1 

### Law Office of Robert Ukeiley

507 Center Street ◦ Berea, Kentucky 40403 ◦ tel.859

- 986

- 5402 ◦ fax.866

- 618

- 1017

Robert Ukeiley rukeiley@igc.org



# VIA EMAIL

March 10 , 201 4

Jeff Hunt, EPA Region 10, Office of Air, Waste and Toxics (AWT

– 107), 1200 Sixth Avenue, Suite 900, Seattle, WA 98101

Email: R10

- Public_Comments@epa.gov

RE: Washington: Kent, Seattle, and Tacoma Second 10

- Year PM10 Limited

Maintenance Plan

Docket #: EPA

– R10

– OAR

– 2013

– 0713

Dear Mr. Hunt:

On behalf of the Sierra Club and its many thousands of members and supporters who are at risk of adverse impacts of exporting coal mined in the Powder River Basin (PRB) via ports on

the West Coast, we are writ ing to comment on the United States Environmental Protection Agency’s (EPA) proposal to approve a limited second 10

- year PM10 maintenance plan for Kent, Seattle and Tacoma (Maintenance Plan)

. EPA must disapprove the Maintenance Plan because, as explained below and as the picture below demonstrates , the Maintenance Plan fails to protect these areas from dramatic increases in PM10 caused by coal exports.2

T he Northwest is facing at least three new coal export facilities that would export coal

mined in the P owder R iver B asin (PRB) to Asia . Coal would be transported via rail to the ports and then ship ped abroad

. There are also existing coal trains traveling through Washington to Canadian ports which could see significant increases in train traffic

. Finally, trains carrying tar
sands and/or Bakken oil to refineries may also rapidly increase

. EPA did not address tar sands/oil causing increased locomotive traffic in the maintenance areas. Thus, it is imperative that the Maintenance Plan adequately address these increases in PM10 emissions to ensure the PM10 National Ambient Air Quality Standard (NAAQS) is maintained.

I. EXPORT TERMINALS

Washington State has eleven deep draft ports, including seven in Puget Sound, one on the Washington coast, and three on the lower Columbia River. Powder River Basin coal shipped on BNSF rail lines can access each port. Originally there were six potential coal terminals but due to strong public opposition only three proposals remain. The three remaining terminals include: Cherry Point/Bellingham, WA, Longview, WA, Port of Morrow,

OR . There are also rumors of an additional facili ty being built by County Coal Limited but EPA did not address this possibility . Additionally, there are three terminals in Canada which are planning on dramatically increasing their coal exports , and some U.S. coal travels by rail through Washington to reach these ports. See Ex. 1 at Slide 4.

A

. No rthwest Coal Export Proposals that would impact Kent, Seattle and

Tacoma 1

1. Cherry Point/Bellingham , WA: Gateway Pacific Terminal

The Gateway Pacific Terminal proposed by Peabody Coal and SSA Marine would export

at 52.5 million tons of coal per annum ( MTPA ) . Ex. 1 at Slide 4

. The EIS scoping process

concluded in early in 2013, and a draft EIS is expected in the next year or two.

2. Longview, WA: Millennium Bulk Terminals

In late February of 2012 Millennium Bulk Logistics

– in partnership with Arch Energy

and Ambre Energy

– filed an application with the Washington Department of Environmental Quality (DEQ) for a new coal export terminal at the existing bulk terminal site in Longview,

WA. . The project application estimated the total coal capacity for the terminal at 4 8 MTPA. Ex.

1 at Slide 4. Draft EIS scoping is currently underway for this project following a scoping period

in the fall of 2 013 that elicited over 210,000 public comments.

1 See Exhibit 2

.3 3. Canad ian Ports

There are several operating coal ex port facilities in Canada, some of whi ch are expanding

—

Westshore /Roberts Bank

, Ridley, Nept un e, and Port Metro Vancouver . Some capacity at these terminals is for coal from the PRB, much of which travels via Washington. Arch Coal announced that it had reached an agreement with Canadian Crown Corporation Ridley Terminals Inc. in Prince Rupert, British Columbia to export 2.5 million tons of PRB coal annually

. This will increase to 5 MTPA. See Ex. 2 at Slide 4. There are also proposals to ship significant qualities of coal from the Vancouver and Roberts Bank facilities. Id. Cloud Peak

exports at least 3.3 MTPA from its Spring Creek Mine in the PRB out of Westshore , and potentially as much as 4. 7 MTPA from this port

. 2 The U.S. coal being shipped out of the Canadian ports is likely shipped via Washington through the Seattle and Tacoma area.

