Comparison of Air Emission Standards for the Oil & 

Gas Industry

(Well Pad Operations, Natural Gas Compressor Stations, and Natural Gas Processing Facilities)

Pennsylvania Department of Environmental Protection, Bureau of Air Quality

5/23/2014

The Pennsylvania Department of Environmental Protection issued a General Permit, General Plan Approval and/or General Operating Permit (BAQ-GPA/GP-5) to authorize the construction, 

modification, and/or operation of natural gas compression and/or natural gas processing facilities. Plan Approval and Operating Permit Exemption Category #38 (Well Pad Operations) was amended on 

August 10, 2013.

The Center for Sustainable Shale Development (CSSD) is an independent nonprofit organization based in Pittsburgh, Pennsylvania. The Center provides a forum for a diverse group of stakeholders to 

share expertise with the common objective of developing solutions and serving as a center of excellence for shale gas development. CSSD’s mission is to support continuous improvement and 

innovative practices through performance standards and third-party certification. CSSD has developed initial performance standards for operators engaged in unconventional exploration, development, 

and gathering activities including site construction, drilling, hydraulic fracturing and production in the Appalachian Basin. These standards represent consensus on what is achievable and protective of 

human health and the environment.

Colorado Department of Public Health and Environment, Air Quality Control Commission has promulgated air emissions regulations 3, 6, & 7 (adopted 23-Feb-2014) impacting oil and gas (O&G) 

exploration and production (E&P) activities in Colorado.

EPA has promulgated New Source Performance Standards at 40 CFR Part 60, Subpart OOOO (Standards of Performance for Crude Oil and Natural Gas Production, Transmission, and Distribution).

West Virginia and Ohio have issued General Air Permits for Natural Gas Production facilities.

This document provides a comparison of the requirements in these air standards. The information highlighted in blue was compiled by CSSD.
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 1 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Well Site Exemption Category No. 381

 Requires compliance with NSPS 

requirements in 40 CFR Part 60, Subpart 

OOOO. 

 Beginning 10/15/12 - No venting allowed 

– must capture and direct flowback 

emissions to a completion combustion 

device, except in conditions that may 

result in a fire hazard or explosion. 

 Beginning on 1/1/15 – direct all pipelinequality gas during completion of 

development wells and re-completion or 

workover of any well into a pipeline for 

sales. 

 Open Flaring is only allowed under the 

following circumstances:

o used at exploration wells to 

determine whether oil and/or 

gas exists in geological 

formations or to appraise the 

physical extent, reserves and 

likely production rate of an oil or 

gas field.

o Flaring used for repair, 

maintenance, emergency or 

safety purposes.

o Flaring used for other 

operations at a wellhead or 

facility to comply with 40 CFR 

Performance Standard No. 9 

 Beginning on 1/1/14 – direct all 

pipeline-quality gas during completion 

of development wells and recompletion or workover of any well into 

a pipeline for sales. 

 No venting allowed – must be flared in 

accordance with CSSD Performance 

Standard No. 10. 

 Acceptable reasons for flaring – low 

content of flammable gas and safety 

reasons.

 Unacceptable reasons for flaring – i) 

lack of pipeline connection except for 

exploratory or extension wells; ii) 

inadequate water disposal capacity; iii) 

inadequate or lack of flowback 

equipment or operating personnel.

NSPS Subpart OOOO

 Beginning 10/15/12: 

o Must capture and direct 

flowback emissions to a 

completion combustion 

device, except in conditions 

that may result in a fire 

hazard or explosion.2

 Beginning 1/1/15:

o REC equipment required 

for all wells besides those 

classified as wildcat, 

delineation or low 

pressure.3

o Salable quality gas must be 

routed to the gas flow line 

“as soon as practicable.”4

o Emissions that cannot be 

directed to the gas flow 

must be directed to a 

completion combustion 

device (e.g., flare) with a 

continuous ignition source 

except in conditions that 

may result in a fire hazard 

or explosion.5

o General duty to safely 

maximize resource 

recovery and minimize 

releases to the atmosphere 

during flowback and 

subsequent recovery.6

Regulation Nos. 6 & 7:

 Requires compliance with NSPS 

requirements in 40 CFR Part 60, Subpart 

OOOO. 

 If a combustion device is used to control 

emissions of VOCs and other 

hydrocarbons, it shall be enclosed. 

 Alternative emissions control equipment 

shall qualify as air pollution control 

equipment, and may be used if the Division 

approves the equipment, device or 

process.

Current

 No state-specific REC 

requirements in addition to NSPS 

Subpart OOOO.

 Flaring required except for gas 

releases by a properly functioning 

relief device and gas released by 

controlled venting for testing, 

blowing down and cleaning out 

wells.7

Proposed

 Natural Gas Completion Permitby-Rule8 – requires compliance 

with NSPS Subpart OOOO.

 No state-specific REC 

requirements in addition 

to NSPS Subpart OOOO

 Compliance with NSPS 

Subpart OOOO 

requirements is required 

by General Permit G70-

A9; (however, permit is 

not required to be 

obtained prior to well 

completion activities.)

10

 

1 49 Pennsylvania’s Air Quality Permit Exemptions 

2

40 C.F.R. § 60.5375(a)

3

40 C.F.R. § 60.5375(a)

4

40 C.F.R. § 60.5375(a)(2)

5

40 C.F.R. § 60.5375(a)(3)

6

40 C.F.R. § 60.5375(a)(4)

7

Ohio Admin. Code § 1501:9-9-05(B)

8

Ohio’s Draft Natural Gas Completion Draft Permit-by-Rule
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 2 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Part 60, Subpart OOOO 

requirements.

 Enclosed combustion device including 

enclosed flare must be used for all 

permanent flaring operations at a 

wellhead or facility. These flaring 

operations will be designed and operated 

in accordance with the requirements of 40 

CFR § 60.18.

Flaring Exemption Category No. 38 11

 Flaring during completions as allowed by 

NSPS Subpart OOOO. 

Post Completion Requirements:

 Enclosed flare (Raised/elevated flares or 

engineered combustion device) must be 

used for permanent installations. 

 All permanent enclosed flaring operations 

must be designed and operated in

accordance with 40 CFR § 60.18. 

Performance Standard No. 10

 Raised/elevated flares or engineered 

combustion device with a reliable 

continuous ignition source.

 98% destruction efficiency.

 Development well: flaring no more than 

14-days (for life of well). 

 Exploratory/Extension wells: Flaring no 

more than 30-days (for life of well). 

 No visible emissions from flares except 

NSPS Subpart OOOO

 Completion combustion 

devices (e.g. flares) are 

required to have a 

continuous ignition 

source.12

Regulation No. 7:

 If a combustion device is used to control 

emissions of VOCs and other 

hydrocarbons, it shall be enclosed. 

 Have no visible emissions during normal 

operations

 Be designed so than that an observer can 

determine whether it is operating properly.

 Auto-igniters: All combustion devices used 

to control emissions of hydrocarbons must 

be equipped with and operate an autoCurrent

 Requires “properly functioning relief 

device”13

Proposed Natural Gas Completion Permitby-Rule14

 Emissions limitations for completion 

operations: 

o 34 tons/yr VOCs.

o 1.7 tons/yr NOx.

o 9.3 tons/yr CO.

o 0.82 tons/yr HAP.

 “Temporary” flaring 

allowed for 30-days 

before a permit is 

required.

15

o 20% opacity 

limitation and 

PM emissions 

limit set 

according to a 

formula

16

 General Permit G70A: 

20% opacity limitation 

 

9 WVDEP General Permit G70-A, Section 5.1

10 WVDEP Response to Public Comment #33 on General Permit G70-A

11Pennsylvania’s Air Quality Permit Exemptions 

12 40 C.F.R § 60.5375(a)(3)

13 Ohio Admin. Code § 1501:9-9-05(B)

14 Ohio’s Proposed Natural Gas Completion Permit-by-Rule

15 W. Va. Code R. § 45-6-6.1a

16 W. Va. Code R. § 45-6-4.1, 4.3
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 3 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

 Open Flaring is only allowed under the 

following circumstances:

o Flaring used at exploration wells 

to determine whether oil and/or 

gas exists in geological 

formations or to appraise the 

physical extent, reserves and 

likely production rate of an oil or 

gas field.

o Flaring used for repair, 

maintenance, emergency or 

safety purposes.

o Flaring used for other 

operations at a wellhead or 

facility to comply with 40 CFR 

Part 60, Subpart OOOO 

requirements.

