United States
Environmental Protection
Agency
Air and Radiation
(6604J) •
402-R-93-050
September 1993
v>EPA EPA's Map of Radon Zones
NEW JERSEY
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EPA'S MAP OF RADON ZONES
NEW JERSEY
RADON DIVISION
OFFICE OF RADIATION AND INDOOR AIR
U.S. ENVIRONMENTAL PROTECTION AGENCY
SEPTEMBER, 1993
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ACKNOWLEDGEMENTS
This document was prepared by the U.S. Environmental Protection Agency's (EPA's)
• Office of Radiation and Indoor Air (ORIA) in conjunction with the U.S. Geological Survey
(USGS). Sharon W. White was the EPA project manager. Numerous other people in ORIA
were instrumental in the development of the Map of Radon Zones, including Lisa Ratcliff,
Kirk Maconaughey, R Thomas Peake, Dave Rowson, and Steve Page.
EPA would especially like to acknowledge the outstanding effort of the USGS
radon team -- Linda Gundersen, Randy Schumann, Jim Otton, Doug Owen, Russell
Dubiel, Kendell Dickinson, and Sandra Szarzi -- in developing the technical base for the
Map of Radon Zones.
ORIA would also like to recognize the'efforts of all the EP'A Regional Offices, in
coordinating the reviews with the State programs and the Association of American State
Geologists (AASG) for providing a liaison with the State geological surveys. In addition,
appreciation is expressed to all of the State radon programs and geological surveys for their
technical input and review of the Map of Radon Zones. , .
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TABLE OF CONTENTS
I. OVERVIEW
II. THE USGS/EPA RADON POTENTIAL
ASSESSMENTS:INTRODUCTION
III. REGION 2 GEOLOGIC RADON POTENTIAL
SUMMARY
V. PRELIMINARY GEOLOGIC RADQN POTENTIAL
ASSESSMENT OF NEW JERSEY
V. EPA'S MAP OF RADON ZONES - NEW JERSEY
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OVERVIEW
Sections 307 and 309 of the 1988. Indoor Radon Abatement Act (IRAA) direct EPA to
identify areas of the United States that have the potential to produce'elevated levels of radon.
EPA, .the U.S. Geological Survey (USGS), and the Association of American State Geologists
(AASG) have worked closely over the past several years to produce a series of maps and
documents which'address these directives. The EPA Map of Radon Zones is a compilation of
that work and fulfills the requirements of sections 307 and 309. of IRAA. The Map of Radon
Zones identifies, on a county-by-county basis, areas of the U.S. that have'the highest potential
for elevated indoor radon levels (greater than 4 pCi/L). !
The Map of Radon Zones is designed to assist national, State and-local governments
and organizations to target their radon program activities and resources. It is also intended to
help building code officials determine areas that are the highest priority for. adopting radon-
resistant building.practices. The Map of Radon Zones should not be .used to determine if
individual homes in any given area need to be tested for radon. EPA recommends that all •
homes be tested for radon, regardless of geographic location or the zone designation of
the county in which they are located.
This, document provides background information concerning the development of the
Map of Radon Zones.. It explains the purposes of the map, the approach for developing the
map (including the respective roles of EPA and USGS), ,the data sources used, the conclusions
and confidence levels developed for the prediction of radon potential, and the review process/.
that was conducted to finalize this effort. '
BACKGROUND
» ~* ' • - -'".-'
- . Radon (Rn222) is a colorless, odorless, radioactive gas: It comes from the natural
, decay of uranium that is found in nearly all soils. It typically moves through the ground to,
the air above and into homes and other buildings through cracks and openings in the
foundation. Any home, school or workplace may have a radon problem, regardless of
whether it is new or old, well-sealed or drafty,' or with or without a basement. Nearly one out
of every 15 homes in.the U.S. is estimated to have elevated annual'average levels of indoor
radon. ''•,-.• ,
Radon first gained national attention in early 1984, when extremely high levels of
indoor radon were found in areas of Pennsylvania, New Jersey, and New York, along the
Reading Prong-physiographic province. EPA established a Radon Program in 1985 to assist
States and homeowners in reducing their risk of lung cancer from indoor radon.
Since 1985, EPA and USGS have been working together to continually increase our
understanding of radon sources and the migration dynamics that, cause elevated indoor radon
levels., Early efforts resulted in the 1987 map entitled "Areas with Potentially High Radon
Levels." This map was based on limited geologic information only because few indoor radon
measurements were available at the time. The development of EPA's Map of Radon Zones
and its technical foundation, USGS' National Geologic Radon Province Map, has been based
on additional information from six years of the State/EPA Residential Radon Surveys,
independent State residential surveys, and continued expansion of geologic and geophysical
1 information, particularly the data from the National Uranium Resource Evaluation project.
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Purpose of the Map of Radon Zones
EPA's Map of Radon Zones (Figure 1) assigns each of the 3141 counties in the
United States to one of three zones:
o Zone 1 counties have a predicted average indoor screening level > than
4 pCi/L
o Zone 2 counties have a predicted average screening level > 2 pCi/L and
< 4 pCi/L
o Zone 3 counties have a predicted average screening level < 2 pCi/L
The Zone designations were determined by assessing five factors that are known to be
important indicators of radon potential: indoor radon measurements, geology, aerial
radioactivity, soil parameters, and foundation types.
The predictions of average screening levels in each of the Zones is an expression of
radon potential in the lowest liveable area of a structure. This map is unable to estimate
actual exposures to radon. EPA recommends methods for testing and fixing individual homes
based on an estimate of actual exposure to radon. For more information on testing and fixing
elevated radon levels in homes consult these EPA publications: A Citizen's Guide to Radon,
the Consumer's Guide to Radon Reduction and the Home Buyer's and Seller's Guide to
Radon.
EPA believes that States, local governments and other organizations can achieve
optimal risk reductions by targeting resources and program activities to high radon potential •
areas. Emphasizing targeted approaches (technical assistance, information and outreach
efforts, promotion of real estate mandates and policies and building codes, etc.) in such areas
addresses the greatest potential risks first. '
EPA also believes that the use of passive radon control systems in the construction of
new homes in Zone 1 counties, and the activation of those systems if necessitated by follow-
up testing, is a cost effective approach to achieving significant radon risk reduction.
The Map of Radon Zones and its supporting documentation establish no regulatory
requirements. Use of this map by State or local radon programs and building code officials is
voluntary. The information presented on the Map of Radon Zones and in the supporting
documentation is not applicable to radon in water.
Development of the Map of Radon Zones ••
The technical foundation for the Map of Radon Zones is the USGS Geologic Radon
Province Map. In order to examine the radon potential for the United States, the USGS
began by identifying approximately 360 separate geologic provinces for the U.S. The
provinces are shown on the .USGS Geologic Radon Province Map (Figure -2). Each of the
geologic provinces was evaluated by examining the available data for that area: indoor radon
measurements, geology, aerial radioactivity, soil parameters, and foundation types. As stated
previously, these five factors are considered to be of basic importance in assessing radon
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potential and some data are available for each of.these factors in every geologic province. The
province boundaries do not coincide with political borders (county and state) but define areas
of general radon potential The five factors were assigned numerical values based on an
/assessment of their respective contribution to radon potential, and a confidence, level was ,.
assigned to each contributing variable. The approach used by USGS. to 'estimate the radon
potential for each province is described in Part II of this document.
' EPA subsequently developed the Map of Radon Zones by extrapolating from the
province level to the county level so that all counties in the U.S. were assigned to one of
three radon zones. EPA assigned each county to a given zone based on its provincial radon
potential. For example, if a county is. located within a geologic province that has a- predicted
average screening level greater than 4 pGi/L, it was assigned to Zone 1. Likewise, counties
located in provinces with predicted average screening levels > 2 pCi/L and < 4 pCi/L, and
less than 2 pCi/L, were assigned to Zones 2 and 3, respectively. /
If the boundaries of a county fall in more than one geologic province, the county was
assigned to a'zone based on the predicted radon potential of the province in which most of
the area lies. For, example, if three different provinces cross through a given county, the
county was assigned to the zone representing the radon potential of the province containing
most of the county's land area. (In this case, it is not technically correct to say that the
predicted average screening level applies to the entire county since'the county falls in
multiple provinces with differing radon potentials.) .
Figures 3 and 4 demonstrate an example of.how EPA extrapolated the county zone .
designations for Nebraska from the USGS geologic province map for .the State. As figure 3 .'
shows, USGS has identified 5 geologic provinces for Nebraska. Most of the counties are . .'.
extrapolated "straight" from their corresponding provinces, but there are counties "partitioned"
by several provinces .-- for example, Lincoln County. Although Lincoln county falls in -
multiple provinces, it was assigned to Zone 3 because most of its area falls in the province
with the lowest radon pqtential. ' . r ' . ,
It is important to note that EPA's extrapolation from the province level to the
county lever may mask significant "highs" and "lows" within specific counties. In other
words, within-county variations in radon potential are not shown on the Map of Radon
Zones. EPA recommends that users who may need to address specific within-county
variations in radon potential (elg., local government officials considering the
implementation of radon-resistant construction codes) consult USGS1 Geologic Radon
Province Map and the State chapters provided with this map for more detailed
information, as well as any locally available data.
• . ' A , .• * ' , - ' .
Map Validation
The Map of Radon Zones is intended to represent a preliminary assessment of radon
potential for the entire United States. The factors that are used in this effort --indoor radon
data, geology, aerial radioactivity; soils, and foundation type -- are basic indicators for radon
potential. It is important to note, however, that the map's county zone designations are not
"statistically valid" predictions due to the nature of the data available for these 5 factors at the
, county level. In order to validate the map in light of this lack of statistical confidence, EPA
conducted a number of analyses. These analyses have helped EPA to identify the best
situations in which to apply the map, .and its limitations. ,
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Figure 3
Geologic Radon Potential Provinces for Nebraska
Lincoln County
Bijk Uoicntc Lo»
Figure 4
NEBRASKA - EPA Map of Radon Zones
Lincoln County
Zoae 1 la it 2 Zone 3
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One such analysis involved comparing county zone designations to indoor radon
measurements from the State/EPA Residential Radon Surveys (SRRS). Screening averages
for counties with at least 100 measurements were compared to the. counties' predicted radon
potential as indicated by the Map of Radon Zones. EPA found that 72% of the county
' screening ^averages were correctly reflected by the appropriate zone designations on the Map,
In all other cases, they only differed by 1 zone.
Another accuracy analysis used the annual average data from the National Residential
.Radon Survey (NRRS). The NRRS indicated that approximately 6 .million homes in the
United States have annual averages greater than or equal to 4 pCi/L. By cross checking the
county location of the approximately 5,700 homes which participated in the survey, their,
radon measurements, and the zone designations for these counties, EPA found that
approximately 3.8 million homes of the 5.4 million homes with radon levels greater than or
equal to 4 pCi/L will be found in counties designated as Zone 1. A random sampling of an
equal number of counties would have only found :approximately 1.8 million homes greater
than 4 pCi/L. In other words, this analysis indicated that the map approach is three times
more efficient at identifying high radon areas than random selection of zone designations,
Together, these analyses show that the approach EPA used to develop the Map of
Radpn Zones is a reasonable one.. In addition, the Agency's.confidence is enhanced.by results.-
of the extensive State review process -- the map generally agrees with the States'1 knowledge
of and experience in their own jurisdictions. However, the accuracy analyses highlight two
important points: the fact that elevated levels will be. found in Zones 2 and 3, and that there
will be significant numbers of homes with lower indoor radon levels in all of the Zones. For
these reasons,, users of the Map of Radon Zones need to supplement the Map with locally
available data whenever possible. Although ajl known "hot spots", i.e., localized areas of •
' consistently elevated levels, are discussed in the State-
specific chapters, accurately defining the boundaries of the "hot spots" on this scale of map is
not possible at this time. Also, unknown "hot spots" do exist. . _- ,,
The Map of Radon Zones is intended to be a starting point for characterizing radon
potential because our knowledge of radon sources and transport is always growing. Although
this effort represents the best data available at this time, EPA will continue to study these
parameters and others such as house construction, ventilation features and meteorology factors
in order to better characterize the presence of radon in U.S homes, especially in high risk
areas. These efforts will eventually assist EPA.in refining and revising the conclusions of the
Map of Radon Zones. And although this map is most appropriately used as a targeting tool
by the aforementioned audiences ~ the Agency encourages all residents to test their homes
for radon, regardless of geographic location or the zone designation of the county in
which they live. Similarly, the Map of Radon Zones should not to be used in lieu of
testing during real estate transactions.
Review Process , '
The Map of Radon Zones has undergone extensive review within EPA and outside the
Agency. The Association of American State Geologists (AASG) played an integral role in
.• this review process. The AASG individual State geologists have reviewed their State-specific
information, the USGS Geologic Radon Province Map, and other materials for their geologic
content and consistency. , ' , .••';-.
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In addition to each State geologist providing technical comments, the State radon
offices were asked to comment on their respective States' radon potential evaluations. In
particular, the States were asked to evaluate the data used to assign their counties to specific
zones. EPA and USGS worked with the States to resolve any issues concerning county zone
designations. In a few cases, States have requested changes in county zone designations. The
requests were based on additional data from the State on geology, indoor radon
measurements, population, etc. Upon reviewing the data submitted by the States, EPA did
make some changes in zone designations. These changes, which do not strictly follow the
methodology outlined in this document, are discussed in the respective State chapters.
EPA encourages the States and counties to conduct further research and data collection
efforts to refine the Map of Radon Zones. EPA would like to be kept informed of any
changes the States, counties, or others make to the maps. Updates and revisions will be
handled in a similar fashion to the way the map was developed. States should notify EPA of
any proposed changes by forwarding the changes through the Regional EPA offices that are
listed in-Part II. Depending on the amount of new information that is presented, EPA will
consider updating this map periodically. The State radon programs should initiate proper
notification of the appropriate State officials when the Map of Radon Zones is released and
when revisions or updates are made by the State or EPA.
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THE USGS/EPA RADON POTENTIAL ASSESSMENTS: AN INTRODUCTION
. • . •" ' '.- by ' ', < .
Linda C.S. Gundersen and R. Randall Schumann
• U.S. Geological Surrey
arid •
Sharon W. White
U.S. Environmental Protection Agency
BACKGROUND
The Indoor Radon Abatement Act of 1988 (15 U.S.C. 2661-2671) directed the U.S.
