requirements. 

A. Background on Source-Oriented Monitoring Requirements

 In the final revisions to the Pb NAAQS, the EPA noted that 

due to the dramatic drop in Pb concentrations since the phase 

out of Pb in motor vehicle gasoline, the EPA expected 

concentrations of Pb to approach the revised level of the Pb 

NAAQS primarily near sources of Pb. Accordingly, the EPA 

required monitoring near Pb emission sources such as Pb 

smelters, metallurgical operations, battery manufacturing, and 

other source categories that emit Pb. 

The EPA also noted in the final NAAQS rulemaking that it is 

not practical to conduct monitoring at every Pb emission source, 

nor is it likely that very small Pb emission sources will cause 

ambient concentrations to exceed the promulgated NAAQS. 

Therefore, the EPA performed an analysis to determine at what 

level of Pb emissions (the “emissions threshold”) it may be 
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possible for an emission source to cause ambient Pb

concentrations to exceed the Pb NAAQS (Cavender, 2008). This 

analysis looked at a range of levels and indicated that, under 

reasonable worst-case conditions, a 0.50 tpy Pb source could 

cause ambient Pb concentrations to exceed the revised Pb NAAQS. 

The EPA also noted that by basing the monitoring requirements on 

worst-case conditions, the EPA would be “placing an unnecessary 

burden on monitoring agencies to evaluate or monitor around 

sources that may not have a significant potential to exceed the 

NAAQS.” As such, the EPA required monitoring agencies to take 

into account Pb sources which are expected to or have been shown 

to contribute to a maximum Pb concentration in ambient air in 

excess of the NAAQS including, at a minimum, to conduct Pb 

monitoring [or request monitoring waivers as allowed for under 

40 CFR part 58, Appendix D, paragraph 4.5(a)(ii)] near Pb 

sources emitting 1.0 or more tpy. To account for Pb sources 

emitting less than 1.0 tpy of Pb that may have the potential to 

cause Pb concentrations to exceed the Pb NAAQS, the final rule 

provided the EPA Regional Administrators the authority to 

require additional monitoring beyond the minimum monitoring 

requirements where the likelihood of Pb air quality violations 

is significant or where the emissions density, topography, or 

population locations are complex and varied. The EPA projected 

the source-oriented portion of the network to be up to 135 
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monitors based on these requirements and on information 

available at the time the final rule was published (i.e., the 

2002 NEI)1. 

B. Issues With Source-Oriented Monitoring Requirements

The Petitioners cited several reasons for EPA to reconsider 

the Pb monitoring emission threshold (NRDC, 2009). They noted 

that the finalized emission threshold of 1.0 tpy was above the 

proposed range of 200 to 600 kilograms per year and, therefore, 

argued that the EPA failed to provide for proper public comment 

on the 1.0 tpy threshold. They also argued that the selection 

of the 1.0 tpy emission threshold was arbitrary and capricious 

and that the EPA did not follow its own analysis. Finally, they 

argued that the 1.0 tpy emission threshold would not provide for 

an adequate margin of safety as required by the Clean Air Act. 

The EPA granted the petition to reconsider the monitoring 

emission threshold (Jackson, 2009), and this proposed rule 

reflects our reconsideration of the emission threshold. 

In addition to the petition to reconsider, the EPA has 

received informal feedback from members of the National 

Association of Clean Air Agencies (NACAA) monitoring 

subcommittee regarding monitoring of airports from which Pb is 

emitted as a result of the use of leaded aviation fuel 

 

1 Note that the 2005 NEI is now available and the EPA has used the Pb emission 

estimates in the 2005 NEI for estimating the impact of these proposed 

revisions. Based on the 2005 NEI, 111 source-oriented monitoring sites would 

be required under the existing monitoring requirements. 
13 

(Cavender, 2009). These NACAA members believe that the final Pb 

NAAQS rulemaking inappropriately treats airports in the same 

manner as industrial Pb sources and claim that Pb emissions at 

airports will have a lesser impact on ambient Pb concentrations 

since the Pb emissions from airplanes taking off from or landing 

at airports are spread out over a larger area, unlike industrial 

sources where the emissions may be emitted from a few stacks. 

C. Reconsideration of Source-Oriented Monitoring Requirements

 The monitoring emission threshold was intended to identify 

Pb sources which may have the potential to contribute to or 

approach an exceedance of the Pb NAAQS and near which Pb 

monitoring should be conducted (or where a site-specific 

evaluation of the potential for the Pb source to contribute to 

an exceedance of the Pb NAAQS should be performed). The EPA’s 

analysis to determine the emission threshold relied on three 

different approaches. 

