U.S. Forest Service Draft Comments: Wyoming RH SIP

September 30, 2009

General comment: The Wyoming 309(g) RH SIP is a detailed document which addresses all of the 

requested elements outlined in the FS letter submitted to Wyoming DEQ, dated 8/2006. Nevertheless, 

the FS has concerns regarding some technical approaches and policy considerations as outlined below.

General comment: The RH SIP does not appear to address visibility impacts at Savage Run Wilderness 

Area. Although this wilderness area is not one of the 156 Federal Class I areas, the State of Wyoming 

has determined that it should be managed as a Class I area. The State has officially declared Savage Run 

a Wyoming Class I area.

General comment: Multiple air quality modeling exercises (PRB Coal Review, Pinedale Anticline, and 

others) identify potential ongoing visibility impacts in Class I areas within Wyoming and in adjacent 

States such as South Dakota and Colorado. How has Wyoming utilized the information available in these 

documents in the context of the 309(g) RH SIP? How does Wyoming intend to utilize similar information 

in future iterations of the RH SIP process?

Chapters 4 and 5

Tables 4.2-1 and 4.3-1 show projected decreases in overall state SOx and NOx emissions. 

However the same tables show increases in SOx emissions from Area sources and NOx emissions

from Area sources and Oil & Gas sources by 2018. The subsequent PSAT model results 

(Figures 5.2.1-1, etc.) show increases in SOx impacts from Wyoming on the best and worst 20% 

days at all three Wyoming Class I areas. The PSAT model also shows increases in NOx impacts 

on the worst 20% days at YELL and BRID, and best 20% days at BRID. Because Wyoming is

required to demonstrate that the State is obtaining “its share of the emission reductions needed to 

meet the progress goal for the area”, per 40 CFR 51.308 (d) 3, the FS believes that increasing 

Wyoming’s impacts at Class I areas cannot be understood to be reducing Wyoming’s “share of 

the emission reductions.”

40 CFR 51.308 (d) 3 ...In establishing its long-term strategy for regional haze, the State must meet 

the following requirements:

...
(ii) Where other States cause or contribute to impairment in a mandatory Class I Federal area, the 

State must demonstrate that it has included in its implementation plan all measures necessary to 

obtain its share of the emission reductions needed to meet the progress goal for the area.

Figure 5.2.8-3. Where do all the EC emissions come from that cause 20% best days at BRID to have most 

EC from natural fire? In other words, how can “natural fire” be such a dominant fraction on these clean 

days? The WEP analysis shows the overwhelming majority of EC on the cleanest 20% days at Bridger are 

from “natural fire”; however, the cleanest days at Bridger principally occur in the winter when “natural 

fire” is rare compared to residential wood burning for example. 

Chapter 6 

The FS acknowledges Wyoming’s involvement in the SO2 backstop trading program, and the 

corresponding regional SO2 emissions reductions. This program may well be contributing to 

noted decreases in sulfate concentrations in the mountain west.

FS is resubmitting its comments on Wyoming’s non-EGU BART facility since the FS original 

submittal was beyond the deadline for the initial non-EGU BART comment period. FS intends 

that the non-EGU comments be considered at this time as official FS comments to the State of 

Wyoming regarding the SIP and associated BART strategies.

FS is resubmitting its comments on Wyoming’s EGU BART determinations for completeness.

Chapter 7

The FS concurs with EPA Region 8 in its letter dated 12 August, 2009, in that Wyoming’s 309 status does 

not absolve Wyoming of its requirement to perform reasonable progress analyses for SO2 at Class I areas 

that are not part of the 16 Colorado Plateau Class I areas.

Has Wyoming demonstrated that its plan represents greater visibility improvement than is expected to 

result from implementation of other requirements of the CAA?

40 CFR 51.308 (d) 1 ...

(vi) The State may not adopt a reasonable progress goal that represents less visibility improvement 

than is expected to result from implementation of other requirements of the CAA during the 

applicable planning period.
For example, Table 4.3-1 lists roughly 24,000 tons per year (TPY) of increase in NOx emissions from Area 

and Oil & Gas sources, and roughly 7,000 TPY of NOx reductions from BART (Point) sources. The 

additional reductions of roughly 50,000 TPY come from mobile source rules which would be counted as 

“other requirements of the CAA”. Not counting the mobile NOx reductions, Wyoming has chosen a 

reasonable progress goal that is a net addition of NOx, which represents “less visibility improvement...”

