CITY OF PH ILADELPHIA Department of Public Health Environmental Protection Division Air Management Services

InterOffice Memo

To: File

From: Edward Wiener

Date: March 8, 2016

Subject: Clarifications Regarding RACT Certif ications and De-Minimis Determinations

Introduction:

The Clean Air Act (CAA) requires that mode rate (or worse) ozone nonattainment areas implement reasonably available control technolo gy (RACT) controls on all major sources of volatile organic compounds (VOC) and nitrogen oxides (NOx). Ph iladelphia County is part of the Philadelphia-Wilmington-Atlantic City mode rate ozone nonattainment area for the 1997 8- hour ozone NAAQS. The purpose of this docum ent is to clarify source-specific RACT certifications that were previously submitted and/or are being submitted as a SIP revisions to EPA. This document also addresses AMS’ re vised approach in determining sources (i.e., emissions units) which are “de-minimis” for 1997 8-hour RACT determinations.

RACT Certifications

By definition, a major source threshold is provided for RACT applicability based on the classification of the nonattainment area in which the source is located. For RACT purposes, a major source of NOx and VOC in Philadelphi a under the 1997 8-hour ozone NAAQS is that which emits more than 100 and 50 tons per year of NOx and VOC, respectively. AMS evaluated RACT controls for all major NOx and/or VOC emitting facilities in Philadelphia under the 1997 8-hour ozone NAAQS, and documented such eval uations for each facility in technical memorandums. The RACT evaluations have been submitted to EPA for approval as a revision to the Pennsylvania State Implementation Plan (S IP). A list of major NOx and/or VOC emitting facilities evaluated by AMS for 1997 8-hour ozone RACT is provided in Table 2 of this SIP revision.

AMS has evaluated RACT for a number of fac ilities that are major NOx and/or VOC sources under the 1997 8-hour ozone NAAQS and are su bject to previous case-by-case RACT determinations under the 1-hour ozone sta ndard, as approved in the SIP in 40 CFR 52.2020(d)(1). Based on these evaluations, AMS is certifying that the 1-hour ozone standardcase-by-case RACT controls for certain emissi ons units in certain major NOx and/or VOC emitting facilities continue to represent case-by- case RACT for the 1997 8-hour ozone standard. The technical memorandums document the RACT evaluation for each major NOx and/or VOC emitting facility in Philadelphia and include each certification as well as additional supporting information. AMS submitted on February 18, 201 5 or is submitting to EPA the technical memorandums as part of SIP revisions to address Philadelphia’s 1997 8-hour ozone RACT demonstration.

Further, AMS certifies that certain NOx and/or VOC emitting facilities that were subject to caseby-case RACT determinations under the 1-hour oz one standard, are no longer subject to RACT under the 1997 8-hour ozone standard because th ey have either shutdown or are no longer considered major sources of RACT, as defined above. These facilities have been identified by AMS in the November 1, 2014 Memorandum docume nt titled “1-Hour RACT Facilities not in 8- Hour RACT”, which was previously submitted to EPA as part of the on February 18, 2015 RACT SIP revision.

For those facilities that have shutdown, as listed in the aforementioned document, AMS further requests EPA to remove from the SIP (40 CFR 52.2020(d)(1)) any previous case-by-case RACT determinations approved under the 1-hour ozone st andard. AMS certifies that none of these shutdown facilities have active operating permits or air pollution licenses for any equipment, and that under Pennsylvania and Philadelphia regu lations, they cannot operate until further notification and issuance of applicable perm its. AMS has included appropriate supporting information for this certification in the Februa ry 18, 2015 RACT SIP revision for Philadelphia.

AMS clarifies that those NOx and/or VOC emitti ng facilities that are subject to case-by-case RACT determinations under the 1-hour ozone sta ndard and that are no longer major sources of NOx or VOC subject to RACT requirements under the 1997 8-hour oz one standard, continue to remain subject to the 1-hour ozone RACT determ inations in the Pennsylvania SIP under 40 CFR 52.2020(d)(1).

De Minimis Emission Sources

AMS has determined some emission units at certain major NOx and VOC emitting facilities to be “de minimis” due to their low potential emi ssions and not requiring fu rther RACT analysis. In the February 18, 2015 RACT SIP revision, AM S had defined “de minimis” emission sources by establishing as general guidelin es specific potential-to-emit (P TE) thresholds of 5 tons per year (tpy) for NOx and 2.7 tpy for VOC. Becau se sources or emissions units vary in characteristics such as age, size, and potenti al controls, AMS has decided to follow EPA’s recommendation to not establish specific cut-off thresholds in determining RACT applicability and changed this approach to determine de mini mis sources on a case-by-case basis. Sources which have been determined de minimis are t hose for which the installation and operation of controls would be unreasonable due to size and level of emi ssions, based on AMS engineering and permitting knowledge. See EPA Comment No. 8 in the January 9, 2015 Comment andResponse Document created by AMS. In this RACT SIP revision, revised case-by-case de minimis determinations have been provided for each affected emissions unit in the corresponding technical memorandums.