One of the three approaches relied on the use of existing 

Pb monitoring data near Pb sources. The EPA believes this 

approach provides the best information on the potential impact 

of Pb sources on ambient Pb concentrations because it uses 

actual source-oriented Pb monitoring data from near actual Pb 

sources. As such, this approach was reviewed as part of the 

EPA’s reconsideration. Under this approach, source-oriented Pb 

monitors within 1 mile of a Pb source (identified from the 2002 
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National Emissions Inventory (NEI)) were identified. This group 

of sites was then narrowed down to sites near facilities 

emitting 1 tpy or more of Pb into the ambient air, and then to 

sites which were only impacted by one Pb emitting facility. 

Also, in cases where more than one monitor was identified within 

1 mile of the same facility emitting 1 tpy or more of Pb 

annually, the EPA only used the monitor measuring the maximum Pb 

concentration in the analysis. In this manner, the EPA 

identified seven monitor-facility pairs meeting the emissions 

and distance criteria. Using data in the Air Quality System 

(AQS) database (http://www.epa.gov/ttn/airs/airsaqs/) for the 

years 2003-2005, the EPA developed an estimate of the maximum 3-

month average Pb concentration for each monitoring site. Next, 

EPA calculated a ratio of the maximum 3-month average 

concentration to the facility annual emissions (as identified in 

the 2002 NEI) to provide an estimate of the impact from the 

facility in units of μg/m3 per tpy. Dividing the level of the Pb 

NAAQS (0.15 μg/m3) by this ratio provides an estimate of the 

annual emission level for the facility which would result in 

ambient Pb concentrations just meeting the Pb NAAQS, referred to 

here as a “site-specific emission threshold” (see Table 1). 

Table 1. Data Used to Estimate Facility Impacts Based on 

Monitoring Data 

Maximum 3-

Month Average 

NEI 2002 

Facility 

SiteSpecific 
15 

AQS Site 

Id 

Pb 

Concentration 

(μg/m3) 

Emission 

Rate 

(tpy) 

Ratio 

(μg/m3-

tpy) 

Emission 

Threshold 

(tpy) 

171190010 0.33 1.3 0.3 0.5 

340231003 0.18 1.7 0.1 1.5 

471870100 0.89 2.6 0.3 0.5 

480850009 0.75 3.2 0.2 0.8 

420110717 0.40 4.8 0.1 1.5 

011090003 1.20 4.5 0.3 0.5 

290990013 1.29 58.8 0.02 7.5 

This analysis shows that four of these seven Pb sources 

support an emission threshold less than the emission threshold 

of 1.0 tpy set by the final rule on the revised Pb NAAQS. In 

the final rule, however, the EPA stated that an emission 

threshold of 1.0 tpy “is more likely to clearly identify sources 

that would contribute to exceedances of the NAAQS” as compared 

to a lower emission threshold. Upon further consideration and 

based on the information provided in Table 1, the EPA no longer 

supports an emission threshold of 1.0 tpy. Based on this sample 

of Pb sources, it appears that many Pb sources that emit between 

0.50 and 1.0 tpy may have the potential to cause ambient Pb 

concentrations to exceed or approach the Pb NAAQS. A 1.0 tpy 

emission threshold would not identify these sources. This could 

result in a large number of areas with a potential to have Pb 

concentrations above the Pb NAAQS not being properly monitored 

and could result in some areas where the NAAQS is exceeded not 

being identified as nonattainment for Pb. This result would be 

contrary to the purpose of the NAAQS to protect public health 
16 

with an adequate margin of safety and also to protect public 

welfare. As such, the EPA has reconsidered the emission 

threshold and proposes to lower the emission threshold to a 

level of 0.50 tpy, consistent with the analysis performed for 

the final rule (Cavender, 2008). The EPA believes an emission 

threshold of 0.50 tpy would protect public health with an 

adequate margin of safety. The EPA is also seeking comments on 

setting an emission threshold between 0.50 tpy and 1.0 tpy, 

i.e., require monitoring near sources that emit Pb at some level 

between 0.50 tpy and 1.0 tpy. 

 As discussed above, the EPA has received comments from the 

NACAA monitoring subcommittee claiming that airports should not 

be treated in the same manner as industrial sources of Pb with 

regards to monitoring requirements (Cavender, 2009). This 

perspective is based on the belief that Pb emissions at airports 

will have a lesser impact on off-airport and on-airport ambient 

Pb concentrations because the Pb emissions from airplanes taking 

off from or landing at airports are spread out over a larger 

area resulting in greater dilution of ambient concentrations, 

unlike industrial sources where the bulk of emissions may be 

emitted from a few stacks resulting in relatively higher 

concentrations. 

