Draft: June 28, 2006

1 Summary of Stakeholder Comments on the Contribution Assessment

June 28, 2006

The MANE-VU Contribution Assessment was posted for external review on the MANEVU website and stakeholders were invited to comment from May 16 th to June 16 th

. Twelve stakeholders commented on the template and t heir comments are summarized

here.

Conceptual Model of RH (Chapter 2)

It was noted that the text on page 2-6 stated that “coal combustion is often a source of significant amounts of organic carbon.” This statem ent was attributed to a draft EPA report prepared in 2003. Earlier this year John Bac hmann of the EPA stated publicly that

the EPA erred and this statement is incorrect.

It was noted that the report has a section discussi ng the revised IMPROVE equation but contains no conclusions regarding whether MANE-VU w ill adopt any of the revisions. The commenter urges the MANE-VU states to incorpora te the revisions to the IMPROVE equation that have been recommended by the EPA convened IMPROVE Committee because the method by which the natural b ackground goal is calculated will have a dramatic effect on those sources and any con trols implemented by the MANE-VU states should be supported by the most recent scien ce available.

It was once again noted that the report is inconclu sive about whether or not the revised IMPROVE equation will be adopted. The commenter not ed that an EPA endorsed

IMPROVE Committee was convened and revised the IMPR OVE equation. Thus, the commenter urges MANE-VU to incorporate these revisi ons into its calculations and assessments. The method by which the natural backgr ound level and reasonable progress goals are calculated significantly impact the level of reductions that will be needed to demonstrate reasonable progress and these calculati on methods should be supported by

the best scientific data and information available.

It was noted by a commenter that the natural and ba seline visibility values associated with the Forest Service sites, Great Gulf and Lye B rook, appear to be reasonable. However, the commenter is asking a Forest Service v isibility analyst to look at the

numbers also since he works with all the IMPROVE si tes across the country. The

commenter will make the information known as soon a s the information is received from the analyst.

Overview of Modeling Results (Chapter 3)

It was noted that in Section 3.1.1, Figure 3-1 and Figure 3-2, 20% Worst Extinction plots (right side plots) all look the same for all Class I areas, the Acadia plot appears to be ok, but the other Class I area plots need to be correct edDraft: June 28, 2006

2

It was noted that the values for particle extinctio n in Table 3-2 and those reported as old algorithm data in Table 3-7 should match but some o f the values are inconsistent.

It was stated that some of Table 3-4 is not quite c orrect, because the way that the f(RH) values were developed and applied requires the assu mption that concentrations of all components of the aerosol will be rolled back by th e same percentage. Therefore, the

values in the last two columns should be considered approximations. The same applies to

the last four columns of Table 3-5. As for Table 3- 6 (described in footnote 13, where Table 3-4, should be Table 3-9), the method used is arbitrary, but not unreasonable and the values in Table 3-6 should be viewed as rough a pproximations.

Why did the extinctions due to EC, soil, and course matter change in Tables 3-7 and 3-8? The formulas for calculating extinction due to thos e components did not change from the old to the new algorithm.

Data Analysis (Chapter 5)

It was noted that the analysis focuses exclusively on sulfates, except the emissions inventory discussion in Section 4.1 and Appendix B. This information on non-sulfate components is not considered in any of the analyses except for the CMAQ and REMSAD modeling and results for non-sulfate components are not presented in this report. The reason for the sulfate focus is made clear early in the report, however, this focus is not

universal.

A commenter inquired in regards to the trajectory a nalyses in Section 5.1, if had MANEVU done any analysis for trajectories at other than 500m in elevation (as noted on page 5- 2) since trajectories for 200m and 1000m were creat ed? In the BRAVO study, trajectory at one level went in totally the opposite direction from one at a different level, so that trajectory analysis had to consider several levels to achieve any confidence in their results or to indicate their levels of uncertainty. That su ch altitude-related biases can occur is seen in the statement at the top of page 5-8, where HYSPLIT and ATAD trajectories disagree.

