MEMORANDUM

TO: Lisa Biddle, U.S. EPA

FROM: Brent Ruminski, ERG

Sarah Yates, ERG

DATE: June 7, 2016

SUBJECT: Data Compilation Memorandum for the TDD (DCN SGE001179)

This memorandum describes how ERG developed various tables and figures presented in

EPA’s Technical Development Document for Effluent Limitations Guidelines and Standards for 

Oil and Gas Extraction (TDD) (DCN SGE01188). Specifically, this memorandum focuses on the 

tables and figures listed in Table 1 of this memorandum all of which are specific to 

unconventional oil and gas (UOG) extraction. TDD tables and figures not listed in Table 1 either 

did not require calculations and/or analyses by ERG or are described in separate, supporting 

memoranda. The Crosswalk Memorandum between Proposed and Final Technical Development 

Document for Effluent Limitations Guidelines and Standards for Oil and Gas Extraction: Tables 

and Figures (DCN SGE01334) contains a crosswalk of all tables and figures in the TDD. 

Appendix F of the TDD contains the name of the relevant supporting memorandum for each 

TDD table and figure, where applicable. This memorandum is organized into the following 

sections:

 Section 1.0 discusses tables and figures in the TDD Chapter B, Scope and 

Industry Description.

 Section 2.0 discusses tables and figures in the TDD Chapter C, Unconventional 

Oil and Gas Extraction Wastewater Volumes and Characteristics.

 Section 3.0 discusses tables and figures in the TDD Chapter D, Unconventional 

Oil and Gas Extraction Wastewater Management and Disposal Practices.

 Section 4.0 describes ERG’s quality assurance procedures.

 Section 5.0 lists the references used for these analyses.

For those figures/tables ERG generated specifically for this memorandum, the underlying 

data and analysis are contained in: 

 Attachment 1 – Onshore Oil and Gas Drilling Activity - DCN SGE001179.A01

 Attachment 2 – EIA UOG Resource Potential - DCN SGE001179.A02

 Attachment 3 – TDD Data Compilation - DCN SGE001179.A03

For the tables/figures explained in more detail in this memorandum, Table 1 provides the 

TDD chapter, memorandum section, and attachment information. 
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 2

Table 1. List of Tables and Figures Discussed in this Memorandum

TDD

Chapter

TDD Table 

or Figure 

Number TDD Table or Figure Title

Memo.

Section

Memo.

Attachment 

DCN

B

Figure B-7

Length of Time to Drill a Well in Various UOG 

Formations (2012 through 2014) 1.1 SGE001179.A01

Figure B-13 Number of Active U.S. Onshore Rigs by Trajectory and 

Product Type over Time 1.2 SGE001179.A01

Table B-2

Active Onshore Oil and Gas Drilling Rigs by Well 

Trajectory and Product Type (as of October 9, 2015)

1.2 SGE001179.A01

Table B-3

a UOG Potential by Resource Type as of January 1, 2013 1.3 SGE001179.A02

Table F-3

b UOG Resource Potential: Shale as of January 1, 2013 1.3 SGE001179.A02

Table F-4

b UOG Resource Potential: Tight as of January 1, 2013 1.3 SGE001179.A02

Figure B-14 Projections of UOG Well Completions 1.4 SGE001179.A03

C Table C-1 Sources for Base Fluid in Hydraulic Fracturing 2.0 SGE001179.A03

D

Table D-1 UOG Produced Water Management Practices 3.1 SGE001179.A03

Table D-5 Reported Reuse/Recycle Criteria 3.2.1 SGE001179.A03

Table D-6

Reported Reuse/Recycle Practices as a Percentage of Total 

Fracturing Volume 3.2.2 SGE001179.A03

Figure D-9

Hypothetical UOG Produced Water Generation and Base 

Fracturing Fluid Demand over Time 3.2.3 SGE001179.A03

a—This table in the TDD also includes some data from a separate ERG analysis (Analysis of DI Desktop®

Memorandum, DCN SGE01180).

b—These tables are related to the discussion about Table B-3 in Chapter B of the TDD.

For definitions of common terms used throughout the TDD, the supporting memoranda, 

and memoranda attachments, please refer to the Glossary in the introduction of the TDD.

1.0 COMPILATION OF DATA FOR TDD CHAPTER B

The following subsections discuss the data and methods used to develop the tables and 

figures listed in Table 1 and presented in TDD Chapter B. 

1.1 TDD Chapter B, Section 2.1 UOG Well Drilling and Construction (Figure B-7)

Figure B-7 “Length of Time to Drill a Well in Various UOG Formations” shows the 

number of days required to drill a well in various UOG formations. Attachment 1 (DCN 

SGE001179.A01) contains the underlying data in the tabs called “Drilling Days Data” and 

“Drilling Days Figure”. For this analysis, ERG obtained data from Baker Hughes’ U.S. Onshore 

Well Count (DCN SGE01234). This dataset is a quarterly census of the number of new onshore 

oil and gas wells that were spud1in the U.S., and includes counts of the number of land wells, 

the number of land rigs, and the number of land wells per rig that were spud in each major U.S. 

