[Federal Register Volume 82, Number 127 (Wednesday, July 5, 2017)]
[Rules and Regulations]
[Pages 30955-30958]
[FR Doc No: 2017-14050]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0187; Directorate Identifier 2017-NE-08-AD;
Amendment 39-18893; AD 2017-10-19]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce plc Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Rolls-Royce plc (RR) Trent 1000-A2, Trent 1000-C2, Trent 1000-D2, Trent
1000-E2, Trent 1000-G2, Trent 1000-H2, Trent 1000-J2, Trent 1000-K2,
and Trent 1000-L2 turbofan engines. This AD requires initial and
repetitive on-wing inspections of affected intermediate pressure
compressor (IPC) rotor seals. This AD was prompted by a failure of the
IPC rotor seal. We are

issuing this AD to correct the unsafe condition on these products.

DATES: This AD becomes effective July 20, 2017.
    The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 20,
2017.
    We must receive comments on this AD by August 21, 2017.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Mail: U.S. Department of Transportation, 1200 New Jersey
Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC
20590-0001.
     Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax:<PHONE_NUMBER>.
    For service information identified in this AD, contact Rolls-Royce
plc, Corporate Communications, P.O. Box 31, Derby, England, DE24 8BJ;
phone: 011-44-1332-242424; fax: 011-44-1332-249936; email: http://www.rolls-royce.com/contact/civil_team.jsp; Internet: https://customers.rolls-royce.com/public/rollsroycecare. You may view this
service information at the FAA, Engine & Propeller Directorate, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call<PHONE_NUMBER>. It is also
available on the Internet at http://www.regulations.gov by searching
for and locating Docket No. FAA-2017-0187.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0187; or in person at the Docket Operations office between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays. The AD docket
contains this AD, the mandatory continuing airworthiness information
(MCAI), regulatory evaluation, any comments received, and other
information. The address for the Docket Office (phone:<PHONE_NUMBER>) is
in the ADDRESSES section. Comments will be available in the AD docket
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Robert Green, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200
District Avenue, Burlington, MA 01803; phone:<PHONE_NUMBER>; fax: 781-
238-7199; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Comments Invited

    This AD is a final rule that involves requirements affecting flight
safety, and we did not precede it by notice and opportunity for public
comment. We invite you to send any written relevant data, views, or
arguments about this AD. Send your comments to an address listed under
the ADDRESSES section. Include ``Docket No. FAA-2017-0187; Directorate
Identifier 2017-NE-08-AD'' at the beginning of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this AD. We will consider all
comments received by the closing date and may amend this AD because of
those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact
with FAA personnel concerning this AD.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
AD 2017-0017, dated February 1, 2017 (referred to hereinafter as ``the
MCAI''), to correct an unsafe condition for the specified products. The
MCAI states:

    Recently, a low speed abort (60 to 65 knots) occurred on take-
off on a Trent 1000-powered Boeing 787 aeroplane. The pilot
performed a commanded engine shutdown and the aeroplane safely
returned to the gate. Following investigation, failure and release
of the intermediate pressure compressor (IPC) rotor seal was
confirmed as having caused this event. RR have confirmed that other
IPC rotor seals, Part Number (P/N) KH19098, have been found with
cracking at the seal head. This condition, if not detected and
corrected, could lead to engine power loss, possibly resulting in
reduced control of the aeroplane.

    You may obtain further information by examining the MCAI in the AD
docket on the Internet at http://www.regulations.gov by searching for
and locating Docket No. FAA-2017-0187.

Related Service Information Under 1 CFR Part 51

    RR has issued Alert Non-Modification Service Bulletin (NMSB) Trent
1000 72-AJ467, Revision 1, dated February 13, 2017; and NMSB Trent 1000
72-J353, Revision 1, dated November 24, 2016. The Alert NMSB describes
procedures for initial and repetitive inspections of affected IPC rotor
seal. The NMSB describes procedures for in-shop inspections of affected
IPC rotor seals. This service information is reasonably available
because the interested parties have access to it through their normal
course of business or by the means identified in the ADDRESSES section.

FAA's Determination and Requirements of This AD

    This product has been approved by EASA, and is approved for
operation in the United States. Pursuant to our bilateral agreement
with the European Community, EASA has notified us of the unsafe
condition described in the MCAI and service information referenced
above. We are issuing this AD because we evaluated all information
provided by EASA and determined the unsafe condition exists and is
likely to exist or develop on other products of the same type design.
This AD requires initial and repetitive inspections of affected IPC
rotor seal for cracks.

FAA's Determination of the Effective Date

    No domestic operators use this product. Therefore, we find that
notice and opportunity for prior public comment are impracticable and
that good cause exists for making this amendment effective in less than
30 days.

Costs of Compliance

    We estimate that this AD affects 0 engines installed on airplanes
of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection of IPC rotor seal..........  12.5 work-hours x $85                 $0       $1,062.50              $0
                                         per hour = $1,062.50.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
    We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, Section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications
under Executive Order 13132. This AD will not have a substantial direct
effect 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.
    For the reasons discussed above, I certify this AD:
    (1) Is not a ``significant regulatory action'' under Executive
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska to the extent
that it justifies making a regulatory distinction, and
    (4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness
directive (AD):

2017-10-19 Rolls-Royce plc: Amendment 39-18893; Docket No. FAA-2017-
0187; Directorate Identifier 2017-NE-08-AD.

(a) Effective Date

    This AD is effective July 20, 2017.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Rolls-Royce plc (RR) Trent 1000-A2, Trent
1000-C2, Trent 1000-D2, Trent 1000-E2, Trent 1000-G2, Trent 1000-H2,
Trent 1000-J2, Trent 1000-K2, and Trent 1000-L2 turbofan engines
with intermediate pressure compressor (IPC) rotor seal, part number
(P/N) KH19098, installed.

(d) Subject

    Joint Aircraft System Component (JASC) 7230, Turbine Engine,
Compressor Section.

(e) Reason

    This AD was prompted by failure of the IPC rotor seal. We are
issuing this AD to prevent failure of the IPC rotor seal, loss of
engine thrust control, and reduced control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Required Actions

    (1) Perform an on-wing borescope inspection (BSI) of the IPC
rotor seal using paragraph 3, Accomplishment Instructions, of RR
Alert Non-Modification Service Bulletin (NMSB) Trent 1000 72-AJ467,
Revision 1, dated February 13, 2017 as follows:
    (i) For engines with an IPC rotor seal with 300 flight cycles
(FC) or more before August 2017, perform a BSI before August 2017.
    (ii) For engines with an IPC rotor seal with less than 300 FC
before August 2017, perform a BSI before the IPC rotor seal
accumulates 300 FC.
    (2) Depending on the findings of the inspection(s) required by
paragraph (g)(1) of this AD, repeat the on-wing BSI at intervals not
to exceed those specified in Figures 2 or 4 of RR Alert NMSB Trent
1000 72-AJ467, Revision 1, dated February 13, 2017.
    (3) An in-shop inspection in accordance with paragraph 3,
Accomplishment Instructions, of RR NMSB Trent 1000 72-J353, Revision
1, dated November 24, 2016, may be substituted for an on-wing BSI as
required by paragraphs (g)(1) and (2) of this AD, within the
compliance times specified.
    (4) After the effective date of this AD, do not operate an
aircraft, having two engines installed that are both subject to the
20 FC IPC rotor seal re-inspection interval specified in Figure 4 of
RR Alert NMSB Trent 1000 72-AJ467, Revision 1, dated February 13,
2017.
    (5) If, during an on-wing inspection as required by paragraphs
(g)(1) or (2) of this AD, or an in-shop inspection as specified in
paragraph (g)(3) of this AD, any crack is found on the rear face of
the affected IPC rotor seal that is at or beyond the reject limits
specified in Figure 4 of RR Alert NMSB Trent 1000 72-AJ467, Revision
1, dated February 13, 2017, replace the IPC rotor seal with a part
eligible for installation, before next flight.
    (6) Replacing the IPC rotor seal on an engine, as required by
paragraph (g)(5) of this AD, is not terminating action for the
inspections required by paragraphs (g)(1) and (2) of this AD for
that engine.
    (7) No reports requested in any of the Alert NMSBs that are
referenced in paragraphs (g)(1), (2), and (3) of this AD are
required by this AD.

(h) Credit for Previous Actions

    You may take credit for inspections and corrective action that
are required by paragraph (g) of this AD, if you performed these
actions and corrective action before the effective date of this AD,
using RR Alert NMSB Trent 1000 72-AJ467, Initial Issue, dated
November 9. 2016; or RR NMSB Trent 1000 72-J353, Initial Issue,
dated August 25, 2016, or Revision 1, dated November 24, 2016.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs
for this AD. Use the procedures found in 14 CFR 39.19 to make your
request. You may email your request to<EMAIL_ADDRESS>
(j) Related Information

    (1) For more information about this AD, contact Robert Green,
Aerospace Engineer, Engine Certification Office, FAA, Engine &
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803;
phone:<PHONE_NUMBER>; fax:<PHONE_NUMBER>; email<EMAIL_ADDRESS>    (2) Refer to MCAI AD 2017-0017, dated February 1, 2017, for more
information. You may examine the MCAI in the AD docket on the
Internet at http://www.regulations.gov by searching for and locating
it in Docket No. FAA-2017-0187.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
    (i) Rolls-Royce plc (RR) Non-Modification Service Bulletin
(NMSB) Trent 1000 72-J353, Revision 1, dated November 24, 2016.
    (ii) RR Alert NMSB Trent 1000 72-AJ467, Revision 1, dated
February 13, 2017.
    (3) For RR service information identified in this AD, contact
Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby,
England, DE24 8BJ; phone: 011-44-1332-242424; fax: 011-44-1332-
249936; email: http://www.rolls-royce.com/contact/civil_team.jsp;
Internet: https://customers.rolls-royce.com/public/rollsroycecare.
    (4) You may view this service information at FAA, Engine &
Propeller Directorate, 1200

District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call<PHONE_NUMBER>.
    (5) You may view this service information at the National
Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call<PHONE_NUMBER>, or go to:
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on May 11, 2017.
Robert J. Ganley,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 2017-14050 Filed 7-3-17; 8:45 am]
 BILLING CODE 4910-13-P


in the deficient months (i.e., bringing the data capture rate up to
100%), the computation yields a recalculated 3-month parameter mean
concentration equal or less than the level of the standard (0.15
µg/m3), then the 3-month mean is deemed to have passed the diagnostic
test and the level of the standard is deemed not to have been exceeded
in that 3-month period (for that parameter).  As noted in section
4(c)(ii), in such a case, the 3-month parameter mean of the data
actually reported, not the recalculated (“test”) result including
the high values, shall be used to determine the design value.

