### MEMORANDUM

TO: Lisa Biddle, EPA

FROM: Brent Ruminski, ERG

Sarah Yates, ERG

DATE: March 3 1

, 201 5

SUBJECT: Analysis of Active Undergrou nd Injection for Disposal Wells ( DCN

SGE 00736)

1.0 I NTRODUCTION

An i njection well is a device that places fluid deep underground into porous rock formations (e.g., sandstone, limestone ) or into or below the shallow soil layer. In its underground injection well control (UIC) program codified in 40 CFR Parts 144 to 148, EPA established six classes of underground injection wells. These classes and their relationship to the unconventional oil and gas 1 industry are described in S ection D .2 of the Technical Development Document for Proposed Effluent Limitations G uidelines and Standards for Oil and Gas Extraction ( DCN SGE 00704 ) (hereafter, referred to as the TDD)

. Class II wells inject fluids associated with oil and natural gas production. The three types of Class II wells include :

 Hydrocarbon storage wells ;

 E nhanced recovery wells ; and

 D isposal wells

. Only enhanced recovery and disposal Class II wells are used to inject water.

The use of e nhanced recovery wells involves the inject ion of produced water, brine, salt
water , water, steam, polymers, or carbon di oxide into oil

- bearing formations to recover residual oil and

— in some limited applications

— natural gas. 2 I njected fluid can move through permeable formation s to decrease the viscosity or displace small amounts of extractable oil and gas, which then becomes less resistan t to flow and more available for production

. In a typical enhanced recovery project, a single Class II enhanced recovery injection well is surrounded by multiple oil

1 UOG resources consist of crude oil and natural gas produced by wells drilled into low porosity, low permeability formations. Development of UOG resources often requires hydraulic fracturing of the reservoir rock by injecting large amounts of fracturing fluid at high pressures to create a network of fissure s in the rock formations

, giv ing the oil and/or natural gas a pathway to travel to the well for extraction.
2 The injection of fluids for hydraulic fracturing is also a form of enhanced recovery. See Legal Environmental Assistance Foundation v. EPA, 276 F .3d 1253 (11 th Cir. 2001). However, Congress amended the Safe Drinking Water Act to exempt hydraulic fracturing (except where diesel fuels are used) from regulation under the UIC
program ( SDWA section 1421(d)(1) )

. Because there are currently no Class II permits for hydraulic fracturing activities, ERG did not consider wells that have been hydraulic ally fractured within the context of this memorandum.Memorandum

M arch 3 1 , 2015 Page 2

and gas production wells. These p roduction wells bring oil and gas to the su rface , often with large volumes of produced water (brine) from the formation ( DCN SGE00132 ) . Many enhanced recovery projects consist of a closed loop system in which produced water from the production wells is disposed of by injection into the adjacent Cla ss II enhance d recovery well ( DCN SGE00613 ; DCN SGE00623; DCN SGE00132 )

. According to communication with industry, t his configuration is not possible in unconventional formations because injected fluids cannot readily flow through the low permeability form ation ( DCN SGE00613 )

. The use of disposal wells involves the inject ion of wastewater associated with oil and gas extraction for permanent disposal

. ERG collectively refers to all wastewater streams generated during oil and gas extraction as “oil and gas extraction wastewater ” defined by EPA as sources of wastewater pollutants associated with production, field exploration, drilling, well completion, or well treatment

. 3

 Produced water

— the water (brine) brought up from the hydrocarbon

- bearing strata durin g the extraction of oil and gas. This can include formation water, injection water, and any chemicals added downhole or during the oil/water separation process . Based on the stage of completion and production the well is in, produced water can be further b roken down into the following components:

— Flowback

— the wastewater generated by wells during the flowback process of well completion. After the hydraulic fracturing procedure is completed and pressure is released, the direction of fluid flow reverses, and t he fluid flows up through the wellbore to the surface. The water that returns to the surface is commonly referred to as “flowback.”

— Long

- term produced water

— the wastewater generated by wells during the production phase after the flowback process. Long

- term produced water continues to be produced throughout the lifetime of the well.