 Opacity is limited to 20% or greater for an 

aggregated 3 min period in any 1 hour, 

but cannot be equal to or greater than 

60% opacity at any time.

for periods not to exceed a total of five 

minutes during any two consecutive 

hours. 

igniter as follows:

o All combustion devices installed 

on or after May 1, 2014, must be 

equipped with an operational 

auto-igniter upon installation of 

the combustion device.

o All combustion devices installed 

before May 1, 2014, must be 

equipped with an operational 

auto-igniter by or before May 1, 

2016, or after the next 

combustion device planned 

shutdown, whichever comes first.

 Alternative emissions control equipment 

shall qualify as air pollution control 

equipment, and may be used if the Division 

approves the equipment, device or 

process.

GP-12.119

Enclosed or Open Flare(s)/Combustion 

Device(s) with a maximum combined 

capacity heat input of no more than 250 

MMBtu/hr and operated at no more than 10 

MMBtu per hour combined heat input from 

all the sources vented to the combustion 

device(s), except during an emergency.

o For VOC and where applicable, 

compliance with the applicable 

control requirements of 40 CFR 

Part 60, Subpart OOOO, by having 

a designed minimum control 

efficiency of 95% for an enclosed 

flare/combustor.

o Carbon monoxide (CO) emissions 

shall not exceed 1.35 tons per 

month averaged over a 12-month 

rolling period.

o Nitrogen Oxide (NOx) emissions 

shall not exceed 0.25 ton per 

month averaged over a 12-month 

rolling period.

o Sulfur Dioxide (SO2) emissions 

shall not exceed 0.15 ton per 

month averaged over a 12-month 

rolling period.

GP-12.220

Enclosed or Open Flare(s)/Combustion 

Device(s) with a maximum combined 

capacity heat input of no more than 250 

MMBtu/hr and operated at no more than 32 

MMBtu per hour combined heat input from 

all the sources vented to the combustion 

device(s), except during an emergency.

and PM emissions limit 

set according to a 

formula.

17

 However, permit is not 

required to be obtained 

prior to well completion 

activities.

18

 

19 Ohio General Permit 12.1, Condition 4

20 Ohio General Permit 12.2, Condition 4

17 WVDEP General Permit G70-A, Section 5.1.5

18 WVDEP Response to Public Comment #33 on General Permit G70-A
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 4 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

o For VOC and where applicable, 

compliance with the applicable 

control requirements of 40 CFR 

Part 60, Subpart OOOO, by having 

a designed minimum control 

efficiency of 95% for an enclosed 

flare/combustor.

o Carbon monoxide (CO) emissions 

shall not exceed 4.32 tons per 

month averaged over a 12-month 

rolling period.

o Nitrogen Oxide (NOx) emissions 

shall not exceed 0.79 ton per 

month averaged over a 12-month 

rolling period.

o Sulfur Dioxide (SO2) emissions 

shall not exceed 0.48 ton per 

month averaged over a 12-month 

rolling period.

Diesel Nonroad 

Drilling Rig 

Engines 

 States including Pennsylvania are 

precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 89.

 Non-road engines are exempt from 

permitting requirements under Exemption 

Category No. 38.21

 All non-road engines must comply with 

federal emission standards found in 40 

CFR Part 89, Subpart B or 40 CFR Part 

1039, Subpart B, based upon the engine’s 

model year.

 Only ultra-low sulfur diesel fuel will be 

available.

Performance Standard No. 11

 Meet EPA Tier 2 standards by March 

20, 2013. 

 25% of owner/operator engine 

utilization (hp) meeting EPA Tier 4 

standards for PM by March 20, 2015. 

 75% of owner/operator engine 

utilization (hp) meeting EPA Tier 4 

standards for PM by September 24, 

2015. 

 95% of owner/operator engine 

utilization meeting EPA Tier 4 

standards for PM by September 24, 

2016. 

 Use ultra-low sulfur diesel (15ppm of 

 U.S. EPA regulates 

emissions from non-road 

diesel engines according to 

varying “tiered” levels based 

on the engine’s 

manufacturing date.22

 Starting in 2010, diesel 

produced for use in nonroad engines required to 

meet ultra-low sulfur (15 

ppm of sulfur) 

requirement.23

 States are precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 89.

 States are precluded from 

establishing any emissions 

limitations other than those 

required by 40 CFR Part 89.

 States are precluded 

from establishing 

any emissions

limitations other than 

those required by 40 

CFR Part 89.

 

21Pennsylvania’s Air Quality Permit Exemptions 

22 40 C.F.R. Part 89; 40 C.F.R. Part 1039

23 40 C.F.R. Part 80
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 5 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

sulfur) at all times.

Diesel Nonroad 

Fracturing 

Pump Engines

 States including Pennsylvania are

precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 89.

 Non-road engines are exempt from 

permitting requirements under Exemption 

Category No. 38.

 All non-road engines must comply with 

federal emission standards found in 40 

CFR Part 89, Subpart B or 40 CFR Part 

1039, Subpart B based upon the engine’s 

model year. 

 Only ultra-low sulfur diesel fuel will be 

available.

Performance Standard No. 11.1

 Meet EPA Tier 2 standards by 

March 20, 2014. 

 25% of owner/operator engine 

utilization (hp) meeting EPA Tier 4 

standards for PM by September 

24, 2015/ March 20, 2016. 

 75% of owner/operator engine 

utilization (hp) meeting EPA Tier 4 

standards for PM by September 

24, 2016. 

 95% of owner/operator engine 

utilization meeting EPA Tier 4 

standards for PM by September 

24, 2017. 

 Use ultra-low sulfur diesel (15ppm 

of sulfur) at all times. 

 U.S. EPA regulates 

emissions from non-road 

diesel engines according to 

varying “tiered” levels based 

on the engine’s 

manufacturing date24

 Starting in 2010, diesel 

produced for use in nonroad engines required to 

meet ultra-low sulfur (15 

ppm of sulfur) 

requirement.25

 States are precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 89.

 States are precluded from

establishing any emissions 

limitations other than those 

required by 40 CFR Part 89.

 States are precluded 

from establishing 

any emissions 

limitations other than 

those required by 40 

CFR Part 89.

Diesel HeavyDuty Vehicle 

Fracturing 

Pump Engines

 States including Pennsylvania are 

precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 86.

 Heavy duty vehicle engines are exempt 

from permitting requirements under 

Exemption Category No. 38.

 All Heavy Duty vehicle engines must 

comply with federal emission standards 

found in 40 CFR Part 86.

 Only ultra-low sulfur diesel fuel will be 

available.

Performance Standard No. 11.2

 50% of engines meeting EPA 2007 

and Later Model Year Highway HeavyDuty Vehicles and Engines emissions 

standards for PM by September24, 

2017. 

 80% of engines meeting EPA 2007 

and Later Model Year Highway HeavyDuty Vehicles and Engines emissions 

standards for PM by September 24, 

2014.

 Use ultra-low sulfur diesel (15ppm of 

sulfur) at all times.

 U.S. EPA regulates engine 

emissions from highway 

heavy-duty vehicles based 

on the vehicle’s model year. 

 Starting in 2006, highway 

diesel fuel required to meet 

ultra-low sulfur (15 ppm of 

sulfur) requirement.

 States are precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 89.

 States are precluded from 

establishing any emissions 

limitations other than those 

required by 40 CFR Part 89.

 States are precluded 

from establishing 

any emissions 

limitations other than 

those required by 40 

CFR Part 89.

 

24 40 C.F.R. Part 89; 40 C.F.R. Part 1039

25 40 C.F.R. Part 80
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 6 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Existing 

Compressor 

Engines 

Previous Exemption Category No. 38

 Existing compressor engines (those 

installed prior to August 10, 2013) –

exempt from any permitting or emission 

limitation requirements if less than 100 

hp. 

Previous GP-5

 Prior to February 2013 - existing 

compressor engines greater than or equal 

to 100 hp and less than 1500 hp were 

subject to the previous GP-5 emissions 

limitations:

o 2.0 g/hp-hr NOx.

o 2.0 g/hp-hr CO.

o 2.0 g/hp-hr VOCs.

 Emission test results indicate that the 

existing compressor engines authorized under 

the previous GP-5 are generally meeting the 

CCSD performance standard of 1.5 g/bhp-hr 

of NOx.