Environmental Protection Agency (EPA) to identify areas of the Unite'd States that have,the
potential to produce harmful levels of indoor radon. These characterizations-were to be based •
on both geological data and on indoor radon levels in homes and other .structures. The EPA
also was directed to develop model standards and techniques for new building construction
that would provide adequate prevention or mitigation of radon entry. As part of an
Interagency Agreement between the EPA and the U.S. Geological Survey, (USGS), the USGS
has prepared radon potential estimates for the United States. This report is one of ten
booklets that document this effort. The purpose and intended use of these reports is to help
identify areas where states Can target their radon program resources, to provide guidance in.
selecting the most appropriate building code options for areas, and to provide general
information on radon and geology for each state for federal, state, and municipal officials
dealing with radon issues. These reports, are nor intended to be used as a substitute for •
indoor radon testing, and they cannot and should not be used to estimate or predict the
indoor radon concentrations of individual homes, building sites, or housing tracts. Elevated
levels of indoor radon have been found in every State, and EPA recommends that all homes
be tested for indoor radon. * .....'•
Booklets detailing the radon potential assessment for the U.S. have been developed for
each State. USGS geologists ate the authors of the geologic radon .potential booklets. Each
booklet consists of several components, the first being an overview to the mapping project ,
(Part I), this introduction to the USGS assessment (Part II), including a general discussion of
radon (occurrence; transport, etc.), arid details concerning the types of data used. The third
component is a summary chapter outlining the general geology and geologic radon potential
of the'EPA Region (Part III). The fourth component is an individual chapter for'each state
(Part JV). Each state chapter discusses the state's specific geographic setting, soils, geologic
setting, geologic radon potential, indoor radon data, and a summary outlining the radon
potential rankings of geologic areas in the state. A variety of maps are presented in each
chapter—geologic, geographic, population, soils, aerial radioactivity, and indoor radon data by
county. Finally, the booklets contain EPA's map of radon zones for each state and an
accompanying description (Part V). ,
Because of constraints on the scales of maps presented in these reports and because the
smallest units used,to present the indoor radon data are counties, some generalizations have
been made in order to estimate the.radon potential of each area. Variations in geology, soil
characteristics, climatic factors, homeowner lifestyles, and other factors "that influence radon
concentrations can be quite large within any particular geologic area, so these reports cannot
be used to estimate or predict the indoor radon concentrations of individual homes or housing
' II-l Reprinted from USGS Open-File Report 93-292
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tracts. Within any area of a given geologic radon potential ranking, there are likely to be
areas where the radon potential is lower or higher than that assigned to the area as a whole,
especially in larger areas such as the large counties in some western states.
In each state chapter, references to additional reports related to radon are listed for the
. at., and the reader-is urged to consult these reports for more detc.iled informa''on. In most
cases the best sources of information on radon for specific areas are state and local
departments of health, state departments responsible for nuclear safety or environmental
protection, and U.S. EPA regional offices. More detailed information on state or local
geology may be obtained from the state geological surveys. Addresses and telephone
numbers of state radon contacts, geological surveys, and EPA regional offices are listed in
Appendix C at the end of this chapter.
RADON GENERATION AND TRANSPORT IN SOILS
Radon (2"Rn) is produced from the radioactive decay of radium (~6Ra), which is, in turn,
a product of the decay of uranium (338U) (fig. 1). The half-life of ~3Rn is 3.825 days. Other
isotopes of radon occur naturally, but, with the exception of tho'ron (~°Rn), which occurs in
concentrations high enough to be of concern in a few localized areas, they are less important
in terms of indoor radon risk because of their extremely short half-lives and less common
occurrence. In general, the concentration and mobility of radon in soil are dependent on
several factors, the most important of which are the soil's radium content and distribution,
porosity, permeability to gas movement, and moisture content. These characteristics are, in
turn, determined by the soil's parent-material composition, climate, and the soil's age 6r
maturity. If parent-material composition, climate, vegetation, age of the soil, and topography
are known, the physical and chemical properties of a soil in a given area can be predicted.
As soils form, they develop distinct layers, or horizons, that are cumulatively called the
soil profile. The A horizon is a surface or near-surface horizon containing a relative
abundance of organic matter but dominated by mineral matter. Some soils contain an E
horizon, directly below the A horizon, that is generally characterized by loss of clays, iron, or
aluminum, and has a characteristically lighter color than the A horizon. The B horizon
underlies the A or E horizon. Important characteristics of B horizons include accumulation of
clays, iron oxides, calcium carbonate or other soluble salts, and organic matter complexes. In
drier environments, a horizon may exist within or below the B horizon that is dominated by
calcium carbonate, often called caliche or calcrete. This carbonate-cemented horizon is
designated the K horizon in modern soil classification schemes. The C horizon underlies the,
B (or K) and is a zone of weathered parent material that does not exhibit characteristics of A
or B horizons; that is, it is generally not a zone of leaching or accumulation. In soils formed
in place from the underlying bedrock, the C horizon is a zone of unconsolidated, weathered
bedrock overlying the unweathered bedrock.
The shape and orientation of soil particles (soil structure) control permeability and affect
water movement in the soil. Soils with blocky or granular structure have roughly equivalent
permeabilities in the horizontal and vertical directions, and air and water can infiltrate the soil
relatively easily. However, in soils with platy structure, horizontal permeability is rr.v.ch
greater than vertical permeability, and air and moisture infiltration is generally slow. Soils
with prismatic or columnar structure have dominantly vertical permeability. Platy and
prismatic structures form in soils with high clay contents. In soils with shrink-swell clays, air
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and moisture infiltration rates and depth of wetting may be limited when the cracks in the
surface soil layers swell shut. Clay-rich B horizons, particularly those with massive or platy
structure, can form a capping layer that impedes the escape of soil gas to the surface
(Schumann and others, 1992). However, the shrinkage of clays can act to open or widen
cracks upon drying, thus increasing the soil's permeability to gas flow during drier periods.
Radon transport in soils occurs by two processes: (1) diffusion and (2) flow (Tanner,
1964). Diffusion is the process whereby radon atoms move from areas of higher
concentration to areas of lower concentration in response to a concentration gradient. Flow is
the process by which soil air moves through soil pores in response-to differences in pressure
within the soil or between the soil and the atmosphere, carrying the radon atoms along with it.
Diffusion is the dominant radon transport process in soils of low permeability, whereas flow
tends to dominate in highly permeable soils (Sextro and others, 1987). 'In low-permeability
soils, much of the radon may decay before it is able to enter a building because its transport
rate is reduced. Conversely, highly permeable soils, even those that are relatively low in
radium, such as those derived from some types of glacial deposits, have been associated with
high indoor radon levels in Europe and in the northern United States (Akerblom and others,
1984; Kunz and others, 1989; Sextro and others, 1987). In areas of karst topography formed
in carbonate rock (limestone or dolomite) environments, solution cavities and fissures can
increase soil permeability at depth by providing additional pathways for gas flow.
Not all radium contained in soil grains and grain coatings will result in mobile radon
when the radium decays. Depending on where the. radium is distributed in the soil, many of
the radon atoms may remain imbedded in the soil grain containing the parent radium atom, or
become imbedded in adjacent soil grains. The portion of radium that releases radon into the
pores and fractures of rocks and soils is called the emanating fraction. When a radium atom
decays to radon, the energy generated is strong enough to send the radon atom a distance of
about 40 nanometers (1 nm = 10'9 meters), or about 2xlO:6 inches—this is known as alpha
recoil (Tanner, 1980). Moisture in the soil lessens the chance of a recoiling radon atom
becoming imbedded in an adjacent grain. Because water is more dense than air,, a radon atom
will travel a shorter distance in a water-filled pore than in an air-filled pore, thus increasing
the likelihood that the radon atom will remain in the pore space. Intermediate moisture levels
enhance radon emanation but do not significantly affect permeability. However, high
moisture levels can significantly decrease the gas permeability of the soil and impede radon
movement through the soil.
Concentrations of radon in soils are generally many times higher than those inside of
buildings, ranging from tens of pCi/L to more than'100,000 pCi/L, but typically in the range
of hundreds to low thousands of pCi/L. Soil-gas radon concentrations can vary in response to
variations in climate and weather on hourly, daily, or seasonal time scales. Schumann and
others (1992) and,Rose and others (1988) recorded order-of-magnitude variations in soil-gas
radon concentrations between seasons in Colorado and Pennsylvania. The most important
factors appear to be (1) soil moisture conditions, which are controlled in large part by
precipitation; (2) barometric pressure; and (3) temperature. Washington and Rose (1990)
suggest that temperature-controlled partitioning of radon between water and gas in soil pores
also has a significant-influence on the amount of mobile radon in soil gas.
Homes in hilly limestone regions of the southern Appalachians were found to have higher
indoor radon concentrations during the summer than in the winter. A suggested cause for this
phenomenon involves temperature/pressure-driven flow of radon-laden air from subsurface
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solution cavities in the carbonate rock into houses. As warm air enters solution cavities that
are higher on the hillslope than the homes, it cools and settles, pushing radon-laden air from
lower in the cave or cavity system into structures on the hillslope (Gammage and others,
1993). In contrast, homes built over caves having openings situated,below the level 'of the
home had higher indoor radon levels in the' winteij- caused by cooler outside air entering the
cave, driving radon-laden air into cracks and solution cavities in the rock and soil, and
ultimately, into homes (Gammage and others, 1993).
RADON ENTRY INTO BUILDINGS
A driving force (reduced atmospheric pressure in the house relative to the soil,, producing
a.pressure gradient) and entry points must exist for radon to enter a building from the soil.
The negative pressure caused by furnace combustion^ ventilation devices, and the stack effect
(the rising and escape of warm air from the upper floors of the building, causing a
temperature and pressure gradient within the structure) during cold winter months are
common driving forces. Cracks and other penetrations through building foundations, sump
holes, and slab-to-foundation wall joints are common entry points.
Radon levels in the basement are generally higher than those on the main floor or upper
floors of most structures. Homes with basements generally provide more entry points for
radon, commonly have a m.ore pronounced stack effect,.and typically have lower air pressure
relative to the surrounding soil than nonbasement homes. The term "nonbasement" applies, to .
slab-on-grade or crawl space construction.
METHODS AND SOURCES OF DATA , ,
The assessments of radon potential in the booklets that follow this introduction were
made using five main types of data: (1) geologic (lithologic); (2) aerial radiometric; (3) soil
characteristics, including soil moisture, permeability, and drainage characteristics; (4) indoor
radon data; and (5) building architecture (specifically, whether homes in each area, are built
Slab-on-grade or have abasement or crawl space).- These five factors were evaluated and •
integrated to produce,estimates of radon potential. Field measurements of soil-gas radon or
-soil radioactivity were hot used except where such data were available in existing, published
reports of local field, studies. Where applicable, such field studies are described in the
individual state chapters. . " •
GEOLOGIC DATA . . ; . . ' . "
f ' ' • ' ' ..'..'.
The types and distribution of lithologic units and other geologic features in an
assessment area are of primary importance in determining radon potential." Rock types that
are most likely to cause indoor radon problems include carbonaceous black shales, glauconite-
bearing. sandstones, certain kinds of fluvial sandstones and fluvial sediments, phosphorites,
chalk, karst-producing carbonate rocks, certain kinds of glacial deposits, bauxite, uranium-rich
granitic rocks, metamorphic rocks of.granitic composition, silica-rich volcanic rocks, many
sheared or faulted i;ocks, some coals, and certain kinds of contact metamorphosed rocks.
Rock types least likely to cause radon problems include marine quartz sands, non-
• carbonaceous shales and siltstones, certain kinds of clays, silica-poor metamorphic and
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igneous rocks, and basalts. Exceptions exist within these general lithologic groups because of
the occurrence of localized uranium deposits, commonly of the hydrothermal type in
crystalline rocks or the "roll-front" type in sedimentary rocks. Uranium and radium are
commonly sited in heavy minerals, iron-oxide coatings on rock and soil grains, and organic
materials in soils and sediments. Less common arc uranium associated with phosphate and
carbonate complexes in rocks and soils, and uranium minerals.
Although many cases of elevated indoor radon levels can be traced to high radium and
(or) uranium concentrations in parent rocks, some structural features, most notably faults and
shear zones, have been_identified as sites of localized uranium concentrations (Deffeyes and
MacGregor, 1980) and have been associated with some of the highest reported indoor radon
levels (Gundersen, 1991). The two highest known indoor radon occurrences are associated
with sheared fault zones in Boyertown, Pennsylvania (Gundersen and others, 1988a; Smith
and others, 1987), and in Clinton, New Jersey (Henry and others, 1991; Muessig and Bell,
1988). , ' •
NURE AERIAL RADIOMETRIC DATA
Aerial radiometric data are used to quantify the radioactivity of rocks and soils.
Equivalent uranium (eU) data provide an estimate of the surficial concentrations of radon
parent materials (uranium, radium) in rocks and soils. Equivalent uranium is calculated from
the counts received by a gamma-ray detector from the 1.76 MeV (mega-electron volts) .
emission energy corresponding to bismuth-214 (2I4Bi), with the assumption that uranium and .
its decay products are in secular equilibrium. Equivalent uranium is expressed in units of
parts per million (ppm). Gamma radioactivity also may be expressed in terms of a radium •
activity; 3 ppm eU corresponds to approximately 1 picocurie per gram (pCi/g) of radium-226.
Although radon is highly mobile in soil and its concentration is affected by meteorological
conditions (Kovach, 1945; Klusman and Jaacks, 1987; Schery and others, 1984; Schumann
and others, 1992), statistical correlations between average soil-gas radon concentrations and
average eU values for a wide variety of soils have been documented (Gundersen and others,
1988a, 1988b; Schumann and Owen, 1988). Aerial radiometric data can provide an estimate
of radon source strength over a region, but the amount of radon that is able to enter a home
from the soil is dependent on several local factors, including soil structure, grain size
distribution, moisture content, and permeability, as well as type of house construction and its
structural condition.
The aerial radiometric data used for these characterizations were collected as part of the
Department of Energy National Uranium Resource Evaluation (NURE) program of the 1970s
and early 1980s. The purpose of the NURE program was to identify and describe areas in the
United States having potential-uranium resources (U.S. Department of Energy, 1976). The
NURE aerial radiometric data were collected by aircraft in which a gamma-ray spectrometer
was mounted, flying approximately 122 m (400 ft) above the ground surface. The equivalent
uranium maps presented in the state chapters were generated from reprocessed NURE data in
which smoothing, filtering, recalibrating, and matching of adjacent quadrangle data sets were
performed to compensate for background, altitude, calibration, and other types of errors and
inconsistencies in the original data set (Duval and others, 1989). The data were then gridded
and contoured to produce maps of eU with a pixel size corresponding to approximately 2.5 x
2.5 km (1.6 x 1.6 mi).
II-6 Reprinted from USGS Open-File Report 93-292
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FLIGHT LINE SPACING 0F SUK£ AERI AL SURVEYS
2 KM (I MILE)
5 KM (3 MILES)
2 k 5 K«
10 KM (fi U1LES)
5 t 10 KM
NO DiTA , ,
Figure 2. Nominal flightline spacings for NUKE aerial gamma-ray surveys covering the
contiguous United States (from Duval and others, 1990). Rectangles represent I°x2° quadrangles.
-------
Figure 2 is an index map of NURE 1° x 2° quadrangles showing the flight-line spacing
for each quadrangle. In general, the more closely spaced the flightlines are, the more area
was covered by the aerial gamma survey, and thus, more detail is available in the data set.
For an altitude of 400 ft above the ground surface and with primary flightline spacing
typically between 3 and 6 miles, less than 10 percent of the ground surface of the United
States was actually measured by the airborne gamma-ray detectors (Duval and others, 1989),
although some areas had better coverage than others due to the differences in flight-line
spacing between areas (fig. 2). This suggests that some localized uranium anomalies may not
have been detected by the aerial surveys, but the good correlations of eU patterns with
geologic outcrop patterns indicate that, at relatively small scales (approximately 1:1,000,000
or smaller) the National eU map (Duval and others, 1989) gives reasonably good estimates of
average surface uranium concentrations and thus can assist in the prediction of radon potential
of rocks and soils, especially when augmented with additional geologic and soil data.
