### RE: Fw : Class I Area Impact Analysis for PSD Permit Application Class I Area Impact Analysis for PSD Permit Application Dwight Mallory Dwight Mallory to: 'Don_Shepherd@nps.gov' 08/29/2012 02:19 PM

Cc: Andrew Chew, "' john _notar@nps.gov'", "John_Reber@nps.gov", "Michael_George@nps.gov", Patrick Flynn, "thormel@mcvehil-monnett.com"

Mr. Shepherd,

Thank you for your reply concerning the Class I are a screening. I have asked Tom Hormel at McVehil-Monne tt and Associates to assess the visibility impacts at Hovenweep for inclusion in the Additional Impacts Analysis. After he has results, we will provide the m to you and EPA Region 9.

Dwight E. Mallory Environmental, Health & Safety Coordinator Resolute Energy Corporation 1675 Broadway, Suite 1950 Denver, CO 80202 Direct: 303-573-4886 X 1165 Cell: 970-302-8620 Email: dmallory@ResoluteEnergy.com

-----Original Message----- From: Don_Shepherd@nps.gov [ mailto:Don_Shepherd@nps.gov] Sent: Wednesday, August 29, 2012 2:52 PM To: Dwight Mallory Cc: Chew.Andrew@epamail.epa.gov; 'john_notar@nps.gov'; John_Reber@nps.gov; Michael_George@nps.gov; Patrick Flynn Subject: RE: Fw: Class I Area Impact Analysis for P SD Permit Application

Mr. Mallory,

Based upon the information provided, our Q/d screening method indicates that no analysis of the project's impact on Air Quality Related Values for any NPS Class I area is needed. Please note that th is does not eliminate the need for NAAQS and increment analyses as required by the permitting authority. And, as noted in my previous email, we would appreciate inclusion of visibility impacts at Hovenweep National Monument as part of the "Additional Impacts Analysis" portion of any requir ed PSD analysis.

Don Shepherd National Park Service Air Resources Division 12795 W. Alameda Pkwy. Lakewood, CO 80228 Phone: 303-969-2075 Fax: 303-969-2822 E-Mail: don_shepherd@nps.gov "the man who really counts in the world is the doer ,not the mere critic "

TR 1891

Dwight Mallory <Dmallory@resolut eenergy.com> To

"'Don_Shepherd@nps.gov'" 08/10/2012 03:11 <Don_Shepherd@nps.gov>
PM

cc

"'john_notar@nps.gov'"

<john_notar@nps.gov>,

"Chew.Andrew@epamail.epa.gov"

<Chew.Andrew@epamail.epa.gov>, Patrick Flyn n

<Pflynn@resoluteenergy.com>,

"John_Reber@nps.gov"

<John_Reber@nps.gov>,

"Michael_George@nps.gov"

<Michael_George@nps.gov>

Subject RE: Fw: Clas s I Area Impact Analysis for PSD Permit Application

Mr. Shepherd,

Thank you for your reply. The requested hourly maximum emission rates and annualized emissions derived from the maximum hourly rates for NOx, SO2 and PM10 are included below and in the attached spreadsheet. The flare is not a direct source of H2SO4.

I will speak with Mr. Chew at EPA and our modelerabout the visibility impact analysis for Hovenweep

and will follow up with you.

Requested Emissions NOx: Hourly maximum rate - 27.1 lb/hr; Annualized maximum - 118.5 TPY SO2: Hourly maximum rate - 72.9 lb/hr; Annualized maximum - 319.1 TPY PM10: Hourly maximum rate - 3.1 lb/hr; Annualized maximum - 13.8 TPY

Dwight E. Mallory Environmental, Health & Safety Coordinator Resolute Energy Corporation 1675 Broadway, Suite 1950 Denver, CO 80202 Direct: 303-573-4886 X 1165 Cell: 970-302-8620 Email: dmallory@ResoluteEnergy.com

-----Original Message----- From: Don_Shepherd@nps.gov [ mailto:Don_Shepherd@nps.gov] Sent: Wednesday, August 08, 2012 9:51 AM To: Dwight Mallory Cc: 'john_notar@nps.gov'; Chew.Andrew@epamail.epa.gov; Patrick Flynn; John_Reber@nps.gov; Michael_George@nps.gov Subject: Re: Fw: Class I Area Impact Analysis for P SD Permit Application

Mr. Mallory,

Thank you for the information on the McElmo Creek Unit Gas Compression Facility. Our current (FLAG) guidance requests that you calculate the annual emissions of SO2, H2SO4, NOx, and PM10 (Q) by annualizing (multiply by 4.38) the maximum potentia l hourly emission rates of those pollutants. Please provide those hourly maxima.

I noticed that the site is near Hovenweep National Monument, yet i saw no mention of Hovenweep in the attachments. While Hovenweep is not a Class I area, we request that the impact of the flare's plume on visibility at Hovenweep be evaluated as part of the "Additional Impacts Analysis" portion of any requir ed PSD analysis.

Please feel free to contact me with any questions.

