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Review of Federal Air Regulations

for the

Oil and Natural Gas Sector 

Public Stakeholder Meetings

Arlington, TX, August 2, 2010

Denver, CO, August 3, 2010

US Environmental Protection Agency

Office of Air and Radiation

Office of Air Quality Planning and Standards
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Overview

 Background on the Oil and Natural Gas sector

 Our regulatory tools

 Applying our tools to this sector

 Schedule for future activities

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The Oil and Natural Gas sector has 

become the focus of increasing 

public attention

 Horizontal drilling and hydraulic fracturing enable extraction of shale gas

 Gas reserves have gone from under 50 years to over 100 years

 Recent gas boom has heightened public concern (water and air impacts)

 Winter ozone exceedances in western states linked to oil and gas activity

 Oil and natural gas sector accounts for 23% of U.S. methane emissions

 Certain emissions are not addressed by existing federal air rules 
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Source: American Gas Association and EPA Natural Gas STAR Program 5

Producing Wells 

(Onshore and Offshore)

Gathering Lines

Compressor Stations

Processing Plant

Oil and Natural Gas Operations

Underground 

Storage

Transmission Lines

City Gate 

Regulators 

Meters

Regulators/Meters

Large Volume Customer

Residential Customers

Commercial Customer

Distribution Mains

Oil Refineries

(not in this sector)

LNG or Propane Plant
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What are our regulatory tools?

 New Source Performance Standards

 National Emission Standards for 

Hazardous Air Pollutants

 Control Techniques Guidelines

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New Source Performance Standards (NSPS)

 Authority provided by Congress under Section 111(b) of Clean Air Act 

(CAA)

 Primarily regulate criteria pollutants and precursors from new, 

reconstructed, and modified sources

 Ozone (via precursors VOC* and NOx*) 

 Sulfur dioxide (SO2)

 Nitrogen dioxide (NO2)

 Particulate matter

 Carbon monoxide (CO)

 Lead

 Concept -- make new facilities perform as well as the best existing 

facilities (commonly known as “best demonstrated technology”)

 Must be reviewed every 8 years to determine whether technology 

advances warrant updating the requirements 

*Volatile organic compounds (VOC) and oxides of nitrogen (NOx)
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National Emission Standards for Hazardous Air 

Pollutants (NESHAP)

 In 1990, Congress amended the CAA (section 112) to require 

EPA to control a specific list of air toxics from new and existing 

sources

 Pollutants of concern to oil and natural gas sector:

 benzene, toluene, ethylbenzene, mixed xylenes (BTEX)

 n-hexane

 Concept -- technology-based standards that require what the 

best facilities are doing

 Requires risk and technology review (RTR)

 One-time residual risk assessment 8 years after promulgation to 

determine if existing rule provides an ample margin of safety

 Technology review every 8 years to determine if technology 

advances warrant updating the requirements
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Control Techniques Guidelines (CTG)

 Authority provided under Section 182 of CAA to 

provide guidance to states for incorporation of 

control measures into state implementation 

plans (SIPs)

 Affect new and existing sources in ozone 

nonattainment areas

 Target VOC emissions (precursor to ozone 

formation)

 Establish recommendations for reasonably 

available control technology (RACT)
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What have we done so far? -- NSPS

 Subpart KKK (1985) requires VOC leak detection and repair 

(LDAR) for gas processing plants (facilities that remove 

natural gas liquids from field gas)

 Subpart LLL (1985) requires control of SO2 emissions from 

gas processing plants

 Sweetening units (remove H2S and CO2 from sour gas)

 Sulfur recovery units (recover elemental sulfur)

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What have we done so far? -- NESHAP

 Subpart HH controls air toxics from oil and natural gas 

production operations (major source rule 1999, area 

source rule 2007)

 Tanks with flash emissions (major sources only)

 Equipment leaks (major sources only)

 Glycol dehydrators (major and area sources)

 Subpart HHH controls air toxics from natural gas 

transmission and storage operations (1999)

 Glycol dehydrators (major sources only)
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Deadline Litigation

 CAA requires periodic reviews of NSPS and NESHAP

 In 2009 WildEarth Guardians and San Juan Citizens 

Alliance filed deadline suit for failure to conduct required 

reviews of the two NSPS (1985) and failure to conduct 

risk and technology reviews of the MACT rules (1999)

 Consent Decree entered 02/04/10

 Deadline for proposed action 01/31/11

 Deadline for final action 11/30/11

 In addressing these obligations, we are evaluating the 

entire range of operations
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What are we doing in our review?

 We are looking at operations across the 

entire sector

 Identifying emission sources

 Quantifying emissions

 Considering mitigation opportunities

 Analyzing environmental and economic impacts

 The next few slides show the sources of 

emissions in each segment
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venting of 

casinghead gas

flash emissions

from storage tanks

Where are the emissions?

NOTE: Shaded boxes denote emission sources 

at least partially covered by existing rules

vapor from 

truck loading produced 

water 

Ponds

land 

farming

Crude Oil

Production

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well completions 

and workovers

Where are the emissions?

NOTE: Shaded boxes denote emission sources 

at least partially covered by existing rules

reciprocating 

compressor rod 

packing

gas-driven 

pneumatic 

devices

Natural Gas

Production and

Processing

processing plant leaks

glycol dehydrators

sweetening and 

sulfur recovery units

flash emissions

from storage tanks
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leaks from 

pipelines and 

compressor 

stations

Where are the emissions?

NOTE: Shaded boxes denote emission sources 

at least partially covered by existing rules

centrifugal 

compressor seal 

oil de-gassing

gas-driven 

pneumatic 

devices

Natural Gas

Transmission

and Storage

glycol dehydrators

reciprocating 

compressor rod 

packing

storage tanks

venting of gas for 

maintenance or repair of 

pipelines and compressors
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leaks from 

unprotected steel 

mains and 

service lines

Where are the emissions?

NOTE: Shaded boxes denote emission sources 

at least partially covered by existing rules

leaks at metering 

and regulating 

stations

gas-driven 

pneumatic 

devices

Natural Gas

Distribution

pipeline blowdowns

leaks from 

pipelines and 

compressor 

stations
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Where do we go from here?

 Propose action (1/2011)

 Public comment period following proposal

 Complete reviews and take final action (11/2011)

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How can you help?

 Continue what you’re doing right now – be 

involved in the process

 In the near term -- provide information on recent 

studies that provide emissions data

 During the public comment period following 

proposal – give us constructive feedback