UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street Philadelphia, Pennsylvania 19103

DATE: February 6, 2014

SUBJECT: T echnical Support Document for the Pittsburgh Area’s Ca rbon Monoxide Second

Limited Maintenance Plan

FROM: Emlyn Vélez

- Rosa , E nvironmental Engineer

Office of Air Program Planning

TO: File \ s \

THRU: Cristina Fernandez

, Associate Director

Office of Air Program Planning

I

. I NTRODUCTION

On July 18

, 2011, the Commonwealth of Pennsylvania (“the Commonwealth”) submitted a

revi sion to the Pennsylvania State Implementation Plan (SIP )

, containing a carbon m onoxide (CO) second maintenance p lan for the Pittsburgh Area, which is comprised by portions of Allegheny County. The SIP revision was supplemented on November 26, 2013. The S IP

revision ensures maintenance of the CO National Ambient Air Quality Standards (NAAQS) in portions of t he Allegheny County for a second ten

- year period

, from 2013 to 2022.

II . BACKGROUND

A

. Designations

Carbon monoxide is a colorless, odorless gas emitted from combustion processes. Nationally and, particularly in urban areas, the majority of CO emissions to ambient air come from mobile

sources. CO can cause harmful health effects by reducing oxygen delivery to the body's organs (like the heart and brain) and tissues. At extremely high levels, CO can cause death.

The U.S. Environmental Protection Agency ( EPA ) initially established the CO NAAQS on April 30, 1971 (36 FR 8186)

. The primary standards, protective of public health, were se t at 9 p arts per million (ppm) as an 8

- hour average, and 35 ppm, as a 1

- hour average, neither to be exceeded more than once per year

. Later in 1971, EPA set the secondary standards identical to the primary

standards for protection of the public welfare

. See 40 C FR 50.8

. In a review of the standards completed in 1985 ( 50 FR 37484

, September 13, 1985 ), EPA retained the primary standard, but2

revoked the secondary standard due to lack of evidence of direct adverse effect on public welfare

at or near ambient concentr ations. Although the air quality criteria have changed over the past two decades, the CO primary standard ha s been retained without revision.

O n September 12, 1978 (43 FR 40513)

, EPA designated for the first time p ortions of Allegheny County as a CO no nattainment are a , referred to as the Pittsburgh Area . The Pittsburgh Area was defined to include the high traffic de nsity areas within Central Business District of Allegheny County and certain other high traffic density areas. T he C entral Business Distri ct is defined as the area enclosed by the Allegheny Riv er, the Monongahela River, and 579 interstate highway

, while “the other high traffic density areas” are defined as the Oakland neighborhood of Pittsburgh , Pennsylvania

.

In the 1990 Amendments, U.S. Co ngress added a provision under section 186(a) of the Clean Air Act (CAA) which authorized EPA to classify nonattainment areas according to the degree of severity of the nonattainment problem. Specifically, CAA section 186(a)(1) provides that each

area des ignated nonattainment for CO should be classified at the time of such designation as “Moderate” (9.1

- 16.4 ppm) or “Serious” (16.5 ppm and above) based on the design value of the

area. Additionally, under section 107(d)(a)(C), at the date of enactment of the CAA

A mendments , all areas of the country were designate d with respect to ozone and CO in accordance with the pre

- enactment designations by operation of the law

.

On November 6, 1991 (56 FR 56694) , EPA made final designation s and classifications for a ll areas in the country for all the six criteria pollutants. The d esignations and classifications for CO (post

- enactment of 1990 CAA Amendments ) were based on quality assured monitoring data for

years 1988

- 1989. The Pittsburgh Area maintained its pre

- ena ctment designation as a CO nonattainment area by operation of law. In this designation process, EPA determine d that the Pittsburgh Area was a “nonclassifiable ” area with respect CO NAAQS

, based on the fact that the

1988

- 1989 air quality design values for the Area were below the lowest CO nonattainment
classification of “Moderate ” (below 9.1 ppm).

