# Department of Environmental Quality

To protect, conserve and enhance the quality of Wyoming's
environment for the benefit ofcurrent and future generations.

Matthew H. Mead, Governor Todd Parfitt, Director

June 16, 2014

Comments submitted viaemailto oilandgas.whitepapers@epa.gov



### Re: FiveTechnicalWhitePaperson SourcesofEmissionsin theOil and Gas Sector

ToWhom ItMayConcernattheU.S. EnvironmentalProtectionAgencyOffice ofAirQualityPlanning and Standards:

The State ofWyoming Department ofEnvironmental Quality (WDEQ) appreciates the opportunity to comment on the five technical white papers on potentially significant sources ofemissions in the oil and gas sector, which U.S. Environmental Protection Agency (EPA) Office of Air Quality Planning and Standards (OAQPS) released for external peer review on April 15, 2014. The white papers address emissions and mitigationtechniquesfor methane and volatileorganiccompounds (VOCs) from sources in the oil and gas sector. WDEQ has been regulating VOCs emissions from onshore oil and gas production sites and pipeline facilities for overtwenty years. The Departmenthas issued over29,000 permitting actions to date for air emissions associated with production equipment, completion activities, liquids unloading, and compression facilities. The oil and gas sector is comprised ofmany separate and distinct operations, which may vary in type and application by well field or by company-determineddevelopment strategies. Variation is common in the oil and gas industry. EPA noted in its draft repmi

### An Assessment 

### qfthe EnvironmentalImplications ofOilandGas Production:A Regional Case Study that "[t]he oil and natural gas resources in Region 8 are distinctfrom otherreserves located in the United States." (pg. ES--1) 

### Itis WDEQ's experience that such distinction results in highly varied and production-specific air emissions and operations. EPA'sfive whitepapers arebased on a collectionofstudies and assessmentsthatprovide high level summary**information~** but lack site or field specific analyses. WDEQ appreciates both the · challenge and necessity of obtaining current production and site and field data. WDEQ obtains this information during permitting actions and utilizes it as a basis for determining emissions. EPA should expand the scope of these white papers to include more data samples and site specific production information because this data will greatly enhance EPA's ability to gauge the effectiveness of any potential control strategy. EPA is encouraged to expand the scope oftheir white papers to include more data samples and site specific production information in order to effectivelyjudge the impact of any potential control strategy.

In addition to the general recommendation to use more site specific equipmentand production data, the WDEQ provides additional comments on each whitepaper. Comments are organized by typeof equipmentor operation.

The control determination for rod packing emissions is the same as that ofNew Source Performance Standard 

### 0000, which is appropriate. WDEQ's application of best available control technology (BACT) results in similar requirements for compression units. The Division is also aware that some operators are investigating the implementation of a vapor recovery system (VRU) to collect packing

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### WyomingDepartmentofEnvironmental QualityComments FiveTechnical White Papers on Sources ofEmissions in the Oil and Gas Sector June 16,2014 Page 2

emissions and route them back into the gas stream or into the fuel system. There are site specific
concernsfor such control, includingpotential backpressure issues.

Cost values for control ofemissions from the compressor seals will vary significantly depending on the gas composition and size of compressor. It 

### is important for EPA to consider these variables when determining size categories and applicable emissions controls. A small vapor compressor used to control tank emissions or produced gas does not have the same control opportunities as a large, mainline compression unit, even though theirVOC emissions could be comparable.
WDEQ reviewed EPA's questions at the end ofthe white paper. Based on the technical and operational nature of the questions, the Department recommends that EPA continue their cooperative work with operatorsto adequately addressthese questions.

Emissions from completions and ongoingproductionofhydraulically fractured oil wells

EPA's assessment ofemissionswas focused primarily on oil well development inNorthDakota, which is not representative of completions and ongoing production from hydraulically fractured oil wells in various locations across the state ofWyoming. In many cases, site specific limitations such as the quality ofproduced gas and availability ofpipeline determine whether areduced emissions completion (REC), or green completion, can be utilized. EPA should take additional measures, including surveying oil and gas operators, to determine the feasibility of requiring the capture of produced gas from hydraulically fractured oil wells. WDEQ is aware ofadditional measures that operators may use to reduce flaring emissions associated with hydraulically fractured oil wells. Companies may install mechanical refrigeration units, JouleThompson skids, or similar natural gas liquids (NGL) recovery equipment to reduce the heat content of the gas being f1ared. These mitigation measures help reduce flaring emissions while providing a potentially valuable product for sale. EPA should note that in some states with minor source BACT authority, the use ofNGL recovery and storage equipment can trigger permitting, so operators may have

