RPSEA 

Characterization of Flowback Waters from 

the Marcellus and the Barnett Shale Regions

Report No. 08122-05.09

Barnett and Appalachian Shale 

Water Management and Reuse 

Technologies

Contract 08122-05 

March 16, 2012

 

Principal Investigator Principal Investigator

Thomas D. Hayes, Ph.D.

Coordinator, Environmental

Engineering Solutions

Gas Technology Institute

1700 S. Mount Prospect Rd.

Des Plaines, IL

Blaine F. Severin, Ph.D., P.E.

Senior Process Engineer

Environmental Process Dynamics, Inc.

4117 Spinnaker Ln.

Okemos, MI
LEGAL NOTICE

This report was prepared by the Gas Technology Institute as an account of 

work sponsored by the Research Partnership to Secure Energy for 

America, RPSEA. Neither RPSEA members of RPSEA, the National Energy 

Technology Laboratory, the U.S. Department of Energy, nor any person 

acting on behalf of any of the entities:

a. MAKES ANY WARRANTY OR REPRESENTATION, EXPRESS OR 

IMPLIED WITH RESPECT TO ACCURACY, COMPLETENESS, OR 

USEFULNESS OF THE INFORMATION CONTAINED IN THIS 

DOCUMENT, OR THAT THE USE OF ANY INFORMATION, 

APPARATUS, METHOD, OR PROCESS DISCLOSED IN THIS 

DOCUMENT MAY NOT INFRINGE PRIVATELY OWNED RIGHTS, 

OR

b. ASSUMES ANY LIABILITY WITH RESPECT TO THE USE OF, OR 

FOR ANY AND ALL DAMAGES RESULTING FROM THE USE OF, 

ANY INFORMATION, APPARATUS, METHOD, OR PROCESS 

DISCLOSED IN THIS DOCUMENT. 

THIS IS AN INTERIM REPORT. THEREFORE, ANY DATA, CALCULATIONS, 

OR CONCLUSIONS REPORTED HEREIN SHOULD BE TREATED AS 

PRELIMINARY. 

REFERENCE TO TRADE NAMES OR SPECIFIC COMMERCIAL PRODUCTS, 

COMMODITIES, OR SERVICES IN THIS REPORT DOES NOT REPRESENT 

OR CONSTIITUTE AND ENDORSEMENT, RECOMMENDATION, OR 

FAVORING BY RPSEA OR ITS CONTRACTORS OF THE SPECIFIC 

COMMERCIAL PRODUCT, COMMODITY, OR SERVICE. 
THIS PAGE INTENTIONALLY LEFT BLANK
iv

TABLE OF CONTENTS

Table of Contents............................................................................................................iv

List of Tables................................................................................................................... v

List of Figures..................................................................................................................vi

List of Acronyms and Abbreviations ...............................................................................vii

Executive Summary ........................................................................................................ 1

Introduction ..................................................................................................................... 3

Methods and Procedures ................................................................................................ 4

Results from the Marcellus............................................................................................ 10

Flowback Water Collection Characteristics................................................................ 11

General Chemistry..................................................................................................... 12

Organic Compounds.................................................................................................. 20

Volatile Compounds ............................................................................................... 21

Semi volatile Compounds....................................................................................... 24

Pesticides............................................................................................................... 28

Polychlorinated Biphenyls (PCBs).......................................................................... 28

Metals........................................................................................................................ 28

Results From The Barnett ............................................................................................. 32

Flowback Water Collection Volumes ......................................................................... 32

General Chemistry..................................................................................................... 33

Organic Compounds.................................................................................................. 38

Volatile Compounds ............................................................................................... 39

Semi volatile Compounds....................................................................................... 41

Pesticides............................................................................................................... 43

Polychlorinated Biphenyls (PCBs).......................................................................... 45

Metals........................................................................................................................ 45

Discussion..................................................................................................................... 48

Heavy Metals............................................................................................................. 50

Total Dissolved Solids, Major Cations and Anions .................................................... 50

Implications for Fate and Transport ........................................................................... 54

Conclusions................................................................................................................... 57

References Cited .......................................................................................................... 59

Acknowledgements ....................................................................................................... 61

Appendix A: Field Sampling and Analysis Plan (FSAP) ............................................... 62

Appendix B: Quality Assurance Project Plan (QAPP) .................................................. 63
v

LIST OF TABLES

Table 1. Measurements and Determinations. General Chemistry 7

Table 2. Summary of Methods 9

Table 3: Water Use and Flowback Water Collection Associated with Hydraulic 

Fracturing Completion of Shale Gas Wells

11

Table 4. Summary of Chemical Characteristics of Water Used for Hydraulic 

Fracture

14

Table 5: Range of Results from 1 and 5 Day Samples 15

Table 6: Range of Results from 14 and 90 Day Samples 16

Table 7: Concentration of Total Dissolved Solids in Flowback Water at 19 

Locations (mg/l)

17

Table 8: Total Organic Carbon TOC (mg/l) 19

Table 9: Biochemical Oxygen Demand (BOD mg/l) 20

Table 10: Influent Water Day 0 (minus sand) 22

Table 11: Number of Observations of 70 Volatile Compounds in All 60 Marcellus 

Samples 

23

Table 12: Semi-Volatile Content in 19 Marcellus Influent Samples 25

Table 13: Number of Observations of 116 Semi- Volatile Compounds in all 60 

Marcellus Samples 

27

Table 14: Metals Data in Raw Water and Source Water with Additives 29

Table 15: Metals Data for Marcellus Flowback Days 1 and 5 30

Table 16: Metals Data for Marcellus Flowback Days 14 and 90 31

Table 17: Sample Dates (Days after Fracture) for 5 Sites in the Barnett 32

Table 18: Cumulative Flow (BBL) for 5 Sites in the Barnett 33

Table 19. Summary of Chemical Characteristics of Influent Water Used for 

Hydraulic Fracturing after Additives were Blended

34

Table 20 General Chemical Parameters, Barnett Day 1 and Day 3 35

Table 21: Summary of General Chemistry of Flowback Water Days 5-6 and 10-12 36

Table 22: Salt Concentrations (TDS, mg/l) 37

Table 23: Total Dissolved Carbon Concentrations (TDS, mg/l) 37

Table 24: BOD (TDS, mg/l) 38

Table 25: COD (TDS, mg/l) 38

Table 26: Volatile Organics in the Influent Water Samples 39

Table 27: Summary Volatiles Data; All Site Samples (Days 1-12, Total = 16 

Samples)

40

Table 28: Semi Volatile Compounds in the Influent Water 41

Table 29:Semi-volatiles Data from 16 Site Samples (Days 1-23) All Five Sites 43

Table 30: Summary Pesticide Data 44

Table 31; PCB Data 45

Table 32: Total Metals in Influent Water Samples 46

Table 33: Metals Data in the Barnett Samples 47

Table 34: Total Metals Data Days 5-6 and 10-12 48

Table 35. Comparisons of Median Metals Levels in Shale Gas Waters with 

Municipal Biosolids (Sewage Sludge)

50
vi

LIST OF FIGURES

Figure 1. Salt Concentration and Flowback Water Flow Versus Time from 

Location B 

18

Figure 2: Distribution of Observations for 70 Volatile Organics from 60 Samples 

from the Marcellus

24

Figure 3: Distribution of Observation of Semi Volitales in 60 Marchellus 

FLowback Samples from 19 Sites

26

Figure 4: Number of Detectable and Non-Detectable Tests for Volatile 

Compounds

40

Figure 5: Distribution of Observations of Semi volatile Organics in 16 Site

Samples

42

Figure 6: Median Common Components of Flowback Water from the Marcellus 

Samples

49

Figure 7: Median Observations of Common Contaminants in the Barnett Samples 49

Figure 8: Relative Abundance of Cations in Flowback Waters 52

Figure 9: Relative Abundance of Anions in Flowback Waters 53
vii

LIST OF ACRONYMS AND ABBREVIATIONS

Acronym Definition Acronym Definition

ASWCMC Appalachian Shale Water 

Conservation and 

Management Coalition

PPM Part per million (≈mg/l)

BBL/bbl Barrel (42 gallons) PA-DEP Pennsylvania Department of 

Environmental Protection

BCF Billion Cubic Feet PPB Part per billion (≈μg/l)

BTEX Benzene, Toluene, 

Ethylbenzene, Xylenes

POGAM Pennsylvania Oil & Gas 

Association

Flowback 

Water

The water stream that 

flows from a well in the 

weeks following hydraulic 

fracturing completion

QAPP Quality Assurance Project Plan

Frack Hydraulic Fracture TCF Trillion Cubic Feet

Frac Job Well completion event 

involving hydraulic 

fracturing

TDS Total Dissolved Solids

FSAP Field Sampling and 

Analysis Plan

TPH Total Petroleum Hydrocarbons

mg/l Milligrams per liter PCB Polychlorinated Biphenyl 

Compound

μg/l Micrograms per liter POTW Publicly Owned Treatment 

Works (a Sewage Treatment 

Facility)

MSC Marcellus Shale Coalition WVDEPWest Virginia Department of 

Environmental Protection
1

EXECUTIVE SUMMARY

The hydraulic fracturing of shale for the development of unconventional natural gas 

sources has such great potential that it is often touted as an energy revolution. With all 

the positive economic upside to the development of this resource, detractors to the 

industry question the potential environmental impact of the process. Good water 

management is essential to the economic sustainability of the industry. Unfortunately, 

the public literature is replete with anecdotal evidence. There remains a dearth of 

sound scientific publications on which rational decisions may be made. The purpose of 

this report is help address water management issues by elucidating the chemical nature 

of flowback waters. Hopefully, this knowledge may be used to help develop sustainable 

water management plans. 

This report covers recent sampling of flowback water from 19 sites in the Marcellus 

region of Pennsylvania and West Virginia and 5 sites from the Barnett region of northern 

Texas. The database includes flowback rates, volumes, and chemical analyses of the 

injected water and the recovered flowback water. Chemical analyses include general 

chemical information typically used for drinking water analyses. Additionally, the waters 

were tested for 70 volatile organics, 116 semi-volatile organics, 22 pesticides, PCB’s, 

and 27 metals. The list of chemicals evaluated for this project was co-developed by 

industrial partners, and state environmental agency representatives. 

The data are of interest for a couple of discernable trends, such as increased salts 

(total dissolved solids) and decreased flow with time. The main salt composition 

appears to be sodium chloride. Chloride accounts for more than 93% of the available 

anionic content. Some sulfate (500-1000 ppm range) is present in the Barnett samples, 

but is very low in the Marcellus samples (<100 ppm). Carbonate alkalinity, the main pH 

buffering system in natural waters is quite low (<150 ppm). The commonly observed 

cations are sodium, calcium, barium, strontium, and iron. The low alkalinity and sulfate 

concentrations are keys to understanding the relative abundance of the various cation 

species. They are also keys to understanding the range and capability of 

treatment/reuse options for the prevention of scale build-up. Heavy metals (other than 

iron) are generally either not detected, or in very trace concentrations, and generally far 

less concentrated than levels present in municipal wastewater sludge. 
2

Other components, such as the aromatics such as benzene, toluene, ethyl 

benzene, and toluene (BTEX) and other organic compounds, such as naphthalene, that 

are commonly associated with petroleum sites tend to be present only in low to trace 

concentrations (ug/l to ppm) without a discernable pattern with time. Heavier 

polynuclear aromatic hydrocarbon compounds (PAH’s) --- such as commonly seen in 

petroleum wastewater --- are generally not present in the flowback water, and occur 

occasionally in only very trace concentrations. These compounds are considered by 

the wastewater treatment industry to be highly treatable. Several standard treatment 

methods are available to handle these types of compounds at these low levels.

Compounds that can originate from human sources, such as pyridine and the 

general class of phthalate esters, are found in less than 50% of the samples. 

Methylated phenols are more commonly encountered, but only in concentrations 

between 10 to 100 ppb. Halogenated compounds are rarely encountered. One 

pesticide was detected (<0.05 ppb) in one sample (out of 79) and was likely an error. 

PCB’s were not detected in any samples.

Most of the organic chemical analyses performed resulted in “non-detects.” These 

non-observations are vital to begin the discussion of what “not to look for” when 

performing analyses on shale gas waters. It is important to focus engineering and 

planning resources on the chemistry that is present, and to avoid effort in fruitless 

areas. 
3

INTRODUCTION

The Marcellus shale formation is the largest known shale deposit in the world. It 

overlies much of the Appalachian Basin from West Virginia in the south, to Upstate New 

York in the north, and Ohio to the west. The recoverable reserves of natural gas in the 

Marcellus shale have been estimated at more than 489 trillion cubic feet (Engelder, 

2008). Recent advances in horizontal drilling and multi-stage hydraulic fracturing 

technologies have made sustainable natural gas production viable from otherwise 

uneconomical, unconventional shale reservoirs such as the Barnett, Haynesville, 

Fayetteville, Woodford, et al. These tools and technologies have been successfully 

applied and currently enable the ongoing and the future development of these shales. 

Many of the logistical challenges associated with the development of shale gas 

stem from the large amounts of water associated with the completion and operation of 

shale gas wells that must be transported, stored and disposed of in a manner that is 

protective of human health and the environment. In the course of developing shale gas 

in the Barnett and the Marcellus Shale, thousands of wells will be drilled and completed. 

Hydraulic fracturing (“fracking”) is a necessary step for the completion of each of these 

wells in order to achieve economic well performance in terms of natural gas production. 

This step requires between 1 and 4 million gallons (23,800 and 95,200 bbl) of water for 

successful completion of each well; vertical wells require approximately 1 million gallons 

(23,800 bbl) and horizontal wells require 3-4 million gallons (71,400 to 95,200 bbl) 

(Gaudlip, et al., 2008). 

During a typical “fracK job,” water is pumped downhole while chemicals such as 

friction reducers and various grades of sand are introduced to ensure a successful 

fracture of the shale. Following hydraulic fracturing, a fraction of the water 

(approximately 25%) that was injected is collected over several days resulting in the 

collection of a “flowback” water stream that contains salts, oils and greases, and soluble 

organics (volatile and semi volatile) that accumulated in the water downhole. Flowback 

water also contains low concentrations of chemicals that are introduced during the frack

job which normally include friction reducing polymers, corrosion inhibitors, scale 

inhibitors, and biocides. These additives facilitate the hydraulic fracturing process and 

prevent problems with well operation. 
4

The first steps in identifying effective water management alternatives include an 

effective analysis of the characteristics of the water streams involved in shale gas 

development. The overall objective of this project is to develop an information base on 

the nature and composition of influent water and flowback waters associated with 

completions of shale gas wells in the Marcellus and Barnett Shales. 

METHODS AND PROCEDURES

Upon request to the Marcellus Shale Coalition (MSC), 17 member companies of the 

MSC volunteered 19 locations for the sampling of influent and effluent water streams. 

Two companies provided access to five sites in the Barnett. At each location, a well 

completion was conducted using hydraulic fracturing procedures that involved the 

injection of an influent stream of water and the subsequent collection of flowback water. 

Standard procedures were used to conduct sampling and analysis needed for the 

development of water characterization data. All sampling was performed by the GTI 

subcontractor, URS, following the same standard procedures. All sample analyses 

were performed by a single laboratory, Test America of Pittsburgh, PA. Test America, 

an independent analytical laboratory, provided the appropriate sample containers, 

preservatives and completed the analytical analyses. Test America is certified in West 

Virginia and Pennsylvania. Data tabulation, analysis and information base development 

was provided by the Gas Technology Institute for this effort. 

Details of the methods and procedures used for the collection and analysis of 

samples obtained from each of the 19 locations are found in the Field Sampling and 

Analysis Plan (FSAP) which is located in Appendix A. The Field Sampling and Analysis 

Plan (FSAP) was developed to ensure that the data and information gathered for the 

flowback characterization study was properly collected and documented. 

A major aim of the characterization study was to generate technically sound data. 

To meet this objective a Quality Assurance Project Plan (QAPP) was used to generate 

accurate, precise, representative and complete data; this document is provided in 

Appendix B. The QAPP provided the specific quality assurance/quality control (QA/QC) 

procedures executed during the flowback Characterization Study. 
5

Together, the FSAP and QAPP comprise the Sampling and Analysis Plan (SAP). 

The SAP was designed to meet the following informational goals:

Identify specific constituents of interest (COI) associated with flowback water;

Determine whether hydraulic fracturing additives are a source of COI in the 

management of water associated with shale gas development; and, 

Provide sufficient information for the selection of proper water management and 

disposal techniques.

Prior to initiating the characterization study, the SAP was reviewed by regulatory 

officials from the Pennsylvania Department of Environmental Protection (PADEP) and 

the West Virginia Department of Environmental Protection (WVDEP). 

The original SAP proposed that four (4) grab samples from six (6) vertical or 

horizontal well locations be collected throughout West Virginia and Pennsylvania. The 

following grab samples were proposed: 

One baseline fracturing water sample that includes the fracturing chemicals, 

excluding the sand;

Flowback water samples will be collected on days 1, 5 and 14 of the following the 

fracturing process; and 

Water from an existing producing well at 90 days following hydraulic fracturing.

A similar plan was developed for sites in the Barnett with projected collection on 

days 1, 3, 5, and 10. 

The list of constituents recommended for the characterization study was developed 

from comments received from the PADEP, the WVDEP and members of the 

Appalachian Shale Water Conservation and Management Committee (ASWCMC). 

Because the recommended list of constituents was extremely extensive, it was decided 

that one sample from each site would be completed for the full list of recommended 

constituents. All other samples were collected and analyzed for a subset of these 

constituents, which was designed based on generator knowledge. 

The constituents analyzed also include the 56 parameters currently included on the 

PA-DEP Form 26R instructions. This list of parameters is currently undergoing review 

and changes are being considered given that much has learned since that list was 

initially included on the instruction form. Also, it may be appropriate to address 
6

concerns on a media and program specific basis in lieu of the approach suggested by 

the Form 26R instructions. 

To be consistent with this form, the ASWCMC and MSC modified the sampling 

program to include additional constituents. More locations were also included to assist 

operators meet disposal requirements in newly developed areas. 

Following the first few rounds of sampling, industry identified a data gap with

respect to characterizing the supply water used for fracturing. Supply water is identified 

as the water used for fracturing prior to introducing the fracking additives. 

The updated protocol characterization study called for the collection of five (5) grab 

samples from the each of the locations and expanded the sampling effort to encompass 

19 well locations volunteered by 17 member companies of the Marcellus Shale 

Coalition. The plan for the Barnett samples called for collection of four (4) samples at 

five sites. Table 1 presents the list of all of the constituents of interest (by category) that 

formed the basis for sample analysis. Analytical methods used to perform the various 

determinations are listed in Table 2. 
7

Table 1. Measurements and Determinations. 