The use of a Q/d screening tool for evaluating reasonable progress controls seems reasonable for large 

stationary sources. Is Q/d based on unit emissions or facility/project emissions? Is it Wyoming’s intent 

to decrease the Q/d threshold for future planning periods, hence allowing more facilities to be 

considered? Does Wyoming DEQ have a list of all considered sources (not just those over Q/d=10) and 

the corresponding Q/d’s? If so, that list should be included in the SIP. How many additional sources 

would be included if Wyoming applied a Q/d of 9 for example?

A Q/d analysis does not practically address Area sources. How will Area sources be addressed under 

Reasonable Progress?

From the 309 (g) Technical Support Document on the Wyoming DEQ website, this table lists sources 

with Q/d >10. Please add to this table the identification of which sources were controlled, by what 

technologies, and whether under BART or Reasonable Progress.

Section 7.3.5 When will the phase II report be available?
Table 7.3.5-1 lists 16-36 $/ton for SNCR with 90-99% efficiency for compressor engines. Why not 

require this on all units?

Section 7.6

1. Neff, et al. 2008, suggest that roughly 75% of windblown dust is attributable to human activity. 

As such, it is not appropriate to use windblown as a reason for failure to achieve the URP.

6. While it is true that Western Class I areas are cleaner than their Eastern counterparts, that can 

make it less difficult to show improvement. That is, cleaner air is more sensitive to changes in 

pollution. This is why it is important to consider visibility impacts (e.g. $/dv) when determining 

control strategies.

Chapter 8

While tables 8.1.2.1-1 & 8.1.2.1-2 do an adequate job of demonstrating impacts from Wyoming

emissions on surrounding States’ Class I areas, documentation of the projected impacts from Wyoming

emissions on surrounding States’ Class I areas in the future is left in the 309 (g) Technical Support 

Document. All discussions belong in the SIP as part of the RP demonstration. 

The comment that impacts from Wyoming emissions are “a small portion of out-of-state visibility 

degradation” is subjective and perhaps misleading. For example, even if 18% of 14% is a “small 

portion”, that is on average over many days. The maximum daily contributions could be much higher. 

In other words, impacts from Wyoming could be very large on an episodic basis. Further, projections of 

future increases in Wyoming NOx impacts, (as shown below for best days at Mount Zirkel) could 

significantly increase Wyoming’s share of impacts even as surrounding States try to meet their 

reasonable progress goals.

P.130: “By 2018, NOx emissions from Wyoming are projected by the WRAP to decrease by 39,861 tons, 

which will help reduce Wyoming’s impact to out of state Class I areas.” While these emissions should 

decrease impacts on average, localized emissions increases could clearly cause some Class I area impacts 

to increase.

What is the final proposal for RP controls at Laramie Cement Plant? What are the actual NOx emissions 

at Laramie Cement Plant? Are they 524 TPY (Table 4.1 EC/R WY report) or 2080 TPY (Table 7-1 EC/R 

general report)?

The SIP proposes SCR for NOx control at Laramie River and Jim Bridger power plants. The FS supports 

these decisions.

Section 8.3.4 Wyoming states that RP rulemaking will be complete by 2013. It was noted above that 

the FS believes that Wyoming has not demonstrated that it is meeting its share of emissions reductions 

for Class I areas inside and possibly outside of Wyoming. The WRAP commissioned reports1,2 with 

supplementary information for “four factor analyses” for a variety of source categories. Many of these 

analyses suggest low cost controls for source categories with significant emissions. The reports were 

delivered in May of 2009. Why is this information not mentioned or incorporated in the current SIP 

draft (other than as addendums in the TSD)? 

Chapter 9

FS notes that Wyoming operates IMPROVE protocol samplers at Thunder Basin National Grasslands and 

Cloud Peak Wilderness. FS finds this information useful and wishes to acknowledge Wyoming’s efforts. 

The FS also acknowledges the support we receive from Wyoming in providing a site operator at the 

North Absaroka IMPROVE site. Wyoming’s cooperation in visibility monitoring is greatly appreciated.

Typographical Corrections:

Section 5.2.9. Should “Fine PM” be “fine soil”?

Table 7.3.4-2 Column 3 - Potential Emission Reductions (1000 tons/ yr). Should be TPY.
P167 . “In spite of the large number of growing uncontrollable sources in the WRAP region, however, 

Wyoming does see a net visibility improvement at the Wyoming Class I areas through 2018.” Should 

read “uncontrollable sources impacting the WRAP region...”?

References:

1. Supplementary Information for Four Factor Analyses by WRAP States May 4, 

2009, EC/R Incorporated.

2. Supplementary Information for Four-Factor Analyses for Selected Individual 

Facilities in Wyoming May 6, 2009, EC/R Incorporated.