(d)  Months that do not meet the completeness criteria stated in 4(c)(i)
or 4(c)(ii), and design values that do not meet the completeness
criteria stated in 4(a) or 4(b), may also be considered valid (and
complete) with the approval of, or at the initiative of, the
Administrator, who may consider factors such as monitoring site
closures/moves, monitoring diligence, the consistency and levels of the
valid concentration measurements that are available, and nearby
concentrations in determining whether to use such data.

(e) The site-level design value for a 38-month period (three calendar
years plus two previous months) is identified from the available
(between one and 36) valid 3-month site means.  In a situation where
there are valid 3-month means for both parameters (Pb-TSP and Pb-PM10),
the mean originating from the reported Pb-TSP data will be the one
deemed the site-level monthly mean and used in design value
identifications unless the Pb-PM10 mean shows a violation of the NAAQS
and exceeds the Pb-TSP mean; see section 2(a) for details.  A monitoring
site will have only one site-level 3-month mean per 3-month period;
however, the set of site-level 3-month means considered for design value
identification (i.e., one to 36 site-level 3-month means) can be a
combination of Pb-TSP and Pb-PM10 data.

(f) The procedures for calculating monthly means and 3-month means, and
identifying Pb design values are given in section 6 of this appendix.

5. Rounding Conventions.

(a) Monthly means and monthly data capture rates are not rounded.

(b) Three-month means shall be rounded to the nearest hundredth µg/m3
(0.xx). Decimals 0.xx5 and greater are rounded up, and any decimal lower
than 0.xx5 is rounded down.  E.g., a 3-month mean of 0.104925 rounds to
0.10 and a 3-month mean of .10500 rounds to 0.11.   Three-month data
capture rates, expressed as a percent, are round to zero decimal places.

(c) Because a Pb design value is simply a (highest) 3-month mean and
because the NAAQS level is stated to two decimal places, no additional
rounding beyond what is specified for 3-month means is required before a
design value is compared to the NAAQS.

6.   Procedures and Equations for the Pb NAAQS.

(a)(i) A monthly mean value for Pb-TSP (or Pb-PM10) is determined by
averaging the daily values of a calendar month using equation 1 of this
appendix, unless the Administrator chooses to exercise his discretion to
use the alternate approach described in 6(a)(ii).

Equation 1

Where:

 Xm,y,s	=	the mean for month m of the year y for site s; and

nm	=	the number of daily values in the month (creditable plus extra
samples); and

Xi,m,y,s	=	The ith value in month m for year y for site s.

(a)(ii) The Administrator may at his discretion use the following
alternate approach to calculating the monthly mean concentration if the
number of extra sampling days during a month is greater than the number
of successfully completed scheduled and make-up sample days in that
month.  In exercising his discretion, the Administrator will consider
whether the approach specified in 6(a)(i) might in the Administrator’s
judgment result in an unrepresentative value for the monthly mean
concentration.  This provision is to protect the integrity of the
monthly and 3-month mean concentration values in situations in which, by
intention or otherwise, extra sampling days are concentrated in a period
during which ambient concentrations are particularly high or low.  The
alternate approach is to average all extra and make-up samples (in the
given month) taken after each scheduled sampling day (“Day X”) and
before the next scheduled sampling day (e.g., “Day X+6”, in the case
of one-in-six sampling) with the sample taken on Day X (assuming valid
data was obtained on the scheduled sampling day), and then averaging
these averages to calculate the monthly mean.  This approach has the
effect of giving approximately equal weight to periods during a month
that have equal number of days, regardless of how many samples were
actually obtained during the periods, thus mitigating the potential for
the monthly mean to be distorted.  The first day of scheduled sampling
typically will not fall on the first day of the calendar month, and
there may be make-up and/or extra samples (in that same calendar month)
preceding the first scheduled day of the month.  These samples will not
be shifted into the previous month’s mean concentration, but rather
will stay associated with their actual calendar month as follows.  Any
extra and make-up samples taken in a month before the first scheduled
sampling day of the month will be associated with and averaged with the
last scheduled sampling day of that same month.

(b) Three-month parameter means are determined by averaging three
consecutive monthly means of the same parameter using Equation 2 of this
appendix.

Equation 2

Where:

  EQ X\d\ba8()\s\up8(–)  m1, m2, m3; s	=	the 3-month parameter mean
for months m1, m2, and m3 for site s; and

nm	=	the number of monthly means available to be averaged (typically 3,
sometimes 1 or 2 if one or two months have no valid daily values); and

X m, y:z, s	=	The mean for month m of the year y (or z) for site s.

(c) Three-month site means are determined from available 3-month
parameter means according to the hierarchy established in 2(a) of this
appendix.

(d) The site-level Pb design value is the highest valid 3-month
site-level mean over the most recent 38-month period (i.e., the most
recent 3-year calendar period plus two previous months).  Section 4(a)
of this appendix explains when the identified design value is itself
considered valid for purposes of determining that the NAAQS is met or
violated at a site.

PART 51-REQUIREMENTS FOR PREPARATION, ADOPTION, AND, SUBMITTAL OF
IMPLEMENTATION PLANS

9  The authority citation for part 51 continues to read as follows:

Authority:  23 U.S.C. 101; 42 U.S.C. 7401-7671q

10.  Section 51.117 is amended by revising paragraph (e)(1) to read as
follows:

§ 51.117 Additional provisions for lead.

*****

(e) *****

(1) The point source inventory on which the summary of the baseline for
lead emissions inventory is based must contain all sources that emit 0.5
or more tons of lead per year.

*****

PART 53--AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS

11.  The authority citation for part 53 continues to read as follows:

Authority:   Sec. 301(a) of the Clean Air Act (42 U.S.C. sec. 1857g(a)),
as amended by sec. 15(c)(2) of Pub. L. 91–604, 84 Stat. 1713, unless
otherwise noted.

Subpart C-[AMENDED]

12.  Section 53.33 is revised to read as follows:

§53.33  Test Procedure for Methods for Lead (Pb).

(a) General. The reference method for Pb in TSP includes two parts, the
reference method for high-volume sampling of TSP as specified in 40 CFR
50, Appendix B and the analysis method for Pb in TSP as specified in 40
CFR 50, Appendix G. Correspondingly, the reference method for Pb in PM10
includes the reference method for low-volume sampling of PM10 in 40 CFR
50, Appendix O and the analysis method of Pb in PM10 as specified in 40
CFR 50, Appendix Q. This section explains the procedures for
demonstrating the equivalence of either a candidate method for Pb in TSP
to the high-volume reference methods, or a candidate method for Pb in
PM10 to the low-volume reference methods.

(1) Pb in TSP- A candidate method for Pb in TSP specifies reporting of
Pb concentrations in terms of standard temperature and pressure.
Comparisons of candidate methods to the reference method in 40 CFR 50,
Appendix G must be made in a consistent manner with regard to
temperature and pressure.

(2) Pb in PM10 -  A candidate method for Pb in PM10 must specify
reporting of Pb concentrations in terms of local conditions of
temperature and pressure, which will be compared to similarly reported
concentrations from the reference method in 40 CFR 50 Appendix Q.

(b) Comparability. Comparability is shown for Pb methods when the
differences between:

(1) Measurements made by a candidate method, and

(2) Measurements made by the reference method on simultaneously
collected Pb samples (or the same sample, if applicable), are less than
or equal to the values specified in table C–3 of this subpart.

(c) Test measurements. Test measurements may be made at any number of
test sites.  Augmentation of pollutant concentrations is not permitted,
hence an appropriate test site or sites must be selected to provide Pb
concentrations in the specified range.

(d) Collocated samplers. The ambient air intake points of all the
candidate and reference method collocated samplers shall be positioned
at the same height above the ground level, and between 2 meters (1 meter
for samplers with flow rates less than 200 liters per minute (L/min))
and 4 meters apart. The samplers shall be oriented in a manner that will
minimize spatial and wind directional effects on sample collection.

 	(e) Sample collection. Collect simultaneous 24-hour samples of Pb at
the test site or sites with both the reference and candidate methods
until at least 10 sample pairs have been obtained.

(1) A candidate method for Pb in TSP which employs a sampler and sample
collection procedure that are identical to the sampler and sample
collection procedure specified in the reference method in 40 CFR 50,
Appendix B, but uses a different analytical procedure than specified in
40 CFR Appendix G, may be tested by analyzing pairs of filter strips
taken from a single TSP reference sampler operated according to the
procedures specified by that reference method.

(2) A candidate method for Pb in PM10 which employs a sampler and sample
collection procedure that are identical to the sampler and sample
collection procedure specified in the reference method in 40 CFR 50,
Appendix O, but uses a different analytical procedure than specified in
40 CFR Appendix Q, requires the use of two PM10 reference samplers
because a single 46.2-mm filter from a reference sampler may not be
divided prior to analysis. It is possible to analyze a 46.2-mm filter
first with the non-destructive X-ray Fluorescence (XRF) FRM and
subsequently extract the filter for other analytical techniques. If the
filter is subject to XRF with subsequent extraction for other analyses,
then a single PM10 reference sampler may be used for sample collection.

(3) A candidate method for Pb in TSP or Pb in PM10 which employs a
direct reading (e.g., continuous or semi-continuous sampling) method
that uses the same sampling inlet and flow rate as the FRM and the same
or different analytical procedure may be tested.  The direct
measurements are then aggregated to 24-hour equivalent concentrations
for comparison with the FRM. For determining precision in section (k),
two collocated direct reading devices must be used.

(f) Audit samples.  Three audit samples must be obtained from the
address given in § 53.4(a). For Pb in TSP collected by the high-volume
sampling method, the audit samples are ¾ x 8-inch glass fiber strips
containing known amounts of Pb in micrograms per strip (μg/strip)
equivalent to the following nominal percentages of the National Ambient
Air Quality Standard (NAAQS): 30%, 100 %, and 250%. For Pb in PM10
collected by the low-volume sampling method, the audit samples are
46.2-mm polytetrafluorethylene (PTFE) filters containing known amounts
of Pb in micrograms per filter (µg/filter) equivalent to the same
percentages of the NAAQS: 30%, 100%, and 250%. The true amount of Pb
(Tqi), in total µg/strip (for TSP) or total µg/filter (for PM10), will
be provided for each audit sample.

