MEMORANDUM

TO: Lisa Biddle, EPA

FROM: Brent Ruminski, ERG

Sarah Yates, ERG

DATE: March 31, 2015

SUBJECT: Analysis of Active Underground Injection for Disposal Wells (DCN 

SGE00736)

1.0 INTRODUCTION

An injection 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 gas1industry are described in Section D.2 of the Technical Development Document for 

Proposed Effluent Limitations Guidelines and Standards for Oil and Gas Extraction (DCN 

SGE00704) (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;

 Enhanced recovery wells; and

 Disposal wells.

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

The use of enhanced recovery wells involves the injection of produced water, brine, salt 

water, water, steam, polymers, or carbon dioxide into oil-bearing formations to recover residual 

oil and—in some limited applications—natural gas.2Injected fluid can move through permeable 

formations to decrease the viscosity or displace small amounts of extractable oil and gas, which 

then becomes less resistant 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 fissures in the rock formations, giving 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 (11th 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 hydraulically fractured within the context of this 

memorandum.
Memorandum

March 31, 2015

Page 2

and gas production wells. These production wells bring oil and gas to the surface, 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 Class II enhanced recovery well (DCN 

SGE00613; DCN SGE00623; DCN SGE00132). According to communication with industry, this 

configuration is not possible in unconventional formations because injected fluids cannot readily 

flow through the low permeability formation (DCN SGE00613).

The use of disposal wells involves the injection 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 

during 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 broken 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 the 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., 

conventional, CBM, UOG) can be disposed of in Class II disposal wells. The leading method of 

UOG extraction wastewater management throughout the U.S. is injection into a Class II disposal 

well (DCN SGE00693.A03). Furthermore, 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 SGE00635; 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 quality standard. States may impose additional requirements for management of drilling site stormwater. 
Memorandum

March 31, 2015

Page 3

This memorandum documents the calculations and analyses ERG performed to support 

the information on Class II disposal wells that is presented in Section D.2 in the TDD. This 

memorandum is organized into the following sections:

 Section 2.0 describes the general methodology that ERG used to tabulate the data 

in Table 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 that 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 SGE00736.A01).

2.0 GENERAL METHODOLOGY

Table D-2 in the TDD (DCN SGE00704) contains three types of data related to injection 

for disposal wells, on a state-by-state basis:

 Number of Active Disposal Wells (2011-2014)

 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.A01) 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 meaningful 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.A01) 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 tabulated the number of active 

disposal wells using the data for this analysis. ERG primarily used state agency oil and gas 

databases to identify the number of active Class II disposal wells. Most state databases provide 

active well counts for the 2012 to 2014 time frame5and 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 determine 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.

5A 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 data. 
Memorandum

March 31, 2015

Page 4

were well status and well type. ERG documented the specific filters applied for each state dataset 

within the Well Count Documentation tab. ERG included Class 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 published 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.6In 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 was unclear if the state databases 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.A01) 

documents how ERG calculated 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)7of oil and gas produced 

water sent to injection for disposal wells in each state as documented in 

Attachment 1 (DCN SGE00736.A01). For as many states as possible (10 states), 

this value was obtained from the same state agency reference used to identify the 

number of active Class 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 (14 states), these volume data were obtained from Argonne 

National Laboratory’s (ANL) 2009 report titled Produced Water Volumes and 

Management in the United States (DCN SGE00182).8This 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 average disposal rate per well (gpd/well) by 

dividing the total annual volume (barrels) by 365 days/year, divided by the 

number of disposal wells active in the same year, and multiplied 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 report also relied on state oil and 

gas agencies to estimate state level disposal well counts and volumes.
Memorandum

March 31, 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 extraction11, for each state, ERG calculated the state disposal rate (MGD) 

using Equation 1.

