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Department of Natural Resources and Environmental Control
Division of Air and Waste Management
Statutory Authority: 7 Delaware Code, Section 901(b) and 903(e)(2)a (7 Del.C. §901(b) §903(e)(2)a)
7 DE Admin. Code 3553
 
PROPOSED
 
REGISTER NOTICE
SAN # 2011-16
 
1. TITLE OF THE REGULATIONS:
Proposed Amendment to the April, 2008 Delaware State Implementation Plan For Attainment of the PM2.5 Annual National Ambient Air Quality Standard
 
2. BRIEF SYNOPSIS OF THE SUBJECT, SUBSTANCE AND ISSUES:
On March 2, 2010 the USEPA published a notice in the Federal Register of the approval of using the Motor Vehicle Emissions Simulator (MOVES) model as a tool for calculating on-road mobile emissions. The agency also stated in the notice that “today's approval also starts a two-year transportation conformity grace period which ends on March 2, 2012, after which MOVES 2010 is required to be used for new regional emissions analyses for transportation conformity”. In consideration of the MOVES requirement for regional emissions analysis and that the MOVES model predicts more accurate mobile emissions; the Department is proposing to amend its currently adopted State Implementation Plan with a revised on-road mobile emissions budget using the MOVES model. This action will more accurately calculate the on-road sector’s portion of particulate matter and oxides of nitrogen emissions in New Castle County. The action will also address the compatibility issue with future regional emissions analyses for transportation conformity for the annual PM 2.5 standard.
 
3. POSSIBLE TERMS OF THE AGENCY ACTION:
This action is not a regulation and does not have a sunset date.
 
4. STATUTORY BASIS OR LEGAL AUTHORITY TO ACT:
7 Del. C., Chapter 60, Environmental Control
 
5. OTHER REGULATIONS THAT MAY BE AFFECTED BY THE PROPOSAL:
None
 
6. NOTICE OF PUBLIC COMMENT:
Statements and testimony may be presented either orally or in writing at a public hearing to be held on December, 28, 2011 beginning at 6:00 PM in the DNREC Auditorium, located at the Richardson & Robbins Building, 89 Kings Highway, Dover, DE 19901. Interested parties may submit comments in writing to: Philip Wheeler, DNREC Division of Air Quality, 655 South Bay Road, Dover Delaware, 19901.
 
7. PREPARED BY:
Philip Wheeler (302) 739-9402 November 8, 2011
Email address: philip.wheeler@state.de.us
 
Proposed Revision to Delaware’s 2008 State Implementation Plan For Attainment of the PM2.5 Annual National Ambient Air Quality Standard - Attainment Demonstration
 
October 2011
 
Section 1. Introduction
In April, 2008 Delaware submitted to the EPA its “State Implementation Plan for Attainment of the PM2.5 Annual National Ambient Air Quality Standard - Attainment Demonstration” (the “2008 PM2.5 SIP”).1 The 2008 PM2.5 SIP set out to accomplish four primary goals:
Treat emission reduction credits (ERCs) banked under 7 DE Admin. Code 1134, Emissions Banking and Trading Program, as “emitted.” As such, the future use of these credits is consistent with, and will not interfere with any calculation or provision of this SIP.
This SIP revision is related to the PM2.5 and NOx on-road mobile source budgets that were established in the 2008 PM2.5 SIP. Those SIP budgets were established using EPA’s MOBILE6.2 model.2 However, effective March 2012 3 a new on-road mobile emissions model – Motor Vehicle Emissions Simulator (MOVES) – is required to be used in all planning and transportation conformity determinations.
The purpose of this SIP revision is to 1) replace the on-road mobile emissions budget in the 2008 PM2.5 SIP with a budget that is based on the MOVES model, 2) demonstrate that the MOVES based mobile source budget is consistent with attainment of the PM2.5 NAAQS by 2010, and 3) demonstrate that the contingency requirements of the Clean Air Act (CAA) are met. No other changes or revisions to the 2008 PM2.5 SIP are proposed.
Note that this SIP revision impacts only PM2.5 and NOx emissions and calculations. While sulfur dioxide (SO2) is a pollutant of concern relative to PM2.5 it is not a pollutant of concern for mobile budgets, and therefore no SO2 changes are proposed as part of this SIP revision. The treatment of SO2 emissions in the 2008 PM2.5 SIP is unchanged.
Questions or comments regarding this SIP revision should be addressed to Phil Wheeler, M.S. Project Leader for Transportation Conformity, Planning Branch, Division of Air Quality, Delaware Department of Natural Resources and Environmental Control, at philip.wheeler@state.de.us.
 