It was noted that in section 5.1 Trajectory Analysi s, the first paragraph is confusing: It states that back trajectories were calculated for t he five year period 1998-2002 yet the last sentence states that this analysis used back trajec tories calculated from the baseline period 2000-2004. ME DEP suggests adding a paragrap h about the 1998-2002 analysis (if that was done) and rewriting the first paragrap h in this section. The paragraph changes are quite specific, please see the first page of th is specific comment for the changes.

At the bottom of page 5-5 what is the “large sulfat e” source, since emissions of primary

sulfate are small?

Is the text on page 5-6 trying to say that Figure 5 -5 applies only to large sources and not

to all sources combined?Draft: June 28, 2006

3

Chemical Transport Models (Chapter 6)

It was stated that the report focuses mostly on tod ay’s situation and does not give much insight into how its conclusions would change after current regulations, including CAIR are fully implemented. The future projections are c learly part of the analysis since they were included in CMAQ modeling for 2009 and 2018. T he report also gives little insight into what assumptions were made to arrive at the 20 09 and 2018 emissions.

The commenter noted that in future decisions regard ing strategies to demonstrate uniform rates of progress the implementation of regulations such as CAIR or state specific requirements that will attain reductions in additio n to CAIR (such as Massachusetts’ 310

CMR 7.26 rules for SO 2 and NO

x ) will yield significant improvements in visibility over the next decade. It is clear that Brigantine in New Jersey will meet their uniform progress goals by 2018. However, it is not clear from the de scription of emission inventories used in the modeling analyses what specific on-the-books (OTB) or on-the-way (OTW)

reductions were assumed in the 2009 and 2018 invent ories. It was suggested that MANEVU provide this information and make every effort t o account for all emissions reductions expected to be achieved during the initi al rate of progress determination period (through 2018) in refined modeling efforts to asses s reasonable progress goals.

It was also noted that the use of 2002 emissions (2 002 emissions for EGUs and 1999 emissions for all other source sector) is appropria te for assessment of contribution to the baseline (2002-2004) period under the haze rule. Bu t this approach does not account for emissions reductions under CAIR (Clean Air Intersta te Rule) and other state and federal regulatory requirements. To identify further emissi ons reductions needed to achieve reasonable progress in 2018, it is essential to con sider the progress made due to emissions

reductions between 2002-2018. The relative source c ontributions will be different in 2018 than in 2002 as emissions reductions will be spatia lly uniform. It is recommend that MANE-VU also consider techniques to evaluate source contribution in 2018 as part of the reasonable progress analyses.

It was noted that the authors of the report declare d in several places that their results are accurate, without proving this claim. For example o n page 6-2, the use of GEOS-CHEM inputs to boundary conditions is supposed to be to “ensure accurate representation of the general trends and sulfate patterns.” As anyone who has worked with the current generation of chemical models knows, this is hyperb ole, according to the commenter.

Lagrangian Dispersion Models (Chapter 7)

In Section 7, Lagrangian Dispersion Models and Appe ndix D both need reference

subsections

It was noted by a commenter that CALPUFF model appl ications are problematic for sources at transport distances greater than 200-300 km from the receptor. According to the EPA and IWAQM (Interagency Workgroup on Air Qua lity Models), CALPUFF should only be used to evaluate sources within 200- 300 km of the receptor because atDraft: June 28, 2006

4

greater distances CALPUFF underestimates the horizo ntal extent of dispersion and overestimates sulfate concentrations at the recepto rs. Thus contributions from VISTAS states to Class I areas in New England are most lik ely overestimated. This concern is

discussed in more detail in the VISTAS comment.