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### pri9rto installing and ?peratingequipment**designe~ ~o** **re~uce** 

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### When considering control technologies and work practices to reduce emissions associated with completions, EPA must consider workplace safety. WDEQ is aware that some forms offlaring, such as pit flaring, are performed for safety reasons. Some operators use pit flaring to control VOC emissions from drilling fluids, whichpose apotential fire and/orexplosionhazard. Theuses ofRECmay reducethe need for pit flares, however there may be instances when pit flaring will still be necessary as amatter of safety. Monitoring of control devices needs to be addressed when examining potential ways to reduce VOC emissions from produced gas from oil wells. The composition ofthe produced gas can vary significantly and this in turn can affect the design and operation of any emissions controls, especially flares or combustors. WDEQ has an operational standard that non-emergency flares be smokeless. EPA should consider effective monitoring methods to ensure proper operation. In some instances, required periodic Method 9readings may notbethe mosteffective monitoring method.

### Wyoming DepartmentofEnvironmental Quality Comments Five Technical WhitePapers on Sources ofEmissions in the Oil and Gas Sector June 16,2014 Page 3

In addition to smokeless provisions, WDEQ requires monitoring ofa pilot flame or a combination of temperature and flow monitoring to ensure proper operation ofthe flare or combustor and to verify that VOC vapors are not being vented. Other states also require some form ofmonitoring to demonstrate the control is working properly. EPA should review current monitoring practices for controls that reduce VOC emissions from hydraulically fractured oil wells and consider such monitoring in any determination they make to require VOC emissions controls.

WDEQ addresses equipment leaks in two parts and on a case-by-case basis. The first part is emission quantification. FugitiveVOC emissions are determined using eitherarepresentative oractual component count, a determination of service for each component, an assumed leak rate, and representative gas analyses. Component count and gas analysis are the two mostvariable factors for oil and gas production sites. Componentcounts vary based on well production and company-determined processing equipment. WDEQ has noted significant variations in both factors, even within the same producing field. WDEQ
uses representative gas analyses to determine VOC content ofthe leaking vapors. EPA should workwith states and operators to obtain a better understanding ofthe variability offugitive equipment leaks before developing control requirements oremissions standards.
The second part of WDEQ methodology for addressing equipment leaks is leak detection and repair (LDAR). As previously mentioned WDEQ addresses equipment leaks on a case-by-case basis and does not unilaterally require LDAR programs at production sites. For example, a single well producing low API gravity crude oil may have insignificant VOC emissions from leaks, but an oil well that produces high API gravity oil and gas may have significantemissions from equipment leaks. EPA should consider such variability when consideringcontrollingorreducing fugitive VOC emissions from equipmentleaks.

Not only do VOC emissions from equipment leaks vary among production sites, but so do the LDAR programs implemented by various operators throughout Wyoming. WDEQ applies minimum standards to LDAR programs, but just as production site configuration and operation vary, so too does the application ofLDAR. Some production wells are closely grouped in a producing field, while wells in otherfields cat1 be a-notable aistmfce-apart. Some-production sites feed-to licjuias collectioi1 facilities while others separate and store liquids onsite. There is also notable variation in the way operators go about determining leaks. Some operators use optical imaging devices to detectthe presence ofleaks and then apply derived leak rates to the leak. Other operators will measure emissions from the leak using a Method 21 monitoring instrument. Both approaches are effective at identifying leaks, but may have significantly different implementation costs. There may be technical issues that affect an instrument's ability to detect leaks from a single component. There may also be environmental factors, such as wind speed, that affect the implementation ofa LDAR program that is based on an optical imaging device. Before determining whetherto require LDAR, EPA mustreview and considerthe differences between the various forms ofLDAR. Liquids unloading

EPA's assessment ofliquids unloading focused on technologies and work practices used within the well casing or annulus. WDEQ has not required operators to implement a specific type ofliquid unloading practice, but focuses on controlling emissions when unloading events occur. Best management practices (BMP) have been implemented through permits and permit requirements specific to well blowdown and venting. These practices include blowing down the well through existing tanks and separators, whichWyomingDepartmentofEnvironmental QualityComments FiveTechnical WhitePapers on Sources ofEmissions in the Oil and Gas Sector June 16, 2014 Page4

may be controlled by combustion devices, or sending produced gas and liquids from blowdowns to a central gatheringfacility.