 

1 The term “spud” means to initiate the drilling of a well.
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 3

basin/formation2. These counts are available from first quarter 2012 through fourth quarter 2014, 

and are representative of all U.S. oilfield activities. 

To calculate the average time to drill a well in each formation presented in TDD Figure 

B-7, ERG divided the number of days in each quarter (typically 91 or 92 days) by the number of 

wells per rig for that quarter to calculate drilling efficiency, or the average number of drilling 

days per well per rig in a given UOG basin/formation. 

For simplicity, ERG combined the well counts for the three different Woodford shale 

formations (i.e., Ardmore Woodford, Arkoma Woodford, Cana Woodford) to represent the 

Woodford shale formation. ERG accomplished this by summing the well counts and rig counts 

respectively for each quarter for the three different Woodford shale formations. ERG then 

performed the final calculation described above using the new, combined Woodford shale totals 

to get the number of drilling days per rig. 

1.2 TDD Chapter B, Section 3.1 Historical and Current Drilling Activity for 

Unconventional Oil and Gas (Figure B-13 and Table B-2)

Baker Hughes periodically publishes the two active rig count datasets3listed below that 

provide different and more detailed information on active wells than the Baker Hughes U.S. 

Onshore Well Count dataset (DCN SGE01234) described in Section 1.1. ERG downloaded these 

two additional rig count datasets in October 2015 and used them as the basis for Figure B-13 and 

Table B-2 in the TDD. Attachment 1 (DCN SGE001179.A01) contains the downloaded rig count

datasets and ERG’s analyses. Information contained in these two Baker Hughes datasets are 

described below. 

 North America Rotary Rig Count (Jan 20004- Current) (DCN SGE01235): tabulates the 

total number of active rigs in the U.S. and Canada for each week dating back to January 

1991 and indicates product type (i.e., oil, gas, mis5) and well trajectory (i.e., horizontal, 

directional, vertical). The dataset includes the following fields:

 Well Trajectory

 Number of rigs drilling horizontal wells

 Number of rigs drilling directional wells

 Number of rigs drilling vertical wells

 Total number of active rigs

 Product Type

 Number of rigs drilling for oil

 Number of rigs drilling for gas

 Number of rigs drilling for “miscellaneous”

 Total number of active rigs (equals the total number of active rigs in the 

trajectory category above)

 

2Baker Hughes reported a mixture of basins (e.g., Williston, Permian) and formations (e.g., Marcellus, Utica) in all 

of their rig counts datasets.

3 Baker Hughes’s rig count datasets serve as an indicator of demand for products used in drilling, completing, 

producing, and processing hydrocarbons in the petroleum industry.

4 Although this source title includes the phrase “Jan 2000 – Current”, it includes data back to January 1991.

5 Baker lists some wells as “Mis” which stands for miscellaneous. ERG added these types of rigs to oil rig counts for 

all analyses assuming that they represent wells that produce a mixture of oil and gas (i.e., wet gas).
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 4

 North America Rotary Rig Count Pivot Table (DCN SGE01233): presents a record for 

each active rig in North America on a weekly basis beginning in February 2011. The 

dataset includes the following for each rig:

 Country (i.e., Canada, United States);

 County;

 Basin6;

 Drill For (i.e., gas, oil, miscellaneous);

 Location (i.e., land, offshore, inland waters);

 Trajectory (i.e., directional, horizontal, vertical, other);

 Well Type;

 Well Depth;

 Water Depth;

 Date (both publish date and the date the data represents); 

 Rig count (i.e., number of rigs); and

 State/Province. 

The following two subsections describe how ERG used these Baker Hughes datasets to generate 

Figure B-13 and Table B-2 in the TDD.

1.2.1 Figure B-13 “Number of Active U.S. Onshore Rigs by Trajectory and Product 

Type over Time”

Figure B-13 “Number of Active U.S. Onshore Rigs by Trajectory and Product Type over 

Time” shows the estimated total number of active drilling rigs between January 2000 and 

October 2015. The figure also plots the number of drilling rigs by trajectory type (i.e., 

directional, horizontal, vertical) and by well type (i.e., oil, gas). To prepare this figure, ERG

graphed the relevant U.S. data as reported in the Baker Hughes North America Rotary Rig Count

dataset (Jan 2000 - Current)7(DCN SGE01235). Attachment 1 (DCN SGE001179.A01) contains 

the underlying data and analysis for Figure B-13 in the tabs called “Drill Over Time Data

(SGE01235)” and “Drill over Time Figure”.

