# U.S. Department of the Interior **U.S. Geological Survey** 

# Scientific Investigations Report 2011–5135 

# Radium Content of Oil- and Gas-Field Produced Waters **in the Northern Appalachian Basin (USA): Summary and Discussion of Data** 

# Radium Content of Oil- and Gas-Field Produced Waters **in the Northern Appalachian Basin (USA): Summary and Discussion of Data** 

By E.L. Rowan, M.A. Engle, C.S. Kirby, and T.F. Kraemer



# Scientific Investigations Report 2011–5135

**U.S. Department of the Interior U.S. Geological Survey** 

# U.S. Department of the Interior KEN SALAZAR, Secretary

**U.S. Geological Survey** Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011

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Suggested citation: Rowan, E.L., Engle, M.A., Kirby, C.S., and Kraemer, T.F., 2011, Radium content of oil- and gas-field produced waters in the northern Appalachian Basin (USA)—Summary and discussion of data: U.S. Geological Survey Scientific Investigations Report 2011–5135, 31 p. (Available online at http://pubs.usgs.gov/sir/2011/5135/)

# iii



# Contents

Abstract

........................................................................................................................................................... 1

Introduction

..................................................................................................................................................... 1
Background

..................................................................................................................................................... 2 Data Sources and Analytical Methods

...................................................................................................... 5 New York State Department of Environmental Conservation Report (1999)

............................... 5 New York State Department of Environmental Conservation, Draft Supplemental Generic Environmental Impact Statement (2009)

.............................................................. 6 Pennsylvania Department of Environmental Protection Report (1992)

........................................ 6
Pennsylvania Department of Environmental Protection Reports (Unpublished Data, 2009–2010)

............................................................................................. 7
Dresel and Rose (2010)

......................................................................................................................... 7 This Study

............................................................................................................................................... 7

Results

............................................................................................................................................................. 8 Salinity and Radium

.............................................................................................................................. 8 Gross Alpha and Beta Particle Emissions

........................................................................................ 9

Discussion

....................................................................................................................................................... 9 Salinity and Dilution

.............................................................................................................................. 9

Radium Activities in Context

............................................................................................................. 12 Summary

........................................................................................................................................................ 15
Acknowledgments

....................................................................................................................................... 15

References Cited

.......................................................................................................................................... 15



# Figures

1. Radioactive decay chains for U-238 and Th-232

..................................................................... 3

2. Map showing locations of wells with data compiled for this study

..................................... 4

3. Differences between measurements of duplicate and replicate analyses of Ra-226 and Ra-228 in produced water samples in relation to the mean activity of the sample for data from Gilday and others (1999)

...................................................................................... 6

4. Measured activities for total radium (Ra-226 + Ra-228) and Ra-226 for each of the data sources used in the study

....................................................................................... 8

5. Gross alpha and beta particle activities in relation to the activities of Ra-226 and Ra-228, respectively

........................................................................................................... 10

6. Total radium activity, Ra-228/Ra-226, and total dissolved solids (TDS) as a function

of time since initiation of flowback

.......................................................................................... 11

7. Activities of Ra-226 and total radium (Ra-226+Ra-228) in relation to total dissolved solids (TDS)

.................................................................................................................................. 13

8. Total radium and Ra-228/Ra-226 plotted against the age of the producing formation

.. 14

# iv



# Tables

1. Well locations and related information compiled for samples used in this study

........... 19

2. Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1

.......................................................................... 26



# Units and Conversions

pCi/L – picocuries per liter

dpm – disintegrations per minute

Bq – becquerels

1 pCi = 0.037 Bq; 1 Bq = 27.03 pCi

1 pCi = 2.22 dpm; 1 dpm = 0.4505 pCi

# Abstract

Radium activity data for waters co-produced with oil and gas in New York and Pennsylvania have been compiled from publicly available sources and are presented together with new data for six wells, including one time series. When available, total dissolved solids (TDS), and gross alpha and gross beta particle activities also were compiled.

Data from the 1990s and earlier are from sandstone and limestone oil/gas reservoirs of Cambrian-Mississippian age; however, the recent data are almost exclusively from the

Middle Devonian Marcellus Shale. The Marcellus Shale represents a vast resource of natural gas the size and significance of which have only recently been recognized. Exploitation of the Marcellus involves hydraulic fracturing of the shale to release tightly held gas. Analyses of the water produced with the gas commonly show elevated levels of salinity and radium.

Similarities and differences in radium data from reser

voirs of different ages and lithologies are discussed. The range of radium activities for samples from the Marcellus Shale (less than detection to 18,000 picocuries per liter (pCi/L)) overlaps the range for non-Marcellus reservoirs (less than detection to 6,700 pCi/L), and the median values are 2,460 pCi/L and 734 pCi/L, respectively. A positive correla

tion between the logs of TDS and radium activity can be demonstrated for the entire dataset, and controlling for this TDS dependence, Marcellus shale produced water samples contain statistically more radium than non-Marcellus samples. The radium isotopic ratio, Ra-228/Ra-226, in samples from the Marcellus Shale is generally less than 0.3, distinctly lower than the median values from other reservoirs. This ratio may serve as an indicator of the provenance or reservoir source of radium in samples of uncertain origin. 

# Introduction

Radium forms naturally from the decay of uranium and thorium, elements that commonly occur in sandstones and shales in sedimentary environments. Radium has been docu

mented in the formation waters in many sedimentary basins (for example, Fisher, 1998). In the northern Appalachian Basin, radium has been measured in the water co-produced with gas and oil (that is, produced water 3 

# ) from reservoirs of Cambrian-Mississippian age. Radioactive isotopes are commonly quantified in terms of “activity concentration” or simply “activity,” which in this context refers to a number of disintegrations per unit time. For consistency with the studies cited, activity units of picocuries per liter (pCi/L) are used here to define the activity of radium in produced water samples. In surface and shallow subsurface environments, radium can be relatively soluble and, therefore, mobile in groundwater over a range of pH and Eh (redox) conditions (Langmuir and Riese, 1985; Sturchio and others, 2001). Radium also may be adsorbed onto clay particles or onto oxide grain coatings (Krishnaswami and others, 1982; Ames and others, 1983; Sturchio and others, 2001). As a radioactive element, radium may represent a potential health hazard if released into the environment. The half-lives of the two principal isotopes of radium, Ra-226 and Ra-228, are 1,600 and 5.75 years, respec

tively (Akovali, 1996; Artna-Cohen, 1997), and approximately

10 half-lives are required for a radioactive element to decay to negligible quantities. Chemically, radium behaves in a manner similar to calcium and is capable of bioaccumulation in plants and animals. There is a significant body of research aimed at quantification of radium uptake in crops and livestock that make up the human food chain (for example, Tracy and others; 1983; Bettencourt and others, 1988; Linsalata and others, 

# Radium Content of Oil- and Gas-Field Produced Waters **in the Northern Appalachian Basin (USA): Summary and Discussion of Data** 

By E.L. Rowan, 1 

# M.A. Engle, 1 

# C.S. Kirby, 2 

# and T.F. Kraemer 1

1 

# U.S. Geological Survey, Reston, Virginia.

2 

# Bucknell University, Lewisburg, Pennsylvania.

3 

# The term “produced water” in this report represents water produced from an oil or gas well at any point during its life cycle. The term, therefore, includes waters produced immediately after hydraulic fracturing, with compositions close to those of the injected fluid, as well as waters produced after months or years of production, whose compositions resemble formation water.

# 2 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

1989). Most of these studies were conducted in areas where uranium mining had previously taken place; however, it is not known whether similar investigations have been conducted in regions where oil- and gas-field produced waters are the source of radium. The purpose of this report is to compile and present data from multiple sources to facilitate ongoing

research. Activity data for radium-226 (Ra-226) and radium-228 (Ra-228) in oil- and gas-field produced waters from New York and Pennsylvania have been compiled from publicly

available sources and combined with new data for six wells (tables 1 and 2, p. 19–31). Measurements of total dissolved solids (TDS) and of gross alpha and beta activities were also tabulated when available. Unstable (radioactive) isotopes decay by emitting alpha and beta particles; therefore, alpha and beta activities can serve as rough indicators of the presence of radioactive elements. The publicly available radium data were obtained from the New York State Department of Environmental Conservation (NYSDEC), the Pennsylvania Department of Environmental Protection (PA DEP), and the Pennsylvania Geological Survey. Most of these data are available online, although the most recent Marcellus Shale produced water data were available only from the regional PA DEP offices. Three of the studies, Gilday and others (1999), Pennsylvania Department of Environmental Protection (1992), and Dresel and Rose (2010), provide data from wells producing from reservoirs of Cambrian-Devonian age. In contrast, the analyses reported by the New York State Department of Environmental Conservation (2009) and by the Pennsylvania Department of Environmental Protection (unpub. data, 2009–2010) are for produced waters predominantly from the Devonian Marcellus

Shale.



# Background

The Appalachian Basin comprises a vast accumulation of sedimentary rock west of the Appalachian Mountains, extending from Quebec and Ontario south through New York, Pennsylvania, Ohio, West Virginia, to Alabama. Hydrocarbons are produced throughout the basin from reservoirs of Cam

brian-Pennsylvanian age (Legall and others, 1981; Milici and others, 2003). In recent years, however, the Middle Devonian Marcellus Shale has become the focus of gas exploration and production, particularly in Pennsylvania, New York, and West Virginia. A regional comparison of produced water salinities indicates that Appalachian Basin salinities are high relative to other oil- and gas-producing basins in the United States (Breit, 2002). The compilation yielded a median TDS of about 250,000 milligrams per liter (mg/L) for the Appalachian Basin (USA), which was exceeded only by the median salinity for the Michigan Basin (about 300,000 mg/L). The data presented here indicate a wide salinity range for water produced from the Marcellus Shale, from less than 1,500 mg/L to greater than 300,000 mg/L. The lower salinities may be attributed in part to dilution with less saline fluid injected during hydraulic fractur

ing, but the upper end of the salinity range is comparable to the waters produced from the underlying Lower Devonian and older reservoirs as well as some of the overlying Devonian reservoirs (Rowan and others, 2010). The Marcellus Shale is an organic-rich shale that is both the source rock and the reservoir for an extensive natural gas resource (Harper, 2008). Shale-gas accumulations, such as the Marcellus, are termed “unconventional” or “continuous” because the gas is dispersed within a stratigraphic interval rather than confined by a conventional structural or strati

graphic trap. The process of “hydraulic fracturing” commonly is used to access the gas in a continuous reservoir. In this process, water is pumped into a well at pressures high enough to fracture the rock, and the newly created fracture network allows gas that is tightly held in micropores or adsorbed onto clay particles to be released. The injected fluid may be freshwater or relatively dilute, or alternatively, it may have been recycled, that is, produced from one well and then used to hydraulically fracture a new well. The water flowing from hydraulically fractured wells initially reflects the composition of the injected fluid, but with time shifts toward salinities and inorganic chemical compositions similar to the fluids in adjacent formations (for example, Rowan and others, 2010). Hayes (2009), for example, examined the chemistry of produced water samples collected from 12 Marcellus Shale wells at 1-, 5-, 14-, and 90-day intervals following hydraulic fracturing. The water injected into these wells was essentially fresh, with a median TDS of less than 1,000 mg/L, but within 90 days, the salinities had increased to a median value exceed

ing 200,000 mg/L TDS. Ra-226 and Ra-228 are the decay products of U-238 and Th-232, respectively (fig. 1; Ivanovich, 1992). Once formed, radium may remain within the original host mineral or other solid phase, or may be released into the adjacent pore water. Lithologies that contain substantial amounts of uranium and (or) thorium can, therefore, have measurable amounts of radium dissolved in their pore waters. The data compiled in this report span most of the oil- and gas-producing regions of the Appalachian Basin in Pennsylvania and New York (fig. 2), and show significant levels of radium in produced water samples from Cambrian-Mississippian reservoirs. Dissolved radium occurs predominantly as the Ra +2 

