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PM2.5 CONFORMITY DETERMINATION for Baltimore Beltway I-695: MD 140 to MD 702

ERRATA: MDE Comments (8/2/07)

Comment: 1. Mention should be made to the revised PM2.5 daily standard in this document as of current there is an actual pending standard of 35 ug/m3.

Response: The analysis that was performed is a Project-level (hot-spot) Conformity Determination; that is, the project is demonstrated to be consistent with the transportation-related elements of the state implementation plan (SIP). The current Non-attainment Designation and SIP is based on the 1997 24-hour standard of 65 ug/m3. Therefore, the project level conformity determination must use this standard. Although there is an approved 2006 24-hour standard of 35 ug/m3, as shown on the attached schedule from EPA, non-attainment areas will not be re-designated by EPA until November 2009 and a revised SIP is not due until April 2013. (It should be noted that the comparison monitor in Cockeysville is currently below the 35 ug/m3 daily standard).

Comment: 2. The argument that emissions while high in 2010 and lower later on isn't a good comparison as 2010 is the attainment year and emissions need to be closely monitored so we meet the PM2.5 NAAQS by 2010, not later.

Response: Firstly, the purpose of this report is to determine on a project-level basis if the project will "cause or contribute to a new violation of the PM2.5 NAAQS, or increase the frequency or severity of a violation" (page 11). The report analysis is a "hot-spot" (or local) analysis. The report shows that the number of diesel trucks in the vicinity of the Cockeysville Monitor does not significantly increase between 2005 and 2010 and the comparison monitor is currently below the NAAQS in 2005-2007. Although as shown in Table 1 of the report numerous portions of the I-695 from MD140 to MD702 have been already constructed, the probable next opening date of roadway improvements is 2010. The year 2010 was used as the analysis year because as demonstrated on page 13 of the report: "As clarified in the preamble to the July 1, 2004 revision to the transportation conformity rule (64 FR 40056), the conformity rule requires that project-level analyses consider the year of expected peak emissions from the project. For PM2.5, this is expected to be a near-term year, such as the first year of operation of the project, because emission rates from vehicles are predicted to decline between the opening year (2010) and the last year of the area's transportation plan (2030) due in part to improvements in tailpipe emissions and national vehicle emissions control programs."

Secondly, considering a regional PM2.5 analysis, the report states on page 7, "The 2004 Baltimore Regional Transportation Plan and the FY 2007-2011 Transportation Improvement Program have been determined to conform to the intent of the SIP. The US Department of Transportation made a Conformity Determination on the CLRP and the TIP on November 8, 2006, and thus there is a currently conforming transportation plan and TIP in accordance with 40 CFR 93.114. The current conformity determination is consistent with the final conformity rule found in 40 CFR Parts 51 and 93. The I-695: MD 140 to MD 702 project was included in the regional emissions analysis and there have been no significant changes in the project's design concept or scope, as used in the conformity analyses."

Comment 3. Yes, EPA has modeled PM2.5 attainment for the Baltimore Region but the states are not done modeling for our PM2.5 SIP....basing a determination on EPA's modeling needs to come with a big caveat.

Response: The Project-level Conformity Determination followed the procedure outlined in "PM2.5 and PM10 Hot-Spot Analyses in Project-level Transportation Conformity Determinations for the New PM2.5 and Existing PM10 National Ambient Air Quality Standards" (71 FR 12468)." This method is a qualitative analysis that compares the analysis location to "another location with similar characteristics". The reference to EPA data is to indicate future trends not a specific Conformity Determination.

Comment 4. The built and natural environment between 1991 and current certainly seems much different to me...there has been lots and lots of development near this roadway in the past 16 years.

Response: Actually, the majority of development adjacent the I-695 from MD 140 to MD702 occurred prior to the 1991 FONSI; from the late 1950's to the mid'1980's. The development since 1991 is consistent with the future development outlined in the 1991 FONSI and therefore, is consistent with the 1991 FONSI.

