Re:

Secretaryos Order No. 2012-A-0042

REVISIONS TO DELAWARE STATE IMPLEMENTATION PLAN FOR

REDESIGNATION REQUESTS AND MAINTENANCE PLANS UNDER

THE 1997 ANNUAL AND 2006 DAILY F'INE PARTICULATE MATTERNATIONAL AMBIENT AIR QUALITY STANDARDS

Date of Issuance: November 27,2012

Effective Date: November 27, 2012

This Order of the Secretary of the Department of Natural Resources and

Environmental Control (Department) approves two proposed revisions to the Delaware

State Implementation Plan (SIP). The revisions reflect significant improvements in New

Castle County's air quality that allow Delaware to seek the Environmental Protection

Agency's (EPA) redesignation of New Castle County's air quality status from'ononattainment" to "attainment" for the 1997 annual and 2006 daily fine particulatematter (PM z.s) National Ambient Air Quality Standards (NAAQS), as adopted by EPA.

Background

The Department administers Delaware's SIP, which reviews and reports to EPA

on the progress taken to have Delaware's air quality meet the federal standards. The SIP

provides EPA with air quality data, regulations, source specific requirements, plans andemission inventories on Delaware's current and fi.rture compliance with federal

requirements such as NAAQS. Delaware's SIP, as approved by EPA, is codified withinEPA's regulations at 40 C.F.R. Part 52, Subpart I.
received comments lron EPA. No member of the public attended the public hearing and

the Deparhent's SIP rcvisions dated October 23,2012, as attached to the hearingoflicer's report and as incorporated herein, reflect EPA's comments.

-lhe Departrnent's presiding hearing ol1ìcer recommends that the proposed PM2 5

SIP revisions for annual and daily PM zs dated Oclober 23,2012 be approvcd by an

Order of the Department and that the approved PM2 5 SIP revisions be submilted to El,Afor its approval.

Findings and Ilcasons

The Departmcnt finds that the record supports approval of the October' 23,2012

PMu.s SIP revisions for daily and annual NAAQS. 'l'he SIP revisions set forth the

regulatory steps that l)elawarc has taken to improve air quality 1o meet PM 2 5 daily andannual NAAQS. The PMz.s SIP revisions describe the air monitoring data and theinventory of sources of emissions. 'lhe PMz s SIP revisions explain that the air quality

monitoring dcmonstrate that New Caslle County's air quality should be changed from"nonall.ainment" to "attainment" for fine PM emissions, which includes "any airborne

parlicle of solid or liquid matter that is less than ol equal to 2.5 micrometers in diameter."

T'he PM2 5 SIP revisions explain thal the PMz s pollutant standard is measured as

the sum of all pollutants that havc diameters less than 2.5 micromelers, which is a sizeequal to about l/3011'the diameter oi'a human hair. EPA designated New Castle County
reduoe air pollutants. particularly nitrogen oxides and sullur dioxide air ernissions, thatare signifìcant contributors to PM pollution that caused the nonattajnmenl designation.

Significanr reductions in sullir dioxide and nitrogen oxides emissions were

realized through federal and state regulalory efforts. Thesc eflolts include: l)l)epaúment Regulation 1146,7 DI:a Admin Code 1146, which irnposed lower emissionlimits for pollutants emitted by large coal burning electric generating units,2) numerous

on and off road regulations the reduced emissions from mobile sources, and 3) thercgulatory aclion in court via a Consent Decree to curb air pollution from the DelawareCity Rel'ìnery.

'fhe PMz s. SIP revisions also set forlh maintenance plans that demonstrate

Delaware's continued compliance with the fine PM limits in the future through 2025.

-fhese maintenance plans sets for the response to any violation or exceedence in the PMIimits thal includes the neoessary regulatory actions that may be taken to r.emain in

cornpliance with the attainment designation.

The record establishes that the PM25 SIP revisions should be approved bascd

upon Delaware's sucoessful efforts to improve air quality and reduce fine particulalc

emissions to meet the BPA limits. 'l'he redesignations will reflecl New Castle Counly'simprovcd air quality and be consislent with thc implovements also aohieved withinEPA's entirc Philadelphia region that inoludes the Pennsylvalia counlies of Bucks,
the advelse consequences ofbeing a nonattainment area to those who live and wolk thet'enow and to those who may want to livc and work in New Castle County. Seoond, theredesignations will reflect the sucoess ol'the Department's many regulatory efl'orts taken

to improve air quality and the achievement of the goal of attaining the PM NAAQS.

'l'hitd, the redesignations will enhance New Castlc County's ability to retain industry andto attract induslry that may lequire air permils for new and modified majot stationarysources. 'l'he redesignations will change in the air permit prooess because new ormodified stalionary sources will no longer be required to meet thc federal and state New

Source Review (NSR) permit requirernents that applies to nonaltainment areas. Instead,

new ol modified sources will follow permit rcquircments for Prevention of Significantl)eterioration (PSD), which will protect the air quality and allow New Castle County tô

continue to meet the PM2 s NAAQS.

'l'he l)epartment fìnds that the PMz s SIP revisions should be adopted and

submitted to DPA for approval. Approval of the PM2.s SIP revisions in final is supported

by the record and consistent with the Depaltment's delcgated duties under the federalClean Air Act. In conclusion, the following fìndings and oonclusions are entered:

1. 'l'he Department finds the proposed Oclober 23,2012 PM2 s SIP revisions

are well supported by the record and should be adopted as a final PM2 s SIP rcvisions;