# ion, but also forms complexes with chloride, sulfate, and carbonate ions (Rose and Korner, 1979; Kraemer and Reid, 1984; Langmuir and Riese, 1985; Sturchio and others, 2001). Aqueous radium may remain in solution, be adsorbed from pore water onto oxide grain coatings or clay particles by ion exchange, or may substitute for cations, such as Ba +2 

# , Ca +2



# , and Sr +2 

# , during precipitation of mineral phases, such as barite, anhydrite, and calcite. Radium sulfate (RaSO
4 

# ) is much less soluble than barite, anhydrite, and other sulfate minerals, but rarely occurs as a separate mineral phase. When alkali earth sulfates precipitate, however, radium present in solution

# Background **3**

**Figure 1.** Radioactive decay chains for ( A ) U-238 and ( B ) Th-232. Times shown are half-lives: y, years; d, days; h, hours; m, minutes; s, seconds. Ra-226 and Ra-228 (shaded) are the primary isotopes of interest in this study. Half-lives were obtained from the National Nuclear Data Center ( http://www.nndc.bnl.gov/chart/ ). U-238 U-234
2.5 x 10 5 

# y

Th-230
7.5 x10 4 

# y

Po-214
1.6x10 -4 

# s Ra-226 1600 y

Rn-222
3.8 d

Po-218
3.1 m

Bi-214
19.9 m

Pb-214
26.8 m Pb-210 22.2 y Pb-206 (stable) Po-210
138.4 d

Bi-210
5.0 d Th-234
24.1 d Pa-234
6.7 h

Th-232
1.4 x 10 10 

# y

Po-212

3.0 x10 -7 

# s Th-228 1.9 y

Ra-224
3.6 d Ac-228
6.15 h

Rn-220
55.6 s

Po-216

Bi-212
60.6 m

TI-208
3.05 m Pb-212
10.6 h Pb-208 (stable) Ra-228 5.75 y 

# Uranium

Protactinium

Thorium

Radium

Radon

Polonium

Bismuth

Lead

Thorium

Actinium

Radium

Radon

Polonium

Bismuth

Lead

Thallium 

# A **. Uranium-238**

**EXPLAN A**  **TION**

Alpha decay

Beta decay



# EXPLAN **A TION** 

Alpha decay

Beta decay 

# B

**. Thorium-232**

Figure 1 0.145 s 4.5 x 10 9 

# y

# 4 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Figure 2.** Locations of wells with data compiled for this study.ElkErieLewisTiogaYorkErieOneidaPotterSteubenCentreHerkimerBerksOtsegoJeffersonDelawareBradfordPikeLycomingClintonButlerOswegoBedfordClearfieldAlleganyWarrenMcKeanLuzerneCrawfordIndianaSomersetBlairCattaraugusWayneFayettePerryCayugaTiogaBucksLancasterFranklinChesterOntarioBroome

ChautauquaMercerChenangoWayneMonroeClarionCambriaSchuylkillOnondagaVenangoMadisonMonroeGreeneHuntingdonAdamsAlleghenyYatesFultonWashingtonCecilWestmorelandForestJeffersonNiagaraWyomingArmstrongSusquehannaBeaverCortlandSullivanGeneseeHarfordSalemUnionCarbonTompkinsOrleansSnyderCumberlandChemungWyomingLebanonSchuylerDauphinLivingstonMifflin 

# HamiltonColumbiaSenecaJuniataLehighCameronNew Castle 

# MontgomeryLackawannaLawrenceGloucester

Northumberland NorthamptonDelaware



# MontourPhiladelphiaHarfordSullivanMARYLANDPENNSYLVANIAPENNSYLVANIAPENNSYLVANIA

PENNSYLVANIA 

# PENNSYLVANIANEW YORK

OHIOWEST VIRGINIA 

# NEW JERSEYPA DEP (1992)NYSDEC (Gilday and others, 1999)NYSDEC (2009)PA DEP (unpub. data, 2009–2010)Base from U.S. Geological Survey digital data**EXPLANATION**Dresel and Rose (2010)This study80°78°76°40°42°44°0507510025MILES08012040KILOMETERSPennsylvaniaNewYorkNew JerseyMap AreaWestVirginiaLAKE ONTARIOLAKE ERIE

# Data Sources and Analytical Methods **5**

coprecipitates as a solid-solution, preferentially enriching the solid phase and depleting the solution of radium (Langmuir and Riese, 1985).



# Data Sources and Analytical Methods

The sources of data in this report (tables 1 and 2) are discussed below together with the available information on quality assurance/quality control (QA/QC), analytical methods, and uncertainty. The U.S. Environmental Protection Agency (USEPA) method codes refer to standard analytical procedures defined by the USEPA (Krieger and Whittaker, 1980; Eaton and others, 2005).



# New York State Department of Environmental Conservation Report (Gilday and others, 1999)

The New York State Department of Environmental Conservation (NYSDEC) conducted a study titled “An Investigation of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas Wells in New York State,” in which produced water, oil, sludge, and other waste materials were sampled from oil and gas wells in New York State (Gilday and others, 1999). Analyses were reported for a total of

57 brine samples collected from 48 oil or gas well sites, with

9 duplicate or replicate samples (table 1). The NYSDEC report indicates that the brines were sampled from storage tanks, but the length of time between production and sample collection is unknown. The wells in this study produced hydrocarbons and water from formations of Cambrian through Lower Devonian age, with one sample of possible mixed Lower Silurian and Upper Devonian reservoir origin (table 1). Several of the wells produced from the Lower Devonian Oriskany Sandstone and Helderberg Limestone. Silurian reservoirs provided samples from the Akron Sandstone, Bass Islands Dolomite, Medina Sandstone, and Rochester Shale. Ordovician reservoirs included sandstones within the Queenston Shale. Analyses of radium activity in the NYSDEC report were determined using gamma-spectrometry as well as alpha-spectrometry in some cases. Gamma-spectrometry compares the gamma-ray wavelengths emitted by radioactive material with the emission spectra of known radioactive elements. In some instances, the signal emitted by a daughter product can be more accurately identified and quantified than that of its parent isotope. Laboratories may therefore elect to report a daughter product activity as representative of its radium parent’s activity in an appropriately prepared sample. Gilday and others (1999) considered that the Ra-226 daughter products Pb-214 and Bi-214 were the most reliable indicators of Ra-226 activity, and they selected the larger of the Pb-214 and Bi-214 values to represent the Ra-226 activity. Gilday and others (1999) considered Ac-228 activity to be the most reliable indicator of Ra-228 activity, and Pb-212, which occurs lower on the decay chain (fig. 1), was seldom used.

The values listed in table 2 are consistent with the approach of Gilday and others (1999), but several instances differ from the values highlighted in their report as representa

tive of a given sample. At one well (no. 76), the Pb-212 activity was anomalously high, 23,900 pCi/L, relative to a corresponding Ac-228 activity of 1,500 pCi/L. Gilday and others (1999) concluded that the Pb-212 value was erroneous, although this was the value they highlighted as representative of the sample. At a second well (no. 82), a Pb-212 activity of 7,650 pCi/L also appeared to be anomalously high relative to the Ac-228 activity of 1,110 pCi/L. In both instances, the Ac-228 rather than the Pb-212 activities are used to represent Ra-228 in table 2. Pb-212 activities were used in only five instances where Ac-228 was not reported. In wells where duplicate analyses were available, (nos. 38, 56, 79, and 80), the averages are given in table 2. All of the samples collected by Gilday and others (1999) were analyzed by an outside contract laboratory, and a subset of nine samples was also analyzed by the NYSDEC Bureau of Pesticide and Radiation laboratory. Some interlaboratory comparison and QA/QC information was provided in that report and is discussed below. Ideally, metrics of both analyti

cal accuracy (proximity of measured value to the “true” value) and precision (measurement reproducibility) are presented. Because no analyses of reference materials or other standards were reported, the analytical accuracy for the included data is unknown. Sample precision was examined by comparing data for analyses of duplicate 4 

# and replicate 5 

# samples (fig. 3). Despite the reported “internally consistent results” from each laboratory, the measurement uncertainty ranges did not overlap in five out of nine brine samples analyzed by both

laboratories. A single outlier exhibited an exceptionally high

difference of 143 percent between replicate analyses for

Ra-226. These findings indicate that sample precision is generally better (less than 20 percent discrepancy between duplicate or replicate samples) for samples that contained greater than 500 pCi/L, but poor agreement in interlaboratory comparisons indicates there may be bias between data sources. The magnitude of the biases, however, appears to be in the tens of percents while radium activities in brine samples range over more than four orders of magnitude. This comparison suggests that even the higher end of analytical imprecision observed in the data does not significantly affect the magnitude of radium activities reported.

4 

# Duplicate refers to individual samples from a single source collected at the same place and time.

5 

# Replicate refers to a repeat analysis made on the same sample or aliquots of the same sample.

# 6 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**



# New York State Department of Environmental Conservation, Draft Supplemental Generic Environmental Impact Statement (2009)

In 2009, the NYSDEC released a study titled “Draft Supplemental Generic Environmental Impact Statement related to Marcellus Shale Gas Development” (New York State Department of Environmental Conservation, 2009). Appendix 13 of the document, “NYS Marcellus Radiological Data from Production Brine,” lists gross alpha

, gross beta

, and activities of Ra-226 and Ra-228 for water samples collected

from 12 gas-producing Marcellus Shale wells in New York State. Appendix data were presented in table form without accompanying text, information relating to QA/QC, or analyti

cal methods. However, well lease names and API numbers, towns, and counties were provided, allowing well locations

and related information to be obtained from the State database ( http://www.dec.ny.gov/ ; fig. 2; tables 1 and 2). Activities of uranium, thorium, and the anthropogenic isotopes, cesium-137, cobalt-60, ruthenium-106, and zirconium-95, were listed in the appendix, but are not compiled in this report. 

