Document ID: EPA-R08-OAR-2017-0298-0170
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2017-07-13T04:00Z

Department of Environmental Quality
                                       
                                 Amanda Smith
Executive Director
                                       
                            DIVISION OF AIR QUALITY
                                 Cheryl Heying
Director

                      Department of Environmental Quality
                                       
                                 Amanda Smith
Executive Director
                                       
                            DIVISION OF AIR QUALITY
                                 Cheryl Heying
Director

			
                                State of Utah 
                                       
                                GARY R. HERBERT
Governor
                                       
                                   GREG BELL
Lieutenant Governor

                                       
                                State of Utah 
                                       
                                GARY R. HERBERT
Governor
                                       
                                   GREG BELL
Lieutenant Governor

                                       
195 North 1950 West :: Salt Lake City, UT                                                                                                                                                                 Mailing Address:  P.O. Box 144820 :: Salt Lake City, UT  84114-4820                                                                                                                 Telephone (801) 536-4000 :: Fax (801) 536-4099 :: T.D.D.  (801) 536-4414                                                                                                         www.deq.utah.gov
Printed on 100% recycled paper
									
                                                                               
                                                                               
                                                                               
                                                                    DAQE-016-10
                                                                               
December 16, 2010

Irene Heng
PacifiCorp, Inc.
1407 W. North Temple
Salt Lake City, Utah  84116

RE: PM10/PM2.5 Emission Credit Order

The EPA recently revised the 24-hour National Ambient Air Quality Standard (NAAQS) for particulate matter with an aerodynamic diameter of 2.5 microns or less (PM2.5), and set the standard at a lower level than the 1997 standard.  Utah County did not meet the revised standard and was formally designated as a "nonattainment" area in December 2009.  The Utah Division of Air Quality (DAQ) is now preparing a State Implementation Plan for this area to demonstrate how they will come into compliance with the new standard.  During the interim, DAQ has reviewed the current Utah County Emissions Credit Registry and determined the quantity of PM2.5 as a subset of the listed PM10.  These values are based on the original origin of the banked PM10 credits and EPA referenced conversion ratios (AP-42), emission inventories, and DAQ determined conversion ratios.

For PacificCorp, 197.04 tons per year (tpy) of PM10 originated from the closure of Geneva Steel, 11.9 tpy originated from the closure of the Hale Plant, and 12.6 tpy originated from the closure of the Fifteen Fifty/Red E Mix batch plant.  To calculate the ratio of PM2.5 emissions from these sources the following methodologies were used:  

 Geneva Steel: Using both Geneva Steel's emission inventory and AP-42, DAQ calculated that 80.96% of the banked PM10 emissions were PM2.5 emissions (PM10 = 37.52 tpy and PM2.5 = 159.52 tpy).
 Hale Plant: This plant was a natural gas fired plant, DAQ calculates that all PM10 is PM2.5 for natural gas (PM10 = 0 tpy and PM2.5 = 11.90 tpy).
 Fifteen Fify/Red E Mix: Using AP-42 Appendix B.2.2 for concrete batch plants, DAQ calculates that 29.41% of the banked PM10 emissions were PM 2.5 emissions (PM10 = 8.89 abd PM2.5 = 3.71).

This order establishes the PM2.5 emission credits listed below and confirms their entry into the Utah County Emission Credit Registry.
                                       
          Utah County Emissions Credit Registry for PacifiCorp, Inc.
                                   Pollutant
                            Previous Credits (tpy)
                    Credits Transferred by this Order (tpy)
                      Credits Created by this Order (tpy)
                         Total Emission Credits (tpy)
PM10
                                    221.54
                                   (175.13)
                                       
                                     46.41
PM2.5
                                     0.00
                                       
                                    175.13
                                    175.13
NOx
                                    666.30
                                       
                                       
                                    666.30
SOx
                                     41.60
                                       
                                       
                                     41.60

Please note that PM2.5 credits may be used to fulfill either PM10 or PM2.5 offsetting requirements, however, PM10 credits may only be used for PM10 offsetting requirements and not for PM2.5 offsetting requirements.

Please feel free to contact Camron Harry at (801) 536-4232 if you have any questions.

Sincerely,

M. Cheryl Heying, Executive Secretary
Utah Air Quality Board

MCH:CAH:kw