B

. Compliance with CO NAAQS

A monitor is meeting the CO NAAQS if over a 2

- year period the second

- highest 1

- hour value is less than or equal to 35 ppm, and th e second

- highest, non

- overlapping 8

- hour value is less than or equal to 9 ppm. The s e calculated values are referred as the 1

- hour and the 8

- hour design

value , respectively

. A design value is calculated to compare to the NAAQS and determine compliance. T he CO design values are usually discussed in terms of the 8

- hour CO NAAQS,

rather tha n the 1

- hour NAAQS, because the 8

- hour NAAQS is typically the standard of concern. The design value of an area is the highest site

- specific design value of the monitors l ocated

within the area

. A CO nonattainment area is considered for redesignation if the design value of the Area is below the standards, that is, if there are no violations of the CO NAAQS for two consecutive years

. The method for calculating CO design va lues is presented in detail in EPA’s June 18, 1990 memorandum, “Ozone and Carbon Monoxide Design Value Calculations.”3

C. R edesignation to Attainment and Maintenance Plan

EPA may redesignate areas to attainment if sufficient monitoring data are availabl e to warrant such change and the area meets the criteria contained in section 107(d)(3)(E) of the CAA. These

criteria include , among others, a full approval of a maintenance plan that covers at least 10 years after redesignation, and meets the requirement s of section 175A of the CAA

. In addition, section

175A of the CAA require s tates to submit a revision to the maintenance plan eight years after redesignation to provide for maintenance of the NAAQS for 10 years following the end of the

first 10

- year main tenance period

. To address potential future NAAQS violations, the

maintenance plan must contain contingency measures, with a schedule for implementation adequate to assure prompt correction of any air quality problems.

On August 17, 2001, the Commonweal th submitted to EPA a redesignation request and a maintenance plan for the Pittsburgh Area for the CO NAAQS

. EPA allowed the Commonwealth to develop a “ limited maintenance p lan ” (LMP) for the Pittsburgh Area in addressing the maintenance plan requirements , and thus meeting the applicable requirements for redesignation. According to EPA ’s October 6, 1995 guidance “Limited Maintenance Plan Option for Nonclassifiable CO Nonattainment Areas,” the LMP option is only available to nonclassifiable

CO nonattainmen t areas with design values at or below the 85 percent (%) of the level of the 8

- hour CO NAAQS, or 7.65 ppm. The LMP option allows the areas meeting this requirement to submit a less rigorous maintenance plan than generally required for the CO NAAQS

. Sinc e the Pittsburgh Area was designated as a “nonclassifiable” nonattainment area and the Area’s 8

- hour design value at the time of redesignation was 3.9 ppm
, based on 1998

- 1999

, EPA concurred with the Commonwealth’s determination of submitting an LMP for the Area. On November 12, 2002 ( 67 FR 68521 ) , EPA granted the Commonwealth’s redesignation request and approved as a SIP

revision the maintenance plan for the Pittsburgh Area

. The SIP revision ensured maintenance of the standard until January 2013.

On Ju ly 18, 2011

, the Pennsylvania Department of Environmental Protection (PADEP)

submitted

, on behalf of Allegheny County Health Department (ACHD), as a SIP revision a second 10

- year CO maintenance plan for the Pittsburgh Area

. In recognition of the continuin g record of monitoring data showing ambient CO 8

- hour concentrations in the Pittsburgh Area well

below 7 .65 ppm, ACHD once more chose the LMP option for the development of this second maintenance plan. Further discussion of the maintenance plan requiremen ts and the LMP option is provided in section III of this document.

III

. EPA’S REQUIREMENTS

Section 175A defines the general framework of a maintenance plan. The maintenance plan will constitute a SIP revision and must provide for maintenance of the relevant NAAQS for at least 10 years after redesgination. Section 175A further states that the plan shall contain such4

additional measures, if any, as may be necessary to ensure such maintenance. In addition, the maintenance plan should contain such cont ingency measures as EPA deems necessary to ensure prompt correction or any violation of the NAAQS.