General Chemistry

pH

Acidity

Total Alkalinity 

Hardness as CaCO3

Total Suspended Solids

Turbidity

Chloride

Total Dissolved Solids

Specific Conductance

Total Kjeldahl Nitrogen

Ammonia Nitrogen

Nitrate-Nitrite

Nitrite as N

Biochemical Oxygen

Demand

Chemical Oxygen 

Demand

Total Organic Carbon (TOC)

Dissolved Organic Carbon

Oil & Grease (HEM)

Cyanide, Total

Amenable Cyanide

Bromide

Fluoride

Total Sulfide

Sulfate

Total Phosphorus

Total Recoverable

Phenolics

Volatile Compounds

1, 4 - Dichlorobenzene

1, 3 - Dichloropropane

2, 2 - Dichloropropane

1, 1 - Dichloropropene

p - Isopropyltoluene

Naphthalene

n - Propylbenzene

1, 2, 3 - Trichlorobenzene

1, 2, 4 - Trichlorobenzene

1, 2, 4 - Trimethylbenzene

1, 3, 5 - Trimethylbenzene

Benzyl chloride

Isopropylbenzene

2 – Butanone

Methyl tert - butyl ether 

(MTBE)

Xylenes (total)

2 - Chloroethyl vinyl ether

cis - 1, 2 - Dichloroethene

Bromobenzene

n - Butylbenzene

sec - Butylbenzene

tert - Butylbenzene

4 - Chlorotoluene

1, 2 - Dichlorobenzene

1, 3 – Dichlorobenzene

Acetone

Acrolein

Acrylonitrile

Benzene

Bromodichloromethane

Bromoform

Bromomethane

Carbon disulfide

Carbon tetrachloride

Chlorobenzene

Chloroethane

Chloroform

Chloromethane

Dibromochloromethane

1, 2 - Dibromo - 3 – chloropropane

1, 2 - Dibromoethane (EDB)

Dibromomethane

Dichlorodifluoromethane

1, 1 – Dichloroethane

1, 2 – Dichloroethane

1, 1 – Dichloroethene

trans - 1, 2 - Dichloroethene

1, 2 - Dichloropropane

cis - 1, 3 - Dichloropropene

trans-1, 3 - Dichloropropene

1, 4 – Dioxane

Ethylbenzene

Ethylene Glycol

2 - Hexanone

Methylene chloride

4 - Methyl - 2 - pentanone (MIBK)

Styrene

1, 1, 1, 2 - Tetrachloroethane

1, 1, 2, 2 - Tetrachloroethane

Tetrachloroethene

Toluene

1, 1, 1 - Trichloroethane

1, 1, 2 - Trichloroethane

Trichloroethene

Trichlorofluoromethane

1, 2, 3 - Trichloropropane

Vinyl acetate

Vinyl chloride

Tert - butyl acetate

tetrahydrofuran

1 - chloro - 4 - trifluoromethylbenz

Semi volatile Compounds

Diphenylamine

Benzidine

bis (2 - Chloroisopropyl) ether

1, 4 – Dioxane

1, 2 – Diphenylhydrazine

Acenaphthene

Acenaphthylene

Acetophenone

2 – Acetylaminofluorene

4 – Aminobiphenyl

Aniline

Benzo (a) anthracene

Benzo (a) pyrene

Benzo (b) fluoranthene

Benzo (ghi) perylene

Benzo (k) fluoranthene

Benzyl alcohol

Diethyl phthalate

Dimethoate

p - Dimethylaminoazobenzene

7, 12 - Dimethylbenz (a) – anthracene

2, 4 – Dimethylphenol

Dimethyl phthalate

Di - n - octyl phthalate

1, 3 – Dinitrobenzene

4, 6 - Dinitro - 2 – methylphenol

2, 4 – Dinitrophenol

2, 4 – Dinitrotoluene

2, 6 – Dinitrotoluene

Dinoseb

Disulfoton

Ethyl methanesulfonate

Fluoranthene

Fluorene

Nitrobenzene

2 - Nitrophenol

4 - Nitrophenol

N - Nitrosodi - n - butylamine

N - Nitrosodiethylamine

N - Nitrosodimethylamine

N - Nitrosodi - n - propylamine

N - Nitrosodiphenylamine

N – Nitrosomethylethylamine

N – Nitrosomorpholine

N – Nitrosopiperidine

N – Nitrosopyrrolidine

5 - Nitro - o – Toluidine

Parathion

Pentachlorobenzene

Pentachloroethane

Pentachloronitrobenzene
8

bis (2 - Chloroethoxy) methane

bis (2 - Chloroethyl) – ether

bis (2 - Ethylhexyl) phthalate

4 - Bromophenyl phenyl ether

Butyl benzyl phthalate

4 – Chloroaniline

4 - Chloro - 3 – methylphenol

2 – Chloronaphthalene

2 – Chlorophenol

4 - Chlorophenyl phenyl ether

Chrysene

Diallate

Dibenz (a, h) anthracene

Dibenzofuran

Di - n butyl phthalate

1, 2 – Dichlorobenzene

1, 3 – Dichlorobenzene

1, 4 – Dichlorobenzene

3, 3' – Dichlorobenzidine

2, 4 – Dichlorophenol

2, 6 – Dichlorophenol

Hexachlorobenzene

Hexachlorobutadiene

Hexachlorocyclopentadiene

Hexachloroethane

Hexachloropropene

Indeno (1, 2, 3 - cd) pyrene

Isodrin

Isophorone

Isosafrole

3 - Methylcholanthrene

Methyl methanesulfonate

2 - Methylnaphthalene

2 – Methylphenol

3 - Methylphenol & 4 – Methylphenol

Naphthalene

1, 4 - Naphthoquinone

1 – Naphthylamine

2 – Naphthylamine

2 – Nitroaniline

3 – Nitroaniline

4 – Nitroaniline

Pentachlorophenol

Phenanthrene

Phenol

Phorate

2 – Picoline

Pronamide

Pyrene

Pyridine

Safrole

1, 2, 4, 5 – Tetrachlorobenzene

2, 3, 4, 6 Tetrachlorophenol

Thionazin

o – Toluidine

1, 2, 4 – Trichlorobenzene

2, 4, 5 – Trichlorophenol

2, 4, 6 – Trichlorophenol

O, O, O – Triethylphosphorothioate

Chlorobenzilate

Aramite

Metals

Aluminum

Antimony

Arsenic

Barium

Beryllium

Boron

Calcium

Cadmium

Cobalt

Chromium

Trivalent Chromium

Copper

Iron

Lead

Lithium

Magnesiium

Manganese

Molybdenum

Nickel

Potassium

Sodium

Selenium

Tin

Strontium

Titanium

Thallium

Zinc

Pesticides

Chlordane (Technical)

alpha – BHC

beta – BHC

delta – BHC

gamma - BHC (Lindane)

Heptachlor

Aldrin

Heptachlor epoxide

Endosulfan I

Dieldrin

4, 4' – DDE

Endrin

Endrin ketone

Endrin aldehyde

Endosulfan II

4, 4' – DDD

Endosulfan sulfate

4, 4' – DDT

Methoxychlor

Toxaphene

Organophosphorus Pesticides

Thionazin Ethyl parathion Tetraethyldithiopyro-phosphate

Polychlorinated Biphenyls (PCBs)

Arochlor 1016

Arochlor 1221

Arochlor 1232

Arochlor 1242

Arochlor 1248

Arochlor 1254

Arochlor 1260
9

Table 2. Summary of Methods

Parameter Analytical Method Preparation Method

pH SW846 9040 SW846 9040

Acidity (Titrimetric) SM20 2310 B (4a)

Alkalinity, Total SM18 2320 B SM18 2320 B

Amenable Cyanide SM18 4500-CN E SM18 4500-CN E

Biochemical Oxygen Demand SM18 5210 B SM18 5210 B

Bromide MCAWW 300.1A MCAWW 300.1A

Chemical Oxygen Demand MCAWW 410.4 MCAWW 410.4

Chloride MCAWW 300.1A MCAWW 300.1A

Cyanide, Total SW846 9012A SW846 9012A

Dissolved Organic Carbon SW846 7196A SW846 7196A

Fluoride MCAWW 300.1A MCAWW 300.1A

Hexavalent Chromium EPA 901.1 MOD

Hardness, Total SM20 2340C

Mercury in Liquid Waste SW846 7470A SW846 7470A

N-Hexane Extractable Material CFR136A 1664A H EPA 1664A

Nitrate as N MCAWW 300.1A MCAWW 300.1A

Nitrite-Nitrate MCAWW 353.2 MCAWW 353.2

Nitrite as N MCAWW 300.1A MCAWW 300.1A

Nitrogen, Ammonia MCAWW 350.1 MCAWW 350.1

Organochlorine Pesticide SW846 8081A SW846 3510C

Organophosphorus Compounds SW846 8141A SW846 3510

Phenolics SW846 9066 SW846 9066

Polychlorinated Biphenyls SW846 8082 SW846 3510C

Semi volatile Organic Compounds SW846 8270C SW846 3520C

Specific Conductance MCAWW 120.1 MCAWW 120.1

Sulfate MCAWW 300.0A MCAWW 300.0A

Sulfides, Total SW846 9030B/903 SW846 9030B/903

Total Phosphorus MCAWW 365.2 MCAWW 365.2

Total Dissolved Solids SM18 2540 C

Total Kjeldahl Nitrogen MCAWW 351.3 MCAWW 351.3

Total Organic Carbon SM20 5310B

Total Suspended Solids SM20 2540D

Trace Inductively Coupled Plasma SW846 6010B SW846 3005A
10

Table 2. Summary of Methods

Parameter Analytical Method Preparation Method

Metals SW846 6010B SW846 3010A

Trivalent Chromium SW846 6010B Wet None

Turbidity (Nephelometric) MCAWW 180.1 MCAWW 180.1

Volatile Organics by GC/MS SW846 8260B SW846 5030B

Ethylene Glycol SW846 8015 SW846 8015

Methylene Blue Activated Substances 

(MBAS)

SM5540C SM5540C

Under the updated sampling plan, the following grab samples were collected at 

each of the volunteered locations: 

A supply water sample (before the blending of additives);

One influent water sample following blending with fracturing additives, excluding 

sand;

Flowback water samples collected on 1, 5 and 14 days after hydraulic fracturing; 

and 

Water from the producing well at 90 days after completion.

Following the collection of the samples and the performance of all of the 

determinations, the data was organized, qualified and tabulated by GTI. 

RESULTS FROM THE MARCELLUS

Throughout the performance of the flowback water sampling program, natural gas 

development companies of the Marcellus Shale provided a high level of access to all of 

the host sites that was necessary to obtain the critical flowback water samples at the 

standardized times of 0, 1, 5, and 14 days following the hydraulic fracturing event of 

each host site well. About a third of the companies assisted with the collection of a 90 

day sampling of the flowback water, as well. In total, 17 shale gas companies enabled 

the sampling of 19 locations within the Marcellus Shale Region, including 3 locations in 

West Virginia and 16 locations in Pennsylvania. 
11

Flowback Water Collection Characteristics 

Water volumes associated with 12 of the 19 wells sampled in this project are shown 

in Table 3. Of the 12 wells reporting water volume information, five wells were vertical 

wells and seven wells were of horizontal configuration. Of the vertical wells, an average 

of approximately 40,000 bbls of influent water were used to achieve fracturing, and 

about 15,000 bbls on average were collected within a 90 day period. Of the horizontal 

wells, an average of approximately 90,000 bbls of influent water were used to achieve 

fracturing, followed by a collection of about 16,000 bbls of effluent water (flowback). 

Cumulative volumes of water collected over time for these 12 completed wells are 

shown in Table 3. 

Table 3: Water Use and Flowback Water Collection Associated with Hydraulic 

Fracturing Completion of Shale Gas Wells

Location Well Type

Total Vol. 

Frac Fluid 

Used, 

bbls

Cumulative Volume of 

Flowback Water, BBL

Percent 

1 Day* 5 Days 14 Days 90 Days Collected

A Vertical 40,046 3,950 10,456 15,023 37.5

B Vertical 94,216 1,095 10,782 13,718 17,890 19.0

C Horizontal 146,226 3,308 9,652 15,991 10.9

D Horizontal 21,144 2,854 8,077 9,938 11,185 52.9

E Horizontal 53,500 8,560 20,330 24,610 25,680 48.0

F Horizontal 77,995 3,272 10,830 12,331 17,413 22.3

G Horizontal 123,921 1,219 7,493 12,471 18,677 15.1

H Vertical 36,035 3,988 16,369 21,282 31,735 88.0

K Horizontal 70,774 5,751 8,016 9,473 13.4

M Horizontal 99,195 16,419 17,935 19,723 19.9

N Vertical 11,435 2,432 2,759 3,043 3,535 30.9

O Horizontal 96,706 5,131 19,202 19.8

Q Vertical 23,593 1,315 3,577 5,090 21.6

S Vertical 16,460 2,094 7,832 9,345 10,723 65.1

Weighted Average % Collected  24.3

* Days from the hydraulic fracturing event. 
12

General Chemistry

A summary of the general chemical characteristics of the water influent streams and 

the flowback water effluents associated with the initiation of the fracing process are 

presented in Table 4. Raw Source water is compared against blended water containing 

conditioning chemicals (minus sand). Dissolved solids measurements for the influent 

waters used for hydraulic fracturing (with additives) had a median value of 735 mg/l, 

which is considered in the range of fresh surface water supplies. Oil and grease 

measurements had a median value of almost 30 mg/l with a range of 0.5 to 255 mg/l. 

Total organic carbon had a range of 5.6 to 1,260 mg/l with a median of 226 mg/l; 

elevated values in these measurements may be due to various degrees of blending of 

reused brine waters into frac job influent water supplies. 

A summary of the same characteristics is tabulated for water supplies from 7 

locations (F, H, I, J, L, M, S) in Table 5; information in this table provides an indication of 

the quality of influent water before the blending of additives. The data in this table 

indicates that water supplies had very low total organic carbon content (< 4 ppm), low 

biochemical oxygen demand (< 2 ppm) and non-detect levels of oils and greases; the 

values for these parameters are well within the ranges expected for normal surface 

waters and groundwater. Total dissolved solids ranged from 50 to 5,500 mg/l with a 

median value around 390 mg/l; the upper end of the range may be due to the varied 

degree of flowback water reuse that is employed at these sites. 

The water is of relatively modest alkalinity with a median values of 85 – 120 mg/l, 

reflecting low carbonate concentrations which allow for very high levels of soluble 

calcium. High levels of calcium confer a very high hardness on the water as evidenced 

by median hardness values of 17,700 and 34,000 mg/l for the 5-day and 14-day sample 

sets, respectively. Cations are dominated by sodium and calcium in this water; anions 

are dominated by chloride. Levels of total organic carbon (TOC) in the flowback water 

samples at 5 and 14 days (with median values of 63 and 39 mg/l) are substantially 

lower (by about 75%) than the TOC of the blended influent water with additives; a 

possible reason for this is that the polyacrylamide friction reducers exert a TOC in the 

influent stream and are removed as water resides in the down-hole environment. The 

same observation is made in comparing biochemical oxygen demand (BOD) values in 
13

flowback water with the BOD of the influent water streams; in general, the BOD levels of 

the 5-day and 14-day flowback waters are less than half the influent BOD 

concentrations. The moderate levels of BOD in the influent waters may have resulted 

from carbonaceous algae growth in the source water or resulted from the biodegradable 

nature of the additives (e.g. polyacrylamide friction reducing compounds). The loss of 

friction reducing compounds due to adherence to surfaces downhole may be 

responsible for the lower BOD concentrations in flowback waters. 

Results from Day 1 and Day 5 are presented in Table 5. Day 1 results, in general, 

show a huge range of values, indicating the rapid change in concentrations with 

initiation of flowback. By Day 5, most sites are demonstrating concentrations trending 

toward the maximum seen by Day 10 or 90. Two interesting observations concern TOC 

and BOD, both of which show a slight decrease from the initial blended water, to Day 1, 

to Day 5. 

Results from Day 14 and Day 90 are presented in Table 6. Day 14 results, in 

general, show a large range of values, based on one sample from Site K that was 

generally less concentrated than the 5 Day sample. Day 90 results are from five sites 

only, and reflect the deviations associated with a relatively small sample size. 

Salt concentrations in influent water and in flowback water generated over time from 

the 19 sampling locations are tabulated in Table 7. As shown in Table 7, influent water 

usually contains moderate to low concentrations of salts. Following the use of this 

water for hydraulic fracturing, a flowback water stream that is collected from the well 

exhibits increasing concentrations of salts with time. 
14

Table 4. Summary of Chemical Characteristics of Water Used for Hydraulic Fracture

Parameter

Raw Source1 Water Blended4Frac Water

Range Median Range Median Units

pH 6.7-7.3 7.1 6.0 - 8.9 7.2 No Units

Acidity < 5 – 5.5 < 5 < 5 - 1230 < 5 mg/l

Total Alkalinity 6.2 – 88.8 71.4 < 1 – 308 81.8 mg/l

Hardness as CaCO3 18 - 1,080 140 26 - 9,500 130.0 mg/l

Total Suspended Solids <2 – 24 9.6 < 2 - 5,290 155.0 mg/l

Turbidity 1.3 – 33.7 4.3 2.7 – 715 249.0 NTU

Chloride 4.1 – 3,000 42.3 18 - 10,700 90.2 mg/l

Total Dissolved Solids251 – 5,510 390 221 - 27,800 735.0 mg/l

Specific Conductance 54.8 – 10,100 466 177 - 34,600 726.0 umhos/cm

Total Kjeldahl Nitrogen < 2.3 – 56.4 2.2 2.3 – 400 33.5 mg/l

Ammonia Nitrogen < 0.24 – 20.8 0.52 0.58 – 441 5.9 mg/l

Nitrate-Nitrite < 0.01 – 3.0 0.51 < 0.032 - 0.34 0.1 mg/l

Nitrite as N < 0.0032 – 4.9 < 0.0032 < 2.0 – 1740 271.0 mg/l

Biochemical Oxygen 

Demand < 2.0 – 110 < 2.0 < 4.3 - 47,400 1730.0 mg/l

Chemical Oxygen Demand < 4.3 – 924 18.4 5.6 - 1,260 226.0 mg/l

Total Organic Carbon (TOC) 1.8 – 202 3.8 5 - 1,270 301.0 mg/l

Dissolved Organic

Carbon 1.4 – 222 3.2 < 0.49 – 255 29.2 mg/l

Oil & Grease (HEM) - < 0.5 < 1.7 – 680 4.6 mg/l

Cyanide, Total < 1.7 – 625 < 1.7 < 0.005 - 0.87 < 0.005 μg/l

Amenable Cyanide < 0.005 - 0.3 < 0.005 < 0.014 – 107 0.9 mg/l

Bromide < 0.0014 – 1.9 0.14 < 0.004 - 58.3 0.004 mg/l

Fluoride < 0.004 - 1.2 < 0.004 < 1.2 - 8.8 < 1.2 mg/l

Total Sulfide 1.2 - 5.6 1.6 < 0.031 – 2920 50.3 mg/l

Sulfate 3.8 – 139 43.7 < 0.03 – 16 0.14 mg/l

Total Phosphorus < 0.03 – 0.1 0.044 < 0.0057 - 0.77 0.033 mg/l

Total Recoverable

Phenolics 0.0057 - 0.14 0.0065 0.05 – 0.50 0.05 mg/l

Methylene Blue Active 

Substances (MBAS)30.05 – 0.50 0.05 6.0 - 8.9 7.2 mg/l

1

 Water Supplies at 7 Locations: F, H, I, J, L, M, S. 2 Upper end concentrations in the TDS range may be due to 

implementation of flowback water reuse and blending into the influent stream. 3 Data analysis for 8 Locations: D, F, 

H, I, J, M, N, S. 4 Additives included corrosion inhibitors, scale inhibitors, friction reducers, biocides, and oxygen 

scavengers. Blended water samples were taken before the addition of sand. 
15

Table 5: Range of Results from 1 and 5 Day Samples

General Chemistry Day 1 Day 5

Range Median Range Median Units

pH 5.9- 7.9 7.4 5.8- 7.2 6.6 No Units

Acidity ND 5- 447 48.7 mg/l

Total Alkalinity 107- 577 251 48.8- 327 135 mg/l

Hardness as CaCO3 156- 25,000 4,150 5,100- 55,000 20,000 mg/l

Total Suspended Solids 6.8- 522 71 10.8- 3220 102 mg/l

Turbidity 10- 461 52.1 14- 1540 92 NTU

Chloride 64.2- 151,000 9,890 26,400- 148,000 43,900 mg/l

Total Dissolved Solids 680- 122,000 18,900 38,500- 238,000 72,700 mg/l

Specific Conductance 479 645,000 37,750 79,500- 470,000 175,000 umhos/cm

Total Kjeldahl Nitrogen 14.2- 158 52.9 38- 204 89.5 mg/l

Ammonia Nitrogen 2.8- 173 32 29.4- 242 90 mg/l

Nitrate-Nitrite 0.01- 2.8 0.5 0.049- 1.2 0.36 mg/l

Nitrite as N ND- 6.7 3.1 4.8- 25.9 11.8 mg/l

Biochemical Oxygen

Demand

27.6- 1,440 327.5 37.1- 1,950 141 mg/l

Chemical Oxygen 

Demand

397- 10,700 1,660 195- 17,700 4,845 mg/l

Total Organic Carbon 2.2- 672 142 3.7- 388 61.8 mg/l

Dissolved Organic

Carbon

20.2- 657 253 30.7- 501 88.3 mg/l

Oil & Grease (HEM) 5.7- 53.9 13.7 0- 655 16.2 mg/l

Cyanide, Total 6.6- 177 21.5 5.2- 72.1 13.6 ug/L

Bromide 35.5- 376 120 0- 1190 445 mg/l

Fluoride 0.077- 32.9 0.975 0.045- 17.3 2.4 mg/l

Total Sulfide 1.6- 3.2 1.6 1.6- 5.6 2.4 mg/l

Sulfate 10.7- 348 46 2.4- 106 37.8 mg/l

Total Phosphorus 0.037- 21.8 0.18 0.053- 2.3 0.305 mg/l

Total Recoverable

Phenolics

0.007- 0.064 0.027 0.0076- 0.31 0.024 mg/l
16

Table 6: Range of Results from 14 and 90 Day Samples

Day 14 (17 Sites Reporting) Day 90 (5 Sites Reporting)

General Chemistry Range Median Range Median Units

pH 4.9- 6.8 6.2 5.2- 6.2 5.9 No Units

Acidity 19.4- 473 114 162- 925 220 mg/l

Total Alkalinity 26.1- 121 85.2 7.5- 75.2 41.4 mg/l

Hardness as CaCO3 630- 95,000 34,000 40,000- 85,000 77,000 mg/l

Total Suspended Solids 17- 1150 209 150- 446 201 mg/l

Turbidity 10.5- 1090 233 106- 277 174 NTU

Chloride 1,670- 181,000 78,100 78,300- 185,000 122,000 mg/l

Total Dissolved Solids 3,010- 261,000 120,000 155,000- 345,000 216,000 mg/l

Specific Conductance 6,800- 570,000 256,000 249,000- 600,000 385,000 umhos/cm

Total Kjeldahl Nitrogen 5.6- 261 116 92.8- 312 136 mg/l

Ammonia Nitrogen 3.7- 359 121 96- 416 259 mg/l

Nitrate-Nitrite 0.025- 0.92 0.25 ND- 0.029 0.0145 mg/l

Nitrite as N 1.7- 77.4 18.75 42.8- 42.8 42.8 mg/l

Biochemical Oxygen

Demand

2.8- 2070 39.8 4.1- 1080 33.6 mg/l

Chemical Oxygen 

Demand

228- 21,900 8530 2,630- 36,600 16,200 mg/l

Total Organic Carbon 1.2- 509 38.7 4- 5,680 117 mg/l

Dissolved Organic

Carbon

5- 695 43 3.3- 5,960 117 mg/l

Oil & Grease (HEM) 7.4- 103 30.8 14.7- 62.6 21.3 0

Cyanide, Total 1.9- 7.4 5 42.6- 42.6 42.6 ug/L

Bromide 15.8- 1,600 704 766- 1,990 1,260 mg/l

Fluoride ND 2 ND- mg/l

Total Sulfide 1.6- 3.2 2 2.4- 4 3.2 mg/l

Sulfate 0.078- 89.3 40 83.8- 83.8 83.8 mg/l

Total Phosphorus 0.035- 2.2 0.115 ND mg/l

Total Recoverable

Phenolics

0.006- 0.31 0.016 0.0091- 0.23 0.0295 mg/l
17

Table 7: Concentration of Total Dissolved Solids in Flowback Water at 19 Locations,

(mg/l)

Location Day 0* Day 1 Day 5 Day 14 Day 90

A 990 15,400 54,800 105,000 216,000

B 27,800 22,400 87,800 112,000 194,000

C 719 24,700 61,900 110,000 267,000

D 1,410 9,020 40,700 155,000

E 5,910 28,900 55,100 124,000

F 462 61,200 116,000 157,000

G 1,920 74,600 125,000 169,000

H 7,080 19,200 150,000 206,000 345,000

I 265 122,000 238,000 261,000

J 4,840 5,090 48,700 19,100

K 804 18,600 39,400 3,010

L 221 20,400 72,700 109,000

M 371 228,000

N 735 31,800 116,000

O 2,670 17,400 125,000 186,000

P 401 11,600 78,600 63,900

Q 311 16,600 38,500 120,000

R 481 15,100 46,900 20,900

S 280 680 58,300 124,000

*Day 0 sample was taken of the influent water plus additives without sand.