1.2.2 Table B-2 “Active Onshore Oil and Gas Drilling Rigs by Well Trajectory and 

Product Type (as of October 9, 2015)”

Table B-2 “Active Onshore Oil and Gas Drilling Rigs by Well Trajectory and Product 

Type (as of October 9, 2015)” shows the number of active drilling rigs in the U.S. by basin

and/or formation8. The rig counts are further broken down by well trajectory (i.e., directional, 

horizontal, vertical) and by well type (i.e., oil, gas). To develop Table B-2, ERG used the most 

recent rig counts from the Baker Hughes North American Rotary Rig Count Pivot Table dataset 

 

6 Baker Hughes reported a mixture of basins (e.g., Williston, Permian) and formations (e.g., Marcellus, Utica) in all 

of their rig counts datasets.

7 This document published by Baker Hughes includes drill rig counts for the entire North America but also provides 

separate counts for the United States. ERG used the data reported for the United States which is in the “US Oil & 

Gas Split” tab in DCN SGE001235.

8 Baker Hughes reported a mixture of basins (e.g., Williston, Permian) and formations (e.g., Marcellus, Utica) in all 

of their rig counts datasets.
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 5

downloaded on October 12, 20159. Attachment 1 (DCN SGE001179.A01) contains the 

underlying data and analysis for Table B-2 in the tabs called “Rigs by Basin Data (SGE01233)” 

and “Rigs by Basin Table”.

ERG used the following steps to summarize the rig counts:

1. Filtered the “Rigs by Basin Data (SGE01233)” tab for:

a. “United States” rigs in the Country field

b. “Land” (i.e., onshore) rigs in the Location field

c. “10/9/2015” in the PublishDate field (as downloaded on October 12, 

2015).

2. In the “Rigs by Basin Table” tab, ERG summed the total number of rigs, number of gas 

rigs, and number of oil rigs for each reported basin/formation applying the filters in Step 

1. For each well type (i.e., oil, gas), ERG further categorized the number of oil or gas 

wells by well trajectory (i.e., directional, horizontal, vertical).

Most data provided by Baker Hughes is on a basin/formation basis. Baker Hughes 

reported a mixture of basins (e.g., Williston, Permian) and formations (e.g., Marcellus, Utica) in 

all of their rig counts datasets. ERG distinguished which data reported by Baker Hughes were 

basins and which data were formations. ERG categorized the data by basin and formation, filling 

in the blanks as necessary based primarily on EIA publications that indicate UOG basins and 

formations. For Woodford formations, Baker Hughes published the following sub-formation data

for the Woodford shale: Cana Woodford, Arkoma Woodford, and Ardmore Woodford. ERG 

combined the number of rigs for these into one common formation called “Woodford”.

1.3 TDD Chapter B, Section 4.2 Unconventional Oil and Gas Resource Potential (Table 

B-3, Table F-3 Table F-4)

The following tables in the TDD summarize the total new well potential, estimated 

ultimate recovery (EUR), and technically recoverable resource (TRR) for four resource types 

(i.e., shale gas, shale oil, tight gas, tight oil) and for each known formation (e.g., Marcellus, 

Barnett): 

 Table B-3 - “UOG Resource Potential by Type as of January 1, 2013”.

 Table F-3 - “UOG Resource Potential: Shale as of January 1, 2013”.

 Table F-4 - “UOG Resource Potential: Tight as of January 1, 2013”.

10

To create these tables, ERG used the data reported in Table 9.3 of the U.S. Energy 

Information Administration’s (EIA) Assumptions to the Annual Energy Outlook 2015 (DCN 

SGE01190). Attachment 2 (DCN SGE001179.A02) contains the underlying data and analysis.

In the assumptions to each Annual Energy Outlook (AEO) report, EIA reports the total

resource potential for each active and prospective UOG formation. EIA bases these estimates on 

studies completed by the United States Geological Survey (USGS), historical oil and gas 

production, and expected future advances in drilling technology. The two resource estimates

 

9 The Baker Hughes data was downloaded on 10/12/2015. These data had last been updated by Baker Hughes on 

10/9/2015.

10 Tables F-3 and F-4 are located in Chapter F of the TDD but support Chapter B.
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 6

reported by EIA that ERG used in our analysis are described below.11 The “EIA UOG Potential 

Data” tab in Attachment 2 contains the estimates as reported by EIA.

 Technically Recoverable Resource (TRR) – TRR is the total crude oil12 and/or gas that is 

believed to be extractable from a formation based on current technology disregarding 

economics. In EIA’s 2015 Assumptions report (DCN SGE01190), TRR estimates are 

reported as of January 1, 2013. EIA reports natural gas TRR in units of trillion cubic feet 

(TCF) and crude oil TRR in units of billion barrels (BBbls). ERG converted the natural 

gas TRR from TCF to billion cubic feet (BCF) and the crude oil TRR from BBbls to 

million barrels (MMbbls) before inputting the data in the “EIA UOG Potential Data” tab 

in Attachment 2 (DCN SGE001179.A02). 