Performance Standard No. 12

 By March 20, 2014 – 1.5 g/hphr NOx 

emission limitation for existing 

compressor engines greater than 100 

hp. 

o CO – None

o VOC – None

NSPS Subpart JJJJ (Standards of 

Performance for Stationary Spark 

Ignition Internal Combustion Engines)

 Applies to constructed, 

reconstructed, and modified 

engines after June 12, 

2006.26

 Emissions limitations for 

engines manufactured 

between 2007/2008 and 

2010/2011 greater than 100 

hp:27

o 2.0 g/hp-hr for 

NOx.

o 4.0 g/hp-hr for 

CO.

o 1.0 g/hp-hr for 

VOCs.

 Compressor engines are 

also subject to the National 

Emission Standards for 

Hazardous Air Pollutants 

(NESHAP) for Stationary 

Reciprocating Internal 

Combustion Engines (RICE) 

at 40 C.F.R. 63, Subpart 

ZZZZ (i.e., the “RICE 

MACT”)28

Existing Natural Gas Fired Reciprocating Internal 

Combustion Engines: 

Rich Burn Reciprocating Internal Combustion 

Engines:

 Rich Burn Engines greater than 500 

horsepower, constructed or modified 

before February 1, 2009 - shall install 

NSCR and an air fuel controller by July 1, 

2010.

 Any rich burn reciprocating internal 

combustion engine constructed or modified 

before February 1, 2009, for which the 

owner or operator demonstrates to the 

Division that retrofit technology cannot be 

installed at a cost of less than $ 5,000 per 

ton of combined volatile organic compound 

and nitrogen oxides emission reductions 

(this value shall be adjusted for future 

applications according to the current day 

consumer price index) is exempt complying 

with Section XVII.E.3.a. 

Lean Burn Reciprocating Internal Combustion 

Engines:

 All lean burn reciprocating internal 

combustion engines rated greater than 500 

horsepower - install and operate an 

oxidation catalyst by July 1, 2010.

 Any lean burn reciprocating internal 

combustion engine constructed or modified 

before February 1, 2009, for which the 

owner or operator demonstrates to the 

Division that retrofit technology cannot be 

installed at a cost of less than $ 5,000 per 

ton of volatile organic compound emission 

reduction (this value shall be adjusted for 

future applications according to the current 

Natural Gas Compressor 

Station General Permit 

Number G33-A29

Engines over 100 HP -

compliance with NSPS 

Subpart JJJJ.

 

26 40 C.F.R. § 60.4230

27 40 C.F.R. Part 60, Subpart JJJJ, Table 1

28 40 C.F.R. Part 63, Subpart ZZZZ

29 WVDEP General Permit G33-A, Section 6.0
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 7 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

day consumer price index) is exempt from 

complying with the requirement to install an 

oxidation catalyst.

“New” LeanBurn 

Compressor 

Engines 

Exemption Category No. 38 (Compressor Engines 

at the Wellpad)30

 Lean-Burn compressor engines at the 

wellpad (those installed on or after August 

10, 2013) are exempt from permitting 

requirements provided that: 

o NOx emissions from stationary 

internal combustion engines at 

the wells, and wellheads are 

less than 100 lbs/hr, 1000 

lbs/day, 2.75 tons per ozone 

season (May 1 to September 

30); and 6.6. tons per year on a 

12-month rolling basis.

o VOC emissions from facility is 

less than 2.7 tpy, VOC from 

facility is exempted. If the 

VOCs include HAPs, the HAP 

exemption criteria in this 

paragraph will be met. 

Combined HAP emissions at 

the facility less than 1000 lbs of 

a single HAP or one ton of a 

combination of HAPs in any 

consecutive 12-month period.

o If the exemption criteria cannot 

be met, then a case-by-case 

plan approval is required.

GP-5 (Compressor Engines at Natural Gas 

Compression and/or Processing Facilities) (Feb. 

2013)

 The facility emissions are limited to nonmajor emission thresholds. (Synthetic 

Minor) 

Performance Standard No. 12.1

 Emissions limitations for new, 

purchased, replacement, 

reconstructed, or relocated lean-burn 

engines greater than 100 hp:

o 0.5 g/hp-hr NOx. 

o 2.0 g/hp-hr CO.

o 0.7 g/hp-hr VOCs.

o Formaldehyde – None

o HAPS – No facility wide limit

NSPS Subpart JJJJ (Standards of 

Performance for Stationary Spark 

Ignition Internal Combustion Engines)

 Emissions limitations for engines 

manufactured on or after 

2010/2011 greater than 100 hp 

engine models (depending on 

engine size)31:

o 1.0 g/hp-hr for NOx.

o 2.0 g/hp-hr for CO.

o 0.7 g/hp-hr for VOCs.

Compressor engines are also subject 

to the National Emission Standards for 

Hazardous Air Pollutants (NESHAP) 

for Stationary Reciprocating Internal 

Combustion Engines (RICE) at 40 

C.F.R. 63, Subpart ZZZZ (i.e., the 

“RICE MACT”)32

 No emission standards for engines rated 

less than 100 HP

Regulation No. 7:

 Actual emissions from natural gas fired 

reciprocating internal combustion engines 

shall not exceed the emission performance 

standards in table below as expressed in 

units of grams per horsepower-hour (g/hphr)

Maximum 

Engine 

HP

Construction 

or 

Relocation 

Date 

Emission 

Standards is g/hphr

NOx CO VOC

< 100 HP Any NA NA NA

≥100 HP

and < 

500 HP

On or after 

January 1, 

2008

2.0 4.0 1.0

On or after 

January 1, 

2011

1.0 2.0 0.7

≥500 Hp On or after July 

1, 2007

2.0 4.0 1.0

On or after July 

1, 2010

1.0 2.0 0.7

o Formaldehyde – None

Oil and Gas Well-Site Production 

Operations, General Permit 12

 Engines must comply with NSPS 

Subpart JJJJ standards. 

 Specific emissions limitations: 

o 20% opacity, 6-min average.

o Particulate Emissions (PE):

0.310 lb/MMBtu for engines ≤ 600 

hp.

0.062 lb/MMBtu for engines > 600 

hp.

o 2.6 tons of SO2/year.

 Total combined engine power less than 

or equal to 1,300 hp:

o 2.0 g/hp-hr NOx or 160 ppmvd at 

15% O2 for engines ≥ 100 hp. 

o 4.0 g/hp-hr CO or 540 ppmvd at 

15% O2 for engines ≥ 100 hp. 

o 1.0 g/hp-hr VOCs or 86 ppmvd at 

15% O2 for engines ≥ 100 hp.

 Total combined engine power greater 

than 1,300 hp: 

o 1.0 g/hp-hr NOx /or 82 ppmvd at 

15% O2 for engines ≥ 100 hp.

o 2.0 g/hp-hr CO/or 270 ppmvd at 

15% O2 for engines ≥ 100 hp.

Natural Gas Production 

Facility Class II General 

Permit G70-A

Requires compliance with 

NSPS Subpart JJJJ.

33

 

30 Pennsylvania’s Air Quality Permit Exemptions 

31 40 C.F.R. Part 60, Subpart JJJJ, Table 1

32 40 C.F.R. Part 63, Subpart ZZZZ

33 WVDEP General Permit G70-A, Section 13
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 8 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

 Natural gas fired lean burn less than 100 

hp 

o 2.0 g/hp-hr for NOx. 

o 2.0 g/hp-hr for CO. 

 Natural gas lean burn greater than 100 hp 

and less than or equal to 500 hp 

o 1.0 g/hp-hr for NOx.

o 2.0 g/hp-hr for CO.

o 0.7 g/hp-hr for nonmethane/non-ethane 

hydrocarbons (except 

formaldehyde).

 Natural gas lean burn greater than 500 hp 

o 0.5 g/hp-hr for NOx. 

o 93% reduction for CO or 

47ppm@15% oxygen.

o 0.25 g/hp-hr for non-methane/nonethane hydrocarbons (except 

formaldehyde). 

o 0.05 g/hp-hr for formaldehyde.

o 0.7 g/hp-hr VOCs or 60 ppmvd at 

15% O2 for engines ≥ 100 hp.