(g) Filter analysis.

μg/m3 for each analysis of each filter. The analysis of replicates
should not be performed sequentially. Label these test results as C1A,
C1B, C2C, etc., where C denotes results from the candidate method. For
candidate methods which provide a direct reading or measurement of Pb
concentrations without a separable procedure, C1A=C1B=C1C, C2A=C2B=C2C,
etc.

(h) Average Pb concentration. For the reference method, calculate the
average Pb concentration for each filter by averaging the concentrations
calculated from the three analyses as described in (g)(1) using equation
1 of this section:

Equation 1

Where, i is the filter number.

(i) Analytical Bias.

(1) For the audit samples, calculate the average Pb concentration for
each strip or filter analyzed by the reference method by averaging the
concentrations calculated from the three analyses as described in (g)(1)
using equation 2 of this section:

	Equation 2

Where, i is audit sample number.

(2) Calculate the percent difference (Dq) between the average Pb
concentration for each audit sample and the true Pb concentration (Tq)
using equation 3 of this section:

Equation 3

(3) If any difference value (Dqi) exceeds ±5 percent, the bias of the
reference method analytical procedure is out-of-control. Corrective
action must be taken to determine the source of the error(s) (e.g.,
calibration standard discrepancies, extraction problems, etc.) and the
reference method and audit sample determinations must be repeated
according to paragraph (g) of this section, or the entire test procedure
(starting with paragraph (e) of this section) must be repeated.

(j) Acceptable filter pairs. Disregard all filter pairs for which the Pb
concentration, as determined in paragraph (h) of this section by the
average of the three reference method determinations, falls outside the
range of 30% to 250% of the Pb NAAQS level in µg/m3 for Pb in both TSP
and PM10. All remaining filter pairs must be subjected to the tests for
precision and comparability in paragraphs (k) and (l) of this section.
At least five filter pairs must be within the specified concentration
range for the tests to be valid.

(k) Test for precision.

(1) Calculate the precision (P) of the analysis (in percent) for each
filter and for each method, as the maximum minus the minimum divided by
the average of the three concentration values, using equation 4 or
equation 5 of this section:

Equation 4

or

	Equation 5

where, i indicates the filter number.

(2) If a direct reading candidate method is tested, the precision is
determined from collocated devices using equation 5 above.

 (3) If any reference method precision value (PRi) exceeds 15 percent,
the precision of the reference method analytical procedure is
out-of-control. Corrective action must be taken to determine the
source(s) of imprecision, and the reference method determinations must
be repeated according to paragraph (g) of this section, or the entire
test procedure (starting with paragraph (e) of this section) must be
repeated.

(4) If any candidate method precision value (PCi) exceeds 15 percent,
the candidate method fails the precision test.

(5) The candidate method passes this test if all precision values (i.e.,
all PRi's and all PCi's) are less than 15 percent.

(l) Test for comparability.

(1) For each filter or analytical sample pair, calculate all nine
possible percent differences (D) between the reference and candidate
methods, using all nine possible combinations of the three
determinations (A, B, and C) for each method using equation 6 of this
section:

Equation 6

where, i is the filter number, and n numbers from 1 to 9 for the nine
possible difference combinations for the three determinations for each
method (j = A, B, C, candidate; k = A, B, C, reference).

(2) If none of the percent differences (D) exceeds ±20 percent, the
candidate method passes the test for comparability.

(3) If one or more of the percent differences (D) exceed ±20 percent,
the candidate method fails the test for comparability.

(4) The candidate method must pass both the precision test (paragraph
(k) of this section) and the comparability test (paragraph (l) of this
section) to qualify for designation as an equivalent method.

(m) Method Detection Limit (MDL). Calculate the estimated MDL using the
guidance provided in 40 CFR, Part 136 Appendix B. It is essential that
all sample processing steps of the analytical method be included in the
determination of the method detection limit. Take a minimum of seven
blank filters from each lot to be used and calculate the detection limit
by processing each through the entire candidate analytical method. Make
all computations according to the defined method with the final results
in µg/m3. The MDL of the candidate method must be equal to, or less
than 5% of the level of the Pb NAAQS.

Table C–3 to Subpart C of Part 53—Test Specifications for Pb in TSP
and Pb in PM10 Methods

≤15%

Maximum difference (D) 	±20 %

Estimated Method Detection Limit (MDL), µg/m3	5 % of NAAQS level

PART 58--AMBIENT AIR QUALITY SURVEILLANCE

13.  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]

14.  Section 58.10, is amended by revising paragraph subsections (a)(4)
and adding paragraph (b)(9) to read as follows:

§ 58.10   Annual monitoring network plan and periodic network
assessment.

* * * * *

	(a) * * *

(4)  A plan for establishing Pb monitoring sites in accordance with the
requirements of appendix D to this part 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 to be
operational by January 1, 2010, and for all required nonsource-oriented
Pb monitoring sites to be operational by January 1, 2011.  Specific site
locations for the sites to be operational by January 1, 2011 are not
required as part of the July 1, 2009 annual network plan, but shall be
included in the annual network plan due to be submitted to the EPA
Regional Administrator on July 1, 2010.

* * * * *

(b) * * *

(9)  The designation of any Pb monitors as either source-oriented or
non-source oriented according to Appendix D to 40 CFR part 58.

(10)  Any source-oriented monitors for which a waiver has been requested
or granted by the EPA Regional Administrator as allowed for under
paragraph 4.5(a)(ii) of Appendix D to 40 CFR part 58.

(11)  Any source-oriented or nonsource-oriented site for which a waiver
has been requested or granted by the EPA Regional Administrator for the
use of Pb-PM10 monitoring in lieu of Pb-TSP monitoring as allowed for
under paragraph 2.10 of Appendix C to 40 CFR part 58.

* * * * *

17.  Section 58.13 is amended by revising paragraph (b) to read as
follows:

§ 58.13   Monitoring network completion.

* * * * *

(b) Not withstanding specific dates included in this part, beginning
January 1, 2008, when existing networks are not in conformance with the
minimum number of required monitors specified in this part, additional
required monitors must be identified in the next applicable annual
monitoring network plan, with monitoring operation beginning by January
1 of the following year.  To allow sufficient time to prepare and
comment on Annual Monitoring Network Plans, only monitoring requirements
effective 120 days prior to the required submission date of the plan
(i.e., 120 days prior to July 1 of each year) shall be included in that
year’s annual monitoring network plan.

18.  Section 58.16 is amended by revising paragraph (a) to read as
follows:

§ 58.16   Data submittal and archiving requirements.

(a) The State, or where appropriate, local agency, shall report to the
Administrator, via AQS all ambient air quality data and associated
quality assurance data for SO2; CO; O3; NO2; NO; NOY; NOX; Pb-TSP mass
concentration; Pb-PM10 mass concentration; PM10 mass concentration;
PM2.5 mass concentration; for filter-based PM2.5 FRM/FEM the field blank
mass, sampler-generated average daily temperature, and sampler-generated
average daily pressure; chemically speciated PM2.5 mass concentration
data; PM10–2.5 mass concentration; chemically speciated PM10–2.5
mass concentration data; meteorological data from NCore and PAMS sites;
average daily temperature and average daily pressure for Pb sites if not
already reported from sampler generated records; and metadata records
and information specified by the AQS Data Coding Manual
(http://www.epa.gov/ttn/airs/airsaqs/manuals/manuals.htm ).  The State,
or where appropriate, local agency, may report site specific
meteorological measurements generated by on site equipment
(meteorological instruments, or sampler generated) or measurements from
the nearest airport reporting ambient pressure and temperature.  Such
air quality data and information must be submitted directly to the AQS
via electronic transmission on the specified quarterly schedule
described in paragraph (b) of this section.

* * * * *

SUBPART D--[AMENDED]

19.  Section 58.20 is amended by revising paragraph (e) to read as
follows:

§ 58.20   Special purpose monitors (SPM).

* * * * *

(e) If an SPM using an FRM, FEM, or ARM is discontinued within 24 months
of start-up, the Administrator will not designate an area as
nonattainment for the CO, SO2, NO2, or 24-hour PM10 NAAQS solely on the
basis of data from the SPM. Such data are eligible for use in
determinations of whether a nonattainment area has attained one of these
NAAQS.

* * * * *

20.  Appendix A to Part 58 is amended to read as follows; (a) revising
paragraph 1, (b) inserting paragraph <IP_ADDRESS>, (c) revising paragraph
3.3.4, (d) revising paragraph 4c,  (e) revising paragraph 4.4, (f)
eliminating paragraph 4.5 and (g) revising Table A-2.

Appendix A to Part 58—Quality Assurance Requirements for SLAMS, SPMs
and PSD Air Monitoring

* * * * *

1. General Information

This appendix specifies the minimum quality system requirements
applicable to SLAMS air monitoring data and PSD data for the pollutants
SO2, NO2, O3, CO, Pb, PM2.5, PM10 and PM10-2.5 submitted to EPA.  This
appendix also applies to all SPM stations using FRM, FEM, or ARM methods
which also meet the requirements of Appendix E of this part. Monitoring
organizations are encouraged to develop and maintain quality systems
more extensive than the required minimums. The permit-granting authority
for PSD may require more frequent or more stringent requirements.
Monitoring organizations may, based on their quality objectives, develop
and maintain quality systems beyond the required minimum. Additional
guidance for the requirements reflected in this appendix can be found in
the “Quality Assurance Handbook for Air Pollution Measurement
Systems”, volume II, part 1 (see reference 10 of this appendix) and at
a national level in references 1, 2, and 3 of this appendix.

* * * * *

<IP_ADDRESS> Measurement Uncertainty for Pb Methods. The goal for acceptable
measurement uncertainty is defined for precision as an upper 90 percent
confidence limit for the coefficient variation (CV) of 20 percent and
for bias as an upper 95 percent confidence limit for the absolute bias
of 15 percent.

* * * * *

3.3.4  Pb Methods.

<IP_ADDRESS>   Flow Rates. For the Pb Reference Methods (40 CFR Part 50,
appendix G and appendix Q) and associated FEMs, the flow rates of the Pb
samplers shall be verified and audited using the same procedures
described in sections 3.3.2 and 3.3.3 of this appendix.