# Pennsylvania Department of Environmental Protection Report (1992)

In 1991, the PA DEP conducted field work for a study of salinity and radium activities in produced waters, sludge, and other related waste from oil and gas wells in Pennsylvania. The results were compiled in a report titled “NORM Survey Summary” and released the following year (Pennsylvania Department of Environmental Protection, 1992). The wells sampled for the study produced hydrocarbons and water from Lower Silurian–Upper Devonian Formations, with one sample thought to be from an Ordovician reservoir. Although the Marcellus Shale falls within this stratigraphic interval, the study long pre-dated the recent (2005–present) focus on the Marcellus Shale as an unconventional gas resource. Among the most commonly sampled reservoirs were sandstone in the Silurian Medina Group, the Lower Devonian Oriskany Sand

stone, Huntersville Chert, and Onondaga Limestone, as well as Upper Devonian sandstones (table 1). About three-fourths of the samples were taken from storage tanks, or separator tanks, and the remaining samples were collected from surface pits or diked areas (table 1). The length of time between hydrocarbon production and sample collection is unknown, and therefore, Ra-228 activity may have been markedly reduced by natural decay. Brines that accumulated in open pits presumably would have been subject to evaporation and (or) dilution by rain. **Figure 3.** Differences between measurements of duplicate and replicate analyses of Ra-226 and Ra-228 in produced water samples in relation to the mean activity of the sample for data from Gilday and others (1999). The solid lines represent 10 percent and 20 percent relative difference between duplicates/replicates using the method of Thompson and Howarth (1978). Samples with higher radium activities generally have better measurement precision, that is, lower percentage differences.Absolute measurement difference,in picocuries per liter



# Mean activity, in picocuries per liter 600

0 400

200

0 500 1,000 1,500 2,000 

# >20%

10

– 20%

<10%



# Figure 3 Ra-226 

# EXPLANATION

Ra-228

# Data Sources and Analytical Methods **7**

In addition to brine samples, samples of sludge, drill cuttings, and pipe scale from brine treatment facilities, pipe yards, disposal wells, and other facilities were analyzed, but these results were not compiled in this report. No information on the laboratory, analytical methods, uncertainties, or QA/QC was included with the PA DEP (1992) report.



# Pennsylvania Department of Environmental Protection Reports (Unpublished Data, 2009–2010)

A number of the annually filed “Form 26R” (Chemical Analysis of Residual Waste, Annual Report by Generator) waste reports related to shale gas production were obtained from the PA DEP. The forms and accompanying chemical analyses are filed annually with the PA DEP by generators of liquid or solid waste, including oil and gas well operators. The 26R forms can be viewed at the DEP regional offices by appointment, or photocopies can be requested from the DEP. The DEP offices in Williamsport and Pittsburgh were visited during the spring and summer of 2010, and the

available 26R forms pertaining to liquid waste generated at gas well sites were electronically scanned. Additional data were obtained by correspondence with the Meadville, Pa.,

office. Radium activities from the 26R forms were included in this report only when the well name and related information could be obtained for a given sample. Information obtained from 26R forms filed with the PA DEP during 2009–2010 for a total of 23 wells was compiled and included in tables 1

and 2. In most instances, the TDS values of the samples were

also available. Time series data were available for four wells (table 2). When duplicate analyses were provided, the average

value is shown in table 2. Laboratory notes accompanying 26R forms reported to the PA DEP varied substantially between individual wells, but all included the laboratory name and, in some cases, the analytical method and QA/QC information. Despite the numerous different reporting entities, the radiochemical data reported in the 26R forms were obtained from only four different laboratories, and all are accredited in accordance with the National Environmental Laboratory Accreditation Program (NELAP). Gross alpha and beta emission measurements included in the PA DEP 26R forms were determined by methods that

include standard and modified versions of EPA Method 900.0 (Gross Alpha and Gross Beta Radioactivity in Drinking Water) and Standard Method 7110C (Eaton and others, 2005). No duplicate samples, replicate analyses, or other QA/QC information were available for either the gross alpha or beta

results. When methods for radium analysis were reported, Ra-226 activity typically was measured using gamma-spectrometry, and in some cases by alpha-spectrometry, using standard USEPA methods: EPA Method 901.1 (Gamma Emitting Radionuclides in Drinking Water), EPA Method 903.0 (Alpha-Emitting Radium Isotopes in Drinking Water), and EPA Method 903.1 (Radium-226 in Drinking Water Radon Emanation Technique). Radium-228 was analyzed using similar methods: EPA Method 901.1 (Gamma Emitting Radionuclides in Drinking Water) and EPA Method 904.0 (Radium-228 in Drinking Water). For the four sets of duplicate Ra-226 and Ra-228 analyses, the discrepancies were less than 7 percent, with one exception: Ra-226 analyses in duplicate samples from well no. 1 differed by 72 percent.



# Dresel and Rose (2010)

A recent publication by Dresel and Rose (2010) reports the produced water analyses originally conducted as part of a Master’s thesis at Pennsylvania State University (Dresel, 1985). Of the 40 samples collected, Ra-226 analyses are reported for six wells producing hydrocarbons and water from Lower Silurian–Upper Devonian sandstone reservoirs; Ra-228 values are not reported. Most of the samples in this study were collected from the wellhead rather than secondary storage units (table 1). The Ra-226 activities reported were determined by measurement of radon-222 activity at secular equilibrium (Rose and Korner, 1979), using a method equivalent to USEPA Method 903.1 (Krieger and Whittaker, 1980). Detailed QA/QC

information was not available.



# This Study

Radium activities have been determined at the U.S. Geo

logical Survey (USGS) for samples from six additional Marcellus Shale gas wells in Pennsylvania. Samples were collected from five of the wells (nos. 127–131, tables 1 and 2) as part of a study by Pritz (2010). The precise localities of these wells in Bradford County are confidential, and they are represented in figure 2 by a single point. Well no. 132 was sampled jointly by the USGS, the Department of Energy, and industry collaborators on successive dates, thus providing time series information. Analyses of the samples were conducted at the USGS radiochemistry laboratory in Reston, Virginia. Two to four duplicates of each sample from well no. 132 were prepared and analyzed, and the average values are reported in

table 2. In the samples from well no. 132, radium was chemically separated from the water by coprecipitating it with barium sulfate. The precipitate was then placed in the well of a high purity germanium detector, and quantitative analysis of the Ra-226 and Ra-228 content of the precipitate was performed by gamma-spectrometry using a technique adapted from Moore (1984). As discussed above for the New York State data of Gilday and others (1999), Ra-228 was quantified by measuring the intensity of gamma rays emitted by Ac-228, and Ra-226 was quantified by measuring the intensity of the gamma rays emitted by Pb-214 and Bi-214. As described in Kraemer (2005), the gamma-ray spectrometry systems were calibrated using standardized radium isotopic solutions.

# 8 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

Uncertainties for these analyses are listed in table 2 as +/– one standard deviation from the mean peak intensity and represent the “counting error” for a specific analysis. When duplicate samples were prepared, that is, reprecipitated, and analyzed, the range of the discrepancies matched closely with the range for the counting error: 0.2–8.5 percent. However, the discrepancies between analyses of duplicate samples were most commonly 2–4 percent higher than the counting error. In all cases, the maximum error did not exceed +/– 8.5 percent.



# Results

**Salinity and Radium**

Salinities, reported as TDS, were available for approxi

mately one-half of the produced water samples and ranged from 1,470 to 402,000 mg/L with a median of 157,000 mg/L TDS (table 2). The median total radium (defined here as Ra-226 + Ra-228) activity for the non-Marcellus Shale pro

duced water samples is 1,011 pCi/L compared with 2,460 for Marcellus Shale produced water samples and 5,490 pCi/L for the Marcellus produced water data for New York State (fig. 4; New York State Department of Environmental Conservation, 2009; Pennsylvania Department of Environmental Protection, unpub. data, 2009–2010; this study). For comparison, the total radium limit for industrial effluent is 60 pCi/L, and the drinking water limit is 5 pCi/L (U.S. Environmental Protection Agency, 1976; Hess and others, 1985; U.S. Nuclear Regula

tory Commission, 2011). In the NYSDEC (2009) study, salinities were not reported; however, two wells, no. 28 and no. 33, were resampled and analyzed by Osborn and McIntosh (2010), yielding respective salinities of 206,446 and 205,102 mg/L TDS. Samples at two additional wells, no. 24 and no. 25, both from depths of approximately 2,600 feet (ft), exhibited very low total radium activities (less than 1 pCi/L), although the activities of the remaining sites exceeded 1,900 pCi/L (fig. 4; table 2). The reason for the low radium content of these samples is unknown, but they may have been composed largely of water injected for hydraulic fracturing, which often is of lower salinity and radium content than the formation

water. In Pennsylvania, the range of total radium activities for the Marcellus Shale samples (Pennsylvania Department

**Figure 4.** Measured activities for total radium (Ra-226 + Ra-228) and Ra-226 for each of the data sources used in the study. The three datasets for produced water from Marcellus Shale wells are shown on the left; the remaining three datasets are for non-Marcellus Shale wells. The number of points in each dataset is shown in parentheses, and the median values are plotted as heavy black lines. For reference, the dashed line shows the industrial effluent discharge limit (60 pCi/L) for Ra-226 (U.S. Nuclear Regulatory Commission, http://www.nrc.gov/reading-rm/ doc-collections/cfr/part020/appb/Radium-226.html ).



# F i g u r e 4 0 1 1 0 1 0 0 1

, 0 0 0 1 0

, 0 0 0 1 0 0

, 0 0 0 Ra-226 Ra (total) Ra (total) Ra (total) Ra-226 Ra (total) Ra-226 Ra (total) Ra-226



# PA DEP (2009

– 2010,

unpub. data) (25) this study (14) NYSDEC (2009) (13) NYSDEC (Gilday and others, 1999) (48) PA DEP (1992) (37) Dresel and Rose (2010)

(6)Ra (total), Ra-226, in picocuries per liter 

# Ra-226



# Marcellus Shale data Ra-226

# Discussion **9**

of Environmental Protection, unpub. data, 2009–2010) is

similar to the Marcellus data from New York but is more evenly distributed (less clustered) over the range. Dilution of formation water with the relatively freshwater from the hydraulic fracturing process may have been an important factor influencing the distribution of both salinity and radium content. The time interval between hydraulic fracturing and sample collection is known in only a few cases.



# Gross Alpha and Beta Particle Emissions

Emission of alpha and beta particles accompanies the decay of Ra-226 and Ra-228, respectively (fig. 1), and the USEPA has established the measurement of gross alpha and beta as a method of screening samples for the presence of radium (Hess and others, 1985; Buckwalter and Moore, 2007, p. 48). Gross alpha and beta data were available for two datasets (New York State Department of Environmental Conservation, 2009; Pennsylvania Department of Environ

mental Protection, unpub. data, 2009–2010) and are plotted with Ra-226 and Ra-228, respectively (figs. 5 A

– B ). On log-log scales, gross alpha and gross beta activities are linearly correlated with Ra-226 and Ra-228, confirming their value as indicators of radium activity. Although these isotopes are unlikely to be the only sources of alpha and beta particles, the correlations shown in figures 5 A

– B suggest that they are likely to be the dominant sources for these samples.