 Drilling wastewater

— the liquid waste stream separated from recovered drilling fluid ( e.g., mud) and drill cuttings during the drilling process. Drilling fluid is the circulating fluid used in the rotary drilling of wells to clean and condition the hole and to counterbalance formation pressure

. One option for managing oil and gas extraction wastewater is transport to and injection into a disposal well (DCN SGE00132)

. All types of oil and gas extraction wastewater (e.g.,

c o nventional, CBM, UOG ) can be disposed of in Class II disposal wells

. T he leading method of UOG extraction wastewater management throughout the U.S. is injection into a Class II disposal well ( DCN SGE00693.A 0 3 ). Fu rthermore, available literature and communication with industry indicates that UOG operators primarily use Class II disposal wells and typically do not use Class II enhanced recovery wells ( DCN SGE00 6 35 ; DCN SGE00276; DCN SGE00625 )

.

3 Stormwater is not considered a source of UOG extraction wastewater. In general, no NPDES permit is required for discharges of stormwater from any field activities or operations associated with oil and gas production, except as specified in 40 C.F.R. 122.26(c)(1)(iii) for discharges of a reportable quantity or that contribute to a violation of a water qu ality standard . States may impose additional requirements for management of drilling site stormwater.Memorandum

M arch 3 1 , 2015 Page 3

T his memorandum document s the calculations and analyses ERG performed to support the i nformation on Class II disposal wells that is presented in Section D

. 2 in the TDD

. This memorandum is organized into the following section s :

 Section 2.0 describes the general methodology that ERG used to tabulate the data in Tabl e D

- 2 in the TDD (Chapter D, Section D .2 ) ;

 Section 3.0 describes the results of the analysis;

 Section 4.0 describes data quality and implications of key assumptions;

 Section 5.0 describes the QC procedures tha t were followed throughout the analysis ;

 Section 6.0 lists all of the data sources used in the analysis; and

 Attachment 1 contains the results of the analysis ( DCN SGE 00736.A 0 1)

.
2.0 G ENERAL M ETHODOLOGY

Table D

- 2 in the TDD ( DCN SGE 00704) contains three types of data relat ed to injection for disposal wells

, on a state

- by

- state basis :

 Number of Active Disposal Wells (2011

- 201 4 )

 Average Disposal Rate Per Well (gpd/well)

 State Disposal Rate (MGD)

The following three subsections describe how ERG calculated and/or tabulated these three types of data for each state. Attachment 1 ( DCN SGE00736.A 0 1) contains the calculations and detailed documentation on a state

- by

- state basis

. ERG made several assumptions throughout this analysis in order to present available data in a meaningf ul way for the TDD. Potential implications of these assumptions are described in Section 4.0

.

2.1 Number of Active Disposal Wells

The Well Count Documentation tab in Attachment 1 ( DCN SGE00736.A 0 1 ) documents how ERG tabulated active disposal wells on a state

- by

- state basis. For each state, this tab includes the primary reference for well data (in column C, “DCN for Well Data”) 4 , the date that the reference was accessed and last updated, and how ERG tabulate d the number of active disposal wells using the data for this analysis

. E RG primarily used state agency oil and gas databases to identify the number of active C lass II disposal wells

. Most state databases provide active well counts for the 201 2 to 201 4 time frame 5 and include, for each well record, data fields such as API #, longitude, latitude, well status (e.g., active, plugged, shut in), and well type (e.g., oil, gas, enhanced recovery, disposal).