According to EPA’s September 4, 1992 Guidance Memorandum “ Procedures for Processing Requests to Redesignate Areas to Attainment, ” the following requiremen ts should be addressed by a maintenance plan: (1) Attainment Inventory : The state should develop an attainment emissions inventory to identify the level of emissions in the area which is sufficient to attain the NAAQS. This inventory should be consistent w ith EPA’s most recent guidance on emissions inventories for nonattainment areas available at the time and should include the emissions during the time period associated with the monitoring data showing attainment. Emissions of CO are generally expected to be the highest during the winter season. Thus, f or CO nonattainment areas, the inventory should be based on actual “typical winter day”

emissions for the time period associated with the monitoring data showing attainment of

the standard

. For more inform ation on developing seasonal CO emissions inventories,
refer to EPA’s guidance documents “Emissions Inventory Requirements for Carbon Monoxide State Implementation Plans” (EPA

- 450/4

- 91

- 011, March 1991) and

“ P rocedures for the Preparation of Emissions Inven tories for Carbon Monoxide and Precursors of Ozone; Volume I ” ( EPA

- 450/4

- 91

- 016 , May 1991)

.

(2) Maintenance Demonstration : A state may generally demonstrate maintenance of the NAAQS by either showing that the future emissions of a pollutant or its precursors will not exceed the level of the attainment inventory, or by modeling to show that the future

mix of sources and emission rates will not cause a violation of the NAAQS. In both instances, the demonstration should be for a period of 10 years following the redesignation. In either case, to satisfy the demonstration requirement the state should project emissions for the 10

- year period following redesignation. The projected inventory should consider future growth, should be consistent with the attainment in ventory, and should document data inputs and assumptions.

(3) Monitoring Netw o rk: The state should continue to operate an appropriate air quality monitoring network, in accordance with 40 CFR part 58, to verify the attainment status of

the area. The maint enance plan should contain provisions for continued operation of the air quality monitors that will provide such verification.

(4) Verification of Continued Attainment: Each state should ensure that it has the legal authority to implement and enforce all m easures necessary to attain and maintain the NAAQS. One measure to demonstrate attainment and maintenance is the acquisition of

ambient and air source emissions data. The state submittal should indicate how the state will track the progress of the mainte nance plan.

(5) Contingency Plan: The state is require d to adopt contingency provisions, as necessary,5

to promptly correct any violation of the NAAQS that occurs after redesignation of the area. In order for the maintenance plan to be approved, a state is n ot required to have full adopted contingency measures that will take effect without further action by the state; however, the contingency plan is considered to be an enforceable part of the SIP and should ensure that the contingency measures are adopted ex pediently once they are triggered. The plan should clearly identify the measures to be adopted, a schedule and procedure for adoption and implementation, and a specific time limit for action by the state. As necessary, the state should also identify spec ific indicators, or triggers, which will be used to determine when the contingency measures need to be implemented.

Additionally, transportation conformity requirements apply to nonattainment areas and maintenance areas operating under maintenance plans. Transportation conformity is required under section 176(c) of the CAA to ensure that federally supported highway, transit projects, and other activities are consistent with (conform to) the purpose of the SIP. The CAA requires

federal actions in nonattai nment and maintenance areas to “conform to” the goals of SIP. This means that such actions will not cause or contribute to violations of a NAAQS; worsen the severity of an existing violation; or delay timely attainment of any NAAQS or any interim

mileston e. EPA has established criteria and procedures for Federal agencies to follow in determining conformity of their actions. EPA’s rule governing transportation plans and Federally supported highway, transit projects, and other activities is referred to as the Transportation Conformity Rule (see 40 CFR part 93, subpart A), and EPA’s rule governing all other types of Federal agency actions is referred to as the General Conformity Rule (see 40 CFR part 93, subpart B).

Under the Transportation Conformity Rule, metropolitan planning organizations (MPOs) in nonattainment and maintenance areas coordinate with state air quality and transportation agencies, EPA, Federal Highway Administration (FHWA), and Federal Transit Administration (FTA) to demonstrate that their metropolitan transportation plans and transportation improvement plans conform to applicable SIPs. This is typically determined by showing that estimated emissions from existing and planned highway and transit systems are less than or equal

to the motor vehicle emissions budgets (MVEBs) contained in a SIP. For their maintenance

areas, states must submit to EPA motor vehicle emissions budgets (MVEBs) for the last year of the maintenance plan. As with nonattainment areas, all maintenance areas that submit emissions budgets would be allowed to use the budgets for conformity purposes after EPA finds the budget adequate.