“New” RichBurn 

Compressor 

Engines 

Exemption Category No. 38 (Compressor Engines 

at the Wellpad)34

 Rich Burn compressor engines at the 

wellpad (those installed on or after August 

10, 2013) exempt from permitting where:

o NOX emissions from stationary 

internal combustion engines at 

the wells, and wellheads are 

less than 100 lbs/hr, 1000 

lbs/day, 2.75 tons per ozone 

season (May 1 to September 

30); and 6.6 tons per year on a 

12-month rolling basis. 

o VOC emissions less than 2.7 

tpy, VOCs from facility are 

exempted. If the VOCs include 

HAPs, the HAP exemption 

criteria in this paragraph will be 

Performance Standard No. 12.2

 Emissions limitations for new, 

purchased, replacement, 

reconstructed, or relocated rich-burn 

engines greater than 100 hp:

o 0.3 g/hp-hr NOx.

o 2.0 g/hp-hr CO.

o 0.7 g/hp-hr VOCSs. 

o Formaldehyde - None

NSPS Subpart JJJJ (Standards of 

Performance for Stationary Spark 

Ignition Internal Combustion Engines)

 Emissions limitations for engines 

manufactured on or after 2010/2011 

greater than 100 hp engine models 

(depending on engine size):35

o 1.0 g/hp-hr for NOx.

o 2.0 g/hp-hr for CO.

o 0.7 g/hp-hr for VOCs.

Compressor engines are also subject 

to the National Emission Standards 

for Hazardous Air Pollutants 

(NESHAP) for Stationary 

Reciprocating Internal Combustion 

Engines (RICE) at 40 C.F.R. 63, 

Subpart ZZZZ (i.e., the “RICE 

Regulation No. 7:

 Actual emissions from natural gas fired 

reciprocating internal combustion engines 

shall not exceed the emission performance 

standards in table below as expressed in 

units of grams per horsepower-hour (g/hphr)

Maximum 

Engine 

HP

Construction 

or 

Relocation 

Date 

Emission 

Standards is g/hphr

NOx CO VOC

< 100 HP Any NA NA NA

≥100 HP

and < 

500 HP

On or after 

January 1, 

2008

2.0 4.0 1.0

Oil and Gas Well-Site Production 

Operations, General Permit 12

Engines must comply with NSPS Subpart 

JJJJ standards.37

 Specific emissions limitations:

38

o 20% opacity, 6-min average.

o Particulate Emissions (PE):

 0.310 lb/MMBtu for engines ≤ 600 

hp.

 0.062 lb/MMBtu for engines > 600 

hp.

o 2.6 tons of SO2/year.

o Total engine power less than or equal 

to 1,300 hp: 

Natural Gas Production 

Facility Class II General 

Permit G70-A

Compliance with NSPS 

Subpart JJJJ.

40

 

34 Pennsylvania’s Air Quality Permit Exemptions 

35 40 C.F.R. Part 60, Subpart JJJJ, Table 1
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 9 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

met. Combined HAP emissions 

at the facility less than 1000 lbs 

of a single HAP or one ton of a 

combination of HAPs in any 

consecutive 12-month period.

o If the exemption criteria cannot 

be met, then a case-by-case 

plan approval is required.

Coverage under GP-5 (Rich-Burn Compressor 

Engines at Natural Gas Compression and/or 

Processing Facilities) (Feb. 2013)

 The facility emissions are limited to nonmajor emission thresholds. (Synthetic 

Minor) 

 Natural gas fired rich burn engines less 

than or equal to 100 hp: 

 2.0 g/hp-hr NOx.

 2.0 g/hp-hr CO.

 Natural gas rich burn engines greater 

than 100 hp and less than or equal to 500 

hp: 

 0.25 g/hp-hr NOx.

 0.30 g/hp-hr CO;

 0.2 g/hp-hr for non-methane/non-ethane 

hydrocarbons (except formaldehyde).

 Natural gas rich burn engines greater 

than 500 hp: 

 0.20 g/hp-hr NOx. 

 0.30 g/hp-hr CO.

 0.20 g/hp-hr for non-methane/non-ethane 

hydrocarbons (except formaldehyde).

 76% reduction for formaldehyde or 2.7 

ppmvd @ 15% oxygen

MACT”)36 On or after 

January 1, 

2011

1.0 2.0 0.7

≥500 Hp On or after July 

1, 2007

2.0 4.0 1.0

On or after July 

1, 2010

1.0 2.0 0.7

o Formaldehyde - None

 2.0 g/hp-hr NOx or 160 ppmvd at 

15% O2 for engines ≥ 100 hp. 

 4.0 g/hp-hr CO or 540 ppmvd at 

15% O2 for engines ≥ 100 hp. 

 1.0 g/hp-hr VOCs or 86 ppmvd at 

15% O2 for engines ≥ 100 hp.

o Total engine power greater than 1,300 

hp:39

 1.0 g/hp-hr NOx /or 82 ppmvd at 

15% O2 for engines ≥ 100 hp.

 2.0 g/hp-hr CO/or 270 ppmvd at 

15% O2 for engines ≥ 100 hp.

 0.7 g/hp-hr VOCs or 60 ppmvd at 

15% O2 for engines ≥ 100 hp.

 

37 Ohio GP-12, at pp. 12-14

38 Ohio GP-12, at pp. 12-14

40 WVDEP General Permit G70-A, Section 13

36 40 C.F.R. Part 63, Subpart ZZZZ

39 The total combined total engine horsepower must also be no more than 1,800 hp for the site in order to qualify for Ohio’s GP-12. See Ohio GP-12, at pp. 12. Additionally, where the total combined engine power exceeds 1,300 hp the engines must have a manufacturing date of no earlier than January 1, 

2011 for engines less than 500 HP or no earlier than July 1, 2010 for engines 500 hp or greater. Id. 
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 10 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Storage Vessels Exemption Category No. 3841:

 Storage vessels/storage tanks at the well 

pad are exempt from permit requirements 

if they are equipped with VOC emission 

controls achieving emission reduction of 

95% or greater.

 Storage tanks at the well pad can qualify 

for the exemption if combined VOC 

emissions from all the sources at the 

facility are less than 2.7 tons on a 12-

month rolling basis. Combined HAP 

emissions at the facility must be less than 

1000 lbs of a single HAP or one ton of a 

combination of HAPs in any consecutive 

12-month period in order to qualify for the 

exemption. If the VOCs emissions 

include HAPs, this HAP exemption criteria 

is met. 

 No de minimis emission threshold per 

tank as allowed in NSPS Subpart OOOO 

(i.e., must reduce storage tank/storage 

vessel VOC emissions by 95% if 

combined VOC emissions from storage 

vessels/storage tanks are above 2.7 tpy in 

order to qualify for exemption).

 Compliance with above criteria ensures 

compliance with NSPS Subpart OOOO.

GP-5

 The owner or operator of each storage 

vessel / storage tank shall also comply 

with the applicable requirements specified 

in 40 CFR Part 60, Subparts Kb and 

OOOO and 40 CFR Part 63, Subpart HH 

(relating to national emission standards 

Performance Standard No. 13

 By October 15, 2013 – all existing or 

new individual storage vessels at the 

wellpad with VOC emissions equal to 

or greater than 6 tpy must install 

controls to achieve at least a 95% 

reduction in VOC emissions.

NSPS Subpart OOOO

 “New” Group 1 storage vessels 

(constructed, modified, or 

reconstructed after August 23, 2011 

and before April 12, 2013) that have 

potential VOC emissions equal to or 

greater than 6 tons per year (tpy) -

at least a 95% reduction in VOC 

emissions by April 15, 2015.42

 “New” Group 2 storage vessels 

(constructed, modified, or 

reconstructed after April 12, 2013) 

that have potential VOC emissions 

equal to or greater than 6 tons per 

year (tpy) - at least a 95% reduction 

in VOC emissions by April 15, 2014 

or within 60-days of startup 

(whichever is later).43

 6 tpy VOC determination may take 

into account enforceable limits in an 

operating permit or other 

requirement established under a 

Federal, State, local or tribal 

authority.44

 Emissions from a storage vessel 

that are recovered and routed to a 

process through a vapor recovery 

unit (VRU) can be excluded from 

the 6 tpy VOC determination 

provided certain requirements are 

met.45

 Control devices (installed to achieve 

the 95% reduction in VOC 

emissions discussed above) may be 

removed if emissions from the 

storage vessel have been below 4 

tpy on an uncontrolled basis for 12 

Regulation No. 7:

 Construction permits are now required for 

all crude oil storage tanks (previously, 

tanks with capacity < 40,000 gallons were 

exempt)

 Operating permits are now required for all 

crude oil storage tanks (previously, tanks 

with capacity < 40,000 gallons were 

exempt)

 For tanks projected to have > 1.5 tons 

VOC emissions in first 90 days of operation

o Emissions controls must be 

installed at date of first operation 

and must have 95% (98% if 

combustion device used) 

efficiency

o Controls can be removed after 

90 days if VOC emissions are 

projected to be <6 tons per year

 Storage tank controls after 90 days:

 For tanks with VOC emissions less than 20 

TPY and equal to or greater than 6 TPY –

95% control efficiency (98% if a 

combustion device is used).