To d etermine the number of active Class II disposal wells, ERG applied filters to the appropriate data fields in the individual state databases

. The two primary data fields ERG used

4 For some states, ERG obtained active disposal well counts from EPA OGWDW (DCN SGE01012) and obtained injection volume data from the state. Such states will be listed in the EPA Implementation States tab and will also have their own tab.
5 A snap shot of active disposal well counts was obtained from individual state agencies. Therefore, the data year for each state varied depending on the availability of d ata.Memorandum

M arch 3 1 , 2015 Page 4

were well status and well type. ERG documented the specific filters applied fo r each state dataset within the Well Count Documentation tab. ERG included C lass II disposal wells that were active or under construction

. Specific acronyms for well status and type vary by state. ERG chose the necessary filters that represent the desired category of wells (i.e., active Class II disposal wells) based on the data dictionary for the state database, where available. Otherwise, ERG used engineering judgment to determine the appropriate filters. When available, ERG referenced data dictionaries p ublished by state agencies to verify the appropriate filters. ERG specifically excluded inactive

, plugged, permitted, proposed, temporarily abandoned, and/or Class II enhanced recovery or hydrocarbon storage wells

. With the exception of Oklahoma and Michigan

, ERG excluded wells on tribal lands that were reported by EPA OGWDW (DCM SGE01012)

. EPA OGWDW confirmed that the active disposal well counts for the states of Oklahoma and Michigan excluded those located on tribal lands. Therefore, ERG added the number of active disposal wells on tribal lands in these two
states. 6 In addition to the active disposal wells located on tribal lands in Oklahoma and Michigan, EPA OGWDW reported 115 active disposal wells on tribal lands in eight other states but it w as unclear if the state database s already contained them. Therefore, ERG did not add these 115 wells to these states.

2.2 Average Disposal Rate Per Well (gpd/well)

The Disposal Rate Documentation tab in Attachment 1 (DCN SGE00736.A 0 1) documents how ERG calcula ted average disposal rates per well on a state

- by

- state basis

. For most states, ERG used the following procedure :

1. First, ERG identified total annual volumes (barrels) 7 of oil and gas produced water sent to injection for disposal wells in each state as documented in Attachment 1 (DCN SGE00736.A 0 1)

. F or as many states as possible (10 states )

, this value was obtained from the same state agency reference used to identify the number of active C lass II disposal wells (see Section 2.1 ) . These data years ranged from 2009 to 2013

. For states where state oil and gas databases did not provide relevant data (1 4 states), these volume data were obtained from Argonne National La boratory’s (ANL) 2009 report titled Produced Water Volumes and Management in the United States (DCN SGE00182). 8 This report provides the total volume of oil and gas produced water sent to a specified number of active disposal wells in 2007.

2. For each state, ERG calculated the aver age disposal rate per well (gpd/well) by dividing the total annu a l volume (barrels) by 365 days/year, divid ed by the number of disposal wells active in the same year , and multipl ied by a conversion

6 Oklahoma and Michigan have two separate rows in the Well Count Documentation tab in Attachment 1 ( DCN SGE00736.A1 ). One row is for disposal wells on tribal lands within the state and the other row is for disposal wells in the remainder of the state. 7 The oil and gas industry typically reports volumes in barrels, where 1 barrel is equivalent to 42 gallons.
8 The 2009 ANL report (DCN SGE00182) and the other available literature used for this analysis use the same definition of the term “oil and gas produced water” as is listed in Section 1.0 of this memorandum, where oil and gas produced water includes both flowback and long

- term produced water. The ANL r eport also relied on state oil and gas agencies to estimate state level disposal well counts and volumes.Memorandum

M arch 3 1 , 2015 Page 5

factor of 42 (gallons/barrel)

. As explained above, for many states this calculation

was made with 2007 volumes and well counts. The result represents the average disposal rate per well (gpd/well) based on historical injection volume data

. 9 This calculated rate is not related to the permitted or operational capacity of the well. 10

2.3 State Disposal Rate (MGD)

To provide context about how the availability of injection for disposal varies between regions with UOG extraction 11

, for each state, ERG calculated the state disposal rate (MGD) using Equation 1

. Equation 1

Where,

N = N umber of active disposal wells identified using methodology in Section 2.1 DR avg = Average disposal rate per well (gp d/well) using methodology in S ection 0

The Summary of Results tab in Attachment 1 (DCN SGE00736.A 0 1) contains this calculation. As explained in Sections 2.1 and 0

, respectively, the active disposal well counts are based pr imarily on 201 2 through 201 4 data while the average disposal rates per well (gpd/well) are based o n a mixture of 2007 through 2013 data. ERG used the most up

- to

- date data possible in order to estimate the most up

- to

- date state disposal rates (MGD) in Table D

- 2 of the TDD

.
3.0 S UMMARY OF R ESULTS

For each state, t he Summary of Results tab in Attachment 1 ( DCN SGE00736.A 0 1) contains the number of active disposal well counts, average disposal rate per well (gpd/well), and state disposal rate (MGD) . This tab contain s all of the data presented in Table D

- 2 in the TDD.