The shallow (20-30 cm) depth of investigation of gamma-ray spectrometers, either
ground-based or airborne (Duval and others, 1971; Durrance, 1986), suggests that gamma-ray
data may sometimes underestimate the radon-source strength in soils in which some of the
radionuclides in the near-surface soil layers have been transported downward through the soil
profile. In such cases the concentration of radioactive minerals in the A horizon would be
lower than in the B horizon, where such minerals are typically concentrated. The
concentration of radionuclides in the C horizon'and below may be relatively unaffected by
surface solution processes. Under these conditions the surface gamma-ray signal may indicate
a lower radon source concentration than actually exists in the deeper soil layers, which are
most likely to affect radon levels in structures with basements. The redistribution of •
radionuclides in soil profiles is dependent on a combination of climatic, geologic, and
geochemical factors. There is reason to believe that correlations of eU with actual soil
radium and uranium concentrations at a depth relevant to radon entry into structures may be
regionally variable (Duval, 1989; Schumann and Gund'ersen, 1991). Given sufficient
understanding of the factors cited above, these regional differences may be predictable.
SOIL SURVEY DATA
Soil surveys prepared by the U.S. Soil Conservation Service (SCS) provide data on soil
characteristics, including soil-cover thickness, grain-size distribution, permeability, shrink-
swell potential, vegetative cover, generalized groundwater characteristics, and land use. The
reports are available in county formats and State summaries. The county reports typically
contain both generalized and detailed maps of soils in the area.
Because of time and map-scale constraints, it was impractical to examine county soil
reports for each county in the United States, so more generalized summaries at appropriate
scales were used where available. For State or regional-scale radon .characterizations, soil
maps were compared to geologic maps of the area, and the soil descriptions, shrink-swell
potential, drainage characteristics, depth to seasonal high water table, permeability, and other
relevant characteristics of each soil group noted. Technical soil terms used in soil surveys are
generally complex; however, a good summary of soil engineering terms and the national
distribution of technical soil types is the "Soils" sheet of the National Atlas (U.S. Department
of Agriculture, 1987).
II-8 Reprinted from USGS Open-File Report 93-292
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N Soil permeability is commonly expressed in SCS soil surveys in terms of the speed, in
inches per hour (in/hr), at which water soaks into the soil, as measured in a soil percolation
test. Although in/hr are not truly units of permeability, these units are in widespread use and
are referred to as "permeability" in.SCS soil,surveys. The permeabilities--listed in the SCS
surveys are for water; but they generally correlate well with gas permeability. Because data
on gas permeability of soils is extremely limited, data on permeability-to'water, is used as a
substitute except in cases in which excessive soil moisture is known to exist. Water iri soil
pores inhibits gas transport, so the amount of radon available to a home is effectively reduced
by a high water table. Areas likely to have high water tables'include river valleys, coastal
areas, and some areas overlain by deposits of glacial origin (for example, loess).
s'oil permeabilities greater than 6.-0 in/hr may be considered high, and permeabilities less
than 0.6 in/hr may be considered low in terms of soil-gas transport. Soils with low
permeability may" generally be considered to have a lower radon potential than more
.permeable soils with similar radium concentrations.' Many well-developed soils contain a
clay-rich B horizon that may impede vertical soil gas transport. Radon generated below this
horizon cannot readily escape to the surface, so it would instead tend to move laterally,
especially under the influence of a negative pressure exerted by'a building.
Shrink-swell potential is an indicator of the abundance of smectitic (swelling) clays'in a
soil. Soils with a high shrink-swell potential may cause building foundations to crack,
creating pathways for radon entry into the structure. During dry periods, desiccation cracks in ;
shrink-swell soils provide additional pathways for soil-gas transport and effectively increase .
the gas permeability of the soil. Soil permeability data,and soil profile data thus provide
important information for regional radon assessments.
INDOOR RADON DATA
Two major sources of indoor radon data were used. The first and largest source of data is
from the State/EPA Residential Radon Survey (Ronca-Battista arid others, 1988; Dziuban and
others, 1990). Forty-two states completed EPA-sponsored indoor radon surveys between 1986
and 1992 (fig. 3). The State/EPA Residential Radon Surveys were designed to-be
comprehensive and statistically significant at the state level, and were subjected to high levels
of quality assurance and control. The surveys collected screening indoor radon measurements,
defined as 2-7 day measurements using charcoal canister radon detectors placed in the lowest
livable area of the home. The target population for the surveys included owner-occupied
single family, detached housing units (White and others, 1989), although attached structures
such as duplexesrtownhouses, or condominiums were included in some of the surveys if they
met the other criteria and had contact with the ground surface. Participants were selected
randomly from, telephone-directory listings.: In total, approximately 60,000 homes were tested
in the State/EPA surveys: - , , ....
The second source of indoor radon data comes from residential surveys that have been
conducted in a specific state or region of the country (e.g. independent state surveys or utility
company surveys). Several states, including Delaware, Florida, Illinois, New Hampshire, New
Jersey, New York, Oregon, and Utah, have conducted their own surveys of indoor radon. The
' quality and design of a state or other independent survey are discussed and referenced where
the data are used. . . . > .
11-9'" Reprinted from USGS Open-File Report 93-292
-------
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' Data for only those counties with five or more measurements are shown in the indoor,
radon maps in the state chapters, although data for all 'counties with a nonzero number of
measurements are listed in the indoor radon data tables in each state chapter. In total, indoor
radon data from more than 100,000 homes nationwide were used in the compilation of these
assessments. Radon data from State or -regional inciooi radon surveys, public health
organizations, or other sources are discussed in addition to the primary data sources where
they are available. .Nearly .all of the data used in these evaluations represent short-term (2-7 ..
day) screening measurements from the lowest livable space of the homes. Specific details
concerning the nature and use of indoor radon data sets other than the State/EPA Residential
Radon. Survey are discussed in the individual State chapters.
RADON.INDEX AND CONFIDENCE INDEX ' '
• Many of the geologic methods used to evaluate an area for radon potential require
subjective opinions based on the professional judgment and experience of the individual
geologist. The evaluations are nevertheless based on established scientific principles that are
universally applicable to any geographic area or geologic setting. This section describes the
methods and conceptual framework used by the U.S. Geological Survey to evaluate,areas for
radon potential based on the five factors discussed in the previous sections. The scheme is
divided into two basic parts, a Radon Index (RI), used 'to rank the general radon potential of
the area, and the Confidence Index (CI), used to express the level of confidence in the
prediction based on the quantity and quality of the data used to make the determination. This
scheme works best if the areas to be evaluated are delineated by geologically-based
•boundaries (geologic provinces) rather than political ones (state/county boundaries) in which
the geology may vary across the area. • ' '.'•.'•'
Radon Index. Table 1 presents the Radon Index (RI) matrix. The five factors—indoor
radon data, geology, aerial radioactivity, soil parameters, and house foundation type—were
quantitatively .ranked (using, a point value of 1, 2, or 3) for their respective contribution to . _
radon.potential in a given area. At least some data for the 5 factors are consistently available
,for every geologic province. Because each of these main factors encompass a wide variety of
complex and variable components, the geologists performing the evaluation relied heavily on
their professional judgment and experience in assigning point values to each category and in
determining the overall radon potential ranking. Background information on these factors is
discussed in moTe detail in 'the preceding sections of this introduction.. •
Indoor radon was evaluated using unweighted arithmetic means of the indoor radon data
for each geologic area to be assessed. Other expressions of indoor radon levels in an area
also could have been' used, such as weighted averages or annual averages, but these types of
data were not consistently available for the entire United States at the time of this writing, or
the schemes were not considered sufficient to provide a means of consistent comparison
across all areas. For this report, charcoal-canister screening measurement data from the
State/EPA Residential Radon Surveys and other carefully selected sources were used, as
described in the preceding section. To maintain consistency, other indoor radon data sets
(vendor, state, or other data) were not considered in scoring the indoor radon factor of the
Radon Index if they were not randomly sampled or could not be statistically combined with
the primary indoor radon-data sets. However, these additional radon data sets can provide a
means to further refine correlations between geologic factors and radon potential, so they are
11-11 Reprinted from USGS Open-File Report 93-292
-------
TABLE 1. RADON INDEX MATRIX, "ppm eU" indicates parts per million of equivalent
uranium, as indicated by NURE aerial radiometric data. See text discussion for details.
INCREASING RADON POTENTIAL
FACTOR
INDOOR RADON (average)
AERIAL RADIO ACTIVITY
GEOLOGY*
SOIL PERMEABILITY
ARCHITECTURE TYPE
POINT VALUE
1.
<2pCi/L
< 1.5 ppm eU
negative
low
mostly slab
2
2-4pCi/L
1.5 - 2.5 ppm eU
• variable
moderate
mixed
' 3
>4pCi/L
> 2.5 ppm eU
positive
high
mostly basement
*GEOLOGIC FIELD EVIDENCE (GFE) POINTS: GFE points are assigned in addition to points
for the "Geology" factor for specific, relevant geologic field studies. See text for details.
Geologic evidence supporting: HIGH radon +2 points
MODERATE +1 point
LOW -2 points
No relevant geologic field studies 0 points
SCORING:
Radon potential category
Pointrange
Probable average screening
indoor radon for area
LOW
MODERATE/VARIABLE
HIGH
3-8 points
9-11 points
12-17 points
<2pCi/L
2 - 4 pCi/L
>4pCi/L,
POSSIBLE RANGE OF POINTS = 3 to 17
TABLE 2.
CONFIDENCE INDEX MATRIX
INCREASING CONFIDENCE
FACTOR
INDOOR RADON DATA
AERIAL RADIOACTIVITY
GEOLOGIC DATA
SOIL PERMEABILITY
POINT VALUE
1
sparse/no data
questionable/no data
questionable
questionable/no data
2
fair coverage/quality
glacial cover
variable
variable
3
good coverage/quality
no glacial cover
proven geol. model
reliable, abundant
SCORING:
LOW CONFIDENCE
MODERATE CONFIDENCE
HIGH CONFIDENCE
4-6 points
7-9 points
10 -12 points
POSSIBLE RANGE OF POINTS = 4 to 12
11-12. Reprinted from USGS Open-File Report 93-292
-------
included as supplementary information and are discussed in the individual State chapters. If
the average screening indoor radon level for an area was less than 2 pCi/L, the indoor radon
factor was assigned 1 point, if it was,between 2 and 4 pCi/L, it was scored 2 points, arid if ,
the average screening indoor radon level for an area was greater than 4 pCi/L, the indoor
radon factor was assigned 3 RI points. , >
Aerial radioactivity data used in this report are from the equivalent uranium map of the
conterminous United States compiled from NURE aerial gamma-ray surveys (Duval and
others, 1989). These, data indicate the gamma radioactivity from approximately the upper 30
cm of rock and soil, expressed in units of ppm equivalent uranium. An approximate average
value of
-------
been leached from the upper soil layers but are present and possibly even concentrated in
deeper soil horizons, generating significant soil-gas radon. This positive supporting field
evidence adds two GFE points to the score, which helps to counteract the invalid conclusion
suggested by the radiometric data. No GFE points are awarded if there are no documented
field studies for the area.
"Soil permeability" refers to several soil characteristics that influence radon concentration
and mobility, including soil type, grain size, structure, soil moisture, drainage, slope, and
permeability. In the matrix, "low" refers to permeabilities less than about 0.6 in/hr; "high"
corresponds to greater than about 6.0 in/hr, in U.S. Soil Conservation Service (SCS) standard
soil percolation tests. The SCS data are for water permeability, which generally correlates
well with the gas permeability of the soil except when the .soil moisture content is very high.
Areas with consistently high water tables were thus considered to have low gas permeability.
"Low, "moderate", and "high" permeability were assigned 1, 2, and 3 points, respectively.
Architecture type refers to whether homes in the area have mostly basements (3 points),
mostly slab-on-grade construction (1 point), or a mixture of the'two. Split-level and crawl
space homes fall into the "mixed" category (2 points). Architecture information is necessary
to properly interpret the indoor radon data and produce geologic radon potential categories
that are consistent with screening indoor radon data.
The overall RI for an area is calculated by adding the individual RI scores for the 5
factors, plus* or minus GFE points, if any. The total RI for an area falls in one of three
categories—low, moderate or variable, or high. The point ranges for the three categories were
determined by examining the possible combinations of points for the 5 factors and setting
rules such that a majority (3 of 5 factors) would determine the final score for the low and
high categories, with allowances for possible deviation "from an ideal score by the other two
factors. The moderate/variable category lies between these two ranges. A total deviation of 3
points from the "ideal" score was considered reasonable to allow for natural variability of
factors—if two of the five factors are allowed to vary from the "ideal" for a category, they
can differ by a minimum of 2 (1 point different each) and a maximum of 4 points (2 points.
different each). With "ideal" scores of 5, 10, and 15 points describing low, moderate, and
high geologic radon potential, respectively, an ideal low score of 5 points plus 3 points for
possible variability allows a maximum of 8 points in the low category. Similarly, an ideal
high score of 15 points minus 3 points gives a minimum of 12 points for the high category.
Note, however, that if both other factors differ by two points from the "ideal", indicating
considerable variability in the system, the total point score would lie in the adjacent (i.e.,
moderate/variable) category.
Confidence Index. Except for architecture type, the same factors were used to establish a
Confidence Index (CI) for the radon potential prediction for each area (Table 2). Architecture
type was not included in the confidence index because house construction data are readily and
reliably available through surveys taken by agencies and industry groups including the
National Association of Home Builders, U.S. Department of Housing and Urban '
Development, and the Federal Housing Administration; thus it was not considered necessary
II-14 Reprinted from USGS Open-File Report 93-292
-------
to question the quality or validity of these data. The other factors were scored on the basis of
the quality and quantity of the data used to complete the RI matrix. '
Indoor radon data were evaluated based on the distribution arid number of data points and
on whether the data were collected by random sampling (State/EPA Residential Radon Survey ,
or other state survey data) or volunteered vendor data (likely to be nohfandom-and biased
toward population centers and/or high indoor radon levels). The categories Ijsted in the CI
matrix for indoor radon data ("sparse or no data", "fair coverage or quality", and "good
coverage/quality") indicate the sampling density and statistical robustness of an indoor radon
data set. .Data from the State/EPA-Residential Radon Survey and statistically valid state
surveys .were typically assigned 3 Confidence Index points unless the data were poorly
distributed or absent in the area evaluated.
Aerial radioactivity data, are available for all but a few areas of the continental United
' States and for part of Alaska. .An evaluation of the quality of the radioactivity data was based
on whether there appeared to be a good correlation between the radioactivity and the actual
amount of uranium or.radium available to generate mobile radon in the rocks and soils of the
area evaluated. In general,. the;greatest problems with .correlations among eU, geology, and
•soil-gas or indoor radon levels were associated with glacial deposits (see the discussion in a
previous section) and typically were assigned a 2-p'oint Confidence Index score: Correlations
among eU, geology, and radon'were generally sound in unglaciated areas and were usually
assigned 3 CI points. Again, however, radioactivity data in some unglaciated areas may have
been assigned fewer than 3 points, and in glaciated areas may be. assigned'only one point,-if .
the data were considered1 questionable or if coverage was poor.
To assign. Confidence index scores for the geologic data factor, rock types and geologic '
settings for which a physical-chemical, process-based understanding of radon generation and
mobility exists were regarded as having "proven geologic models" (3 points); a high
confidence could be held for predictions in such areas. Rocks for which the processes are
less well known or for which data are contradictory were regarded as "variable" (2 points),
and those about which little i-s known or for .which no apparent correlations,have been found
were deemed "questionable" (1 point).
