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Addendum Responding to Questions Received

Question Response

1. Where are the EPA designated Class I park areas to be 

protected by this EPA proposal?

EPA did not designate Class I areas. These were designated by 

Congress (see section 162(a)). The Class I areas relevant to this 

rulemaking are identified in Table 8 of the proposal (Caney Creek 

Wilderness Area (AR), Hercules Glades Wilderness Area (MO), 

Upper Buffalo Wilderness Area (AR), and Wichita Mountains 

Wilderness Area (OK).

2. How and with what authority and with what State input were 

these parks designated as Class I areas?

As noted above, Class I areas were designated by Congress.

3. How far and in what direction is each of these parks from the 

specific Oklahoma OGE and PSO coal-fired power plants targeted 

by this EPA proposal?

Distances can be found in Appendix B, Table 1-1 of the Technical 

Support Document (TSD). Maps provided in the TSD indicate 

direction. Please see Figure 1-1 in Appendix B of the TSD.

4. How many other coal-fired power plants of what size are located 

closer to or at similar distances from the parks in question?

For the FIP EPA evaluated the BART eligible sources within 

Oklahoma. Table 2 of the proposal lists Oklahoma’s BART eligible

sources. For this rulemaking, EPA did not identify other BART 

eligible coal-fired power plants located closer to or at similar 

distances from the Class I areas within Oklahoma. Other nonBART eligible coal-fired power plant sources are: Grand River 

Dam Authority Chouteau Plant, Unites 1 (520 MW) and 2 (490 

MW), in Mayes County Units 1 and 2 in Mayes County; Western 

Farmers Electric Cooperative, Inc. Hugo Plant, Unit 1 (446 MW) in 

Choctaw County; OG&E Muskogee unit 6 (572 MW); and AES 

Shady Point a coal-fired cogeneration plant (2 units, 320 MW total) 

in Le Flore County.

5. From EPA's modeling analyses on how many days is visibility 

expected to be diminished in each park area and to what extent is 

it expected to be diminished on these days?

See our Response to Modeling Comment #1 in the final 

rulemaking for the number of days visibility impacts from an 

individual facility’s BART units is over 0.5 deciviews and 1 

deciview.

6. In what seasons are these "impact days" expected to occur at 

each park and how many of these days are single days compared 

to continuous multiple days?

Observed and modeled visibility impacts, as well as day of the 

year, for each of the 20% worst days in 2002 are provided in 

Figure 4-8 of Appendix A of the TSD and Appendix D of the 

CENRAP TSD. We note that the monitor takes a sample every 

three days, year round. In modeling for individual source impacts 

on a Class I area, we examine the 98th percentile or 8th highest 
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impacted day consistent with the BART guidelines. 

7. Has EPA provided "Seasonal Wind Roses" that would allow 

Oklahoma citizens and officials to understand how and when the

targeted power plants could affect these remote parks that most 

people would not consider to be downwind of these plants?

As discussed in the TSD, CALPUFF visibility modeling was 

performed using three years of prognostic meteorological data. 

This meteorological data is more sophisticated than wind rose 

data. In modeling for individual source impacts on a Class I area, 

we examine the 98th percentile or 8th highest impacted day 

consistent with the BART guidelines. Because we evaluate 

visibility impairment on a 24-hr basis, seasonal wind patterns were 

not directly considered in our decision. Please see Appendix W of 

40 CFR 51 (Guideline on Air Quality Models, 8.3.1.2(d)). 

8. For each park how many visitors are expected by season 

currently and how many are forecast by season for various future 

years?

EPA does not forecast the number of visitors to Class I areas. 

This factor is not considered under Sections 169A and 169B of the 

CAA or the RH rule.

9. What additional annual and total costs does EPA believe will be 

required for OGE and PSO to comply with EPA's proposal?

As part of the FIP, this action includes a thorough evaluation of the 

cost of compliance for the six units. EPA’s evaluation includes 

both annual and total costs in accordance with guidance and the 

RH rule. See the revised Cost Estimates included in this final 

rulemaking. 

10. Since these costs must be paid by Oklahoma's electric 

ratepayers for each utility, how much additional annual cost does 

EPA expect must be paid by each ratepayer/customer for each 

utility?

EPA does not have expectations of what costs must be paid by 

each ratepayer/customer for each utility because the CAA and the 

RH rule do not contemplate this factor as part of the BART 

analysis. 

11. Considering the additional annual costs for OGE and PSO 

compliance compared to the current and expected visitor days in 

which visibility would be expected to be impacted (i.e. "visitor 

impact days"), what does EPA consider to be the effective cost per 

potential "visitor impact day"?