The EPA has limited quantitative information with which to 

evaluate the impact on either on-airport or off-airport ambient 
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Pb concentrations from airports. One study conducted near the 

Santa Monica airport measured a maximum 3-month average Pb 

concentration of 0.1 μg/m3 near the runway blast fence (Fine, 

2007). Based on the 2002 Pb emission estimate for the Santa 

Monica airport of 0.4 tpy (USEPA, 2008a), an estimated sitespecific emission threshold of 0.6 tpy can be calculated using 

the same procedures used to estimate a site-specific emission 

threshold as above [i.e., 0.15 μg/m3 /(0.1 μg/m3 / 0.4 tpy) = 0.6 

tpy]. This site-specific emission threshold (0.6 tpy) falls 

within the lower end of the range of specific emission 

thresholds calculated for industrial sources above (0.50 to 7.5 

tpy), and does not support the case for different treatment of 

airports. The EPA is not aware of similar studies where lead 

was monitored at or near the maximum impact area on airport 

property and does not believe there are sufficient data to 

develop or justify a separate emission threshold for airports. 

As such, the EPA proposes to treat airports identically to other 

sources of Pb, and require monitoring agencies to conduct Pb 

monitoring (or request a monitoring waiver) at or near airports 

that emit 0.50 tpy of Pb, as is required for other sources of 

Pb. The EPA solicits comments on this issue, on the 

availability of other data that may be useful in setting an 

alternative emission threshold for airports, and whether EPA 

should consider other factors or criteria that might be useful 
18 

in determining if a different emission threshold is appropriate 

for airports. 

In addition, the EPA is proposing to edit the wording of 

the source-oriented monitoring requirement [40 CFR part 58, 

Appendix D, paragraph 4.5(a)] for clarity. The EPA believes the 

edits are merely editorial and are consistent with the purpose 

and intent of the existing requirement. 

IV. Non-Source-Oriented Monitoring Requirements 

 The EPA is proposing to replace the current non-sourceoriented monitoring approach with the requirement for Pb 

monitoring at the national multi-pollutant monitoring network 

known as NCore. The following paragraphs discuss the issues 

considered, the proposed changes, and our rationale for the 

proposed changes to the non-source-oriented monitoring 

requirements. 

A. Background on Non-Source-Oriented Monitoring

 Requirements

 As part of the November 2008 revisions to the Pb NAAQS, the 

EPA required one Pb monitor site in each Core Based Statistical 

Areas (CBSA) with a population of 500,000 people or more - 

leading to 101 monitors. These monitors are to be located to 

measure neighborhood scale Pb concentrations in urban areas 

impacted by re-suspended dust from roadways, closed industrial 

sources which previously were significant sources of Pb, 
19 

hazardous waste sites, construction and demolition projects, or 

other fugitive dust sources of Pb. 

The EPA had proposed (73 FR 29184) and taken comments on a 

smaller non-source-oriented Pb monitoring network, that included 

1 monitor in each CBSA with a population of 1,000,000 or more 

people, located to measure typical neighborhood scale Pb 

concentrations in urban areas – which would have required 50 

monitors. The EPA noted that data from these non-sourceoriented monitors would be helpful in better characterizing 

population exposure to ambient air related Pb and may assist in 

determining nonattainment boundaries. 

Concerns were raised during review of the draft final 

notice that non-inventoried Pb sources in urban areas such as 

closed industrial sources, hazardous waste sites, and 

construction and demolition projects could potentially result in 

ambient Pb concentrations in excess of the Pb NAAQS. To address 

these concerns, the EPA modified the siting criteria to require 

non-source-oriented monitors to be sited to evaluate these noninventoried Pb sources. The EPA also lowered the population 

threshold from requiring monitoring at CBSAs with a population 

of 1,000,000 people or more to requiring monitoring at CBSAs 

with a population of 500,000 people or more. 

B. Issues With Non-Source-Oriented Monitoring Requirements
20 

 Some sources of Pb which are not in the current NEI that 

could result in ambient Pb concentrations in excess of the Pb 

NAAQS have been identified (USEPA, 2008b). However, as 

currently written, it is not clear that the non-source-oriented 

monitoring requirements would result in monitors near such noninventoried sources. The non-source-oriented monitors are to be 

sited as neighborhood scale monitors. Yet, Pb concentrations 

drop off rapidly with distance away from a source, such that it 

is unlikely that non-source-oriented monitors would identify the 

maximum Pb concentration near non-inventoried sources where the 

Pb NAAQS could be exceeded. Furthermore, locations near noninventoried sources outside of CBSAs with a population of 

500,000 people or more would not be addressed by the current 

non-source-oriented requirements and, as such, these sources 

would not necessarily be monitored. The final siting 

requirements also would not support the measurement of trends in 

typical urban Pb concentrations, one of EPA’s original 

objectives. 