Section 2. Revised On-Road Mobile Source Budgets
This SIP revision establishes on-road mobile emissions budget for New Castle County for PM2.5 and NOx. When approved by the EPA, all subsequent PM2.5 conformity analyses will test future on-road mobile emissions calculated for transportation plans in New Castle County with this new budget.
2.1 EPA’s MOVES model was used to quantify PM2.5 and NOx emission from on-road mobile sources. These emissions are shown in Table 2-1 below. The associated 2012 MOVES input and output files are included in Appendix A of this SIP revision.
Table 2-1 On-Road Mobile Emission Budget (Tons per Year (tpy))
 
PM2.5
 
2.2 This SIP revision establishes the emission levels identified in Table 2-1 as the on-road mobile emissions budget for New Castle County for PM2.5 and NOx.
 
Section 3. Demonstration that 2009 MOVES based On-Road Mobile Source Emissions are Consistent with Attainment of the PM2.5 NAAQS by 2010
Delaware demonstrated attainment of the annual PM2.5 NAAQS in its 2008 PM2.5 SIP by showing that Projected 2009 Emissions (i.e., the 2009 emission levels after the implementation of all state and federal control requirements) were less than the Attainment Targets (i.e., the emission levels needed for attainment based on modeling). This same methodology is used below to demonstrate that the MOVES based mobile budgets presented in Section 2 above are consistent with attainment of the PM2.5 NAAQS.
3.1 Community Multi-scale Air Quality Model (CMAQ) modeling was conducted in the 2008 PM2.5 SIP to demonstrate that Delaware and the entire Philadelphia based non-attainment area would attain the PM2.5 NAAQS in 2010 4. CMAQ modeling demonstrated that the Delaware emission levels shown in Table 3-1 are the levels that are necessary for, and consistent with attainment of the annual PM2.5 NAAQS. These emission levels reflect the level of emissions needed for attainment, and are therefore referred to as the “2009 Attainment Target.5, 6
 
Table 3-1 2009 Attainment Target (tpy)
PM2.5
3.2 Attainment year (i.e., 2009) emission levels were projected in the 2008 PM2.5 SIP based on final and enforceable State and Federal emission control requirements.7 These projected 2009 emission levels, which are referred to as the “Delaware Projected 2009 Emissions,” are shown in Table 3-2.
 
Table 3-2 Delaware Projected 2009 Emissions (tpy)
PM2.5
3.3 Table 3-3 compares the 2009 mobile emissions calculated using MOBILE6 and MOVES. The associated 2009 MOBILE6 and MOVES input and output files are included in Appendix B of this SIP revision.
 
Table 3-3 2009 MOBILE6, MOVES and Increase due to MOVES (tpy)
MOVES Increase
PM2.5
PM2.5
PM2.5
3.4 Adding the “MOVES Increase” emissions from Table 3-3 to the “Delaware Projected 2009 Emissions” from Table 3-2 yields a projected Delaware 2009 Emission level that reflects the use of the MOVES model instead of the MOBILE6 model. This revised emissions projection is shown in Table 3-4, and is referred to as the “Revised Delaware Projected 2009 Emissions.”
 
Table 3-4 Revised Delaware Projected 2009 Emissions (tpy)
PM2.5
3.5 The “Revised Delaware Projected 2009 Emissions” (i.e., Table 3-4) are demonstrated to be consistent with attainment if they are equal to or lower than the “2009 Attainment Target” (i.e., Table 3-1). The “Revised Delaware Projected 2009 emissions” are compared to the “Attainment Target” in Table 3-5 below.
 
Table 3-5 Shortfall and Surplus by County and Statewide (tpy)
PM2.5
PM2.5
 
This comparison shows that there is a 64 tpy PM2.5 surplus in New Castle County, and a 2,303 tpy NOx shortfall for New Castle County. This demonstrates that, relative to direct PM2.5, the MOVES based mobile budgets are consistent with attainment. These results also indicate that NOx requires further analysis.
3.6 Because of the regional nature of secondarily-formed sulfate and nitrate, and the broad modeling domain of the CMAQ modeling, which included all of Delaware, emission reductions from Kent and Sussex counties will contribute to attainment within New Castle County and the Philadelphia based non-attainment area. Kent and Sussex counties are within the State of Delaware, contiguous to New Castle County, and are less than 200 kilometers away. EPA’s PM2.5 Implementation Rule specifically provides for the consideration of in-state NOX and SO2 reductions in their SIPs from sources up to 200 kilometers away from the non-attainment area boundaries.8
Consistent with this EPA rule, emissions from Kent and Sussex Counties were analyzed. Using the same methodology as above, statewide emissions are calculated and presented in Table 3-5. These results indicate that while there is a 2009 NOx shortfall of 2,303 tpy in New Castle County, there is a statewide NOx surplus of 1,239 tpy. The analysis demonstrates that the 2009 MOVES based emission shown in Table 3-3 do not impair Delaware’s ability to meet its SIP emissions targets or meeting EPA’s National Ambient Air Quality Standards for particulate matter. 9
 