 Estimated Ultimate Recovery (EUR) – Lifetime recovery of crude oil, and/or natural gas 

per well based on existing production data and current/expected drilling practices in each 

formation (e.g., vertical or horizontal drilling). These estimates are averages across all 

wells; actual production may vary significantly from well to well. EIA reports natural gas 

EUR in units of BCF per well and crude oil EUR in units MMbbls per well.

ERG used EIA’s TRR and EUR estimates to calculate new well potential by formation 

(e.g., Marcellus) and by resource type (e.g., shale gas, tight oil). ERG calculated the new well 

potential based on EIA’s TRR estimates which assume current oil and gas extraction technology 

(e.g. hydraulic fracturing, horizontal drilling). These estimates do not factor in future changes to 

TRR estimates, advances in drilling technology, or economic conditions that ultimately 

determine how many wells industry drills. 

Specifically, ERG used the following procedures for this analysis: 

1. In the “EIA UOG Potential Data” tab in Attachment 2 (DCN SGE001179.A02), ERG

calculated new well potential for each formation or sub-formation (e.g., Central

Fayetteville, West Fayetteville) reported by EIA using Equation 1.

13 The natural gas and 

crude oil TRR and EUR can be used interchangeably to find the same new well potential

for each formation. A few unconventional oil formations have zero natural gas TRR. For 

these, ERG used the crude oil TRR and EUR to calculate new well potential. Otherwise, 

ERG used the natural gas TRR and EUR to calculate new well potential.

Equation 1

New Well Potential formation (wells) =

TRR formation(BCF)

EUR formation (

BCF

well )

 

11 EIA also publishes the following statistics for each UOG formation: total land area (square miles), percent of land 

area that may be developed (%), and maximum well spacing (wells/square mile). Multiplying these values for a 

given formation provides an estimate of new well potential.

12 EIA’s TRR for crude oil includes the TRR for lease condensates. EIA provides TRR estimates for natural gas 

plant liquids (NGPLs) separately but they were not the focus of ERG’s analysis. EIA defines NGPLs production as 

the extraction of gas plant liquid constituents such as ethane, propane, normal butane, isobutane, and natural 

gasoline, sometimes referred to as extraction loss.

13 ERG calculated the total new well potential using the same method EIA presented in EIA’s Assumptions to the 

Annual Energy Outlook 2015 (DCN SGE01190). 
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 7

2. In the “EIA UOG Potential Data” tab in Attachment 2 (DCN SGE001179.A02), ERG

used engineering judgment to assign each formation and sub-formation (reported by EIA) 

a common formation name. For example, EIA reported resource potential separately for 

“Fayetteville-Central” and “Fayetteville-West.” ERG consolidated these formation names 

into “Fayetteville.” 

3. In the “EIA UOG Potential Data” tab in Attachment 2 (DCN SGE001179.A02), ERG 

classified each formation and sub-formation into one of four resource types: shale gas, 

shale oil, tight gas, or tight oil. For most formations, ERG used the resource types 

assigned to formations by EIA in their shale formation map (DCN SGE01191), their tight 

formation map (DCN SGE00155), and their Assumptions to the Annual Energy Outlook 

2013 (DCN SGE00486).

14 However, all unconventional oil formations were combined by 

EIA in this report into the group called “tight oil” which includes both shale and tight 

formations. Therefore, ERG assigned each unconventional oil play to either the shale oil 

or tight oil category as shown in EIA’s shale and tight maps (DCN SGE01191 and DCN 

SGE00155).15

4. In the “Potential Data by Formation” tab in Attachment 2 (DCN SGE001179.A02), ERG 

used Equation 2 and Equation 3 below to recalculate total new well potential and TRR 

for each consolidated formation in order to eliminate sub-formations from the list. ERG 

calculated the average EUR for each consolidated formation using Equation 4 and the 

results from Equation 2 and Equation 3. The results of this step generate Table F-3 and F4 in the TDD.

Equation 2

TRR formation (BCF) = ∑TRR sub−formations (BCF)

Equation 3

New Well Potential formation(wells) = ∑New Well Potential sub−formations (wells)

Equation 4

Average EUR formation (

BCF

well) =

TRR formation(BCF)

New Well Potentialformation(wells)

5. In the “Potential Data by Resource Type” tab in Attachment 2 (DCN SGE001179.A02), 

ERG used Equation 5 and Equation 6 below to recalculate total TRR and total new well 

potential for each of the four resource types that were assigned by ERG in Step 3, above.

Next, ERG calculated the weighted average EUR for each resource type using Equation 7

and the results from Equation 5 and Equation 6. The results of this step generate Table B3 in the TDD.