A typical profile of salt concentrations (such as Location B) measured in flowback 

water with time is shown in Figure 1. Early flowback water emerging soon after the frac 

job is relatively low in TDS content. Following the initial day, the concentration of total 

dissolved solids increases with time from low salt concentrations to a plateau of 

elevated salt levels as measured at 14 and 90 days. Also shown in this diagram is the 

marked concomitant decrease in flowback brine flow with time, exhibiting a high initial 

flow rate of over 2,400 bbls/day, then decreasing to a minimal flow rate of less than 55 

bbls/day after the initial few weeks following completion, a 98% reduction of daily flow. 

The lowest flow rate bar shown on the chart in Figure 1 was calculated from 
18

cumulative water data between 14 and 90 days; actual flows in the 60 to 90 day period 

are significantly less than 55 bbls/day. The diagram, however, demonstrates that 

although the TDS levels in the flowback water emerging between 14 and 90 days 

almost doubles to nearly reach 200,000 mg/l. The daily brine volumes produced by the 

well decrease to a low rate that can be easily managed as a typical produced water 

stream. 

Figure 1. Salt Concentration and Flowback Water Flow Versus Time from Location B 

General characteristics of the samples tested in this project appear very consistent with 

the ranges of values reported in the literature for normal produced waters (USGS, 

2004). The large database collected by the USGS indicates that salinities for produced 

waters generated among all basins can vary widely from approximately 5,000 to greater 

than 350,000 mg/l of total dissolved solids. Chloride is the dominant anion in nearly all 

formation waters associated with petroleum and with most conventional natural gas 
19

(Kharaka and Rice, 2004). Sodium is the most dominant cation in most producing fields 

and constitutes 70 to more than 90% of total cations (USGS, 2004). General 

characterization data from the waters tested at the 19 locations of this project appear 

consistent with much of the available compositional information available from the 

USGS database. The USGS database containing produced water characterization data 

from more than 60,000 wells is accessible from the Internet at: 

http://energy.cr.usgs.gov/prov/prodwat/intro.htm . 

Total organic carbon reflects a trend generally opposite that of the total dissolved 

solids. Table 8 shows that the TOC in the flowback water typically decreases over time. 

The BOD (Table 9) is more erratic. Some wells remain constant over time, while other 

wells increase; still others decrease in measured BOD with time. 

Table 8: Total Organic Carbon TOC (mg/l)

Site Day 0 Day 1 Day 5 Day 14

A 350 260 NS 38.7

B 168 207 50.6 34.2

C 167 82.5 32.9 14.4

D 741 342 161 NS

E 226 108 46.2 5.9

F 205 43.5 62.8 44

G 123 60.8 42.2 NS

H 78.3 1260 443 119

I 607 610 48 12.8

J 569 56.6 27.5 23.6

K 949 124 103 7.2

L 202 155 115 80.5

M 86.6 2.2 3.7 1.2

N 208 28.1 37.8 NS

O 575 308 237 509

P 5.6 292 287 226

Q 410 142 46.5 24

R 173 604 388 323

S 931 672 104 150

Median 208 155 57 36

Average 357 282 124 101
20

Table 9: Biochemical Oxygen Demand (BOD mg/l)

Site Day 0 Day 1 Day 5 Day 14

A 794 353 3

B ND 132 1,950 149

C 5 132 63.7 39.8

D 438 656 721 NS

E 788 158 106 32.4

F 154 75.4 64.8 120

G 302 144 7.3 NS

H 110 1,740 737 138

I 578 399 99 10.4

J 47 43 48 20.3

K 430 650 214 30.5

L ND ND 27.6 37

M 137 36.3 103 10

N 166 73.2 70.9 NS

O 924 606 1,520 725

P 4 391 1,260 752

Q 121 184 144 98.1

R 271 692 1250 6

S 2,220 1,440 218 990

Median 271 269 106 38

Average 441 439 453 198

Organic Compounds

The organic compounds included in the characterization of water samples included 

the categories of volatile organics, semi volatile organics, chlorinated pesticides, 

organophosphorus pesticides, and polychlorinated biphenyls. Most of the compounds 

in the first two categories and all compounds in the last three categories were included 

on the list of analyses in response to recommendations from PA-DEP and WV-DEP. 

The following sections summarize the results among all five of the categories of 

analysis. 
21

Volatile Compounds

Samples collected from Locations A through S were analyzed for 70 volatile 

compounds of highly varied chemical characteristics, including the volatile hydrocarbon 

constituents that are normally found in produced water (such as benzene, toluene, 

ethylbenzene, and xylenes – or BTEX, and naphthalene) as well as constituents not 

known to be associated with conventional produced water such as chlorinated solvents 

and halogenated aromatics. 

Source water data (Day 0 minus sand) are presented in Table 10. Of 1330 

measurements, only 92 observations of volatile compounds were made. Acetone was 

measured in 12 samples, representing the use of acetone as a component of the 

additives. BTEX and alkylated benzene isomers likely represent a component of water 

reuse from previous sites. Traces of halogenated solvents occasionally occur at the 

part per billion level. Apparently, the additives used in the fracking process do not 

manifest themselves amongst the most problematic volatile components. 

As noted before, the organic components, unlike total salts, do not follow a timed 

based profile. In general, their appearance in the flowback waters appears anywhere 

from low and constant or intermittent and random. As such, the best means of 

presenting the volatile data for the 19 sites is to present tablulated distributions, ie., the 

number of observations within a stated concentration range. Table 11 shows the 

distribution of observations for all 60 samples. As an example, p-Isopropyltoluene was 

observed once at a concentration between 50-99 μg/l, twice between 10-49 μg/l, once 

between 1-4.9 μg/l, and undetected (ND) in 56 samples. Many of the compounds were 

observed only once in sixty samples, making them either incidental or mistaken. No 

compound was encountered in all sixty samples. The chemical most likely to be 

observed was acetone in 48 of sixty samples. Thirty five of the compounds from the 

voilatiles list were never observed. In total, 4200 measurements were taken and 3710 

of them were “non-detects.”
22

Table 10: Influent Water Day 0 (minus sand)

Volatiles Observations Range, μg/l Median, μg/l

Naphthalene 7 0.55- 820 3.8

n – Propylbenzene 1 ND- 2

1, 2, 4 – Trimethylbenzene 10 0.72- 140 9.15

1, 3, 5 – Trimethylbenzene 7 2.8- 100 7.7

Isopropylbenzene 2 0.95- 0.95 0.95

2 – Butanone 2 3.6- 7.5 5.55

Xylenes (total) 11 2.6- 210 18

sec – Butylbenzene 2 3.2- 84 43.6

Acetone 12 5.4- 170 17.5

Benzene 4 2.2- 6.7 6.7

Bromodichloromethane 1 ND- 2

Bromoform 4 7.8- 9.3 8.55

Carbon disulfide 4 1.6- 54,000 12,250

Chloroform 1 ND- 2.4

Dibromochloromethane 1 ND- 2.1

1, 2 – Dichloroethane 1 ND 2.6

Ethylbenzene 5 0.81- 19 1.7

Methylene chloride 1 ND- 13

Tetrachloroethene 2 1.3- 1.4

Toluene 13 0.93- 81 5.6

Trichloroethene 1 ND- 0.81

Total Observations 92 of 1330 Measurements

Constituents that exceeded 100 ppb included components that are commonly 

present in conventional produced water, such as naphthalene, BTEX, several 

methylated benzene compounds and an alkylated toluene (p-isopropyltoluene). Few 

determinations of these compounds exceeded 1 ppm and only one occurrence was 

above 2 ppm. In the locations where BTEX was measured at levels above 100 ppb, 

BTEX levels in the 5-day and 14-day flowback waters that were in contact with the 

natural gas producing formation were generally higher than BTEX concentrations in the 

influent water streams, indicating that these compounds are naturally occurring and not 

the result of additives. Levels of BTEX and methylated aromatics vary from location to 

location. Determination of factors that control levels of these compounds could 
23

potentially be determined through a correlation of the composition of volatiles and other 

flowback water characteristics with the key shale gas development parameters of 

geographic area, depth of wells, completion methods, etc. For a distribution of all 

volatile organic concentration observations, see Figure 2.

Table 11: Number of Observations of 70 Volatile Compounds in All 60 Marcellus Samples 

Number of Observations

>1000

500-

999

100-

499

50-

99

10-

49

5-

9.9

1-

4.9

NDBetween Limits in μg/l 1 ND 

p – Isopropyltoluene 0 0 0 1 2 0 1 0 56

Naphthalene 0 2 1 0 2 0 8 3 44

n – Propylbenzene 0 0 0 1 0 0 1 0 58

1, 2, 3 – Trichlorobenzene 0 0 0 0 1 1 0 0 58

1, 2, 4 – Trichlorobenzene 0 0 0 0 0 0 1 0 59

1, 2, 4 – Trimethylbenzene 0 4 1 5 8 2 14 5 21

1, 3, 5 – Trimethylbenzene 0 3 2 1 7 6 7 2 32

Isopropylbenzene 0 0 2 1 0 0 2 2 53

2 – Butanone 0 0 0 0 2 2 1 0 55

Xylenes (total) 4 1 8 0 8 7 7 0 25

n - Butylbenzene 0 0 0 0 0 0 1 0 59

sec - Butylbenzene 0 0 0 2 0 0 0 0 58

Acetone 4 1 9 2 26 5 0 0 12

Acrylonitrile 0 0 0 0 0 1 0 0 59

Benzene 3 1 7 1 2 7 7 1 31

Bromoform 0 0 0 0 0 1 0 0 59

Bromomethane 0 0 1 0 0 0 0 0 59

Carbon disulfide 2 0 2 0 1 0 0 0 55

Chloroform 0 0 0 0 1 0 1 0 58

Chloromethane 0 0 1 0 0 1 1 0 57

Ethylbenzene 0 1 4 1 6 1 5 3 39

Methylene chloride 0 0 0 0 0 1 2 0 57

4 - Methyl - 2 - pentanone (MIBK) 0 0 0 0 0 0 0 1 59

Styrene 0 0 0 0 0 0 1 0 59

Tetrachloroethene 0 0 0 0 0 1 0 0 59

Toluene 5 4 4 2 3 2 19 2 19

All 35 Others (See Table 1) 0 0 0 0 0 0 0 0 2450

Total 18 17 42 17 69 38 79 19 3710
24

Semi volatile Compounds

A total of 112 semi volatile organic compounds (as listed in Table 1) were included 

in the analysis of influent water and in flowback water samples. A summary of the 

results of semi volatile determinations in these samples the day 0 source water 

(chemical additives minus sand) is presented in Table 12. The most commonly 

encountered semi volatiles belong to the phthalate ester group, probably representing 

introduced plasticizers. Pyridine is commonly encountered and possibly represents a 

residue from some of the manufacture of some of the additives. Occasional traces of 

PAH’s are present, likely from water reuse in some of the input waters. In a total of 19 

samples, a total of 2204 chemical tests were performed. Only 76 samples were above 

appears to not appreciably influence the concentrations of the 116 listed semi volatile

organics.

Observations in 60 Samples from the Marcellus 4200

3710

472

18

0

500

1000

1500

2000

2500

3000

3500

4000

4500

All Samples ND <1PPM > 1PPM Number of Observations

Figure 2: Distribution of Observations for 70 Volatile Organics from 60 Samples from 

the Marcellus
25

For all sample times, semi-volatile compound determinations that were detectable 

are listed in Table 13. As seen in this table, only four constituents were measured in 

any of the samples at levels exceeding 10 ppb. Acetophenone and aniline are 

commonly associated with fossil fuels, as are the methylated phenols. The only 

compound that was measured above 1 ppm was pyridine. Pyridine is a nucleophile 

Table 12: Semi-Volatile Content in 19 Marcellus Influent Samples 

Source Water Day 0

Observations

In 19 Samples Range, μg/l

Median of

Observation

Acetophenone 1 ND- 0.97

Benzo (a) anthracene 1 ND- 1.1

Benzo (a) pyrene 1 ND- 6.9

Benzo (b) fluoranthene 1 ND- 11

Benzo (ghi) perylene 1 ND- 7.4

Benzo (k) fluoranthene 1 ND- 6.7 6.7

Benzyl alcohol 2 74- 74 74

bis (2 - Chloroethyl) - ether 1 ND- 4300

bis (2 - Ethylhexyl) phthalate 11 2- 21 9.4

Butyl benzyl phthalate 1 ND- 5.1

Chrysene 1 1.7- 1.7 1.7

Dibenz (a, h) anthracene 1 ND- 12 12

Di - n butyl phthalate 9 0.29- 1.7 0.6

1, 2 - Dichlorobenzene 1 ND- 0.68

1, 4 - Dichlorobenzene 1 ND- 0.6

2, 6 - Dichlorophenol 1 ND- 2

Diethyl phthalate 2 0.49- 1.8 1.145

2, 4 - Dimethylphenol 1 ND- 0.39

Fluoranthene 1 ND- 5.5

Fluorene 2 0.83- 1.2 1.015

Indeno (1, 2, 3 - cd) pyrene 2 10- 10 10

2 - Methylnaphthalene 7 1.3- 300 7.5

Naphthalene 6 0.61- 1800 4.3

Phenanthrene 7 0.28- 24 1.3

2 - Picoline 1 ND- 5.3

Pyrene 3 0.19- 0.54 0.22

Pyridine 9 0.91- 510 17

All 89 Other Chemicals (Table 1) 0 ND ND
26

used widely in the manufacture of certain chemicals and pharmaceuticals. Its presence 

may be due to its use as a precursor in the manufacture of one of the hydraulic 

fracturing additives. Most the semi volatile determinations were either non-detect (> 

96% of the measurements) or at low trace levels (Figure 3). Most of the chemicals in 

Table 13 appeared as chance encounters, ie., detection in one or two of sixty samples.

Distribution of Semi-Volatile Concentrations in

 60 Marcellus Flowback Samples

6960

6593

363

4

0

1000

2000

3000

4000

5000

6000

7000

8000

All Tests ND <1 ppm >1ppm Number of Observations

Figure 3: Distribution of Observations of Semi-Volatiles in 60 Marcellus Flowback Samples from 19 

Sites
27

Table 13: Number of Observations of 116 Semi- Volatile Compounds in all 60 Marcellus 

Samples 

Number of Observations

>1000

500-

999

100-

499

50-

99

10-

49

5-

9.9

1-

4.9

NDBetween Limits in μg/l 0.99 ND 

Diphenylamine 0 0 0 0 0 0 2 0 58

1, 4 – Dioxane 1 0 0 0 15 9 4 2 29

Acenaphthene 0 0 0 0 0 0 0 3 57

Acenaphthylene 0 0 0 0 0 0 0 1 59

Acetophenone 0 0 0 0 6 3 6 9 36

Aniline 0 0 0 0 0 0 2 0 58

Benzo (a) anthracene 0 0 0 0 0 0 2 0 58

Benzo (a) pyrene 0 0 0 0 0 0 2 0 58

Benzo (b) fluoranthene 0 0 0 0 0 0 2 0 58

Benzo (ghi) perylene 0 0 0 0 0 0 3 0 57

Benzo (k) fluoranthene 0 0 0 0 0 0 1 1 58

Benzyl alcohol 0 0 1 0 2 3 1 0 53

bis (2 - Chloroethyl) - ether 0 0 0 0 1 0 0 0 59

bis (2 - Ethylhexyl) phthalate 0 2 0 0 8 9 15 1 25

Butyl benzyl phthalate 0 0 0 0 1 3 0 0 56

Chrysene 0 0 0 0 0 0 2 0 58

Dibenz (a, h) anthracene 0 0 0 0 0 0 2 0 58

Di - n butyl phthalate 0 0 1 1 3 2 5 10 38

1, 2 - Dichlorobenzene 0 0 0 0 0 0 0 2 58

1, 3 - Dichlorobenzene 0 0 0 0 0 0 0 1 59

1, 4 - Dichlorobenzene 0 0 0 0 0 0 0 2 58

Diethyl phthalate 0 0 0 0 1 0 8 4 47

2, 4 - Dimethylphenol 0 0 0 0 3 4 1 2 50

Dimethyl phthalate 0 0 0 0 0 1 0 0 59

Di - n - octyl phthalate 0 0 0 0 2 3 3 0 52

Disulfoton 0 0 0 0 0 0 1 0 59

Ethyl methanesulfonate 0 0 0 0 0 0 0 0 60

Fluoranthene 0 0 0 0 0 5 2 0 53

Fluorene 0 0 0 0 0 2 2 8 48

Hexachlorobenzene 0 0 0 0 0 0 1 1 58

Indeno (1, 2, 3 - cd) pyrene 0 0 0 0 0 0 2 0 58

2 - Methylnaphthalene 0 0 3 2 0 0 9 6 40

2 – Methylphenol 0 0 0 0 3 6 2 3 46

3 - Methylphenol & 4 - Methylphenol 0 0 0 0 7 3 3 13 34

Naphthalene 1 1 0 0 3 1 5 5 44

4 – Nitroaniline 0 0 0 0 0 0 1 0 59

N - Nitrosodiphenylamine 0 0 0 0 0 0 1 0 59

Phenanthrene 0 0 0 0 2 0 5 7 46

Phenol 0 0 0 0 5 0 4 2 49

2 – Picoline 0 0 0 0 1 0 1 0 58

Pyrene 0 0 0 0 1 0 3 5 51

Pyridine 2 2 21 4 5 3 6 0 17

1, 2, 4 - Trichlorobenzene 0 0 0 0 0 0 0 2 58

All 74 Others (See Table 1) 0 0 0 0 0 0 0 0 4440

Total 4 5 26 7 69 57 109 90 6593
28

Pesticides

Determinations of the 20 chlorinated pesticides and three organophosphorus 

pesticides listed in Table 1 were conducted on the influent and 14-day flowback water 

streams. None of these pesticides were detected. This would suggest that no 

chlorinated pesticides were introduced with the additives with the influent water during 

well completions. 

Polychlorinated Biphenyls (PCBs)

Determinations of the 7 polychlorinated biphenyl compounds (arochlors) listed in 

Table 1 were conducted on the influent and 14-day flowback water streams. Results 

from the measurements of organophosphorus pesticides in all samples of the influent 

water and in the 14-day flowback water are summarized in Figures 16 and 17, 

respectively. As seen from these graphs, all determinations for PCBs were measured 

as non-detect. This would suggest that no PCBs were introduced with the additives 

with the influent water during well completions. 

Metals

Total metals data for the six raw water samples and the 19 influent water samples 

with additives are presented in Table 14. For the most part, the differences in the 

ranges of concentration between the two sample sets can be explained by the 

differences expected for the different population (6 vs 19 samples). There is an added 

unknown statistical bias in the subset of the number of samples in the influent utilizing 

blended (reused) water versus the number of raw water sources utilizing reused water. 
29

Table 14: Metals Data in Raw Water and Source Water with Additives

All units mg/l

Raw Water day 0

6 Samples

Influent with Additives

19 Samples

Obs Range Median Obs Range Median

Aluminum 4 0.122- 0.264 0.213 5 0.177- 2 0.4

Antimony 2 0.0146- 0.0154 0.015 1 0.015- 0.0154 0.0154

Arsenic 0 0

Barium 6 0.243- 5.48 0.589 6 0.108- 87.1 1.005

Beryllium 0 0

Boron 5 0.0189- 2.45 0.0343 5 0.019- 2.58 0.0433

Calcium 6 4.88- 40.1 31.75 6 6.69- 241 32.2

Cadmium 1 0.0017- 0.0017 0.0017 1 0.002- 0.0017 0.0017

Cobalt 0 ND 0 ND

Chromium 0 ND 0 ND

Trivalent 

Chromium 0

ND

0

ND

Copper 0 ND 1 0.045- 0.0445 0.0445

Iron 6 0.192- 4.31 0.4995 6 0.137- 3.56 0.4455

Lead 0 ND 0 ND

Lithium 3 0.0338- 2.24 0.0422 3 0.03- 2.34 2.05

Magnesiium 6 1.08- 183 5.845 6 1.25- 183 13.87

Manganese 6 0.0087- 0.237 0.0817 5 0.008- 0.395 0.127

Molybdenum 0 ND 0 ND

Nickel 1 ND- 0.0111 0.0111 1 0.02- 0.0195 0.0195

Potassium 4 2.36- 53.6 2.89 4 2.25- 57.4 7.265

Sodium 6 4.2- 1380 31.05 6 32.6- 1460 59.5

Selenium 0 ND- 1 0.035- 0.0353 0.0353

Tin 0 ND- 0 ND

Strontium 6 0.352- 76.2 0.6785 6 0.206- 78.5 0.919

Titanium 1 ND- 0.0299 0.0299 2 0.019- 0.0271 0.0233

Thallium 0 ND 0 ND

Zinc 6 0.0257- 0.172 0.0486 6 0.035- 0.176 0.0635

Mercury 3 5E-05- 0.00061 5E-05 3 4E-05- 6E-05 5E-05

Metals data, especially the top five cations, sodum, barium, iron, strontium and 

magnesium, tend to follow a timed profile. These data are presented by collection day 

to better show the trends. Summary data for days 1 and 5 are presented in Table 15. 

