EMISSIONS INVENTORY BASE YEAR FOR CRITTENDEN COUNTY NOx and VOC REPORTING REQUIREMENTS FOR THE NONATTAINMENT AREA UNDER THE 2008 EIGHT-HOUR OZONE NAAQS

This document provides a technical review of a revision to the Arkansas State Implementation Plan (SIP) to meet Clean Air Act (CAA) Emission Inventory (EI) reporting requirements for the Crittenden County nonattainment ar ea under the 2008 eight-hour ozone standards submitted by the Arkansas Commission on Environmental Quality (ADEQ) on July16, 2014.

A. General Requirements

Under the CAA sections 172(c)(3) and 182 (a)(1 ), states are required to submit emissions inventory (EI) information for all re levant sources for areas that are designated nonattainment for any of the National Ambient Air Quality Standards (NA AQS) for each area designated nonattainment for a NAAQS. On March 27, 2008, the United States Envi ronmental Protection Agency (EPA) lowered the primary and secondary eight-hour ozone NAAQS to 0.075 parts per million (ppm) ( 73 FR 16436)

. 1 On May 21, 2012, the EPA published in the Federal Register ( 77 FR 30088) final designations for the 2008 ozone standard. The Crittenden County area was desi gnated and classified as marginal nonattainment. The effective date of the final rule is July 20, 2012.

The EPA’s published the final 2008 ozone standa rd SIP requirements rule on March 6, 2015, which specified that states use 2011 as a base year to address EI requirements. The nonattainment area base year EI emission is due no later than 24 months from the July 20, 2012 effective date and then every three years thereafter. An emissions inventory is an estimation of actual emissions of air pollutants in an area. Volatile organic compounds (VOCs) and oxides of nitrogen (NOx) are known as “ozone precursors”, as they react with ox ygen and sunlight to form ozone. Mo tor vehicle exhaust and industrial emissions, gasoline vapors and chemical solvents emit NOx and VOCs. Controlling sources of NOx and
VOC emissions can lower ozone levels in the ambien t air. Thus, the emissions inventory for an ozone
nonattainment area contains VOC and NOx emissions. Th e EIs provide data for a variety of air quality planning tasks including establishing baseline emis sion levels calculating federally required emission reduction targets, emission inputs into air quality si mulation models, and tracking emissions over time.
The total EI of VOC and NO X for an area are summarized from the estimates developed for four general categories of emissions sources: point, area, mobile, and biogenic.

B. Background

The majority of NO X emissions in Crittenden County come from Area sources. Area sources are smallscale industrial, commercial, and residential sources that use materials or perform processes that generate emissions. These sources could include printing proc esses, industrial coating and degreasing operations, gas services, or structure fires. The sub-set of mobile sources known as on-road mobile sources (vehicles such as cars and trucks that normally travel on public roadways).

1 We refer to this NAAQS as the 2008 ozone NAAQS or standard.2008 Eight-Hour Ozone Standard (2008 to Present)

On May 21, 2012, Crittenden County was designated as a marginal nonattainment area with a design value of 0.082 ppm ( 77 FR 30088), based on ozone monitoring data from the period of 2006 to 2008.

1997 Eight-Hour Ozone Standard (1997 to Present)

In July 1997, the EPA announced a revised NAAQS for ground-level ozone. The EPA phased out and replaced the previous one-hour standard with an eight -hour standard set at 0.08 ppm to protect the public health against longer exposure to this air pollutant . The eight-hour ozone standard became effective on September 16, 1997.

Effective April 14, 2004, the Memphis Ozone N onattainment Area (MONA), which includes Crittenden County was designated nonattainment for the 1997 eigh t-hour ozone standard and classified as marginal.

C. EPA’s Analysis

The EPA reviewed the Arkansas submittal for consiste ncy with the EPA regulations. The following is a summary of the analysis based on the information provided by Arkansas.

The 2011 Base Year Inventory is the starting point for calculating the reductions necessary to meet the requirements of the CAA. Sections 172 (c)(3) and 182( b)(1) of the CAA require that nonattainment plan provisions include an inventory of actual emissions from all sources of relevant pollutants in the nonattainment area. The federal Air Emissions Repor ting Requirements (AERR) rule requires states to develop and submit periodic EIs to the EPA every three years. The 2011 inventory was the first periodic emission inventory (PEI) submitted under AERR. Per th e AERR, the 2011 PEI was reported to the EPA’s National Emissions Inventory (NEI) as a comprehensiv e and detailed estimate of air emissions, including ozone precursors (NO x and VOC). The year 2011 is also the year for a required EI submission under the existing AERR rule. As directed by the AERR, the NEI includes statewide coverage. Annual and summer day emissions are reported on a three-year cycle for the AERR. States can rely on periodic AERR EI submittals to satisfy ongoing SIP EI submission re quirements every three years. The Arkansas DEQ submitted the 2011 base year inventory to the EPA as part of a SIP revision for the Crittenden County 8-
hour ozone non-attainment area. The EPA reviewed th e 2011 base year inventory and determined that it was developed in accordance with EPA guidelines. Th e inventory includes all area, point, non-road mobile, and on-road mobile source emissions in th e Crittenden County ozone nonattainment area. The inventory also includes a description of the methods used to estimate emissions:

Point Source Emissions: Industrial sources are require d to submit emissions data to the ADEQ annually and certify that the data reported is accurate to the b est of their knowledge. The ADEQ stores the data in the State and Local Emissions Inventory System ( SLEIS). For the 2011 EI, facilities could use SLEIS to electronically submit their EI reports to the ADEQ for review. All submitted data is reviewed by the ADEQ for quality assurance purposes and then stored in the SLEIS database. At the end of the annual reporting cycle, point source emission data is reported each year to the EPA for inclusion in the National Emission Inventory (NEI).