Comment 5. Page 10: "The study area will not be significantly influenced by the nonroad sources in the major metropolitan area of Baltimore, MD. In addition, there are several EPA programs in place or proposed that would tend to reduce current background PM2.5 levels from nonroad sources. These include Diesel Engine Retrofit Programs, the Clean Air Nonroad Diesel Emissions Rule, the Clear Skies Act, and the Interstate Air Quality Rule." This is not really correct, PM2.5 in the Baltimore NAA is indeed impacted by non-road sources. While only about 5% of the total PM2.5 inventory, NR sources make up 15% of the NOx inventory and over 30% of the VOC inventory which are both precursors to PM2.5. The Clear Skies Act and Interstate Air Quality Rule are not NR control programs and these terms are very outdated. These programs were replaced by the Clean Air Interstate Rule over 4 years ago.

Response: Although the NOx and VOC nonroad precusor emissions are of concern for the regional analysis, this is project-level hotspot analysis and as stated in the above referenced guidance and summarized on page 6 of the report : "EPA requires hotspot findings to be based on directly emitted PM2.5, since secondary [precusor] particles take several hours to form in the atmosphere giving emissions time to disperse beyond the immediate area of concern" for a localized analysis.

Also, the study area is the immediate vicinity of I-695. According to page 8, "Existing and future land use along the study portion of the I-695 corridor consists of a mixture of suburban-residential and employment-commercial." Therefore, nonroad emissions would not significantly affect the study area.

Comment: 6. Do the truck %ages in this report compare at all to the truck model results from the BMC transportation model?

Response: The truck percentages were provided by SHA for the roadways within the study area. The purpose of the study is a project-level "hot-spot" analysis. Therefore, truck percentages (resulting in the number of diesel trucks) particular to the study area are needed to determine if the project would result in any "hot spot" violations of the NAAQS. Using the region wide truck percentages in the BMC model would not provide an accurate comparison for the project level hotspot analysis.

ERRATA: BMC Comments (8/17/07)

On 8/16/07 5:16 PM, "Sara Tomlinson" <> wrote:
Here are some informal comments I'd like to make on the I-695 PM2.5 conformity determination.

Comment 1) The Baltimore Regional Transportation Board should be abbreviated at BRTB rather than BRTP.
Response: Will comply

Comment 2) The Direct PM2.5 numbers in Table 2 should be updated with numbers from the most recent approved conformity determination (the one that is referenced in footnote 3). The 2002 number is the same, but the 2010, 2020, and 2030 numbers are slightly different.
Response: Will comply

Comment 3) The second paragraph under Section E on the sentence starting "Therefore, construction emissions...." Add a "be" before and a "d" on the end of "include."
Response: Will comply

Comment 4) In Section E under Air Quality- Monitors, it states that there are 8 monitors in the Baltimore nonattainment area. The Baltimore nonattainment area includes Anne Arundel, Carroll, Harford, and Howard Counties, as well as Baltimore County and Baltimore City. I believe the entire area includes more than 8 monitors. If you are referring to just the Baltimore City-Baltimore County area only, that should be specified. Also, are there 8 PM2.5 monitors, or 8 total monitors?
Response: Revised text to indicate PM2.5 monitors in the Baltimore Region

Comment 5) Under Section E, Future Scenario, it says a "continued decline" is shown through 2030. Is it a continued decline if the number goes up between 2020 and 2030? I know you mention that as well, but maybe the word "continued" isn't accurate.
Response: Text revised to clarify an overall decline

Comment 6) Under footnote #8, change "will" to "with".
Response: Will comply


Sara Tomlinson
Environmental Planner
Baltimore Metropolitan Council
2700 Lighthouse Point East, Suite 310
Baltimore, MD 21224
P: 410-732-0500 x1035 <>

Updated: 7/6/2011
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