# Discussion

**Salinity and Dilution**

Several studies of Appalachian Basin formation water chemistry have shown general trends of increasing salinity with depth and age of the reservoir (for example, Stout and others, 1932; Poth, 1962; Breen and others, 1985); however, high salinities can occur even at relatively shallow depths. A salinity-depth curve for Mississippian-Devonian formation waters in eastern Ohio showed greater than 100,000 mg/L TDS at 1,000 ft (Stout and others, 1932, p. 18). Poth (1962, p. 37–38, table 6) noted that on the basis of a limited set of samples, an equilibrium salinity had apparently been reached in Middle Devonian and older reservoirs, and water produced

from these units have a dissolved solids content of about 300,000 mg/L. In the dataset compiled here, produced water

salinities from the Middle Devonian Marcellus Shale com

monly range from 100,000 to 200,000 mg/L TDS (table 2). Despite the presence of evaporites in the Silurian Salina Group in parts of New York and Pennsylvania, many authors consider that the salinity of the produced waters in much of the Appalachian Basin originated from the evaporative con

centration of seawater (for example, Stout and others, 1932; Sanders, 1991; Dresel and Rose, 2010; Osborn and McIntosh, 2010). Brines derived from seawater evaporation are enriched in bromide and can be distinguished from brines formed by dissolution of evaporites on the basis of relations among Na, Cl, and Br (Walter and others, 1990). Brines produced with gas from Marcellus Shale wells after salinities have reached a plateau share similar major ion chemistries with formation waters from the overlying and underlying Devonian formations and show similar Na-Cl-Br relations (Osborn and McIntosh, 2010; Rowan and others, 2010). On the basis of these chemical similarities, a similar origin for the salinity of waters produced from the Marcellus Shale and from adjacent overlying and underlying formations can be hypothesized. Blauch and others (2009), however, reported small lenses

of halite and other salts in core from the Marcellus Shale and suggested that dissolution of these minerals contributed to the salinity of the produced waters. They also described minor volumes of salts, but noted that similar occurrences have not previously been reported in the literature on the Marcellus. Where present, salt lenses would contribute to total salinity, but it is difficult to assess their distribution or quantify their contribution to total fluid salinity. The elevated bromide concentrations and Na-Cl-Br relations suggest that the dominant source of salinity for Marcellus Shale waters, and for other formations in the stratigraphic section, originated as evaporatively concentrated seawater. Dilution of formation water with relatively freshwater injected during the hydraulic fracturing may account for some of the lower salinity values. For example, in well no. 11 salini

ties were measured 14 and 90 days after hydraulic fracturing and showed an increase with time (fig. 6 A ; table 2). In well no. 5, successive salinity measurements made 17 days apart also showed increased salinity with time (table 2). In a more detailed study by Hayes (2009), repeated measurements of produced water salinity up to 90 days after hydraulic fractur

ing showed increases in salinity with time from less than 1,000 mg/L to greater than 100,000 mg/L TDS. The marked increase in salinity with time is interpreted to represent a decreasing proportion of the lower salinity injected fluid and an increas

ing proportion of the saline formation water returning to the surface. As mentioned previously, dissolution of mineral phases such as halite, if present, could also contribute salinity. For data compiled from the PA DEP 26R forms, when the sample collection date occurred less than 90 days from the initiation date of drilling, it seems plausible that salinities less than 100,000 ppm TDS may have been affected by dilution of the formation water with the water injected during hydraulic fracturing. Like salinity, radium in the produced waters increases with time following hydraulic fracturing. A well producing gas from the Marcellus Shale in Greene County, Pa. (no. 132), was sampled daily for the first 5 days, then on days 7, 15, and 20 following hydraulic fracturing. The radium data for these samples are discussed below, but the salinity data are not yet available. The hydraulic-fracturing supply water was a mix of water recycled from similar gas wells nearby and more dilute surface water. Following hydraulic fracturing, the total radium activity in the produced water increased sharply

# 10 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

**Figure 5.** ( A ) Log of gross alpha particle activity in relation to the log of Ra-226 activity and ( B ) log of gross beta particle activity in relation to the log of Ra-228 activity. Gross beta activities below the reported detection limit in well nos. 17 and 33 are not plotted or used in the best fit line. y = 1.35x – 2.05
R 2 

# = 0.78

–1.0

0.0 1.0 2.0 3.0 4.0 5.0

0.0 1.0 2.0 3.0 4.0 5.0 

# Log gross alpha, in picocuries per literLog Ra-226, in picocuries per literRa-226, inpicocuries per liter



# 0.1 1 10 100 1,000 10,000 100,000 1 10 100 1,000 10,000 100,000



# Figure 5. **B A**  Gross alpha, in picocuries per liter

y = 1.34x – 2.14
R 2 

# = 0.54

–2.0 –1.0

0.0 1.0 2.0 3.0 4.0

0.0 1.0 2.0 3.0 4.0 5.0 

# Log gross beta, in picocuries per liter

Gross beta, in picocuries per literLog Ra-228,picocuries per literRa-228, inpicocuries per liter



# 0.01 0.1 1 10 100 1,000 10,000 1 10 100 1,000 10,000 100,000

# Discussion **11**

**Figure 6.** ( A ) Total radium activity and total dissolved solids related to time since initiation of flowback for well no. 11, Washington County, Pa. ( B ) Total radium activity (left axis, squares) and Ra-228/Ra-226 (right axis, diamonds) related to time since initiation of flowback for well no. 132, Greene County, Pa. 

# EXPLANATION

T o t a l r a d i u m

R a

- 2 2 8 / R a

- 2 2 6 T o t a l r a d i u m 

# EXPLANATION

T otal dissolved solids

0 1

, 0 0 0 2

, 0 0 0 3

, 0 0 0 4

, 0 0 0 5

, 0 0 0 6

, 0 0 0 7

, 0 0 0

0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9



# D a y s since initiation of flowbackTotalradium, in picocuries per liter



# 0

. 1 0 0

. 1 5 0

. 2 0 0

. 2 5 0

. 3 0 0

. 3 5 0

. 4 0Ra-228/Ra-226, in picocuries per liter 

# 0 5 0 0 1

, 0 0 0 1

, 5 0 0 2

, 0 0 0 2

, 5 0 0 3

, 0 0 0 3

, 5 0 0 4

, 0 0 0

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0



# D a y s since initiation of flowbackTotalradium, in picocuries per liter



# 0 5 0

, 0 0 0 1 0 0

, 0 0 0 1 5 0

, 0 0 0 2 0 0

, 0 0 0Total dissolved solids, in milligrams per liter



# 20 

# B **A**

# 12 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

during the first week from the activity of the supply water (about 1,600 pCi/L) to a plateau at about 6,100 pCi/L (fig. 6 B ). The increase in radium activity is interpreted as the result of equilibration between the injected water, whose radium activity is relatively low, and the radium that is present in the reservoir, either adsorbed onto mineral surfaces or dissolved in pore water. An anomalously low value on day 7 remains as yet unexplained; close agreement between multiple repeat analyses of the original sample conducted on different dates rules out an instrumental or analytical error as an explanation.

The Ra-228/Ra-226 ratio for this fluid decreased from the initial value of 0.23 in the injected water to 0.12. Following an unexplained increase on day 7, the ratio returned to about 0.16. Low isotopic ratios reflect the low Th/U ratio that generally characterizes the Marcellus Shale. The evolution of total radium and Ra-228/Ra-226 with time displays a fairly consistent pattern, with the exception of day 7. The area being drained by the well on this day may have intersected a “pocket” of chemically distinct water, possibly a sandy horizon in the shale or a fracture intersecting a distinct facies.



# Radium Activities in Context

In a study of NORM (naturally occurring radioactive material) in oil- and gas-producing regions, Fisher (1998) compiled radium activity data for nine sedimentary basins in the United States and Europe. In separate studies, Ra-226 activities were reported for formation water samples from clastic aquifers in the U.S. Gulf Coast (Kraemer and Reid, 1984) and from carbonate aquifers in the U.S. midcontinent (Sturchio and others, 2001). Radium activity ranges for these regions generally are comparable to those compiled here for the Appalachian Basin. The highest reported values found in literature are from the Donieper-Donets Basin, Ukraine (Gutsalo, 1964, cited in Kraemer and Reid, 1984) and from the Texas Panhandle (see references cited in Fisher, 1998); the high end of the Ra-226 activities ranges exceeded 4,500 pCi/L in the Ukraine and 5,000 pCi/L in the Texas Panhandle. In this report, several Ra-226 activities of approximately 4,000 pCi/L have been compiled for samples from non-Marcellus reser

voirs, but the Marcellus Shale data range higher, with several activities exceeding 10,000 pCi/L (table 2; fig. 7). Relationships between salinity and radium activity have been documented in a number of studies (for example, Kraemer and Reid, 1984; Fisher, 1998; Sturchio and others, 2001). Fisher (1998), however, pointed out that chloride or TDS concentrations “best predict radium activity in waters from reservoirs that are lithologically relatively homogeneous.” Despite their origin in reservoirs of varying ages and lithologies, the non-Marcellus Shale data indicate a positive correlation between salinity and both total radium and Ra-226 activities. Salinity (TDS) is plotted with total radium and Ra-226 in figures 7 A

– B . Use of the longest-lived isotope, Ra-226, may reduce some of the scatter induced in the data by sample collection at varying, or unknown, time intervals since brine production at the wellhead. A year after production at the wellhead, for example, the activities of the shorter-lived Ra-228 isotope would be reduced by approximately 11 percent because of natural decay. Analysis of covariance (ANCOVA 6 

# ) was used to statisti

cally examine the effect of Marcellus versus non-Marcellus sample origin on the linear relationship between TDS and radium activity. The resulting linear regression models yield nearly identical slopes in the trends of log total radium in relation to log TDS and log Ra-226 in relation to log TDS. However, the regression intercepts for the Marcellus Shale data are 0.4 and 0.55 log units (2.5 and 3.5 times, respectively) higher for total radium and Ra-226, respectively, than for the non-Marcellus samples. Produced water samples from the Marcellus Shale are, therefore, enriched in radium to a statistically significant degree (p<0.05) relative to samples

from other formations in the basin. This relative enrichment is also illustrated in figure 8 A

. An important mechanism by which salinity controls radium activity involves competition between Ra +2 

# and other multivalent ions for adsorption sites primarily on clay minerals (Kraemer and Reid, 1984). In low salinity fluids,

radium tends to be adsorbed onto mineral surfaces and with increasing salinity radium is progressively desorbed and released into solution. Sturchio and others (2001) presented a salinity-dependent distribution coefficient (K) between dissolved radium and radium adsorbed onto clay particles and oxide grain coatings. The logs of K and TDS show a linear relationship with negative slope, indicating less adsorption of radium at higher salinities and, therefore, more radium in solution (Sturchio and others, 2001, fig. 7). In a study of saline groundwater systems in the mid

continent with TDS concentrations reaching 250,000 mg/L, Sturchio and others (2001, fig. 5) used equilibrium speciation

calculations to demonstrate that Ra +2 

# was the predominant dissolved radium species, independent of salinity. In their analysis, Ra +2 

# never accounted for less than 77 percent of the total dissolved radium over a range of fluid chemistries. The next most abundant species, RaCl + 

# , gained significance with increasing salinity and Cl – 

# /SO
4 –2 

# ratios. Additionally, Sturchio and others (2001) reported that radium forms strong organic complexes at elevated salinities, which may be significant because limited, unpublished data for organic compounds in Appalachian Basin produced waters have shown significant concentrations of acetate and other anions of carboxylic acids. Dissolved radium measured in produced water samples originates from the decay of the parent isotopes, U-238 and Th-232, in uranium- and thorium-bearing minerals or organic material contained in the host formation. The physical transfer of radium from the solid to the aqueous phase is discussed and illustrated in Fisher (1998, fig. 2) and Sturchio and others (2001). Uranium and thorium, unlike radium, are poorly soluble in the oxygen-poor, reducing conditions that

6 

# See Crawley (2007), for example, for additional discussion of the

ANCOVA and related statistical methods.