 For tanks with VOC emissions greater than 

20 TPY – 95% control efficiency.

 AVO inspections of tanks and associated 

equipment as frequent as every 7 days and 

at least every 31 days.

Oil and Gas Well-Site Production 

Operations, General Permit 12

 Total VOC emissions from all tanks 

combined at the site (including breathing 

losses, tank working losses, flash losses 

and truck loading losses) may not exceed 

51.3 tons per rolling 12-month period.

48

Natural Gas Production 

Facility Class II General 

Permit G70-A

 Requires compliance with 

NSPS Subpart OOOO49

 

41 Pennsylvania’s Air Quality Permit Exemptions 

42 40 C.F.R. § 60.5395(b)

43 40 C.F.R. § 60.5395(c)

44 40 C.F.R. § 60.5365(e)

45 40 C.F.R. § 60.5365(e)
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 11 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

for hazardous Air pollutants from oil and 

natural gas production facilities).

 In accordance with 25 Pa. Code §§ 127.1 

and 127.12(a)(5), the owner or operator of 

each storage tank with a capacity greater 

than 40,000 gallons shall also comply with 

the requirements specified in 25 Pa. Code 

§ 129.56. These storage tanks shall be 

equipped with of the following vapor loss 

control devices:

o An external or internal floating 

roof

o A vapor recovery system

 In accordance with 25 Pa. Code §§ 127.1 

and 127.12(a) (5), the owner or operator 

of each storage tank with a capacity less 

than or equal to 40,000 gallons shall also 

comply with the requirements in 25 Pa. 

Code § 129.57.

 These storage tanks shall be equipped 

with pressure relief valves.

consecutive months.46

 Control device must be reinstalled: 

(1) if a well feeding the storage 

vessel undergoes fracturing or 

refracturing; or (2) the monthly 

emissions from the uncontrolled 

storage vessel increase to 4 tpy or 

greater.47

 Storage Tank Emission Management 

(STEM) plan and inspections for tanks with 

non-stabilized liquids as follows:

Uncontrolled

VOC Emissions

(tpy)

AIMM (Approved 

Instrument Monitoring 

Method)

Inspection

Frequency

>6 and <12 Annually

>12 and <50 Quarterly

> 50 Monthly

Reciprocating 

Compressors

GP-5/ NSPS Subpart OOOO

 “New reciprocating compressors (those 

installed after August 23, 2011) – change 

rod packing either every 26,000 hours of 

operation or every 36 months as well as 

new reciprocating compressors. 50

 Reciprocating compressors located at a 

well site or an adjacent well site and 

Performance Standard No. 14.1

 Change rod packing at all reciprocating 

compressors (both existing and new), 

including those at the wellhead, either every 

26,000 hours of operation or after 36 

months. 

NSPS Subpart OOOO

 “New” reciprocating compressors 

(those installed after August 23, 

2011) – change rod packing either 

every 26,000 hours of operation or 

every 36 months as well as new 

reciprocating compressors.52

 Reciprocating compressors located 

at a well site or an adjacent well site 

Regulation 6:

 Federal Register regulations adopted by 

reference: Subpart OOOO, Standards of 

Performance for Crude Oil and Natural 

Gas Production, Transmission and 

Distribution (40 CFR Part 60, Subpart 

OOOOO, 01-Jul-2012 as amended by 78 

Fed. Reg. 58416 on 23-Sep-2013).

 NSPS OOOO applies to NG wells, storage 

 No state-specific requirements.

 No state-specific 

requirements.

 

48 Ohio GP-12, at p. 41 

49 WVDEP General Permit G70-A, Section 12.1

46 40 C.F.R. § 60.5395(d)(2)

47 40 C.F.R. § 60.5395(d)(2)

50 40 C.F.R. §60.5385(a) 
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 12 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

servicing more than one well site are 

excluded from this requirement. 51

and servicing more than one well 

site are excluded from this 

requirement.53

vessels, centrifugal compressors with wet 

seals, reciprocating compressors, 

pneumatic controllers, leaks and leaking 

components at gas plants, sweetening 

units, and NG well green completion 

provisions.

 Affects all facilities regardless of emissions 

levels.

Pneumatic 

Controllers

GP-5/ NSPS Subpart OOOO

 “New” pneumatic controllers (those 

constructed (installed), modified or 

reconstructed on or after October 15, 

2013) located between the wellhead and 

a natural gas processing plant: bleed rate 

of 6.0 scfh or less.54

 Exception to 6.0 scfh bleed rate – where 

use of a greater bleed rate is required 

based on functional needs, including 

response time, safety and positive 

actuation. 55

 The owner or operator of pneumatic 

controllers shall also comply with the 

applicable requirements specified in 40 

CFR Part 60, Subpart OOOO.

Performance Standard No. 14.2

 By October 15, 2013, pneumatic 

controllers (both existing and new):

o Low – bleed, with a natural 

gas bleed rate limit of 6.0 

scfh or less.

o Zero bleed when electricity 

(3-phase electrical power) is 

on-site.

NSPS Subpart OOOO

 “New” pneumatic controllers 

(those constructed 

(installed), modified or 

reconstructed on or after 

October 15, 2013) located 

between the wellhead and a 

natural gas processing 

plant: bleed rate of 6.0 scfh 

or less.56

 Exception to 6.0 scfh bleed 

rate – where use of a 

greater bleed rate is 

required based on functional 

needs, including response 

time, safety and positive 

actuation.57

Regulation No. 7:

 Controllers placed in service on or after 01-

May-2014 must

o Emit in an amount less than or 

equal to a low-bleed controller.

o Utilize no-bleed controller where 

on-site electrical grid power is 

accessible.

 High-bleed controllers in service prior to 

01-May-2014 must be replaced or 

retrofitted such that emissions are less 

than or equal to a low-bleed controller.

 All high-bleed controllers that must remain 

in service must obtain State approval.

 Beginning 01-May-2015

o High-bleed controllers must be 

tagged, and

o Must be inspected monthly with 

attendant maintenance to 

minimize emissions

 No state-specific requirements.

 Proposed revisions to Ohio’s Oil and Gas 

Well-Site Production Operations, General 

Permit 12 require compliance with Subpart 

OOOO requirements for pneumatic 

controllers.

Natural Gas Production 

Facility Class II General 

Permit G70-A

 Requires 

compliance with 

NSPS Subpart 

OOOO requirements 

for pneumatic 

controllers.

58

 

52 40 C.F.R. § 60.5385(a)

51 40 C.F.R. §60.5365(c)

53 40 C.F.R. § 60.5365(c)

54 40 C.F.R. §60.5390(c)(1) 

55 40 C.F.R. § 60.5390(a) 

56 40 C.F.R. § 60.5390(c)(1)

57 40 C.F.R. § 60.5390(a)

58 WVDEP General Permit G70-A, Section 8
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 13 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Centrifugal 

Compressors

GP-5 -Natural Gas Compression and/or Processing 

Facilities 

 Compliance with NSPS Subpart OOOO 

requirements for centrifugal 

compressors.59

o Reduce VOC emissions from 

each centrifugal compressor 

wet seal fluid degassing system 

by 95.0 percent or greater. 

 If a control device is used to reduce 

emissions, you must equip the wet seal 

fluid degassing system with a cover that 

meets the requirements of §60.5411(b), 

that is connected through a closed vent 

system that meets the requirements of 

§60.5411(a) and routed to a control 

device that meets the conditions specified 

in §60.5412(a), (b) and (c). As an 

alternative to routing the closed vent 

system to a control device, you may route 

the closed vent system to a process.

Performance Standard No. 14.3

 New centrifugal compressors may not 

contain wet oil seals. 

 Replace worn out wet seals on existing 

centrifugal compressors with dry seals.