The soil permeability factor was also scpred based on quality and amount of data. The
three'categories for soil permeability in the Confidence Index are similar in concept, and
scored similarly, to those for the geologic data factor. ' Soil permeability can be roughly
estimated from grain size and drainage class if data from standard, accepted soil percolation-
tests are unavailable;'however, the reliability of the data would be lower than if percolation
test figures or other measured permeability data are available, because an estimate of this type
does not encompass all the factors that affect soil permeability and thus may be inaccurate in
some instances. Most published soil permeability data are for water; although this is
generally closely related to the air permeability of the soil, there are some instances when it
may provide an1 incorrect estimate. Examples of areas in which water permeability data may
not accurately reflect air permeability include areas with consistently high levels of soil
moisture, or clay-rich, soils; which would have a low water permeability but may have a
11-15, Reprinted frpmUSGS Open-File Report 93-292
-------
significantly higher air permeability when dry due to shrinkage cracks in the soil. These
additional factors were applied to the soil permeability factor when assigning the RI score, but
may have less certainty in some cases and thus would be assigned a lower CI score.
The Radon Index and Confidence Index give a general indication of the relative
contributions of the interrelated geologic factors influencing radon generation and transport in
rocks and soils, and thus, of the potential for elevated indoor radon levels to occur in a
particular area. However, because these reports are somewhat generalized to cover relatively
large areas of States, it is highly recommended that more detailed studies be performed in
local areas of interest, using the methods and general information in these booklets as a guide.
11-16 Reprinted from USGS Open-File Report 93-292
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REFERENCES CITED
Akerblom, G;, Anderson, P., and Clavensjo, B., 1984, Soil gas radon-A source for indoor radon
daughters: Radiation Protection Dosimetry, v. 7, p. 49-54.
Deffeyes, K.S., and MacGregor, I.D., 1980, World uranium resources: Scientific American,
v. 242, p. 66-7.6.
Durrance, E.M., 1986, Radioactivity in geology: Principles and applications: New York, N.Y.,
Wiley and Sons, 441 p.
Duval, J.S., 1989, Radioactivity and some of its applications in geology: Proceedings of the
symposiumon the application of geophysics to engineering and environmental problems
(S AGEEP), Golden, Colorado, March 13-16,1989: Society of Engineering and Mineral
Exploration Geophysicists, p. 1-61.
Duval, J.S., Cook, E.G., and Adams, J.A.S., 1971, Circle of investigation of an airborne
gamma-ray spectrometer: Journal of Geophysical Research, v. 76, p. 8466-8470.
Duval, T.S., Jones, W.J., Riggle, F.R., and Pitkin, J.A., 1989, Equivalent uranium map of
conterminous United States: U.S. Geological Survey Open-File Report 89-478,10 p.
Duval, J.S., Reimer, G.M., Schumann, R.R., Owen, D.E., and Otton, J.K., 1990, Soil-gas
radon compared to aerial and ground gamma-ray measurements at study sites near Greeley
and Fort Collins, Colorado: U.S. Geological Survey Open-File Report 90-648,42 p.
Dziuban, J.A., Clifford, M.A., White, S.B., Bergstein, J.W., and Alexander, B.V., 1990,
Residential radon survey of twenty-three States, in Proceedings of the 1990 International
Symposium on Radon and Radon Reduction Technology, Vol. UJ: Preprints: U.S.
Environmental Protection Agency report EPA/600/9-90/005c, Paper IV-2,17 p. v
Gammage, R.B., Wilson, D.L., Saultz, R.J., and Bauer, B.C., 1993, Subtereanean transport of
radon and elevated indoor radon in hilly karst terranes: Atmospheric Environment
(in press).
Gundersen, L.C.S., Reimer, G.M., and Agard, S.S., 1988a, Correlation between geology, radon
in soil gas, .and indoor radon in the Reading Prong, in Marikos, M.A., and Hansman,
R.H., eds., Geologic causes of natural radionuclide anomalies: Missouri Department of
Natural Resources Special Publication 4, p. 91-102. .
Gundersen, L.C.S, Reimer, G.M., Wiggs, C.R., and Rice, C.A., 1988b, Map showing radon
; potential of rocks and soils in Montgomery County, Maryland: U.S. Geological Survey
Miscellaneous Field Studies Map MF-2043, scale 1:62,500. ,
Gundersen, Linda C.S., 1991, Radon in sheared metaniorphic and igneous rocks, in Gundersen,
Linda C.S., and Richard B. Wanty, eds., Field studies of radon in rocks, soils, and water:
. U.S. Geol. Survey Bulletin no. 1971, p. 39-50.
TI-17 " Reprinted fomUSGS Open-File Report 93-292
-------
Henry, Mitchell E., Kaeding, Margret E., and Monteverde, Donald, 1991, Radon in soil gas and
gamma-ray activity of rocks and soils at the Mulligan Quarry, Clinton, New Jersey, in
Gundersen, Linda C.S., and Richard B. Wanty, eds., Field studies of radon in rocks,
soils, and water: U.S. Geol. Survey Bulletin no. 1971, p. 65-75.
Klusman, R. W., and Jaacks, J. A., 1987, Environmental influences upon mercury, radon, and
helium concentrations in soil gases at a site near Denver, Colorado: Journal of
Geochemical Exploration, v. 27, p. 259-280.
Kovach, E.M., 1945, Meteorological influences upon the radon content of soil gas: Transactions,
American Geophysical Union, v. 26, p. 241-248..
Kunz, C., Laymon, C.A., and Parker, C., 1989, Gravelly soils and indoor radon, in Osborne,
M.C., and Harrison, J., eds., Proceedings of the 1988 EPA Symposium on Radon and
Radon Reduction Technology, Volume 1: U.S. Environmental Protection Agency Report
EPA/600/9-89/006A, p. 5-75-5-86.
Muessig, K., and Bell, C., 1988, Use of airborne radiometric data to direct testing for elevated
indoor radon: Northeastern Environmental Science, v. 7, no. 1, p. 45-51.
Ronca-Battista, M., Moon, M., Bergsten, J., White, S.B., Holt, N., and Alexander, B., 1988,
Radon-222 concentrations in the United States—Results of sample surveys in five states:
Radiation Protection Dosimetry, v. 24, p. 307-312.
Rose, A.W., Washington, J.W., and Greeman, D.J., 1988, Variability of radon with depth and
season in a central Pennsylvania soil developed on limestone: Northeastern Environmental
Science, v. 7, p. 35-39.
Schery, S.D., Gaeddert, D.H., and Wilkening, M.H., 1984, Factors affecting exhalation of radon
from a gravelly sandy loam: Journal of Geophysical Research, v. 89, p. 7299-7309.
Schumann, R.R., and Owen, D.E., 1988, Relationships between geology, equivalent uranium
concentration, and radon in soil gas, Fairfax County, Virginia: U.S. Geological Survey
Open-File Report 88-18,28 p.
Schumann, R.R., and Gundersen, L.C.S., 1991, Regional differences in radon emanation
coefficients in soils: Geological Society of America Abstracts With Programs, v. 23,
no. 1, p. 125.
Schumann, R.R., Peake, R.T., Schmidt, K.M., and Owen, D.E., 1991, Correlations of soil-gas
and indoor radon with geology in glacially derived soils of the northern Great Plains, in
Proceedings of the 1990 International Symposium on Radon and Radon Reduction
Technology, Volume 2, Symposium Oral Papers: U.S. Environmental Protection Agency
report EPA/600/9-9 l/026b, p. 6-23-6-36.
JJ-18 Reprinted from USGS Open-File Report 93-292
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Schumann, R.R., Owen, D.E., and Asher-Bolinder, S., 1992, Effects of weather and soil
characteristics on temporal variations in soil-gas radon concentrations, in Gates, A.E., and
Gundersen, L.C.S., eds., Geologic controls on radon: Geological Society of America
Special Paper 271, p. 65-72. ,
Sextro, R.G., Moed, B.A., Nazaroff, W.W., Revzan, K.L., and Nero, A.V., 1987, ;
Investigations of soil as a source of indoor radon, in Hopke, P.K., ed;, Radon and its
decay products: American Chemical Society Symposium Series 331, p. 10-29.
Sterling, R., Meixel, G., Shen, L., Labs, K., and Bligh, T., 1985, Assessment of the energy
savings potential of building foundations research: Oak Ridge, Tenn., U.S. Department of
Energy Report ORNL/SUB/84-0024/1. ..-'•' ., " ,
Smith, R.C., H, Reilly, M.A., Rose, A.W., Barnes, J.H., and Berkheiser, S.W., Jr., 1987,
Radon: a profound case: Pennsylvania Geology, v. 18, p. 1-7. ;
Tanner, A.B., 1964, Radon migration in the ground: a review, in Adams, J.A.S., and Lowder,
W.M., eds., The natural radiation environment: Chicago, EL, University of Chicago
Press, p. 161-190.
Tanner, A.B., 1980, Radon migration in the ground: a supplementary review, in Gesell, T.F.,
and Lowder, W.M. (eds), Natural radiation environment HI, Symposium proceedings,
Houston, Texas, v. 1, p. 5-56.
U.S. Department of Agriculture, 1987, Principal kinds of soils: Orders, suborders, and great
groups: U.S. Geological Survey, National Atlas of the United States of America, sheet
38077-BE-NA-07M-00, scale 1:7,500,000.
U.S. Department of Energy, 1976, National Uranium Resource Evaluation prelimuiary report,
prepared by the U.S. Energy Research and Development Administration, Grand Junction,
Colo.: GJO-11(76).
Wanty, Richard B., and Schoen, Robert, 1991, A review of the chemical processes affecting the -
mobility of .radionuclides in natural waters, with applications, in Gundersen, Linda C.S.,
' and Richard B. Wanty, eds., Field studies of radon in rocks, soils, and water: U.S.
• Geological Survey Bulletin no. 1971, p.-183-194.. •
Washington, J.W., and Rose, A.W., 1990, Regional and temporal relations of radon in soil gas to
soil temperature and moisture: Geophysical Research Letters, v. 17, p. 829-832.
White, S.B., Bergsten, J.W., Alexander, B.V., and Ronca-Battista, M., 1989, Multi-State
surveys of indoor 222Rh: Health Physics, v. 57, p. 891-896.
n-19 Reprinted from USGSOpen-FUe Report 93-292
-------
-------
APPENDIX A
GEOLOGIC TIME SCALE
- • Subdivisions (end their s-, nbols)
Eon or
Eonothem
Pnanerozoic
Proterozoic
(B)
Archean
(A)
Era or
Erathem
Cenozoic2
Permian,
(P)
Pennsylvanian
Carboniferous 'P'
(C) Mississippian
(M)
Devonian
-------
-------
APPENDIX B
GLOSSARY OF TERMS
Units of measure
pCi/L (picocuries per liter)- a unit of measure of radioactivity used to describe radon
concentrations in a volume of air. One picocurie (10'12 curies) is equal to about 2.2 disintegrations
of radon atoms per minute. A liter is about 1.06 quarts. The average concentration of radon in
U.S. homes measured to date is between 1 and 2 pCi/L.
Bq/m3 (Becquerels per cubic meter)- a metric unit of radioactivity used to describe radon
concentrations in a volume of air. One becquerel is equal to one radioactive disintegration per
second. One pCi/L is equal to 37 Bq/m3. ,
ppm (parts per million)- a unit of measure of concentration by weight of an element in a
substance, in this case, soil or rock. One ppnxof uranium contained in a ton of rock corresponds
to about 0.03 ounces of uranium.. The average concentration of uranium in soils in the United
States is between 1 and 2 ppm.
in/hr (inches per hour)- a unit of measure used by soil scientists and engineers to describe the
permeability of a soil to water flowing through it It is measured by digging a hole 1 foot (12
inches) square and one foot deep, filling it with water, and measuring the time it takes for the water
to drain from the hole. The drop in height of the water level in the hole, measured in inches, is
then divided by the time (in hours) to determine the permeability. Soils range in permeability from
less than 0.06 in/hr to greater than 20 in/hr, but most soils in the United States have permeabilities
between these two extremes.
Geologic terms and terms related to the study of radon
aerial radiometric, aeroradiometric survey A survey of radioactivity, usually gamma rays,
taken by an aircraft carrying a gamma-ray spectrometer pointed at the ground surface;
alluvial fan A low, widespread mass of loose rock and soil material, shaped like an open fan
and deposited by a stream at the point where it flows from a narrow mountain valley out onto a
plain or broader, valley. May also form at the junction with larger streams or when the gradient of
the stream abruptly decreases.
alluvium, alluvial General terms referring to unconsolidated detrital material deposited by a
stream or other body of running water.
alpha-track detector A passive radon measurement device consisting of a plastic film that is
sensitive to alpha particles. The film is etched with acid in a laboratory after it is exposed. The
etching reveals scratches, or "tracks", left by the alpha particles resulting from radon decay, which
can then be counted to calculate the radon concentration. Useful for long-term (1-12 months)
radon tests. - ,
amphibolite A mafic metamorphic rock consisting mainly of pyroxenes and(or) amphibole and
plagioclase. ., ;
n-21 Reprinted from USGS Open-File Report 93-292
-------
argillite, argillaceous Terms referring to a rock derived from clay or shale, or any sedimentary
rock containing an appreciable amount of clay-size material, i.e., argillaceous .sandstone.
arid Term describing a climate characterized by dryness, or an evaporation rate that exceeds the
amount of precipitation.
basalt A general term for a dark-colored mafic igneous rocks that may be of extrusive origin,
such as volcanic basalt flows, or intrusive origin, such as basalt dikes.
batholith A mass of plutonic igneous rock that has more than 40 square miles of surface
exposure and no known bottom.
carbonate A sedimentary rock consisting of the carbonate (COs) compounds of calcium,
magnesium, or iron, e.g. limestone and dolomite.
carbonaceous Said of a rock or sediment that is rich in carbon, is coaly, or contains organic
matter.
charcoal canister A passive radon measurement device consisting of a small container of
granulated activated charcoal that is designed to adsorb radon. Useful for short duration (2-7 days)
measurements only. May be referred to as a "screening" test
chert A hard, extremely dense sedimentary rock consisting dominantly of interlocking crystals of
quartz. Crystals are not visible to the naked eye, giving the rock a milky, dull luster. It may be
white or gray but is commonly colored red, black, yellow, blue, pink, brown, or green.
clastic pertaining to a rock or sediment composed of fragments that are derived from preexisting
rocks or minerals. The most common clastic sedimentary rocks are sandstone and shale.
clay A rock containing clay mineral fragments or material of any composition having a diameter
less than 1/256 mm.
clay mineral One of a complex and loosely defined group of finely crystalline minerals made up
of water, silicate and aluminum (and a wide variety of other elements). They are formed chiefly by
alteration or weathering of primary silicate minerals. Certain clay minerals are noted for their small
size and ability to absorb substantial amounts of water, causing them to swell. The change in size
that occurs as these clays change between dry and wet is referred to as their "shrink-swell"
potential. •
concretion A hard, compact mass of mineral matter, normally subspherical but commonly
irregular in shape; formed by precipitation from a water solution about a nucleus or center, such as
a leaf, shell, bone, or fossil, within a sedimentary or fractured rock.
conglomerate A coarse-grained, clastic sedimentary rock composed of rock and mineral
fragments larger than 2 mm, set in a finer-grained matrix of clastic material.
cuesta A hill or ridge with a gentle slope on one side and a steep slope on the other. The
formation of a cuesta is controlled by the different weathering properties and the structural dip of
the rocks forming the hill or ridge.
daughter product A nuclide formed by the disintegration of. a radioactive precursor or "parent"
atom.