<IP_ADDRESS>  Pb Analysis Audits. Each calendar quarter or sampling quarter
(PSD), audit the Pb Reference Method analytical procedure using filters
containing a known quantity of Pb. These audit filters are prepared by
depositing a Pb solution on unexposed filters and allowing them to dry
thoroughly. The audit samples must be prepared using batches of reagents
different from those used to calibrate the Pb analytical equipment being
audited. Prepare audit samples in the following concentration ranges:

Range	Equivalent ambient Pb

concentration, µg/m3

1	30-100% of Pb NAAQS

2	200-300% of Pb NAAQS

(a) Audit samples must be extracted using the same extraction procedure
used for exposed filters.

(b) Analyze three audit samples in each of the two ranges each quarter
samples are analyzed. The audit sample analyses shall be distributed as
much as possible over the entire calendar quarter.

(c) Report the audit concentrations (in µg Pb/filter or strip) and the
corresponding measured concentrations (in µg Pb/filter or strip) using
AQS unit code 077. The percent differences between the concentrations
are used to calculate analytical accuracy as described in section 4.1.3
of this appendix.

(d) The audits of an equivalent Pb method are conducted and assessed in
the same manner as for the reference method. The flow auditing device
and Pb analysis audit samples must be compatible with the specific
requirements of the equivalent method.

<IP_ADDRESS>  Collocated Sampling.  The collocated sampling requirements for
Pb-TSP and Pb-PM10 shall be determined using the same procedures
described in sections 3.3.1 of this appendix with the exception that the
first collocated Pb site selected must be the site measuring the highest
Pb concentrations in the network. If the site is impractical,
alternative sites, approved by the EPA Regional Administrator, may be
selected. If additional collocated sites are necessary, collocated sites
may be chosen that reflect average ambient air Pb concentrations in the
network.

<IP_ADDRESS>   Pb Performance Evaluation Program (PEP) Procedures. Each
year, one performance evaluation audit, as described in section 3.2.7 of
this appendix, must be performed at one Pb site in each primary quality
assurance organization that has less than or equal to 5 sites and two
audits at primary quality assurance organizations with greater than 5
sites.  In addition, each year, four collocated samples from  primary
quality assurance organizations with less than or equal to 5 sites and
six collocated samples at primary quality assurance organizations with
greater than 5 sites must be sent to an independent laboratory, the same
laboratory as the performance evaluation audit, for analysis.

* * * * *

4.  Calculations for Data Quality Assessment

* * *

(c) At low concentrations, agreement between the measurements of
collocated samplers, expressed as relative percent difference or percent
difference, may be relatively poor. For this reason, collocated
measurement pairs are selected for use in the precision and bias
calculations only when both measurements are equal to or above the
following limits:

(1) TSP: 20 µg/m3.

(2) Pb: 0.02 µg/m3.

(3) PM10 (Hi-Vol): 15 µg/m3.

(4) PM10 (Lo-Vol): 3 µg/m3.

(5) PM10-2.5 and PM2.5: 3 µg/m3.

* * * * *

4.4 Statistics for the Assessment of Pb.

4.4.1  Precision Estimate. Follow the same procedures as described for
PM10 in section 4.2.1 of this appendix using the data from the
collocated instruments. The data pair would only be considered valid if
both concentrations are greater than the minimum values specified in
section 4(c) of this appendix.

4.4.2  Bias Estimate. For the Pb analysis audits described in section
<IP_ADDRESS> and the Pb Performance Evaluation Program described in section
<IP_ADDRESS>, follow the same procedure as described in section 4.1.3 for the
bias estimate.

4.4.3  Flow rate calculations. For the one point flow rate
verifications, follow the same procedures as described for PM10 in
section 4.2.2; for the flow rate audits, follow the same procedures as
described in section 4.2.3.

* * * * *

Table A–2 of Appendix A to Part 58. Minimum Data Assessment
Requirements for SLAMS Sites

1. 5 valid audits for primary QA orgs, with ≤ 5 sites

2. 8 valid audits for primary QA orgs, with > 5 sites

3. All samplers in 6 years	Over all 4 quarters	Primary sampler
concentration and performance evaluation sampler concentration.

Manual Methods

Collocated sampling PM10, TSP, PM10–2.5, PM2.5, Pb-TSP, Pb-PM10
Collocated samplers	15%	Every 12 days PSD—every 6 days	Primary sampler
concentration and duplicate sampler concentration.

Flow rate verification PM10(low Vol), PM10–2.5, PM2.5, Pb-PM10	Check
of sampler flow rate	Each sampler	Once every month	Audit flow rate and
measured flow rate indicated by the sampler.

Flow rate verification PM10(High-Vol), TSP, Pb-TSP	Check of sampler flow
rate	Each sampler	Once every quarter	Audit flow rate and measured flow
rate indicated by the sampler.

Semi-annual flow rate audit PM10, TSP, PM10–2.5, PM2.5, Pb-TSP,
Pb-PM10 	Check of sampler flow rate using independent standard	Each
sampler, all locations	Once every 6 months	Audit flow rate and measured
flow rate indicated by the sampler.

Pb audit strips Pb-TSP, Pb-PM10 	Check of analytical system with Pb
audit strips	Analytical	Each quarter	Actual concentration and audit
concentration.

Performance evaluation program PM2.5, PM10–2.5	Collocated samplers	1.
5 valid audits for primary QA orgs, with ≤ 5 sites

2. 8 valid audits for primary QA orgs, with ≥ 5 sites

3. All samplers in 6 years	Over all 4 quarters	Primary sampler
concentration and performance evaluation sampler concentration.

Performance evaluation program Pb-TSP, Pb-PM10 	Collocated samplers	1. 1
valid audits and 4 collocated samples for primary QA orgs, with ≤ 5
sites

2. 2 valid audits and 6 collocated  samples for primary QA orgs, with >
5 sites

	Over all 4 quarters	Primary sampler concentration and performance
evaluation sampler concentration. Primary sampler concentration and
duplicate sampler concentration

1Effective concentration for open path analyzers.

2Corrected concentration, if applicable, for open path analyzers.

21.  Appendix C to Part 58 is amended by adding paragraph 2.10 to read
as follows:

* * * * *

2.10 Use of Pb-PM10 at a SLAMS Sites.

2.10.1 The EPA Regional Administrator may approve the use of a Pb-PM10
FRM or Pb-PM10 FEM sampler in lieu of a Pb-TSP sampler as part of the
network plan required under part 58.10(a)(4) in the following cases.

<IP_ADDRESS> Pb-PM10 samplers can be approved for use at the
nonsource-oriented sites required under paragraph 4.5(b) of Appendix D
to part 58 if there is no existing monitoring data indicating that the
maximum arithmetic 3-month mean Pb concentration (either Pb-TSP or
Pb-PM10) at the site was equal to or greater than 0.10 micrograms per
cubic meter during the previous 3 years.

<IP_ADDRESS> Pb-PM10 samplers can be approved for use at source-oriented
sites required under paragraph 4.5(a) if the monitoring agency can
demonstrate (through modeling or historic monitoring data from the last
3 years) that Pb concentrations (either Pb-TSP or Pb-PM10) will not
equal or exceed 0.10 micrograms per cubic meter on an arithmetic 3-month
mean and the source is expected to emit a substantial majority of its Pb
in the fraction of PM with an aerodynamic diameter of less than or equal
to 10 micrometers.

2.10.2 The approval of a Pb-PM10 sampler in lieu of a Pb-TSP sampler as
allowed for in paragraph 2.10.1 above will be revoked if measured
Pb-PM10 concentrations equal or exceed 0.10 micrograms per cubic meter
on an arithmetic 3-month mean.  Monitoring agencies will have up to 6
months from the end of the 3-month period in which the arithmetic
3-month Pb-PM10 mean concentration equaled or exceeded 0.10 micrograms
per cubic meter to install and begin operation of a Pb-TSP sampler at
the site.

22.  Appendix D to Part 58 is amended by revising paragraph 4.5 to read
as follows:

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

* * * * *

4.5  Lead (Pb) Design Criteria. (a) State and, where appropriate,
local agencies are required to conduct ambient air Pb monitoring taking
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, the potential for population exposure, and logistics.  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 1.0 or more tons per year based on either the most
recent National Emission Inventory (  HYPERLINK
"http://www.epa.gov/ttn/chief/eiinformation.html"
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 ambient air in excess of 50%
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 Pb monitoring in each CBSA with a population equal to or greater
than 500,000 people as determined by  the latest available census
figures.  At a minimum, there must be one nonsource-oriented SLAMS site
located to measure neighborhood scale Pb concentrations in urban areas
impacted by re-entrained dust from roadways, closed industrial sources
which previously were significant sources of Pb, hazardous waste sites,
construction and demolition projects, and other fugitive dust sources of
Pb.

(c)  The EPA Regional Administrator may require additional monitoring
beyond the minimum monitoring requirements contained in 4.5(a) and
4.5(b) where the likelihood of Pb air quality violations is significant
or where the emissions density, topography, or population locations are
complex and varied.

(d) The most important spatial scales for source-oriented sites to
effectively characterize the emissions from point sources are microscale
and middle scale.  The most important spatial scale for
nonsource-oriented sites to characterize typical lead concentrations in
urban areas is the neighborhood scale.  Monitor siting should be
conducted in accordance with 4.5(a)(i) with respect to source-oriented
sites.

(1) 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.  Pb monitors in areas where the public
has access, and particularly children have access, are desirable because
of the higher sensitivity of children to exposures of elevated Pb
concentrations.

(2) 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 3 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.

(3) 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. Sites 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.

(d) Technical guidance is found in references 4 and 5 of this appendix.
These documents provide additional guidance on locating sites to meet
specific urban area monitoring objectives and should be used in locating
new sites or evaluating the adequacy of existing sites.

* * * * *

 The legislative history of section 109 indicates that a primary
standard is to be set at “the maximum permissible ambient air level .
. . which will protect the health of any [sensitive] group of the
population,” and that for this purpose “reference should be made to
a representative sample of persons comprising the sensitive group rather
than to a single person in such a group.” S. Rep. No. 91-1196, 91st
Cong., 2d Sess. 10 (1970)

 Welfare effects as defined in section 302(h) (42 U.S.C. 7602(h))
include, but are not limited to, “effects on soils, water, crops,
vegetation, man-made materials, animals, wildlife, weather, visibility
and climate, damage to and deterioration of property, and hazards to
transportation, as well as effects on economic values and on personal
comfort and well-being.”