The Summary of Results tab presents the results by state sorted by geographic region s as assigned in the EIA Annual Energy Outlook reports (DCN SGE00486). However , Texas and New Mexico are both split into two different geographical regions (i.e., Gulf Coast and Southwest) by EIA. Because ERG presents the results by state, ERG combine d the EIA “ Gulf Coast ” and “ Southwest ” regions into one category for this analysis to keep state data for Texas and New M exico together

. For each region, ERG sorted the states by highest to lowest state disposal rate (MGD). Because ERG used different source s for active disposal well counts and

9 Typical average injection rates may vary for commercial and operator (private) Class II disposal wells, both of which are included in the well count s and injection volumes used to calculate the average disposal rate.
10 Capacity is a function of the salinity of the injected fluid, injection pressure permit limit (if applicable), and/or injection rate permit limit (if applicable ) (DCN SGE00279).
11 See S ection D.2.3 in the TDD for more information about how the availability of Class II disposal wells affects the management of UOG extraction wastewater.Memorandum

M arch 3 1 , 2015 Page 6

average disposal rates, some states with active disposal wells have disposal rate data gaps

. ERG sorted these states by highest to lowest count of acti v e disposal well counts.

4.0 D ATA Q UALITY AND A SSUMPTIONS
ERG did not substantiate individual well records within the underlying databases (e.g., well

- by

- well review). However, ERG did compa re results of active number of disposal wells and injection volumes from this analysis to the following references and confirmed that they generally agree. As such, the datasets are considered sufficiently accurate to observe trends at the state, regional, and national levels.

 Argonne National Laboratory’s (ANL) 2009 report titled Produced Water Volumes and Management in the United States (DCN SGE00182);

 University of Oklahoma’s 2014 technical presentation: Class II Underground Injection Control Well Data f or 2010

– 2013 by Geologic Zones of Completion, Oklahoma ( DCN SGE01089); and

 Test data from states working towards e

- reporting in EPA’s Office of Ground Water and Drinking Water’s National UIC Database (not publicly available ). 12

As described in Section 2.0 and in the bullet points below , several assumptions were necessary to complete this analysis. These assumptions may inflate or deflate the values presented in the TDD Table D

- 2 and are described below. As such, the results from this analysis should be used with careful consideration of their strengths and limitations

.

 Calculation of the average disposal rate per wel l (gpd/well) : ERG included all

we lls identified as active even if some of these wells reported zero injection volume. This assumption may deflate the average disposal rate per well but only affects states where ERG used state databases as the source for injection volumes ( i.e., TX, OK, NM , MI, NY, AK). However, ERG excluded wells that were identified as just being drilled because they could not have injected any
wastewater.

 Calculation of the state disposal rate (MGD) : ERG included the number of disposal wells identified as currently bein g drilled (e.g., under construction) in the active number of disposal wells. This assumption may inflate the current state injection rates but was intended to capture wells that will inevitably come online in the near future. However, ERG excluded wells fr om all calculations that were only permitted or proposed new well projects because these wells may be terminated even after they are permitted or proposed (i.e., may never come online)

.

 Missing v olume d ata : ERG was unable to identify injected volumes for Wyoming and Illinois both of which have a substantial number of active disposal wells.

12 EPA OGWDW is moving towards using an electronic reporting system for state primacy agencies, but it is not complete. A number of states have submitted some amount of data as they work to develop data flow, but most Class II states with data are not final and there is a range of data quality. As there are known to be data gaps and the data is not approved b y the state, it is not in the public record and is not used for official analyses.Memorandum

M arch 3 1 , 2015 Page 7

Therefore, t he total volume of produced water injected into disposal wells in the

nation estimated by this analysis may be an underestimate. These s tates are highlighted red in the Summary of Results tab in Attachment 1 (DCN SGE00736.A 0 1).