Equation 5

TRR resource type(BCF) = ∑TRRformations (BCF)

 

14 EIA’s 2015 assumptions report (DCN SGE01190) did not organize the list of UOG formations by resource type 

but the 2013 version of the report (DCN SGE00486) did.

15 A few formations did not appear in EIA’s 2013 assumptions report or in the EIA shale and tight maps. ERG used 

assessment reports completed by the USGS to assign the appropriate resource type to these formations.
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 8

Equation 6

New Well Potential resource type (wells) = ∑New Well Potential formations (wells)

Equation 7

Weighted Average EUR resource type (

BCF

well) =

TRR resource type(BCF)

New Well Potential resource type(wells)

Table B-3 also shows estimates of active UOG wells during 2013 – 2015. ERG obtained 

these estimates using data from Drillinginfo’s (DI) Desktop® well database described in a 

separate memorandum, Analysis of DI Desktop® Memorandum (DCN SGE01180).

1.4 TDD Chapter B, Section 3.3 Current and Projections of Future UOG Well 

Completions (Figure B-14)

Figure B-14 “Projections of UOG Well Completions” shows the projected number of 

UOG wells completed annually and cumulatively using information from the October 2012 IHS 

Report, America’s New Energy Future: The Unconventional Oil and Gas Revolution and the US 

Economy (DCN SGE00864). Attachment 3 (DCN SGE001179.A03) contains the underlying data 

and analysis in the tabs called “IHS Well Projections” and “IHS Well Projections Figure”.

IHS estimated annual well completions for 2012, 2015, 2020, 2025, 2030, and 2035. IHS 

estimates are provided for unconventional oil wells and unconventional gas wells.16 For gas 

wells, IHS estimates are further broken down by resource type (i.e., shale, tight). ERG

extrapolated the number of well completions between the years reported by IHS. For example, 

IHS reported 7,179 unconventional oil well completions in 2012 and 8,472 completions in 2015, 

or an increase of 1,293 unconventional oil wells over this three-year period. Therefore, ERG

assumed that 431 unconventional oil wells are completed each year from 2012 to 2015. 

Using the number of wells completed each year (either reported by IHS or extrapolated 

from IHS data); ERG calculated the cumulative well completions by summing the number of 

completed wells for that year and all preceding years starting in 2012. 

2.0 COMPILATION OF DATA FOR TDD CHAPTER C, SECTION 1.1 BASE FLUID 

COMPOSITION (TABLE C-1)

TDD Table C-1 “Sources for Base Fluid in Hydraulic Fracturing” shows the composition 

of base fluid used for hydraulic fracturing across major basins and various UOG formations. 

Attachment 3 (DCN SGE001179.A03) contains the underlying data references and analysis in 

the tab called “Base Fluid Data”. For some basins/formations, ERG identified data from multiple 

references and/or projected17 data in addition to historic year data. Therefore, each formation 

may have multiple rows in this tab where each row represents the various references and types of 

data (i.e., historic or projected). In addition, literature reported various types of sources that are 

 

16 IHS uses the same definition of UOG as defined in this memorandum.

17 ERG identified one report that projected base fluid composition for “low water use”, “most likely”, and “high 

water use” scenarios for 2020 and 2060. ERG used the “most likely” scenario for 2020 (DCN SGE00639).
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 9

used for base fluid. ERG categorized the reported data from the source into one of three 

categories in the “Base Fluid Data” tab:

 Fresh water – Naturally occurring water on the Earth's surface. Examples include 

ponds, lakes, rivers and streams, and certain underground aquifers. Fresh water is 

generally characterized by having low concentrations of dissolved salts and other 

total dissolved solids (TDS).

 Brackish water – Water that has more salinity than fresh water, but not as much as 

seawater. Example sources include certain underground aquifers, effluent from 

publicly owned treatment plants (POTWs), and wastewater from other industries.

 Reuse/recycle water – This is any UOG extraction wastewater (i.e., flowback, longterm produced water, drilling wastewater). 

To populate Table C-1 in the TDD, ERG compiled percentages from the “Base Fluid 

Data” tab in the “Base Fluid Summary” tab on a basins/formations basis. For basins/formations 

where ERG identified projected data in addition to historic data, ERG created a separate set of 

columns for each basin/formation combination in the tab. Table C-1 presents these projected data 

parenthetically.

3.0 COMPILATION OF DATA FOR TDD CHAPTER D

The following subsections discuss the data and methods used to develop tables and 

figures listed in Table 1 and presented in TDD Chapter D. 

3.1 TDD Chapter D, Introduction (Table D-1)

Table D-1 “UOG Produced Water Management Practices” presents information about 

how UOG operators manage produced water across basins containing major UOG formations.