Oil and gas production sites are located in very different geographical areas throughout the country. At
some locations, line powermay be readily available, whereas at othermore remote locations line poweris simply not available. WDEQ relies on the experience ofthe operators to determine the best liquids unloading procedure and implement BMP on a case-by-case basis to minimize emissions from unloading events. Operators are required to maintain records of blowdown events and resulting emissions, and provide them to the Division. Based on historical data from such reports for natural gas wells, VOC emissionsfrom blowdowns are often in the order ofpounds. EPA should examine mitigation and control
measures that can be applied on the surface both at the well head and downstream ofthe well head. In addition to using existing production equipment to control VOC emissions from blowdown events, WDEQ is aware ofspecialized portable equipmentthat can be used to control emissions from unloading events. EPA should review additional methods for control unloading emissions because although there
aremanyeffectivecontrol measures, noteverycontrolmeasurewill be effective in every situation.

Pneumatic devices

EPA's analysis ofpneumatic devices was very narrow. EPA reviewed older studies that only looked at approximately 15 controllers in the rocky mountain region. WDEQ understands that it was EPA's intent to survey controllers in well fields throughout the United States, however a sample size of only 15 controllers does not adequately representthe distribution ofpneumaticcontrollers in theregion. WDEQ's recent experience is that while line power is becoming more prevalent, there are still many areas in Wyoming that are too remote for line power. Gas driven pneumatic devices are, and will continue to be, necessary for some operations in specific locations.

EPA's control determination relied heavily on the use of electric devices or devices operated with instrument air. In remote locations, a generator would be required to operate the electric devices and electric air compressor. A fuel-fired compressor could be used in place of a fuel-fired generator to produce instrument air. In eithercase, there would be additional emissions associated with either electric
-or-instrument air- d-evices. --EPA nl.ust consider ancillary equiprnent and-associated air-ernissions for remote locations.

EPA did not evaluate a wide variety ofcontrol measures for pneumatic devices. Operators in Wyoming control VOC emissions from gas driven pneumatic devices in a variety ofways. Some operations route emissions to the fuel gas system, while others route emissions to existing VOC controls. In some instances, operators take advantage ofequipment consolidation and reduce the overall number of gas driven pneumatic devices. EPA should consider additional measures for reducing VOC emissions from pneumaticdevices.
WDEQ noted that EPA's evaluation did not address pneumaticpumps used for heattrace systems, which
can be a significant source ofVOC emissions. EPA did consider pneumatic pumps used for chemical injection, howeverthese pumps tend to be much smallerwith fewer emissions. WDEQrequires operators to reduce VOC emissions from pneumatic heat trace pumps through the application ofBACT. EPA should considerrequiring operatorsto control VOCemissions from theirpneumaticheattrace pumps. WDEQ also noted that EPA did not include actual emissions data from 2012 or 2013. More recent data will likely demonstrate loweremissions from new equipment as aresult ofthe application ofNew Source Performance Standard Subpart 

### 0000, which requires low bleed pneumatic devices at oil and gasWyoming DepartmentofEnvironmental QualityComments FiveTechnical WhitePapers on Sources ofEmissions in the Oil and Gas Sector June 16,2014 Page 5 production sites. WDEQ further noted that as.result ofusing older information, emissions ofgreenhouse gases (GHG) were determined using the older global warming potential (GWP) of 21 for methane. Effective January 1, 2014, the GWP ofmethane is 25 (78FR71904-71981). EPA should base C02e greenhouse gas emissions on current GWPs, which will be used to determine 2013 reported GHG emissions from oil and gas sources that are subject to the mandatory greenhouse gas (GHG) repotiing rule.

In conclusion, oil and gas development is a diverse and complex industry, and any effective emissions reduction strategy must account for the varying types of operations and varying types of production. WDEQ suggests that EPA revise the five white papers to include more recent and robust emissions data and to accountfor the variability in oil and gas fields and operations. WDEQ appreciates the opportunity to provide comments on these five white papers, and looks forward to working with EPA to control emissions in the oil and gas sector.

Should you have any questions, please contactme at (307) 777-7391.

Steven A. Dietrich WDEQ Air QualityAdministrator

cc: ToddParfitt, WDEQDirector JeremiahWilliamson, OfficeoftheAttorneyGeneral Jerimiah Rieman, GovernorMead'sPolicyOffice JenniferCederle, AQD ColeAnderson,AQD