II. RAILROAD CONNECTIONS

A. Potential rail routes

BNSF Railway (formerly known as Burlington Northern Santa Fe ) has major rail lines

that stretch from the PRB to Washington, near Woodland and the port of Longview and Cherry Point. The port at Longview has eight berths, seven of which are rail accessible in varying capacities: directly accessible, direct transfer, transfer into storage and hopper to rail. The port at Cherry Point will feature berths for three ships and will be linked to the shore by a 1,250 foot trestle that will move cargo to or from the ships in enclosed

conveyor systems. 3

One rail route for Ca nadian or Cherry Point coal would be f rom Billings, MT, west to Sandpoint, ID, and then northwest to Cherry Point /Bellingham (All BNSF lines for the 1,003

rail miles ) . The same route extends to Canada. 4 Additionally Cherry Point is projected to be 48

- 54 MTPA. At volumes of 50 MTPA, that amounts to more than 22 loaded and coal trains

, each

more than a mile long.

B. Impacts on Kent, Seattle and Tacoma

The proposed coal export terminals will cause c ommunities along the rail line, from the Powder River Basin in Montana and Wyoming, to Idaho to Washington and beyond will experience increased rail traffic through their communities. In communities split by rail lines, this could significantly increase the amount of fugitive coal emitted into the air and water, impact local air quality from increased train and ship diesel emissions, delay traffic, cause delays for

2 See http://www.businesswire.com/news/home/20110614005387/en/Cloud

- Peak

- Energy

Agrees

- Terms

- Terminal

- Capacity#.Ux0_fIUlRgs ; See also http://online.wsj.com/article/PR

- CO

20140213

- 917200.html (Cloud Peak exported 4.7 MTPA to Asia in 2013.)

3 See http://www.gatewaypacificterminal.com/project/what.shtml

. 4 See http://www.wstc.wa.gov/Rail/RailFinalReport.pdf4

emergency vehicles, increase noise pollution, and enhance the likelihood of pedestrian accidents

and auto

- train collisions

.

There are several different communities across the western United States that

are currently and would in creasingly be impacted by coal trains on a daily basis. Below is a list

of some of the different rail routing scenarios through Washington:

• Utilizing the northern line out of Spokane the communities through which train s trave l include Wenatchee, Monroe (west side of Cascades), and then after meeting up with

the north

- south running line, Everett, north of Seattle.

• Taking the middle line out of Spokane the communities through which trains travel include Kennewick, Yakima ( including Yakima Indian Reservation ) , Ellensburg (on

outskirts of town), and then after meeting up with the north

- south running line, Auburn, just south of Seattle.

• Taking the southern line out of Spokane the communities through which trains travel include Kennewick, Vancouver turning north running along the I

- 5 corridor and hitting the town of Centralia , then Lakewood entering the Seattle

Tacoma area, where the line then meets with the middle line at Auburn. Running north from Auburn that line goes through Kent, Renton, Seat tle, Richmond, Edmonds, and then meets with the north line at Everett.

 At Everett all three lines merge and the one line runs north through Marysville, Mt. Vernon, Burlington

, Bellingham and into Canada

. See Ex . 2 ; See also The Kent, Seattle, and Tacoma, WA Second 10

- year limited maintenance plan for PM10, EPA

- R10

- OAR

0714

- 0004 ( Dk# 0004) at 5, 6 , 7 (map of rail line running through maintenance areas).

I II

. THE MAINTENANCE PLAN FAILS TO PROTECT KENT, SEATTLE AND

TACOMA FROM INCREASING PM10 EMISSIONS FROM COAL EXPORT

TRAINS

.

A. EVEN ASSUMING ALL THE ANALYSIS IN THE SIP SUBMITTAL

REGARDING THE CURRENT EMISSION INVENTORY AND AMBIENT PM10 LEVELS ARE CORRECT, THE SIP DOES NOT ENSURE THAT THE PM10 NAAQS WILL BE MAINTAI NED.

EPA explains that limited maintenance plans are appropriate when there is little risk of violating the PM10 NAAQS again. 78 Fed. Reg. at 78,311. The coal export trains create a substantial risk of Kent, Seattle

, and Tacoma violating the PM10 NAAQS again. Therefore

, EPA cannot approve this limited maintenance plan because it does not “ensure” maintenance

. See 42 U.S.C. § 7505a(a).