Area Source Emissions: Area sources are small-scale indus trial, commercial, and residential sources that generate emissions. The ADEQ developed the 2011 area source emission inventory in accordance with the AERR reporting requirements, using methodologi es and data from EPA- prescribed methods in“Procedures for the Preparation of Emission Inventor ies for Carbon Monoxide and Precursors of Ozone Volume 1: Guidance for Stationary Sources” found at: http://www3.epa.gov/ttn/naaqs/aqmguide/collec tion/cp2/bakup/1991050 1_oaqps_epa-450_4-91- 016_ei_preparation_stationary_sources.pdf. The EPA developed EIs for states to us e for many source categories as part of the NEI. These source categories include but are not limited to industrial coatings, degreasing; residential, commercia l/institutional, and industrial fuel use, commercial cooking; aviation fuel use; and consumer products . We have reviewed these approaches and have determined that they are acceptable.

Non-road Emissions Inventory: The non-road category is composed of a diverse collection of equipment, many of which are powered by diesel engines. Non -road emissions sources include, but are not limited to: agricultural equipment, locomotives, drilling equipment, lawn and garden equipment, and drilling rigs. Arkansas utilized the National Mobile Inventory Model (NMIM) for this data. NMIM runs a series of models to calculate pertinent emissions, incl uding the NONROAD Model for non-road engines, equipment and vehicles. NONROAD has a primary func tion used for estimating air pollutant inventories by professional mobile source modelers, such as state air quality officials and consultants. We find the approach and methodology used by the ADEQ acceptable.

On-road Emission Inventory: On-road emission sources c onsist of automobiles, trucks, motorcycles, and other motor vehicles travelling on public roadwa ys. On-road mobile source emissions are usually categorized as either combustion-related emissions or evaporative hydrocarbon emissions. Combustionrelated emissions are estimated for vehicle engine exhaust. Evaporative hydrocarbon emissions are estimated for the fuel tank and other evaporative l eak sources on the vehicle engine exhaust. The ADEQ updated the on-road emissions us ing EPA’s Motor Vehicle Emissions Simulator (MOVES2010b) for onroad mobile sources. In April, 2012, the EPA re leased MOVES2010b with several improvements to the general model performance. To calculate pollution from on-road mobile sources, emission rates are estimated as a function of county, vehicle type, road way type, hour, and operating speed. These rates are then matches with appropriate activity from transpor tation data parameters incl uding- but not limited tovehicle miles travelled, number of vehicles parked, and hours spent in idle mode. The EPA reviewed the on-road emission estimates approach and methodolog y and determined that they are acceptable.

The 2011 base year emissions data for Crittende n County are provided in Table 1 below.Table 1- Base Year Emissions Inventory, 2011 Data Category Ozone Season Daily NOx Annual NOx Ozone Season Daily VOC Annual VOC

Units Tons/day Tons/year Tons/day Tons/year

Point 0.0017 .063 .051 186.84

Area 8.70 3,165.17 24.90 8,868.94

Non-road Mobile 2.11 582.63 3.66 881.35

On-road Mobile 6.80 2,542 2.42 845

Total 17.61 6,290.43 31.49 10,782.13

Biogenic Sources: Biogenic sources include VOC emissions from crops, lawn grass, and trees as well as a small amount of NOx emissions from soils. Plants are sources of VOC emissions such as isoprene, monoterpene, and alpha-pinene. Biogenic emissions are estimated by the EPA using its biogenic emissions inventory tool.

D. Summary and Recommendations:

Pursuant to 40 Code of Federal Regulations Part 51.102 and after proper notice, the ADEQ conducted a public hearing to consider the EI re vision to the SIP. Proper notice included prominent advertisement in the areas affected at least 30 days prio r to the date of the hearing. The public hearing was held in West Memphis on March 18, 2015. Data, vi ews, and recommendations of interested persons regarding the proposed SIP revision were submitted to the ADEQ during the comment period and were considered for the SIP revision. The ADEQ has used acceptable techniques and methodologies to develop the 2011-base year emission inventories for the 2008 ozone NAAQS for Crittenden County to satisfy
sections 172 and 182 of the CAA.

Therefore we recommend approval of the Arkansas State Implementation Plan (SIP) revisions to meet the CAA EI reporting requirements for th e Crittenden County nonattainment area under the 2008 ozone NAAQS, submitted by the ADEQ on August 28, 2015 .