Limited Maintenance Plan Option

For nonclassifiable CO areas seeking redesingation to attainment whose design value at the time of redesig nation is 85 percent or less than the 8

- hour CO NAAQS , or 7.65 ppm

, a state may
choose to submit a less rigorous maintenance plan than generally required . This option is termed a limited maintenance plan (LMP)

. EPA believes that the full maintenance plan requirements do not need to be applied to these areas because they have achieved air quality levels well below the6

standard without application of control measures required by the CAA for moderate and serious nonattainment areas. Also, these areas do not have either a recent history of monitored violations of the CO NAAQS or a long prior history of monitored air quality problems. Therefore, EPA

believes that f

or a limited maintenance area, the air quality along with the continued applicability

of prevent ion of significant deterioration ( PSD ) permitting requirements, any control measures already in the SIP, and Federal measures, should provide adequate assurance of maintenance over

the10

- year maintenance period. The same applies for areas submitting their second maintenance plans.

To qualify for the LMP option , the CO design value for the area, based on the eight consecutive quarters ( two years of data) used to demonstrate attainment must be at or below 7.65 pm for the

8

- hour CO NAAQS. Additionally, the design value for the area must continue to be at or below the 7.65 pm for the 8

- hour CO NAAQS until the time of EPA ’s final action.

According to EPA ’s October 6, 1995 guidance “Limited Maintenance Plan Option for Non

classifiable CO Nonattainment Areas, ” a LMP submittal must include the following :

(1) Attainment emission i nventory : Th e same requirement continues to apply.

(2) Maintenance demonstration: In an LMP

, t he maintenance demonstration requirement

is considered to be satisfied if the monitor ing data show that the area is meeting the air quality criteria for limited maintenance area, 7.65 ppm. The design value requirement is expected to provide adequate assurance of maintenance over the 10

- year period. The

mainten ance demonstration does not require to project emissions over the maintenance period.

(3) Monitoring Network and Verification of Continued Attainment : In an LMP, t o verify the attainment status of the area over the maintenance period, t he state must show continuous operation of an appropriate EPA

- approved air quality monitoring network, in accordance with 40 CFR part 58.

(4) Contingency measures : Th e same requirement continues to apply.

(5) Conformity determination: While EPA’s LMP option does not exempt an area from

the need to affirm conformity, the area may demonstrate conformity without submitting an emissions budget. Under the LMP option, the emis sions budget s are essentially not constraining for the leng t h of the maintenance period , because it is unreasonable to expect

t hat the qualifying area will experience so much growth in that period that a violation of the CO NAAQS would result. For this reason, any Federal actions requiring conformity determinations under the transportation conformity rule s could be considered to satisfy the
“bu dget test,” required in 40 CFR 93.158(a)(5)(i)(A), 93.118, 93.119, and 93.120

. While not subject to the budget test, the limited maintenance areas remain subject to other transportation conformity requirements of 40 CFR part 93, subpart A.7

IV . STATE SUBMITTAL

O n July 18, 2011

, PADEP submitted, on behalf of ACHD

, a SIP revision

, that was supplemented on November 26, 2013 . The SIP revision consist s of the second 10

- year update to the CO NAAQS maintenance plan for the Pittsburgh Area , a s required by CAA section 175A(b). The July 18, 2011 submission included a maintenance demonstration

, a verification of continued

attainment

, and a contingency plan

. The November 26, 2013 supplemental SIP revision included

the attainment emissions invent ory and clarified the July 18, 2011 submittal’s maintenance

demonstration

.

V . EPA’S EVALUATION

This section present s a detailed discussion of EPA’s evaluation of the Pittsburgh Area ’s CO

second maintenance plan provided on the July 18, 2011 and Novembe r 26, 2013 submittals.

A. LMP Eligibility

The last violation of the 8

- hour CO NAAQS in the Pittsburgh Area was in 1987. The second highest non

- overlapping 8

- hour CO average concentration level (“second highest 8

- hour average) is used for comparison to the 8

- hour CO NAAQS. Table 1 shows the historic CO 8

- hour design values (i.e., the second highest 8

- hour average CO levels ) for the CO monitoring sites in the Area

over the 1988

- 20 13 period, as recorded in EPA’s Air Quality System (AQS) and included in th e submittal

. See Appendixes A

- 1 thru A

- 4 of this document for the AQS Reports (AMP450NC)

with 2010

- 2013 air quality data

.