ERG reviewed existing literature sources for information about wastewater management 

practices. Some sources only contained qualitative produced water management information, 

while others also reported the percentage of produced water disposed of via each management 

practice. Because quantitative data were not available across all formations, ERG categorized

management practices in each formation as follows: 

 X – A small (<10 percent) or unknown portion of UOG produced water was managed 

with this management practice; 

 XX – A moderate portion (>10 and <50 percent) of UOG produced water was managed 

with this management practice; or 

 XXX – A majority (>50 percent) of UOG produced water was managed with this 

management practice. 

The “UOG PW Management” tab in Attachment 3 (DCN SGE001179.A03) contains the 

underlying data references used to create Table D-1. The attachment includes additional 

information that is not included in the TDD about how ERG designated the “X” categories. The 

“Additional Comments” column provides further explanation about the type of information 

reported in the underlying reference that ERG used to assign the “X” category.
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 10

3.2 TDD Chapter D, Section 3.2 Reuse/Recycle Drivers (Table D-5, Table D-6, and 

Figure D-9)

The following subsections describe how ERG used existing literature to generate Table 

D-6, Table D-6 and Figure D-9 in the TDD.

3.2.1 Reuse Criteria

Table D-6 “Reported Reuse/Recycle Criteria” shows ranges of observed or recommended 

constituent concentrations for use in fracturing base fluid (i.e., mixture of wastewater and other 

source water). It also shows the associated potential issue that the fluid or well may experience 

with concentrations in excess of that concentration. Attachment 3 (DCN SGE001179.A03)

contains the underlying data and analysis in the tabs called “Reuse Criteria Data” and “Reuse 

Criteria Summary”.

ERG compiled the reported criteria (in units of mg/L, c/mL, or S.U.) for each constituent 

from existing literature. From these compiled values, ERG calculated the minimum and 

maximum reported criteria (i.e., concentrations) for each constituent. In addition to the 

concentration criteria, ERG presented the associated potential issue that the fluid or well may 

experience, as reported in Acharya et al., 2011 (DCN SGE00070), in Table D-5 in the TDD.

3.2.2 Reuse Drivers at the Well Level

Table D-6 “Reported Reuse/Recycle Practices as a Percentage of Total Fracturing 

Volume” presents the volume of reused/recycled wastewater as a percent of the total base fluid 

volume used to fracture a specific well, or the blending ratio, for several different formations. 

Table D-6 reports the actual blending ratio and/or the estimated maximum potential blending 

ratio reported in literature (e.g., technical presentation from an industry conference). To generate 

this table, ERG only used literature where UOG operators or industry experts were the author.

The estimated maximum potential blending ratio was described in literature as the typical 

flowback volume per well compared to the typical fracturing volume per well.

Attachment 3 (DCN SGE001179.A03) contains the underlying data and analysis in the 

“Reuse Blending Ratios Data” and “Reuse Blending Ratios Summary” tabs. In the “Reuse 

Blending Ratios Data” tab, ERG tabulated actual reuse percentages and estimated maximum 

reuse potential on a basin and formation basis based on values reported in existing literature. 

ERG calculated the minimum and maximum values within each category (i.e., actual blending 

ratio and estimated potential blending ratio) by basin and formation and presented the resulting 

range in the “Reuse Blending Ratio Summary” tab and Table D-6 in the TDD.

3.2.3 Reuse Drivers at the Formation Level

Figure D-9 “Hypothetical UOG Produced Water Generation and Base Fracturing Fluid 

Demand over Time” illustrates a hypothetical scenario for UOG produced water generation. This 

figure indicates that, as a formation matures, the volume of base fluid needed to fracture 

subsequent wells may be less than the volume of produced water generated by producing wells 

in the area. This figure was regenerated from a wastewater disposal figure presented in Shell 

Canada Limited’s October 29, 2012 presentation, “Identifying the Recycling and Treatment 

Criteria that Must be Met to Avoid Scaling and Enable Successful Re-Use” (DCN
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 11

SGE00305.A03). The scenario is for one operator in a particular formation based on a 

hypothetical drilling program. ERG regenerated this figure by interpreting values of “wastewater 

generation” and “demand for fracturing” from the figure in the Shell presentation. Attachment 3 

(DCN SGE001179.A03) contains the estimated volumes derived from the Shell presentation, 

which were used as the underlying data for Figure D-9 in the TDD, in the “Hypothetical 

Scenario Data” and “Hypothetical Scenario Figure” tabs.

4.0 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.

Specifically, ERG used the procedures described in Section 4 of the PQAPP to gather and 

manage existing data in support of the UOG 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 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. As shown in Table 2 in this 

memorandum, ERG assigned a source flag (A, B, C or D) to all references used in these 

analyses. ERG defines each source flag as follows: 

 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 source18 that include citation 

information (e.g., operator reports, vendor documents, conference presentations, 

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.

EPA and 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 three Microsoft Excel spreadsheets provided in Attachments 1

through 3 to track useful data and to document analyses. ERG performed a 100 

 

18 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
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 12

percent check of all data entry, manipulations and calculations, and documented 

these in an internal version of the spreadsheet.