C. Reconsideration of Non-Source-Oriented Monitoring

 Requirements

 After further consideration, the EPA believes the most 

appropriate approach to achieve the placement of monitors near 

non-inventoried sources that have the potential to cause an 

exceedance of the NAAQS is through the existing source-oriented 
21 

monitoring network requirements (paragraph 4.5(a) of Appendix D 

to 40 CFR part 58) which require monitoring agencies to conduct 

Pb monitoring at sources “which are expected to or have been 

shown to contribute to a maximum Pb concentration in ambient air 

in excess of the NAAQS” and the EPA Regional Administrators’ 

authority to require monitoring “where the likelihood of Pb air 

quality violations is significant.” These non-inventoried Pb 

sources may be identified by monitoring agencies, the EPA, or 

concerned citizens as part of the network plan review and 

approval requirements. Furthermore, monitors sited under the 

source-oriented monitoring requirements are required to be sited 

at the location of estimated maximum concentration and, as such, 

better serve the purpose of identifying violations of the Pb 

NAAQS. 

The EPA believes it is appropriate to re-emphasize the 

objectives identified in the proposed rule for non-sourceoriented monitors, i.e., measuring typical neighborhood-scale Pb 

concentrations in urban areas so we can better understand the 

risk posed by Pb to the general population, and to provide 

information that could assist with the determination of 

nonattainment boundaries. In addition, the EPA believes nonsource-oriented sites are important to support the development 

of long-term trends at typical concentrations sites. 
22 

The EPA notes that these objectives match those of the 

multi-pollutant NCore network required under section 3 of 

Appendix D to 40 CFR part 58 and also believes that EPA’s 

increasing support for multi-pollutant measurements should be 

considered in the design of the Pb network. The NCore network 

is intended to be a long-term, multi-pollutant, monitoring 

network that not only provides information useful to NAAQS 

attainment decisions, but also to provide data needed to broaden 

the understanding of air quality conditions and pollutant 

interactions, evaluate air quality models, develop emission 

control strategies, and support long-term health studies. We 

also note that Pb monitoring is already required in at least one 

NCore site per EPA Region. As such, one option for implementing 

Pb non-source-oriented monitoring is to require Pb monitoring at 

all NCore sites rather than the population-based approach 

currently used. This option provides a similar result to that 

of basing the non-source-oriented monitoring requirements on 

population (as was established in the November 2008 final rule), 

and has additional similarities with the provisions adopted in 

the final rule on the revised Pb NAAQS including: 

o The size of the network would be approximately the same as 

the original proposal, but would span a wider range of 

populations. The NCore network will consist of 

approximately 80 sites, with approximately 50 of these 
23 

being in urban areas with a population of 500,000 people or 

more. 

o NCore sites will be neighborhood-scale sites., and 

o NCore sites are long-term trends sites suitable for longterm population exposure studies. 

In addition, many NCore sites will have the low-volume PM10

sampler necessary to conduct Pb monitoring, reducing the cost 

and time necessary to implement the non-source-oriented 

monitoring requirements.2 Additional information on the 

objectives and specific sites for NCore can be obtained online 

at http://www.epa.gov/ttn/amtic/ncore/index.html. Due to the 

many advantages of including Pb monitoring at NCore sites rather 

than having separate non-source-oriented monitoring

requirements, the EPA is proposing to revise the existing nonsource-oriented monitoring requirements (paragraph 4.5(b) of 

Appendix D to 40 CFR part 58) to require Pb monitoring at NCore 

sites in place of the current CBSA population-based

requirements. The EPA seeks comments on the use of the NCore 

network to meet the non-source-oriented monitoring objectives 

 

2 EPA expects that low-volume PM10 samplers will be used at many NCore sites in 

order to meet the existing requirement for PM10-2.5 measurements. However, EPA 

notes that some NCore sites may use a dichotomous sampler or a continuous PM10-

2.5 sampler that would not be compatible with Pb-PM10 sampling such that these 

sites would need to add an additional low-volume PM10 sampler to perform PbPM10 sampling. In addition, if Pb-PM10 concentrations are found to be greater 

than 0.10 μg/m3, a Pb-TSP sampler would be required at the NCore site 

according to paragraph 2.10.1.1 of Appendix C to 40 CFR part 58, within 6 

months. 
24 

for Pb. The EPA also seeks comments on if Pb monitoring should 

be required at all NCore sites, or only urban NCore sites. 

V. Increase in Lead Monitors and Timeline for Deploying New 

Monitors 

These proposed revisions to the monitoring requirements 

will result in an increase in the number of Pb monitors that 

monitoring agencies must deploy and operate relative to the 

estimated number of monitors for the November 2008 final rule. 