The 2011 emission categories include locomotives ( including fugitive dust ) . 78 Fed. Reg. at 78,313. The SIP submittal calculated 4.8 million tons per year of coal being shipped as5

part of the emission inventory. Actually, coal exports ranged from 30,581 tons in 2008 to 4,854,451 tons in 2011 during the period from which EPA is relying on ambient monitoring data.

Ex. 1 at Slide 3. As explained above, Cherry Point has the potential to require shipment of 5 2.5 million tons per year during the maintenance period. The Millennium Bulk Termi nal at Longview Project will ship approximately 4 8 million tons per year. Amber Energy’s Coyote Island Terminals, LLC will ship approximately 9 million tons per year. Thus, these three

facilities could result in over 100 million tons per year of coal shipped through the three

maintenance areas. See also Ex. 1 at Slide 4 (EPA acknowledges 134 million ton per year increase by 2022). This represents over a 20 fold increase based on the highest year and 3270 fold increase from the low ye ar. EPA itself said the “number of coal trains per day on rail routes

would significantly increase if these terminals are built.” Ex. 1 at Slide 6 (emphasis added). Even if we assumed that the coal bound for the Coyote Island Terminal would not pass thr ough any of the maintenance areas, we are still talking about an increase between 19 and 3073 fold.

EPA tries to dismiss locomotive (including fugitive dust) emissions because they are

current ly “small relative to other source categories” during what EPA claims is the critical winter day period. See EPA

- R10

- OAR

- 2013

- 0713

- 0007 ( Dk# 0007) at PDF page 2. But even if

locomotive (including fugitive dust) emissions were 2% of the inventory, a 19 fold increase

means a 36% increase in overall emissions (2*19 + 98 / 100 = 1.36). See Dk# 0007 at pdf page

2. A 36% increase in the emission budget for Tacoma could result in a design value of 89.75 ug/m3. Considering all the uncertainty in the design value (which is not based on actual PM1 0 monitoring) and the emission inventory (which is not based on any testing) a potential 89.75 ug/m3 design value means the SIP fails to “ensure” maintenance. Furthermore, on the other end of the spectrum, if Kent saw a 3073 fold increase in locomotive (including fugitive dust)

em issions, that would be an increase of 18,532% of the total emission budget. (6 * 3073 + 94

/100 = 18,532). An 18,532% increase over the Kent design value assumed by EPA, 46+/

- 3, would be no less than 8524.72 ug/m3 which significantly exceeds the NAAQS. For Seattle, if

we assumed the bottom of the range 19 fold increase, and also accept EPA’s assumptions of 5% of the current inventory being locomotive (including fugitive dust) and a design value of 50 +/

- 5 ug/m3, we would end up with a design value of 104.5 ug/m3 which is above the limited maintenance plan threshold of 98 ug/m3.

Calculated another way, the emission factor, according to the SIP submittal, is 0.0066 kg/ton for Seattle. If Seattle saw an increase of 100 million tons per year of coal from the Cherry

Point and Lo ng v iew terminals , the fugitives from the coal trains alone, not counting emissions from the diesel engines, would add 727 tons per year of PM10 or approximately double the total emission inventory from 2011. Even if one used the 85% control efficiency , which we strongly disagree with for the reasons explained below , there would still be an increase of 138 tons per year, converting locomotives (including fugitive dust) to the second largest source of PM10 in

the maintenance area.

For Kent, again, even accepting the un supportable control efficiency of 85%, the 100 million tons per year would add 55.3 tons per year of PM10 to the maintenance area. This would

make l ocomotives (including fugitive dust) the largest source of PM10 in the maintenance area

and increase the total emission invent ory by near 40%. If one used no control efficiency, because there is absolutely no support that any control efficiency will be achieved when the coal6

trains are running through the maintenance area, the emission factor yields an add ition of 368.5

tons per year of PM10. Total emissions that are 262% greater than the emissions in the 2011 emission inventory should surely be enough to not conclude that the Maintenance Plan will

ensure maintenance. Even if the increase was an extra 50 million tons per year being shipped, we are still talking about an increase in the total emission inventory of 131%. This is clearly a maintenance problem.