 ERG had a senior staff member familiar with ELGs and the UOG rulemaking 

review the results from the three Microsoft Excel spreadsheets provided in 

Attachments 1 through 3.

5.0 REFERENCES

Table 2 provides DCNs, citations, and source flags for references used in these analyses. 

The references in Table 2 are sorted by DCN.

Table 2. References

DCN Source Citation 

Source 

Flaga

SGE00007.A10 Mantell, Matthew, Chesapeake Energy Corp. 2011. Produced Water Reuse and 

Recycling Challenges and Opportunities Across Major Shale Plays

B

SGE00070 Acharya, Harish; Matis, Hope; Kommepalli, Hareesh; Moore, Brian; Wang, Hua. 

2011. Cost Effective Recovery of Low-TDS Frac Flowback Water for Re-use. 

A

SGE00090 NYSDEC. 2011. Suppl. Generic Env. Imp. Statement on Oil, Gas, & Soln. Mining 

Reg. Prgm. Prelim. Rev. Draft.

A

SGE00091 Rimassa, Shawn; Howard, Paul; Blow, Kristel; Schlumberger. 2009. Optimizing 

Fracturing Fluids from Flowback Water. Society of Petroleum Engineers.

A

SGE00092 ALL Consulting. 2004. Coal Bed Methane Primer. US DOE. A

SGE00093 Veil, John et. al. 2004. A White Paper Describing Produced Water from Production of 

Crude Oil, Natural Gas, and Coal Bed Methane. By Argonne Nati Lab

A

SGE00094 Journal of Environmental Law and Litigation, Volume 17(2) B

SGE00095 URS. 2011. Water-Related Issues Associated with Gas Production in the Marcellus 

Shale. (March 25).

B

SGE00096 Sumi, Lisa. 2008. Shale Gas: Focus on the Marcellus Shale. Oil and Gas 

Accountability Project / Earthworks.

B

SGE00155 U.S. Energy Information Administration. 2010. Tight Sands Gas Plays, Lower 48 

States. Prepared by EIA Office of Oil and Gas. (June).

A

SGE00254 MI DEQ. 2006. MI Oil and Gas Regulations: Natural Resources and Environmental 

Protection Act—No. 451 of the Public Acts of 1994. (April)

A

SGE00275 U.S. EPA. 2012. Site Visit Report: Citrus Energy Corporation Marcellus Shale Gas 

Operations. (January 22).

A

SGE00276 U.S. EPA. 2012. Meeting with XTO Energy, Inc. about Unconventional Oil and Gas 

Sanitized.

A

SGE00284 Hayes, Thomas et al. 2012. Barnett and Appalachian Shale Water Management and 

Reuse Technologies. RPSEA

A

SGE00298.A23 Robie Cathey. 2012. Ecosphere. Ecosphere Tech. B

SGE00305.A03 Cheung, Timothy. 2012. Identifying the Recycling and Treatment Criteria That Must 

be Met to Avoid Scaling and Enable Successful Reuse. Shell.

C

SGE00311.A12 Mark Mazoch. 2012. Fayetteville Shale. Southwestern Energy. B

SGE00339 Susquehanna River Basin Commission (SRBC). 2011. Susquehanna River Basin 

Commission: Water Withdrawals & Consumptive Use for Natural Gas Industry.

A
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 13

Table 2. References

DCN Source Citation 

Source 

Flaga

SGE00341 John A. Veil. 2011. Water Management Practices Used by Fayetteville Shale Gas 

Producers. Argonne Nat'l Lab and US Dept of Energy Natl Energy Tec Lab

A

SGE00379 Hill, David A. 2012. The Future Is NOW for Water Recycling in the Niobrara. 

Wyoming Energy News.

C

SGE00422 James Werline. 2011. Water Requirements and Sustainable Sources in the Barnett 

Shale. Devon Energy.

B

SGE00480 Richard Luedecke. 2012. Energy Water Conservation & Recycling 33rd Annual 

Governor's Water Conference. Devon Energy.

C

SGE00486 U.S. Energy Information Administration. 2013. Assumptions to the Annual Energy 

Outlook 2013.

A

SGE00507 Boschee, Pam. 2012. Handling Produced Water from Hydraulic Fracturing. Oil & 

Gas Facilities.

B

SGE00507 Boschee, Pam. 2012. Handling Produced Water from Hydraulic Fracturing. Oil & 

Gas Facilities.

B

SGE00521 ERG. 2012. Camp, Meghan; Ruminski, Brent. Notes for Shale Gas Industry Meeting 

Held on 29 February 2012. (April 20).

A

SGE00532 Hansen, E; Mulvaney, D; Betcher, M. 2013. Water Resource Reporting and Water 

Footprint from Marcellus Shale Development in WV and PA. (October 30).