    In considering whether the CAA allowed for economic considerations
to play a role in the promulgation of the NAAQS, the Supreme Court
rejected arguments that because many more factors than air pollution
might affect public health, EPA should consider compliance costs that
produce health losses in setting the NAAQS.  Whitman v. American
Trucking Associations, 531 U.S. at 466.  Thus, EPA may not take into
account possible public health impacts from the economic cost of
implementation.  Id.

 The “indicator” of a standard defines the chemical species or
mixture that is to be measured in determining whether an area attains
the standard.

 The “form” of a standard defines the air quality statistic that is
to be compared to the level of the standard in determining whether an
area attains the standard.

 As described in section II.A.2.a below the CDC stated in 2005 that no
“safe” threshold for blood Pb levels in young children has been
identified (CDC, 2005a).

 Co-chaired by the Secretary of the HHS and the Administrator of the
EPA, the Task Force consisted of representatives from 16 Federal
departments and agencies.

 See, e.g., “Implementation of the Mercury-Containing and Rechargeable
Battery Management Act”
http://www.epa.gov/epaoswer/hazwaste/recycle/battery.pdf and
“Municipal Solid Waste Generation, Recycling, and Disposal in the
United States: Facts and Figures for 2005”
http://www.epa.gov/epaoswer/osw/conserve/resources/msw-2005.pdf.

 The 5th percentile, geometric mean, and 95th percentile values for the
2003-2004 NHANES are 0.7, 1.8 and 5.1 μg/dL, respectively (Axelrad,
2008a,b).

 In general, air-related pathways include those pathways where Pb passes
through ambient air on its path from a source to human exposure.

 Weathering of outdoor Pb paint may also contribute to soil Pb levels
adjacent to the house.

 The exposure assessment for children performed for this review employed
available data and methods to develop estimates intended to inform a
characterization of these pathways (as described in the proposal and the
final Risk Assessment Report).

 Additionally, Pb freely crosses the placenta resulting in continued
fetal exposure throughout pregnancy, with that exposure increasing
during the latter half of pregnancy (CD, section 6.6.2).

 As described by the Advisory Committee on Childhood Lead Poisoning
Prevention, “In 1991, CDC defined the blood lead level (BLL) that
should prompt public health actions as 10 μg/dL.  Concurrently, CDC
also recognized that a BLL of 10 μg/dL did not define a threshold for
the harmful effects of lead.  Research conducted since 1991 has
strengthened the evidence that children’s physical and mental
development can be affected at BLLS <10 μg/dL” (ACCLPP, 2007).

in children with BLLs <10 μg/ dL and >10 μg/dL, so preventive lead
hazard control measures need not be deferred pending further research
findings or consensus.” [CDC, 2005a, p. 2]  CDC’s Advisory Committee
on Childhood Lead Poisoning Prevention recently provided recommendations
regarding interpreting and managing blood Pb levels below 10 μg/dL in
children and reducing childhood exposures to Pb (ACCLPP, 2007).

 This information documents a variation in mean blood Pb levels across
the various age groups monitored.  For example, mean blood Pb levels in
2001-2002 for ages 1-5, 6-11, 12-19 and greater than or equal to 20
years of age, are 1.70, 1.25, 0.94, and 1.56 µg/dL, respectively (CD,
p. 4-22).

 Ratios are presented in the form of 1:x, with the 1 representing air Pb
(in µg/m3) and x representing blood Pb (in µg/dL).  Description of
ratios as higher or lower refers to the values for x (i.e., the change
in blood Pb per unit of air Pb).  Slopes are presented as simply the
value of x.

 We note that the 2006 Criteria Document did not include a discussion of
more recent studies relating to air-to-blood ratios; more recent studies
were discussed in the Staff Paper, including discussion by CASAC in
their review of those documents.

 Brunekreef et al. (1984) discusses potential confounders to the
relationship between air Pb and blood Pb, recognizing that ideally all
possible confounders should be taken into account in deriving an
adjusted air-to-blood relationship from a community study.  The studies
cited here adjusted for parental education (Zielhuis et al., 1979), age
and race (Billick et al., 1979, 1980) and additionally measuring height
of air Pb (Billick et al., 1983); Brunekreef et al. (1984) used multiple
regression to control for several confounders.  The authors conclude
that “presentation of both unadjusted and (stepwise) adjusted
relationships is advisable, to allow insight in the range of possible
values for the relationship” (p. 83).  Unadjusted ratios were
presented for two of these studies, including ratios of 4.0 (Zielhuis et
al., 1979) and 18.5 (Brunekreef et al., 1983). The proposal noted that
the Brunekreef et al, 1983 study is subject to a number of sources of
uncertainty that could result in air-to-blood Pb ratios that are biased
high, including the potential for underestimating ambient air Pb levels
due to the use of low volume British Smoke air monitors and the
potential for higher historical ambient air Pb levels to have influenced
blood Pb levels (see Section V.B.1 of the 1989 Pb Staff Report for the
Pb NAAQS review, EPA, 1989).  In addition, the 1989 Staff Report notes
that the higher air-to-blood ratios obtained from this study could
reflect the relatively lower blood Pb levels seen across the study
population (compared with blood Pb levels reported in other studies from
that period).

 This study considered changes in ambient air Pb levels and associated
blood Pb levels over a five-year period which included closure of an
older Pb smelter and subsequent opening of a newer facility in 1997 and
a temporary (3 month) shutdown of all smelting activity in the summer of
2001. The author observed that the air-to-blood ratio for children in
the area over the full period was approximately 1:6. The author noted
limitations in the dataset associated with exposures in the second time
period, after the temporary shutdown of the facility in 2001, including
sampling of a different age group at that time and a shorter time period
(3 months) at these lower ambient air Pb levels prior to collection of
blood Pb levels. Consequently, EPA calculated an alternate air-to-blood
Pb ratio based on consideration for ambient air Pb and blood Pb
reductions in the first time period (after opening of the new facility
in 1997).

 In the publication, the author acknowledges that remedial programs
(e.g., community and home-based dust control and education) may have
been responsible for some of the blood Pb reduction seen during the
study period (1997 to 2001). However, the author points out that these
programs were in place in 1992 and he suggests that it is unlikely that
they contributed to the sudden drop in blood Pb levels occurring after
1997. In addition, the author describes a number of aspects of the
analysis which could have implications for air-to-blood ratios including
a tendency over time for children with lower blood Pb levels to not
return for testing, and inclusion of children aged 6 to 36 months in Pb
screening in 2001 (in contrast to the wider age range up to 60 months as
was done in previous years).

 EPA is not basing its decisions on these two studies, but notes that
these estimates are consistent with other studies that were included in
the 1986 and 2006 Criteria Documents and considered by CASAC and the
public.

 As with all studies, we note that there are strengths and limitations
for these two studies which may affect the specific magnitudes of the
reported ratios, but that the studies’ findings and trends are
generally consistent with the conclusions from the 1986 Criteria
Document.

 The CASAC Panel stated "The Schwartz and Pitcher analysis showed that
in 1978, the midpoint of the National Health and Nutrition Examination
Survey (NHANES) II, gasoline Pb was responsible for 9.1 μg/dL of blood
Pb in children. Their estimate is based on their coefficient of 2.14
μg/dL per 100 metric tons (MT) per day of gasoline use, and usage of
426 MT/day in 1976.  Between 1976 and when the phase-out of Pb from
gasoline was completed, air Pb concentrations in U.S. cities fell a
little less than 1 μg/m3 (24).  These two facts imply a ratio of 9-10
μg/dL per μg/m3 reduction in air Pb, taking all pathways into
account." (Henderson, 2007a, pp. D-2 to D-3).

 Air-to-blood ratios for the full study area of the primary Pb smelter
range from 1:3 to 1:7 across the range of alternative standard levels
from 1.5 down to 0.02 µg/m3 (USEPA, 2007b).

 Lead has been classified as a probable human carcinogen by the
International Agency for Research on Cancer (inorganic lead compounds),
based mainly on sufficient animal evidence, and as reasonably
anticipated to be a human carcinogen by the U.S. National Toxicology
Program (lead and lead compounds) (CD, Section 6.7.2).  U.S. EPA
considers Pb a probable carcinogen (  HYPERLINK
"http://www.epa.gov/iris/subst/0277.htm"
http://www.epa.gov/iris/subst/0277.htm ; CD, p. 6-195).

 At mean blood Pb levels, in children, on the order of 10 μg/dL, and
somewhat lower, associations have been found with effects to the immune
system, including altered macrophage activation, increased IgE levels
and associated increased risk for autoimmunity and asthma (CD, Sections
5.9, 6.8, and 8.4.6).

ss-sectional studies offer evidence that exposure to Pb affects the
intellectual attainment of preschool and school age children at blood Pb
levels <10 μg/dL (most clearly in the 5 to 10 μg/dL range, but, less
definitively, possibly lower).” (p. 6-269)

s that a doubling of blood-Pb level (e.g., from 5 to 10 μg/dL) is
associated with ~1.0 mm Hg increase in systolic blood pressure and ~0.6
mm Hg increase in diastolic pressure (CD, p. E-10).

 This level has variously been called an advisory level or level of
concern (http://www.atsdr.cdc.gov/csem/lead/pb_standards2.html).  In
addressing children’s blood Pb levels, CDC has stated “Specific
strategies that target screening to high-risk children are essential to
identify children with BLLs > 10 µg/dL.” (CDC, 2005, p.1)

 In consideration of the evidence from experimental animal studies with
regard to the issue of threshold for neurotoxic effects, the CD notes
that there is little evidence that allows for clear delineation of a
threshold, and that “blood-Pb levels associated with neurobehavioral
effects appear to be reasonably parallel between humans and animals at
reasonably comparable blood-Pb concentrations; and such effects appear
likely to occur in humans ranging down at least to 5-10 µg/dL, or
possibly lower (although the possibility of a threshold for such
neurotoxic effects cannot be ruled out at lower blood-Pb
concentrations)” (CD, p. 8-38).

 Further, neurological effects in general include behavioral effects,
such as delinquent behavior (CD, sections 6.2.6 and <IP_ADDRESS>), sensory
effects, such as those related to hearing and vision (CD, sections 6.2.7
and <IP_ADDRESS>), and deficits in neuromotor function (CD, p. 8-36).