# Discussion **13**

**Figure 7.** ( A ) Log activity of total radium (Ra-226 + Ra-228) in relation to log total dissolved solids and ( B ) log activity of Ra-226 in relation to log total dissolved solids. Linear regression lines are shown for data from the Marcellus Shale (red), and for non-Marcellus Shale (blue) data; the lines are solid over the range of the data and dashed where extrapolated. Radium analyses listed as “ND” or not detected (well nos. 2 and 14) indicate values below the reported level of quantification (LOQ), 1 pCi/L. These points were replaced by one-half of the LOQ, or 0.5 pCi/L, and are plotted as open squares, but are not included in the regression. A reported Ra-226 activity of 0 (well no. 123) was replaced by 0.5 pCi, and is plotted as an open circle, but was not included in the regression. M a r c e l l u s S h a l e D a t a 

# EXPLANATION

N o n

- M a r c e l l u s S h a l e D a t a

M a r c e l l u s N D
N o n

- M a r c e l l u s N D

M a r c e l l u s S h a l e D a t a 

# EXPLANATION

N o n

- M a r c e l l u s S h a l e D a t a

M a r c e l l u s N D
N o n

- M a r c e l l u s N D



# Log Ra-226 = 1.56 x Log TDS – 5.60

Log Ra-226 = 1.56 x Log TDS – 5.05 Log total Ra = 1.55 x Log TDS – 4.86

Log total Ra = 1.55 x TDS – 5.26



# Figure 7. **A**

**B**

– 1

. 0

0

. 0 1

. 0 2

. 0 3

. 0 4

. 0 5

. 0

3

. 0 4

. 0 5

. 0 6

. 0 

# Log total dissolved solids (TDS), in milligrams per literLogRa-226, in picocuries per liter



# 0

. 1 1

. 0 1 0 1 0 0 1

, 0 0 0 1 0

, 0 0 0 1 0 0

, 0 0 0 1

, 0 0 0 1 0

, 0 0 0 1 0 0

, 0 0 0 1

, 0 0 0

, 0 0 0 

# Total dissolved solids (TDS), in milligrams per literRa-226, in picocuries per lite 

# – 1

. 0

0

. 0 1

. 0 2

. 0 3

. 0 4

. 0 5

. 0

3

. 0 4

. 0 5

. 0 6

. 0 

# Log total dissolved solids (TDS) , in milligrams per literLogtotalradium, in picocuries per liter



# 0

. 1 1

. 0 1 0 1 0 0 1

, 0 0 0 1 0

, 0 0 0 1 0 0

, 0 0 0 1

, 0 0 0 1 0

, 0 0 0 1 0 0

, 0 0 0 1

, 0 0 0

, 0 0 0 

# T otal dissolved solids (TDS), in milligrams per literTotalradium, in picocuries per liter

# 14 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

**Figure 8.** ( A ) Total radium and ( B ) Ra-228/Ra-226 plotted against the age of the producing formation. For formations with large numbers of analyses, the median is shown as a solid black dot. Upper Devonian sandstones Middle Devonian, Marcellus Shale Middle Devonian, Huntersville Chert Middle Devonian, Onondaga Limestone Lower Devonian, Oriskany/Ridgely Sandstone Lower Devonian, Helderberg Limestone Upper Silurian, Bass Islands/Akron Dolomite Lower Silurian, Medina/Tuscarora Sandstone Upper Orodvician, Queenston Shale Ordovician, undifferentiated Upper Cambrian, Theresa Sandstone Unknown age Median 

# EXPLANATION Upper Devonian sandstones Middle Devonian, Marcellus Shale Middle Devonian, Huntersville Chert Middle Devonian, Onondaga Limestone Lower Devonian, Oriskany/Ridgely Sandstone Lower Devonian, Helderberg Limestone Upper Silurian, Bass Islands/Akron Dolomite Lower Silurian, Medina/Tuscarora Sandstone Upper Orodvician, Queenston Shale Ordovician, undifferentiated Upper Cambrian, Theresa Sandstone Unknown age Median 

# EXPLANATION



# Figure 8. **A**

**B**OrdovicianCambrianSilurianDevonian 

# Upper

Middle

Lower

Upper

Middle

Lower

Upper

Middle

Lower

Upper

Middle

UnknownOrdovicianCambrianSilurianDevonian 

# Upper

Middle

Lower

Upper

Middle

Lower

Upper

Middle

Lower

Upper

Middle

Unknown

0

. 0 1

. 0 2

. 0 3

. 0 4

. 0



# Ra-228/Ra-226Formation Age 

# T o t a l r a d i u m , in picocuries per literFormation Age



# 0 2

, 0 0 0 4

, 0 0 0 6

, 0 0 0 8

, 0 0 0 1 0

, 0 0 0 1 2

, 0 0 0 1 4

, 0 0 0 1 6

, 0 0 0

# References Cited **15**

are typical of oil- and gas-producing horizons and are likely to be more concentrated in mineral phases or organic matter than in solution (Langmuir and Herman, 1980; Kraemer and Reed, 1984; Fisher, 1998; Sturchio and others, 2001). Thus, dissolved radium that is in secular equilibrium with its parent isotopes of uranium and thorium at depth in a reservoir may be isolated from its parents when pumped to the surface. In addition to displaying higher radium activities for a given salinity, produced water samples from the Marcellus Shale have distinctly lower Ra-228/Ra-226 ratios (median of 0.16) than those of non-Marcellus samples (median of 1.1; figs. 8 A

– B ), reflecting the Th/U ratio of the reservoir litholo

gies. Organic carbon has long been known to play a role in concentrating uranium (Swanson, 1960, 1961; Szalay, 1964), and recent work by Bank and others (2010) has documented a close spatial association between the organic matter and uranium in the Marcellus Shale. As an organic-rich black shale, the Marcellus is readily identified on geophysical logs by its high gamma-ray signal (Schmoker, 1981; Harper, 2008). In eastern Pennsylvania, numerous minor occurrences of uranium have been reported in upper Paleozoic sandstones surveyed at roadside outcrops (Klemic, 1962). If the uranium enrichment is assumed to extend into the subsurface, itprovides a potential source for the radium reported in nonMarcellus Shale produced waters, and as discussed above, high formation water salinity can account for elevated radium

activities in solution. The Ra-228/Ra-226 ratios span a wide range among the non-Marcellus produced waters, and the highest values occur in samples from the Lower Silurian Medina Group/Tuscarora Sandstone. The median ratio for Medina/Tuscarora produced water samples is 1.61 (fig. 8 B ). Interestingly, this ratio is consistent with the data compiled by Vengosh and others (2009, fig. 4), which suggest an average isotopic ratio of approximately 1.6 for sandstones worldwide. The sandstones of the Upper Devonian Bradford Group have lower isotopic ratios (median, 0.78), possibly because of the interfingering of

sandstone with siltstone and shale beds in this interval.



# Summary

Produced water salinities from reservoirs in rocks of Cambrian-Devonion age in the Appalachian Basin commonly exceed 100,000 mg/L, and far exceed the salinities of many other oil- and gas-producing regions in the United States, including basins in California, the Great Plains, and Colorado Plateau. In many basins, radium activity is correlated with salinity, and particularly among samples from lithologically homogeneous reservoirs, salinity may be used as an indicator of radium activity. The data compiled for Pennsylvania indicate a relationship similar to that described in other basins; total radium and Ra-226 activities are linearly correlated with TDS. Salinity was not reported in the datasets for New York. The radium activities in non-Marcellus produced waters in this report are broadly comparable to those reported in other studies of deep sedimentary basins with highly saline formation water. In the produced water dataset for the Marcellus Shale in New York, total radium activities have a distinctly higher median (5,490 pCi/L) than reported for other formations in the Appalachian Basin, and range to higher values than reported in other basins. Produced waters from the Marcellus in Pennsylvania have similar ranges to the New York data, but a lower median value (1,727 pCi/L), interpreted as being due, at least in part, to dilution of formation water by formation water injected for hydraulic fracturing. In the data compiled here, Ra-228/Ra-226 ratios in produced water from the Marcellus Shale are most commonly less than 0.3, and samples from non-Marcellus reservoirs generally have Ra-228/Ra-226 ratios greater than 1. Elevated

total radium activities combined with low Ra-228/Ra-226 ratios characterize produced waters from the Marcellus Shale, and these characteristics might be used to constrain the origin of samples of unknown provenance.



# Acknowledgments

Funding for this project was provided by the USGS Energy Resources Program and the USGS Toxic Substances Hydrology Program. Reviews by Zoltan Szabo and James Otton and comments provided by Robert Zielinski are gratefully acknowledged. Insightful comment and discussion was provided by Richard Hammack and Daniel Soeder (U.S. Department of Energy National Energy Technology Laboratory).



# References Cited

Akovali, Y.A., 1996, Nuclear data sheets for A = 226: Nuclear Data Sheets, v. 77, p. 433–470, accessed July 13, 2011, at http://www.nndc.bnl.gov

.
Ames, L.L., McGarrah, J.E., and Walker, B.A., 1983, Sorption of trace constituents from aqueous solutions onto second

ary minerals II. Radium: Clays and Clay Minerals, v. 31,

p. 335–342.

Artna-Cohen, Agda, 1997, Nuclear data sheets for A = 228:

Nuclear Data Sheets, v. 80, p. 723–786, accessed July 13, 2011, at http://www.nndc.bnl.gov

.
Bank, Tracy, Malizia, Thomas, and Andresky, Lisa, 2010,

Uranium geochemistry in the Marcellus Shale—Effects on metal mobilization: Geological Society of America Abstracts with Programs, v. 42, no. 5, p. 502, accessed July 13, 2011, at http://gsa.confex.com/gsa/2010AM/ finalprogram/abstract_181465.htm

.

# 16 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

Bettencourt, A.O., Teixeira, M.M.G.R., Elias, M.D.T., and

Faisca, M.C., 1988, Soil to plant transfer of radium-226: Journal of Environmental Radioactivity, v. 6, p. 49–60.

Blauch, M.E., Myers, R.R., Moore, T.R., Lipinski, B.A., and Houston, N.A., 2009, Marcellus Shale Post-Frac Flowback Waters—Where is all the salt coming from and what are the implications?: Society of Petroleum Engineers, SPE Eastern Regional Meeting, September 23–25, 2009, Charleston,

W. Va., 20 p.

Breen, K.J., Angelo, C.G., Masters, R.W., and Sedam, A.C., 1985, Chemical and isotopic characteristics of brines from three oil- and gas-producing sandstones in eastern Ohio, with applications to the geochemical tracing of brine sources: U.S. Geological Survey Water-Resources Investi

gations Report 84–4314, 58 p., also available at http://pubs. er.usgs.gov/djvu/WRI/wrir_84_4314.djvu

.
Breit, G.N., 2002, Produced waters database: U.S. Geological Survey, accessed July 13, 2011, at http://energy.cr.usgs.gov/ prov/prodwat/index.htm

.
Buckwalter, T.F., and Moore, M.E., 2007, Ground-water

resources and the hydrologic effects of petroleum occur

rence and development, Warren County, northwestern Pennsylvania: U.S. Geological Survey Scientific Investiga

tions Report 2006–5263, 86 p., available at http://pubs.usgs. gov/sir/2006/5263/

.
Crawley, M.J., 2007, The R book: Hoboken, N.J., John Wiley & Sons, Inc., 492 p.