Summary data for days 14 and 90 are presented in Table 16. The 90 day data present 

a much smaller database (5 sites compared to 17-19 samples in the other sets). The 

top six metal ions in flowback water are sodium, calcium, magnesium, strontium and 

iron and potassium. These ions, and most others listed, increase from day 1 to day 90 

and represent a significant increase over the raw water and influent water data in the 

Table 14.
30

Table 15: Metals Data for Marcellus Flowback Days 1 and 5

Day 1 (19 Samples) Day 5 (18 Samples)

Metals (mg/l) Obs Range Median Obs Range Median

Aluminum 17 0.165- 4.03 0.507 17 0.111- 47.2 0.378

Antimony 13 0.0089- 0.0378 0.0247 10 0.017- 0.0472 0.0325

Arsenic 12 0.0133- 0.0551 0.0333 11 0.014- 0.124 0.043

Barium 19 0.332- 1450 37.6 18 21.4- 13900 736.5

Beryllium 0 0

Boron 19 0.0181- 13.1 6.68 18 3.14- 97.9 12.05

Calcium 19 35.2- 19700 833 18 1440- 23500 5555

Cadmium 4 0.0002- 0.0029 0.00235 7 0.002- 0.0096 0.0038

Cobalt 3 0.0045- 0.0105 0.0057 0

Chromium 16 0.0075- 0.359 0.0318 14 0.008- 0.152 0.0271

Trivalent 

Chromium 6 0.0075- 0.0491 0.0293 9 0.0075- 0.0924 0.0272

Copper 11 0.0096- 0.255 0.0571 9 0.029- 4.15 0.0789

Iron 19 2.68- 67.2 13.9 18 20.4- 180 41.25

Lead 12 0.0017- 0.0709 0.02565 8 0.021- 0.606 0.05605

Lithium 18 4.06- 129 14.05 18 10.6- 153 42.75

Magnesiium 19 16- 1320 89 18 135- 1550 581.5

Manganese 19 0.146- 5.96 0.782 18 0.881- 7.04 2.64

Molybdenum 19 0.0089- 0.372 0.0356 15 0.009- 0.147 0.0317

Nickel 17 0.0106- 0.203 0.0286 6 0.011- 0.187 0.02275

Potassium 19 2.69- 923 109 18 48.9- 2430 300.5

Sodium 19 63.8- 34700 6290 18 10700- 65100 18100

Selenium 1 ND- 0.0043 0.0043 0

Tin 3 0.0038- 0.007 0.0051 1 ND- 0.026 0.0257

Strontium 19 0.58- 4330 167 18 345- 4830 1160

Titanium 11 0.0151- 0.092 0.0385 9 0.024- 0.313 0.107

Thallium 3 0.0049- 0.0272 0.0054 3 0.019- 0.0246 0.0194

Zinc 18 0.0561- 0.665 0.191 18 0.068- 1.23 0.164

Mercury 6 4E-05- 0.000074 5.05E-05 5 2E-05- 0.00024 0.000043
31

Table 16: Metals Data for Marcellus Flowback Days 14 and 90

Day 14 with 17 Sites Reporting Day 90 with 5 Sites Reporting

Metals (mg/l) Obs Range Median Obs Range Median

Aluminum 15 0.158- 4.68 0.835 5 0.173- 1.04 0.37

Antimony 8 0.0092- 0.0491 0.02645 0

Arsenic 12 0.0126- 0.135 0.07695 4 0.0462- 0.114 0.0726

Barium 17 0.0631- 12500 589 5 133- 4220 1440

Beryllium 2 0.00021- 0.0022 0.001205 0

Boron 17 0.464- 114 13.6 5 13- 145 25.3

Calcium 17 14.3- 140000 9600 5 8500- 24000 18300

Cadmium 12 0.0014- 0.0124 0.00385 4 0.0025- 0.0077 0.00255

Cobalt 2 0.0109- 0.0278 0.01935 0

Chromium 15 0.0012- 0.567 0.0312 3 0.0135- 0.0209 0.0177

Trivalent 

Chromium 10 0.0012- 0.0942 0.01335 1 ND- 0.0175 0.0175

Copper 11 0.0077- 0.518 0.079 2 0.0272- 0.0515 0.03935

Iron 17 0.439- 574 73.2 5 69.7- 158 93

Lead 10 0.0033- 0.596 0.092 3 0.0456- 0.97 0.068

Lithium 17 0.0077- 201 73.7 5 44.5- 137 88.6

Magnesiium 17 2.83- 1800 794 5 933- 1790 1710

Manganese 17 0.0587- 18.6 4.79 5 2.13- 9.77 4.72

Molybdenum 11 0.0066- 0.188 0.0324 1 0.017- 0.017 0.017

Nickel 8 0.0013- 0.769 0.05795 0

Potassium 17 8.23- 2820 368 5 191- 3950 548

Sodium 17 70.7- 85600 31500 5 26900- 75800 39700

Selenium 4 0.0301- 0.0956 0.0367 1 ND- 0.044

Tin 4 0.0039- 0.0235 0.02185 0

Strontium 17 0.103- 5570 1850 5 1220- 8020 3480

Titanium 10 0.0636- 0.247 0.1435 4 0.13- 0.242 0.173

Thallium 2 0.0339- 0.151 0.09245 1 0.168- 0.168 0.168

Zinc 16 0.0117- 2.29 0.226 5 0.0293- 0.811 0.178

Mercury 2 0.000049- 0.00029 0.00017 1 ND- 0.000068
32

RESULTS FROM THE BARNETT

Using the same protocols employed in the Marcellus, five sites were sampled in the 

Barnett. Flowback water samples were collected at the time intervals indicated in Table 

17. Initial raw water for Sites LPG1 and LPG2 was from the same source and is 

represented by a single sample. Initial raw water for Sites LPG 3, LPG 4, and LPG5

was from the same source and is represented as a single sample. Four of five sites 

reported data on Day 1. Three sites reported on Day 5 and one site reported on Day 6. 

These four samples dates are treated together in discussions of Day 5-6 events. Three 

sites reported on Day 10 and one site reported on Day 12. These sample dates are 

treated together in discussions of Day 10-12 events. Sampling and assurance plans 

followed those developed for the Marcellus in Appendices A and B. Chemical results 

were collected and treated as described in Tables 1 and 2. Results from all samples 

taken from Sites LPG 1-5 are presented with the analysis results from the Marcellus in 

the GTI Flowback Water Information Base in Excel Format that was submitted by GTI to 

RPSEA. 

 Flowback Water Collection Volumes

Flowback volumes for Sites LPG1-4 were recorded on a daily basis. Selected 

points are presented in Table 18 to correspond with the chemical data presented the 

following sections. Data are similar in form to those presented for the Marcellus in 

Table 3. Like the Marcellus, water recovery is rapid during the first few days, with 

recovery rates slowing by day 10-12 after fracture.

Table 17: Sample Dates (Days after Fracture) for 5 Sites in the Barnett

Day 0 Day1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG1 X X X X

LPG2 X X X X

LPG3 X X X X

LPG4 X X X

LPG 5 X
33

General Chemistry

A summary of the general chemical characteristics of the two water influent samples 

and the flowback water effluents associated with the completion and operation of wells 

of the 5 sampling locations are presented in Tables 19-22. Characteristics of the two 

samples of raw influent water are shown in Table 19. The pH of these streams ranging 

from 7.7 to 8.5 seems to be normal for surface waters. Dissolved solids measurements 

for the influent waters used for hydraulic fracturing (with additives) had a range of 200-

800 mg/l, which is considered in the range of fresh surface water supplies. 

Interestingly, oil and grease measurements had a range of 17-22 mg/l and total organic 

carbon had a range of 124-143 mg/l; elevated values in these measurements may be 

due to various degrees of blending of reused waters into frac job influent water supplies. 

Table 18: Cumulative Flow (BBL) for 5 Sites in the Barnett

Initial Fracture (BBL) Recovered Volumes (Cumulative) BBL

Day1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG1 129,336 2,402 7,566 11,806 12,752 14,154 20,346 23,082

LPG2 127,076 957 3,256 5,175 6,171 7,146 10,031 11,878

LPG3 100,611 4,117 8,071 13,735 14,827 15,972 19,021 20,960

LPG4 155,362 873 2,878 3,986 4,274 4,522 5,209 5,745

LPG5 X X X X X X X X
34

Table 19. Summary of Chemical Characteristics of Influent Water Used for 

Hydraulic Fracturing after Additives were Blended

General Chemistry LPG 3,4,5 LPG 1,2 Average Units

pH 7.7 8.5 No Units

Acidity ND ND ND mg/L

Total Alkalinity 251 236 243.5 mg/L

Hardness as CaCO3 28 100 64 mg/L

Total Suspended Solids 360 80 220 mg/L

Turbidity 265 116 190.5 NTU

Chloride 151 21.6 86.3 mg/L

Total Dissolved Solids 800 203 501.5 mg/L

Specific Conductance 1550 484 1017 umhos/cm

Total Kjeldahl Nitrogen 36 21.9 28.95 mg/L

Ammonia Nitrogen 3.9 8 5.95 mg/L

Nitrate-Nitrite 0.048 0.036 0.042 mg/L

Nitrite as N 0.57 0.14 0.355 mg/L

Biochemical Oxygen Demand 130 245 187.5 mg/L

Chemical Oxygen Demand 829 559 694 mg/L

Total Organic Carbon (TOC) 143 124 133.5 mg/L

Dissolved Organic Carbon 84.3 281 182.65 mg/L

Oil & Grease (HEM) 22.2 17 19.6 mg/L

Cyanide, Total ND 1.9 1.9 mg/L

Amenable Cyanide ND ND ND mg/L

Bromide 0.7 ND 0.7 mg/L

Fluoride 1.00 0.096 0.548 mg/L

Total Sulfide ND ND ND mg/L

Sulfate 107 28 67.5 mg/L

Total Phosphorus 3 0.11 1.555 mg/L

Total Recoverable Phenolics ND 0.014 0.014 mg/L

Characteristics of flowback water sampled at 1 day, 3 days, 5-6 days, and 10-12 

days following the hydraulic fracturing event are presented in Tables 20 and 21. The 

water is elevated in alkalinity with median values ranging from 725-1,200 mg/l. The 

water remains imbalanced with high levels of calcium and magnesium. Cations are 

dominated by sodium and calcium in this water. Anions are dominated by chloride. 

However, there is a fairly large sulfate component to the anionic balance, which has 
35

importance in the relative value of barium and strontium in the water. This topic is 

evaluated further in the discussion section.

Table 20 General Chemical Parameters, Barnett Day 1 and Day 3

LPG1,2,3,5 LPG 1,2,4

General Chemistry Day 1 Day 3 

Parameter Range Median Range Median Units

pH 6.7 - 8 7.2 6.5- 7.2 6.6 No Units

Acidity ND- ND ND ND- ND ND mg/L

Total Alkalinity 482- 1,590 980 236- 1,550 1,340 mg/L

Hardness as CaCO3 840- 2,800 2,200 3,000- 24,000 4,600 mg/L

Total Suspended Solids 48- 237 153 59- 120 89 mg/L

Turbidity 37- 266 130 104- 371 154 NTU

Chloride

3,330- 17,900 11,405 17,500- 49,000 21,400 mg/L

Total Dissolved Solids 5,850- 31,400 25,050 33,500- 96,900 37,200 mg/L

Specific Conductance 11,300- 59,000 55,550 71,400- 174,000 82,600 umhos/cm

Total Kjeldahl Nitrogen 16- 203 155 74- 239 215 mg/L

Ammonia Nitrogen 9- 223 186 143- 309 251 mg/L

Nitrate-Nitrite 0.024- 0.024 0.024 0.051- 0.051 0.051 mg/L

Nitrite as N 81.9- 107 94.45 85.7- 96.8 91.25 mg/L

Biochemical Oxygen Demand 89- 1,480 311 94- 290 244 mg/L

Chemical Oxygen Demand 850- 4,280 1,485 1,900- 5,850 2,290 mg/L

Total Organic Carbon (TOC) 34.7- 99.1 47.5 15.4- 19 17.4 mg/L

Dissolved Organic Carbon 30.6- 91.3 53.55 9.7- 23.2 17.6 mg/L

Oil & Grease (HEM) 5.6- 1720 862.8 26.7- 26.7 26.7 mg/L

Cyanide, Total 15.6- 15.6 15.6 ND- ND ND ug/L

Amenable Cyanide ND- ND ND ND- ND ND mg/L

Hexavalent Chromium 0.014- 0.16 0.0165 0.011- 0.042 0.02 mg/L

Dissolved Hexavalent Chromium 0.01- 0.08 0.03 ND- 0.15 0.08 mg/L

Bromide 34.3- 532 303.5 270- 448 399 mg/L

Fluoride 1.6- 30.6 4.75 4- 4.9 4.45 mg/L

Total Sulfide ND- ND ND ND- ND ND mg/L

Sulfate 259- 972 669 277- 1,010 585 mg/L

Total Phosphorus 0.37- 3.4 0.79 0.39- 0.66 0.525 mg/L

Total Recoverable Phenolics 0.034- 0.45 0.08 0.046- 0.13 0.088 mg/L
36

Table 21: Summary of General Chemistry of Flowback Water Days 5-6 and 10-12

General Chemistry

LPG 1,2,3,4

Day 5-6 

LPG 1,2,3,4

Day 10-12 

Parameter Range Median Range Median Units

pH 6.6- 7.2 7 6.5 7.2 7.05 No Units

Acidity ND- ND ND ND ND ND mg/L

Total Alkalinity 238- 1,630 1,007 215 1,240 725 mg/L

Hardness as CaCO3 3,400- 24,000 4,300 3,500 21,000 5,800 mg/L

Total Suspended Solids 37- 253 95 120 535 242 mg/L

Turbidity 2- 400 9 144 314 239 NTU

Chloride 16,700- 72,400 23,150 9,600 60,800 34,700 mg/L

Total Dissolved Solids 25,000- 98,900 37,800 16,400 97,800 50,550 mg/L

Specific Conductance 53,000 174,000 87,900 34,800 179,000 111,500 umhos/cm

Total Kjeldahl Nitrogen 28- 251 163 26 298 171 mg/L

Ammonia Nitrogen 30- 302 209 18 486 303 mg/L

Nitrate-Nitrite ND 0.023 0.0115 0.018 0.035 0.0265 mg/L

Nitrite as N 4.5- 96.3 50.4 3.5 38.1 4.7 mg/L

Biochemical Oxygen Demand 93- 323 207 101 2,120 582 mg/L

Chemical Oxygen Demand 2,440- 3,610 2,690 927 3,150 2,945 mg/L

Total Organic Carbon (TOC) 9.5- 26.7 15.5 6.2 36.2 9.75 mg/L

Dissolved Organic Carbon 6.6- 27.8 12.95 5.5 65.3 11.2 mg/L

Oil & Grease (HEM) 110- 110 110 88.2 1430 163.5 mg/L

Cyanide, Total 2.2- 17.9 10.05 6 6 6 mg/L

Amenable Cyanide ND- ND ND ND ND ND mg/L

Bromide 218- 690 571 117 798 589 mg/L

Fluoride 0- 5.3 2.55 3.5 12.8 3.8 mg/L

Total Sulfide ND- 0.8 NA ND ND ND mg/L

Sulfate 145- 1,300 1,055 120 1,260 709 mg/L

Total Phosphorus 0.41- 2.3 0.48 0.19 0.7 0.395 mg/L

Total Recoverable Phenolics 0.0075- 0.0081 0.0078 0.0093 0.23 0.11965 mg/L
37

Salt concentrations (TDS) in influent water and in flowback water generated over 

time from the 5 sampling Sites from the Barnett are tabulated in Table 22. As shown in 

Table 15, influent water contains moderate to low concentrations of salts. Following the 

use of this water for hydraulic fracturing, a flowback water stream that is collected from 

the well exhibits increasing concentrations of salts with time. These profiles of salt 

concentrations are similar to Figure 1. As expected, early flowback water emerging 

soon after the frac job is relatively low in TDS content; following the initial day, the 

concentration of total dissolved solids increases with time from low salt concentrations 

to a plateau of elevated salt levels as measured at 10 and 12 days. 

Table 22: Salt Concentrations (TDS, mg/l)

Day 0 Day 1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG 1 203** 31,400 33,500 39,500 48,900

LPG 2 203** 26,500 37,200 36,100 52,200

LPG 3 800* 5,850 25,000 30,000 16,400

LPG 4 800* 96,900 98,900 97,800

LPG 5 800* 23,600

* One Sample,** One Sample

Levels of total organic carbon (TOC) in the flowback water samples at 5-6 and 10-

12 days are lower than the TOC of the raw water. Organic components, as represented 

by Total Organic Carbon, remain fairly constant or decrease over time (Table 23. The 

TOC of the Barnett samples is generally lower than that of the Marcellus samples. 

Table 23: Total Dissolved Carbon Concentrations (TDS, mg/l)

Day 0 Day 1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG 1 124** 34 17 13 7

LPG 2 124** 36 15 10 6

LPG 3 143* 59 27 28 36

LPG 4 143* 19 18 12

LPG 5 143* 99

* One Sample,** One Sample
38

The same observation cannot be made in comparing biochemical oxygen demand 

(BOD) values in flowback water with the BOD of the influent water streams (Table 24). 

The BOD data are quite erratic, with sudden spikes to values exceeding 645-2000 mg/l. 

The moderate levels of BOD in the influent waters may have been due to recycling of 

recovered water from other frac jobs. 

 Table 24: BOD (TDS, mg/l)

Day 0 Day 1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG 1 245** 243 290 319 2120

LPG 2 245** 374 244 323 928

LPG 3 130* 90 94 645 101

LPG 4 130* 94 92 236

LPG 5 130* 1480

* One Sample,** One Sample

COD data (Table 25) shows steady increase with time, roughly following the total 

salts concentration, indicating that much of the COD may be associated with inorganic 

matter in the water. 

Table 25: COD (TDS, mg/l)

Day 0 Day 1 Day 3 Day 5 Day 6 Day 7 Day 10 Day 12

LPG 1 559** 1610 1900 2620 2920

LPG 2 559** 1360 2290 2440 3070

LPG 3 829* 850 2760 7870 927

LPG 4 829* 5850 360 3150

LPG 5 829* 4280

* One Sample,** One Sample

Organic Compounds

As with the Marcellus characterization, organic compounds determined in the 

characterization of water samples fell into the categories of volatile organics, semi 

volatile organics, chlorinated pesticides, organophosphorus pesticides, and 
39

polychlorinated biphenyls. The following sections summarize the results among all five 

of the categories of analysis. 

Volatile Compounds

As presented in Table 1, samples collected from Sites 1-5 were analyzed for 70 

volatile compounds of highly varied chemical characteristics, including the volatile 

hydrocarbon constituents that are normally found in produced water (such as benzene, 

toluene, ethylbenzene, and xylenes – or BTEX, and naphthalene) as well as 

constituents not known to be associated with conventional produced water such as 

chlorinated solvents and halogenated aromatics. The volatile organic content from the 

two raw water samples are presented in Table 26. Only traces of napthlene, toluene, 

and benzene were identified in the sample for Sites LPG 1 and LPG2. 

Table 26: Volatile Organics in the Influent Water Samples

Volatiles (μg/L) LPG 3,4,5 LPG 1,2 Average Units

Naphthalene ND 1.3 NA μg/L

Benzene ND 2 NA μg/L

Toluene ND 3 NA μg/L

A summary of the results for volatile compound determinations performed 

recovered flowback water is shown in Table 27. Traces of benzene and other alkylated 

benzyl isomers were present in the recovered water. The relative concentrations did 

not appear to change with time after fracture and appeared to fluctuate fairly randomly. 

All data were, therefore, consolidated to present the range of results encountered in all 

16 samples. It is important to note that of all the components measured in the test 

protocol, only 8 compounds common to waters generated from petroleum and gas sites 

were detected. No compound was observed in all 16 samples. The most commonlyencountered constituents were the BTEX and similarly related alkyl-benzene isomers. 