Sim il ar ly, for Tacoma, with the 85% unsupportable control efficiency, fugitives from the

coal trains alone would increase emissions by 43 tons per year or 8%. Doing the calculation properly by assuming no controls because there is no requirement in the Maintenan ce Plan for controls and there is no evidence that there is any controls yields an increase of 276.4 tons per year. This would change the locomotives (including fugitive dust) category from the smallest to the largest source category and increase total emissions by 52.3%. Increasing by ha lf is hardly ensuring mainten a nce.

Moreover, the above calculations underestimate actual emissions because we are just calculating increases in fugitive coal dust emissions. We are not adding in the additional

emissions from the diesel engines in the locomotives. WE are also not counting emissions from “empty” rail cars returning from the Port to the mines. Yet, this is a source of emissions which

has been re ported as being a source of “heavy fugitive dusting.” Ex. 3 at 25. Also, emissions

from the locomotive engines would be twice as high if the export facilities go into operation

because locomotive engines would have to bring the rail cars back to the mines.

We are not asserting that there is definitely a linear relationship between design values

and locomotive (including fugitive dust) emissions, although EPA certainly often relies on assumptions of such linear relationships in this and other rule making. Nevertheless, when

maintenance are as face the prospect of such dramatic increases in emissions in one source category during the maintenance period, those increases can create dramatic increases in overall emissions, and there are no regulatory mechanisms to address these increases current ly in place or in the contingency measure, EPA cannot rationally conclude that the maintenance SIP will ensure maintenance of the NAAQS.

The PM2.5 monitors do not provide adequate protection against future violations. To begin with, this is a maintena nce SIP, not a “catch future violations and do something to fix the future violations a couple of years later” SIP. PM10 can kill people and cause s a variety of other public health and welfare adverse impacts. It is no comfort to those who die during any future violations that the violation will be detected and may be addressed months or

, more likely

, years later. Rather, the plain language of the Clean Air Act provides that the SIP must “ensure”

“maintenance.” See 42 U.S.C. § 7505a(a).

Furthermore, the re are only PM2.5 monitors in the PM10 maintenance areas

. 5 EPA has no evidence about what percentage, if any, of the fugitive emissions from co al trains are larger

5 Should EPA refuse to require PM10 monitors, the contingency measure trigger needs to be clarified that it is triggered by PM2.5 monitors showi ng “violations” using the equivalency factors, not by PM10 violations at the FRM monitoring. Also, the Maintenance Plan cannot use the procedures outlines in 40 C.F.R. Part 50 because, again, there are no PM10 monitors. See Dk# 0007 at 36. While it is cl early illegal for the SIP to ignore Part 50, it is7

than PM2.5. PM2.5 monitors cannot physically monitor PM10

- 2.5 which is the size range coal dust may fall into. Likewise, there is no evidence in the record to establish that the span and range of the PM2.5 monitors are adequate to t hat they can record very high bursts of PM10, like the levels that are obviously present in the picture on the first page of these comments.

In addition, Washington switched to PM2.5 monitoring in 2007 but in 2008 coal exports were only 30,581 tons. See Dk# 0004 at 14, 15, 17, 19. Thus, there is no evidence that EPA’s claimed correlation between PM10 and PM2.5 took into consideration fugitive coal dust.

This is important because the co r relation between modeled and monitored PM10 readings is not particularly strong to begin with. See Dk# 0004 at 22. For example, one point in Figure 4.2.2 appears to show a modeled value of 20 ug/m3 which was actually a monitored value of approximately 47 ug/ m3. In other words, the actual value was over twice as high as the modeled value. Seattle also demonstrates values where the actual value is twice as high as the modeled

value. See Dk# 0004 at 24. Tacoma is even worse. One data point appears to have a mode led value of 23 ug/m3 but an actual monitored value of 95 ug/m3. A “ quasi

- monitoring ” method

that can under

- predict so significantly is not adequate to protect people against a pollutant which

can kill innocen t people.

Finally, the fact that the PM2.5 monitors are “nearby” to the trains does not establish that they will appropriately monitor PM10 from the trains. EPA offers no evidence that the placement of the monitors is appropriate for monitoring the trains. EPA doe s not define nearby. Nearby for one thing may not be nearby enough to accurately detect PM10 from trains. EPA also does not discuss the site specific meteorology where the trains and monitors are located. For example, EPA does not establish that the mon itors will not be “upwind” of the trains the vast majority of the time. Also, EPA does not discuss evaluation changes or other physical barriers, if any, between the trains and the monitors. The Kent monitor is a neighborhood scale site to be

representat ive of the Kent Valley Area, not coal trains. See Dk# 0004 at B30. The same is true of the 4401 E. Marginal Way, S monitor. Id. at B37. If EPA could resolve the other problems discussed above, which it cannot, EPA would have to use AERMOD or a similar mode l to ensure that the monitors are at locations where the maximum PM10 impacts are expected.