 Number of active disposal wells : As explained in Section 2.1 , EPA OGWDW reported 115 active disposal wells on tribal lands in eight different states that ERG excluded from this analysis because it was unclear if the state databases also contained these wells. However, ERG did include the majority of active disposal wells on tribal lands reported by EPA OGWDW. 13

5.0 Q UALITY C ONTROL P ROCEDURES
All of the analyses presented in this memorandum adhered to the Environmental Engineering Support for Clean Water Regulations Programmatic Quality Assurance Projec t Plan (PQAPP) (DCN SGE00957) and the Unconventional Oil and Gas (UOG) Supplemental Quality Assurance Project Plan (SQAPP) (DCN SGE00 958 ), including collecting, evaluating, and analyzing existing data and information about underground injection disposal well s.
Specifically, ERG used the procedures described in Section 4 of the PQAPP to gather and manage existing data in support of the UOG proposed rulemaking. ERG staff entered reference information for relevant sources into the UOG Literature Review database. The ERG index keeper reviewed all reference information, assigned each reference a Document Control Number (DCN ), imported the reference information into the UOG Project File Index database, and saved referenced files i n the Electronic Project File folder.

ERG also used the procedures described in Section 3 of the SQAPP when collecting existing data for use in the UOG proposed rulemaking. ERG used a combination of sources, including reports, papers, and online databases from state regulatory agencies such as departments of environmental protection and oil and gas commissions. ERG assigned all references used in these analyses with one of the following s ource flag s ( DCN SGE00 958 ) :

 Source Flag A

- Journal articles and docum ents prepared by or for a government agency (e.g., site visit reports, industry meeting notes);

 Source Flag B

- Documents prepared by a verified 14 source that include citation information (e.g., operator reports, vendor documents, university publications);

 Source Flag C

- Documents prepared by a verified source that do not include citation information (e.g., operator reports, vendor documents, conference presentations); and

 Source Flag D

- Documents prepared by a source that could not be verified and that do not include citation information.

13 This included the 792 active disposal wells reported by EPA OGWDW in Oklahoma and Michigan that EPA OGWDW confirmed were not already included in the disposal well counts f or those states (see Section 2.1 ).
14 ERG considered sources as “verified” if we were able to find information about the author outside of the reference document. ER G primarily verified information by looking for company/organization websites that confirmed the author’s affiliation with the UOG industry.Memorandum

M arch 3 1 , 2015 Page 8

ERG followed the procedures described in Section 7.0 of the PQAPP to generate, evaluate, and analyze data using a spreadsheet. ERG conducted the following QA checks during the analyses:

 ERG created the Injection for D isposal Well Data spreadsheet provided in Attachment 1 ( DCN SGE 00736.A 0 1 ) to track relevant data and to document analyses. ERG performed a 100 percent check of all data entry, manipulations and calculations, and documented these in the internal version of the spreadsheet.

 For all analys e s performed in state specific Access databases, one team member created queries and another team member reviewed the design and logic of the queries. ERG documented these checks in the internal version of the Injection for D isposal Well Data spreadsheet provided in Attachment 1 ( DCN SGE 00736.A 0 1 )

.

 ERG had a senior staff member familiar with ELGs and the UOG proposed rulemaking review the results from the Injection for Disposal Well Data spreadsheet provided in Attachment 1 ( DCN SGE 00736.A 0 1 ).

6.0 R EFERENCES

Table 1 provides citations for references used in the s e analyses and their assigned source flag.