NSPS Subpart OOOO

 For centrifugal compressors 

installed after August 23, 2011 -

must reduce VOC emissions from 

each centrifugal compressor wet 

seal fluid degassing system by 95 % 

or greater.60

o If a control device is used to 

reduce emissions, must equip 

the wet seal fluid degassing 

system with a cover that 

meets the requirements of 40 

CFR §60.5411(b), that is 

connected through a closed 

vent system that meets the 

requirements of 40 CFR 

§60.5411(a) and routed to a 

control device that meets the 

conditions specified in 40 

CFR §60.5412(a), (b) and (c). 

As an alternative to routing 

the closed vent system to a 

control device, may route the 

closed vent system to a 

process.

 Not applicable to centrifugal 

compressors located at a well site 

or at an adjacent well site and 

servicing more than one well site.61

Regulation 6:

 NSPS OOOO applies to NG wells, storage 

vessels, centrifugal compressors with wet 

seals, reciprocating compressors,

pneumatic controllers, leaks and leaking 

components at gas plants, sweetening 

units, and NG well green completion 

provisions.

 No state-specific requirements.  No state-specific 

requirements.

LDAR Exemption Category No. 3862

 Perform a leak detection and repair 

(LDAR) program within 60 days after the 

well is put into production and annually 

thereafter.

o Use of optical gas imaging 

Performance Standard No. 14.4

 By March 20, 2014 – implement a 

directed inspection and maintenance 

program (DI&M) for equipment leaks 

from all existing and new valves, pump 

seals, flanges, compressor seals, 

NSPS Subpart OOOO

 Cover and closed vent inspections 

for “new” storage vessels with 

potential to emit VOC emissions 

equal to or greater than 6 tpy.63

o Monthly olfactory, visual and 

Well Production Facilities:

 AIMM (Approved Instrument Monitoring 

Method) inspection must be initiated 15 to 

30 days after unit commences operation 

for units constructed on or after 15-Oct2014

Oil and Gas Well-Site Production 

Operations, General Permit 12.1 & 12.2

 Leaks shall be detected by the use 

of either a “Forward Looking Infra 

Red” (FLIR) camera or an analyzer 

meeting U.S. EPA Method 2164.

G70-A

 Compliance with NSPS 

Subpart OOOO 

inspection requirements 

for storage vessels.

65

 

59 Pennsylvania’s GP-5 -Natural Gas Compression and/or Processing Facilities, Section D 

60 40 C.F.R. § 60.5380(a)

61 40 C.F.R. § 60.5365(b)

62 Pennsylvania’s Air Quality Permit Exemptions

63 40 C.F.R. § 60.5416(c)

64 Ohio GP-12.1 & 12.2
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 14 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

camera (such as FLIR) or gas 

leak detector.

o Conduct on valves, flanges, 

connectors, storage 

vessels/storage tanks, and 

compressor seals.

o If leak is discovered – repair 

within in 15 days unless facility 

shutdown is required or 

ordering replacement parts are 

necessary for the repair.

 Upon written request documenting 

justification – DEP may grant extension 

for leak detection deadlines or repairs. 

 A leak is considered repaired if one of the 

following can be demonstrated:

o No detectable emissions 

consistent with EPA Method 21 

specified in 40 CFR Part 60, 

Appendix A

o A concentration of 2.5% 

methane or less using a gas 

leak detector and a VOC 

concentration of 500 ppm or 

less

o No visible leak image when 

using an optical gas imaging 

camera

o No bubbling at leak interface 

using a soap solution bubble 

test specified in EPA Method 21

o Any other method approved in 

writing by the Department

pressure relief valves, open-ended 

lines, tanks and other process and 

operation components that result in 

fugitive emissions.

o Monitored by a weekly 

visual, auditory, and olfactory 

check. 

o Yearly mechanical or 

instrument check to detect 

leaks. 

o Repair detected significant 

leaks in a timely manner. 

o No leak repair quantification

o No FLIR or gas detector

auditory inspections for defects 

that could result in air 

emissions.

o If leak detected:

 Within 5 days – make first 

repair attempt.

 Complete repair within 30 

days.

 Apply grease to 

deteriorating or cracked 

gaskets to improve the seal 

while awaiting repair.

Delay permissible if repair requires 

shutdown or if emissions during repair 

would be greater than delay of repair 

until shutdown.

 AIMM inspection must be initiated by the 

phase-in schedule for units constructed 

before 15-Oct-2014

 AIMM inspections will continue as follows 

based on uncontrolled VOC emissions 

from the highest emitting storage tank or 

controlled VOC emissions from all 

permanent equipment:

Well Production Facilities without Storage Tanks:

Well 

Production

Facilities 

WITHOUT

Storage Tanks 

(tpy)

AIMM

Inspection

Frequency

AVO

Inspection

Frequency

0 < x < 6 One time Monthly

6 < x < 12 Annually Monthly

12 < x < 20 Quarterly Monthly

x > 20 Monthly Monthly

Well Production Facilities with Storage Tanks:

Well 

Production

Facilities 

WITH

Storage Tanks 

(tpy)

AIMM

Inspection

Frequency

AVO

Inspection

Frequency

0 < x < 6 One time Monthly

6 < x < 12 Annually Monthly

12 < x < 50 Quarterly Monthly

x > 50 Monthly Monthly

Natural Gas Compressor Stations:

 AIMM inspections schedule for units 

constructed on or after 01-Jan-2015

o With fugitive VOC emissions < 

50 tons, must begin < 90 days

o With fugitive VOC emissions > 

 2Initial monitoring within 90 days 

of startup and quarterly thereafter 

for a period of four consecutive 

quarters (1 year).

 If following the initial four 

consecutive quarters, less than or 

equal to 2.0% of the ancillary 

equipment are determined to be 

leaking during the most recent 

quarterly monitoring event, then 

the frequency of monitoring can be 

reduced to semi-annual.

 If following two consecutive semiannual periods, less than 2.0% of 

the ancillary equipment are 

determined to be leaking during 

the most recent semi-annual 

monitoring event, then the 

frequency of the monitoring can be 

reduced to annual.

 If more than or equal to 2.0% of 

the ancillary equipment are 

determined to be leaking during 

any one of the semi-annual or 

annual monitoring events, then the 

frequency of monitoring shall be 

returned to quarterly. 

 The program shall require the first 

attempt at repair within five (5) 

calendar days of determining a 

leak.

 The program shall require that the 

leaking component is repaired 

within 30 calendar days after the 

leak is detected.

 Leaks shall be measured by 

utilizing U.S. EPA Method 21 (40 

CFR Part 60, Appendix A). All 

potential leak interfaces shall be 

traversed as close to the interface 

 

65 WVDEP General Permit G70-A, Section 12
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 15 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

GP-5 LDAR Program

 At a minimum, on a monthly basis 

perform a leak detection and repair 

program that includes audible, visual, and 

olfactory (“AVO”) inspections.

 Within 180 days after initial startup and at 

a minimum on a quarterly basis, use 

forward looking infrared (“FLIR”) cameras 

or other leak detection monitoring devices 

approved by the Department for the 

detection of fugitive leaks. The 

Department may grant an extension for 

the use of FLIR camera upon receiving a 

written request that documents the 

justification.

 Repair detected leaks as soon as 

possible but no later than 15 days after 

the leak is detected.

 Records must be kept for a period of 5

years.

 Operators are required to submit annual 

reports to the DEP.

50 tons, must begin < 30 days

 AIMM inspections will continue as follows:

Fugitive VOC 

Emissions (tpy)

Inspection Frequency

>0 and < 12 Annually

> 12 and < 50 Quarterly

> 50 Monthly

Repairing Leaks:

 Quantitative AIMM (EPA Method 21 or 

other Division approved method)

o Units constructed on or after 01-

May-2014, a leak is anything > 

500 ppm

o Units constructed before 01-May2014, a leak is anything > 2,000 

ppm

 For infra-red camera or AVO, a leak is any 

detectable emission not associated with 

normal operation.

 Leaks must be repaired within

o 5 days after discovery unless 

parts are unavailable, equipment 

requires shutdown, or other good 

cause

o 15 days if parts need to be 

ordered

o If shutdown required, leak must 

be repaired at next scheduled 

shutdown

o If other good cause, leak must be 

repaired within 15 days good 

as possible. The arithmetic 

difference between the maximum 

concentration indicated by the 

instrument and the background 

level is compared with 500 ppm or 

10,000 ppm (as applicable) for 

determining compliance.