Monitoring data shows that the Pittsburgh Area continues to attain the CO NAAQS. As shown in Table 1, t he second highest 8

- hour C O average concentrations recorded at all monitoring

stat ions in the Pittsburgh Area have remained below 7.65 ppm since 1994. In addition, ACHD reported that the 1

- hour CO NAAQS has not been violated in the Pittsburgh Area since 1980,

and has been below 15 ppm since 1988. Thus, monitoring data show that Pittsburgh Area

continues to be eligible for the LMP option.8

Table 1

. Pittsburgh Area ’s CO Second Highest 8

- Hour Average Concentrations during

1988

- 2 0 13 , in ppm

Year Oakland a

( 42

- 003

- 0026) Forbes Av enue

at Grant Street (Courthouse) (42

- 003

- 0038) Gateway

Center Subway

Entrance (Point) b
( 42

- 003

- 0052 ) Flag Plaza

(Bedford Avenue) b
( 42

- 003

- 0031 )

1988 8.4 6.6 6.5

- 1989 6.5 7.8 6.7

- 1990 6.9 8.1 6.5

- 1991 5.0 6.2 6.6

- 1992 7.7 7.8 6.7

- 1993 4. 8 6.2 5.2

- 1994 5.6 7.5 6.8

- 1995 4.3 5.9 3.8

- 1996 5.0 4.8 3.9

- 1997 2.5 3.9 2.9

- 1998

- 4.9 3.1

- 1999

- 4.0 3.1

- 2000

- 3.5 2.6

- 2001

- 3.4

- - 2002

- 2.9

- - 2003

- 3.5

- 2.2

2004

- 2.5

- 1.9

2005

- 2.3

- 1.8

2006

- 2.1

- 1.8

2007

- 3.5

- 1.3

2008

- 1.6

- 1.3

2009

- 1.5

- 1.3

2010

- 1.7

- 1.2

2011

- 1.6

- 1.4

2012

- 1.7

- 1.5

2013 c 1.5 1.4

Source: Pennsylvania’s July 18, 2011 SIP submittal and EPA’s January 9

, 2014 AQS Reports AMP450

.

a The CO monitor at the Oakland sit e ( AQS ID: 42

- 003

- 0026) was terminated in October 1997, as approved by

EPA.

b EPA approved the removal of the CO monitor at the Gateway Center Subway Entrance (Point) ( AQS ID: 42

- 003

- 0052) in May 2000 and its relocation to the Flag Plaza ( AQS ID: 42

- 003

- 0 031) near the Civic Arena, which started operating in 2003.

c Air quality monitoring data for 2013 is preliminary.9

B

. Attainment Emissions Inventor y

F or the CO maintenance p lan, ACHD developed a 2008 a ttainment emis sions inventory to identify th e level of actual emissions in the Pittsburgh A rea that is suf ficient for the Area to
continue to attain the CO NAAQS. The Pittsburgh Area’s CO attainment inventory is based on the latest available planning assumptions for the 2008, reflecting typical win ter day CO

emissions for the Area

. ACHD selected the 2008 year for its attainment emissions inventory because it contained at the time of submittal the most current and comprehensive emissions estimates that were representative of actual emissions in Alle gheny County, and because during this time the air quality was showing maintenance of the CO NAAQS in the Area.

The 2008 emissions inventory was taken from EPA’s 2008 National Emissions Inventory (NEI) (Version 2, April 10, 2012) for the months of Januar y, February, and December, and was adjusted as necessary to reflect typical winter day CO emissions. The submitted 2008 attainment inventory contains emissions estimates of point, area, mobile onroad and mobile nonroad road

sources in the Area

. T he prima ry source of CO emissions in the Allegheny Area is the onroad (highway) sources , contributing to 5 4 % of total CO emissions of the Area. Table 2 provides a summary of the 2008 attainment inventory submitted with the maintenance plan. Table 2 presents the 2008 attainment inventory in annual CO emissions and CO emissions for a typical winter day. For a more detailed evaluation of the 2008 emissions inventory, see EPA’s Technical Support Document (TSD) dated February 4, 2014 for this rulemaking action, which is

available online at www.regulations.gov , Docket number EPA

- R03

- OAR

- 2012

- 0248.