Table 1 . References

DCN State Full Citation Source Flag a

SGE00132 Multiple U.S. EPA. 2011. Underground Injection Control Program: Class II Wells

—

Oil and Gas Related Injection Wells (Class II). Downloaded on 8/31/2011. A

SGE00138 Multiple U.S. EPA. 2010. 2010 UIC Well Inventory 2010. Available online at:

http://water.epa.gov/type/groundwater/uic/class2/index.cfm A

SGE00182 Multiple Argonne National Laboratory (Clark, C.E., et al.). 2009. Produced Water

Volumes and Management Practices in the United States. Prepared for Department of Energy (DOE). A

SGE00276 N/A US EPA. 2012. Meeting with XTO Energy, Inc. about Unconventional Oil

and Gas Sanitized. A

SGE00279 Multiple U.S. EPA. 2012. Meeting Summary: Conference Call with North Star

Disposal, Inc Regarding Underground Injection Operations in Ohio. (July 2). A

SGE00382 CO Colorado Oil and Gas Conservation Commission (COGCC). 2012. List of

Currently Active Class II Underground Injection Control Well as of January 2012. Downloaded on 12/21/2012. Available online at: http://cogcc.state.co.us/Library/ActiveUIC2012_01.pdf

. A

SGE00383 KS Kansas Geological Survey (KGS). 2012. Kansas Wells. Downloaded on

12/21/2012. Available online at: http://www.kgs.ku.edu/PRS/Ora_Archive/ks_wells.zip

. A

SGE00384 KS Kansas Geological Survey (KGS). 2004. Oil and Gas Well Database

Abbreviations. Downloaded on 2/4/2013. Available online at: http://www.kgs.ku.edu/Magellan/Elog/status.html

. AMemorandum

M arch 3 1 , 2015 Page 9

Table 1 . References

DCN State Full Citation Source Flag a

SGE00385 LA Louisiana Department of Natural Resources (LADNR). 2012. Produced

Fluid Disposal Wells By Field. Office of Conservation. Downloaded on 12/21/2012. Available online at: http://report s.dnr.state.la.us/reports/rwservlet?SRCN4282J_p

. A

SGE00386 LA Louisiana Department of Natural Resources (LADNR). 2012. UIC Well

Class Type. Office of Conservation. Downloaded on 12/21/2012. Available online at: http://sonris.com/

. A

SGE00387 LA Louisiana Department of Natural Resources (LADNR). 2012. Status Code

Description. Office of Conservation. Downloaded on 12/21/2012. Available online at: http://sonris.com/

. A

SGE00388 MO Missouri Department of Natural Resources (MODNR). 2012. Oil and Gas

Permits. (December 19). Accessed on 12/21/2012. Available online at: http://www.dnr.mo.gov/geology/geosrv/do cs/permits

- 12

- 19

- 2012.xls

. A

SGE00389 MT Montana Board of Oil and Gas Conservation (MTBOGC). 2012. UIC

Wells. Accessed on 12/21/2012. Available online at: http://www.bogc.dnrc.mt.gov/WebApps/DataMiner/UIC/UICWells.Aspx

. A

SGE00391 ND North Dakota Industrial Commission (NDIC). 2013. Well Type Definitions.

Department of Mineral Resources, Oil and Gas Division. Last Accessed on 2/4/2013. Available online at: https://www.dmr.nd.gov/oilgas/codehelp.Asp

. A

SGE00392 ND North Dakota Industrial Commission (NDIC). 2013. Well Status

Definitions. Department of Mineral Resources, Oil and Gas Division. Last Accessed on 2/4/2013. Available online at: https://www.dmr.nd.gov /oilgas/codehelp.Asp

. A

SGE00393 NE Nebraska Oil and Gas Conservation Commission (NOGCC). 2012. Well

Data. Downloaded on 12/21/2012. Available online at: http://www.nogcc.ne.gov/Publications/NebraskaWellData.zip

. A

SGE00394 NE Nebraska Oil and Gas Conservation Commission (NOGCC). 2012. Data

Dictionary. Downloaded on 12/21/2012. Available online at: http://www.nogcc.ne.gov/Publications/NebraskaWellStatus_TypeCodes.pdf A

SGE00397 OH Ohio Department of Natural Resources (OHDNR). 2012. Risked Based

Data Management System (RBDMS) Database. Downloaded on 12/21/2012. Available online at: http://ohiodnr.com/mineral /production/tabid/15389/Default.Aspx

. A

SGE00398 OH Ohio Department of Natural Resources (OHDNR). 2012. Well Status

Codes. Downloaded on 2/4/2013. Available online at: http://oilgas.ohiodnr.com/Well

- Information/Well

- Status

- Classification

Codes.Aspx

. A

SGE00399 NM Petroleum Recovery Research Center (PRRC). 2012. All Wells Databa se.

