RADIOACTIVITY IN MARCELLUS SHALE 

CHALLENGE FOR REGULATORS AND WATER TREATMENT PLANTS

Marvin Resnikoffa

aRadioactive Waste Management Associates, Bellows Falls, VT 05101, USA 

ABSTRACT 

Studies by the U.S. Geological Survey and gamma logs of drillers show radium concentrations 

up to 32 times background concentrations in the Marcellus shale formation. Brought to the 

surface in rock cuttings, drilling fluids, flowback water and brine, radium can enter the 

environment in several forms. A fraction will be reinserted into deep disposal wells, or go to 

water treatment plants. Because of its high salinity, a portion will be spread on highways in the 

winter. The rock cuttings will go to solid waste landfills. Over the production cycle, a portion of 

Marcellus radium plates out on pipes. And an inert radioactive gas, radon, will enter homes 

when natural gas is used for heating and cooking. 

This paper examines the fate and transport of radionuclides brought to the surface, and the 

environmental impact in the environment. Regulators have the task of developing regulations 

that protect the health and safety of the population. The water treatment industry must develop 

processes for separating radium from large volumes of waste waters so that surface streams meet 

regulatory limits. This paper explores these different waste streams and potential resolutions of 

these differing problems. 

INTRODUCTION 

Geologists consider the Marcellus shale formation to be relatively highly radioactive and 

regionally extensive. Radioactivity in the Marcellus shale results from the high content of 

naturally occurring radioactive uranium and thorium, including their decay products, and 

potassium elements in the rock. In New York State the formation ranges from 25 to over 100 feet 

in thickness and the depth of the base varies from an outcrop to 1000-foot depth by Syracuse to 

4000-foot depth by the border with Pennsylvania (Hill, 2994). 

The areal extent of Marcellus shale is shown in Figure 1. As seen, the formation underlies the 

States of New York, Pennsylvania, eastern Ohio, West Virginia, Virginia, all the way into 

Alabama. 
Figure 1. Areal Extent of Marcellus Shale (NYSERDA, 2009)

The depth to the top of the Marcellus formation in New York State is shown in Figure 2. As 

seen, the formation is deeper as one goes south. 
Figure 2. Depth of Marcellus Shale in New York State (NYSERDA, 2009)

In addition to the depth of the Marcellus formation, the thickness varies as well. In New York 

State the Marcellus shale thickness increases from less than 25 feet in the western section of the 

State, Chautauqua County, to 300 feet in the southeastern section of the State, as seen in Figure 

3. The dots represent exploratory gas wells. 
Figure 3. Marcellus shale thickness in New York (NYSERDA, 2009)

RADIOACTIVITY IN MARCELLUS SHALE 

Most disinterested scientists agree that the Marcellus shale contains uranium-238, thorium-232 

and their decay products at concentrations significantly above background. The issue is: how 

much radioactivity above background? In general, the radioactivity throughout the vertical depth 

of rock cuttings appears to be equal to or less than 10 picocuries per gram, including K-40. 

However, at certain depths in each well, the activity is significantly higher. The gas industry 

knows it has reached the Marcellus shale horizon when cores show high gamma ray and high 

total organic carbon content (TOC). Consider the log from Beaver Meadows (Figure 4). This 

well is located near Norwich in Chenango County in upstate New York. 
Figure 4. Beaver Meadows Core (AAPG, 2010)

As one goes from the shale layer (Union Springs) to the limestone layer (Onondaga Limestone), 

one sees a major drop in gamma ray and total organic content. Without going into a discussion 

of GAPI units, 16.5 GAPI represents 1 pCi/g radium, and 400 GAPI is 24.2 pCi/g radium. As 

you can see, the GAPI is much greater than 400 units, and this also corresponds to very high 

TOC. These radium concentrations are far higher than background radium concentrations in 

New York State (Myrik, 1981), which are 0.85 pCi/g. Other gamma ray logs wells down to the 

Marcellus shale horizon in New York State such as the Shiavone 2, WGI11 and Bergstrasser 

wells show similar results. 