Table 2. Pittsburgh Area’s CO 2008 Attainment Emissions Inventory (tons per day)

Source Category CO Annual Emissions CO Typical Win ter Day Emissions

Point 25.28 22.76

Area 43.12 57.65

Onroad 265.48 396.38

Nonroad 155.11 96.99

TOTAL 488.99 573.78

C

. Maintenance Demonstration

U nder the LMP option, there is no requirement to project emissions over the 10

- year maintenance per iod for the Pittsburgh Area, as long as the Area continues to have a CO air quality at or below 7.65 ppm

. The monitoring data presented in Table 1 show that the Pittsburgh

Area has historically measured and continues to measure concentrations below 7.65 p pm. The

continuous downward trend in CO monitoring data in the Area has demonstrated that air quality improvements can be attributed to permanent, enforceable reductions of CO emissions

. These reductions are largely achieved through more stringent Federa l controls on vehicles and fuels,

and state and local measures implemented in the Area and approved in the Pennsylvania SIP

. In addition, EPA acknowledges that Allegheny County has a SIP

- approved PSD permitting progra m10

(78 FR 13493, February 18, 2013 ), wh ich prevents increas e of CO emissions from construction or modification of major stationary sources. EPA believes that t he LMP eligibility together with the continuation of existing CO emissions control programs, sufficiently and a dequately

demonstrate t hat the Pittsburgh Area will maintain the CO NAAQS through the second 10

- year maintenance period and beyond.

Although not required, ACHD included a demonstration as part of its second maintenance plan to show maintenance of the CO NAAQS during the secon d 10

- year period for the Pittsburgh

Area. For a maintenance demonstration, emissions inventories are required to be projected to future dates to assess the influence of future growth and controls; however, the demonstration need not be based on modeling. See Wall v. EPA, supra; Sierra Club v. EPA, supra. See also 66

FR 53099

- 53100 and 68 FR 25430

- 32. ACHD use d project ed inventories to show that the Pittsburgh Area continues to remain in attainment and developed project ed inventories for an interim year of 201 3 and a maintenance end year of 202 2. Where the emissions inventory method of showing maintenance of the NAAQS is used, a state may demonstrate maintenance by showing that the future emissions of a pollutant or its precursors will not exceed the lev el of the attainment inventory. The demonstration should project emissions for a period of 10 years following the redesignation or the initial 10

- year maintenance period. The projected inventory should consider future growth, should be consistent with th e attainment inventory, and should document data inputs and assumptions.

Evaluation of Projected Emissions Inventories

The projected 2013 and 2022 emissions inventories include typical winter day CO emissions estimates only for the onroad sources in th e Pittsburgh Area. As mentioned earlier, this sector constitutes the primary emissions source category in the Pittsburgh Area and emissions reductions from this source category should be sufficient to demonstrate maintenance of the CO NAAQS for the Area. EPA has evaluated the accuracy of the projected emissions inventories based on the thorough review of the methodology and data assumptions used by ACHD for modeling the CO emissions in the Allegheny County.

The 2013 and 2022 onroad emissions inventorie s were developed with EPA’s latest highway

emissions model at the time of submittal , MOVES2010a. 1 When using MOVES2010a for developing SIP inventories, the methodologies used should conform to the recommendations provided by EPA in the “Technical Guidance on the Use of MOVES2010a for Emission Inventory Prepara tion in State Implementation Plans and Transportation Conformity .” ACHD used a pre

- and post

- processing software, PPSUITE, to assist in processing traffic data and VMT

1 MOVES2010 is a computer model designed by EPA to estimate air pollution emissions an d emissions inventories of various pollutants and precursors from on

- road mobile sources for SIP and transportation conformity purposes. MOVES2010 was designed to replace the previous emissions model, MOBILE6.2, which was released in 2004 (69 FR 28830). MOVES2010 was released o n March 2, 2010 (75 FR 9411), while MOVES2010a, a minor revision to enhance model performance, was released subsequently on September 8, 2010. ACHD used MOVES 2010a in developing the projected emissions inventories.11

and the results produced by M OVES2010a . ACHD also used CENTRAL software system as the process controller to assist running MOVES2010a

.