 A component is considered to be 

leaking if the instrument reading is 

equal to or greater than 500 ppm 

or 10,000 ppm depending on the 

component.
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 16 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

cause ceases

o Equipment must be re-monitored 

within 15 days of repair

o Records must be kept for a 

period of 2 years

o Operators are required to submit 

annual reports to the State.

Well-bore freezeup emissions  Facility VOC emissions exceeding 2.7 tpy may 

require Plan Approval (case-by-case BAT).

Performance Standard No. 14.5

 Eliminate VOC emissions associated with 

the prevention of well-bore freeze-up (only 

de minimis emissions are permitted).

 None.  None.  None.

Blowdown 

emissions  Facility VOC emissions exceeding 2.7 tpy may 

require Plan Approval (case-by-case BAT).

Performance Standard No. 14.6

 Existing and new compressors are required 

to be pressurized when they are off-line for 

operational reasons in order to reduce 

blowdown emissions.

 None.  None.  None.

Truck Emission 

Requirements 

 States including Pennsylvania are precluded 

from establishing any emissions limitations 

other than those required by 40 CFR Part 86.

 Heavy duty vehicle engines are exempt from 

permitting requirements under Exemption 

Category No. 38.

 All non-road engines must comply with federal 

emission standards found in 40 CFR Part 86.

 Only ultra-low sulfur diesel fuel will be 

available.

Performance Standard No. 15.1 and 15.2

 By March 20, 2014 -80% of all trucks 

used to transport fresh water or well 

flowback water must meet U.S. EPA’s 

Final Emission Standards for 2007 and 

Later Model Year Highway Heavy-Duty 

Vehicles and Engines for particulate 

matter (PM) emissions.

 By September 24, 2015 -95% of all 

trucks used to transport fresh water or 

well flowback water must meet U.S. 

EPA’s Final Emission Standards for 

2007 and Later Model Year Highway 

Heavy-Duty Vehicles and Engines for 

particulate matter (PM) emissions.

 U.S. EPA regulates engine 

emissions from highway 

heavy-duty vehicles based 

on the vehicle’s model 

year.66

 States including Pennsylvania are precluded 

from establishing any emissions limitations 

other than those required by 40 CFR Part 86.

 States including Pennsylvania are 

precluded from establishing any 

emissions limitations other than those 

required by 40 CFR Part 86.

 States including 

Pennsylvania are 

precluded from 

establishing any 

emissions limitations 

other than those required 

by 40 CFR Part 86.

 

66 40 C.F.R. Part 86
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 17 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Truck Load-out 

Emissions

Exemption Category No. 3867

 Exemption Category No. 38 requires 

compliance with 95% VOC reduction 

requirements of other equipment such as 

tanker truck load-outs, consistent with § 

60.5413 or alternate test methods as 

approved by the Department.

 None

Regulation No. 3:

 The following sources are exempt because by 

themselves, or cumulatively as a category, they 

are deemed to have a negligible impact on air 

quality:

o Crude oil truck loading equipment at 

exploration and production sites 

where the loading rate does not 

exceed 10,000 gallons of crude oil per 

day averaged on an annual basis.

 Condensate truck loading equipment at 

exploration and production sites that splash fill 

less than 6750 barrels of condensate per year 

or that submerge fill less than 16308 barrels of 

condensate per year.

Natural Gas Production 

Facility Class II General 

Permit G70-A

Regulated Pollutant Limitation.

The registrant shall not cause, 

suffer, allow or permit 

emissions from any registered

Tank Truck Loading Facility of 

any regulated pollutant listed 

in the General Permit 

Registration to exceed the 

potential to emit (pounds per 

hour and tons per year) 

recorded with the registrant‘s 

General Permit Registration 

without effecting a modification 

or administrative update.

To demonstrate compliance 

with the tank truck loading 

emissions in section 11.1.1, 

the registrant shall not exceed 

the maximum throughput limit 

that was recorded with 

registrant‘s General Permit 

Registration without effecting a 

modification or administrative 

update. Compliance with the 

Maximum Annual Throughput

Limitation shall be determined 

using a twelve month rolling 

total.

Glycol 

Dehydrators GP-5

 The owner or operator of each glycol 

dehydrator located at natural gas 

compression and/or processing facility 

shall comply with the applicable 

requirements established in 40 CFR Part 

63, Subpart HH.

 The VOC emissions from the glycol 

 None  The owner or operator of 

each glycol dehydrator 

located at natural gas 

compression and/or 

processing facility shall 

comply with the applicable 

requirements established in 

40 CFR Part 63, Subpart 

HH.

 For still vents and vents from any flash 

separator or flash tank, shall reduce 

hydrocarbon emissions by 95% (98% if 

combustion device used) except where

o Combustion device was 

permitted prior to 01-May-2014, 

and

o Dehydrator is not within 1,320 

feet of a building unit or 

GP12.1 and GP 12.2

 For Total Organic Compounds 

(TOC), total hazardous air 

pollutants (total HAP), or benzene, 

compliance with the applicable 

control requirements of 40 CFR 

Part 63, Subpart HH.

 Emissions from a flare used to 

Natural Gas Production 

Facility Class II General 

Permit G70-A

 In addition to the 

minimum 

requirements in this 

section, area source 

TEG units may also 

be subject to 40 

 

67 Pennsylvania’s Air Quality Permit Exemptions
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 18 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

dehydrator still vent stream, which has a 

total uncontrolled potential emission rate 

of VOC in excess of ten (10) tons per 

year, shall be controlled either by at least 

85% with a condenser, a flare or other air 

cleaning device, or any alternative 

methods as approved by the Department.

o A glycol dehydrator using a 

condenser as an air cleaning 

device shall daily achieve an 

average final exhaust 

temperature of less than 110 

degrees Fahrenheit (110 oF).

o (c) A glycol dehydrator using a 

flare as an air cleaning device 

shall ensure destruction of VOC 

emissions to the flare stack by 

maintaining the heat content of

the flare gas above 300 Btu/scf.

 Visible emissions from a glycol dehydrator 

using a flare shall not exceed either of the 

following limitations:

o Equal to or greater than 10% 

for a period or periods 

aggregating more than 3 

minutes in any one hour.

o Equal to or greater than 30% at 

any time.

 A glycol dehydrator shall not emit 

malodorous air contaminants in such a 

manner that the malodors are detectable 

outside the facility property.

 If a flare is used as an air cleaning device 

for the glycol dehydrator, the owner or 

operator shall maintain a record of daily 

visual observations of the continuous 

presence of a flame or a record of the 

continuous recorder that indicates the 

designated activity area

 Applies to units

o Constructed on or after 01-May2015 with uncontrolled VOC 

emissions > 2 tons per year

o Constructed before 01-May-2015 

with uncontrolled VOC emissions 

> 6 tons per year

o Constructed before 01-may-2015 

with uncontrolled VOC emissions 

> 2 tons per year if unit is within 

1,320 feet of a building unit or 

designated activity area.

control emissions from the glycol 

dehydration unit shall not 

exceed:68

o 0.25 ton Nitrogen Oxides 

(NOx) per month 

averaged over a 12-

month rolling period;

o 0.23 ton VOC per month 

averaged over a 12-

month rolling period; and

o 0.15 ton Sulfur dioxide 

(SO2) per month 

averaged over a 12-

month rolling period.

o Carbon Monoxide (CO) 

emissions from a flare 

used as a control device 

for the dehydrator shall 

not exceed 1.35 tons CO 

per month averaged 

over a 12-month rolling 

period.

o Emissions of Volatile 

Organic Compounds 

(VOC) (excludes 

methane and ethane)

shall not exceed 5.0 

tons/year.

 If a flare is used to control 

emissions from the dehydrator:

o The flare shall be 

operated with a flame 

present at all times when 

gases are vented to it.

o An automatic flame 

ignition system shall be 

installed.

o If the permittee is using 

a pilot flame ignition 

CFR 63, Subpart 

HH.

 Maximum 

Throughput 

Limitation. The 

maximum wet 

natural gas 

throughput to the 

glycol dehydration 

units/ still columns 

shall not exceed the 

throughput limit 

listed in the 

registrant‘s G70-A 

general permit 

registration. 

Compliance with the 

Maximum 

Throughput 

Limitation shall be

determined using a 

twelve month rolling 

total.

 Emission Limits. The 

registrant shall not 

cause, suffer, allow 

or permit emissions 

of hazardous air

pollutants (HAPs) 

and Volatile Organic 

Compounds (VOCs) 

to exceed the 

emission limits listed

in the registrant‘s 

G70-A general 

permit registration.