Based on the 2005 NEI and the 2002 estimates for Pb emissions 

from airports (EPA, 2008a), the current monitoring requirements 

would require up to 212 Pb monitors - 111 source-oriented 

monitors3 (106 industrial and 5 airport) and 101 non-sourceoriented monitors. Based on the monitoring requirements 

proposed here, the number of total required monitors increases 

to 352 monitors with 272 source-oriented monitors (217 

industrial and 55 airport) and 80 non-source-oriented monitors. 

However, we expect that the number of actual Pb monitors will 

likely be less than 352 since these values do not take into 

account the probability that monitoring agencies will request 

and attain waivers from source-oriented monitoring requirements 

for some of the Pb sources identified as emitting more than 0.50 

tpy of Pb. 

 

3 Note that the current estimate of the required source-oriented sites is 

lower than the estimate identified in the final rule (135 sites) because the 

current estimate is based on the 2005 NEI rather than the 2002 NEI. 
25 

 This proposal still requires monitoring agencies to have Pb 

monitors installed and operating near sources emitting 1.0 tpy 

of Pb or more by January 1, 2010 (i.e., the deadline specified 

in the November 2008 final rule). The EPA proposes that if we 

revise the monitoring requirements, monitoring agencies would 

have 6 months from the effective date of the final rule to 

update their annual monitoring network plans. The update would 

incorporate plans for source-oriented monitors near Pb sources 

emitting 0.50 tpy or more, but less than 1.0 tpy. The EPA is 

also proposing to allow 1 year from the date of the final rule 

for monitoring agencies to install and begin operation of 

source-oriented monitors near Pb sources emitting 0.50 tpy or 

more, but less than 1.0 tpy. The EPA notes that this timeline 

would require monitoring agencies to evaluate, site, and install 

up to 161 source-oriented monitoring sites within 1 year of 

promulgation of the revised monitoring requirements. While the 

EPA believes this is feasible, the EPA seeks comments on the 

appropriateness of allowing deployment in phases requiring half 

of the sites for sources between 0.50 and 1.0 tpy to be 

installed during the first year following promulgation of the 

final monitoring requirements, and for the remaining half to be 

installed during the second year following promulgation of the 

final monitoring requirements. The EPA also solicits comments 

on what factors, such as source category, should be considered 
26 

when prioritizing which sites should be installed during the 

first year versus the second. 

 Monitoring agencies must have installed and begun operation 

of required NCore sites and monitors (other than Pb) by January 

1, 2011. Because the necessary siting and site installation 

will already be in place at NCore sites, the EPA does not 

believe any additional time beyond that of the existing NCore 

schedule is required for monitoring agencies to install any 

necessary Pb monitors and begin Pb sampling at NCore sites. As 

such, the EPA is proposing to require monitoring agencies to 

commence Pb sampling at NCore sites when NCore sites are to be 

implemented, no later than January 1, 2011. 

The EPA recognizes that these proposed requirements will 

likely not be finalized until spring 2010 which is just a few 

months before monitoring agencies are currently required to 

submit their Pb network plans for non-source-oriented monitors 

(July 1, 2010). Because this reconsideration may affect where 

non-source-oriented monitors may be required, the EPA is 

advising monitoring agencies not site or install non-sourceoriented monitors until after this reconsideration is complete 

and the final revisions are promulgated. 

VI. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory Planning and Review
27 

Under Executive Order 12866 (58 FR 51735, October 4, 1993), 

this action is a "significant regulatory action” because it was 

deemed to “raise novel legal or policy issues.” Accordingly, 

EPA submitted this action to the Office of Management and Budget 

(OMB) for review under Executive Order 12866 and any changes 

made in response to OMB recommendations have been documented in 

the docket for this action. 

B. Paperwork Reduction Act

The information collection requirements in this proposed 

rule have been submitted for approval to OMB under the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. The Information 

Collection Request (ICR) document prepared by EPA has been 

assigned EPA ICR number 0940.23. 

The monitoring, recordkeeping, and reporting requirements 

in 40 CFR parts 58 are specifically authorized by sections 100, 

301(a), and 319 of the Clean Air Act. All information submitted 

to EPA pursuant to the monitoring, recordkeeping, and reporting 

requirements for which a claim of confidentiality is made is 

safeguarded according to Agency policies in 40 CFR part 2, 

subpart B. 

 The information collected and reported under 40 CFR part 58 

is needed to determine compliance with the NAAQS, to 

characterize air quality and associated health and ecosystem 

impacts, to develop emissions control strategies, and to measure 
28 

progress for the air pollution program. The proposed amendments 

would revise the technical requirements for Pb monitoring sites, 

require the siting and operation of additional Pb ambient air 

monitors, and require the reporting of the collected ambient Pb 

monitoring data to EPA’s AQS. The annual average reporting 

burden for the collection under 40 CFR part 58 (averaged over 

the first 3 years of this ICR) for 140 respondents is estimated

to increase by a total of 19,551 labor hours per year with an 

increase of $1,849,264 per year. Burden is defined at 5 CFR 

1320.3(b). State, local, and Tribal entities are eligible for 

state assistance grants provided by the federal government under 

the CAA which can be used for monitors and related activities. 