B

SGE00556 Nicot, Jean-Philippe, et al. 2011. Current and Projected Water Use in the Texas 

Mining and Oil and Gas Industry. 

A

SGE00575 Petroleum Equipment Suppliers Association (PESA). 2012. Outlook for Domestic 

Unconventional Resources. Presentation at PESA Annual Meeting.

B

SGE00616 U.S. EPA. 2013. Summary of the Technical Workshop on Wastewater Treatment and 

Related Modeling. (April 18)

A

SGE00625 U.S. EPA. 2015. Site Visit Report: Southwestern Energy Fayetteville Shale Gas 

Operations. Sanitized.

A

SGE00637.A05 Vidic, Radisav. 2013. Reuse of Produced Water For Hydraulic Fracturing. B

SGE00639 Nicot et al. 2012. Oil & Gas Water Use in Texas: Update to the 2011 Mining Water 

Use Report. Univ of TX at Austin. (September)

A

SGE00691 U.S. EPA. 2013. Summary of the Technical Workshop on Water Acquisition 

Modeling: Assessing Impacts Through Modeling and Other Means. (September).

A

SGE00705 ERG. 2014. Ruminski, Brent. Notes on Call with Hydrozonix, LLC on 7 February 

2014. (March 7.)

A

SGE00721 U.S. EPA. 2015. Analysis of Hydraulic Fracturing Fluid Data from the FracFocus 

Chemical Disclosure Registry 1.0. (March).

A

SGE00728 IHS. 2012. America’s New Energy Future: The Unconventional Oil and Gas 

Revolution and the US Economy. Volume 1: National Economic Contributions.

B

SGE00738 Livingston, Doug. 2013. Water Recycling: The Cure for Drillers' Drinking Problem? 

Shale Magazine.

B

SGE00864 IHS. 2012. America’s New Energy Future: The Unconventional Oil and Gas 

Revolution and the US Economy. October 2012. 

B

SGE00957 ERG. 2013. Environmental Engineering Support for Clean Water Regulations 

Programmatic Quality Assurance Project Plan (PQAPP).

A
Data Compilation Memorandum for the TDD 

June 7, 2016

Page 14

Table 2. References

DCN Source Citation 

Source 

Flaga

SGE00958 ERG. 2014. Unconventional Oil and Gas (UOG) Supplemental Quality Assurance 

Project Plan (SQAPP).

A

SGE00966 CCST. 2014. Advanced Well Stimulation Technologies in California: An 

Independent Review of Scientific and Technical Information.

A

SGE00991 USGS. 2008. Assessment of Undiscovered Oil and Gas Resources of the Permian 

Basin Province of West Texas and Southeast New Mexico.

A

SGE00992 United States Geological Survey. Unknown. Woodbine Formation. Accessed on 

10/21/2014.

A

SGE00993 United States Geological Survey. Unknown. Buda Formation. Accessed on 

10/21/2014.

A

SGE01178 ERG. 2016. Analysis of Centralized Waste Treatment Facilities (CWTs) Accepting 

UOG Extraction Wastewater.

A

SGE01180 ERG. 2016. Analysis of DI Desktop® Database. A

SGE01182 ERG. 2016. Analysis of Pennsylvania Department of Environmental Protection’s Oil 

and Gas Waste Reports.

A

SGE01188 U.S. EPA. 2016. Technical Development Document for Proposed Effluent 

Limitations Guidelines and Standards for Oil and Gas Extraction.

A

SGE01190 U.S. Energy Information Administration. 2015. Assumptions to the Annual Energy 

Outlook 2015.

A

SGE01191 U.S. Energy Information Administration. 2015. Lower 48 States Shale Plays. 

Prepared by EIA Office of Oil and Gas. (April).

A

SGE01233 Baker Hughes. 2015. North America Rotary Rig Count Pivot Table (Feb 2011–

Current). (October 9). Downloaded on 10/12/2015.

B

SGE01234 Baker Hughes. 2015. U.S. Onshore Well Count. (January 9). Downloaded on 

10/12/2015.

B

SGE01235 Baker Hughes. 2015. North America Rotary Rig Count (Jan 2000–Current). (October 

9). Downloaded on 10/12/2015.

B

SGE01334 ERG. 2016. Memorandum Providing a Crosswalk between Tables and Figures in the 

Proposed and Final Technical Development Document for Effluent Limitations 

Guidelines and Standards for Oil and Gas Extraction.

A

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, conference presentations, 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.
ATTACHMENT 1: ONSHORE OIL AND GAS DRILLING ACTIVITY EXCEL FILE (DCN

SGE001179.A01)
ATTACHMENT 2: EIA UOG POTENTIAL EXCEL FILE (DCN SGE001179.A02)
ATTACHMENT 3: TDD DATA COMPILATION EXCEL FILE (DCN SGE001179.A03)