The logs mentioned above correspond to a geochemical study of trace elements and 

uranium in the Devonian shale of the Appalachian Basin (Leventhal, 1981) carried out in 1981 

by the United States Geological Survey (USGS). The Devonian layer refers to sediment formed 
350 million years ago from mud in shallow seas. Since the layers do not form in a line parallel 

to the ground surface, the depth at which Marcellus is found can vary from surface outcroppings 

to as deep as 7,000 feet or more below the ground surface along the Pennsylvania border in the 

Delaware River valley (NYDEC, 2011), and as deep as 9000 feet in Pennsylvania [2]. 

The USGS study analyzed seventeen cores from wells in Pennsylvania, New York, Ohio, 

West Virginia, Kentucky, Tennessee, and Illinois. The researchers collected a variety of 

geochemical data to be used for resource assessment and identification of possible environmental 

problems. Rather than direct gamma spectroscopy, uranium was measured in each core with a 

more appropriate and precise method, delayed-neutron analysis. I use data from the USGS since 

it is a reputable and objective government agency. 

Although the cores varied in thickness and in depth, geologists identified the Marcellus 

Shale stratum in several cores using data on the organic matter (carbon), sulfur, and uranium 

content of the samples. Table 1 below summarizes the results from four cores that tapped into 

the radioactive Marcellus formation. The depths at which the layer was found as well as the 

uranium measurements are presented. 

Location of the Core Depth of Sample (feet) Uranium Content (ppm) 

Allegheny Cty, PA 7342 – 7465 8.9 – 67.7 

Tomkins Cty, NY 1380 – 1420 25 – 53 

Livingston Cty, NY 543 – 576 16.6 – 83.7 

Knox Cty, OH 1027 – 1127 32.5 – 41.1 

Table 1. Uranium Content and Depth of Marcellus Shale in Four Cores 

The four cores were taken from different geographical locations, but the characteristics of 

the identified Marcellus shale layer, specifically the high uranium and carbon content, are 

consistent. 

To compare the uranium content in parts per million (weight) to radioactive concentration 

in picocuries per gram, we use the correspondence (HPS, 2007): 

2.97 ppm = 1 pCi/g U-238 

Using this relationship, the U-238 ranges up to 28 pCi/g, or 32 times background for radium-226, 

assuming U-238 and Ra-226 are in secular equilibrium, as it is in the Marcellus Shale formation. 

That is, the USGS measurements and the GAPI logs are consistent. This is our starting point for 

the concentrations of Ra-226 in the natural Marcellus Shale formation. The radium itself is 

found in the pore water of the Marcellus Shale formation, since radium, under the temperature, 

pressure and chemical conditions, is preferentially dissolved in the pore water. 

FATE AND TRANSPORT OF RADIOACTIVE MATERIALS 
If higher levels of radioactivity are present in the Marcellus shale formation, as shown by gamma 

logs, USGS measurements, and statements by DEC, where will this radioactivity appear in the 

aboveground environment and how will DEC regulate this radioactive waste? 

To discuss where uranium, radium and other radionclides enter the environment, we consider 

two components of natural gas development: well development and production. 

Well Development 

We are concerned about the horizontal, not the vertical, component of natural gas wells. As seen 

in Figure 5, fracking consists of pumping a fluid, proppants and chemicals under high pressure to 

Figure 5. Fracking 

create fractures along the horizontal region. I’m not going to discuss other chemicals that may 

contaminate properties, such as arsenic, mercury and hydrocarbons. The fracture zone may 

extend up to 200 foot radius from the horizontal bore. The bore itself may extend horizontally 

up to a mile. One 4,000-foot lateral wellbore undergoing hydraulic fracturing may require 

between 2.4 million and 7.8 million gallons of water. (NYDEC, 2009). During well 
development, rock cuttings are produced. These are separated from the drilling fluid by shakers, 

shown in Figure 6. 