H-22 Reprinted from USGS Open-File Report 93-292
-------
delta, deltaic Referring to a low, flat, alluvial tract of land having a triangular or fan shape,
located at or .near the mouth of a river. It results from the accumulation of sediment deposited by a
river at the point at which the river Ipses its ability to transport the sediment, commonly where a
river meets a larger body of water such as a lake or ocean.
dike A tabular igneous intrusion of rock, younger than the surrounding rock, that commonly cuts
, across the bedding or foliation of the rock it intrudes. ' , ,
diorite A plutonic igneous rock that is medium in color and contains visible dark minerals that
make up less than 50% of the rock. It also contains abundant sodium plagioclase and minor
quartz. .
i , - • '.'•',•
dolomite A carbonate sedimentary rock of which more than 50% consists of the mineral dolomite
(CaMg(CO3)2), and is commonly white, gray, brown, yellow, or pinkish in color. .
drainage The manner in which the waters of an area pass, flow off of, or flow into the soil.
Also refers to the water features of an area, such as lakes and rivers, that drain it
i~ . / ..'•''• ' ' ' ' . • - - •''~ . '
eolian Pertaining to sediments deposited by the wind. •
esker A long, narrow, steep-sided ridge composed of irregular beds of sand and gravel deposited
by streams beneath a glacier and left behind when the ice melted.
— " ' - • h
evapotranspiration Loss of water from a land area by evaporation from the soil and
transpiration from plants.
extrusive Said of igneous rocks that have been erupted onto the surface of the Earth.
fault A fracture or zone of fractures in rock or sediment along which there has been movement.
fluvial, fluvial deposit Pertaining to sediment that has been deposited by a river or stream.
foliation A linear feature in a rock defined by both mineralogic and structural characteristics. It
may be formed during deformation or metamorphism.
formation A mappable body of rock having similar characteristics.
glacial depjosit Any sediment transported and deposited by a glacier or processes associated
with glaciers, such as glaciofiuyial sediments deposited by streams flowing from melting glaciers.
i , •
gneiss A rock formed by metamorphism in which bands and lenses of minerals of similar
composition alternate with bands and lenses of different composition, giving the rock a striped or
"foliated" appearance.
granite Broadly applied, any coarsely crystalline, quartz- and feldspar-bearing igneous plutonic
rock. Technically, granites have between 10 and 50% quartz, and alkali feldspar comprises at least
65% of the total feldspar. .
gravel An unconsolidated, natural accumulation of rock fragments consisting predominantly of
particles greater than 2 mm in size.
f -.'',• " .'. • '''<'•'
heavy minerals Mineral grains in sediment or sedimentary rock having higher than average
specific gravity. May form layers and lenses because of wind or water sorting by weight and size
II-23 .Reprinted from USGS Open-File Report 93-292
-------
and may be referred to as a "placer deposit." Some heavy minerals are magnetite, garnet, zircon,
monazite, and xenotime.
igneous Said of a rock or mineral that solidified from molten or partly molten rock material. It is
one of the three main classes into which rocks are divided, the others being sedimentary and
metamorphic. ,
intermontane A term that refers to an area between two mountains or mountain ranges.
intrusion, intrusive The processes of emplacement or injection of molten rock into pre-existing
rock. Also refers to the rock formed by intrusive processes, such as an "intrusive igneous rock".
! •.','.
kame A low mound, knob, hummock, or short irregular ridge formed by a glacial stream at the
margin of a melting glacier; composed of bedded sand and gravel.
karst terrain A type of topography that is formed on limestone, gypsum and other rocks by
dissolution of the rock by water, forming sinkholes and caves.
lignite A brownish-black coal that is intermediate in coalification between peat and
subbituminous coal.
limestone A carbonate sedimentary rock consisting of more than 50% calcium carbonate,
primarily in the form of the mineral calcite (CaCOs).
lithology The description of rocks in hand specimen and in outcrop on the basis of color,
composition, and grain size.
loam A permeable soil composed of a mixture of relatively equal parts clay, silt, and sand, and
usually containing some organic matter.
loess A fine-grained eolian deposit composed of silt-sized particles generally thought to have
been deposited from windblown dust of Pleistocene age.
mafic Term describing an igneous rock containing more than 50% dark-colored minerals.
marine Term describing sediments deposited in the ocean, or precipitated from ocean waters.
metamorphic Any rock derived from pre-existing rocks by mineralogical, chemical, or structural
changes in response to changes in temperature, pressure, stress, and the chemical environment.
Phyllite, schist, amphibolite, and gneiss are metamorphic rocks.
moraine A mound, ridge, or other distinct accumulation of unsorted, unbedded glacial material,
predominantly till, deposited by the action of glacial ice.
outcrop That part of a geologic formation or structure that appears at the surface of the Earth, as
in "rock outcrop". .
percolation test A term used in engineering for a test to determine the water permeability of a
soil. A hole is dug and filled with water and the rate of water level decline is measured.
permeability The capacity of a rock, sediment, or soil to transmit liquid or gas.
phosphate, phosphatic, phosphorite Any rock or sediment containing a significant amount
of phosphate minerals, i.e., minerals containing PO4.
11-24 Reprinted from USGS Open-File Report 93-292
-------
physiographic province A region in which all parts are similar in geologic structure and
climate, which has had a uniform geomorphic history, and whose topography or landforms differ
significantly from adjacent regions.
nlacer deposit See heavy minerals
residual Formed by weathering of a material in place. " •
residuum Deposit of residual material.
rhyolite An extrusive igneous rock of volcanic origin, compositionally equivalent to granite. ,
sandstone A clastic sedimentary rock composed of sand-sized rock and mineral material that is
more or less firmly cemented. Sand particles range from 1/16 to 2 mm in size.
. schist A strongly foliated crystalline rock, formed by metamorphism, that can be readily split into
thin flakes or slabs. Contains mica; minerals are typically aligned.
screening level Result of an indoor radon test taken with a charcoal canister or similar device,
far A short period of time, usually less than seven days; May indicate the potential for an indoor
radon problem but does not indicate annual exposure to radon.
sediment Deposits of rock and mineral particles x>r fragments originating from material that is
transported by air, water or ice, or that accumulate by natural chemical precipitation or secretion of
organisms. . ...
semiarid Refers to a climate that has slightly more precipitation thari an arid climate.
shale A fine-grained sedimentary rock formed from solidification (Hthification) of clay or mud.
shear zone Refers to. a roughly linear zone of rock that has been faulted by ductile or non-ductile
processes in which the rock is sheared and both sides are displaced relative to one another.
shrink-swell clay See clay mineral.
siltstone A fine-grained clastic sedimentary rock composed of silt-sized rock and mineral
material and more or less firmly cemented. Silt particles range from 1/16 to 1/256 mm in size.
sinkhole A roughly circular depression in a karst area measuring meters to tens of meters in
diameter. It is funnel shaped and is formed by collapse of the surface material into an underlying
void created by trie dissolution of carbonate rock. ; .
slope An inclined part of the earth's surface.
solution cavity A hole, channel or cave-like cavity formed by dissolution of rock.
, stratigraphy The study of rock strata; also refers to the succession of rocks of a particular area.
surficial materials Unconsolidated glacial,'wind-, or waterborne deposits occurring on the
earth's surface.
tablelands General term for a broad, elevated region with a nearly level surface of considerable
extent -
11-25 Reprinted from USGS Open-File Report 93-292
-------
terrace gravel Gravel-sized material that caps ridges and terraces, left behind by a stream as it
cuts down to a lower level.
terrain A tract or region of the Earth's surface considered as a physical feature or an ecological
environment
till Unsorted, generally unconsolidated and unbedded rock and mineral material deposited directly
adjacent to and underneath a glacier, without reworking by meltwater. Size of grains varies greatly
from clay to boulders.
uraniferous Containing uranium, usually more than 2 ppm.
vendor data Used in this report to refer to indoor radon data collected and measured by
commercial vendors of radon measurement devices and/or services.
volcanic Pertaining to the activities, structures, and extrusive rock types of a volcano.
water table The surface forming the boundary between the zone of saturation and the zone of
aeration; the top surface of a body of unconfined groundwater in rock or soil.
weathering The destructive process by which earth and rock materials, on exposure to
atmospheric elements, are changed in color, texture, composition, firmness, or form with little or
no transport of the material.
11-26 Reprinted from USGS Open-File Report 93-292
-------
APPENDIX G
EPA REGIONAL OFFICES
EPA Regional Offices
State
EPA Region
EPA Region 1
JFK Federal Building ;
Boston, MA 02203
(617) 565-4502
EPA Region 2
(2AIR:RAD)
26 Federal Plaza
New York, NY 10278
(212) 264-4110
Region 3 (3AH14)
841 Chestnut Street .- ..
Philadelphia, PA 19107
(215) 597-8326
EPA Region 4
345 Courtland Street, N.E.
Atlanta, GA 30365'
(404)347-3907
EPA Region 5 (5AR26)
77 West Jackson Blvd.
Chicago, IL 60604-3507
(312) 886-6175
'EPA Region 6 (6T-AS)
1445 Ross Avenue
Dallas, TX 75202-2733
(214) 655-7224
EPA Region 7
726 Minnesota Avenue
Kansas City, KS 66101
(913). 551-7604
EPA Region 8
(8HWM-RP)
999 18th Street
One Denver Place, Suite 1300
Denver, CO 80202-2413 ,
(303) 293-1713
EPA Region 9 (A-3)
75 Hawthorne Street
San Francisco, CA 94105 .,
(415) 744-1048
EPA Regipn 10
1200 Sixth Avenue
Seattle, WA 98101
(202) 442-7660
Alabama... —..4
Alaska..., . 10
Arizona.. .. .' 9
Arkansas... 6
California.. '.....9-
Colorado... 8
Connecticut..., ...1
Delaware.. , 3
District of Columbia 3
Florida.... ...:.... .......4
Georgia.. ,. .....4
Hawaii 9
Idaho ....... ...-10"
Illinois...—; '........'.... 5
Indiana, ; 5
Iowa..; 7.
Kansas .....: 7
Kentucky.. , ...4 •
Louisiana 6
Maine... '.i ....1
' Maryland ......3
Massachusetts......... , ......1
Michigan ..5
.Minnesota -.... 5
Mississippi , 4
Missouri 7 •
Montana..... 8
Nebraska............ 7
Nevada .9
New Hampshire.....; ..1
.New Jersey 2
New Mexico 6
New York... ..i ...:...2
North Carolina ;.....4
North Dakota 8
Ohio '. , 5
Oklahoma........ 6
Oregon ,. 101
Pennsylvania '. ••••3
Rhode Island,... 1
South Carolina ;....'...4
South Dakota ..8
Tennessee .....* 4
Texas 6
Utah......... . 8
Vermont.. ; 1
Virginia i '....3
Washington 10
West Virginia .....3
Wisconsin 5
Wyoming......... 8
H-27 Reprinted from USGS Open-File Report 93-292
-------
STATE RADON CONTACTS
May, 1993
Alabama James McNees
Division of Radiation Control
Alabama Department of Public Health
State Office Building
Montgomery, AL 36130
(205)242-5315
1-800-582-1866 in state
Alaska Charles Tedford
Department of Health and Social
Services
P.O. Box 110613
Juneau,AK 99811-0613
(907)465-3019
1-800-478-4845 in state
Arizona . John Stewart
Arizona Radiation Regulatory Agency
4814 South 40th St.
Phoenix, AZ 85040
(602) 255-4845
Arkansas Lee Gershner
Division of Radiation Control
Department of Health
4815 Markham Street, Slot 30
Little Rock, AR 72205-3867
(501) 661-2301
California J. David Quinton
Department of Health Services
714 P Street, Room 600
Sacramento, CA 94234-7320
(916) 324-2208
1-800-745-7236 in state
Colorado Linda Martin
Department of Health
4210 East llth Avenue
Denver, CO 80220
(303) 692-3057
1-800-846-3986 in state
Connecticut Alan J. Siniscalchi
Radon Program
Connecticut Department of Health
Services
150 Washington Street
Hartford, CT 061064474
(203)566-3122
Delaware MaraiG.Rejai
Office of Radiation Control
; ' Division of Public Health
P.O. Box 637
Dover, DE 19903
(302)736-3028
, 1-800-554-4636 In State
District Robert Davis
of Columbia DC Department of Consumer and
Regulatory Affairs
614 H Street NW
Room 1014
Washington, DC 20001
(202)727-71068
Florida N. Michael Gilley
Office of Radiation Control
Department of Health and
Rehabilitative Services
1317 Winewood Boulevard
Tallahassee, EL 32399-0700
(904)488-1525
1-800-543-8279 in state
Richard Schreiber
Georgia Department of Human
Resources
878 Peachtree St., Room 100
Atlanta, GA 30309
(404) 894-6644
1-800-745-0037 in state
Hawaii Russell Takata . *
Environmental Health Services
Division
591 Ala Moana Boulevard
Honolulu, ffl 96813-2498
(808)5864700
H-28
Reprinted from USGS Open-File Report 93-292
-------
Idaho
Indiana
Iowa
Kansas
Kentucky
PatMcGavarn
Office of Environmental Health
450 West State Street
Boise, ID 83720
(208) 334-6584
1-800-445-8647 in state
Richard Allen
Illinois Department of Nuclear Safety
1301 Outer Park Drive
Springfield, IL 62704
(217)524-5614
1-800-325-1245 in state
Lorand Magyar
Radiological Health Section-
Indiana State Department of Health
1330 West Michigan Street
P.O. Box 1964
Indianapolis, IN 46206
(317) 633-8563 .
1-800-272-9723 In State
Donald A. Plater
Bureau of Radiological Health
Iowa Department of Public Health
Lucas State Office Building
Des Moines, IA 50319-0075 .
(515)281-3478
1-800^383-5992 In State
Harold Spiker
Radiation Control Program
Kansas Department of Health and
Environment
109 SW 9th Street
6th Floor Mills Building
Topeka, KS 66612
(913) 296-1561
JeanaPhelps
Radiation Control Branch
Department of Health Services
Cabinet for Human Resources
275 East Main Street
Frankfort, KY 40601
(502) 564-3700
,,. Louisiana Matt Schlenker
Louisiana Department of
Environmental Quality
P.O. Box 82135
Baton Rouge, LA 70884-2135
(504)925-7042 ,
., 1-800-256-2494 in state
Maine BobStilwell
Division of Health Engineering
Department of Human Services
State House, Station. 10
Augusta, ME 04333 -.