Traces of acetone, a commonly used cleaning fluid, were also found at measurable 

concentrations. 
40

Table 27: Summary Volatiles Data; All Site Samples (Days 1-12, Total = 16 

Samples)

Volatiles Data (μg/L)

Number of

Observations Range Median Average

Isopropylbenzene 2 0.8 - 69 35 35

Acetone 9 27 - 540 110 145

Naphthalene 12 8.3 - 84 22 27

1, 3, 5 - Trimethylbenzene 12 6.4 - 300 15 59

1, 2, 4 - Trimethylbenzene 13 6.9 – 1,200 37 173

Xylenes (total) 14 43 – 1,400 360 425

Benzene 15 49 – 5,300 680 1,198

Ethylbenzene 15 2.2 - 670 29 74

Toluene 15 79 – 8,100 760 1,246

The concentrations of 70 compounds were evaluated in the 16 test samples for a 

total of 1120 evaluations. Most tests were reported as non-detectable (1013 

evaluations). Ninety-two observations were below 1 ppm and only 15 observations 

were above 1 ppm. Chlorinated, brominated, or other man-made compounds were not 

detected. More than 90 percent of all constituent determinations, on average, were at 

Figure 4: Number of Detectable and Non-Detectable Tests for Volatile 

Compounds.

Observations of Detectable Volatiles

 in 16 Site Samples

1120

1013

92

15

0

200

400

600

800

1000

1200

All Tests Non-Detects Trace

(<1ppm)

>1 ppm Observations
41

non-detectable levels and less than 1.5 percent of all constituent determinations were 

above 1 ppm (Figure 4 above). 

Semi volatile Compounds

A total of 112 semi volatile organic compounds (as listed in Table 1) were included 

in the analysis of influent water and in flowback water samples. A summary of the 

results of semi volatile determinations in the two raw water samples is presented in 

Table 28. The sample from Sites LPG 3,4,and 5 had traces of PAH, and traces of two 

phthalate esters and two chlorinated hydrocarbons. Water from Site LPG 1 and 2 

water had only a single report of pyridine.

Table 28: Semi volatile Compounds in the Influent Water 

Semi-Volatiles (μg/l) LPG 3,4,5 LPG 1,2 Average

Benzo (a) anthracene 1.3 ND NA

Benzo (a) pyrene 1.1 ND NA

Benzo (b) fluoranthene 1.3 ND NA

Benzo (ghi) perylene 1.1 ND NA

Benzo (k) fluoranthene 0.95 ND NA

bis (2 - Ethylhexyl) phthalate 36 ND NA

Butyl benzyl phthalate 2 ND NA

Chrysene 1.2 ND NA

Dibenz (a, h) anthracene 0.98 ND NA

Di - n butyl phthalate 1.9 ND NA

2, 6 - Dichlorophenol 2 ND NA

Fluoranthene 1 ND NA

Hexachlorobenzene 0.8 ND NA

Indeno (1, 2, 3 - cd) pyrene 0.91 ND NA

Pentachlorophenol 0.69 ND NA

Phenanthrene 1.2 ND NA

Pyrene 1 ND NA

Pyridine 0.96 40 20.5
42

A summary of the results for semi-volatile compound determinations performed on 

the 16 site samples is shown in Table 29. Of the 112 compounds in the sample set, 

about 70% were not detected in any sample. Of the 32 compounds observed, about 1/3 

of these were incidental detections in one of the 16 samples. All compounds detected 

are naturally occurring in petroleum. Pyridine is a nucleophile that is used widely in the 

manufacture of certain types of chemicals and pharmaceuticals and its presence may 

be due to its use as a precursor in the manufacture of one of the hydraulic fracturing 

additives. In general, nearly all of the semi volatile determinations were either nondetect (> 96% of the measurements) or at low trace levels (Figure 5 above). 

Number of Observations

 from 16 Site Samples

All Tests, 1792

Non-Detects, 

1595

Trace(<1ppm), 

163

>1ppm, 4

0

200

400

600

800

1000

1200

1400

1600

1800

2000

All Tests Non-Detects Trace(<1ppm) >1ppm

Observations

Figure 5: Distribution of Observations of Semi volatile Organics in 16 Site Samples
43

Table 29:Semi-volatiles Data from 16 Site Samples (Days 1-23) All Five Sites

Semi-volatiles (μg/l)

Number of 

Observations Range Median Average

Diphenylamine 2 0.6 - 10.0 5.3

Benzidine 1 ND - 35

1, 4 - Dioxane 7 3.1 - 12 5.4 6.5

1, 2 - Diphenylhydrazine 2 0.5 - 7.8 4.2

Acetophenone 1 ND - 4.6

Benzo (a) anthracene 1 ND - 17.0

Benzo (a) pyrene 1 ND - 130.0

Benzo (b) fluoranthene 2 0.5 - 84.0 42.2

Benzo (ghi) perylene 2 0.7 - 84.0 42.3

Benzo (k) fluoranthene 2 0.6 - 65.0 32.8

Benzyl alcohol 8 14.0 - 200 27.0 81.5

bis (2 - Ethylhexyl) phthalate 5 4.8 - 490 33 210

Butyl benzyl phthalate 4 1.9 - 110 12.6 34.3

Chrysene 2 0.57 - 240 120

Dibenz (a, h) anthracene 2 3.2 - 150 77

Di - n butyl phthalate 4 1.5 - 120 22 41

2, 4 - Dichlorophenol 1 ND - 15

2, 4 - Dimethylphenol 8 8.3 - 21 15.5 14.5

Di - n - octyl phthalate 1 ND - 270

Fluoranthene 1 ND - 0.18

Fluorene 6 0.46 - 1.3 0.725 0.8

Indeno (1, 2, 3 - cd) pyrene 2 2.9 - 140 71

2 - Methylnaphthalene 16 5.4 - 20,000 22.5 1362

2 - Methylphenol 15 5.8 - 76 31 28.3

3 - Methylphenol & 4 - Methylphenol 15 7.8 - 100 44 41

Naphthalene 16 4.8 - 3100 22 238

N - Nitrosodiphenylamine 2 7.8 - 10 8.9

N - Nitrosomethylethylamine 1 ND - 410

Phenanthrene 14 0.52 - 1400 1.3 107

Phenol 7 17 - 93 68 63

Pyrene 1 ND - 0.18 0.2

Pyridine 15 100 - 670 500 413

Pesticides

Determinations of the 20 chlorinated pesticides and 3 organophosphorus pesticides 

on 5 site samples and two source waters (Day 0) are listed in Table 30. A single 

incidental measurement of less than 0.1 ppb was detected on day 1 from LPG 1. All 

other determinations for chlorinated pesticides were measured as non-detect. This 
44

would suggest that no chlorinated pesticides were introduced with the additives with the 

influent water during well completions. 

Table 30: Summary Pesticide Data

Site LPG1 LPG2 LPG3 LPG4 LPG5

Sample Day Day 1 Day 0 Day 0 Day 7 Day 1 Day 5 Day 0

Chlorinated Pesticides

Chlordane (Technical) ND ND ND ND ND ND ND

alpha - BHC ND ND ND ND ND ND ND

beta - BHC 0.073 ND ND ND ND ND ND

delta - BHC ND ND ND ND ND ND ND

gamma - BHC (Lindane) ND ND ND ND ND ND ND

Heptachlor ND ND ND ND ND ND ND

Aldrin ND ND ND ND ND ND ND

Heptachlor epoxide ND ND ND 0.43 ND ND ND

Endosulfan I ND ND ND ND ND ND ND

Dieldrin ND ND ND ND ND ND ND

4, 4' - DDE ND ND ND ND ND ND ND

Endrin ND ND ND ND ND ND ND

Endrin ketone ND ND ND ND ND ND ND

Endrin aldehyde ND ND ND ND ND ND ND

Endosulfan II ND ND ND ND ND ND ND

4, 4' - DDD ND ND ND ND ND ND ND

Endosulfan sulfate ND ND ND ND ND ND ND

4, 4' - DDT ND ND ND ND ND ND ND

Methoxychlor ND ND ND ND ND ND ND

Toxaphene ND ND ND ND ND ND ND

Organophospates

Thionazin ND ND ND ND ND ND ND

Ethyl parathion ND ND ND ND ND ND ND

Tetraethyldithiopyrophosphate ND ND ND ND ND ND ND
45

Polychlorinated Biphenyls (PCBs)

Determinations of the 7 polychlorinated biphenyl compounds (arochlors) listed in Table 

1 were conducted on the two influent waters and Sites 2,4, and 5. As seen from these 

graphs, all determinations for PCBs were measured as non-detect. This would suggest 

that no PCBs were introduced with the additives with the influent water during well 

completions. 

Table 31 : PCB Data

Source Water

Day 0

LPG1

Day

LPG2

Day

LPG3

Day

LPG 3,4,5 LPG 1,2 1 5 1 5 1 7

Arochlor 1016 ND ND ND ND ND ND ND ND

Arochlor 1221 ND ND ND ND ND ND ND ND

Arochlor 1232 ND ND ND ND ND ND ND ND

Arochlor 1242 ND ND ND ND ND ND ND ND

Arochlor 1248 ND ND ND ND ND ND ND ND

Arochlor 1254 ND ND ND ND ND ND ND ND

Arochlor 1260 ND ND ND ND ND ND ND ND

Metals

Unlike the organic constituents that do not change much with time, the metals 

concentrations tend to increase with time from fracture and follow the general trend for 

TDS. A summary of metal concentrations in the two influent water samples is 

presented in Table 32. 

The total metals content of the Day 1 and Day 3 samples are summarized in Table 

34. As seen in this table, sodium is the major cation in all of the samples, followed by 

concentrations in some samples of calcium, magnesium and barium that will need to be 

monitored for purposes of scale control in some locations. 

The total metal content of the Day 5-6 and Day 10-12 samples are presented in

Table 35. Since strontium is present in flowback waters at concentrations between 345 

to 4,830 mg/l in the 5-day flowback samples, it will be important for operators to 

implement procedures to prevent the formation of strontium-bearing scale. Iron levels in 
46

the range of 10 to 180 mg/l may also need to be watched and mitigated in order to 

prevent operational difficulties at a number of well completion locations. 

Heavy metals of toxicological concern that are often associated with urban industrial 

activity (including chromium, copper, nickel, zinc, lead, cadmium, mercury and arsenic) 

are at very low levels in all of the shale gas water samples. 

Table 32: Total Metals in Influent Water Samples

Total Metals LPG 3,4,5 LPG 1,2 Average Units

Aluminum 0.525 0.604 0.564 mg/L

Antimony ND ND mg/L

Arsenic ND ND mg/L

Barium 0.0527 2.66 1.356 mg/L

Beryllium ND ND mg/L

Boron 0.509 0.124 0.317 mg/L

Calcium 13.1 17.1 15.1 mg/L

Cadmium ND ND mg/L

Cobalt ND ND mg/L

Chromium ND 0.0064 0.0064 mg/L

Trivalent Chromium ND 0.0026 0.0026 mg/L

Copper ND ND mg/L

Iron 1.68 1.18 1.43 mg/L

Lead 0.0127 ND mg/L

Lithium 0.0464 ND mg/L

Magnesium 1.57 11.5 6.535 mg/L

Manganese 0.0359 0.0478 0.042 mg/L

Molybdenum ND ND mg/L

Nickel ND ND mg/L

Potassium 3.5 4.46 4 mg/L

Sodium 278 81.3 179.6 mg/L

Selenium ND ND mg/L

Tin ND ND mg/L

Strontium 0.244 1.3 0.77 mg/L

Titanium ND ND mg/L

Thallium ND ND mg/L

Zinc 0.0281 ND mg/L

Mercury ND ND mg/L
47

Table 33: Metals Data in the Barnett Samples

Metals Data (mg/l)

LPG1,2,3,5 / Day 1 LPG 1,2,4 Day 3

Range Median Range Median

Aluminum 0.114- 0.572 0.495 0.34- 0.49 0.34

Antimony ND ND ND ND

Arsenic ND ND ND 0.03

Barium 0.053 - 3.31 1.50 1.63 - 15.0 2.86

Beryllium ND ND ND

Boron 0.51 - 39.1 23.5 25.6 - 29.6 29.3

Calcium 13 - 768 564 753 - 6,290 1,270

Cadmium ND - 0.000 0.00 - 0.00 0.00

Cobalt 0.006 - 0.028 0.014 0.01 - 0.01 0.01

Chromium 0.011 - 0.066 0.030 0.02 - 0.06 0.04

Trivalent Chromium 0.003 - 0.014 0.008 0.02 - 0.02 0.02

Copper 0.087 - 0.131 0.109 0.04 - 0.04 0.04

Iron ND 18.9 - 43.6 37.4

Lead 0.013 - 0.034 0.013 ND

Lithium 0.046 - 10.8 9.01 10.7 - 32.3 13.1

Magnesiium 2 - 116 89 113 - 713 199

Manganese 0.036 - 1.98 0.711 0.35 - 1.63 0.66

Molybdenum 0.015 - 0.066 0.043 0.02 - 0.08 0.07

Nickel 0.029 - 0.036 0.033 0.02 - 0.02 0.02

Potassium 4 - 216 111 192 - 662 247

Sodium 278 - 12,200 7805 11,800 - 23,700 14,100

Selenium ND 0.03 - 0.03 0.03

Tin 0.004 - 0.004 0.004 0.03 - 0.03 0.03

Strontium ND - 206 132 220 - 1170 282

Titanium ND ND 0.00

Thallium ND 0.05 - 0.05 0.05

Zinc 0.028 - 0.560 0.202 0.14 - 0.18 0.15

Mercury ND ND
48

Table 34: Total Metals Data Days 5-6 and 10-12

LPG 1,2,3,4 / Day 5-6 LPG 1,2,3,4 Day 10-12 

Range Median Range Median

Aluminum 0.37 - 1.64 0.39 0.37 - 2.21 0.43

Antimony ND ND ND

Arsenic ND ND ND

Barium 1.48 - 16.8 2.19 0.93 - 17.9 3.6

Beryllium ND - ND ND ND

Boron 18.0 - 37.1 31.2 7.0 - 31.9 30.3

Calcium 944 - 6,680 1,290 1,110 - 6,730 1,600

Cadmium ND ND

Cobalt 0.01 - 0.01 0.01 0.01 - 0.01 0.01

Chromium 0.01 - 0.11 0.03 0.01 - 0.12 0.03

Trivalent Chromium 0.03 - 0.11 0.07 ND 0.03 0.01

Copper 0.37 - 0.37 0.37 0.06 - 0.52 0.29

Iron 11.8 - 76.7 17.25 12.1 - 93.8 24.9

Lead ND ND 0.01 - 0.02 0.02

Lithium 5.10 - 35.6 14.80 2.56 - 37.4 19.0

Magnesiium 145 - 757 182 149 - 755 255

Manganese 0.32 - 1.93 0.42 0.25 - 2.20 0.86

Molybdenum 0.02 - 0.04 0.04 0.02 - 0.03 0.02

Nickel 0.02 - 0.03 0.02 0.03 - 0.05 0.04

Potassium 85 - 725 284 80 - 750 316

Sodium 7,540 - 25,300 15,950 4,370 - 28,200 18,850

Selenium ND 0.03 - 0.04 0.03

Tin ND ND

Strontium 67 - 1,320 330 48 - 1,550 529

Titanium 0.02 - 0.02 0.02 0.02 - 0.03 0.02

Thallium ND ND ND - 0.14

Zinc 0.09 - 0.31 0.11 0.10 - 0.36 0.15

Mercury ND ND

DISCUSSION

This report brings to light compositional features of flowback water that are 

important when considering the possible common and uncommon impacts for this 

wastewater. Common consideration for treatment considers parameters such as 

biological oxygen demand, total carbon, total kjdehal nitrogen, oil and greases, etc. It is 

useful to present a quick summary of these parameters. The following two plots show 

the median observed common pollutants for the Marcellus samples (Figure 6) and for 

the Barnett samples (Figure 7). 
49

Median Observed Conventional Contaminants

Marcellus

0

50

100

150

200

250

300

350

Influent Day 1 Day 5 Day 14 Day 90

mg/l

BOD TOC Oil & Grease TKN

Figure 6: Median Common Components of Flowback Water from the 

Marcellus Samples

Median Observed Conventional Contaminants

Barnett

0

100

200

300

400

500

600

700

800

900

1000

Influent Day 1 Day 3 Day 5-6 Day 10-12

mg/l

BOD

TOC 

Oil $& Grease

TKN

Figure 7: Median Observations of Common Contaminants in the 

Barnett Samples
50

Heavy Metals

Heavy metals of toxicological concern that are often associated with urban industrial 

activity (including chromium, copper, nickel, zinc, lead, cadmium, mercury and arsenic) 

are at very low levels in all of the shale gas water samples compared to levels reported 

for municipal wastewaters. Table 35 presents median values from the 5-Day Flowback 

samples which are compared to median heavy metals concentrations measured in 

sewage sludges (biosolids) generated by Penn State for the State of Pennsylvania 

(Steinhouwer, 2000). The comparison shows that the levels of heavy metals of concern

are 100 to 10,000 times higher in municipal biosolids (sewage sludges that are routinely 

transported across communities to disposal sites) than the levels measured in shale gas 

waters. 

Table 35. Comparisons of Median Metals Levels in Shale Gas Waters with Municipal 

Biosolids (Sewage Sludge)

Metal 5-day Flowback Sewage Sludge* Units

Chromium 0.015 35 mg/l

Copper 0.029 511 mg/l

Nickel < 0.0004 22.6 mg/l

Zinc 0.156 705 mg/l

Lead < 0.0021 65 mg/l

Cadmium < 0.0001 2.3 mg/l

Mercury <0.0002 1.5 mg/l

Arsenic 0.029 3.6 mg/l

* Penn State study reporting median heavy metal content values for Pennsylvania publicly owned 

treatment works (POTW) biosolids. Stehauwer, et al., 2000. 

Total Dissolved Solids, Major Cations and Anions

The tendency for the flow rate of flowback water to decrease, and the total 

dissolved solids content to increase with time, provides opportunity to capture and reuse 

early flowback for reuse. The major challenge to the realization of this opportunity is the 

ultra-high concentration of divalent cations, which have tendencies to cause precipitates 

and scale in process equipment. 

The seven major cations encountered in the flowback waters are sodium, calcium, 
51

strontium, potassium, magnesium, iron, barium, and lithium. Of these cations; calcium, 

barium, strontium, magnesium, and iron are notorious scale formers. The seven major 

anions measured in these waters are chloride, bicarbonate, bromide, fluoride, sulfide, 

sulfate, and phosphate. Of these anions, carbonate species, sulfate, and phosphate 

are known to be potential scale formers.

Figure 8 is a distribution profile of the relative abundance of the major cations in all 

samples from the Marcellus and the Barnett. Figure 9 is a distribution of the relative 

abundance of the anions. The calculation for these figures was as follows. Each 

sample (60 from Marcellus, 19 from Barnett) was treated individually. The value of the 

each cation species in the individual was compared to the sodium content of the 

sample, based on the equivalent weight of each cation. The value of the individual 

anion species was compared to the chloride content. (Note: this presentation considers 

phosphorous measurements to represent P as phosphate). The equivalent ratio of an 

ion (example calcium to sodium) from each sample was pooled (60 samples from 

Marcellus and 19 from the Barnett). The data in the figures represents the median ratio 

from each pool. 

Most of the cation charge is carried by sodium. The proportion of sodium (87% of 

cation equivalents) in the Barnet samples is somewhat higher than the Marcellus 

samples (74% of cation equivalents). Chloride is the most common anion, representing 

more than 93% of the anionic content in the Barnett and 99% in the Marcellus samples. 

Sodium and Chloride are not shown in Figures 8 and 9 in order to better observe the 

trends in the less concentrated species.

Calcium is the second most abundant cation, representing about 22% of the 

cationic charge in the Marcellus and about 9% in the Barnett samples. This difference 

may, in part be due to the relatively higher content of carbonate alkalinity in the Barnett 

than in the Marcellus. Calcium also precipitates as a sulfate. The relative sulfate 

concentration in the Barnett 30 times greater than in the Marcellus. This also suggests a 

reasonable expectation why the calcium in the Barnett is less abundant than in the 

Marcellus samples. Calcium is stable at pH< 6. One potential means of handling 

calcium is by addition of acid to stabilize the calcium. The modest bicarbonate 

concentration in both sample bases indicates that there is a relatively low buffering 
52

capacity. A small acid addition should be sufficient to perform this procedure; 

therefore, the use of acidification would be very economical for the stabilization (i.e. 

solubilization) of calcium in the flowback waters of the Barnett and Marcellus Shale 

Plays. 

Strontium carries 1-2 % of the cationic charge in the flowback waters. Strontium is 

known to co-precipitate with calcium and barium, either as a carbonate or a phosphate, 

or a sulfate. Any pretreatment or reuse option should be designed to handle strontium.

Potassium is the fourth most abundant cation, but should not pose any treatment 

problems. In advanced separation processing, potassium is expected to behave much 

like sodium. 

Magnesium is about as abundant as potassium. Magnesium precipitates at high pH 

(>11) as a hydroxide, or in phosphate and ammonia rich waters as struvite. These 

conditions will not likely be found in these waters. 

Iron (calculated herein as the ferrous form) will precipitate at pH 5 as a hydroxide. 

With oxygen present, iron will convert to the ferric form and more readily precipitate at 

lower pH. A standard means of controlling iron is aeration followed by caustic addition 

Relative Abundance (%) of Cation Equivalence 

0.01

0.10

1.00

10.00

100.00

Calcium

Strontium

Potassium

Magnesiium

Iron

Lithium

Barium

Percent of Cationic Charge (equivalents)

Barnet (Note: Sodium = 87%)

Marcellus (Note: Sodium = 73.5%)

Figure 8: Relative Abundance of Cations in Flowback Waters
53

and settling. Iron is also biologically active, inviting many different types of surface 

active bacteria that catalyze many redox reactions. These reactions may involve 

oxygen, carbonate, organic carbon, sulfate, sulfur, and sulfide. 