Figure 6. Rock cutting shakers 

Rock Cuttings 

The drilling fluid itself may be partially recycled and the rock cuttings have been going to solid 

waste landfills. Radium is located in the water and not in the shale rock itself. But solid waste 

that goes to a solid waste landfill can be, according to NYS regulations, up to 20% water. An 

industry lab measured rock cuttings with a gamma detector; the rock cuttings were shown to be 

slightly radioactive. On the other hand, NYDEC, in their 2009 Draft Supplemental GEIS, 

reported radioactivity for two wells in Lebanon and Bath, NY, total radioactivity concentrations 

of 25.4 +/- 4.6 and 29.2 +/- 4.3 pCi/g, respectively, which is consistent with what we expect from 

the gamma logs and USGS findings. The EPA limits for radium in surface soil (EPA, 2011) are 

5 pCi/g in the top 15 cm, and 15 pCi/g below 15 cm. These rock cuttings, above EPA limits, 

should be disposed of in a licensed facility for handling radioactive materials, such as Energy 

Solutions in Clive, Utah. DEC and the Ohio EPA believe they have no jurisdiction over NORM, 

but if drilling fluid is recycled, the NORM is technologically enhanced. I’m not a lawyer, but it 

appears to me that these agencies do have jurisdiction over TENORM, if recycled drilling fluids 

are intermixed with rock cuttings. 

Flowback Water 
After a well is drilled, part of the hydraulic fracturing fluid flows back to the wellhead. This 

flowback water constitutes about 10 – 40% of the original pumped volume. (NYTimes, 2011) 

Since Marcellus shale is of marine origin, it contains high levels of salt and NORM which is 

dissolved in the fluid. (Cornell, 2010) DEC found 13 samples of flowback water from vertical 

Marcellus shale wells in Schuyler, Chemung and Chenango counties to contain radioactive 

concentrations as high as 267 times the limit for discharge into the environment and thousands of 

times the limit for drinking water. (Davies, 2009) Flowback water from horizontal drilling will 

be much more radioactive. If flowback water is fed to a water treatment plant, the radium needs 

to be removed, as we’ll discuss shortly. 

Well Production 

Once a natural gas well is producing, salt water or brine is brought up with the natural gas, and is 

separated out at the water gas separator. DEC has sampled brine for radium-226 and radium228. The results are shown in Table 2 below. 

Well Town County Ra-226 Ra-228 

Maxwell 1C Caton Steuben 7885 234 

Frost 2 Orange Schuyler 2647 782 

Carpenter 1 Troupsburg Steuben 5352 138 

Webster T1 Orange Schuyler 16030 912 

Calabro T1 Orange Schuyler 13510 929 

Schiavone 2 Reading Schuyler 15140 957 

WGI 11 Dix Schuyler 10160 1252 

Table 2. Radioactivity in Brine Water (pCi/L) 

The radium concentrations in brine are very high. While no one is drinking brine, just to 

compare these concentrations with drinking water standards, 5 pCi/L combined radium-226 and 

228. That is, the radium concentrations in brine range up to 3000 times safe drinking water 

limits. Under the proposed DEC regulations (NYDEC, 2010), a drill applicant must have a plan 

to deal with flowback water and brine, and that is where water treatment specialists enter the 

picture. A practice, which has since been suspended, is to spread brine, as a de-icing solution, on 

highways in New York State. 

Just to get a handle on the magnitude of the problem. If hydraulic fracturing were approved, 

DEC estimates 1600 drilling applications per year; each horizontal well will produce between 2.4 
million and 7.8 million gallons of flowback water. So we estimate 3.8 to 12.5 billion gallons of 

contaminated water per year that has to be treated. This is a small volume compared to the water 

usage in New York State, but this type of waste poses additional problems. 

In Pennsylvania, much of the 1.3 billion gallons of radioactively-contaminated water produced 

between 2007 and 2010 was sent to sewage treatment plants. Most sewage plants in the State are 

not required to monitor for radioactivity, so there are little data. According to sewage plant 

operators interviewed by the Times (NYTimes, 2011), these plants are not equipped to remove 

radioactive material. 