An agency may not conduct or sponsor, and a person is not 

required to respond to, a collection of information unless it 

displays a currently valid OMB control number. The OMB control 

numbers for EPA's regulations in 40 CFR are listed in 40 CFR 

part 9. 

 To comment on the Agency's need for this information, the 

accuracy of the provided burden estimates, and any suggested 

methods for minimizing respondent burden, EPA has established a 

public docket for this rule, which includes this ICR, under 

Docket ID number EPA-HQ-OAR-2006-0735. Submit any comments 

related to the ICR to EPA and OMB. See ADDRESSES section at the 

beginning of this notice for where to submit comments to EPA. 
29 

Send comments to OMB at the Office of Information and Regulatory 

Affairs, Office of Management and Budget, 725 17th Street, NW, 

Washington, DC 20503, Attention: Desk Office for EPA. Since OMB 

is required to make a decision concerning the ICR between 30 and 

60 days after [Insert date of publication in the Federal

Register], a comment to OMB is best assured of having its full 

effect if OMB receives it by [Insert date 30 days after 

publication in the Federal Register.]. The final rule will 

respond to any OMB or public comments on the information 

collection requirements contained in this proposal. 

C. Regulatory Flexibility Act

 The Regulatory Flexibility Act (RFA) generally requires an 

agency to prepare a regulatory flexibility analysis of any rule 

subject to notice and comment rulemaking requirements under the 

Administrative Procedure Act or any other statute 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 organizations, 

and small governmental jurisdictions. 

 For purposes of assessing the impacts of this rule on small 

entities, small entity is defined as: (1) a small business as 

defined by the Small Business Administration’s (SBA) regulations 

at 13 CFR 121.201; (2) a small governmental jurisdiction that 

is a government of a city, county, town, school district or 
30 

special district with a population of less than 50,000; and (3) 

a small organization that is any not-for-profit enterprise which 

is independently owned and operated and is not dominant in its 

field. 

 After considering the economic impacts of this proposed 

rule on small entities, I certify that this action will not have 

a significant economic impact on a substantial number of small 

entities. This proposed rule will not impose any requirements 

on small entities. Rather, this rule establishes monitoring 

requirements for state and local (where applicable) monitoring 

agencies. The EPA continues to be interested in the potential 

impacts of the proposed rule on small entities and welcomes 

comments on issues related to such impacts. 

D. Unfunded Mandates Reform Act

 This rule does not contain a federal mandate that may 

result in expenditures of $100 million or more for state, local, 

and Tribal governments, in the aggregate, or the private sector 

in any 1 year. The proposed amendments to 40 CFR part 58 are 

estimated to increase the ambient air monitoring costs by $1.8 

million and 19,551 labor hours from present levels. Thus, this 

rule is not subject to the requirements of sections 202 or 205 

of UMRA. 

This rule is also not subject to the requirements of 

section 203 of UMRA because it contains no regulatory 
31 

requirements that might significantly or uniquely affect small 

governments. Small governments that may be affected by the 

proposed amendments are already meeting similar requirements 

under the existing rules, and the costs of changing the network 

design requirements would be borne, in part, by the federal 

government through state assistance grants.

E. Executive Order 13132: Federalism

 Executive Order 13132, entitled “Federalism” (64 FR 43255, 

August 10, 1999), requires EPA to develop an accountable process 

to ensure “meaningful and timely input by state and local 

officials in the development of regulatory policies that have 

federalism implications.” “Policies that have federalism 

implications” are defined in the Executive Order to include 

regulations that have “substantial direct effects on the states, 

on the relationship between the national government and the 

states, or on the distribution of power and responsibilities 

among the various levels of government.” 

 This proposed rule does not have federalism implications. 

It will not have substantial direct effects on the states, on 

the relationship between the national government and the states, 

or on the distribution of power and responsibilities among the 

various levels of government, as specified in Executive Order 

13132. The rule does not alter the relationship between the 

Federal government and the states regarding the establishment 
32 

and implementation of air quality improvement programs as 

codified in the CAA. Under section 109 of the CAA, EPA is 

mandated to establish NAAQS; however, CAA section 116 preserves 

the rights of states to establish more stringent requirements if 

deemed necessary by a state. Furthermore, this rule does not 

impact CAA section 107 which establishes that the states have 

primary responsibility for implementation of the NAAQS. 