Lithium is present in these waters, but should not interfere with any treatment 

process. In advanced separation processing, this light metal is expected to behave 

much like sodium and potassium. 

Barium readily precipitates as a sulfate. It is interesting to note that the Barnett 

water contains much more sulfate than the Marcellus water. This may be one reason 

why the barium content of the Barnett water has relatively less barium than the 

Marcellus water. 

Relative Abundance (%) of Anion Equivalence

0.001

0.010

0.100

1.000

10.000

Sulfate Bicarbonate Bromide Fluoride Sulfide Phosphate

Barnett (Note Chloride > 93%)

Marcellus (Note: Chloride >99%)

Figure 9: Relative Abundance of Anions in Flowback Waters
54

Implications for Fate and Transport 

As seen in Table 1, the list of measurements and determinations that were pursued 

in this study were very exhaustive but highly useful in establishing an information base 

to define a chemical fingerprint associated with flowback waters from these geologic 

formations. Much of the expense and time required for water characterization has 

arisen from the extensive effort to analyze the samples for large numbers of volatile and 

semi volatile organic compounds (including chlorinated pesticides, organophosphorus 

pesticides and polychlorinated biphenyls); the information base developed in this 

project strongly suggests that this level of water characterization in the future is not 

necessary and that monitoring should be focused on measuring constituents that are 

likely to be present. 

A number of observations that are relevant to fingerprinting and to the fate and 

transport of constituents can be made from consideration of the information base 

assembled from the first 19 locations in the Marcellus and the first five locations in the 

Barnett. First, there is clear indication that halogenated hydrocarbon compounds 

(among volatile, semi volatile, pesticides and PCB categories) and nearly all of the 

polynuclear aromatic hydrocarbons (of 3 rings and above) are not a part of detectable 

components in flowback waters. Volatile and semi volatile organic constituents that are 

normally found in conventional produced waters, such as BTEX, methylated benzenes, 

naphthalene, naphthenic acids, volatile acids, simple alkanes, etc., are also found in 

flowback waters and in influent waters for frac jobs that utilize flowback water reuse. 

However, in terms of fate and transport in the environment, many volatile and semi 

volatile organics present in shale gas waters are at modest concentrations (most 

compounds are below 1 ppm). The challenge, therefore, is to choose an alternate 

parameter that can be used to quickly detect any small release of flowback water that 

may occur in the course of storage or handling. 

A more practical approach might be to use chloride analyses of samples to monitor 

fate and transport of flowback/produced waters. Chloride has been used as a 

conservative tracer in hydrogeochemical studies for decades and is well documented in 

the literature (Clement et al., 2000; Farrell et al., 1994; Lamontagne et al., 2005; Negrel 

and Lachassagne, 2000; Nelson et al., 2001; Paine, 2003; van Breukelen et al., 1998). 
55

A general overview of the processes controlling the movement of solutes in the 

subsurface is provided below. 

Fate and transport of constituents in the soil/rock/water system is governed by four 

fundamental processes: advection, dispersion, retardation, and decay. Advection is 

simply the mass movement of a solute along with groundwater and is modeled by 

Darcy’s Law. Dispersion is a mathematical description of diffusion and mechanical 

mixing of a solute in a system. Diffusion is modeled using Fick’s first and second law. 

Dispersion is an empirical correction factor controlled by the physical properties of the 

soil/rock matrix (porosity, grain size, sorting, etc) and scale of the system. Retardation is 

the process by which non conservative solutes interact with the soil/rock and their 

movement downgradient is subsequently slowed. It is modeled by a linear equation that 

is a function of porosity, moisture content, bulk density, and the humic organic matter 

content. Examples of retardation reactions are adsorption-desorption, ion exchange, 

precipitation-dissolution, and oxidation-reduction reactions. Decay is the process by 

which a solute is removed from the system due to chemical reactions, biological 

reactions, and/or radioactive decay and is modeled using the appropriate equation for 

the reaction occurring in the system. 

Conservative solutes are ones that can be modeled using only advection and 

dispersion. Common examples are chloride and bromide, but bromide levels in the 

samples collected as part of this study were several orders of magnitude lower than 

chloride levels. Non-conservative solutes can only be modeled using advection, 

dispersion, retardation, and/or decay. Examples of non-conservative solutes are 

volatile/semi volatile organics (e.g. benzene, toluene, PAHs, PCBs, etc.), sulfate, iron, 

and many others. Non-conservative species subsequently migrate slower throughout 

the subsurface than do conservative tracers and therefore are inappropriate to use as 

indicators of Marcellus Shale flowback water impact to a system. Nearly all classes of 

volatile and semi volatile organics discussed in this report have been shown to be 

sequestered to various types of soils, thereby significantly retarding their mobility in the 

environment (Linz and Nakles, 1997). 

Chloride, on the other hand, is more mobile and has considerable potential as an 

early sentinel indicator of flowback water impacts due to a number of advantages. In 
56

addition to being conservative (by virtue of its non-volatile, non-sequestering, nonreactive property), chloride is usually present in relatively high concentrations ranging 

from 10,000 to 200,000 mg/l, ten to a hundred times the concentration of most 

inorganics and more than a million times the levels of most volatile and semi volatile

organic constituents. Chloride is also easily measured with field kits that can determine 

the presence of this anion with small samples, and verified in its presence with simple 

conductivity instruments. Due to its high concentration and its ubiquitous presence in 

flowback waters, chloride anion is an excellent monitoring tool for even the smallest 

leaks of flowback water into the environment. 
57

CONCLUSIONS

With the completion of this sampling and analysis effort, the following conclusions 

can be drawn from the results: 

1. General chemistry characterization of flowback water indicates that values for 

pH, alkalinity, total dissolved solids, total organic carbon, oils and greases and 

other parameters from general water characterization are well within the normal 

ranges reported for conventional produced waters. Flowback water appears 

similar in composition to conventional produced water, even in the presence of 

additives employed for performing hydraulic fracturing. 

2. Shale gas flowback water cations are dominated by sodium and calcium; anions 

are dominated by chloride.

3. Metals in flowback water are well within the ranges for normal produced waters. 

Industrial heavy metals (e.g. chromium, copper, nickel, zinc, lead, cadmium, 

arsenic and mercury) are a small fraction (less than 1 percent) of the heavy 

metals content found in municipal biosolids generated from POTW’s. 

4. Among volatile organic compounds, more than 93% of these constituents were 

found at non-detectable levels and less than 1% were above 1 ppm for any of the 

5 sampling events among 19 locations. The data indicate that the constituents 

above 1 ppm are those that are a normal part of produced waters associated with 

natural gas operations (such as xylenes, toluene and naphthalene). 

5. Among semi volatile organic constituents, more than 96% of all determinations 

were at nondetectable levels and less than 0.1% of these constituents were 

above 1 ppm. 

6. All chlorinated pesticides, organophosphorus pesticides and polychlorinated 

biphenyls were determined to be at non-detect levels for all tested samples of 

influent water and flowback waters. 

7. Virtually, all man-made halogenated organic compounds were at non-detect 

levels; the same was true for organophosphorus pesticides. This strongly 

suggests that additives that are blended with influent waters do not contain 

concentrations of man-made organic chemicals of concern. 
58

8. The results of this shale gas water characterization effort indicate that pesticides, 

PCBs, a large fraction of the volatile and semi volatile constituents should be 

considered to be unnecessary for the sampling and analysis of flowback waters 

in the future. 

9. Determination of factors that affect levels of organic and inorganic compounds 

could potentially be determined through a correlation of flowback water 

composition with the key shale gas development parameters of geographic area, 

depth of wells, completion methods, etc.
59

REFERENCES CITED

APHA. 1992. “Standard Methods for the Examination of Water and Wastewater”, 18th

Edition (SM18). 

APHA. 1999. “Standard Methods for the Examination of Water and Wastewater”, 20th

Edition (SM20). 

Clark, C.E. and J.A. Veil. 2009. Produced Water Volumes and Management Practices 

in the U.S. USDOE/Argonne Laboratories Report No. ANL/EVS/R-09/1. 

Clement, T.P., Johnson, C.D., Sun, Y., Klecka, G.M., and Bartlett, C., 2000, Natural 

attenuation of chlorinated ethene compounds; model development and field-scale 

application at the Dover site: Journal of Contaminant Hydrology, v. 42, p. 113-140.

Engelder, T., and G.G. Lash. 2008. Marcellus Shale Play’s Vast Resource Potential 

Creating a Stir in Appalachia. The American Oil & Gas Reporter, May. 

Farrell, D.A., Woodbury, A.D., and Sudicky, E.A., 1994, The 1978 Borden tracer 

experiment; analysis of the spatial moments: Water Resources Research, v. 30, p. 

3213-3223.

Gaudlip, A.W., L.O. Paugh, and T.D. Hayes. 2008. Marcellus Shale Water 

Management Challenges in Pennsylvania. SPE Paper No. SPE–119898-PP, Society of 

Petroleum Engineers.

Hayes, T.D. 2009. Sampling and Analysis of Water Streams Associated with the 

Development of Marcellus Shale Gas, Final Report to the Marcellus Shale Coalition. 

Gas Technology Institute, Des Plaines, Il.

Kharaka, Y.K. and C.A. Rice. 2004. “Organic and Inorganic Species in Produced 

Water: Implications for Water Reuse”, Proceedings of the Natural Gas Technologies 

Conference, Phoenix, Feb 8-10. Available from the Gas Technology Institute

Lamontagne, S., Leaney, F.W., and Herczeg, A.L., 2005, Groundwater-surface water 

interactions in a large semi-arid floodplain; implications for salinity management: 

Hydrological Processes, v. 19, p. 3063-3080.

Linz, D.G. and D.V. Nakles. 1997. Environmentally Acceptable Endpoints in Soil. 

American Academy of Environmental Engineers, United Book Press, Inc., Baltimore, 

MD. 

Negrel, P., and Lachassagne, P., 2000, Geochemistry of the Maroni River (French 

Guiana) during the low water stage; implications for water-rock interaction and 

groundwater characteristics: Journal of Hydrology, v. 237, p. 212-233.

Nelson, M.D., Parker, B.L., Al, T.A., Cherry, J.A., and Loomer, D., 2001, Geochemical 

reactions resulting from in situ oxidation of PCE-DNAPL by KMnO (sub 4) in a sandy 

aquifer: Environmental Science & Technology, v. 35, p. 1266-1275.

Paine, J., 2003, Determining salinization extent, identifying salinity sources, and 

estimating chloride mass using surface, borehole, and airborne electromagnetic 

induction methods: Water Resources Research, v. 39, p. 10.
60

Stehouwer, R.C., A.M. Wolf, and W.T. Doty. 2000. “Chemical Monitoring of Sewage 

Sludge in Pennsylvania: Variability and Application Uncertainty.” J. Environ. Qual. 29: 

1686 – 1695. 

USEPA. 1984. “Methods for Organic Chemical Analysis of Municipal and Industrial 

Wastewater”, 40CFR, Part 136, Appendix A, October 26. 

USEPA. 1983. “Methods for Chemical Analysis of Water and Wastes”, EPA-600/4-79-

020, March. 

USEPA. 1986. Test Methods for Evaluating Solid Waste, Physical/Chemical Methods”, 

Third Edition, November (SW846). 

USGS. 2009. USGS Produced Water Database. Available at: 

http://energy.cr.usgs.gov/prov/prodwat/intro.htm . 

van Breukelen, B.M., Appelo, C.A.J., and Olsthoorn, T.N., 1998, Hydrogeochemical 

transport modelling of 24 years of Rhine water infiltration in the dunes of the Amsterdam 

water supply: Journal of Hydrology, v. 209, p. 281-296.
61

ACKNOWLEDGEMENTS

The data presented in this report from the Marcellus Shale was generated from a 

project conducted in 2009 under the funding of the Marcellus Shale Coalition. A 

summary of the report is available from Gas Technology Institute upon request (Hayes, 

2009). 
62

APPENDIX A: FIELD SAMPLING AND ANALYSIS PLAN (FSAP)
Appendix A

Field Sampling and Analysis Plan (FSAP)
FIELD SAMPLING AND ANALYSIS PLAN

DEVONIAN SHALE FLOW BACK WATER 

CHARACTERIZATION STUDY

Prepared by

Appalachian Shale Water Conservation and Management Committee

December 2008
TABLE OF CONTENTS

1.0 INTRODUCTION ................................................................................................... 3

1.1 PURPOSE ............................................................................................................ 3

1.2 DATA OBJECTIVES .......................................................................................... 3

1.3 BACKGROUND.................................................................................................. 3

2.0 CHARACTERIZATION STUDY OF FLOW BACK WATER............................. 5

2.1 Sampling and Analyses........................................................................................ 5

3.0 SAMPLING PROTOCOLS..................................................................................... 7

3.1 PROJECT INITIATION ...................................................................................... 7

3.2 DOCUMENTATION........................................................................................... 7

3.2.1 Field Logbook............................................................................................... 7

3.2.2 Chain-of-Custody Form................................................................................ 8

3.3 SAMPLE DESIGNATION AND IDENTIFICATION ....................................... 8

3.4 SAMPLE MANAGEMENT AND SHIPMENT ................................................. 9

4.0 SAMPLING EQUIPMENT AND PROCEDURES .............................................. 10

5.0 INVESTIGATION DERIVED WASTE ............................................................... 11

5.1 MANAGEMENT OF HAZARDOUS IDW ...................................................... 11

6.0 REFERENCES ...................................................................................................... 12

Tables

1 Summary of Extensive List of Constituents of Interest, EPA Methods, Reporting 

Limits and Holding Times.

2 Summary of List of Constituents Based on Generator Knowledge, EPA Methods, 

Reporting Limits and Holding Times
1.0 INTRODUCTION

This Field Sampling and Analysis Plan (SAP) details the procedures for sampling and 

field documentation to be utilized for the characterization study of the fracturing and flow 

back fluids associated with the Devonian shale. The FSAP has been prepared to ensure 

that all data and information gathered are properly sampled, documented, and technically 

sound. The FSAP and Quality Assurance Project Plan (QAPP) together comprise the 

Sampling and Analysis Plan (SAP).

1.1 PURPOSE

The FSAP includes a detailed description of field sampling procedures to be conducted. 

The procedures described are consistent with the RCRA Technical Enforcement 

Guidance Document (TEGD), U.S. EPA, 1989; RCRA Facility Investigation Guidance 

Document (U.S. EPA, May 1989); RCRA Ground Water Monitoring; Draft technical 

Guidance (U.S. EPA, 1992); Data Quality Objectives for Remedial Response Activities 

(U.S. EPA, 1987).

The SAP consists of 5 sections. Section 1.0 includes a brief description of the data 

objectives and a brief discussion of the project. 2.0 provides information regarding 

documentation, quality assurance/quality control (QA/QC) requirements, and reporting. 

Section 3.0 addresses the sampling procedures. Section 4.0 describes the proper handling 

requirements of any investigative derived waste generated. Reference documents are 

provided in Section 5.0

1.2 DATA OBJECTIVES

The data objectives will address characterization of the fracturing and flow back fluids 

associated with the development of the Devonian shale. This characterization study will:

Identify the specific constituents of interest (COI) associated with flow back 

water;

Reduce/eliminate the allegations that the chemicals used for fracturing will 

contaminate groundwater; and

Provide sufficient information for the selection of proper disposal techniques.

Achieving these data objectives will require obtaining data of acceptable levels of 

certainty. Therefore, it is essential that the field and sampling procedures be completed 

under stringent and appropriate methods. 

1.3 BACKGROUND

The process of developing Devonian Shale wells requires increasing the number of 

fractures and extending the existing fractures. Fracturing is necessary to obtain a greater 

volume of natural gas from the Devonian Shale at in a cost-efficient manner. Fracturing 

uses high volumes and high-pressure chemically treated water or a gel to induce fractures 
in the shale surrounding the well bore. Most applications require between 500 and 10,000 

psi. 

Fracturing is done by isolating off a portion of the well and injecting chemically treated 

water or gel and sand with cement, perforating, under very high pressure into the isolated 

portion of the well bore. Generally, 1.5 to 5 million gallons of water is pumped into the 

formation of a vertical or horizontal well, respectively. The high pressure fractures the 

shale and sand keeps the fractures open. A drop in pressure indicates that the formation 

has accepted water. 

To prevent the fractures from closing when the pressure is reduced several hundred tons 

of sand or other propant is pumped down the well and into the pressurized portion of the 

well. When the fracturing occurs the sand is forced into the fractures. If enough sand is 

trapped in the fractures it will prop the fractures open when the pressure is reduced. The

propped fractures provide an increase in the permeability for gas flow. 

Approximately 25 to 30 percent of the water used in fracturing is recovered. This flow 

back water is currently a concern because there is a limited amount data. The ASMCWC 

is conducting this study in an effort to characterize the flow back water associated with 

the Devonian Shale. 

The flow back water will be collected in either an on-site off-stream temporary 

impoundment or a series of frac tanks.
2.0 CHARACTERIZATION STUDY OF FLOW BACK WATER

Fracturing is completed over several days depending on the geological formation. 

Because the flow back water is under pressure, initially the flowback water is recovered 

at a faster rate in the beginning of fracturing and significantly declines as facturing 

continues and the well is released to production. The initial concentrations at the start of 

fracturing (high yields of flow back water) should yield lower concentrations of 

constituents of interest (COI). It is assumed that the concentration of the fracturing

chemicals remain constant throughout the flow back regardless of the rate of return. 

However, the increase concentration of in the COI is due to a longer residence time in the 

applicable formation and not associated to the additives of the fracing fluids. 

Therefore, to obtain representative samples of the flow back water samples will be 

collected on three separate days (i.e., days 1, 5 and 14). The data obtained from day 14 

should represent the chemical characteristics of the natural formation fluid. 

Additionally, a baseline sample of the fracturing fluid will be collected prior to injection. 

The baseline sample will contain the materials (e.g., water and chemicals) used in the 

fracturing process. A sample will also be collected from a well in Devonian shale that 

has been in production for a period of time (i.e., a well that has been in production for

more than 3 months). The data obtained from this well should represent the chemical 

characteristics of the natural formation fluid. The analytical results associated with these 

samples will assist in the data interpretation.

2.1 Sampling and Analyses

In general, several frac tanks are connected in-line and filled simultaneously with the 

flow back water. This is completed to avoid back pressure when shutting one frac tank 

and opening another tank for additional capacity. This filling process will provide a 

composite sample of the flow back water over time. To minimize volatilization, a 

representative composite sample of the flow back water samples will be collected from 

the top of a frac tank or flow back impoundment. 

The flow back water is either pumped into the frac tanks for storage until the water is 

disposed of properly. If a project does have an impoundment that stores flow back water 

on site in an impoundment, a grab sample will be collected from the impoundment 

following day 1, 5 and 14 of fracturing. 

The base fracturing fluid will be collected prior to going down hole. The base fracturing 

fluid will be collected from either the sampling lines built into the blenders or as a grab 

sample from the blending containers. In either case a representative sample of the fluid 

will be collected. 

Numerous flow back water samples will be collected from several unique locations. 

Phase one of this characterization study will include the sampling of six flow back water 

samples from six unique locations. 
The list of constituents recommended for the characterization study was developed from 

comments received from the Pennsylvania Department of Environmental Protection 

(PADEP), the West Virginia Department of Environmental Protection (WVDEP) and 

members of the ASWCMC. Because the recommended list of constituents is extremely 

extensive, it was decided that one sample from each site will be completed for the full list 

of recommended constituents (Table 1). All other samples will be sampled for a subset 

of these constituents (Table 2), which are based on generator knowledge and Group 1 and 

Group 2. The analytical results of phase one of the characterization study will determine 

the list of constituents of subsequent sampling events. 
3.0 SAMPLING PROTOCOLS

This section identifies the protocols to be implemented during field sampling. 

Specifically this section describes the preparation, documentation, and reporting 

procedures to be used that will assure quality assurance and quality control.

3.1 PROJECT INITIATION

Following acceptance of this plan by the ASWCMC and the state agencies, Gas 

Technology Institute (GTI) will authorize Test America an independent a credited 

analytical laboratory to provide the appropriate sample containers and preservatives; and 

URS, an independent environmental consulting company has been retained to collect the 

flow back water. Furthermore, Test America will complete the analytical analyses. Test 

America is certified by WVDEP and PADEP.

The regulatory agencies are invited to collect split samples. The samples will be 

collected at the discretion of the agency. All agency sampling must be approved and 

coordinated with the appropriate gas company. 

3.2 DOCUMENTATION

A field logbook and chain-of-custody form will be utilized during the field activities. 

3.2.1 Field Logbook

During field activities, a site-specific logbook will be used for documentation of all notes. 

It is recommended that each page of the logbook be numbered and dated. The entries 

should be legible and contain accurate and inclusive documentation of the project 

activities. Once completed, the logbook becomes an accountable document and is 

maintained as part of the project file. The logbook should include, at a minimum, the 

following information:

Identification of logbook ownership and telephone number on the inside front 

cover;

Well location and identifying number;

Names of field personnel at the site;

Weather information (general);

Sample locations and activities;

Sample collection equipment;

Date and time of monitoring of sampling;

Water quality measurements (field pH, specific conductance, water temperature);

Field instrument calibration information;

Visual observations;

Collection of field quality assurance samples (i.e., blanks or duplicates);

Regulatory agency personnel observing sampling; 
Enter agency, collector’s name, samples splits, etc., if a regulatory agency splits 

samples; and

Documentation of sample shipment dates, time, and carrier tracking (air bill) 

number, if necessary.