As a potential method of treating flowback water and brine, one can investigate the method of 

treating uranium mine waste water, which has high concentrations of radium. Here radium is 

precipitated with barium chloride to produce barium sulfate Ba(Ra)SO4. Radium is then a 

particulate that can be filtered. Water treatment plants may then meet SPDES permit limits, and 

the filters will have to be sent to a licensed landfill. Other methods include cation exchange 

softening, lime softening, and sorption onto MnO2. A physical process being proposed by Atela, 

Inc and Casella Waste Systems is distillation, low pressure evaporation. The sludge would then 

have to be disposed of in a licensed landfill. Volatiles from this process would have to be 

captured. It is not clear whether municipal water treatment plants can handle the magnitude of 

the radioactive waste problem posed by flowback water and brine, so that will be a challenge to 

water treatment professionals, such as you. 

Radium scale buildup in gas equipment. 

During production, radium dissolved in water, is brought to the surface. Scale, radium sulfate, 

plates out on production pipe surfaces. Scale also appears in water/gas separators, feeder lines 

and condensate tanks. As DEC states, a high concentration of scale will result in an elevated 

radiation exposure level at the pipe exterior surface. (NYDEC, 2011) The NYS Department of 

Health (DOH) proposes a radioactive materials license when exposure levels exceed 50 

microR/hr (μR/h). (NYDEC, 2012b) Our calculations show that the radium concentrations for 

an external dose rate of 50 μR/h are far higher than the EPA limit of 5 pCi/g. We have found 

that exposed workers have an increased risk of developing cancer. Workers at, and residents 

near, pipeyards that clean pipe scale will have an additional risk from inhaling radioactive dust. 

Based on our experience, the proposed DOH regulations are too lax, as we discuss below. 

For DEC and DOH to grasp the magnitude of the problem, we provide one example. At one 

natural gas well in Texas, 388 pipe joints were pulled after 5 years service. Exposure levels 

exceeded 50 μR/h in 55% of the 30 foot joints (max, 150 μR/h) 38% were < 50 μR/h and 7% 

were free of NORM. Similarly, hundreds of pipes at each gas well in New York and 

Pennsylvania will be contaminated with radium scale. If thousands of gas wells are drilled in 

New York State, how will DEC and DOH have the resources to regulate the industry and track 

these contaminated pipes? In our experience, oil and gas producing pipes with high external 

exposure levels have been “donated” to city governments for playgrounds in Texas, or to farmers 

for use in animal corrals in Texas and Kentucky. They have been cut up with oxyacetylene 

torches and welded to fit their use. In the process, children and farmers have been directly 
exposed to gamma, and inhaled radium. Workers at pipeyards that cleaned pipes have inhaled 

radium-contaminated dust and have developed cancer.

We find that direct gamma exposure levels of 50 μR/h are much too high. In order to determine 

the concentrations of Ra-226 and Ra-228 that correspond to a dose rate of 50 μR/hr, we 

employed the program MicroShield (Grove, 2008), a program used to estimate dose rates due to 

a specific external radiation source. 

As inputs to MicroShield, we assumed an outer pipe diameter of 4 inches (10.16 cm), a scale 

thickness of 0.2 cm, and a pipe wall thickness of 0.91 cm, as suggested by the US EPA EPA, 

1993b). We could also have used another standard pipe diameter, 2 7/8 inch. We assumed that 

each contaminated pipe is 30 feet long, and that radiation measurements had been taken at the 

center of the pipe, on contact with the outer pipe wall. From MicroShield, for a pipe with 

external gamma of 50 μR/h, we obtain a Ra-226 concentration in scale of 1,313.5 pCi/g, and a 

Ra-228 concentration in scale of 437.8 pCi/g that correspond to a dose rate of 50 μR/h. We 

assumed a 3 to 1 ratio of Ra-226 to Ra-228. 