Equation 1

 

 

 

 

 

 

Where,

N = Number of active disposal wells identified using methodology in Section 2.1

DRavg = Average disposal rate per well (gpd/well) using methodology in Section 0

The Summary of Results tab in Attachment 1 (DCN SGE00736.A01) contains this 

calculation. As explained in Sections 2.1 and 0, respectively, the active disposal well counts are 

based primarily on 2012 through 2014 data while the average disposal rates per well (gpd/well) 

are based on 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 SUMMARY OF RESULTS

For each state, the Summary of Results tab in Attachment 1 (DCN SGE00736.A01) 

contains the number of active disposal well counts, average disposal rate per well (gpd/well), and 

state disposal rate (MGD). This tab contains 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 regions 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 combined the EIA “Gulf 

Coast” and “Southwest” regions into one category for this analysis to keep state data for Texas 

and New Mexico together. For each region, ERG sorted the states by highest to lowest state 

disposal rate (MGD). Because ERG used different sources 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 counts 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 Section 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

March 31, 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 active disposal well counts. 

4.0 DATA QUALITY AND ASSUMPTIONS

ERG did not substantiate individual well records within the underlying databases (e.g., 

well-by-well review). However, ERG did compare 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 for 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 well (gpd/well): ERG included all 

wells 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 being 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 from 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 volume data: 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 by the state, it is not in the public record and is not used for official analyses.
Memorandum

March 31, 2015

Page 7

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

nation estimated by this analysis may be an underestimate. These states are 

highlighted red in the Summary of Results tab in Attachment 1 (DCN 

SGE00736.A01).

 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 QUALITY CONTROL PROCEDURES

All of the analyses presented in this memorandum adhered to the Environmental 

Engineering Support for Clean Water Regulations Programmatic Quality Assurance Project 

Plan (PQAPP) (DCN SGE00957) and the Unconventional Oil and Gas (UOG) Supplemental 

Quality Assurance Project Plan (SQAPP) (DCN SGE00958), including collecting, evaluating, 

and analyzing existing data and information about underground injection disposal wells.

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 in 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 source flags (DCN SGE00958):

 Source Flag A - Journal 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 verified14 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 for 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. ERG primarily verified information by looking for company/organization websites that confirmed the 

author’s affiliation with the UOG industry.
Memorandum

March 31, 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 Disposal Well Data spreadsheet provided in 

Attachment 1 (DCN SGE00736.A01) 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 analyses 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 

Disposal Well Data spreadsheet provided in Attachment 1 (DCN 

SGE00736.A01).

 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 SGE00736.A01).

6.0 REFERENCES

Table 1 provides citations for references used in these analyses and their assigned source 

flag. 

Table 1. References

DCN State Full Citation Source Flaga

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.

A
Memorandum

March 31, 2015

Page 9

Table 1. References

DCN State Full Citation Source Flaga

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://reports.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/docs/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-ClassificationCodes.Aspx.

A

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

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 Dakota Department of Environmental & Natural Resources 

(SDDENR). 2012. Explanation of Database Fields and Terms. Downloaded 

on 12/31/2012. Available online at: No longer available.

A
Memorandum

March 31, 2015

Page 10

Table 1. References

DCN State Full Citation Source Flaga

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/LiveData_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-WaterNexus. Information on the Quantity, Quality, and Management of Water 

Produced During Oil and Gas Production. (January). GAO-12-156.

A
Memorandum

March 31, 2015

Page 11

Table 1. References

DCN State Full Citation Source Flaga

SGE00625 N/A US EPA. 2015. Site Visit Report Southwestern Energy Fayetteville Shale 

Operations. Sanitized. A

SGE00635 N/A US EPA. 2012. Site Visit Report Chesapeake Energy Corporation 

Marcellus Shale Gas Operations Sanitized. A

SGE00693.

A03

N/A ERG. 2015. 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 3/31/2014. A

SGE01014 OK Oklahoma Corporation Commission (OCC). 2015. UIC Injection Volumes 

2012. Downloaded on 2/5/2015. 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—Journal 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

March 31, 2015

Page 12

ATTACHMENT 1:

ANALYSIS EXCEL FILE (DCN SGE00736.A01)