Copies of the field book pages will become part of the sample data package.

3.2.2 Chain-of-Custody Form

The chain-of-custody form is used to record the custody of all samples collected. This 

chain-of-custody form documents transfer of the custody from the sampling personnel to 

another person, to the laboratory, or to another party, such as a courier delivery service. 

The chain-of-custody form also serves as a sample logging mechanism for the laboratory 

sample custodian.

When the field personnel sends samples to the analytical laboratory, each cooler chest 

containing samples must be accompanied by a chain-of-custody form. These forms 

contain the following information pertaining to the samples:

Project Name

Name(s) and signature(s) of the individual(s) collection the samples; 

Sample location;

Date and time of sample collection;

Total number of sample containers per sample location;

Type of sample preservation used (e.g., HNO3, HCl, etc.)

Analytical parameters of interest for each sample and number of containers per 

analytical parameter;

Remarks or observations;

Signature(s) of all individual(s) relinquishing and receiving custody of the 

samples;

Name of the carrier shipping the samples; and

Air bill number under which sample containers(s) was sent, if applicable;

The chain-of-custody forms are multi-colored carbon copy forms. The original copy 

(white) is submitted to the laboratory with the samples, the second copy (pink) is sent to 

GTI, and the third (yellow) is kept for the project files. 

3.3 SAMPLE DESIGNATION AND IDENTIFICATION

Each sample collected for this characterization study will be assigned a unique sample 

tracking number. The identification of the well location and participating gas company 

will not be identified. All well locations will be blind. GTI will assign each well a 

project identifier. The project identifier will be a unique single alphanumeric letter that 

will identify the Devonian Shale well location and company. This unique alphanumeric 

letter will be provided to the third party environmental consultants to be used in the 

sample designation. 
3.4 SAMPLE MANAGEMENT AND SHIPMENT

The possession of samples or other physical evidence shall be traceable from the time the 

samples are obtained until they have been submitted to the analytical laboratory. To 

simplify the documentation of possession that is maintained on the chain-of-custody 

form, the number of people who handle the sample during the investigation should be 

minimized. All samples will be documented in the field logbook, on the chain-ofcustody form and on the sample container labels. Field documentation procedures are 

provided above in Section 2.3 and the in the QAPP.

Sample labels shall be completed for each sample using waterproof non-erasable ink. All 

samples are to be sealed immediately upon collection and are to be immediately place on 

ice in a cooler.

Samples are to be properly packaged for shipment and delivery to the laboratory. To 

ensure that the samples are kept cold for preservation requirements, the samples are to be 

shipped in iced coolers for overnight delivery. Samples collected during the 

characterization study are to be classified as environmental samples.

Shipping containers are to be secured with tape and use of security seal method to ensure 

that the cooler may not be opened without evidence of the seal being tampered.

Ice used to keep the samples cooled must be secured in plastic bags (e.g., Zip-Lock® 

plastic bags) to ensure that melted ice does not cross contaminate the samples pr leak 

from the coolers. 

Samples will be either hand delivered to the laboratory or shipped via priority service to 

the laboratory or the air bill retained for the project file.
4.0 SAMPLING EQUIPMENT AND PROCEDURES

Grab samples will be conducted using a new PVC bailer from the top of the frac tank. 

The order, in which the grab samples are collected, as prioritized to the sensitivity to 

volatilization, is as follows:

Volatile Organics

Purgeable Organics

Purgeable Organic Halogens

Total Organic Halogens

Total Organic Carbon

Extractable Organics

Total Metals

Dissolved Metals

Phenols

Cyanide

Sulfate and Chloride

Turbidity

Nitrate and Ammonia

There is not an order of preference for the collection of the remaining conventional 

parameters.

Temperature, pH, dissolve oxygen, and specific conductance measurements will be 

completed in the field
5.0 INVESTIGATION DERIVED WASTE

Materials which may be investigation derived waste (IDW) are:

Personnel protective equipment (PPE), including disposable gloves, coveralls, 

booties, etc.;

Disposable equipment, including plastic ground and equipment covers, aluminum 

foil, Composite liquid waste samplers (COLIWASAs), used sample containers, 

tape, etc.;

5.1 MANAGEMENT OF HAZARDOUS IDW

If wastes are suspected to be hazardous, appropriate analysis must be performed to make 

that determination. The analytical testing should meet the requirements of the potential 

disposal characterization requirements. If the IDW is determined to be hazardous wastes 

either through testing of characteristics or as a listed waste, they must be properly 

container and labeled. They may be stored on site for a maximum of 90 days before they 

must be manifested and shipped to a permitted treatment of disposal facility. 

Care should be taken to keep non-hazardous materials segregated from hazardous wastecontaminated materials. 
6.0 REFERENCES

Kitrell, F.W. 1990. A Practical Guide to Water Quality Studies.

U.S. EPA, 1986. Test Methods for Evaluating Solid Waste, Volume II; Field Manual, 

Physical/Chemical Methods. Office of Solid Waste and Emergency Response, SW-846, 

November 1986

U.S. EPA 1987. Data Quality Objectives for Remedial response Activities. Oswer 

Directive 935507B, Office of Emergency and Remedial Response, Washington DC. 

EPA/5406/6=87/100 and 004.

U.S. EPA, 1986. RCRA Ground-Water Technical Enforcement Guidance Document. 

Office of Waste Programs Enforcement, Washington DC, Oswer Directive 99501.

U.S. EPA, 1992. RCRA Groundwater Monitoring: Draft Technical Guidance. Office of 

Solid Waste, Washington DC. EPA/530/R-93/001.

U.S. EPA, 1998. Environmental Investigations Standard Operating Procedures and 

Quality Assurance Manual. U.S. EPA Region 4, Athens, GA, May 1996. 
63

APPENDIX B: QUALITY ASSURANCE PROJECT PLAN (QAPP)
Appendix B

Quality Assurance Project Plan (QAPP)
QUALITY ASSURANCE PROJECT PLAN

DEVONIAN SHALE FLOWBACK WATER 

CHARACTERIZATION STUDY

Prepared by

Appalachian Shale Water Conservation and Management Committee

November 2008
TABLE CONTENTS

1.0 PURPOSE 3

2.0 PROJECT DESCRIPTION 4

2.1 SCOPE OF WORK 4

3.0 QUALITY ASSURANCE OBJECTIVES FOR MEASUREMENT DATA 5

3.1 DATA QUALITY LEVELS 5

3.2 QUALITY CONTROL PARAMETERS 6

4.0 SAMPLING PROCEDURES 8

4.1 SAMPLE IDENTIFICATION 8

4.2 SAMPLE CONTAINERS 9

4.3 FIELD QA/QC SAMPLES 9

4.3.1 Trip Blanks 9

4.3.2 Equipment Blanks 10

4.4 DOCUMENTATION 10

5.0 SAMPLE CUSTODY 11

6.0 ANALYTICAL PROCEDURES 12

7.0 CALIBRATION PROCEDURES AND FREQUENCY 13

7.1 PREPARATION OF STANDARDS 13

7.2 CORRECTIVE ACTION 13

8.0 DATA EVALUATION/VALIDATION 15

8.1 FIELD DATA VALIDATION 15

8.2 LABORATORY DATA VALIDATION 15

8.3 INDEPENDENT DATA VALIDATION 16

8.4 DATA REPORTING 16

8.4.1 LEVEL I REPORTING 17

8.4.2 LEVEL II REPORTING 17

8.4.3 LEVEL III REPORTING 17

9.0 QUALITY CONTROL PROCEDURES 19

9.1 FIELD QC CHECKS 19

9.1.1 EQUIPMENT BLANKS 19

9.1.2 TRIP BLANKS 19
9.2 INTERNAL LABORATORY QC CHECKS 20

9.2.2 Preparation/Method Blanks 20

9.2.3 Matrix Spike And Duplicate (Or Matrix Spike Duplicate) Analysis 21

9.2.4 Surrogate Spike Standard Performance Evaluation 21

9.2.5 Calibration Check Compounds And Reagent Blanks 21

10.0 PERFORMANCE AND SYSTEM AUDITS 22

10.1 PERFORMANCE AUDITS 22

10.1.1 Laboratory Performance Audits 22

10.2 SYSTEM AUDITS 22

10.2.1 Laboratory System Audits 22

11.0 ASSESSMENT PROCEDURES FOR DATA ACCEPTABILITY 23

11.1 PRECISION 23

11.2 ACCURACY 23

11.3 COMPLETENESS 23

11.4 QUALITY CONTROL CHARTS 24

12.0 PREVENTIVE MAINTENANCE 25

12.1 FIELD 25

12.2 LABORATORY 25

13.0 CORRECTIVE ACTION 26

14.0 QA REPORTS TO MANAGEMENT 27

FIGURE

1 Chain of Custody Record

TABLES

1 Summary of Extensive List of Constituents of Interest, Reporting Limits, and Holding 

Times

2 Summary of List of Constituents Based on Generator Knowledge, Reporting Limits, and 

Holding Times
This document is the Quality Assurance Project Plan (QAPP), which provides specific quality 

assurance/quality control (QA/QC) procedures to be executed and supported for the 

Characterization Study of the flow back water associated with the well fracturing of the 

Devonian Shale. 

Data generated for environmental purposes must be technically sound and legally defensible, and 

supported by defined and verified limits of confidence. Therefore, the objective of this QAPP is 

to ensure the generation of accurate, precise, representative and complete data. The QAPP sets 

forth the data collection procedures and data evaluation processes, which will ensure that 

appropriate levels of data quality are obtained.

Analyses must meet the QA/QC requirements associated with this QAPP and the following 

documents:

SW-846, Third Edition (September 1986), as amended by updates 1 (July 1992), II (September 

1994), IIA (August 1993), and IIB (January 1995), or the most current SW-846 update;

EPA's "Handbook for Analytical Quality Control in Water and Wastewater Laboratories" (EPA 

600/1-79-019);

Standard Methods for the Examination of Water and Wastewater. 

Only U.S. EPA-approved methods will be used for chemical analyses. Any omission in this 

QAPP of relevant requirements, tasks and other items found in the referenced methods does not 

constitute a waiver of the omitted requirement, task, or item. It is the responsibility of all 

personnel involved in the various site investigation activities to perform and document the 

required procedures designated herein.
The Appalachian Shale Water Conservation and Management Committee (ASWCMC) is 

conducting a study to characterize the fracturing and flow back water generated from 

development of Devonian Shale wells.

Samples will be collected from both vertical and horizontal Devonian Shall gas wells. Numerous 

samples will be collected from several locations. Phase one of the characterization study will 

include 4 grab samples from 6 well sites. A sample will also be collected from a well that has 

been in production for at least three months. The following grab samples will be collected from 

each site:

One baseline fracturing water sample that includes the fracturing chemicals, excluding 

the sand;

Flowback water samples will be collected on days 1, 5 and 14 of the following the

fracturing process; and 

Water from an existing producing well.

The list of constituents recommended for the characterization study was developed from 

comments received from the Pennsylvania Department of Environmental Protection (PADEP), 

the West Virginia Department of Environmental Protection (WVDEP) and members of the 

ASWCMC. Because the recommended list of constituents is extremely extensive, it was decided 

that one sample from each site will be completed for the full list of recommended constituents 

(Table 2). All other samples will be sampled for a subset of these constituents (Table 3), which 

are based on generator knowledge. The analytical results of phase one of the characterization 

study will determine the list of constituents of subsequent sampling events. 

In addition, field measurements of pH, specific conductance, temperature, dissolved oxygen, and 

turbidity will be taken of flow back aqueous samples. 
Data Quality Objectives (DQOs) are qualitative and quantitative statements to ensure that data of 

known and appropriate quality are obtained during the characterization study (sampling and 

analysis). 

The data objectives will address characterization of the flow back fluids associated with well 

fracturing generated from Devonian shale. This characterization study will:

Identify the specific constituents of interest (COI) associated with flow back water;

Reduce/eliminate the allegations that the chemicals used for fracturing will contaminate 

groundwater; and

Provide sufficient information for the selection of proper disposal techniques.

Achieving these data objectives will require obtaining data of acceptable levels of 

certainty. Therefore, it is essential that the field and sampling procedures be completed 

under stringent and appropriate methods

 

There are typically five analytical levels of data quality available to accomplish the objectives of 

investigations of this type. These levels are typically designated as follows:

Level I: field screening or analysis using portable instruments, calibrated to noncompound specific standards;

Level II: field analysis using portable instruments, calibrated to specific compounds;

Level III: non-Contract Laboratory Program (non-CLP) laboratory methods;

Level IV: CLP Routine Analytical Services (RAS) methods; and

Level V: non-standard analytical methods. 

DQO Levels I and III will be used to characterize the Devonian Shale Fracturing Flowback 

sampling activities. The following sections describe the use of the analytical procedural levels 

that will be used during the project. 

Field Screening Methods - Level I

Field determinations of pH, specific conductance, temperature, dissolved oxygen, and turbidity 
will be made during characteristic sampling as part of a field screening procedure. These 

analytical methods are used to determine stability of the well and they are typically designated as 

Level I data quality.

In addition, as part of the health and safety program, worker safety may be monitored via one or 

more of a variety of field screening tests such as a photoionization detector (PID) or flame 

ionization detector (FID) to test for volatile organic vapors, or a combustible gas indicator to test 

for explosivity potential. These tests, which are semi-quantitative, are classified as field 

screening evaluations, even though they typically are not used for site characterization purposes. 

Non-CLP Laboratory Methods - Level III

Level III analytical procedures provide precise, accurate and defensible data for the intended data 

uses, with a less formal documentation and reporting nomenclature at reduced analytical costs 

over Level IV data quality procedures. Data Quality Level III will be used during this 

characterization study. Table 1, summarizes analyses that will be conducted to characterize and 

quantify constituent concentrations.

The exact quantitative criteria used to evaluate data quality from the laboratory's precision and 

accuracy perspective for the aqueous and solid sampling media will be presented in the selected 

laboratory Quality Assurance Manual(s) (Appendix QAPP-1 and following). The following is a 

description of terms that appear in the QAM.

Reference: The reference of the U.S. EPA standard analytical methodology used for each 

procedure.

Precision: A measure of the mutual agreement among individual measurements of the same 

property under prescribed similar conditions. Precision is evaluated based on the relative percent 

difference (RPD) between duplicate matrix spike results or duplicate sample results, as 

appropriate. The matrix spike duplicate RPD limits are parameter and method-specific, 

MS/MSD RPD QC limits will be presented in the laboratory QAMs. Laboratory duplicate 

sample RPD limits are typically 20 percent for aqueous media and 35 percent for solid media 

(exceptions may apply for solid media whose samples may be nonhomogeneous). Field 

duplicates are also evaluated by calculating the RPDs between field duplicate sample results. 

However, evaluations of field duplicate RPDs are used as advisory determinations since 

numerous factors in sampling and analysis may cause variances between field duplicate results. 

Accuracy: The degree of agreement of a measurement with an accepted reference or true 

value. Accuracy is evaluated based on the percent recovery of spiked samples. The matrix spike 

recoveries for organic analyses are method and parameter specific and are typically used as an 

advisory QA/QC measure due to the difficulty associated with recovering spiked organic 
parameters. Organic parameter percent recovery QC limits will be presented in the laboratory’s 

QAM. The matrix spike recoveries for inorganic and most conventional parameters are typically 

a range of ±25 percent. 

Completeness: A measure of the amount of valid data obtained from a measurement system 

compared to the amount expected to be obtained under normal conditions. The method of 

calculation for percent completeness is defined in Section 12.3. Completeness can be evaluated 

in two ways: 1) by comparing the number of samples actually collected to the expected number 

of samples to be collected; and 2) by comparing the number of valid analyses received from the 

laboratory to the number of actual samples collected. The results of any Level III analyses to be 

performed is typically used for characterization studies and as such will have a minimum 

completeness of 95 percent for both evaluations of completeness.

Exact QA/QC criteria the laboratory will use to evaluate its data's precision and accuracy will be 

provided following selection of the analytical laboratory, if the criteria are not method-specific. 

Table 1 summarizes the individual parameters and associated reporting limits. 

There are also qualitative criteria that are adhered to ensure that data of known and appropriate 

quality are obtained during investigation activities. These criteria include representativeness and 

comparability.

The sampling and analysis programs are designed to ensure that analytical data obtained during 

the characterization study represent current conditions found at the site and produce data of 

comparable quality. The sampling frequency was selected to ensure data are suitable for their 

intended use and adequately characterize the flow back water. Additionally, standard recognized 

analytical methodologies will be utilized to ensure comparability. These designs are instituted to 

ensure appropriate sample representativeness and data comparability.
This section outlines the procedures to be used for the preparation of sampling equipment and 

containers and for sample preservation. It also provides some of the quality control and 

operating procedures to be followed for sampling. Detailed field sampling details including the 

number of samples to be collected, the rationale for sampling, and QC requirements are 

described in the Field Sampling and Analysis Plan. 

Each sample collected for this characterization study will be assigned a unique sample tracking 

number. The identification of the well location and participating gas company will not be 

identified. All well locations will be blind. GTI will assign each well a project identifier. The 

project identifier will be a unique single alphanumeric letter that will identify the Devonian Shale 

well location and company. This unique alphanumeric letter will be provided to the third party 

environmental consultants to be used in the sample designation. 

Flow back Sampling 

Fracturing is completed over several days depending on the geological formation. The flow back 

water is initially removed at a faster rate at the start of production and significantly declines as 

production continues. It is believed that the volume of water is relative to the concentration. It is 

assumed that the concentration of the fracturing chemicals remain constant throughout the flow 

back regardless of the rate of return. However, the increase of in the COI is due to a longer 

residence time in the applicable formation and not associated to the additives of the fracturing

fluids. Therefore, to obtain representative samples of the flow back water samples will be 

collected on three separate days (i.e., days 1, 5 and 14).

Additionally, a baseline sample of the fracturing fluid will be collected prior to injection. The 

baseline sample will contain the materials (e.g., water and chemicals) used in the fracturing 

process. A sample will also be collected from a well in Devonian shale that has been in 

production for a period of time (i.e., I production fro more than 3 months). The analytical results 

associated with these samples will assist in the data interpretation.

Quality Assurance

The quality assurance field will only be used to indicate a sample collected for quality assurance 

purposes. 

Quality Assurance/Quality Control Samples will be identified as follows:

EB - Equipment Blank

TB - Trip Blank
The following are sample identification samples.

A05V Sample collected from company X on day 5 from a vertical well.

CEH Sample collected from company Y from an existing horizontal well.

TB Trip Blank. 

Each sample container will be marked with a label identifying the specific parameters of interest. 

The label will record the date of sample collection, alphanumeric identification, parameters to be 

analyzed, and preservatives, if applicable. Sample bottles should be prelabeled by the laboratory 

to avoid unnecessary delays.

The specific information for each sample will be documented in the field logbook and on a 

chain-of-custody form. The sample identification will be correlated in the logbook and chain-ofcustody by sample designation, sampling date, time, and location. The analytical parameters for 

which the sample is to be analyzed and the respective number of sample bottles will be provided 

on the chain-of-custody sheet.

All new pre-cleaned sample bottles with screw-type Teflon-lined lids will be used for holding 

and shipping samples. These sample bottles will be supplied by the analytical laboratory, and 

pre-preserved by the laboratory as necessary. 

Two types of field QA/QC samples will be collected (i.e., trip blanks and equipment blanks). 

The following provides a description of the essential field QA/QC samples.

Trip blanks are collected only for volatile organic samples. The trip blank is prepared by the 

laboratory by filling a batch of pre-cleaned 40-ml vials with laboratory-grade water. The vials 

are transported to the site and returned to the laboratory in the same manner as the environmental 

sample containers. Any constituents found in the trip blank could be attributed to: a) interaction 

between the sample and the container, b) contaminated laboratory-grade water, or c) a storage or 

handling procedure which alters the sample. One trip blank should accompany VOC samples for 

each sampling event. The trip blank is placed in the cooler that contains samples for volatile 

organics. At no time after the preparation are trip blanks to be opened before they are returned to 

the laboratory.
To verify that no constituents are introduced from sampling equipment, equipment blanks are 

collected by pouring distilled water through the representative sampling device and analyzing for 

all constituents of interest. One equipment blank will be collected during the characterization 

study. 

A number of documents will be used during the characterization study. These documents 

include: chain-of-custody forms and field data sheets. 

Chain-of-custody Forms

The field chain-of-custody form is used to record the custody of all samples collected. This 

chain-of-custody form documents the transfer of the custody from the sampling personnel to 

another person, to the laboratory, or another party, such as a courier delivery service.

When the field team sends samples to an analytical laboratory, each shipping cooler containing 

samples, which are sent under one shipping document, must be accompanied by a chain-ofcustody form (Figure 1). These forms document information regarding the origination of 

samples and those parties having subsequent possession of samples. They also contain 

information pertaining to these samples, such as project name, name of the individuals collecting 

the samples, sample identification number, the date and time of collection, the number of sample 

containers for each parameter of interest for each sample, remarks or observations of samples, if 

appropriate, the signature of the person relinquishing control of the samples and the person 

receiving the samples, and the name of the overnight carrier shipping the samples to the 

laboratory. The original chain-of-custody sheet is sent with the samples. One copy will be 

submitted to Gas Technology Institute (GTI), and the other copy is stored in the field team files. 
The primary objective of sample custody is to create an accurate written verified record, which 

can be used to trace the possession and handling of the samples from the moment of collection 

through data analysis and reporting.