As DEC and DOH are well aware, the EPA cleanup standard for total radium on soil is 5 pCi/g 

for the first 15 cm depth and 15 pCi/g 15 cm or more below the surface. Pipes, with external 

radiation 50 μR/h greatly exceed this standard. If these pipes, with NORM <50 μR/h are 

released for general use, they will be cut up and welded and the scale will be accessible. Ground 

contamination could easily exceed 5 pCi/g or 15 pCi/g. Though the 50 μR/h limit has been 

instituted in several States, in my opinion the DOH-suggested dose rate of 50 μR/h is much too 

high. 

While DEC and DOH intend to regulate joints with external radiation > 50 μR/h, in practical 

terms, it is not clear what the State agencies envisage will become of these radioactive pipes (and 

separators, feed lines and condensate tanks). Once the oil and gas industry begins production in 

New York State, this will be a major unresolved problem down the road. 

Radon in Natural Gas 

Yet another significant public health hazard associated with drilling for natural gas in the 

Marcellus Shale formation that should be seriously investigated by the New York State 

Department of Environmental Conservation (DEC) and other State agencies is the radon hazard. 

This hazard has the potential for large numbers of lung cancer among natural gas customers. 

This issue, which has been ignored in the DEC’s Draft Supplemental Environmental Impact 

Statement (NYDEC, 2011), must be addressed in a revised Impact Statement and before DEC 

issues any hydraulic fracturing drilling permits in the Marcellus shale. 

Unlike present sources for natural gas, located in Texas and Louisiana, the Marcellus Shale is 

considerably closer to New York consumers. In addition, the radioactive levels at the wellheads 

in New York are higher than the national average for natural gas wells throughout the United 

States. 
In a paper we recently submitted to a journal (RWMA, 2012), RWMA calculated the wellhead 

concentrations of radon in natural gas from Marcellus Shale, the time to transit to consumers, 

particularly New York City residents, and the potential health effects of releasing radon, 

especially in the smaller living quarters found in urban areas. 

It is well known that radon (radon-222) is present in natural gas (ATSDR, 1999) (NRC, 1988) 

and has been known since the early 1900’s (Gesell, 1975). Published reports by R. H. Johnson 

of the U.S. Environmental Protection Agency (Johnson, 1973) and C. V. Gogolak of the U.S. 

Department of Energy (Gogolak, 1980) address this issue in depth, as we discuss below. Radon 

is present in natural gas from Marcellus Shale at much higher concentrations than natural gas 

from wells in Louisiana and Texas. 

Since radon is a decay product of radium-226, to calculate radon levels it is necessary to know 

the concentrations of radium-226. Based on a USGS study (Leventhal, 1981) and gamma ray 

logs (also known as GAPI logs) that we have examined, the radium concentrations in the 

Marcellus Shale is 8 to 32 times background. This compares to an average radium-226 in surface 

soil in New York State of 0.81 picoCuries per gram (pCi/g). 

Using this range of radium concentrations and a simple Fortran program that simulates the 

production of radon in the well bore, and transit to the wellhead, we calculate a range of radon 

concentrations at the wellhead between 36.9 picoCuries per liter (pCi/L) to 2576 pCi/L. The 

maximum calculated concentration in Marcellus shale, 2576 pCi/L, is higher than the maximum 

concentrations found in the Panhandle region of Texas, 1450 pCi/L. (Johnson, 1973) (Gogolak, 

1980). 

These wellhead concentrations in Marcellus shale are up to 70 times the average in natural gas 

wells throughout the U.S. The average was calculated by R. H. Johnson of the U.S. 

Environmental Protection Agency in 1973 (pre-fracking) to be 37 pCi/L (Johnson, 1973) to a 

maximum of 1450 pCi/L. 

In addition, the distance to New York State apartments and homes from the Marcellus formation 

is 400 miles and sometimes less. This contrasts with the distance from the Gulf Coast and other 

formations, 1800 miles. At 10 mph movement in the pipeline, natural gas containing the 

radioactive gas, radon, which has a half-life of 3.8 days, will have three times the radon 

concentrations than natural gas originating at the Gulf Coast, everything else being equal, which 

it is not. 