As required by the CAA, EPA has considered, among other things, 

the cost of compliance and expected visibility improvement. While 

EPA believes the controls to be cost effective, EPA has not 

estimated an effective cost per potential "visitor impact day”. The 

CAA and the RH rule do not proscribe that states or EPA estimate 

a benefit of removing “visitor impact day.” Instead, the RH rule 

quantifies improvement in visibility using the deciview as the unit 

of measurement. For additional information on the visibility 

improvement of this FIP, see our responses to the Modeling 

Comments in the final rulemaking and the TSD.

12. What is the estimated benefit of removing these "visitor impact 

days"?

13. What is the ratio of the Cost to the Benefit of this EPA 

proposal?

The CAA requires our BART analysis to evaluate both the cost of 

compliance and the degree of improvement in visibility resulting 

from the addition of controls. As directed by Congress, EPA is 

obligated to consider in determining BART (1) the costs of 

14. Does EPA feel an obligation to consider the Cost/Benefit Ratio 

in its decision to proceed with this Regional Haze proposal which 
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only relates to aesthetics and not to health? compliance, (2) the energy and non-air quality environmental 

impacts of compliance, (3) any existing pollution control 

technology in use at the source, (4) remaining useful life of the 

source, and (5) degree of improvement in visibility which may 

reasonably be anticipated to result from the use of such 

technology. CAA section 169A(g)(2). For more information on 

this evaluation, see the TSD and the revised cost evaluation. As 

stated above, the CAA and the RH rule do not provide for a 

Cost/Benefit analysis that the commenter describes. 

15. Has EPA estimated a fraction of the year the emissions would 

need to be controlled at each of the targeted plants to meet these 

regional haze objectives?

Under 40 CFR section 51.301, Best Available Retrofit Technology 

(BART) means an emission limitation based on the degree of 

reduction achievable through the application of the best system of 

continuous emission reduction for each pollutant which is 

emitted by an existing stationary facility. Consistent with the 

definition of BART in 40 CFR 51.301, we evaluated controls based 

on continuous operation. Therefore, upon the effective date of our 

rule, the regional haze controls that will be necessary to meet the 

SO2 BART emission limit of 0.06 lbs/MMBtu at the six OG&E and 

AEP/PSO units must operate continuously whenever the units are 

generating electricity. Please see the federal register notice 

associated with the rule for more detail.

16. Has EPA considered the adverse regional economic impact 

and the adverse impact on Oklahoma's economy that would result 

from this proposal?

After careful review of cost and visibility benefits EPA determined 

that controls are cost effective. Our evaluation found that 

compliance costs would be significantly less than estimates 

provided by the State of Oklahoma.

17. Has EPA fully considered its moral and legal authority under 

the Clean Air Act that would provide the confidence that it would 

prevail in the courts on its decision to overrule Oklahoma's state's 

rights by rejecting the plan, and even by the earlier designation of 

these three Class I air quality areas and even the continuation of 

the national parks if the states object to these designations?

EPA has fully considered its authority and obligations in 

undertaking this rulemaking. EPA has a mandatory duty under the 

CAA to act on Oklahoma’s RH SIP. Because we have determined 

that portions of the SIP are not adequate to meet the requirements 

of the CAA and federal regulations, EPA is obligated to partially 

disapprove the SIP and implement a FIP. As stated above, 

Congress designated the Class 1 areas in CAA section 162(a). 

EPA has no authority over the continuation of national parks. 
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Questions related to the Wichita Wildlife Refuge Response

1. What study has been done to determine what part of that haze 

is caused by the natural emittents from the trees and the fauna in 

that area? 

Section 6 of Appendix A of the TSD discusses the types of source 

categories, source regions and pollutant species that contribute to 

visibility impairment at Wichita Mountains. Emissions from 

biogenic sources, motor vehicles, agricultural activities and other 

area sources are all included in the emission inventories used to 

model and project visibility conditions. 

As discussed in the TSD, CALPUFF visibility modeling was 

performed using three years of prognostic meteorological data. In 

modeling for individual source impacts on a Class I area, we 

examine the 98th percentile or 8th highest impacted day consistent 

with the BART guidelines. Please see Appendix Y of 40 CFR 51. 

2. What study has been done to determine how much of the haze 

is caused by the artillery firing at Fort Sill?

3. How much of the haze has been caused by highway traffic in 

Lawton and what study has proven this.

4. How much of the haze has been caused by farmers plowing 

and the dust that will create haze in the air.

5. How much of the haze has been caused by coal-fired plants or 

any kind of plant in Texas which is south down or upwind from the 

prevailing winds that blow in Oklahoma? 

6. I would really like to understand how those pollutants, those socalled pollutants from the clean burning coal-fired plants in 

Oklahoma that are under discussion, how can that pollution travel

that 200 miles against the prevailing winds to create that haze 

there?