Downloaded on 2/4/2012. Available online at: http://octane.nmt.edu/gotech/Petroleum_Data/allwells.Aspx

. A

SGE00400 SD South Dakota Department of Environmental & Natural Resources

(SDDENR). 2012. Injection Data. Downloaded on 12/20/2012. Available online at: http://www.sdgs.usd.edu/pubs/og/UIC_2012_InjectionData.xlsx

. A

SGE00401 SD South D akota Department of Environmental & Natural Resources

(SDDENR). 2012. Explanation of Database Fields and Terms. Downloaded on 12/31/2012. Available online at: No longer available. AMemorandum

M arch 3 1 , 2015 Page 10

Table 1 . References

DCN State Full Citation Source Flag a

SGE00402 TX Texas Railroad Commission (TXRCC). 2012. Injection & Disposal Query

Criteria. Accessed on 5/28/2013. Available online at: http://webapps2.rrc.state.tx.us/EWA/uicQueryAction.do

. A

SGE00403 UT Utah Department of Natural Resources (UTDNR). 2012. Well Information

Search. Accessed on 2/4/2013. Available online at: http://oilgas.ogm.utah.gov/Data_Center/LiveDat a_Search/well_data_looku p.cfm

. A

SGE00405 WY Wyoming Oil and Gas Commission (WOGC). 2012. Well Header Data

111412. Downloaded on 12/19/2012. Available online at: http://wogcc.state.wy.us/urecordsMenu.cfm?Skip='Y'&oops=#oops#

. A

SGE00406 WY Wyoming Oil and Gas Commission (WOGC). 2013. Codes for Well Files.

Downloaded on 2/4/2013. Available online at: http://wogcc.state.wy.us/codes.html

. A

SGE00407 WV West Virginia Department of Environmental Protection (WVDEP). 2012.

Oil and Gas Well Search. Accessed on 12/21/2012. Available online at: https://apps.dep.wv.gov/oog/wellsearch_new.cfm

. A

SGE00486 All Energy Information Administration. 2013. Assumptions to the Annual

Energy Outlook 2013. A

SGE00498 AR Arkansas Oil and Gas Commission (AOGC). 2012. Status Code Key for

Online Database. Downloaded on 12/21/2012. A

SGE00499 AR Arkansas Oil and Gas Commission (AOGC). 2013. Welcome to the

Arkansas Oil and Gas Commission Online Production and Well Information. Accessed on 6/14/2013. A

SGE00517 CO Colorado Oil and Gas Conservation Commission (COGCC). 2011. COGCC

Underground Injection Control and Seismicity in Colorado. A

SGE00526 AL Geological Survey of Alabama

- State Oil and Gas Board (AL OGB). 2013.

Well Records Database. Accessed on 6/4/2013. A

SGE00537 CA Horsley Witten Group. 2011. California Class II Underground Injection

Control Program Review. A

SGE00549 MI Michigan Department of Environmental Quality (MIDEQ). 2013. Injection

Well Data. Accessed on 5/28/2013. A

SGE00550 MI Michigan Department of Environmental Quality (MIDEQ). 2013. Well

Type and Status Codes. Accessed on 5/28/2013. A

SGE00551 MS Mississippi Oil and Gas Board (MSOGB). 2013. Well Information Report

Search. Accessed on 6/4/2013. A

SGE00557 ND North Dakota Industrial Commission (NDIC). 2014. Basic Subscription

Services

- Well Index. Department of Mineral Resources, Oil and Gas Division. Last Accessed on 1 / 27 /2014. A