Dresel, P.E., 1985, Geochemistry of oilfield brines from

western Pennsylvania: University Park, Pennsylvania State University, M.S. thesis, 237 p.

Dresel, P.E., and Rose, A.W., 2010, Chemistry and origin of oil and gas well brines in western Pennsylvania: Pennsylva

nia Geological Survey, Open-File Report OFOG 10–01.0, 48 p., accessed July 13, 2011, at http://www.dcnr.state. pa.us/topogeo/pub/openfile/ofog10_01.aspx

.
Eaton, A.D., Clesceri, L.S., Rice, E.W., Greenberg, A.E., and

Franson, M.A.H., eds., 2005, Standard methods for the examination of water & wastewater (21st ed.): American Public Health Association, 1368 p.

Fisher, R.S., 1998, Geologic and geochemical controls on

naturally occurring radioactive materials (NORM) in produced water from oil, gas, and geothermal operations: Environmental Geosciences, v. 5, p. 139–150. Gilday, W.M., Edick, R.G., Rommel, R.E., Tetley, W.C., Kadlecek, J.A., Zeh, J.B., and Youngberg, B.A., 1999, An investigation of naturally occurring radioactive materials (NORM) in oil and gas wells in New York State: New York State Department of Environmental Conservation, 35 p. + appendices., accessed July 13, 2011, at http://www.dec. ny.gov/docs/materials_minerals_pdf/normrpt.pdf ; Executive summary only: http://www.dec.ny.gov/chemical/23473.html

.
Harper, J.A., 2008, The Marcellus Shale—An old “new” gas reservoir in Pennsylvania: Pennsylvania Geological Magazine, v. 38, no. 1, p. 2–13, accessed July 13, 2011,

at http://www.dcnr.state.pa.us/topogeo/pub/pageolmag/ pageolonline.aspx

.
Hayes, T., 2009, Sampling and analysis of water streams asso

ciated with the development of Marcellus Shale gas, Final Report, prepared for Marcellus Shale Coalition (formerly the Marcellus Shale Committee): Gas Technology Institute, 44 p. + appendices. (Report is available from the Pennsylva

nia Department of Environmental Protection.)

Hess, C.T., Michel, J., Horton, T.R., Prichard, H.M., and Coni

glio, W.A., 1985, The occurrence of radioactivity in public water supplies in the United States: Health Physics, v. 48,

p. 553–586.

Ivanovich, M., 1992, The phenomenon of radioactivity, in Ivanovich, M., and Harmon, R.S., eds., Uranium Series disequilibrium—Applications to Environmental Problems in Earth Sciences (2d ed.): Oxford, Clarendon Press, chap. 1, p. 1–33.

Klemic, Harry, 1962, Uranium occurrences in sedimentary

rocks of Pennsylvania: Geological Survey Bulletin 1107–D, p. 243–288.

Kraemer, T.F., 2005, Radium isotopes in Cayuga Lake, New

York—Indicators of inflow and mixing processes: Limnol

ogy and Oceanography, v. 50, p. 158–168.

Kraemer, T.F., and Reid, D.F., 1984, The occurrence and

behavior of radium in saline formation water of the

U.S. Gulf Coast region: Isotope Geoscience, v. 2,

p. 153–174.

Krieger, H.L., and Whittaker, E.L., 1980, Prescribed proce

dures for measurement of radioactivity in drinking water: U.S. Environmental Protection Agency, EPA–600/4–80–032, 111 p.

Krishnaswami, S., Graustein, W.C., Turekian, K.K., and Dowd, J.F., 1982, Radium, thorium, and radioactive isotopes in ground waters—Application to the in situ determination of adsorption-desorption rate constants and retardation factors: Water Resources Research, v. 18,

p. 1633–1675.

# References Cited **17**

Langmuir, Donald, and Herman, J.S., 1980, The mobility of

thorium in natural waters at low temperatures: Geochimica et Cosmochimica Acta, v. 44, p. 1753–1766.

Langmuir, Donald, and Riese, A.C., 1985, The thermodynamic

properties of radium: Geochimica et Cosmochimica Acta,

v. 49, p. 1593–1601.

Legall, F.D., Barnes, C.R., and MacQueen, R.W., 1981, Ther

mal maturation, burial history and hotspot development, Paleozoic strata of southern Ontario-Quebec, from conodont

and acritarch colour alteration studies: Bulletin of Canadian Petroleum Geology, v. 29, p. 492–539.

Linsalata, P., Morse, R.S., Ford, H., Eisenbud, M., Franca, E.P., deCastro, M.B., Lobao, N., Sachett, I., and Carlos, M., 1989, An assessment of soil-to-plant concentration ratios for some natural analogues of the transuranic elements: Health Physics, v. 56, p. 33–46.

Milici, R.C., Ryder, R.T., Swezey, C.S., Charpentier, R.R., Cook, T.A., Crovelli, R.A., Klett, T.R., Pollastro, R.M., and Schenk, C.J., 2003, Assessment of undiscovered oil and gas resources of the Appalachian Basin Province, 2002:

U.S. Geological Survey Fact Sheet FS 009–03, 2 p., avail

able at http://pubs.usgs.gov/fs/fs-009-03/FS-009-03-508.pdf

.
Moore, W.S., 1984, Radium isotopic measurements using germanium detectors: Nuclear Instruments and Methods in Physics Research, v. 223, p. 407–411.

National Nuclear Data Center, [n.d.], Chart of nuclides data

base, accessed July 14, 2011, at http://www.nndc.bnl.gov/

chart/

.
New York State Department of Environmental Conservation (NYSDEC), 2009, Draft Supplemental Generic Environ

mental Impact Statement (SGEIS) on the oil, gas, and solution mining regulatory program (September 2009), Well permit issuance for horizontal drilling and high-volume hydraulic fracturing to develop the Marcellus Shale and other low-permeability gas reservoirs: New York State Department of Environmental Conservation, Division of Mineral Resources, Bureau of Oil and Gas Regulation, Appendix 13, NYS Marcellus radiological data from production brine, accessed July 14, 2011, Full document: http://www.dec.ny.gov/energy/58440.html

.
Osborn, S.G., and McIntosh, J.C., 2010, Chemical and isoto

pic tracers of the contribution of microbial gas in Devonian organic-rich shales and reservoir sandstones, northern Appa

lachian Basin: Applied Geochemistry, v. 25, p. 456–471.

Pennsylvania Department of Environmental Protection (PA DEP), 1992, NORM survey summary, September 1, 1992; reproduced in IOGA NEWS (Independent Oil and Gas Association of Pennsylvania), April 1995, available at http://www.dep.state.pa.us/dep/deputate/minres/OILGAS/ NORM.pdf

. Poth, C.W., 1962, The occurrence of brine in western Penn

sylvania: Pennsylvania Geological Survey, Fourth Series, Bulletin M–47, 53 p.

Pritz, M.E., 2010, Geochemical modeling and analysis of the frac water used in the hydraulic fracturing of the Marcellus Formation, Pennsylvania: Lewisburg, Bucknell University, B.S. Honors Thesis, 228 p.

Rose, A.W., and Korner, L.A., 1979, Radon in natural waters as a guide to uranium deposits in Pennsylvania, in Watter

son, J.R., and Theobald, P.K., eds. Proceedings of the Sev

enth International Geochemical Exploration Symposium: Golden, Colo., p. 65–75.

Rowan, E.L., Engle, M.A., and Kirby, C.S., 2010, Inorganic geochemistry of formation waters from Devonian Strata in the Appalachian Basin—Preliminary observations from Pennsylvania, New York, and West Virginia [abs.]: Geological Society of America, Annual meeting,

October 31–November 3, 2010, Paper No. 204-8, Abstracts with Programs, v. 42, no. 5, p. 487, accessed July 14, 2011, at http://gsa.confex.com/gsa/2010AM/finalprogram/ abstract_174638.htm

.
Sanders, L.L., 1991, Geochemistry of formation waters from

the Lower Silurian Clinton Formation (Albion Sandstone), eastern Ohio: AAPG Bulletin, v. 75, p. 1593–1608.

Schmoker, J.W., 1981, Determination of organic-matter con

tent of Appalachian Devonian shales from gamma-ray logs: AAPG Bulletin, v. 65, p. 1285–1298.

Stout, W.E., Lamborn, R.E., and Schaaf, D., 1932, Brines of

Ohio (Preliminary Report): Geological Survey of Ohio Bul

letin 37, 123 p.

Sturchio, N.C., Banner, J.L., Binz, C.M., Heraty, L.B., and

Musgrove, M., 2001, Radium geochemistry of ground waters in Paleozoic carbonate aquifers, midcontinent, USA: Applied Geochemistry, v. 16, p. 109–122.

Swanson, V.E., 1960, Oil yield and uranium content of black

shales: U.S. Geological Survey Professional Paper 356–A, 49 p.

Swanson, V.E., 1961, Geology and geochemistry of uranium

in marine black shales, A review: U.S. Geological Survey Professional Paper 356–C, 112 p.

Szalay, A., 1964, Cation exchange properties of humic acids

and their importance in the geochemical enrichment of

UO
2 ++ 

# and other cations: Geochimica et Cosmochimica Acta, v. 28, p. 1605–1614.

Thompson, Michael, and Howarth, R.J., 1978, A new approach to the estimation of analytical precision: Journal of Geochemical Exploration, v. 9, p. 23–30.

# 18 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion**

Tracy, B.L., Prantl, F.A., and Quinn, J.M., 1983, Transfer of

226 

# Ra, 210 

# Pb, and uranium from soil to garden produce— Assessment of risk: Health Physics, v. 44, p. 469–477.

U.S. Environmental Protection Agency, 1976, National Interim Primary Drinking Water Regulations, U.S. Envi

ronmental Protection Agency, Office of Water Supply,

EPA/570/9–76/093.

U.S. Nuclear Regulatory Commission, [n.d.], Radium-226: U.S. Nuclear Regulatory Commission, accessed July 14, 2011, at http://www.nrc.gov/reading-rm/doc-collections/cfr/ part020/appb/Radium-226.html

. Vengosh, A., Hirschfeld, D., Vinson, D., Dwyer, G., Raanan, H., Rimawi, O., Al-Zoubi, A., Akkawi, E., Marie, A., Haquin, G., Zaarur, S., and Ganor, J., 2009, High naturally occurring radioactivity in fossil groundwater from the Middle East: Environmental Science and Technology, v. 43, p. 1769–1775.

Walter, L.M., Stueber, A.M., and Huston, T.J., 1990, Br-Cl-Na systematics in Illinois basin fluids—Constraints on fluid origin and evolution: Geology, v. 18, p. 315–318.