 As an example, the Criteria Document states “although an increase of
a few mmHg in blood pressure might not be of concern for an
individual’s well-being, the same increase in the population mean
might be associated with substantial increases in the percentages of
individuals with values that are sufficiently extreme that they exceed
the criteria used to diagnose hypertension” (CD, p. 8-77).

 For example, for a population mean IQ of 100 (and standard deviation of
15), 2.3% of the population would score above 130, but a shift of the
population to a mean of 95 results in only 0.99% of the population
scoring above 130 (CD, pp. 8-81 to 8-82).

 The median of the concurrent blood Pb levels modeled was 9.7 µg/dL;
the 5th and 95th percentile values were 2.5 and 33.2 µg/dL,
respectively (Lanphear et al., 2005).

 The tests for cognitive function in these studies include
age-appropriate Wechsler intelligence tests (Lanphear et al., 2005;
Bellinger and Needleman, 2003), the Stanford-Binet intelligence test
(Canfield et al., 2003), the Test of Non-Verbal Intelligence (Al-Saleh
et al., 2001), an abbreviated form of the Wechsler tests (Kordas et al.,
2006) and the Bayley Scales of Infant Development (Tellez-Rojo et al.,
2006).  The Wechsler and Stanford-Binet tests are widely used to assess
neurocognitive function in children and adults, however, these tests are
not appropriate for children under age three.  For such children,
studies generally use the age-appropriate Bayley Scales of Infant
Development as a measure of cognitive development.

 In the Criteria Document analysis, the 10th percentile was chosen as a
common point of comparison for the loglinear (and linear) models at a
point prior to the lowest end of the blood Pb levels.

b concentration of 10 μg/dL rather than at 7.5 μg/dL, is a small
protection against applying an incorrectly rapid change (steep slope
with increasingly smaller effect as concentrations lower) to the
calculation" (USEPA, 2008).  We note here that the slope for the
less-than-10-µg/dL portion of the model used in the RRP analysis
(-0.88) is similar to the median for the slopes included in the Criteria
Document analysis of quantitative relationships for studies in which the
majority of blood Pb levels were below 10 µg/dL.

 This slope reflects effects on cognitive development in this cohort of
24-month old children based on the age-appropriate test described
earlier, and is similar in magnitude to slopes for the cohorts of older
children described here.  The strengths and limitations of this
age-appropriate test, the Mental Development Index (MDI) of the Bayley
Scales of Infant Development (BSID), were discussed in a letter to the
editor by Black and Baqui (2005).  The letter states that "the MDI is a
well-standardized, psychometrically strong measure of infant mental
development."  The MDI represents a complex integration of
empirically-derived cognitive skills, for example, sensory/perceptual
acuities, discriminations, and response; acquisition of object
constancy; memory learning and problem solving; vocalization and
beginning of verbal communication; and basis of abstract thinking. Black
and Baqui additionally state that although the MDI is one of the most
well-standardized, widely used assessment of infant mental development,
evidence indicates low predictive validity of the MDI for infants
younger than 24 months to subsequent measures of intelligence.  They
explain that the lack of continuity may be partially explained by "the
multidimensional and rapidly changing aspects of infant mental
development and by variations in performance during infancy, variations
in tasks used to measure intellectual functioning throughout childhood,
and variations in environmental challenges and opportunities that may
influence development."  Martin and Volkmar (2007) also noted that
correlations between BSID performance and subsequent IQ assessments were
variable, but they also reported high test-retest reliability and
validity, as indicated by the correlation coefficients of 0.83 to 0.91,
as well as high interrater reliability, correlation coefficient of 0.96,
for the MDI.  Therefore, the BSID has been found to be a reliable
indicator of current development and cognitive functioning of the
infant.  Martin and Volkmar (2007) further note that “for the most
part, performance on the BSID does not consistently predict later
cognitive measures, particularly when socioeconomic status and level of
functioning are controlled”.

 In this study, the slope for blood Pb levels between 5 and 10 μg/dL
(population mean blood Pb of 6.9 μg/dL; n=101) was -0.94 points per
μg/dL blood Pb but was not statistically significant, with a p value of
0.12.  The difference in the slope between the <5 µg/dL and the 5-10
µg/dL groups was not statistically significant (Tellez-Rojo et al.,
2006; Tellez-Rojo, 2008).

 The LLL function is the loglinear function from Lanphear et al. (2005),
with linearization at low exposures (as described in sections 2.1.5 and
<IP_ADDRESS> of the Risk Assessment Report).

 In their review of the final risk assessment, CASAC expressed strong
support, stating that “[t]he Final Risk Assessment report captures the
breadth of issues related to assessing the potential public health risk
associated with lead exposures; it competently documents the universe of
knowledge and interpretations of the literature on lead toxicity,
exposures, blood lead modeling and approaches for conducting risk
assessments for lead” (Henderson, 2008a, p. 4).

 CASAC advice on the design of the risk assessment is summarized in
section II.C.2.a of the proposal.

 A sixth case study (the secondary Pb smelter case study) is also
described in the Risk Assessment Report.  However, as discussed in
Section 4.3.1 of that document (USEPA, 2007a), significant limitations
in the approaches have contributed to large uncertainties in the
corresponding estimates.

 As the blood Pb model used in the risk assessment was limited in that
it did not accept inputs of a temporal time step shorter than annual
average, ratios of relationships in the available air monitoring data
between different statistical forms being considered for the standard
and an annual average were employed for the urban case studies (that did
not rely on dispersion modeling) as a method of simulating the temporal
variability in air Pb concentrations that occurs as a result of
meteorology, source and emissions characteristics.

 The current NAAQS scenario for the urban case studies assumes ambient
air Pb concentrations higher than those currently occurring in nearly
all urban areas nationally.  While it is extremely unlikely that Pb
concentrations in urban areas would rise to meet the current NAAQS and
there are limitations and uncertainties associated with the roll-up
procedure used for the location-specific urban case studies (as
described in Section II.C.2.h of the proposal), this scenario was
included for those case studies to provide perspective on potential
risks associated with raising levels to the point that the highest level
across the study area just meets the current NAAQS.  This scenario was
simulated for the location-specific urban case studies using a
proportional roll-up procedure.  For the general urban case study, the
maximum quarterly average ambient air concentration was set equal to the
current NAAQS.

 Current conditions for the three location-specific urban case studies
in terms of maximum quarterly average air Pb concentrations were 0.09,
0.14 and 0.36 µg/m3 for the study areas in Los Angeles, Chicago and
Cleveland, respectively.

 Similarly, since dietary Pb was included within “background”,
reductions in dietary Pb, e.g., as a result of reduced deposition to
crops, were also not simulated.

 In comparing total risk estimates between alternate NAAQS scenarios,
this aspect of the analysis will tend to underestimate the reductions in
risk associated with alternative NAAQS.  However, this does not mean
that overall risk has been underestimated.  The net effect of all
sources of uncertainty or bias in the analysis, which may also tend to
under- or overestimate risk, could not be quantified.

 The ratios increase as the level of the alternate standard decreases.
This reflects the nonlinearity in the Pb response, which is greater on a
per-unit basis for lower ambient air Pb levels.

 For the primary Pb smelter (full study area), for which limitations are
noted in section II.C.2.c of the proposal, the air-to-blood ratio
estimates, presented in section <IP_ADDRESS> of the Risk Assessment Report
(USEPA, 2007b), ranged from 1:3 to 1:7. As in the other case studies,
ratios are higher at lower ambient air Pb levels.  It is noted that the
underlying changes in both ambient air Pb and blood Pb across standard
levels are extremely small, introducing uncertainty into ratios derived
using these data.

 As shown in the presentation in the Staff Paper (section 4.4), risk
estimates for the LLL function are generally bounded by estimates based
on the other three C-R functions included in the assessment.

Because of greater uncertainty in characterizing high-end population
risk, and specifically related to pathway apportionment of IQ loss
estimates for high-end percentiles, results discussed here focus on
those for the population median.

 As noted in Table 2 below and sections II.C.2.d and II.C.2.h of the
proposal, with regard to associated limitations and uncertainties, a
proportional roll-up procedure was used to estimate air Pb
concentrations in this scenario for the location-specific case studies.

 The term “evidence-based” as used here refers to the drawing of
information directly from published studies, with specific attention to
those reviewed and described in the Criteria Document, and is distinct
from considerations that draw from the results of the quantitative
exposure and risk assessment.

 For example, as stated in the Criteria Document, “Fortunately, there
exists a large database of high quality studies on which to base
inferences regarding the relationship between Pb exposure and
neurodevelopment.  In addition, Pb has been extensively studied in
animal models at doses that closely approximate the human situation.
Experimental animal studies are not compromised by the possibility of
confounding by such factors as social class and correlated environmental
factors.  The enormous experimental animal literature that proves that
Pb at low levels causes neurobehavioral deficits and provides insights
into mechanisms must be considered when drawing causal inferences
(Bellinger, 2004; Davis et al., 1990; U.S. Environmental Protection
Agency, 1986a, 1990).” (CD, p. 6-75)

Đ

•

$

$

'

+

6

N

T

u

|

›

£

È

æ

è

í

’

“

”

•

›

½

Ê

Ë

ó

1ó

h

 h™

0J

 h™

0J

h“2

0J

0J

 h

0J

 h

j”

ö

h

\

]

h

i

i

i

hZ

hZ

hZ

hZ

gdZ

`„ÐgdZ

gdZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

hZ

搒Ǡ摧ᷴ}

”ÿ$	\

”ÿ$	\

e

e

Ž

Ó

ç

‘

”

•

Ì

ç

ö

þ

 he

 he

he

he

h

h

h

h7

h7

h7

h§

h<

葠ː摧䌴$Ѐĥ摧堥

 h

h

n

‚

Ú

>

V

›

hž1

h¬

h¬

h

h*

h*

h*

 h‡

 h

N

€

å

æ

è

t

u

·

¸

 hÍ

 h©

 h©

 hg

 h4?