SGE00613 N/A U.S. Environmental Protection Agency (U.S. EPA). 2013. Meeting with

industry representatives about the unconventional oil and gas effluent guideline rulemaking. (February 28). A

SGE00619 NY U.S. Environmental Protection Agency Region 2 (U.S. EPA R2). Received

2013. Active Permitted Class II

- D Wells in New York. A

SGE00623 N/A U.S. Government Accountability Office (GAO). 2012. Energy

- Water

Nexus. Information on the Quantity, Quality, and Management of Water Produced During Oil and Gas Production. (January). GAO

- 12

- 156. AMemorandum

M arch 3 1 , 2015 Page 11

Table 1 . References

DCN State Full Citation Source Flag a

SGE00625 N/A US EPA. 201 5 . Site Visit Report Southwestern Energy Fayetteville Shale

Operations. Sanitized. A

SGE00 6 35 N/A US EPA. 2012. Site Visit Report Chesapeake Energy Corporation

Marcellus Shale Gas Operations Sanitized. A

SGE00693. A 0 3 N/A ERG. 201 5

. Data Compilation Memorandum for the Technical

Development Document (TDD) for Proposed Effluent Limitations Guidelines and Standards for Oil and Gas Extraction

- Attachment 3: TDD Data Compilation A

SGE00704 N/A U.S. Environmental Protection Agency (U.S. EPA). 2015. Technical

Development Document for Proposed Effluent Limitations Guidelines and Standards for Oil and Gas Extraction. A

SGE00770 IL Shutt, Doug. 2014. Email Correspondence between IL Office of Oil and

Gas Resource Management and EPA. (May 30). A

SGE00957 NA Eastern Research Group, Inc. 2013. Environmental Engineering Support for

Clean Water Regulations Programmatic Quality Assurance Project Plan (PQAPP)

. October 1

. A

SGE00958 NA Eastern Research Group, Inc. 2014. Unconventional Oil and Gas (UOG)

Supplemental Quality Assurance Project Plan (SQAPP)

. August 15. A

SGE00959 AK Alaska Oil and Gas Conservation Commission. 2014. AOGCC Data Extract

Zip File

. (April 8). A

SGE00960 AK Alaska Oil and Gas Conservation Commission. 2014. AOGCC Data Extract

Zip File Table Description

. (April 8). A

SGE01012 Multiple U.S. EPA. 2014

. Class II Disposal Inventory in EPA Direct Implementation

Programs . Data as of 3/31/20 1 4. A

SGE01014 OK Oklahoma Corporation Commission (OCC). 201 5 . UIC Injection Volumes

201 2. Downloaded on 2/5 /201 5 . Available online at: http://www.occeweb.com/og/ogdatafiles2.htm. A

SGE01015 OK Oklahoma Corporation Commission (OCC). 2014. Well_Status.

Downloaded on 12/18/2014. Available online at: http://www.occeweb.com/og/ogdatafiles2.htm. A

SGE01089 OK Murray, Kyle. 2014. Class II Underground Injection Control Well Data for

2010

– 2013 by Geologic Zones of Completion, Oklahoma. Oklahoma Geological Survey Open

- File Report (OF1

- 2014). Norman, OK. Pp. 32. A

SGE01109 PA/VA U.S. EPA. 2015. PA and VA Class II Injection for Disposal Volume Data. A
SGE01110 WV Sminchak, John; Miller, John. Gupta, Neeraj. 2015. Brine Disposal

Reservoirs in the Appalachian Basin: Injection Performance and Geological Properties. ( February 9

- 11). B

a

— Source Flag A

— J ournal articles and documents prepared by or for a government agency (e.g., site visit reports, industry meeting notes). Source Flag B

— Documents prepared by a verified source that include citation information (e.g., operator reports, vendor documents, university publications). Source Flag C

— Documents prepared by a verified source that do not include citation information (e.g., operator reports, vendor documents, conference presentations). Source Flag D

— Documents prepared by a source that could not be verified and that do not include citation information.Memorandum

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A NALYSIS E XCEL F ILE ( DCN SGE 00736.A 0 1)