(207)289-5676
1-800-232-0842 in state
Maryland Leon J. Raehuba
Radiological Health Program
Maryland Department of the >
'••'-.' Environment
2500 Broening Highway
Baltimore, MD 21224
(410)631-3301
1-800-872-3666 In State
Massachusetts William J. Bell
Radiation Control Program
Department of Public Health
23 Service Center
Northampton, MA 01060
.. , (413)586-7525
1-800-445-1255 in state
Michigan SueHendershott
Division of Radiological Health
. Bureau of Environmental and
Occupational Health
3423 North Logan Street
P.O. Box 30195
Lansing, MI 48909
(517) 335-8194
Mihnesdta Laura Oatmann
Indoor Air Quality Unit .
v 925 Delaware Street, SE
P.O. Box 59040
Minneapolis, MN 55459-0040
(612)627-5480
1-800-798-9050 in state
n-29 . Reprinted from USGS Open-File Report 93-292
-------
Mississippi Silas Anderson
Division of Radiological Health
Department of Health
3150 Lawson Street
P.O. Box 1700
Jackson, MS 39215-1700
(601) 354-6657
1-800-626-7739 in state
Missouri Kenneth V. Miller
Bureau of Radiological Health
Missouri Department of Health
1730 East Elm
P.O. Box 570
Jefferson City, MO 65102
(314) 751-6083
1-800-669-7236 In State
Montana Adrian C. Howe
Occupational Health Bureau
Montana Department of Health and
Environmental Sciences
Cogswell Building A113
Helena, MT 59620
(406)444-3671
Nebraska Joseph Milone
Division of Radiological Health
Nebraska Department of Health
301 Centennial Mall, South
P.O. Box 95007
Lincoln, NE 68509
(402)471-2168
1-800-334-9491 In State
Nevada Stan Marshall
Department of Human Resources
505 East King Street
Room 203
Carson City, NV 89710
(702) 687-5394
Mca Hampshire David Chase
Bureau of Radiological Health
Division of Public Health Services
Health and Welfare Building
Six Hazen Drive
Concord, NH 03301
(603)271-4674
1-800-852-3345 x4674
New Jersey Tonalee Carlson Key
Division of Environmental Quality
Department of Environmental
Protection
CN415
Trenton, NJ 08625-0145
(609) 987-6369
1-800-648-0394 in state
New Mexico William M. Floyd
Radiation Licensing and Registration
Section
New Mexico Environmental
Improvement Division
1190 St. Francis Drive
Santa Fe,NM 87503
(505)827-4300
New York William J. Condon
Bureau of Environmental Radiation
Protection
New York State Health Department
Two University Place
Albany, NY 12202
(518)458-6495
1-800-458-1158 in state
North Carolina Dr. Felix Fong
Radiation Protection Division'
Department of Environmental Health
and Natural Resources
701 Barbour Drive
Raleigh, NC 27603-2008 -
(919) 571-4141
1-800-662-7301 (recorded info x4196)
North Dakota Arlen Jacobson
North Dakota Department of Health
1200 Missouri Avenue, Room 304
P.O. Box 5520
Bismarck, ND 58502-5520
(701)221-5188
Ohio Marcie Matthews
Radiological Health Program
Department of Health
1224 Kinnear Road - Suite 120
Columbus, OH 43212
(614) 644-2727
1-800-523-4439 in state
n-30 Reprinted fiom USGS Open-File Report 93-292
-------
Oklahoma Gene Smith
Radiation Protection Division
Oklahoma State Department of
Health
P.O. Box 53551
Oklahoma City, OK 73152
(405)271-5221
Oregon George Toombs
Department of Human Resources
Health Division
1400 SW 5th Avenue
Portland, OR 97201
(503)731-4014
Pennsylvania Michael Pyles
Pennsylvania Department of
Environmental Resources
Bureau of Radiation Protection
- P.O. Box 2063
Harrisburg,PAT7l20
(717)783-3594
1-800-23-RADON In State
Puerto Rico David Saldana
Radiological Health Division
• G.P.O. Call Box 70184
Rio Piedras, Puerto Rico 00936
(809)767-3563
Rhode Island EdmundArcand .
Division of Occupational Health and
Radiation , ,.
" Department of Health
205 Cannon Building .
Davis Street
Providence, RI'02908
" (401)277-2438
South Carolina
Bureau of Radiological Health
Department of Health and ,
Environmental Control
2600 Bull Street
Columbia, SC 29201
(803)734-4631
1-800-768-0362
South Dakota MikePochop
Division of Environment Regulation
Department of Water and Natural
Resources '
Joe Foss Building, Room 217
523 E." Capitol
Pierre, SD 57501-3181
(605)773-3351
Tennessee Susie Shimek .
Division of Air Pollution Control
Bureau of the Environment
Department of Environment and
Conservation
Customs House, 701 Broadway
Nashville, TN 37219-5403
(615) 532-0733
1-800-232-1139 in state
Texas Gary Smith
Bureau of Radiation Control
Texas Department of Health
1100 West 49th Street
. Austin, TX 78756-3189
' (512) 834-6688 ,
Utah John Hultquist .
- Bureau of Radiation Control
Utah State Department of Health
.288 North, 1460 West
P.O. Box 16690
Salt Lake City, UT 84116-0690
(801) 536-4250
Vermont Paul demons
Occupational and Radiological Health
Division
Vermont Department of Health
10 Baldwin Street
Montpelier.VT 05602
(802) 828-2886
•1-800-640-0601 in state
Virgin Islands Contact the U.S. Environmental
Protection Agency, Region H
in New York
(212)264-4110 .
H-31 Reprinted from USGS Open-File Report 93-292
-------
Virginia Shelly Ottenbrite
Bureau of Radiological Health
Department of Health
109 Governor Street
Richmond, VA 23219
(804) 786-5932
1-800-468-0138 in state
Washington Kate Coleman
Department of Health
Office of Radiation Protection
Airdustrial Building 5, LE-13
Olympia, WA 98504
(206)753-4518
1-800-323-9727 In State
West Virginia Beattie L. DeBord
Industrial Hygiene Division
West Virginia Department of Health
151 llth Avenue
South Charleston, WV 25303
(304) 558-3526
1-800-922-1255 In State
Wisconsin Conrad Weiffenbach
Radiation Protection Section
Division of Health
Department of Health and Social
Services
P.O. Box 309
Madison, WI53701-0309
(608) 267-4796
1-800-798-9050 in state
Wyoming Janet Hough
Wyoming Department of Health and
Social Services
Hathway Building, 4th Floor
Cheyenne, WY 82002-0710
(307) 777-6015
1-800-458-5847 in state
11-32 Reprinted from USGS Open-File Report 93-292
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STATE GEOLOGICAL SURVEYS
' May, 1993
Alabama Ernest A. Mancini
Geological Survey of Alabama \
P.O. Box 0
420 Hackberry Lane '
Tuscaloosa, AL 35486-9780
(205)349-2852
Alaska Thomas E. Smith
Alaska Division of Geological;&
Geophysical Surveys
794 University Ave., Suite 200
Fairbanks, AK 99709-3645
(907)479-7147
Arizona Larry D. Fellows
- Arizona Geological Survey
845 North Park Ave,, Suite 100
Tucson, AZ 85719
(602) 882-4795
.Arkansas Norman F. Williams .
Arkansas Geological Commission
Vardelle Parham Geology Center
, 3815 West Roosevelt Rd.
Little Rock, AR 72204
(501)324-9165
California James F.Davis . .
California Division of Mines &
Geology \
801 K Street, MS 12-30
Sacramento^ CA 95814-3531
(916)445-1923
Colorado Pat Rogers (Acting)
Colorado Geological Survey
1313 Sherman St., Rm 715
Denver, CO 80203
(303)866-2611
Connecticut Richard C. Hyde ;
Connecticut Geological & Natural
History Survey
165 Capitol Ave., Rm. 553
Hartford, CT 06106
(203) 566-3540 ,
Delaware Robert R. Jordan
Delaware Geological Survey
University of Delaware
101 Penny Hall
Newark, DE 19716-7501
(302)831-2833 .
Florida Walter Schmidt
Florida Geological Survey
903 W.Tennessee S..
Tallahassee, FL 32304-7700
(904)488-4191
Georgia William H. McLemore
Georgia Geologic Survey
Rm. 400
19 Martin Luther King Jr. Dr. SW
Atlanta, GA 30334
(404)656-3214
Hawaii Manabu Tagomori ;
Dept. of Land and Natural Resources
Division of Water & Land Mgt
P.<3. Box 373
Honolulu, HI 96809
(808)548-7539
Idaho Earl H. Bennett
Idaho Geological Survey
University of Idaho _'• .
Morrill Hall, Rm. 332
Moscow; ID 83843
(208)885-7991 '
Illinois Morris W. Leighton
Illinois State Geological Survey
Natural Resources Building
615EastPeabodyDr.
Champaign, IL 61820
(217)333-4747
Tnrfiana Norman C. Hester
Indiana Geological Survey
611 North Walnut Grove
Bloomington, IN 47405
(812)855-9350
Iowa DonaldL.Koch
Iowa Department of Natural Resources
Geological Survey Bureau
109 Trowbridge Hall •
Iowa City, IA 52242-1319
(319) 335-1575
Kansas LeeC.Gerhard
Kansas Geological Survey
1930 Constant Ave., West Campus
University of Kansas
. Lawrenee,KS 66047
(913)864-3965
n-33 Reprinted from USGS Open-File Report 93-292
-------
Kentucky Donald C. Haney
Kentucky Geological Survey
University of Kentucky
228 Mining & Mineral Resources
Building
Lexington, KY 40506-0107
(606) 257-5500
Louisiana William E. Marsalis
Louisiana Geological Survey
P.O. Box 2827
University Station
Baton Rouge, LA 70821-2827
(504) 388-5320
Maine ' Walter A. Anderson
Maine Geological Survey
Department of Conservation
State House, Station 22
Augusta, ME 04333
(207)289-2801
Maryland Emery T. Cleaves
Maryland Geological Survey
2300 St. Paul Street
Baltimore, MD 21218-5210
(410) 554-5500
Massachusetts Joseph A. Sinnott
Massachusetts Office of
Environmental Affairs
100 Cambridge SL, Room 2000
Boston, MA 02202
(617) 727-9800
Michigan R. Thomas Segall
Michigan Geological Survey Division
Box 30256
Lansing, MI 48909
(517) 334-6923
Minnesota Priscilla C. Grew
Minnesota Geological Survey
2642 University Ave.
St Paul, MN 55114-1057
(612) 627-4780
Mississippi S. Cragin Knox
Mississippi Office of Geology
P.O. Box 20307
Jackson, MS 39289-1307
(601)961-5500
Missouri James H. Williams
Missouri Division of Geology &
Land Survey
111 Fairgrounds Road
P.O. Box 250
Rolla, MO 65401
(314)368-2100
Montana Edward T. Ruppel
Montana Bureau of Mines & Geology
Montana College of Mineral Science
, and Technology, Main Hall
Butte.MT 59701
(406)496-4180
Nebraska Perry B. Wigley
Nebraska Conservation & Survey
Division
113 Nebraska Hall
University of Nebraska
Lincoln, ME 68588-0517
(402)472-2410
Jonathan G. Price
Nevada Bureau of Mines & Geology
Stop 178
• University of Nevada-Reno
Reno, NV 89557-0088
(702) 784-6691
New Hampshire Eugene L.Boudette
Dept. of Environmental Services
117 James Hall
University of New Hampshire
Durham, NH 03824-3589
(603)862-3160
New Jersey Haig F. Kasabach
New Jersey Geological Survey
P.O. Box 427
Trenton, NJ 08625
(609)292-1185
New Mexico Charles E. Chapin
New Mexico Bureau of Mines &
Mineral Resources
Campus Station
Socorro.NM 87801
(505)835-5420
New York Robert H. Fakundiny
New York State Geological Survey
3136 Cultural Education Center
Empire State Plaza
Albany, NY 12230
. (518)474-5816
n-34
Reprinted from USGS Open-File Report 93-292
-------
North Carolina Charles H. Gardner
North Carolina Geological Survey
P.O. Box 27687
Raleigh, NC 27611-7687
(919)733-3833
North Dakota John P. Bluemle
North Dakota Geological Survey
. 600EastBlvd. ,
Bismarck, ND 58505-0840,
(701) 224-4109
Ohio Thomas M. Berg
Ohio Dept of Natural Resources
Division of Geological Survey
4383 Fountain Square Drive
Columbus, OH 43224-1362
(614)265-6576
Oklahoma Charles J. Mankin
Oklahoma Geological Survey
Room N-131, Energy Center
'• • ' 100E.Boyd
Norman, OK 73019-0628
(405)325-3031
Oregon Donald A. Hull
Dept of Geology & Mineral. Indust.
Suite 965
800 NE Oregon'St. #28
Portland, OR 97232-2162,
(503)731^600
Pennsylvania Donald M. Hoskins
Dept. of Environmental Resources
Bureau of Topographic & Geologic
Survey
P.O. Box 2357
Harrisburg, PA 17105-2357
(717)787-2169
Puerto Rico Ram6n M. Alonso.
Puerto Rico Geological Survey
''.-'. Division
Box 5887
Puerta deTierra Station
San Juan, P.R. 00906
(809). 722-2526
Rhode Island J. Allan Cain
Department of Geology
: University of Rhode Island
315GreenHall
Kingston, RI02881
(401)792-2265
South Carolina Alan-Jon W. Zupan (Acting)
South Carolina Geological Survey
5 Geology Road
Columbia, SC 29210-9998
(803) 737-9440
South Dakota C.M. Ghfistensen (Acting)
South Dakota Geological Survey
Science Center
University of South Dakota
Vermiffion, SD 57069-2390
(605)677-5227
Tennessee Edward T.Luther
-. Tennessee Division of Geology
13th Floor, L & C Tower
401 Church Street
Nashville, TN 37243-0445
. (615)532-1500,
Texas William L. Fisher ,
Texas Bureau of Economic Geology
-'• . University of Texas
University Station, Box X
Austin, TX 78713-7508
(512)471-7721
Utah M. Lee Allison
Utah Geological & Mineral Survey
2363 S. Foothill Dr.
Salt Lake City, UT 84109-1491
(801)467-7970
Vermont Diane L.Conrad
Vermont Division of Geology and
Mineral Resources
103 South Main St.
, , Waterbury.VT 05671
(802)244-5164
Stanley S. Johnson
Virginia Division of Mineral
Resources
P.O. Box 3667
Charlottesville, VA 22903
(804)293-5121
Washington Raymond Lasmanis
. Washington Division of Geology &
Earth Resources
Department of Natural Resources
P.O. Box 47007 ,
Olympia, Washington 98504-700?
(206)902-1450
n-35 Reprinted from USGS Open-File Report 93-292
-------
West Virginia Larry D. Woodfoik
West Virginia Geological and
Economic Survey
Mont Chateau Research Center
P.O. Box 879
Morgantown.WV 26507-0879
(304) 594-2331
"Wisconsin James Robertson
Wisconsin Geological & Natural
History Survey
3817 Mineral Point Road
Madison, WI 53705-5100
(608) 263-7384
Wyoming Gary B. Glass
Geological Survey of Wyoming
University of Wyoming
Box 3008, University Station
Laramie, WY 82071-3008
(307) 766-2286
11-36 Reprinted from USGS Open-File Report 93-292
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EPA REGION 2 GEOLOGIC RADON POTENTIAL SUMMARY
.... . : • by , - .
Linda C.S.Gundersen and R.Randall Schumann
. U.S. Geological Survey
EPA Region 2 includes the states of New Jersey and New York. For each state, geologic
radon potential areas were delineated and ranked on the basis of geologic, soil, housing
construction, and other factors. Areas in which the average screening indoor radon level of all
homes within the area is estimated to be greater than 4 pCi/L were ranked high. Areas in which
the average screening indoor radon level of all homes within the area is estimated to be between 2 ,
and 4 pCi/L were ranked moderate/variable, and areas in which the average screening indoor radon
level of all homes within the area is estimated to be less than 2 pCi/L were ranked low.