The field sampler will be personally responsible for the care and custody of the samples collected 

until they are properly transferred. Samples will be accompanied by a Chain-of-Custody Record. 

Upon arrival at the laboratory, samples will be checked in using laboratory custody procedures 

outlined in the laboratory QAM. The laboratory is required to verify that all samples were 

received and in good condition. The laboratory should assign a laboratory-specific sample 

identification. This unique identification guarantees sample anonymity to the analyst of the 

sample's site.

Once samples have been logged-in and transferred to the proper storage areas, the laboratory 

department manager is responsible for their proper storage and condition. Copies of the 

completed Chain-of-Custody Records and an analysis narrative presenting laboratory sample 

identifications and their correlating field assigned sample identifications should be included in 

the data package for delivery to the data user.
All analyses will be performed using U.S. EPA analytical methods procedures from the 

following:

Third Edition (September 1986), as amended by updates 1 (July 1992), II (September 

1994), IIA (August 1993), and IIB (January 1995), or the most current SW-846 update;

EPA's "Handbook for Analytical Quality Control in Water and Wastewater Laboratories" 

(EPA 600/1-79-019); 

Standard Methods for the Examination of Water and Wastewater.

Table 1 and Table 2, summarize the list the constituents of interest (COIs) associated with the 

characterization study for the flow back water from the wells of the Devonian shale and the 

required reporting limits to be reported by the laboratory. Method selection was based on the 

following factors: reliability in identification and quantifications, and comparability of sample 

results and best achievability of the lower of federal Maximum Contaminant Levels (MCLs). 

All procedures for environmental sample handling, storage, and documentation while in the 

laboratory's custody and deliverable requirements upon delivery of the data to the user are stated 

in the laboratory QAMs.
All field and laboratory equipment are calibrated before use to ensure proper operating 

conditions. Laboratory instrument calibration procedures are presented in the laboratory QAMs. 

Field calibration procedures and frequencies should be followed in accordance with the 

manufactures specifications. Field calibrations must be completed each day at a minimum. pH 

meters are required to be calibrated or verified every two hours at a minimum.

All analytical methods must be validated at some point by the use of calibration standards. A 

calibration standard is made by the appropriate dilution of a pure substance, the purity of which 

is traceable to an NBS or U.S. EPA standard. Because of the high sensitivity of many analytical 

instruments, the calibration standard is an extremely dilute version of the pure compound. 

Because of the high dilution required to be within the linear range of the instrument, the 

preparation of the calibration standard is frequently made by serial dilution rather than in a single 

step. In order to provide standard solutions at sufficiently low concentrations, a minuscule 

amount of the pure substance will be required, the measurement of which is subject to extreme 

error. Thus, it is preferable to deal with potential dilution errors, rather than with the large error 

associated with the measurement of a very small amount of the pure substance.

The initial standard is usually obtained either as a pure material or as a prepared certified solution 

of a given concentration of the pure compound or compounds. In preparing the stock solution of 

the calibration standard, great care must be exercised in measuring weights and volumes as 

accurately as possible, since all of the analyses following the calibration will be based on the 

accuracy of the calibration, and the accuracy of the analytical data is dependent on the calibration 

curve. It is the analyst's responsibility to assure that all standards used are within the standard 

solution holding time, and to prepare fresh standard solutions whenever necessary. In preparing 

working solutions, or using working solutions, the analyst must check for signs of deterioration 

of the standard, such as cloudiness, precipitation, or discoloration. The standard must also be 

periodically compared with previous runs of standards, and with independently prepared 

standards to assure that response factors fall within a historically accepted range.

There are many laboratory functions that may require corrective action. The decision to 

undertake corrective action, and the ensuing action must be documented so that traceability can 

be maintained. The point of originating the corrective action varies, depending upon the mode of 

detection that such action is necessary. It is generally the role of either the Laboratory QA 

Officer or the Laboratory Department Manager to initiate such action. Those actions that affect 

the quality of the data will be recorded and the record maintained by the Laboratory QA Officer. 
The general procedures for appropriate laboratory corrective actions and identification of 

potential problems are presented in the analytical laboratory QAM.
Data are typically validated by the laboratory and field personnel. First, during the field 

operations, field measures will be validated at the time of collection by the field sampler by 

verifying the use of standard operating procedures for the sampling effort and using field QC 

checks. Second, laboratory analytical results will be validated by the Laboratory Department 

Manager or the analyst who is the specific analytical task leader.

Validation of field obtained data, as well as ongoing QA/QC checks of environmental samples 

being taken, is performed on field data. All field data are reviewed during the time of collection 

and second, all data are reviewed by secondary field personnel if multiple personnel are present. 

Corrections in the field logbooks will be removed by placing a single line through the entry, 

initialing and dating the correction. If information is added without a correction being necessary 

that entry will be initialed and dated to indicate that it was not entered at the original time of data 

entry. Entries should never be “whited out” or made in pencil. 

The individual Laboratory Department Managers should validate all laboratory data, prior to 

reporting. Some of the following QA/QC measures are reviewed or procedures are typically 

used:

A standard curve is prepared prior to sample analysis;

The standard regression coefficient is within the acceptable range;

Standard reference materials are analyzed at the proper frequencies and acceptable results 

are obtained;

The reagent blanks are analyzed at the proper frequency;

Precision requirements of this plan are met;

Accuracy requirements of this plan are met;

Completeness requirements of this plan are met;

Samples are analyzed within the proper sample holding times;

All calculations are verified as correct;

Proper units are reported; and

The proper methodologies were used.

Besides this review of analytical results and project specific precision, accuracy, and 

completeness requirements, the Laboratory Department Manager should perform unannounced 

audits of report forms and other data sheets as well as regular reviews of instrument logs, 

performance test results, and analysts’ performance. Any review of analytical results or internal 

QA/QC checks that indicate problems, immediate corrective actions should be taken and all data 

collected since the previous approved QC audits should be reviewed for validity. Specific 
laboratory procedures for validation of the analytical data generated are described in the 

laboratory QAMs. 

The laboratory will provide DQO Level 3 (i.e., CLP Like) data packages. However, the data 

packages will not be validated at this time. Data validation procedures following the applicable 

guidance from the current U. S. EPA's Contract Laboratory Program, National Functional 

Guidelines for Organic Data Review and the U. S. EPA's Contract Laboratory Program, 

National Functional Guidelines for Inorganic Data Review will be performed, if required.

Analytical Laboratory

Once the data have been validated internally by the laboratory, all of the results are electronically 

or automatically entered into the laboratory's data management system where they are stored 

prior to reporting. When all analyses are completed for data storage, the Laboratory Director (or 

his/her designee) will issue a final data report including a descriptive case narrative. He or she 

will then issue the report to the data user. All applicable QC data should be included with the 

final report.

The data reports generated for this project should contain all pertinent information for the data 

user to determine the applicability and usability of the data for its intended purposes. For this 

reason, a specified and uniform data reporting format should be implemented. For this project, 

DQO levels III data packages will be reported as a Level IV (CLP-like) deliverable to facilitate 

data validation, if needed. The following criteria and information should be supplied, at a 

minimum, for data reports generated for this project:

1. A descriptive case narrative identifying any problems encountered during internal data 

validation (as described above);

2. Completed and legible chain-of-custodies for all analyses contained within each 

submitted data package;

3. A lab sample chronicle indicating which analyses were requested and performed for the 

samples contained in the data package;

4. A summary of the laboratory sample identifications and the correlating field sample 

identifications;

5. A summary of all applicable analytical results reported in the correct number of 

significant figures, reporting units; and
6. Included in the individual sample reporting results should be the complete sample 

identifications, the sample dilutions (if necessary), and the individual sample analysis 

dates. 

Summary reporting only will be provided. Bulleted items above are required under this DQL. 

Summary reporting only will be provided. The data package reporting requirements are the same 

as Level I except legible and calculated QA/QC summaries for laboratory blanks, surrogate 

recoveries (if applicable), laboratory control sample recoveries, and matrix spike/matrix spike 

duplicate recoveries (or matrix spike recovery and laboratory duplicate results) must also be 

supplied under this DQL. 

The following summary forms and raw data deliverable requirements will apply for Data Quality 

Level III. 

The following forms are required for all analyses using Gas Chromatography/Mass Spectroscopy 

methods.

Narrative and sample identification cross reference;

Copies of Chain-of-Custody documentation;

Laboratory chronicle;

Method summaries and references;

Organic analysis data sheet for samples and blanks (with TICs as required);

System monitoring compound/surrogate recoveries summary;

Matrix spike/Matrix spike duplicate summary or any lab duplicate;

QC Check Sample summary;

Method blank summary and results;

Instrument performance check summary;

Initial calibration summary for all constituents of interest;

Continuing calibration check summary for all constituents of interest;

Internal standard area and RT summary;

Extraction/preparation logs;

The handwritten calculation for at least one positive result in one sample at a rate of one 

calculation per twenty samples or per data package (whichever is greater) per fraction 

(e.g., VOC or SVOC); and

Raw data including run logs, mass spectra, quantitation reports and chromatograms for 
samples, as well as any raw data used to complete the hand written calculation.

The following forms are required for all total metal analyses.

Narrative and sample identification cross reference;

Copies of Chain-of-Custody documentation;

Laboratory chronicle;

Method summaries and references;

Inorganic analysis data sheets;

Initial and continuing calibration verification;

Initial and continuing calibration blanks and preparation blank summary;

ICP interference check sample summary;

Spike sample recovery;

Duplicate results summary;

Laboratory Control Sample summary;

Standard addition results summary, when applicable;

ICP serial dilutions;

Instrument detection limits;

ICP inter-element correction factors summary;

Preparation log;

Analysis run log;

The hand-written calculation for at least one positive result in one sample at a rate of one 

calculation per twenty samples or per data package (whichever is greater) per method 

(e.g., GFAA/ICP/CU); and

Raw data. 

The following data and summary forms will be submitted by the laboratory for inorganic nonmetals analyses or other analyses not discussed above:

Narrative and sample identification cross reference;

Copies of Chain-of-Custody documentation;

Laboratory chronicle;

Method summaries and references;

Analysis data sheets;

Calibration summaries; and

Calibration equation and curve plot;

Blank results summary;

Sample spike recovery, where applicable;

Duplicate sample results, where applicable; and

Laboratory control sample summary where applicable. 
Quality control (QC) procedures and checks are used to verify the accuracy of investigation data. 

Field QC checks are used to identify potential problems with sampling procedures such as the 

inconsistent use of sampling standard operating procedures or field introduced sample or water 

supply contamination and/or problems with sample homogeneity or representativeness. 

Laboratory QC checks are used to identify potential problems with analytical procedures such as 

the misapplication of required analytical methodologies or other laboratory related problems 

which could result in inaccurate or imprecise data reported. The laboratory QC checks and 

procedures presented in this section are required for most of the applicable methods, but the 

frequency of the QC checks should follow procedures outlined in the laboratory QAMs. 

To check the quality of data from field sampling efforts, field blanks and field duplicate samples 

will be collected for analysis. These samples will be treated as separate samples for 

identification, logging, and shipping. Analytical results on blanks and duplicates will be reported 

with the appropriate field sample data. The number of these samples, when required, and their 

use was described in Section 5.0.

The equipment blank provides a check on possible sources of sample contamination. The 

equipment blanks should be collected in the worst-case scenario. The reason for performing 

equipment blanks in the most impacted area is to attempt to simulate a worst-case scenario 

regarding contributions from site condition or from improperly cleaned sampling equipment to 

sample contamination. One equipment blank will be for this project. Equipment blanks should 

be handled, transported, and analyzed in the same manner as the samples with which they are 

associated. 

The equipment blank water must be maintained at 4 (±2) C following collection and during 

shipment. Holding times for individual parameters are dictated by the specific analytical method 

being used. The holding-time clock begins at the time of sample collection of the equipment 

blank.

Trip blanks are used to check for sample contamination introduced by the sample containers, by 

the sampling equipment, or by the sampling environment. Trip blanks travel to the site with the 

empty sample bottles and return from the site with the collected samples in an effort to simulate 

sample handling conditions. Trip blanks are collected in association with samples that are to be 

analyzed for volatile organic compounds. Potential sources of sample contamination are from 
the laboratory-grade reagent water, sample containers, field or laboratory ambient air, laboratory 

reagents, or cross contamination during shipping, handling, preparation or analysis. A trip blank

should accompany VOC samples for each sampling event.

The trip blank water must be maintained at 4 (±2) C through sample collection activities and 

during shipment. Holding times for individual parameters are dictated by the specific analytical 

method being used. The holding-time clock begins at the time of sample collection of the oldest 

sample in the sampling container.

The QC check frequencies and requirements specified in the following sections is a general 

description only. The laboratory will follow the internal QC checks specified in its QAM for 

each analysis type employed. However, these QC checks must meet, at a minimum, the 

requirements specified in the respective U.S. EPA analytical methods. 

The following internal laboratory QC checks are performed for most analyses, whenever 

applicable, to ensure the measurement systems are under control:

Initial and continuing calibrations;

Preparation/method blanks;

Matrix spike and matrix spike duplicate or matrix spike and laboratory duplicate analysis, 

as appropriate;

Surrogate spike standard performance evaluation (for organic analyses only); and

Calibration check compounds and reagent blanks (for organic analyses only).

Additional internal laboratory QC checks are typically performed for most analyses, as required 

by the associated analytical method. Only the most common QC checks are generally described 

below. 

9.2.1 INITIAL AND CONTINUING CALIBRATION

Each measurement system must be calibrated immediately prior to use and be shown to maintain 

the calibration throughout the course of the analysis. For the organic parameter methods, all 

target compounds will be checked during initial and continuing calibrations. Calibration 

procedures and frequencies is discussed for the various analysis types in the laboratory QAMs. 

An initial calibration will be performed prior to WSC sample analyses. Continuing calibrations 

will be typically analyzed at a minimum frequency of one every ten samples. For CLP GC/MS 

analysis, calibration checks are only required once every 12 hours of analysis. 

A preparation or method blank is run with each batch of samples received for analysis. 

Compound or analyte responses observed in the blank at levels above the reportable detection 
limit are reviewed for possible laboratory contamination. If high blank values are observed, 

laboratory glassware and reagents may need to be checked for contamination and the analysis of 

future samples halted until the system can be brought under control. A high blank value is 

typically defined as a value greater than the method detection limit. A preparation and/or method 

blank will be prepared at a frequency of one per 20 samples or one per day, whichever is greater. 

For all analyses where matrix spiking is possible, 1 in 20 samples is analyzed as matrix spikes 

and matrix spike duplicates or 1 in 20 samples is analyzed as matrix spikes and duplicates. Field 

personnel must provide additional volume for the laboratory to complete a MS/MSD. The 

percent recovery for spiked samples is calculated using the equations given in Section 12.0 and 

compared to the accuracy criteria specified in the QAM for the associated analytical method. 

The relative percent difference of replicate spikes or replicate analytical results are calculated 

using the equations given in Section 12.0 and compared to the precision criteria specified in the 

laboratory QAMs (Appendix QAPP-1 and following) for the associated analytical method. 

Surrogate standards are defined as nonpriority pollutant compounds used to monitor the percent 

recovery efficiencies of the analytical procedures on a sample-by-sample basis. Surrogate 

standard determinations are performed on all samples and blanks for organic analyses. All 

samples are fortified with surrogate spiking compounds before purging or extraction to monitor 

the preparation and analysis of samples.

Surrogate compounds and recovery levels for the associated analyses are presented in the 

laboratory QAM (surrogate recovery limits are method- and media-specific and are either 

specified in the method or are calculated annually by the analytical laboratory as described in the 

analytical method). When the surrogate recovery level is outside of the control limits on the 

initial analysis, the laboratory must take the following actions for all organic analyses for 

samples:

Check calculations to assure there are no errors, check internal standard and surrogate 

spiking solutions for degradation or contamination and check instrument performance; 

and

Recalculate or reinject/repurge the sample or re-extract and reanalyze the sample.

These calibration check compounds and reagent blanks are analyzed periodically throughout the 

course of the analysis, depending on the required analysis. The exact frequencies and methods of 

use are presented in the laboratory QAM.
Two types of audit procedures may be conducted during any environmental investigation: 

performance audits and system audits. These audits may be performed on the laboratory as well 

as field activities. A description of the laboratory's specific guidance for Performance and 

System Audits will be presented in laboratory QAMs. General procedures for laboratory 

performance and system audits are presented below. 

Laboratory performance audits are typically conducted by the Laboratory QA Officer on a regular 

basis. Each laboratory analyst is given a performance evaluation sample containing analytes for 

the parameters which he/she usually performs. These audit samples are used to identify 

problems in sample preparation or analysis techniques or methodologies which could lead to 

future analytical problems.

Additionally, the laboratory performance audits include verification of each analyst's record 

keeping, proper use and understanding of procedures, and performance documentation. 

Corrective action will be taken for any deficiencies noted during the audit.

Laboratory system audits are typically conducted by the Laboratory QA Officer. These audits are 

used to ensure that all aspects of the Laboratory's QAM are operative. This involves a thorough 

review of all laboratory methods performed and documentation to confirm that work is 

performed according to project specifications.

In some cases, outside certification agencies conduct performance and system audits to verify 

contract compliance or the laboratories' ability to meet certification requirements on methods of 

analysis and documentation. Results of these outside certification audits may be reviewed at any 

time as a check on the laboratory’s internal auditing procedures. 
The following discussion describes the procedures that will be employed to evaluate the 

precision, accuracy, and completeness of the generated data.

Precision is a measure of agreement among individual measurements of the same property under 

prescribed similar conditions. Precision is assessed by calculating the relative percent difference 

(RPD) of replicate spike samples or replicate sample analyses according to, the following 

equation:

RPD = R1 - R2 x 100 where R1 = result 1

(R1 + R2)/2 R2 = result 2

Accuracy is a measure of the closeness of an individual measurement to the true value. Accuracy 

is measured by calculating the percent recovery (%R) of known levels of spike compounds as 

follows:

 concentration of spike sample - concentration of unspiked 

sample

%R = _____________________________________________________ x 100

 concentration of spike added

Completeness is a measure of the amount of valid data obtained from a measurement system, 

expressed as a percentage of the number of valid measurements that should have been collected. 

As is specified in Section 4.2, more than one completeness check can be evaluated. It is 

calculated as follows:

number of valid samples reported

Completeness (%) = _______________________________ x 100

total number of samples analyzed
Quality control charts can be prepared after every 20 analytical determinations to graphically 

evaluate precision and accuracy criteria. The charts are prepared by calculating the mean value 

of the determinations and setting control limits at + 3 standard deviations from that mean. The 

following equations are used:

The control limits should be within acceptance limits or ranges presented in the as yet unselected 

laboratory's QAM. If the values are found to be outside these limits or ranges, the measurement 

system is examined to determine if possible problems exist. 
Periodic preventive maintenance is required for equipment whose performance can affect results. 

Instrument manuals are kept on file for reference if equipment needs repair. Troubleshooting 

sections of manuals are often useful in assisting personnel in performing maintenance tasks.

Field sampling personnel will be responsible for preventive maintenance of all field instruments. 

The field sampling personnel will protect the instruments by placing them in portable boxes 

and/or protective cases.

All field equipment will be subject to a routine maintenance program, prior to and after each use. 

The routine maintenance program for each piece of equipment will be in accordance with the 

manufacturer's operations and maintenance manual. All equipment will be cleaned and checked 

for integrity before and after each use. Necessary repairs will be performed immediately after 

any defects are observed, and before the item of equipment is used again. 

Equipment parts with a limited life (such as batteries, membranes and some electronic 

components) will be periodically checked and replaced or recharged as necessary according to 

the manufacturer's specifications.

Preventive maintenance is important since it provides for a longer useful life of the equipment 

and helps to ensure a successful field sampling and testing program. Each piece of field 

equipment will have its own log sheet which contains the equipment identification and the type 

of maintenance performed. Since most equipment is used on an irregular basis, all equipment 

will be properly stored when not in use.

All major laboratory instruments should normally be under service contract so that trained 

professionals are available on call to minimize instrument downtime. Other preventive 

maintenance schedules and/or procedures for laboratory equipment is presented in the laboratory 

QAMs (Appendix QAPP-1 and following). 
Corrective action procedures are divided into two subgroups: methods corrective action and 

systems corrective action. These corrective actions are implemented whenever system or 

performance audits note deficiencies or when QC procedures indicate a potential analytical 

problem. The laboratory guidance on Corrective Action procedures is presented in the laboratory 

QAMs. 
This QAPP provides a documentable mechanism for the assurance of quality work performed at 

for the characterization study. Audit reports will be provided by the Laboratory Director (or 

his/her designee) as a means of tracking program performance, as applicable, or if needed. 

Additionally, periodic assessments of measurement data accuracy, precision, and completeness 

and significant QA/QC problems will be performed and reported to laboratory and/or project 

management, if needed.

Field QA reports will not be necessary considering the expected size and length of any individual 

sample collection activities. Any problems noted during sampling will be immediately 

communicated to GTI, so GTI can take whatever corrective actions necessary.

Upon completion of the project-specific Work Plans, a final QA/QC report will be issued, 

assessing the overall degree of project conformance to specifications and the impact of any nonconformances that may affect management decisions. 

The final storage location of the files will be maintained at GTI’s office in Chicago. The files 

will be maintained for a period of at least three years.