# Table 1 **19 Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: PA DEP (2009–2010)111/18/2009PAClintonChapman–77.5641.37Storage tankMarcellus Sh.Devonian, M.Gas211/20/2009PAClintonBeech Creek–77.6841.20Storage tankMarcellus Sh.Devonian, M.Gas36/1/2009PABradfordBurlington–76.6041.74Marcellus Sh.Devonian, M.Gas48/24/2009PALycomingPenn–76.6341.28Marcellus Sh.Devonian, M.Gas5.13/18/2009PALycomingPenn–76.6641.27Marcellus Sh.Devonian, M.Gas5.23/30/2009PALycomingPenn–76.6641.27Marcellus Sh.Devonian, M.Gas612/21/2009PATiogaCharleston–77.2141.79Marcellus Sh.Devonian, M.Gas712/21/2009PATiogaRichmond–77.1341.78Marcellus Sh.Devonian, M.Gas89/8/2009PACentreBurnside–78.0541.13ImpoundmentMarcellus Sh.Devonian, M.Gas91/8/2010PAForestJenks–79.1641.55Tank or lined pitMarcellus Sh.Devonian, M.Oil1012/30/2009PAPotterEast Fork–77.8841.61Marcellus Sh.Devonian, M.Gas11.14/9/2009PAWashingtonCross Creek–80.3940.26Marcellus Sh.Devonian, M.Gas11.26/29/2009PAWashingtonCross Creek–80.3940.26Marcellus Sh.Devonian, M.Gas1212/30/2009PATiogaGainesville–77.5641.69Marcellus Sh.Devonian, M.Gas1312/30/2009PATiogaGainesville–77.5841.68Tuscarora Fm.Silurian, L.Gas141/7/2010PAPotterWest Branch–77.6241.67Marcellus Sh.Devonian, M.Gas1512/16/2009PAClearfieldLawrence–78.4541.17Marcellus Sh.Devonian, M.Gas1612/22/2009PAWestmorelandWashington–79.5740.49Marcellus Sh.Devonian, M.Gas1712/7/2009PAWestmorelandWashington–79.5640.50Marcellus Sh.Devonian, M.Gas1811/13/2009PAWestmorelandBell–79.5540.51Marcellus Sh.Devonian, M.Gas199/18/2009PAWestmorelandHempfield–79.6540.28Marcellus Sh.Devonian, M.Gas207/16/2009PAWestmorelandHempfield–79.5740.50Marcellus Sh.Devonian, M.Gas217/23/2009PAIndianaRayne–79.0440.75Marcellus Sh.Devonian, M.Gas227/31/2009PAWestmorelandWashington–79.5840.50Marcellus Sh.Devonian, M.Gas238/13/2009PAWestmorelandBell–79.5440.50Marcellus Sh.Devonian, M.Gas

# 20 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: NYSDEC (2009)244/1/2009NYSteubenAvoca–77.4142.40Marcellus Sh.Devonian, M.Gas254/1/2009NYSteubenAvoca–77.4242.41Marcellus Sh.Devonian, M.Gas264/2/2009NYChenangoOxford–75.6142.45Marcellus Sh.Devonian, M.Gas27.110/7/2008NYSteubenCaton–77.0442.05Marcellus Sh.Devonian, M.Gas27.24/1/2009NYSteubenCaton–77.0442.05Marcellus Sh.Devonian, M.Gas2810/8/2008NYSchuylerOrange–77.0842.28Marcellus Sh.Devonian, M.Gas294/1/2009NYSteubenWoodhull–77.4442.02Marcellus Sh.Devonian, M.Gas304/1/2009NYSteubenTroupsburg–77.4742.02Marcellus Sh.Devonian, M.Gas314/6/2009NYSchuylerDix–76.9442.34Marcellus Sh.Devonian, M.Gas324/6/2009NYSchuylerDix–76.9442.34Marcellus Sh.Devonian, M.Gas333/26/2009NYSchuylerOrange–77.0742.29Marcellus Sh.Devonian, M.Gas344/6/2009NYSchuylerReading–76.9142.44Marcellus Sh.Devonian, M.Gas3510/8/2008NYSchuylerOrange–77.0642.29Marcellus Sh.Devonian, M.GasSource: NYSDEC (1999)36NYCattaraugus–78.6642.42Brine tankMedina Gp.Silurian, L.Gas37NYCattaraugus–78.6642.42Brine tankMedina Gp.Silurian, L.Gas38NYCattaraugus–78.6842.44Brine tankMedina Gp.Silurian, L.Gas39NYCattaraugus–78.6842.47Brine tank(rusted)Medina Gp.Silurian, L.Gas40NYCattaraugus–78.7242.46Brine tankMedina Gp.Silurian, L.Gas41NYCattaraugus–78.7142.46Brine tankMedina Gp.Silurian, L.Gas42NYErie–78.4742.93Bottom of brinetankMedina Gp.Silurian, L.Gas43NYGenesee–78.4642.93Bottom of brinetankMedina Gp.Silurian, L.Gas44NYGenesee–78.4643.03Brine tank,subsurfaceMedina Gp.Silurian, L.Gas45NYGenesee–78.4543.02Brine tankMedina Gp.Silurian, L.Gas46NYGenesee–78.2543.05Brine tankMedina Gp.Silurian, L.Gas

# Table 1 **21 Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: NYSDEC (1999)—Continued47NYGenesee–78.2643.05Brine tank,subsurfaceMedina Gp.Silurian, L.Gas48NYGenesee–78.3042.95Brine tank,subsurfaceMedina Gp.Silurian, L.Gas49NYGenessee–78.3042.88Brine tankMedina Gp.Silurian, L.Gas50NYWyoming–78.1042.82Brine tank(rusted)Theresa Ss.Cambrian, U.Gas51NYWyoming–78.1042.83Brine tankTheresa Ss.Cambrian, U.Gas52NYWyoming–78.1242.82Brine tankMedina Gp.Silurian, L.Gas53NYWyoming–78.1142.81Brine tankTheresa Ss.Cambrian, U.Gas54NYWyoming–78.3642.74Brine tankMedina Gp.Silurian, L.Gas55NYCayuga–76.6442.91Spigot, base ofbrine tankQueenston Sh.Ordovician, U.Gas56NYCayuga–76.6542.91Spigot, base ofbrine tankQueenston Sh.Ordovician, U.Gas57NYSeneca–76.8642.84Spigot, base ofbrine tankQueenston Sh.Ordovician, U.Gas58NYSeneca–76.8542.84Spigot, base ofbrine tankQueenston Sh.Ordovician, U.Gas59NYSeneca–76.9042.78Spigot, base ofbrine tankRochester Sh.Silurian, L.Gas60NYGenesee–77.9842.93Brine tankMedina Gp.Silurian, U.Gas61NYLivingston–77.9142.94Brine tankMedina Gp.Silurian, L.Gas62NYOntario–77.5442.81Brine tankMedina Gp.Silurian, L.Gas63NYChautauqua–79.5242.38Bottom of brinetankMedina Gp.Silurian, L.Gas64NYChautauqua–79.7242.27Bottom of brinetankMedina Gp.Silurian, L.Gas65NYChautauqua–79.5842.16Brine tankMedina Gp.Silurian, L.Gas

# 22 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: NYSDEC (1999)—Continued66NYChautauqua–79.5442.08Brine tankBass IslandsDolo.Silurian, U.Oil67NYChautauqua–79.4342.09Brine tankMedina Gp.Silurian, L.Gas68NYChautauqua–79.4742.13Brine tankBass IslandsDolo.Silurian, U.Oil69NYChautauqua–79.4242.16Brine drain tankBass IslandsDolo.Silurian, U.Oil70NYErie–78.8942.54Brine tankOnondaga Ls.Devonian, M.Gas71NYChautauqua–79.0142.38Brine tankMedina Gp.Silurian, L.Gas72NYChautauqua–79.1642.31Brine tankMedina Gp.Silurian, L.Gas73NYChautauqua–79.1942.31Bottom of stocktankDevonian, U.,undiv.Devonian, U.Gas–Oil74NYChautauqua–79.2442.23Bottom of stocktankBass IslandsDolo.Silurian, U.Oil75NYChautauqua–79.3642.17Brine tankBass IslandsDolo.Silurian, U.Gas–Oil76NYChautauqua–79.3842.22Brine tankMedina Gp.Silurian, L.Gas77NYChautauqua–79.3042.16Brine tankMedina Gp.Silurian, L.Gas78NYChautauqua–79.2742.07Brine tankMedina Gp.Silurian, L.Gas79NYErie–78.7942.56Brine tankMedina Gp.Silurian, L.Gas80NYAllegany–77.9242.01Brine tankOriskany Ss.Devonian, L.Gas81NYAllegany–77.9542.01Brine tankOriskany Ss.Devonian, L.Gas82NYTioga–76.2642.03Brine tankHelderberg Ls.Devonian, L.Gas83NYTioga–76.3142.00Brine tankHelderberg Ls.Devonian, L.Gas

# Table 1 **23 Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: PA DEP (1992)84PAAlleghenyS. Fayette–80.2140.36Diked areaGas85PAArmstrongCowanshannock–79.2640.79TankDevonian, U.Gas86PAArmstrongCowanshannock–79.2540.78TankCatskill/LockHaven Fms.Devonian, U.Gas87PACambriaSusquehanna–78.7640.70TankVenango Gp.Devonian, U.Gas88PACambriaBarr–78.8340.66TankLock HavenFm.Devonian, U.Gas89PACentreCurtin–77.7741.11TankCatskill/LockHaven Fms.Devonian, U.Gas90PACentreBurnside–77.8741.12TankCatskill/LockHaven Fms.Devonian, U.Gas91PAClearfieldJordan–78.6140.83TankCatskill/LockHaven Fms.Devonian, U.Gas92PAClearfieldBurnside–78.7240.84TankLock HavenFm.Devonian, U.Gas93PAClintonBeech Creek–77.7041.17TankLock HavenFm.Devonian, U.Gas94PAClintonBeech Creek–77.7441.15TankMedina Gp.Silurian, L.Gas95PACrawfordBeaver–80.4141.81TankMedina Gp.Silurian, L.Gas96PAElkHighland–78.8341.54Separator tankBradford Gp.Devonian, U.Oil97PAElkHighland–78.9341.51TankDevonianOil98PAErieMillcreek–80.1742.08TankMedina Gp.Silurian, L.Gas99PAErieConneaut–80.4441.89TankHuntersvilleChertDevonian, M.Gas100PAFayetteSpringfield–79.3639.97TankOriskany Ss.Devonian, L.Gas101PAFayetteSpringfield–79.4039.96TankHuntersvilleChertDevonian, M.Gas102PAForestHowe–79.1441.56Tank batteryWarren sandDevonian, U.Oil103PAForestKingsley–79.2941.58TankDevonian, U.,undiv.Devonian, U.Oil104PAIndianaCherryhill–78.8240.74TankKane sandDevonian, U.Gas