7

옍)

옍)

옍)

Ç

È

É

B*

 ਀&䘋

㐀ۖĀ̊d搃昀Ĵ

㐀ۖĀ̊d搃昀Ĵ

B*

@

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

ˆ

@

䬀

hl

hl

 h›

H* h›

 h‚

F

F

 h‰

P

ù

封

封

 h±D

 h6R

A

A

;

ȶ

э

ߺ

஀

 hd

%

&

)

*

+

,

8

9

:

;

<

=

x

ð

ô

Ī

ŏ

ũ

ż

ƀ

ƈ

ƫ

Ƭ

¹

ß

Bß

á

â

ã

4

6

8

:

ú

ü

þ

\

x

€

‚

„

u

y

î

ï

/

0

z

|

ƒ

…

×

Ø

Ù

u

w

è

7€

/

×

#

Á+

6.

ð.

Ã0

*1

R2

o4

8

ì8

‘9

%;

ç;

è=

³>

ᜀè

ê

)

+

±

é

#

#

#

#

#

ù#

$

1$

2$

8$

‰$

Š$

Œ$

$

Ô$

Ú$

à$

á$

G%

H%

&

š&

’'

“'

)

)

*

 *

Š*

>Š*

Œ*

à*

À+

Á+

Â+

,

,

P,

Z,

–,

 ,

-

-

Š-

Œ-

°-

²-

6.

7.

9.

<.

P.

î.

ï.

ð.

ñ.

Q/

§0

Ã0

Ä0

*1

+1

R2

S2

T2

I3

Z3

ó3

ü3

o4

p4

q4

5

5

$6

%6

*6

96

7

ÿ7

8

8

„8

†8

¡8

¢8

£8

ì8

í8

‘9

’9

=’9

“9

%;

&;

ç;

è;

J<

Z<

è=

é=

³>

´>

¡?

¢?

·?

½?

ï?

(@

¯@

°@

áA

âA

 B

¹B

ºB

/C

0C

ÈC

ÉC

øD

ùD

$E

,E

-E

.E

1E

8E

9E

bE

cE

kE

nE

uE

‚E

¢E

ÐE

ÕE

F

F³>

¡?

¯@

áA

øD

᠀ the Staff Paper, the context for use of the air-to-blood ratio here
is a population being exposed at the level of the standard.

 As noted in the proposal (73 FR 29228), while blood Pb levels in U.S.
children have decreased notably since the late 1970s, newer studies have
investigated and reported associations of effects on the
neurodevelopment of children with these more recent blood Pb levels.

The current standard specifies the measurement of airborne Pb with a
high-volume TSP federal reference method (FRM) sampler with atomic
absorption spectrometry of a nitric acid extract from the filter for Pb,
or with an approved equivalent method (40 C.F.R §50.12, Appendix G).

 For simplicity, the discussion in this notice speaks as if PM10
samplers have a sharp size cut-off.  In reality, they have a size
selection behavior in which 50% of particles 10 microns in size are
captured, with a progressively higher capture rate for smaller particles
and a progressively lower capture rate for larger particles.  The ideal
capture efficiency curve for PM10 samplers specifies that particles
above 15 microns not be captured at all, although real samplers may
capture a very small percentage of particles above 15 microns.  TSP
samplers have 50% capture points in the range of 25 to 50 microns
(Wedding et al., 1977), which is broad enough to include virtually all
sizes of particles capable of being transported any significant distance
from their source except under extreme wind events.

 “Low-volume PM10 sampling” refers to sampling using any of a number
of monitor models that draw 16.67 liters/minute (1 m3 /hour) of air
through the filter, in contrast to “high-volume” sampling of either
TSP or PM10 in which the monitor draws 1500 liters/minute (90 m3 /hour).

 In this notice, we use “ultra-coarse” to refer to particles
collected by a TSP sampler but not by a PM10 sampler.  We note that
CASAC has variously also referred to these particles as “very
coarse” or “larger coarse-mode” particles.  This terminology is
consistent with the traditional usage of “fine” to refer to
particles collected by a PM2.5 sampler, and “coarse” to refer to
particles collected by a PM10 sampler but not by a PM2.5 sampler,
recognizing that there will be some overlap in the particle sizes in the
three types of collected material.

 Low-volume PM10 samplers are equipped with an omni-directional
(cylindrical) inlet, which reduces the effect of wind direction, and a
sharp particle separator which excludes most of the particles greater
than 10-15 microns in diameter whose collection efficiency is most
sensitive to wind speed.  Also, in low-volume samplers, the filter is
protected from post-sampling contamination.

 In their advice, CASAC recognized the potential for site-to-site
variability in the relationship between Pb-TSP and Pb-PM10 (Henderson,
2007a, 2007b).  They also stated in their September 2007 letter, “The
Panel urges that PM10 monitors, with appropriate adjustments, be used to
supplement the data.  …  A single quantitative adjustment factor could
be developed from a short period of collocated sampling at multiple
sites; or a PM10 Pb/TSP Pb ‘equivalency ratio’ could be determined
on a regional or site-specific basis”.

 Data from collocated TSP and PM2.5 monitors are generally presented in
the Staff Paper (section 2.3.5).

 As described in the proposal (73 FR29233), collocated data from
source-oriented sites were available from just three locations near
three different types of sources and include data from as long ago as
1988 (Schmidt and Cavender, 2008).  A limited amount of additional data
has been provided in comments on the proposal.

 The differing evidence and associated strength of the evidence for
these different effects is described in detail in the Criteria Document.

 For example, EPA recognizes today that “there is no level of Pb
exposure that can yet be identified, with confidence, as clearly not
being associated with some risk of deleterious health effects” (CD, p.
8-63).

 Lead accumulates in the body and is only slowly removed, with bone Pb
serving as a blood Pb source for years after exposure and as a source of
fetal Pb exposure during pregnancy (CD, sections <IP_ADDRESS> and <IP_ADDRESS>).

 The health evidence with regard to the susceptibility of the developing
fetus and infants is well documented in the evidence as described in the
1986 Criteria Document, the 1990 Supplement (e.g., chapter III) and the
2006 Criteria Document.  For example, “[n]eurobehavioral effects of
Pb-exposure early in development (during fetal, neonatal, and later
postnatal periods) in young infants and children (< 7 years old) have
been observed with remarkable consistency across numerous studies
involving varying study designs, different developmental assessment
protocols, and diverse populations.” (CD, p. E-9)

 These analyses incorporate the revised averaging method identified
above and discussed more fully in section IV below.

 Among the studies of Pb health effects, in which blood Pb level is
generally used as an index of exposure, the sources of exposure vary and
are inclusive of air-related sources of Pb such as smelters (e.g., CD,
chapter 6).

 As described in section II.E.3.a.ii of the proposal, the first set
focused on C-R functions from analyses involving population mean
concurrent blood Pb levels of approximately 3 µg/dL (closer to current
mean blood Pb levels in U.S. children).  The second set (CD, pp. 8-78 to
8-80) considered functions descriptive of the C-R relationship from a
larger set of studies that include population mean blood Pb levels
ranging from a mean of 3.3 up to a median of 9.7 µg/dL (see Table 1).

 In considering alternative levels for the standard within the
air-related IQ loss framework, the Agency focused on estimates using an
air-to-blood ratio of 1:5 and also provided IQ loss estimates using
higher and lower estimates (i.e., 1:3 and 1:7).

 In considering the risk estimates in light of IQ loss estimates based
on the air-related IQ loss evidence-based framework in the proposal, the
Agency focused on risk estimates for the general urban and primary Pb
smelter subarea case studies as these case studies generally represent
population exposures for more highly air-pathway exposed children
residing in small neighborhoods or localized residential areas with air
concentrations nearer the standard level being evaluated, as compared
to, the location-specific case studies in which populations have a
broader range of air-related exposures including many well below the
standard level being evaluated.

 Similarly, in the most recent reviews of the NAAQS for ozone and PM,
EPA recognized that the available epidemiological evidence neither
supports nor refutes the existence of thresholds at the population
level, while noting uncertainties and limitations in studies that make
discerning thresholds in populations difficult (e.g., 73 FR 16444, March
27, 2008; 71 FR 61158, October 17, 2006).

 Some commenters provided recommendations with regard to a level for a
Pb-PM10–based standard.  While these comments are instructive on that
issue, the Administrator has decided to retain the current indicator of
Pb-TSP, and therefore they do not need to be addressed here.

 EPA agrees that the study by Hayes et al. (1994), cited by CASAC and
commenters, presents an air-to-blood ratio greater 1:10, but notes that
we are not relying on this study in our decision as it has not been
reviewed as part of the Criteria Document or Staff Paper (as described
in Section I.C).

 A ratio of 1:5 was recommended by one of these commenters (Doe Run
Resources Corp.).

  See previous footnote regarding Hayes et al. (1994).

 Using the ratio of 1:7 identified above as central within the
reasonable range of air-to-blood ratios, the estimate of air-related
blood Pb associated with a standard level of 0.15 µg/m3 would be
approximately 1 µg/dL.  Adding this to the mean total blood Pb level
for the U.S. population would yield a mean total blood Pb estimate of
2.8 µg/dL.

 As noted above, we also recognize that blood Pb levels are expected to
further decline in response to this and other public health protection
actions, including those described above in section I.D.

 Further, in determining what level of estimated IQ loss should be used
for evaluating the results obtained from this specific evidence-based
framework, the Administrator is not determining that such an IQ loss is
appropriate for use in other contexts.

 For example, in considering a standard level of 0.2 µg/m3, we note
that the risk assessment provides estimates falling within the range of
1.2 to 3.2 points IQ loss for the general urban case study and <3.7 for
the primary Pb smelter subarea.  These estimates are inclusive of the
range of estimates for the 0.20 standard level presented in Table 4
based on the median C-R slope applied in the air-related IQ loss
framework.  As noted in section II.A.3.a above, these case studies,
based on the nature of the population exposures represented by them,
relate more closely to the air-related IQ loss evidence-based framework
than other case studies assessed.

 As explained below, under the proposal sufficiently complete Pb-TSP
data would take precedence over Pb-PM10 data, so not all Pb-PM10 data
would necessarily be actually used in the design value calculations.

In the final Appendix R, there is a provision to calculate a
“3-month” average based on only one (or two) months of data if two
(or one) of the months in the 3-month period have no valid reported data
at all.  In this case, the sum of the available monthly averages is
divided by the number of months contributing data.  Because a lack of
data for an entire month (or two) would mean that the completeness over
a 3-month period cannot be higher than 67 percent (or 33 percent), which
is less than the normal requirement for 75 percent completeness, a
situation like this could result in a valid 3-month average
concentration only via application of the “above NAAQS” diagnostic
data substitution tests described in section IV.C.  With that test, if
substituting historically low data for the month (or two months) of
missing data still results in a 3-month average above the level of the
NAAQS, then the 3-month mean computed from only two (or one) months of
data is deemed valid and complete.