' Information on the data used and on the radon potential ranking scheme is given in the introduction
to this volume. More detailed information on the geology and radon potential of each state in
Region 2 is given in the individual state chapters. The individual chapters describing the geology
and radon potential of the states in EPA Region 2, though much more detailed than this summary,
are still generalized assessments and there is no substitute for having, a home tested. Within any
radon potential area, homes with indoor radon levels both abbve and below the predicted average
likely will be fourid. :
Figure 1 shows the geologic radon potential areas in Region 2, combined and summarized
from the individual state chapters in this booklet These areas are based on the major geologic
provinces in these states. Figure 2 shows average screening indoor radon levels by county. The
data for New York were compiled by the New York State Department of Health and data for New.
Jersey .were compiled by the New Jersey Department of Environmental Protection and Energy.
Figure 3 is a generalized geologic radon potential map of EPA Region 2,
NEW JERSEY ... , . .' .
The New Jersey Highlands have been ranked high in geologic radon potential. Screening
measurements of indoor radon in this area averaged 8.6~pCi/L. Uranium in rocks of the New
Jersey. Highlands is well documented in the literature. Uraninite and other U-bearing minerals
form layers and disseminations in several kinds of host rocks,-inpluding intrusive granitic rocks,
magnetite deposits, pegmatites, marble, veins, faults, shear zones, and feldspathic
metasedimentary gneiss. Soil permeability is generally moderate to high with a few areas of low
permeability. Glacial deposits in the New Jersey Highlands are, for the most part, locally derived
and, in some areas, they enhance radon potential because of high permeability. In other areas,
glacial deposits may blanket more uraniferous bedrock and effectively lower the radon potential.
The Valley and Ridge Province has .been divided into two sections for this assessment.
Silurian and Devonian rocks of the Valley and Ridge and the Green Pond outlier have been ranked
moderate in radon potential. The Silurian and Devonian rocks are predominantly conglomerate,
sandstone, shale, and limestone that generally have low to moderate equivalent uranium associated
with them. The shales and local uranium mineral accumulations in the sandstones are the most
likely source of radon problems. A few homes with indoor radon concentrations greater than
20 pCi/L were measured in the Silurian and Devonian rocks. —
m-1 Reprinted from USGS Open-File Report 93-292-B
-------
1 II
1 • --*
'
0
5.0
Miles
Figure 1. Geologic radon potential areas of EPA Region 2. 1-St. Lawrence-Champlain
Lowlands; 2-High Peaks; 3-Northwest Lowlands; 4-Adirondacks; 5-Tug Hill Plateau;
6-Erie-Ontario Lowland; 7-Hudson-Mohawk Lowland; 8-AUegheny Plateau; 9-New England
Upland-Taconic Mountains; 10-Manhattan Prong; 11-Aflantic Coastal Plain; 12-Valley and Ridge;
13-New Jersey Highlands-Hudson Highlands; 14-Triassic Lowland (NY)/northern Piedmont
); 15-southem Piedmont; 16-Inner Coastal-Plain; 17-Outer Coastal Plain.
-------
Screening Indoor Radon
Average Concentration (pCi/L)
0.0 to 1.9
2.0 to 4.0
4.1 to 9.9
10.0 to 14.8
Figure 2. Average screening indoor radon levels, by county, for EPA Region 2.
primarily from 2-7 day charcoal canister tests. Data for New York were compiled by the New
York State Department of Health; data for New Jersey were compiled by the New Jersey
Department of Environmental Protection and Energy. Histograms in map legend show the number
of counties in each category.
-------
GEOLOGIC RADON POTENTIAL
I I LOW(<2pCi/L)
E551 MODERATE/VARIABLE (2-4 pCi/L)
• HIGH (>4 pCi/L)
Figure 3. Generalized map showing geologic radon potential of EPA Region 2. For more detail
refer to the individual state geologic radon potential chapters.
-------
The Cambrian-Ordovician rocks of theValley and;Ridge have been ranked high in geologic
radon potential; The Hardyston Quartzite is known to have local uranium and uranium mineral
' 'deposits and the black shales and carbonate soils are also sources of indoor radon. Screening
measurerhents of indoor radon in the VaTey and Ridge averaged 7.6 pCi/L. Equivalent uranium is
generally moderate to high over, the Cambrian and Ordovician sedimentary rocks. Soil
permeability is generally moderate. ' ,
The, northern and southern Piedmont provinces together form the Newark B.asin. The
basin is underlain by Triassic sandstone, siltstones, and shales; Jurassic basalt and diabase; and
Jurassic siltstone, shales, and sandstones. Of all these rock types, the black shales have the
greatest potential to be a source of radon problems. Black shales are not as abundant in the
northern Piedmont as in the southern Piedmont The average screening indoor radon level in the
northern Piedmont is 1.7 pCi/L; indoor radon levels greater than 4 pCi/L are probably associated
with the black shales of the lower Passaic Formation and uranium mineralization along the northern
border fault and in adjacent rocks. Sands and conglomerates of the upper Passaic Formation with
low geologic radon potential dominate the northwestern part of the northern Piedmont. Jurassic
basalts and interbedded sands and shales with low to moderate radon potential make up the western
half of the northern Piedmont Low to moderate radon potential is expected for the eastern half of
the northern Piedmont, which is .underlain by sands interbedded with lacustrine shales of the
Passaic Formation and diabase of the Palisades sill that intrudes along the Lockatong Formation-
Stockton Formation contact This thin layer of Lockatong Formation may be responsible for the
'single indoor radon level greater than 20 pCi/L found near here. The northern Piedmont has been
ranked low in geologic radon potential overall. The southern Piedmont is underlain by the
uraniferous black shales and siltstones of the lower Passaic Formation, the uraniferous black
shales of the Lockatong Formation, and the uraniferous black shales and locally uraniferous
sandstones of the Stockton Formation. Average indoor radon for the southern Piedmont is
4.9 pCi/L. Equivalent uranium is also moderate to high. Soil permeability is low to moderate.
The southern Piedmont has been ranked high in geologic radon potential.
The Inner Coastal Plain Province, underlain by Cretaceous and Early Tertiary sediments, is
ranked moderate in radon potential. Screening measurements of indoor radon in the Jjmer Coastal
Plain averaged 2.4 pCi/L. Equivalent uranium is generally moderate. Soil permeability is
moderate to high. Soil radon studies indicate that the glauconitic sediments are significant sources
of radon. The highest soil radon concentrations and radioactivity were found in the glauconitic
sands of the Cretaceous Englishtown and Navesink Formations, the Mount Laurel Sand, and the
Tertiary Hornerstown Sand. .
The Outer Coastal Plain has been ranked low in radon potential. Soil radon studies of the
Tertiary Kirkwood Formation, Cohansey Sand, and Pleistocene residuum indicate that they are
relatively poor sources of radon. Equivalent uranium is generally.low. Soil permeability is
moderate to high and the average indoor radon for the province is low (1.4 pCi/L).
NEW YORK
The Erie-Ontario Lowland and Tug Hill Plateau are underlain by a flat-dying sedimentary
sequence with abundant limestone, dolomite, shale, sandstone, and distinctive salt deposits.
Counties in the Erie-Ontario Lowland generally have indoor radon geometric means of less than
2 pCi/L and average indoor radon concentrations of less than 4 pCi/L. A veneer of impermeable
' clay covers a significant portion of the Erie-Ontario Lowland and generates low to moderate indoor
m-5 Reprinted from USGS Open-File Report 93-292-B
-------
radon levels. Discrete occurrences of very coarse gravel and some marine shales may cause some
of the moderate and locally high radon levels found in the area. Although the Erie-Ontario
Lowlands have low radon source strength, low permeability, and consequently low radon
potential, radon potential is high in association with gravels in drumlins, outwash, moraines, till,
and beach ridges in the region. Significant accumulations of these coarse glacial deposits occur in
Wayne County and in the eastern portion of the province around the Tug Hill Plateau. We have
assigned an overall moderate/variable radon potential to the area based on the majority of county
indoor radon averages being greater than 2 pCi/L, the variably low to high radon source potential
of the underlying geology, variably low to high soil permeability, and low (<1.5 ppm eU) to
moderate (1.5-2.5 ppm ell) radioactivity. .
The Hudson-Mohawk Lowland is underlain by sandstone, siltstone, shale, and
conglomerate of variable ages. In this assessment, the lowland has been ranked generally
moderate or variable in radon potential, as the geology and glacial deposits of the area are highly
variable and radon potential varies likewise from low to high. Equivalent uranium is generally
moderate to locally high (>2.5 ppm eU) in this area. Soils have moderate to locally high
permeability. The region is underlain predominantly by shale with average to below-average
radium concentrations and indoor radon over the shale is generally low. High levels of indoor and
soil radon are associated with gravelly kame and till deposits found above valley bottoms and with
gravel concentrations in sandy glacial deposits, generally moderate radon levels are associated with
lacustrine delta and kame deposits, and generally low levels are associated with Recent floodplain
deposits, lacustrine silt and clay, lacustrine sand, and dune sand.
The St. Lawrence and Champlain Lowlands are underlain by sedimentary rocks of
Cambrian through early Ordovician age with relatively low geologic radon potential. However,
some of the very coarse gravel deposits have moderate to high radon potential. Equivalent uranium
is generally low with a few moderate areas. Counties in the lowlands have indoor radon geometric
means less than 2 pCi/L and basement average concentrations of indoor radon less than 3 pCi/L. A
veneer of impermeable clay covers much of the area; however, areas of highly permeable, very
coarse glacial gravels and gravel in beach ridges may cause some of the moderate to high radon
levels found in the area. Local occurrences of elevated (>4 pCi/L) indoor radon are associated with
gravels in drumlins, outwash, moraines, till, and beach ridges. Because of these highly permeable
deposits and county average radon greater than 2 pCi/L, these provinces have been ranked
moderate in radon potential.
The Allegheny Plateau is underlain by sedimentary rocks, predominantly shales,
limestones, and sandstones. Soils in the southern part of the plateau have low to moderate
permeability except for glacial gravel deposits, primarily in valleys, which have high permeability.
In the northern plateau, the soils have low permeability, with the exception of local glacial gravels.
The plateau has been ranked high in radon potential overall. However, parts of the Allegheny
Plateau are low to moderate in radon potential, especially areas in the CatsMll Mountains.
Equivalent uranium is generally moderate in the plateau and is high along the south-central border
with Pennsylvania. The radioactivity pattern may correspond to the geometry of the Valley Heads
Moraine in the Finger Lakes region, with thinner till and progressively higher radioactivity south of
the moraines. The central and southern parts of the plateau have high radon potential in association
with coarse kame, till, and other gravel deposits which are generally restricted to valleys. Two
belts of uraniferous black shale, the Marcellus Shale and West Falls Group shales, cross central
and southern New York and cause significant high indoor radon from Onondaga County to Erie
County. Other black shales and related sedimentary rocks in the plateau do not appear to have as
m-6 Reprinted from USGS Open-File Report 93-292TB
-------
high uranium contents. Elevated indoor radon concentrations near the contact between the
Onondaga limestone and the Marcellus Shale may be du&to remobffization of uranium from the
shale into the fractured limestone. Of the northern counties in the Allegheny Plateau, only Seneca
County has an indoor radon average less than 4 pCi/L and it is considered to have moderate radon
potential. The northern, more populous portion of Seneca County is underlain by glacial clays and
the rest of the county is covered by till. Gravelly glacial deposits are the cause of most of the high
radon found in the southern plateau, probably due to high permeability and high radon emanation
coefficients. Because the alluvial valley and moraine deposits are discrete bodies, categorizing.
whole counties as high in radon potential may not be accurate. In addition, many towns are built in
the valleys, on the deposits most likely to cause high radon, and most of the indoor radon data
available for the counties is from these towns. Further work is needed outside of the towns located
in the .valleys to accurately evaluate the uplands and counties as a whole. Because many of the
• uplands are underlain by highly fractured shales, there is a geologic potential for elevated indoor
radon. Most counties in the Allegheny Plateau have indoor radon geometric means in the 2-4 •.<.
pCi/L range and county averages greater than 4 pCi/L. Four counties-Allegany, Chemung,
Cordand, and Steuban-have county indoor radon averages greater than 10 pCi/L. Sullivan
County, which is mostly located in the Catskill Mountains, has lower indoorradon than
surrounding counties with an average of 3.1 pCi/L and geometric mean of 1.7 pCi/L: This county
is considered to be moderate in radon potential.
The Hudson Highlands, which are the northeastern extension of the Reading Prong, have
been ranked high in radon potential, but the radon potential is actually highly variable. These
mountains consist of a wide variety rock types. Equivalent uranium is generally moderate with
local lows arid highs. Soils are thin and stony with locally thick accumulations of low-permeability
till. Numerous uranium localities and associated gamma-radioactivity anomalies are well
documented in the Hudson Highlands. These uranium deposits appear to be the cause for localized
occurrences of very high indoor radon levels. Faults and shear zones in the Highlands also host
uranium mineralization arid are well known throughout the Appalachians for causing high indoor
radon levels. Faults may also be an important radon source in parts of the Adirondacks and New
England Upland. Rock types which tend to be low in uranium in the Hudson Highlands include
amphibolitic gneisses, quartz-poor gneisses, and some marbles. Because the composition and
location of very high uranium concentrations in these rocks is so variable, indoor radon is highly
variable. The Hudson Highlands underlie parts of Putnam and Orange Counties, which have
county indoor radon geometric means of 2.4 and 2.8 pCi/L respectively, and county indoor radon
averages greater than 4 pCi/L. The Hudson Highlands are high in radon potential because of the
very high indoor radon levels found in some homes, because'rnany of the homes are built into
bedrock, and because high levels of radon in well-water also occur.
The Manhattan Prong is made up of metamorphic and igneous rocks with generally low
amounts of uranium and low radon potential. No .direct correlation between any of the.Manhattan
Prong rocks and indoor radon has been made. Equivalent uranium is generally low to moderate.
Soils have low to moderate permeability. Counties underlain by the Manhattan Prong (Westchester
County and most of New York City) have indoor radon geometric means £ 1.5 pCi/L and average
indoor radon < 2.4 pCi/L.
The New England Uplarid-Taconic Mountains area is underlain predominantly by slate,
phyllite, graywacke, and limestone. This area has been ranked high in radon potential. The
courity geometric means for indoor radon in this province are greater than 2 pCi/L and the county
averages are greater than 4 pCi/L. Equivalent uranium is moderate to locally high. Soil
ffl-7 Reprinted ftomUSGS Open-File Report 93-292-B
-------
permeability is low to moderate, with locally high permeability in glacial gravels. High indoor
radon levels appear to be related to highly permeable glacial and fluvial sediments along the
valleys. .
The High Peaks and most of the central Adir^" -'-s are made up of anorthosite and
gneiss, both of which are low in uranium and unlikely to cause radon problems. The rim of the
Adirondacks is composed predominantly of metasedimentary and metavolcanic rocks, several of
which contain local uranium occurrences and have locally high radon potential. Equivalent
uranium in the Adirondacks is low over the High Peaks and surrounding charnockitic rocks.