ACHD used a combination of local data and national default data (internal to MOVES2010a) to estimate CO emissions for a typical winter day during 2013 and 2022. As recommended by EPA’s guidance, ACHD used local data for primary modeling input parameters which have a significant impact in mobile source emissions, including: Temperature, humidity, gasoline fuel formulations, vehicle source type popu lation and age distribution based on vehicle registration data from the Pennsylvania Department of Transportation (PennDOT), Department of Motor Vehicles (DMV), traffic volumes and VMT estimates from PennDOT Roadway Management System, and inspection and ma intenance (I/M) parameters. Most local data inputs reflect the latest planning assumptions based on 2008 data, with the e xception of I/ M programs and fuel

characteristics inputs which are based on the most current assumptions.

To develop the 2013 and 2 022 traffic parameters as input data for MOVES2010a, ACHD used growth rates based on 2008 local traffic data and socioeconomic forecasts developed following the methodology from the 2005 PennDOT’s Final Report “Statistical Evaluation of Projected

Traffic G rowth, Traffic Growth Forecasting System” (March 14, 2005). Daily and monthly seasonal factors, developed from PennDOT’s Bureau of Planning and Research “2008 Pennsylvania Traffic Data,” were used to adjust traffic data to a typical winter day. The proje cted inventories take into account control measures which were in place in 2008 and are expected to be in place by 2022 for Allegheny County. These vehicle control measures include: The National Low Emission Vehicle Program (NLEV) and Federal Tier II Low Sulfur Program, emissions standards for medium and heavy duty vehicles in 2002, 2004, 2007, and 2011, Stage II and Onboard Refueling Vapor Recovert (ORVR), and the Pennsylvania Clean Vehicles (PCV) Program (PaCode, Title 25, Chapter 126) that incorporates the California Low Emission Vehicle Program (CA LEVII).

EPA finds that the 2011 and 2013 emissions inventories were developed in conformance with EPA’s guidance, and therefore, are approvable as part of the maintenance demonstration. A summary of the projected onroad CO emissions inventories for the Pittsburgh Area is provided in

Table 3.

Table 3. Pittsburgh Area’s CO Projected 2013 and 2022 Vehicle Miles Traveled (VMT)

and Typical Winter Day Emissions for Onroad Sources, in tons per day ( tpd )

201 3 2022

VMT CO Typical

Winter Day

Emissions VMT CO Typical Winter Day

Emissions
25,727,530 394.53 28,377,731 336.27

Evaluation of Maintenance Demonstration12

The purpose of the maintenance demonstration is t o show that future CO emissions will remain

at or below the 2008 attainment emissions levels for the Pittsburgh Area through the 202 2.

Table s 4 provide s a comparison of the CO emissions inventories for the Pittsburgh Area for the 2008 attainment year, the 2013 interim year, and the 2022 maintenance plan end year. Despite of the projected increase in VMT (see T able 3) in the Area, t he inventories show that the CO

emissions between 2008 and 2022 for the Area are projected to be reduce d by 15 perc ent , due to the implementation of the vehicle control m easures in Allegheny County

. EPA finds that

maintenance demonstration show s that the Pittsburgh Area will continue to maintain the CO NAAQS during the second maintenance period , throughout 2022

.

Table 3. Comparison of the 2008, 2013
, and 2022 CO Typi cal Winter Day Emissions for

Onroad Sources in the Pittsburgh Area, in tp d

Emissions of On r oad Sources Emissions Reductions

2008 2013 2022 2008

- 2013 2008

- 2022

396.38 394.53 336.27 1.85 60.11

D . Monitoring Network and Verification of Continued Attai nment

I n accordance with 40 CFR part 58, ACH D operates and maintains a n EPA

- approved CO monitoring network in the Pittsburgh Area

, in order to ve rify attainment of the CO NAAQS and ensure the need to trigger contingency measures. Currently, the monitorin g network consists of 2 monitoring sites

, the Forbes Avenue and Grant Street site ( AQS ID: 42

- 003

- 0038) and the Flag Plaza site ( AQS ID: 42

- 003

- 0031 ), whose data is eligible for comparison to the CO NAAQS. ACHD operated a CO monitoring site in Oakland ( 42

- 003

- 0026 ) until its termination on October 1997. The monitor at the Gateway Center Subway Entrance (42

- 003

- 0052) was shut down in May 2000 to accommodate local construction work and, as approved by EPA, was permanently relocated to the Flag Plaza site (4 2

- 003

- 0031) in 2003.