The use of CALPUFF to model transport distances ove r 1,000 km is stretching the capacity of the model. The rationale behind using C ALPUFF for such long distances is

weak and enhancements to CALPUFF have reduced its o verestimation tendencies, but only if these enhancements are turned on and used w ith expert judgment. The MANE-VU

discussion does not indicate whether features such as puff-splitting were applied and

what criteria were used to determine when to use th em. The fact that the BART rule required modeling protocols for distances over 200 km does not imply an endorsement of

the use of the model at such distances and in reali ty the application of CALPUFF at distances exceeding 300 km is very questionable.

Another commenter also noted that a significant por tion of the contribution assessment was completed using air quality models such as CALP UFF, which are not suited for SIP quality regional air modeling. The commeter urges M ANE-VU states to complete a more rigorous modeling exercise using either CMAQ or CAM

x to support its final contribution

assessment.

A commenter noted that in Table 7-1 the faults of C ALPUFF are demonstrated. The modeling with observation-based meteorology alone t ended to underestimate ambient sulfate concentrations by nearly a factor of 2 at C lass I areas in the southern part of the MANE-VU domain. The application with MM5 meteorolog y did better. However, as the final comparison of attribution rankings (Figure 8- 1 in the report) shows, the ranking was not particularly sensitive to modeling biases.

It was noted, once again, that with the emissions a nd meteorological inputs in question the CALPUFF (MD) analysis should not be used at thi s time for Maine’s Class I areas

Synthesis of Results Using Different Source Assessm ent Techniques (Chapter 8)

Note that the first line of Section 8.1 points out that the Q/D and emissions times residence time approaches (numbers 1 and 2 in the l ist at the beginning of VISTAS Comments on the MANE-VU Contribution Analysis Repor t) are “crude methods.”

It appears that Acadia and Moosehorn have the highe st percentage of “out of domain” area contribution while they are also closest to th e grid boundary. The commenter requested MANE-VU’s best-informed explanation on wh ere this significantly large percentage is coming from.

The commenter mentioned that perhaps there is more information related to the REMSAD modeling results if this information is brok en down by tagged boundary conditions in group 3 of the REMSAD model run that could be provided.Draft: June 28, 2006

5

It was noted that the modeling analyses indicated t hat Canadian emissions contribute significantly to observed sulfate and visibility im pairment in Class I areas. There is some level of uncertainty with respect to the current in ventory of Canadian emissions, transboundary influences appear to be very pronounced an d the states should account for this non-domestic component when calculating reasonable progress goals so that domestic sources are not disproportionately burdened with re ductions to meet goals that are affected by non-domestic sources. It is suggested t hat sources in the MANE-VU region should not be required to further reduce emissions to account for or to offset transboundary contributions.

Conclusion (Chapter 9)

It was noted that initially the document stated tha t much of the modeling analyses and results were preliminary and provide a “first step” toward identifying sources of visibility impairment in the MANE-VU region, however, Chapter 9 states that “...MANE-VU findings are sufficiently robust to serve as a basi s for inter-RPO consultations in the regional haze planning process.” The commenter agre es that RPOs should continue discussions but they caution MANE-VU’s conclusion r egarding impacts of modeling refinements and these preliminary assessments in no way should preclude MANE-VU from completing a more rigorous modeling exercise u sing more refined modeling techniques such as CMAQ or CAM

x in addition to updated inventories to support its final

contribution assessment.

Appendices

It was noted that the last sentence of the first pa ragraph on page C-2 contains a dated

inaccurate assessment of current Ozone and PM 2.5 NAAQS violation trends in the Northeast US region. The suggested rewrite is very specific, please see the second page of comments from MD DEP for the suggested changes.

The commenter agrees with the decision on page C-30 of Appendix C to switch to CMAQ V4.5 modeling for the final Regional Haze mode ling analysis primarily because a

sea salt calculation scheme was added and sea salt is a significant factor in regional haze at coastal Class I areas in the MANE-VU region

The final changes suggested are minor (format, spel ling, grammar and reference, footnote and figure numbering) edits and comments, which are very specific, please see the third page of comments from the MD DEP for the suggested changes.