Section 4. Demonstration that the Contingency Measure Requirements of the CAA are Met
Contingency measures are additional control measures to be implemented in the event that an area fails to either meet “reasonable further progress” or attain the standards by its attainment date. The quantity of emission reductions needed to satisfy contingency requirements is an amount equal to one year’s worth of required reductions.
Delaware demonstrated that the contingency requirements of the CAA were met in Section 9 of its 2008 PM2.5 SIP by showing that the Delaware control measures have reduced NOx and primary PM2.5 by more than is necessary to attain compliance with the PM2.5 NAAQS. This same methodology is used below to demonstrate that the “Revised Delaware Projected 2009 Emissions” in Table 3-4 are low enough to satisfy contingency requirements.
4.1 Quantification of the contingency requirement is discussed in detail in Section 9.1 of the 2008 PM2.5 SIP. The contingency requirement for NOx and PM2.5 is presented in Table 9-3 of the 2008 PM2.5 SIP, and shown below in Table 4-1.
Table 4-1 Contingency Requirement (tpy)
PM2.5
 
4.2 Demonstration that contingency requirement is met is shown if the “Revised Delaware Projected 2009 Emissions” shown in Table 3-4 are lower than the “Attainment Target” shown in Table 3-1 by at least the amount of the amount of the contingency requirement shown in Table 4-1. Table 3-5 shows this calculation.
Table 3-5 shows that a 64 tpy reduction of PM2.5 emissions are above and beyond that necessary for attainment. Since 64 tpy is greater than the contingency requirement of 26 tpy PM2.5, the contingency requirement is demonstrated relative to the pollutant primary PM2.5. Table 3-5 also indicates that NOx requires further analysis.
4.3 Because of the regional nature of secondarily-formed sulfate and nitrate, and the broad modeling domain of the CMAQ modeling, which included all of Delaware, emission reductions from Kent and Sussex counties will contribute to attainment within New Castle County and the Philadelphia based non-attainment area. Kent and Sussex counties are within the State of Delaware, contiguous to New Castle County, and are less than 200 kilometers away. EPA’s PM2.5 Implementation Rule specifically provides for the consideration of in-state NOX and SO2 reductions in their SIPs from sources up to 200 kilometers away from the non-attainment area boundaries.
Consistent with this EPA rule, emissions from Kent and Sussex Counties were analyzed. Using the same methodology as above, statewide emissions are calculated and presented in Table 3-5. This indicates that while there is a 2009 NOx shortfall of 2,303 tpy in New Castle County, there is a statewide NOx surplus of 1,239 tpy. Since 1,239 tpy is greater than the contingency requirement of 1,100 tpy NOx, the contingency requirement is demonstrated as met relative to the pollutant NOx.
 
Section 5. Summary
The analysis in Section 3 and Section 4 above demonstrates that 2009 MOVES based emission levels in table 3-3 are consistent with attainment and the contingency requirements of the CAA. This SIP revision is anticipated to be approved by the EPA in 2012. Because the 2012 based mobile budgets established in Section 2 of this SIP revision are less than the 2009 MOVES based emission levels shown in Table 3-3, Section 3 and Section 4 above also demonstrate that mobile budgets established in Section 2 are consistent with attainment and contingency requirements of the CAA.
 
Appendix A. 2012 MOVES input and output files
Appendix B. 2009 MOVES and 2009 MOBILE6 Input and Output Files
Appendices A and B may be viewed by request to Philip Wheeler, Division of Air Quality during normal business hours at the Division’s office at 655 South Bay Road, Suite 5N, Dover, Delaware, Delaware, 19901. Appointments can be made by calling 302/739-9402.
They also can be viewed on the Division of Air Quality website at:
http://www.dnrec.delaware.gov/whs/awm/Info/Regs/Pages/AQMPlansRegs.aspx.
 
15 DE Reg. 742 (12/01/11) (Prop.)
 

1
http://www.awm.delaware.gov/Info/Regs/Documents/DE_PM25_SIP_AD_fnl.pdf

2
Details of the MOBILE6 budget calculations are included in Section 8.2 of the 2008 PM2.5 SIP.

3
EPA has proposed to extend this date by one year; to March 2013.

4
A detailed discussion of the CMAQ modeling and modeling results can be found in Section 6 of the 2008 PM2.5 SIP.

5
Although New Castle County is the only nonattainment county, emission levels of all three counties are used in the attainment demonstration. This is discussed in Sections 3 and 4 of this SIP revision.

6
A detailed discussion of the emission inventories associated with the Attainment Target can be found in Section 5 of the 2008 PM2.5 SIP.

7
A detailed discussion of Delaware’s projected 2009 emission levels can be found in Section 4 of the 2008 PM2.5 SIP.

8
PM2.5 Implementation Rule, April 25, 2007 (72 FR 20586 at 20636)

9
Note that this is similar to the approach used in the 2008 PM2.5 SIP to address SO2 emissions. See Section 5 (page 65) of the 2008 PM2.5 SIP.