 Control Devices. 

The following control 

devices may be 

used:

Flares

Enclosed 

 

68 OAC (Ohio Adminstrative Code) rule 3745-31-05(A)(3), as effective 11/30/01
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 19 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

continuous ignition of the pilot flame.

 The owner or operator of a new glycol 

dehydrator, which is not subject to the 

requirements established in 40 CFR Part 

63, Subpart HH and has a total 

uncontrolled potential emission rate of 

VOC in excess of five (5) tons per year 

shall be controlled either by at least 95% 

with a condenser, a flare or other air 

cleaning device, or any alternative 

methods as approved by the Department.

Exemption Category No. 38

 Combined VOC emissions from all the 

sources at the facility less than 2.7 tons 

on a 12-month rolling basis. If the VOCs 

include HAPs, the HAP exemption criteria 

in this paragraph will be met. Compliance 

with this criterion is to be determined 

using any generally accepted model or 

calculation methodology.

 If the exemption criteria cannot be met, 

then a case-by-case plan approval is 

required.

system, the presence of 

a pilot flame shall be 

monitored using a 

thermocouple or other 

equivalent device to 

detect the presence of a 

flame. A pilot flame shall 

be maintained at all 

times in the flare’s pilot 

light burner. If the pilot 

flame goes out and does 

not relight, then an alarm 

shall sound.

o If the permittee is using 

an electric arc ignition 

system, the arcing of the 

electric arc ignition 

system shall pulse 

continually and a device 

shall be installed and 

used to continuously 

monitor the electric arc 

ignition system.

o Any flare, auto ignition 

system, and recorder 

shall be installed, 

calibrated, operated, and 

maintained in 

accordance with the 

manufacturer’s 

recommendations, 

instructions, and 

operating manuals.

 If a condenser (or BTEX 

elimination system) is used to 

control emissions from the 

dehydrator:

o The condenser shall be 

operated at all times 

when gases are vented 

to it.

o The condenser must be

equipped with a 

continuous temperature 

monitoring device that 

continuously monitors 

and records the 

dehydration still vent 

Combustion Devices

Closed Vent System

Carbon Adsorption 

Systems

Condensers

 The registrant shall 

comply with all 

applicable control 

device requirements.

Glycol Dehydration Units 

Recycling Back to Flame 

Zone of the Reboiler:

 If the registrant is 

reducing emissions 

by recycling the 

glycol dehydration 

unit back to the 

flame zone of the 

reboiler, it shall be 

designed and 

operated in 

accordance with the 

following:

a. The 

vapors/overheads 

from the still column 

shall be routed 

through a condenser 

at all

times when there is 

a potential that 

vapors (emissions) 

can be generated 

from the still

column.

b. The reboiler shall 

only be fired with 

vapors from the still 

column and flash 

tank, and natural 

gas may be used as 

a supplemental fuel.
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 20 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

temperature.

o The condenser, 

temperature monitoring 

device and recorder 

shall be installed, 

calibrated, operated, and 

maintained in 

accordance with the 

manufacturer’s 

recommendations, 

instructions, and 

operating manuals.

 Emission Limitation from a flare 

used to control the dehydrator:

o 1.35 tons of CO per 

month averaged over a 

12-month rolling period.

o 0.23 ton of VOC per 

month averaged over a 

12-month rolling period.

o 0.25 ton of NOx per 

month averaged over a 

12-month rolling period.

o 0.15 ton of SO2 per 

month averaged over a 

12-month rolling period.

c. The 

vapors/overheads 

from the still column 

shall be introduced 

into the flame zone 

of the reboiler as the 

primary fuel or with 

the primary fuel 

before the 

combustion 

chamber.

To demonstrate 

compliance with the 

registrant shall 

monitor the 

throughput of wet 

natural gas fed to 

the dehydration 

system on a monthly 

basis for each glycol

dehydration unit.

Representative gas 

sample collection 

and analysis 

frequency for 

dehydration units 

shall be determined 

based on the level of 

HAP emissions from 

the glycol 

dehydration unit of 

the facility as set

forth below:

Each dehydration 

unit exempt from

§ 63.764(d) 

requirements and 

with

federally enforceable 

controls - Upon 

request by the 

Director.

Each dehydration 
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 21 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

unit exempt from

§ 63.764(d) 

requirements and 

without

federally enforceable 

control - (a) An 

initial compliance 

test within 180 days 

of

permit issuance or 

within 180 days of 

start-up of

the dehydration unit, 

whichever is later.

(b) Monitor and 

record bi-monthly 

the actual input 

parameters for GRI 

GLYCalc V3 or 

higher.

Every dehydration 

unit at or above 95% 

of

HAPs major source 

levels exempt from

§ 63.764(d) 

requirements and 

without federally 

enforceable controls

- The registrant shall 

sample and perform 

a wet gas analysis at 

least once each 

year.

Natural Gas 

Processing Plants  In accordance with 25 Pa. Code §§ 

127.11 and 127.12(a)(5), the owner or 

operator of a fractionation unit located at 

an onshore natural gas processing plant 

shall comply with 40 CFR Part 60, 

Subpart KKK – Standards of Performance 

for Equipment Leaks of VOCs from 

Onshore Natural Gas Processing Plants.

 None

 The owner or operator of a 

fractionation unit located at 

an onshore natural gas 

processing plant shall 

comply with 40 CFR Part 

60, Subpart KKK –

Standards of Performance 

for Equipment Leaks of 

VOCs from Onshore Natural

Gas Processing Plants.

 Not Covered by Regulations 3, 6 and 7.  Not Covered by GP12.1 and 

GP12.2.

 Not covered by 

General Permit G30D, G-35A, or G70-

A.

.
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 22 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Turbines Exemption Category No. 38:

 Combustion turbines rated at less than 

1,000 horsepower or 10.7 gigajoules per 

hour.

GP-5

 The owner or operator of a new or 

reconstructed turbine with a rated 

capacity equal to or greater than 1000 

bhp or 10.7 gigajoules per hour (10 

MMBtu/ per hour), based on the higher 

heating value (HHV) of the fuel that 

commenced construction, modification, or 

reconstruction after February 18, 2005, 

shall comply with applicable requirements 

specified in 40 CFR Part 60, Subpart 

KKKK.

 In accordance with 25 Pa. Code §§ 127.1 

and 127.12(a)(5), the owner or operator of 

a new or reconstructed turbine shall not 

exceed the following emissions 

standards:

Turbine Size ≥1,000 BHP and

<5,000 BHP

NOx

ppmvd

corrected 

at

15% O2

CO

ppmvd

corrected

at 15% 

O2

NMNEHC 

(as

Propane) 

ppmvd

corrected 

at 15% 

O2

Total

Particulate

Matter

Lbs/MMBtu

25 25 9 0.03

 None  The owner or operator of a 

Turbine shall comply with 

emissions standards 

specified in 40 CFR Part 60, 

Subpart KKKK.

 Not covered by Regulations 3, 6 and 7.  Micro turbines less than 200 kW are 

exempt.

 Not Covered by GP12.1 and GP12.2.

 Not covered by 

General Permit G30D, G-35A, or G70-

A
Comparison of Air Emission Standards for the Oil & Gas Industry

Issued: May 23, 2014 Page 23 of 23

Item Pennsylvania CSSD Performance Standard Federal Colorado Ohio West Virginia

Turbine Size ≥5,000 BHP and

<15,000 BHP

NOx

ppmvd

corrected 

at

15% O2

CO

ppmvd

corrected

at 15% 

O2

NMNEHC 

(as

Propane) 

ppmvd

corrected 

at 15% 

O2

Total

Particulate

Matter

Lbs/MMBtu

15 25 9 0.03

Turbine Size ≥15,000 BHP

NOx

ppmvd

corrected 

at

15% O2

CO

ppmvd

corrected

at 15% 

O2

NMNEHC 

(as

Propane) 

ppmvd

corrected 

at 15% 

O2

Total

Particulate

Matter

Lbs/MMBtu

15 10 ppm 

or

93%

reduction

5 ppm or 

50%

reduction

0.03

 Compliance with the emissions standards 

in this section shall be considered 

compliance with the NSPS emissions 

standards specified in 40 CFR Part 60, 

Subpart KKKK and 25 Pa. Code Chapter 

122 (relating to national standards of 

performance for new stationary sources).