EPA previously determined that the CO monitoring network for the P ittsburg h Area is adequate

. EPA found that the number of monitors in the Area meets the minimum regulatory requirements given in 40 CFR part 58 , appendix D, section 4. 2 , and that the monitoring network in place is in

accordance with ACHD’s most recent annual monitoring network plan s approved by EPA, as required by 40 CFR 58.10. ACHD’s 2013 annual ambient monitoring network plan was approved by EPA in a December 10, 2 013 letter from Shawn M. Garvin, Regional Administrator

of EPA Region III, to James Thompson, Air Quality Program Manager of ACHD

. In addition,

ACHD has committed to continue maintain ing a CO monitoring network in a ccordance with EPA requirements. EPA be lieves ACHD ’ s current CO monitoring network is adequate to verify continued attainment of the CO NAAQS in the Pittsburgh Area.13

E . Contingency Plan

The Pittsburgh Area’s s econd CO m aintenance p lan carries forward the same contingency provisions that were included in the first maintenance plan and previously approved by EPA.

The plan relies on quality

- assured air quality monitoring data in the Pittsburgh Area to identify

the triggering indicator necessary to implement contingency measures. As a trig gering event, a

verified ambient CO concentration for an 8

- hour period over the 8

- hour CO NAAQS, or 9.00 ppm, must be recorded at least twice at one monitor station from November to February. In the

event of a violation of the 8

- hour CO NAAQS, a “vehicle idling restriction” will be implemented as a contingency measure . The vehicle idling restriction is applicable from November to February throughout the Allegheny County and consists of limiting t o five minutes t he amount of time that a gasoline engine veh icle is permitted to idle

. This restriction will have the following exceptions : T he need for heating and powering of refrigeration systems on trucks, operation of

emergency vehicles and vehicles that are motionless due to traffic conditions beyond operat or’s

control. Three (3) months after ACHD record s a violation or once EPA notifies ACHD that this contingency measure must be implemented

, ACHD will adopt within 12 months t he vehicle idling restriction as a regulation . The regulation will be implemented within 8 months after adoption. In the future, A CHD may request EPA to consider the approval of a lternative contingency measures by providing a demonstrat ion that the alternative measure s will provide an air quality and public health benefit equal to or greater than that resulting from the implementa tion of the idling restriction.

F

. Transportation Conformity

While EPA’s LMP option does not exempt the Pittsburgh Area from the need to affirm conformity, under this option the Area may demonstrate transp ortation conformity without submitting MVEBs

. ACHD did not submit any MVEBs with the Pittsburgh Area’s CO second maintenance plan

. However, EPA believes that the second maintenance plan demonstrates that it is unreasonable to expect that the Area would e xperience enough growth in motor vehicle (onroad) emissions for a violation of the CO NAAQS to occur, and on that basis, EPA is proposing to approve this plan for transportation conformity purposes.

Evaluation of transportation conformity for transporta tion projects in Allegheny County is usually performed by the Southwestern Pennsylvania Commission and other agencies. This determination waives the need for CO MVEB, although it does not relieve the Pittsburgh Area of the other transportation conformity requirements. After EPA’s approval of this finding , there will be no requirement for ACHD to satisfy the regional emissions analysis with respect to CO under 40 CFR 93.118 and/or 40 CFR 93.119 in determining the conformity of transportation plans, program s and projects in the Pittsburgh Area. See 40 CFR 93.109(j).14

V I

. RECOMMENDED AGENCY ACTION

EPA finds that t he second CO maintenance plan for the Pittsburgh Area, submitted by the

Commonwealth as a SIP revision on July 18, 2011 and supplemented on Nov ember 26, 2013

, provides an acceptable update of the various elements o f the initial EPA

- approved CO maintenance plan , and essentially carries forward all of the control measures and contingency provisions relied upon in the earlier plan

. EPA concludes th at the Pittsburgh Area’s second CO maintenance plan concurs with EPA’s guidance for limited maintenance plans and thus, satisfies

the requirements of CAA section 175A

.