Don Shepherd National Park Service Air Resources Division 12795 W. Alameda Pkwy. Lakewood, CO 80228 Phone: 303-969-2075 Fax: 303-969-2822 E-Mail: don_shepherd@nps.gov" the man who really counts in the world is the doer ,

not the mere critic" TR 1891

John Notar/DENVER/NPS

To 08/06/2012 04:45 Don Shepherd/DENVER/NPS@NPS
PM

cc John Notar/DENVER/NPS@NPS

Subject Fw: Class I Area Impact Analysis for PSD Perm it Application

Don: my opinion is to screen this one out. It is 58 km west of MEVE & 92 km Southeast from CANY. I screened this one out back in June 2006. the SO2 emission estimates from the flare have gone dow n a small amount from 29.2 -> 26.7 TPY. They claimed that EPA Region ( made them run refin ed AERMOD to show compliance with the new 1-hour SO2 NAAQS. AERMOD show they do not cause or contribute to a 1-hour NAAQS violation. (Why Region 9 & not Region 8 is confusing, its in Utah. Dwight Mallory has left me a voice mail. As I said I recommend that we screen this out any ideas? My Q/D is : 60 TPY SO2 + 13.4 TPY NOx + 95.4 TPY VOC = 168.8Q / 58 km D = 2.91

John

----- Forwarded by John Notar/DENVER/NPS on 08/06/2012 04:27 PM -----

Dwight Mallory <Dmallory@resoluteenergy

. com >

To

"'john_notar@nps.gov'" 08/02/2012 01:28 <john_notar@nps.gov>
PM

cc

"Chew.Andrew@epamail.epa.gov"

<Chew.Andrew@epamail.epa.gov>, Patrick Flyn n

<Pflynn@resoluteenergy.com>

Subject Class I Area Impact Analysis for PSD Permit Application

Mr. Notar,

In reference to the voice message exchanges we have had: I am contacting you in reference to a PSD perm it application, submitted to U.S. EPA Region 9 on December 5. 2005, for the emergency flare at t he McElmo Creek Unit Gas Compression Facility, located near Aneth, Utah. Resolute Natural Resources Compan y acquired the MCU facility from Exxon Mobil in 2006 and we have been working with Region 9’s permitting staff to obtain issuance of the PSD permit since th at time.

You provided comments at the time the original PSD application and air modeling were submitted that no additional modeling for Class I impacts was necessary. However, since that time, EPA has promulgated new 1-hr NAAQS for NO2 and SO2, and requested that Resolute revise the modeling to account for the 1-hr NO2 and SO2 NAAQS. They also requested that Resolute contact you and allow the opportunity for you to review your commen ts in light of the 2010 revisions to the air emissions guidance for federal land managers.

The emissions limits of 60 TPY S02; 73 TPY CO; 13.4 TPY NOx; and 95.4 TPY VOCs applicable to the flare are unchanged since the original PSD application wa s submitted; and the flare’s actual emissions havedecreased from the 29

. 2 tons S 02 ; 66 tons CO ; 12

. 1

tons NOx; and 90.6 tons VOC reported by EOM for 200 5 to 26.7 tons SO2; 45.4 tons CO; 8.4 tons NOx; and 54.9 tons VOC for 2011. The SCREEN 3 model submitte d with the PSD application estimated near-field impac ts from the flare operating at 14.83 MMCFD for the entire year, or 7 times greater than the average ra te for 2005.

The results of the model showed that the flare did not cause or contribute to a violation of the National Ambient Air Quality Standards for NO2 or S O2 that were effective at the time of the PSD submitta l. The revised SCREEN 3 model demonstrated that the flare did not to cause or contribute to a 1-hour NO 2 NAAQS violation, but showed that the maximum 1-hr S O2 impact for the flare exceeded the interim SIL of 3 ppb. At Region 9’s request, Resolute remodeled the SO2 emissions using EPA’s refined AEROMOD model and was able to effectively demonstrate that the flare does not cause or contribute to a 1-hour SO2 NAAQS violation.

I have attached Appendix D of the original PSD application, which includes the original communication between yourself and Justin Harrison at Exxon Mobil concerning impacts to Class I areas. Al so attached is a map showing the location of the proje ct in relation to Class I areas. Please review and let me know if any additional information or modeling i s necessary.

If you would like to speak with EPA Region 9 staff, please contact Andrew Chew at (415) 947-4197.

As requested by Region IX, I have also contacted Laura Romin with USFWS to allow an opportunity for USFWS to renew their comments regarding T&E species and critical habitat impacts.

Dwight E. Mallory Environmental, Health & Safety Coordinator Resolute Energy Corporation 1675 Broadway, Suite 1950 Denver, CO 80202 Direct: 303-573-4886 X 1165 Cell: 970-302-8620 Email: dmallory@ResoluteEnergy.com [attachment "APP D from EOM PSD Ap.pdf" deleted by Don Shepherd/DENVER/NPS] [attachment "MCU Class I Air.pdf" deleted by Don Shepherd/DENVER/NPS]