 The scheduled sampling days, in contrast, are expected to be
uncorrelated with Pb concentration, since they do not emphasize any
particular day of the week.

 Incomplete data for one month of a 3-year period would not necessarily
prevent a finding of a NAAQS violation, because a single 3-month average
concentration above the NAAQS level in any period not affected by that
month’s incompleteness would constitute a violation.

 No public comment was received on this provision.

 Comments regarding whether Pb-TSP or Pb-PM10 should be the indicator
for the NAAQS and EPA’s response to them are discussed in section
II.C.1.

 Scaling Factor: PM10 versus TSP,  Neptune and Company, Inc., Final
Report, September 30, 2008.

 The issues include but are not limited to the following: the available
paired data sets with enough pairs of data to apply the criteria are all
from sites where Pb-TSP concentrations were well below the final level
of the revised NAAQS so there is uncertainty about how well they
represent sites for which the accuracy of the scaling factor is critical
to compliance with or violation of the NAAQS; many of the available data
sets were not able to meet the proposed criteria for the correlation
between parameters and for consistency of the ratio between parameter
averages from month to month, meaning that no valid scaling factors
could be derived following the terms of the proposed Appendix R; the
proposed methods are sensitive to how measurements below the method
detection limit are reported and it is not clear how this reporting was
done in the available sets of paired data, and EPA did not propose any
particular reporting conventions for public comment; the site-specific
scaling factors in some cases varied from year to year in those few
cases where more than one year had enough pairs of data; and there are
indications that a linear relationship between the two parameters with a
non-zero intercept may be a better representation than a scaling factor
which inherently presumes a zero intercept.

 The consultant’s report does not characterize the orientation of the
monitoring sites, but based on other information it appears that sites
060250005, 260770905, and 261390009 are non-source oriented.

 Of 20 sites with paired data which EPA believed at the time of the
proposal to not be influenced by nearby industrial sources, only 3 had
ratios of average concentrations of Pb-TSP to Pb-PM10 greater than 1.4.
One of these sites had only 13 data pairs.  The other two sites had very
low concentrations of both parameters, such that the ratio may reflect
the influence of data rounding/truncation or censoring of data below the
method detection limit more than actual atmospheric concentration
ratios. Also, these paired data were from 2001 or earlier. (Development
of Pb-PM10 to Pb-TSP Scaling Factors, Mark Schmidt, 4/22/08.)  Also, as
noted above, the data from these sites are not adequate for the
development of site-specific scaling factors if the proposed criteria
for such data are applied to them.

 M. Schmidt and P. Lorang (October 15, 2008). Memo to Lead NAAQS Docket,
Analysis of Expected Range of Pb-TSP Concentrations at Non-Source
Oriented Monitoring Sites in CBSAs with Population Over 500,000.

 Based on the analysis described in the memo referenced in the previous
footnote, EPA estimates that this provision might have the effect of
prohibiting the use of Pb-PM10 monitoring for at most only a few
existing Pb monitoring sites which otherwise might be eligible for
Pb-PM10 monitoring instead of Pb-TSP monitoring.

 When the Pb-TSP monitor is installed, the monitoring agency would have
the option of discontinuing the Pb-PM10 monitor, and we expect that most
agencies would do so for cost reasons.

 If three years of Pb-TSP monitoring results in no 3-month average Pb
concentration equal to or greater than 0.10 µg/m3, as might occur after
the source improves its control of Pb emissions, the site would again be
eligible for Pb-PM10 monitoring.

 Such a comparison based on actual Pb-TSP data would of course be able
to support a compliance conclusion, because Pb-TSP is the actual
indicator for the NAAQS.

 Only a handful of low-volume Pb-PM10 monitoring sites are now
operational none of which indicate NAAQS violations. In addition, any
sites which begin operation in response to the final monitoring
requirements cannot collect three years of data by the time designations
must be completed.

 It is also possible for a period of less than three years to have a
valid design value, but only if the procedures in Appendix R when
applied to that shorter period result in a design value greater than the
level of the NAAQS.  It is possible to establish a violation of the
NAAQS on a monitoring period as short as three months but three years
are needed to establish compliance with the NAAQS.

 A violation will exist as soon as any 3-month average exceeds the level
of the NAAQS.  It is not required that three years of data collection be
completed before a site can be found in violation.  This is consistent
with the proposal.

 The FRM specification in the new Appendix Q for Pb-PM10 monitoring
excludes the possibility of composite sampling for Pb-PM10, so this in
an issue that applies only to Pb-TSP.

 The pollutant occurrence code is a numerical code (1, 2, 3, etc.) used
to distinguish the data from two or more monitors for the same parameter
at a single monitoring site.  For example, if a monitoring agency has
been using both composite analysis for filters from one sampler and
individual sample analysis for filters from a collocated sampler, data
from these would be distinguished using this code.  Choosing which set
of data to use based on which has the lower code value is an approach
chosen for its simplicity, to avoid specifying what would have to be a
complicated set of procedures to determine which set of data or
combination of the two sets actually is the more robust for determining
whether the NAAQS is met.

 For a list of currently approved FRM/FEMs for Pb-TSP refer to:
www.epa.gov/ttn/amtic/criteria.html

 The 21 distinct approved FEMs represent less than 21 fundamentally
different analysis methods, as some differ only in minor aspects.

 Sampling efficiency refers to the percentage of total Pb (or PM) that
is collected by the sampler.  For the TSP sampler, research shows that
the sampling efficiency varies for particulates greater than PM10 as a
function of wind speed and wind direction.

 Proper characterization of a new Pb-TSP FRM sampler would require
extensive wind-tunnel testing and field testing.  Wind tunnel testing
would be complicated by the difficulty in quantifiably generating and
delivering precise amounts of ultra-coarse PM in a wind-tunnel setting.

 For the complete definition of CBSA refer to:
ww.census.gov/population/www/estimates/aboutmetro.html

 Required PM2.5 sites have additional criteria where monitoring sites
are to represent community-wide air quality [40 CFR part 58, appendix D
paragraph 4.7.1(b)] with at least one required site in a
population-oriented area of expected maximum concentration.

 American Petroleum Institute v. Costle, 609 F.2d 20 (D.C. Cir. 1979)

 Under the CAA and the Tribal Authority Rule (TAR), eligible Indian
Tribes may develop and submit Tribal Implementation Plans (TIPs) for EPA
approval, to administer requirements under the CAA on their reservations
and in nonreservation areas under their jurisdiction.  However, Tribes
are not required to develop TIPs or otherwise implement relevant
programs under the CAA.  In cases where a Tribal air quality agency has
implemented an air quality monitoring network which is affected by Pb
emissions, the criteria and procedures identified in this rule may be
applied for regulatory purposes.  Certain Tribes may implement all
relevant components of an air quality program for purposes of meeting
the various requirements of this rule.

  Two elements identified in section 110(a)(2) are not listed below
because, as EPA interprets the CAA,  SIPs incorporating any necessary
local nonattainment area controls would not be due within 3 years, but
rather are due at the time the nonattainment area planning requirements
are due.  These elements are: (1) Emission limits and other control
measures, section 110(a)(2)(A), and (2) Provisions for meeting part D,
section 110(a)(2)(I), which requires areas designated as nonattainment
to meet the applicable nonattainment planning requirements of part D,
title I of the CAA.

 EPA Air Pollution Control Cost Manual - Sixth Edition (EPA
452/B-02-001), EPA Office of Air Quality Planning and Standards,
Research Triangle Park, NC, Jan 2002.

  See for example, 44 FR 53762 (September 17, 1979) and footnote 3 of
that notice.  Note that EPA’s emissions trading policy statement has
clarified that the RACT requirement may be satisfied by achieving
“RACT equivalent” emission reductions in the aggregate from the full
set of existing stationary sources in the area. See also EPA’s
economic incentive proposal which reflects the Agency’s policy
guidance with respect to emissions trading, 58 FR 11110, February 23,
1993.

 As previously stated in the proposed rule, EPA believes that most lead
nonattainment problems will most likely be due to emissions from
stationary sources of lead.  For this reason EPA believes that the RFP
for Pb should parallel the RFP policy for SO2 (see General Preamble, 57
FR 13545, April 16, 1992).

 The terms “major” and “minor” define the size of a stationary
source, for applicability purposes, in terms of an annual emissions rate
(tons per year, tpy) for a pollutant.  Generally, a minor source is any
source that is not “major.”  “Major” is defined by the
applicable regulations—PSD or nonattainment NSR.

 In addition, the PSD program applies to non-criteria pollutants subject
to regulation under the Act, except those pollutants regulated under
section 112 and pollutants subject to regulation only under section
211(o).

.

 Criteria pollutants are those pollutants for which EPA has established
a NAAQS under section 109 of the CAA.

 Transportation conformity is required under CAA section 176(c) (42
U.S.C. 7506(c) to ensure that federally supported highway and transit
project activities are consistent with (“conform to”) the purpose of
the SIP.  Transportation conformity applies to areas that are designated
nonattainment, and those areas redesignated to attainment after 1990
(“maintenance areas” with plans developed under CAA section 175A)
for transportation-related criteria pollutants.  In light of the
elimination of Pb additives from gasoline, transportation conformity
does not apply to the Pb NAAQS.

 The areas that are currently nonattainment for the pre-existing Pb
NAAQS are East Helena, Montana and Jefferson County (part)/Herculaneum,
Missouri. ( See http://www.epa.gov/oar/oaqps/greenbk/lnc.html)

  These are examples of available systems and is not an all inclusive
list. The mention of commercial products does not imply endorsement by
the U.S. Environmental Protection Agency.

഍倓䝁⁅ᔠ

഍ግ䅐䕇†ㄔക഍഍഍倓䝁⁅ᔠ

഍ግ䅐䕇†㐔㌱ക഍敒楶睥漠桴䅎允⁓潦⁲敌摡ⴠ
瀠条–䅐䕇ᐠ㔳ᔳ漠–啎偍䝁卅ᐠㄴᔳ഍഍ግ䔠䉍
䑅䔠畱瑡潩⹮″ᐠᔁ഍–䵅䕂⁄煅慵楴湯㌮†Ĕക഍