Being an inert gas, radon will not be destroyed when natural gas is burned in a kitchen stove. 

We have examined published dilution factors and factored in numbers for average urban 

apartments where the dilution factor and the number of air exchanges per hour are less than those 

of non-urban dwellings. This analysis implies that the radon concentrations in New York City 

and urban apartments will be greater than the national average. 

We assume 11.9 million residents in New York State are affected. This figure is calculated in 

the following manner: Based on U.S. Department of Energy figures our calculations assume 4.4 
million gas stoves in New York State (EIA, 2009). This figure is multiplied by 2.69 persons per 

household to determine the number of residents affected: this number equals 11.9 million. 

We calculate the number of excess lung cancer deaths for New York State. Our results: the 

potential number of fatal lung cancer deaths due to radon in natural gas from the Marcellus shale 

range from 1,182 to 30,448. 

This is an additional number of lung cancer deaths due to radon from Marcellus Shale over 

deaths from natural radon already impacting New York State homes and their residents. 

The Draft Supplemental Environmental Impact Statement produced by the New York State 

Department of Environmental Conservation (NYDEC, 2011) needs to be revised to take into 

account this public health and environmental hazard. In the entire 1400 page statement there is 

only one sentence containing the word “radon” and no consideration of this significant public 

health hazard. 

Further, NYDEC needs to independently calculate and measure radon at the wellhead from the 

Marcellus Shale formation in presently operating wells before issuing horizontal hydraulic 

drilling permits in New York State. The presence of processing plants and storage must also be 

taken into account, and can serve to reduce the radon concentrations in natural gas delivered to 

consumers. The present rdsGEIS by DEC discusses none of these issues and should be 

rewritten. 

CONCLUSIONS 

Studies by the U.S. Geological Survey and gamma logs of drillers show radium concentrations 

up to 32 times background concentrations in the Marcellus shale formation. Brought to the 

surface in rock cuttings, drilling fluids, flowback water and brine, radium can enter the 

environment in several forms. During well development, rock cuttings and flowback water 

containing radium will be bought to the surface. Flowback water from horizontal hydraulic 

fracturing in the Marcellus formation has high concentrations of radium that must be disposed in 

a deep well or properly separated at a water treatment facility; the radioactive filters or sludges 

must go to a licensed landfill. During well production, radioactively-contaminated brine, up to 

3000 times safe drinking water limits, must also be treated or disposed in a deep well. Radiumcontaminated scale will form on the down well pipes as well as feeder lines and condensate tanks 

and these must be safely decontaminated; direct gamma from these pipes will increase the 

radiation dose to workers and the general public. Workers at pipeyards have developed cancer 

from direct gamma radiation and inhaling radioactive dust. The scale must be sent to a licensed 

disposal facility. Radioactive radon gas in natural gas from the Marcellus shale formation, much 

closer to the end use market than natural gas from Texas and Louisiana, will enter homes 

through kitchen stoves. Unless this natural gas is treated or held up, increased radon 

concentrations in homes and urban apartments will cause an increase in lung cancer rates. 
REFERENCES 

AAPG, Langhorne Smith, American Association of Petroleum Geologists 2010 National 

Conference, “Tectonic and Depositional Setting of Marcellus and Utica Black Shales,” 2010. 

ATSDR, Agency for Toxic Substances and Disease Registry, U.S. Department of Health and 

Human Services, Public Health Service, Toxicological Profile for Ionizing Radiation,

September 1999, http://www.atsdr.cdc.gov/toxprofiles/tp149.pdf (accessed February 23, 

2012). 

Cornell, 2010. “Gas Wells: Waste Management of Cuttings, Drilling Fluids, Hydrofrack 

Water and Produced Water.” Accessed on 24 March, 2010. 