For all of the above reasons, EPA must disapprove the Maintenance SIP.

B. EPA’S EMISSION FACTOR UNDERPREDICTS PM10 EMISSIONS

FROM COAL TRAINS

Above, we demonstrated that even assuming the Maintenance Plan’s emission

calculations were correct, there could be a massive increase in PM10 emissions from coal export

trains duri ng the second maintenance period which the Maintenance Plan fails to address. Here,
we explain why the Maintenance Pl an’s emission calculations are not reliable.

also illegal and absolutely not protective for the SIP to require a violation to be determined pursuant to a procedure that it is impossible to use.8

The Maintenance Plan’s fugitive coal dust calculation is derived from a paper entitled “A
Study of Fugitive Coal Dust Emissions in Canada,” November 2001, by Douglas L. Cope and
Kamal K. Bhattacharyya (Cope 2 001)

. See Ex. 3; Dk # 0004 at C

- 16 and Ftnt 10. Cope 2001
was not published. Ex. 3 at iii. It ha d a “limited” technical review. Id.

The Maintenance Plan assumes 177 days of precipitation per year. Dk# 0004 at C

- 16. However, Cope 2001 acknowledges that “ Hot and dry weather ‘up route’ of the emissions can

influence the emissions at the point of observation.” Ex. 3 at 17. The Powder River Basin and
Idaho, which are up route of the three maintenance areas

, are very dry areas and can be very hot
during the summer . However, the Mainte nance Plan does not take this factor into its

calculations.

Similarly, the 2011 emission inventory does not take into account fugitive coal dust emissions from “empty” rail cars returning to the mines. Yet, this is a source of emissions. See

Ex. 3 at 35. Sometimes, this is because the coal in the car is frozen and thus does not get fully
dumped out before the return trip. Ex. 3 at 41.

It also very well could be the case that the emission factor used in the Maintenance Plan

double counts co ntrol. The basic emission factor that Cope used, 0.1 * (0.62*D) 0.6 , stated that it

was based on 75% control. Ex. 3 at 28

- 29. Yet, despite the fact that the basic emission factor
explicitly stated it already had built in a 75% control factor, Cope determ ined that it was an
uncontrolled emission factor and added in a provision to his formula to account for control. Id.

The basic formula also picks the low end of the range for coal loss versus the high end or
middle. That is, the range is 0.5 to 3% of t he total car load. The formula which the Maintenance
Plan ultimately relies on used 0.5%. Id . at 44.

Also, EPA uses a scaling factor for TSP to PM10 of 0.75 for truck loading, which is the

most similar situation to coal trains. Id. at 47. Yet, the Maintenance Plan uses a 0.5 scaling

factor. Thus, a scaling factor of 0.5 is inappropriate.

EPA acknowledges that the percent of dust control measures remaining at the end of the
journey effects the amount of fugitiv e coal dust. Ex. 1 at Slide 9, 14. However, EPA’s formula

does not take that factor into account.

According to BNSF, each coal car releases 500

- 2000 lbs of coal dust per trip, and thus a
typical 125 car train could lose up to 250,000 lbs of coal per trip. 6 The Maintenance Plan
assumes 85% control from a topping agen t or su rfactant that is applied to the top of loaded coal

cars at the mine

. Th is "requirement" is from a BNSF tariff to require the use of surfactants on

PRB coal. I n late 2013 , the Surface Transportation Board ( STB ) finally approved this tariff but

6 See Burlington Northern Santa Fe Railway, “Coal Dust FAQ,” Mar 2011, http://www.coaltrainfacts.org/docs/BNSF

- Coal

- Dust

- FAQs1.pdf

.9

it has no enforcement mechanism and is essentially voluntary . I ndustry has been quote d as
saying that many coal shippers are simply ignoring the tariff

— only 30% of coal shippers were
applying surfactants as of late 2011 7 . Even if coal shippers do not ignore the tariff

, surfactants

wear off over the rail route and are not 85% effective

— likely closer to 0% the furt her the coal
gets from the mine like in Washington. Further evidence and expert commentary o n the
inaccuracy of the 85% control efficiency assumption can be found at pages 7

- 9 of Phyllis Fox’s
Fugitive Particulate Matter Emissions from Coal Train Staging at the Proposed Coyote Island
Terminal, attached as Ex. 5 and incorporated herein by reference.

