SUBJECT: Technical Support Document (TSD) for Direct Final Rule to add the Definition of 

Greenhouse Gas, and Prevention of Significant Deterioration (PSD) Plantwide Applicability Limits 

(PALs) Revisions, State of Iowa 

FROM: 

TO: 

THRU: 

Heather Hamilton ftAE. -''" 1-t.tt 

Iowa State Manager 

A WMD/APDB/CPPS 

IA-131B and IA-159 

Amy Algoe-Eakin 

Section Chief 

AWMD/APDB/AtPS 

Mike Jay Branch Manager 

AWMD/APDB 

This direct final action will address two submissions from the State of Iowa as follows: 

• IA-131B: On November 18,2008, the Environmental Protection Agency (EPA) received 

a state implementation plan (SIP) revision from the State of Iowa that included the 

definition of"greenhouse gas" and added greenhouse gases to the air emissions inventory 

requirements. EPA did not act on these provisions in the direct final notice that was 

published on December 29,2009. 74 FR 68692. 

First, the federal definition of "greenhouse gas" was codified at 40 CFR 86.1818-12( a) on May 7, 2010 

(75 FR 25686) to read as follows: "This section contains standards and other regulations applicable to 

the emissions of the air pollutants defined as the aggregate group of six greenhouse gases: Carbon 

dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride." 

Iowa's definition (567 lAC 20.2) of"greenhouse gas" reads as follows, and is being added into the SIP 

with this action: "Greenhouse gas" means carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride." 

Printed on Recycled Paper 
federal amendments to the PSD program. Specifically, Iowa requested revisions to Iowa 

Administrative Code (lAC) 567 Chapter 33 - "Special Regulations and Construction 

Permit Requirements for Major Stationary Sources - Prevention of Significant 

Deterioration (PSD) of Air Quality," to revise the definition of"subject to regulation," as 

it applies to plantwide applicability limitations (PALs), and to revise rule 33.9 to adopt by 

reference the federal rule revision as of July 12, 2012, except the term "Administrator 

shall mean "the department of natural resources." 

The purpose of this revision was to adopt more recent federal amendments to the PSD program related 

to greenhouse gas emissions and to streamline Iowa's PSD program by providing additional 

opportunities for PALs for greenhouse gases. 

On June 23, 2014, the United States Supreme Court issued a decision addressing the application ofPSD 

permitting requirements to GHG emissions. Utility Air Regulatory Group v. Environmental Protection 

Agency, 134 S.Ct. 2427. The Supreme Court said that the EPA may not treat GHGs as an air pollutant 

for purposes of determining whether a source is a major source required to obtain a PSD permit. The 

Court also said that the EPA could continue to require that PSD permits, otherwise required based on 

emissions of pollutants other than GHGs, contain limitations on GHG emissions based on the 

application ofBest Available Control Technology (BACT). 

In accordance with the Supreme Court decision, on April10, 2015, the U.S. Court of Appeals for the 

District of Columbia Circuit (the D.C. Circuit) issued an amended judgment vacating the regulations that 

implemented Step 2 of the EPA's PSD and Title V Greenhouse Gas Tailoring Rule, but not the 

regulations that implement Step 1 of that rule. Step 1 of the Tailoring Rule covers sources that are 

required to obtain a PSD permit based on emissions of pollutants other than GHGs. Step 2 applied to 

sources that emitted only GHGs above the thresholds triggering the requirement to obtain a PSD permit. 

The amended judgment preserves, without the need for additional rulemaking by the EPA, the 

application of the BACT requirement to GHG emissions from Step 1 or "anyway" sources. With respect 

to Step 2 sources, the D.C. Circuit's amended judgment vacated the regulations at issue in the litigation, 

including 40 CFR 51.166(b )( 48)(v), "to the extent they require a stationary source to obtain a PSD 

permit if greenhouse gases are the only pollutant (i) that the source emits or has the potential to emit 

above the applicable major source thresholds, or (ii) for which there is a significant emission increase 

from a modification." 

On August 19,2015, the EPA amended its PSD and Title V regulations to remove from the Code of 

Federal Regulations portions of those regulations that the D.C. Circuit specifically identified as vacated. 

80 FR 50199. The EPA intends to further revise the PSD and Title V regulations to fully implement the 

Supreme Court and D.C. Circuit rulings in a separate rulemaking. This future rulemaking will include 

revisions to additional definitions in the PSD regulations. The EPA does not expect states to revise their 

PSD programs in anticipation of additional EPA actions to revise its PSD program rules in response to 

the court decisions. 

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on May 7, 2010 through September 15, 2011) as the aggregate group of six greenhouse gases 

that includes carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, 

and sulfur hexafluoride, shall not be subject to regulation except as provided in paragraphs 

"4" and and shall not be subject to regulation if the stationary source maintains its 

total sourcewide emissions below the GHG PAL level, meets the requirements in rule 567-

33.9(455B), and complies with the PAL permit containing the GHG PAL. 

The remainder of the definition remains the same. 

• Subrule 33.9 Plantwide applicability limitations (PALs) was revised as follows: 

This rule provides an existing major source the option of establishing a plantwide 

applicability limitation (PAL) on emissions, provided the conditions in this rule are met. 

The provision for a PAL as set forth in 40 CFR 52.21(aa) as amended through November 

29, 2005 July 12, 2012, are adopted by reference, except that the term "administrator" 

shall mean "the department of natural resources." 

IA-131 

Iowa Department ofNatural Resources 

Record of Rulemaking 

Notice of Intended Action January 2, 2008 

Public Hearing February 4, 2008 

State Effective Date 7, 2008 

Sent to EPA November 4, 2008 

Received by EPA November 18, 2008 

IA-159 

Iowa Department ofNatural Resources 

Record of Rulemaking 

Notice of Intended Action March 13, 2013 

Public Hearing April23, 2013 

State Effective Date July 17, 2013 

Sent to EPA July 17, 2013 

Received by EPA July24, 2013 

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