<http://wri.eas.cornell.edu/gas_wells_waste.html> 

Davies, Peter J., 2009. “Radioactivity: A Description of its Nature, Dangers, Presence in the 

Marcellus Shale and Recommendations by the Town Of Dryden to The New York State 

Department of Environmental Conservation for Handling and Disposal of such 

Radioactive Materials.” Cornell University. 

<http://www.tcgasmap.org/media/Radioactivity%20from%20Gas%20Drilling%20SGEIS

%20Comments%20by%20Peter%20Davies.pdf>.2009 

Energy Information Administration, United States Department of Energy, “Residential Energy 

Consumption Survey (RECS), RECS Survey Data, 2009,” 

http://www.eia.gov/consumption/residential/data/2009/#undefined (accessed February 

23, 2012). 

EPA, 40 CFR 192.12, 2011

EPA, United Stated Environmental Protection Agency (US EPA), “A Preliminary Risk 

Assessment of Management and Disposal Options for Oil Field Wastes and Piping 

Contaminated with NORM in the State of Louisiana,” RAE-9232/1-1, Rev.1, Prepared by 

Rogers and Associates and S. Cohen and Associates Inc. 1993

Geology.com, 2008, http://geology.com/articles/marcellus-shale.shtml

Gesell, T.F., University of Texas Health Science Center at Houston, “Occupational Radiation 

Exposure due to 222Rn in Natural Gas and Natural Gas Products,” Health Physics,29, pp. 

681-687, 1975. 

Gogolak, C.V., Environmental Measurements Laboratory, United States Department of Energy, 

Review of 222Rn in Natural Gas Produced from Unconventional Sources, (DOE/EML385), 1980.

Grove Software Incorporated, MicroShield, Version 8.02, 2008
HPS, Health Physics Society, Relationship between mass and radioactivity, 

http://www.hps.org/publicinformation/ate/q6747.html, 2007. 

Hill, D.; Lombardi, T. E.; Martin, J., “Fractured Shale Gas Potential in New York,” TICORA 

Geosciences, Inc., Arvada, Colorado, USA, 2004. 

Johnson, R.H. et al., United States Environmental Protection Agency, Radiation Programs 

Office, Assessment of Potential Radiological Health Effects from Radon in Natural Gas, 

(EPA/520/73/004), 1973.

Leventhal, J.; Crock, J.; Malcolm, M., United States Department of the Interior, Geological 

Survey, Geochemistry of trace elements and uranium in Devonian shales of the 

Appalachian Basin, (Open File Report 81-778), 1981.

Myrick, T.; Berven, B.; Haywood, F., Oak Ridge National Laboratory, State Background 

Radiation Levels: Results of Measurements Taken During 1975-1979, (ORNL/TM-7343), 

1981. 

NRC, United States National Research Council, Health, Risks of Radon and Other Internally 

Deposited Alpha-Emitters: BEIR IV, 1988. 

NYDEC, New York Department of Environmental Conservation, “Draft Supplemental Generic 

Environmental Impact Statement on the Oil, Gas and Solution Mining Regulatory 

Program.” http://www.dec.ny.gov/energy/58440.html, 2009

NYDEC, New York Department of Environmental Conservation, 2010. Regulations: Chapter IV 

Quality Services. Accessed on 6 April, 2010. <http://www.dec.ny.gov/regs/2491.html>. 

NYDEC, New York Department of Environmental Conservation, Revised Draft Supplemental 

Generic Environmental Impact Statement on the Oil, Gas and Solution Mining 

Regulatory Program, 2011, http://www.dec.ny.gov/energy/75370.html (accessed 

February 23, 2012). p. 6-202 

NYSERDA, New York State Energy Research Development Authority, “Technical Consulting 

Reports Prepared In Support Of The Draft Supplemental Generic Environmental Impact 

Statement For Natural Gas Production In New York State,” by Alpha Geoscience, 

September 2009. 

NYTimes, New York Times, “Regulation Lax as Gas Wells’ Tainted Water Hits Rivers,” 

February 2011. 

RWMA, “Radon in Natural Gas from Marcellus Shale,” submitted to the journal, New Solutions, 

June 2012