C. THERE IS OTHER RELIABLE EVIDENCE THAT INDICATES THE

UNREGULATED INCREASE IN COAL EXPORT TRAINS MEANS THE MAINTENANCE PLAN DOES NOT ENSURE THAT THE PM10 NAAQS

WILL BE MAINTAINED

In addition to the dramatic increase in the PM10 emission inventory that the coal export trains will cause, there is other reliable evidence that indicates the unregulated increase in coal export trains means the maintenance plan does not ensure that the PM10 NAAQS will be

maintained.

For example, Sierra Club had a modeling expert prepare an evaluation of the ambient air

qua lity impacts of the proposed Ambre Energy’s Coyote Island Terminals in Morrow, Oregon (Morrow). Khanh Tran produced a report entitled, “ The AERMOD Modeling of Air Quality Impacts of the Proposed Morrow Pacific Project.” See Ex. 4. The Morrow project invo lves trains to deliver approximately 8.5 million tons per year, which is significantly less than the approximately 100 million tons per year for Cherry Point and Longview combined

. See Ex. 1 at

Slide 4. The modeling analysis used an annual emission figur e of 12.8 tons per year PM2.5 from train cars and 0.92 tons per year from tug boats. Ex. 4 at 5. This is significantly less than the fugitive emissions in each of the maintenance areas which would come from coal trains bound for Longview and Cherry Point

. See above. AERMOD, the model used in Mr. Tran’s analysis, does not distinguish between PM10 and PM2.5 in terms of modeled impacts. Thus, results for

PM2.5 could be assumed to be PM10 if the emissions were PM10.

Even with these much smaller emissi ons, the modeling analysis predicted an impact of 388.6 ug/m3 with open trains and closed barges. Ex. 4 at 20. This value exceeds the PM10 NAAQS. Open trains is the appro priate scenario to look at because there is no requirement for the trains passing t hrough the maintenance areas to be covered. In any event, the emissions used in this scenario are still significantly less than the emissions calculated for the three maintenance areas, even assuming 85% control. This modeling analysis is a strong indica tion that the Maintenance Plan will not maintain the PM10 NAAQS in light of the proposed coal export

terminals.

7 Tavanger, Sayeh, “Some shippers not complying with BNS F coal dust tariff,” Nov 3, 2011,

Platts Energy Week , WUSA 9

accessed http://www. wusa9 .com/news/local/story.aspx?storyid=17332910

D

. THE MAINTENANCE PLAN SHOULD REQUIRE PM10 MONITORS IN

THE PM10 MAINTENANCE AREAS

The re are no PM10 monitors in Kent, Seattle

, and Tacoma. 40 C.F.R. § 58.14(c) says monitors can be discontinued if they meet the requirements of Appendix D. Appendix D says the monitoring system has to meet three objectives. The first is TO provide air pollution data to the general pu blic in a timely manner. 40 C.F.R. § 58, Appx. D, 1.1(a). Washington’s SIP does not require the collection of any data about PM10. Therefore, it does not meet the first objective. The second objective provides : “ Data from FRM, FEM, and ARM monitors for NAAQS pollutants will be used for comparing an area's air pollution levels against the NAAQS. ” 40 C.F.R. § 58, Appx. D, 1.1(b). The SIP violates this because there is no data from FRM, FEM or

ARM PM10 monitors.

The 2011 emission categories include locomotives ( including fugitive dust ) . 78 Fed. Reg. at 78,313. Fugitive dust includes dust in the PM 10

- 2.5 . It is not physically possible for a PM2.5 monitor to accurately serve as a surrogate for PM 10

- 2.5 because PM2.5 monitors cannot

detect PM 10

- 2.5

. Even if there was a past correlation between PM2.5 levels and the emission inventory , there is no mechanism to explain why the correlation would continue in the future.

IV. CONCLUSIO N

If you have any questions

, or require any addition data, please do not hesitate to contact us. Otherwise, we appreciate your careful consideration of these comments on this very important matter. We look forward t o EPA ’ s disapproval of the PM10 maintenance SIP

submittal s

.

Sincerely,

Robert Ukeiley

Counsel for Sierra Club