Finally, as noted in section D (above) on UMRA, this rule does 

not impose significant costs on state, local, or Tribal 

governments or the private sector. Thus, Executive Order 13132 

does not apply to this rule. 

However, EPA recognizes that states will have a substantial 

interest in this rule and any corresponding revisions to 

associated air quality surveillance requirements, 40 CFR part 

58. Therefore, in the spirit of Executive Order 13132, and 

consistent with EPA policy to promote communications between EPA 

and state and local governments, EPA specifically solicits 

comment on this proposed rule from state and local officials. 

F. Executive Order 13175: Consultation and Coordination

With Indian Tribal Governments

 This action does not have Tribal implications, as specified 

in Executive Order 13175 (65 FR 67249, November 9, 2000). It 

does not have a substantial direct effect on one or more Indian 

Tribes, since Tribes are not obligated to adopt or implement any 
33 

NAAQS. Thus, Executive Order 13175 does not apply to this 

action. EPA specifically solicits additional comment on this 

proposed action from Tribal officials. 

G. Executive Order 13045: Protection of Children From 

Environmental Health & Safety Risks

 The EPA interprets Executive Order 13045 (62 FR 19885, 

April 23, 1997) as applying only to those regulatory actions 

that concern health or safety risks, such that the analysis 

required under section 5-501 of the Executive Order has the 

potential to influence the regulation. This action is not 

subject to Executive Order 13045 because it does not establish 

an environmental standard intended to mitigate health or safety 

risks. 

H. Executive Order 13211: Actions That Significantly Affect 

Energy Supply, Distribution, or Use

 This action is not a “significant energy action” as defined 

in Executive Order 13211 (66 FR 28355 (May 22, 2001)), because 

it is not likely to have a significant adverse effect on the 

supply, distribution, or use of energy. This proposed rule 

would result in an insignificant increase in power consumption 

associated with the additional power required to run 140 

additional monitors nationwide. 

I. National Technology Transfer and Advancement Act
34 

 Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (“NTTAA”), Public Law 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. NTTAA directs EPA to provide 

Congress, through OMB, explanations when the Agency decides not 

to use available and applicable voluntary consensus standards. 

 This proposed rulemaking does not involve technical 

standards. Therefore, EPA is not considering the use of any 

voluntary consensus standards.

J. Executive Order 12898: Federal Actions to Address

Environmental Justice in Minority Populations and

Low-Income Populations

 Executive Order 12898 (59 FR 7629 (Feb. 16, 1994))

establishes federal executive policy on environmental justice. 

Its main provision directs federal agencies, to the greatest 

extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and 
35 

activities on minority populations and low-income populations in 

the United States. 

 The EPA has determined that this proposed rule will not 

have disproportionately high and adverse human health or 

environmental effects on minority or low-income populations 

because it increases the level of environmental protection for 

all affected populations without having any disproportionately 

high and adverse human health or environmental effects on any 

population, including any minority or low-income population. 

VII. References 

Cavender, K. (2008). Development of Final Source-oriented 

Monitoring Emission Threshold. Memorandum to the Lead 

NAAQS Review Docket. EPA-HQ-OAR-2006-0735. Available 

online at: 

http://www.epa.gov/ttnnaaqs/standards/pb/data/20081015Caven

der.pdf 

Cavender, K. (2009). Summary of Discussion of Pb Monitoring 

Near Airports at Spring 2009 NACAA Monitoring Subcommittee 

Meeting. Memorandum to the Lead NAAQS Review Docket. EPAHQ-OAR-2006-0735. 

Fine, Philip (2007). Community-Scale Air Toxics Monitoring - 

Sun Valley Neighborhood and General Aviation Airports. 

Presented at the U.S. EPA Air Toxics Data Analysis Workshop 
36 

- Chicago, IL, October 2 - 4, 2007. EPA-HQ-OAR-2006-0735. 

Available online at: 

http://www.epa.gov/ttn/amtic/files/ambient/airtox/2007-

workshop/07_100307_fine.pdf 

Jackson, L. (2009). Letter to petitioners. EPA-HQ-OAR-2006-

0735. Available online at: 

http://www.epa.gov/air/lead/pdfs/OAR.09.000.7687.pdf 

NRDC, et al. (2009). Petition to Reconsider. EPA-HQ-OAR-2006-

0735. Available online at: 

http://www.epa.gov/air/lead/pdfs/0122009petitionReconsidera

tion.pdf 

U.S. Environmental Protection Agency. (2006) Air Quality 

Criteria for Lead (Second External Review Draft). 