# 24 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: PA DEP (1992)—Continued105PAIndianaBurrell–79.1740.48TankFifty Foot sandDevonian, U.Gas106PAIndianaWhite–79.1940.65TankGas107PAJeffersonBell–78.9040.97TankDevonian, U.,undiv.Devonian, U.Gas108PAMcKeanWetmore–78.8741.63Separator pitUnknownOil109PAMcKeanLafayette–78.7241.83PitOriskany Ss.Devonian, L.Oil110PASomersetMiddlecreek–78.9240.06TankOriskany Ss.Devonian, L.Gas111PASomersetLincoln–79.0740.08TankHuntersvilleChertDevonian, M.Gas112PATiogaUnion–76.9641.57Drill pitOrdovicianGas113PAVenangoCornplanter–79.5941.48SeparatorRed Valley sandDevonian, U.Oil114PAVenangoAllegheny–79.5541.57PitVenango Gp.Devonian, U.Oil115PAWarrenPleasant–79.1941.81PitMedina Gp.Silurian, L.Oil116PAWarrenSouthwest–79.5741.63TankMedina Gp.Silurian, L.Gas117PAWarrenWatson–79.2541.76PitDevonian, U.,undiv.Devonian, U.Oil118PAWashingtonCecil–80.2440.33SeparatorDevonian, U.Oil119PAWestmorelandWashington–79.5840.49TankVenango Gp.Devonian, U.Gas120PAWestmorelandHempfield–79.5340.26TankVenango Gp.Devonian, U.GasSource: Dresel and Rose (2010)1211982PAIndianaBanks–78.8540.87WellheadDevonian, U.,undiv.Devonian, U.Gas1221982PAIndianaSouth Mahoning–79.1440.78WellheadDevonian, U.,undiv.Devonian, U.Gas1231982PAWarrenPleasant–79.2141.82WellheadGlade sandDevonian, U.Oil1241982PACrawfordFairfield–80.1441.49WellheadMedina Gp.Silurian, L.Gas1251982PACentreBoggs–77.8441.00SeparatorTuscarora Fm.Silurian, L.Gas1261982PASomersetBlack–79.1139.93SeparatorRidgeley Ss.Devonian, L.Gas

# Table 1 **25 Table 1.** Well locations and related information compiled for samples used in this study. The Well/Sample ID column assigns a unique number to each sample;digits to the right of the decimal (for example, “5.1,” “5.2”) indicate a time series or multiple samples taken from a well ondifferent dates to characterize changesover time.—Continued[Sh., shale; Ss., sandstone; Dolo., dolomite; Fm., formation; Gp., Group; L., lower; M., middle; U., upper; undiv., undivided]**Well / Sample ID** **Sample collection date** **State County** **Township Longitude** **Latitude Description of** **sample site Producing** **formation Producing** **formation age Well** **type**Source: Pritz (2010), this study12704/09PABradfordMarcellus Sh.Devonian, M.Gas12804/09PABradfordMarcellus Sh.Devonian, M.Gas12904/09PABradfordMarcellus Sh.Devonian, M.Gas13004/09PABradfordMarcellus Sh.Devonian, M.Gas13104/09PABradfordMarcellus Sh.Devonian, M.GasSource: This study132.112/8/2010PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.212/29/2010PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.312/30/2010PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.412/31/2010PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.51/1/2011PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.61/2/2011PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.71/4/2011PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.81/12/2011PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas132.91/17/2011PAGreene–80.0539.88SeparatorMarcellus Sh.Devonian, M.Gas

# 26 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: PA DEP (2009–2010)154,00043632.21218.25560.28SM2540C; EPA904.0, 903.0216,2001421,32286ND1.8ND0.3SM2540C, 7110C; EPA 900.0, 903.0, 904.03333,00019,2202,8437,9441,320501.3373.3870.73SM2540C; EPA 900.0 903.0, 904.0461,8006,1597431,32519043011.0518.94820.12SM2540C; EPA 900.0, 903.0, 904.05.138,20045412614978664.02.20.9680.03SM2540C; EPA 900.0, 903.0, 904.05.282,6001,6443717452422399.7386.32770.16SM2540C; EPA 900.0, 903.0, 904.0640,8807,51275073216,9203,2831,12522718,0450.07EPA 903.1, 904.0721,9604,07498075711,1202,2041,28726112,4070.12EPA 903.1, 904.08124,0001,525110657762,1820.43SM18 2540C; EPA 901.1 Mod.9284,00011,8102,4821,0607594,1847891,0742025,2580.26SM20 2540C; EPA 903.1, 904.010157,0007,3304601,1801808,5100.16SM18 2540C; EPA 901.1 Mod.11.1157,00095186703691,6540.74SM18 2540C; EPA 901.1 Mod.11.2200,0001,2801301,1101202,3900.87SM18 2540C; EPA 901.1 Mod.12183,0007,5301,1412,68337256226648671,2101.15SM18 2540C; EPA 900.0, 903.0, 904.013358,00010,3562,18611,595723892322,5891283,4812.90SM18 2540C; EPA 900.0, 903.0, 904.0141,470ND3784ND0.31ND0.391.00SM2540C; EPA 900.0, 903.0, 904.015288,90019,2407,0491,2681061,3740.08SM2540C1624,70031845334059010324168322711.63SM2540C; EPA 900.0Mod., 903.1, 904.01788,5003,6401,004ND6311,042197298591,3400.29SM2540C; EPA 900.0Mod., 903.1, 904.018116,0002,3208002,0779291,037200515971,5520.50SM2540C; EPA 900.0Mod., 903.1, 904.01932,50073317581615541045.51.95590.01SM2540C; EPA 900.0Mod., 903.1, 904.02045,400845213379116664.051.40.3670.02SM2540C; EPA 900.0, 903.0, 904.02146,460820249505140762.7232.4990.30SM2540C; EPA 900.0, 903.0, 904.02247,80058516353683361.752.70.2390.08SM2540C; EPA 900.0, 903.0, 904.023125,1002,1036311,5743352296.8566.52850.25SM2540C; EPA 900.0, 903.0, 904.0

# Table 2 **27 Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: NYSDEC (2009)2470487540.1630.200.0290.220.1920.1752554.63759580.1950.160.4280.340.6232.195263,9148137152021,779343201391,9800.11327.117,9408,6344,7653,8292,4724848741743,3460.35427.23,9681,1026185997,8851,568234518,1190.03028206,44614,5303,7924,5611,6342,6474947821573,4290.295299,4262,0652,7808794,0498078261604,8750.204307,9741,8001,6277365,3521,051138375,4900.0263110,9702,3631,1707016,1251,225516996,6410.0843220,7504,1172,38986110,1602,0261,25223711,4120.12333205,10218,3303,694ND65413,5102,65592917914,4390.0693416,5503,3551,32371115,1402,98995718116,0970.06335123,00023,48012,0002,90316,0302,99591217716,9420.057Source: NYSDEC (1999)36669881,1002501,7691.644γ-spectrometry3740268402γ-spectrometry381,16493429271,5930.369γ-spectrometry39398642341826320.588γ-spectrometry4025947259γ-spectrometry4140960409γ-spectrometry42413618562221,2692.073γ-spectrometry43260437031949632.704γ-spectrometry44637163γ-spectrometry45169865652547343.343γ-spectrometry463061265682488741.856γ-spectrometry471751002551794301.457γ-spectrometry4834755347γ-spectrometry49290504601727501.586γ-spectrometry

# 28 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: NYSDEC (1999)—Continued50764814332421,1970.567γ-spectrometry51450663263197760.724γ-spectrometry52477656513061,1281.365γ-spectrometry53708713502971,0580.494γ-spectrometry54238117269525071.130γ-spectrometry551,2401001,2901302,5301.040γ-spectrometry56823691,3334502,1561.620γ-spectrometry57557679332301,4901.675γ-spectrometry58465659772301,4422.101γ-spectrometry59NDγ-spectrometry60369618902271,2592.412γ-spectrometry61538726252071,1631.162γ-spectrometry6214692146γ-spectrometry631872080292670.427γ-spectrometry6432436503308271.552γ-spectrometry65444471,690552,1343.806γ-spectrometry661,550110319601,8690.206γ-spectrometry67366451,660472,0264.536γ-spectrometry68654361,440502,0942.202γ-spectrometry691,04040387321,4270.372γ-spectrometry7064.227.083121471.294γ-spectrometry7114817100232480.676γ-spectrometry7216035574317343.588γ-spectrometry731852086252710.467γ-spectrometry7495364444451,3970.466γ-spectrometry7558567585γ-spectrometry769511091,5001702,4511.577γ-spectrometry77484321,420501,9042.934γ-spectrometry7815635504366603.231γ-spectrometry

# Table 2 **29 Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: NYSDEC (1999)—Continued791113560231700.538γ-spectrometry8090152250421,1510.278γ-spectrometry8169126154308450.223γ-spectrometry823,7601001,110604,8700.295γ-spectrometry831,6201101,790603,4101.105γ-spectrometrySource: PA DEP (1992)84143,4325122027140.395853151654800.524862013330.65087175,2961,4089042,3120.64288195,4041,1541,0832,2370.93889222,6721631262890.77390252,9801,4896362,1250.42791185,1462,0151,7493,7640.86892230,924107771840.72093194,9027314911,2220.67294153,0968115301,3420.65395396,0125991,6832,2822.8109631,5021518331.1509725,1592326491.14398390,9286281,4782,1062.35599378,1485881,4832,0722.521100341,9184,6852,0386,7230.435101354,0345662,1102,6763.728102130,5884242841.00010386,9883956951.427104186,7362,0192,1964,2151.088105198,6682,5751,8664,4410.725106121,9284503137630.696

# 30 **Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin: Summary and Discussion Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: PA DEP (1992)—Continued1071,2808482,1280.66310836,470812201.4461091851843700.995110176,6762031,5431,7467.601111182,2741,9884992,4870.2511121,1371,4572,5941.281113114,2081230422.50011436,28254771311.42611559,5543427610.794116395,4407959681,7631.219117125,2642751874620.680118134,1642554567111.788119221,134170462160.271120402,148857719280.083Source: Dresel and Rose (2010)121253,0001,9001,900122244,00020020012391,00000.0124257,000500500125259,0005,3005,300126302,0005,0005,000Source: Pritz (2010), this study127122,5272,65311318222,9710.120γ-spectrometry128250,1123,08221935274,0180.303γ-spectrometry129134,8801,95826572372,5300.292γ-spectrometry130222,6811,48613472231,9570.317γ-spectrometry131117,2591,7566377102,1330.215γ-spectrometry

# Table 2 **31 Table 2.** Ra-226, Ra-228, gross alpha, and gross beta activities measured in samples of produced water for wells listed in table 1. Analytical uncertainties are includedwhen known.—Continued[TDS, total dissolved solids; mg/L, milligram per liter; pCi/L, picocurie per liter; ND, not detected]**Well / Sample** **ID TDS** **(mg/L) Gross** **alpha (pCi/L)** **+/– Gross** **beta (pCi/L)** **+/– Ra-226** **(pCi/L) +/–** **Ra-228 (pCi/L)** **+/– Total** **radium (pCi/L)** **Ra-228/ Ra-226** **Method, method codes**Source: This study132.11,31219300231,6120.229γ-spectrometry132.23,36321542193,9050.161γ-spectrometry132.34,37239577194,9490.132γ-spectrometry132.44,89238599295,4910.122γ-spectrometry132.55,11018626205,7360.123γ-spectrometry132.65,21031614325,8240.118γ-spectrometry132.73,10526686303,7910.221γ-spectrometry132.85,44628820176,2660.151γ-spectrometry132.95,27288846336,1180.160γ-spectrometry



# Manuscript approved on August 4, 2011.

Prepared by the USGS Science Publishing Network,

Raleigh Publishing Service Center
Edit and layout by Kay P. Naugle
Graphics by Francisco A. MaldonadoRowan and others**— Radium Content of Oil- and Gas-Field Produced Waters in the Northern Appalachian Basin** **—**Scientific Investigations Report 2011–5135