Washington, DC, EPA/600/R–05/144aB– bB. Available online 

at: 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=158823 

U.S. Environmental Protection Agency. (2008a) Lead Emissions 

from the Use of Leaded Aviation Gasoline in the United 

States. EPA420-R-08-020. Available online at: 

http://www.epa.gov/ttn/chief/net/tsd_avgas_pb_inventory_200

2.pdf
37 

U.S. Environmental Protection Agency. (2008b) Regulatory Impact 

Analysis of the Proposed Revisions to the National Ambient 

Air Quality Standards for Lead. EPA-HQ-OAR-2006-0735. 
Page 37 of 41 

Revisions to Lead Ambient Monitoring Requirements 

List of Subjects in 40 CFR Part 58 

Air pollution control, Environmental protection, 

Intergovernmental relations, Reporting and Recordkeeping 

Requirements. 

 ____________________ 

 Dated: 

____________________ 

Lisa P. Jackson, 

 Administrator. 
38 

For the reasons stated in the preamble, title 40, chapter I, 

part 58 of the Code of Federal Regulations is proposed to be 

amended as follows: 

PART 58—[AMENDED] 

1. The authority citation for part 58 continues to read as 

follows: 

Authority: 42 U.S.C. 7403, 7410, 7601(a), 7611, and 7619. 

Subpart B—[Amended] 

2. Section 58.10, is amended by revising paragraph (a)(4) to 

read as follows: 

§ 58.10 Annual monitoring network plan and periodic network 

assessment. 

 (a) * * * 

 (4) A plan for establishing source-oriented Pb monitoring 

sites in accordance with the requirements of appendix D to this 

part for Pb sources emitting 1.0 tpy or greater shall be 

submitted to the EPA Regional Administrator no later than July 

1, 2009, as part of the annual network plan required in 

paragraph (a)(1) of this section. The plan shall provide for 

the required source-oriented Pb monitoring sites for Pb sources 

emitting 1.0 tpy or greater to be operational by January 1, 

2010. A plan for establishing source-oriented Pb monitoring 

sites in accordance with the requirements of appendix D to this 

part for Pb sources emitting greater than 0.50 tpy but less than 
39 

1.0 tpy shall be submitted to the EPA Regional Administrator no 

later than [date 6 months after date of publication of the final 

rule in the Federal Register]. The plan shall provide for the 

required source-oriented Pb monitoring sites for Pb sources 

emitting greater than 0.50 tpy but less than 1.0 tpy to be 

operational by [date 12 months after date of publication of the 

final rule in the Federal Register]. 

* * * * * 

3. Appendix D to Part 58 is amended by revising paragraph 

3.(b), paragraph 4.5.(a), and paragraph 4.5.(b) to read as 

follows: 

Appendix D to Part 58—Network Design Criteria for Ambient Air 

Quality Monitoring 

 * * * * * 

 3. * * * 

 (b) The NCore sites must measure, at a minimum, PM2.5

particle mass using continuous and integrated/filter-based 

samplers, speciated PM2.5, PM10–2.5 particle mass, speciated PM10–

2.5, O3, SO2, CO, NO/NOy, Pb, wind speed, wind direction, relative 

humidity, and ambient temperature. 

 * * * * * 

 4.5 Lead (Pb) Design Criteria. (a) state and, where 

appropriate, local agencies are required to conduct ambient air 
40 

Pb monitoring near Pb sources which are expected to or have been 

shown to contribute to a maximum Pb concentration in ambient air 

in excess of the NAAQS, taking into account the logistics and 

potential for population exposure. At a minimum, there must be 

one source-oriented SLAMS site located to measure the maximum Pb 

concentration in ambient air resulting from each Pb source which 

emits 0.50 or more tons per year based on either the most recent 

National Emission Inventory 

(http://www.epa.gov/ttn/chief/eiinformation.html) or other 

scientifically justifiable methods and data (such as improved 

emissions factors or site-specific data) taking into account 

logistics and the potential for population exposure. 

 (i) One monitor may be used to meet the requirement in 

paragraph 4.5(a) for all sources involved when the location of 

the maximum Pb concentration due to one Pb source is expected to 

also be impacted by Pb emissions from a nearby source (or 

multiple sources). This monitor must be sited, taking into 

account logistics and the potential for population exposure, 

where the Pb concentration from all sources combined is expected 

to be at its maximum. 

 (ii) The Regional Administrator may waive the requirement 

in paragraph 4.5(a) for monitoring near Pb sources if the state 

or, where appropriate, local agency can demonstrate the Pb 

source will not contribute to a maximum Pb concentration in 
41 

ambient air in excess of 50 percent of the NAAQS (based on 

historical monitoring data, modeling, or other means). The 

waiver must be renewed once every 5 years as part of the network 

assessment required under 58.10(d). 

 (b) State and, where appropriate, local agencies are 

required to conduct non-source-oriented Pb monitoring at each 

NCore site required under paragraph 3 of this appendix. 

 * * * * *