Moderate and locally high equivalent uranium is associated with the Northwest Lowlands and
scattered areas in metasedimentary rocks and iron deposits in the southeastern and eastern rim of
the Adirondacks. Soils have low to moderate permeability with locally high permeability in sandy
and gravelly glacial deposits. Most counties in the Adirondack Mountains have geometric means
of indoor radon less than 2 pCi/L. Average indoor radon is < 1.5 pCi/L in Essex, Hamilton, and
Franklin Counties, but greater than 2 pCi/L for Herkimer, Warren, St. Lawrence, and Lewis
Counties. These counties also lie partially in other geologic provinces. We rank the High Peaks
and Adirondacks low in radon potential but rank the Northwest Lowlands moderate in radon
potential due to the high radioactivity, local occurrence of uranium, local glacial gravel deposits,
the sheared and faulted metamorphic rocks, and higher indoor radon in St Lawrence County.
In the Valley and Ridge section, sedimentary rocks of Cambrian through Ordovician age
comprise the underlying bedrock and have been ranked high in radon potential but may be locally
low to moderate. Cambrian and Ordovician rocks consist of a marine shelf sequence with basal
Cambrian sandstones and conglomerates followed by a highly variable sequence of interbedded
shales and carbonate rocks. Many of the black shales in this sequence are elevated in uranium (>2 •
ppm) and, although the limestones are relatively low in uranium, the local residual soils formed on
limestones in the valleys of the area may be elevated in uranium. Indoor radon is elevated
(> 4 pCi/L) in basements of homes built on limestone soils of the Wallkill Valley, on black shale
bedrock, and especially in glacial gravel deposits containing black shale.
The Triassic Lowland is underlain by fluvial quartz sands, minor siltstones-and shales, and
Jurassic basalt and diabase, and underlies most of Rockland County. Of these rock types, the
shales have the potential to be a source of radon problems; however, they are not abundant. Black
shales and gray sandstones in the lower Passaic Formation are similar to uranium-bearing units in
the same formation in New Jersey, but they make up a minor part of the section. Rockland County
has a basement indoor radon average of 2.2 pCi/L and a geometric mean of 1.3 pCi/L. Equivalent
uranium is low to moderate for the Triassic Lowlands. Soil permeability is generally low to
moderate. The Triassic Lowlands have been ranked low in radon potential.
'Long Island, in the Atlantic Coastal Plain Province, is made up of glacial deposits and
marine sediments containing little or no uranium. Indoor radon measurements are among the
lowest in the State. Counties of the Atlantic Coastal Plain have indoor radon geometric means less
than 2 pCi/L and average concentrations of indoor radon less than 2 pCi/L. Permeability is
moderate to high with local areas of low permeability. A number of boulders in the glacial
moraines on Long Island have high levels of radioactivity and coarse gravels and sands of the
glacial outwash may also have isolated uranium concentrations, making them local sources of
elevated radon.
m-8 Reprinted from USGS Open-File Report 93-292-B
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PRELIMINARY GEOLOGIC RADON POTENTIAL ASSESSMENT OF NEW JERSEY
• ,-..•-•'' * ... by •..•> •'.• -• - " ' ,.-
Linda CS.Gundersen and R.Randall Schumann •
U.S. Geological Survey ..
INTRODUCTION . , .,
In 1986, the New Jersey Department of Environmental Protection and Energy (NJDEPE)
initiated the Statewide Scientific Study of Radon. In this comprehensive study, over 6000 homes
and buildings were sampled for indoor radon and an extensive database of geologic, soil, political,
demographic, meteorological, building features, and resident behavior information was collected
and compared with the indoor radon data (Camp Dresser and McKee Inc., 1989). Models for
radon potential and risk exposure were also developed from these data. Since the completion of •
that studyrthe NJDEPE has also compiled a separate indoor radon database which now includes
151,453 individual measurements. The State of New Jersey has classified all
municipalities of the state as having high, moderate, or low potential for elevated
radon based on this database. State law requires that residential and school
structures built in municipalities that the State has classified with a high radon
potential use construction techniques that minimize radon entry and facilitate
post-construction removal of radon. Please contact the New Jersey Radon
Program at 800-648-0934 (New Jersey only) or 609-987-6396 for information.
The NJDEPE study found the highest average indoor radon levels in the New Jersey
Highlands and the Valley and Ridge. More than half of the indoor radon measurements in these
two provinces exceeded 4 pCi/L. The Southern Piedmont also had high average indoor radon
(4.9pCi/L). In every province of the State atleast 5 percent of the readings were 4 pCi/L or '
more, and at least one home in every province had indoor radon levels exceeding 30 pCi/L. The
study found that geology exerts a strong influence on indoor radon and that aerial radiometric data
provide very good correlations with indoor radon. When the data collected in the NJDEPE study
and the updated indoor radon database are analyzed using the geologic radon indexes developed by
the U.S. Geological Survey (USGS) for the U.S. Environmental Protection Agency (EPA) the
results are very similar. The Cambrian-Ordovician sedimentary rocks of the Valley and Ridge, the
gneisses of the New Jersey Highlands, and the Triassic sedimentary rocks of the S outhern
Piedmont score high in radon potential. The Cretaceous and Lower Tertiary sediments of the Inner
Coastal Plain and the Silurian-Devonian, sedimentary rocks of the Valley and Ridge and the New
Jersey Highlands score moderate in radon potential. The Northern Piedmont is highly variable,
generally low to moderate in radon potential, with a few locally high areas in the Lockatong and
Lower Passaic Formations. The Tertiary and Quaternary sediments of the Outer Coastal Plain
score low in radon potential. - -
The scale of the USGS assessment is such that it is inappropriate for use in identifying the
radon potential of small areas such as neighborhoods, individual building sites, or housing tracts.
Within any area of a given radon potential ranking, there are likely to be areas with higher or lower
radon levels than characterized for the area as a whole. Indoor radon levels, both high and low,
can be quite localized, and there is no substitute for testing individual homes. Elevated levels of
indoor radon have been found in every State, and EPA recommends that all homes be tested.1
IV-1 Reprinted from USGS Open-File Report 93-292-B
-------
PHYSIOGRAPHIC AND GEOGRAPHIC SETTING
The physiography of New Jersey (fig. 1) is in part a reflection of the underlying bedrock
geology (fig. 2). New Jersey has four major physiographic regions: The Appalachian Valley and
Ridge Region; The New Jersey Highlands; the Piedmont; and the Atlantic Coastal Plain. The
•Valley and Ridge Province covers 635 square miles in the northwestern part of the State. It is
characterized by a series of parallel ridges and valleys that trend in a northeast-southwest direction.
The ridges are frequently underlain by sandstones and conglomerates, whereas the valleys are
underlain by limestones and shales. Elevation rises to more than 1800 feet above sea level at
Kittatinny Mountain. The New Jersey Highlands Province (also known as the Reading Prong)
covers about 900 square miles of rugged, mountainous terrain. It is underlain by Precambrian
igneous and metamorphic rocks as well as inliers of Lower and Middle Paleozoic sedimentary
rocks. The highest elevation in the Highlands is 1496 feet in the north.neaf Vernon, while some of
the intermontane valleys are as low as 200 feet above sea level. The Piedmont Lowland Province
lies just southeast of the Highlands (fig. 1) and covers 1500 square miles of broad piedmont plain
and rolling lowland. The highest elevation is 879 feet in the basaltic ridges of the Watchung
Mountains. The average elevation of the Piedmont is between 200 and 400 feet above sea level.
The Coastal Plain Province covers over, three-fifths (4500 square miles) of the State. It is a broad,
belted plain that slopes gentry towards the Atlantic Ocean. This province is bounded to the north
by the "fall line" where it intersects the Piedmont, the fall line is marked by a distinct change in
water velocity and by waterfalls along the stream and river drainages, giving the boundary its
name. Relief is low and elevation is less than 200 feet above sea level. Cuestas, or ridges of more
resistant sediments, give the Coastal Plain a distinctive topography.
In 1990, the population of New Jersey was 7,730,188, including 89 percent urban
population (fig. 3). The population density is approximately 991 per square mile. The climate is
moderate and precipitation averages 46 to 50 inches per year (fig. 4).
GEOLOGIC SETTING
A generalized geologic map of New Jersey is shown in figure 2 (New Jersey Geological
Survey, 1984). The following descriptions are intended to present a general overview of the
geology of New Jersey and are derived from a number of sources, including numerous papers in
Subitzky (1969) and in Kroll and Brown (1990); Wolfe (1977); Drake (1984); Drake and others
(1990); Volkert and Drake (1990); and.Smoot (1991). The New Jersey Geological Survey is
currently completing a series of new geologic maps covering the entire State. It is recommended
that the reader refer to these new maps and other detailed geologic maps and information available
from the New Jersey Geological Survey (Dombroski, 1990; Harper, 1991).
The Coastal Plain Province '•'...
The Coastal Plain is underlain by Cretaceous and Tertiary marine and fluvial sand, clay, and
gravel forming a clastic wedge that thickens seaward. The surface expression of the gently dipping
Cretaceous and lower Tertiary sediments is a series of northeast-trending belts with the oldest belt
to the northwest and progressively younger belts southeastward. In the eastern part of the
province, the latest Tertiary deposits form sheets covering the older sediments that are irregularly
eroded to expose the underlying deposits.
IV-2 Reprinted from USGS Open-File Report 93-292-B
-------
Figure 1. Physiographic provinces of New Jersey.
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GENERALIZED GEOLOGIC MAP OF NEW JERSEY
EXPLANATION
SEDIMENTARY ROCKS
i ' . . . i
, Holocene: beach and estuarine deposits
Tertiary: sand, greensand, marl, and clay
Cretaceous: sand, clay, greensand, a'nd marl
Jurassic: siltstone, shale, sandstone, and conglomerate
Tri.assic: siltstone; shale, sandstone, and conglomerate
Devonian: conglomerate; sandstone, shale, and limestone
Silurian: conglomerate, sandstone, shale, and limestone
Ordovician: shale and sandstone
Gambrian-Ordovician: limestone and sandstone
IGNEOUS AND METAMORPHIC ROCKS
Jurassic: basalt ,
Jurassic: diabase
Precambrian: marble
Precambrian: gneiss and granite
-------
POPULATION (1990)
El 0 to 50000
0 50001 to 100000
E3 100001 to 250000
M 250001 to 500000
• 500001 to 825380
Figure 3. Population of counties in New Jersey (1990 U.S.: Census data).
-------
w-
s ,
10
20 30
Figure 4. Average annual precipitation in New Jersey (from Facts on File, 1984).
-------
The oldest Cretaceous sediments are fluvial and shallow marine interbedded sand and
variegated clayey silt and silty clay of the Raritan Formation, which form a broad band of outcrop.
The Raritan Formation is overlain by a series of fine-grained marine deposits that form narrow
outcrop belts, including fossihferous, locally glauconitic, clayey silt and sand of the Magothy
Formation; black, sandy glauconitic clay and local fine glauconitic sand of the Merchantville Clay;
and fossiliferous, gray to black clayey silt of the Woodbury Clay. The fine-grained marine
sequence is overlain by an upward-coarsening marine to fluvial sequence of the Englishtown
Formation that forms a narrow outcrop belt. To the north, the Englishtown consists of cross-
stratified sands, in places gravelly, interbedded with carbon-rich silt, and to the south it consists of
marine gray, fossiliferous silty sand. Glauconite lentils and siderite concretions are common near
the top. The Englishtown is overlain by an upward-coarsening sequence of marine clay to sand
composed of the Marshalltown and Wenonah Formations and Mount Laurel Sand. The
Marshalltown is a silty, glauconitic clay with fine quartz sand interbeds; the Wenonah is a fine,
micaceous silty sand that is slightly glauconitic; and the Mount Laurel Sand is a fine to coarse
quartz sand that is slightly glauconitic. The Navesink Formation is a coarse-grained, clayey,
glauconitic sand that is locally shelly at the base, and it overlies the Mount Laurel Sand. The
Navesink Formation is overlain by an upward-coarsening sequence of the Red Bank Sand that
forms a broad outcrop belt in the north-central part of the province and pinches out in the central
part of the province. The base of the Red Bank is dark-gray, fossiliferous silty sand that is locally
cemented with iron oxide. The Red Bank grades up into a slightly glauconitic quartz sand, and
glauconitic, sideritic sand of the Tinton Sand. In Gloucester and Salem Counties, the Red Bank
and Tinton Sands grade into a glauconitic, clayey and silty sand of the New Egypt Formation.
The lower Tertiary deposits are glauconitic sand similar to those of Cretaceous age, whereas:
the upper Tertiary is characterized by quartz sand. The Hornerstown Sand is the basal Tertiary unit
that forms a continuous narrow outcrop band consisting of fine- to coarse-grained, locally clayey,
glauconitic sand. The Hornerstown is overlain by the Vincentown Formation, which forms a
narrow outcrop band that becomes broader in the east-central part of the province. The
Vincentown is predominantly quartz sand that is glauconitic near the base. To the south, the lower
part of the Vincentown is a fossiliferous, glauconitic sand that grades upward into a calcareous
quartz sand. Glauconitic sand and mud of the Manasquan and Shark River Formations
discontinuously overlie the Vincentown. The Kirkwood Formation overlies the Manasquan, Shark
River, and Vincentown, and comprises a broad outcrop band that narrows to the southwest The
Kirkwood is a cross-bedded, locally conglomeratic, marine quartz sand with lenses of dark
porcelaneous phosphatic clay. The Cohansey Sand overlies the Kirkwood and comprises about
one-third of the Coastal Plain, forming a broad sheet to the south and irregular erosional remnants
on the Kirkwood to the north. To the north, the Cohansey consists of fluvial and marine, cross-
bedded quartz sand and gravelly sand, whereas to .the south it is composed of quartz sand
interbedded with thick dark-gray clay. .
New Jersey Highlands
The Reading Prong of the New Jersey Highlands is underlain by the oldest rocks in New
Jersey, consisting of approximately equal parts of metavolcanic, metasedimentary, and granitic
intrusive rocks.
At the base of the section is the Losee Metamorphic Suite which generally consists of rocks
dominated by sodic plagioclase and quartz with locally abundant biotite and minor hornblende,
magnetite, augite, and hypersthene. Texture of the rocks varies from massive to well-layered and
IV-8 Reprinted from USGS Open-File Report 93-292TB
-------
foliated. Pegmatite and amphibolite layers are sparse to moderately common. The Losee
Metamorphic Suite is thought to be partly metavolcanic in origin and contains probable
trondhjemitic to tonalitic intrusions. The Losee is distributed throughout the New Jersey
Highlands, especially in the central and eastern sections. Physically overlying the Losee
Metamorphic Suite is a sequence of metasedimentary rocks varying from calcareous to quartzp-
feldspathic in composition. The calcareous metasedimentary rocks include calcitic and dolomitic
marble, pyroxene gneiss, epidote-bearing gneiss, and variable gneisses containing pyroxene,
scapolite, arid allanite. The Franklin Marble crops out along the northern border of the New Jersey
Highlands, is the largest area of marble in the Highlands, and hosts well-known zinc deposits.
The metasedimentary quartzo-feldspathic rocks vary in composition, commonly containing biptite
and various amounts of garnet, graphite, sillimanite, and magnetite. Amphibolite and magnetite
deposits are locally associated with all of the above rock units. Metasedimentary rocks are most
abundant in the northern and western parts of the New Jersey Highlands.
Igneous intrusive rocks in the New Jersey Highlands are dominated by the Byram Intrusive
Suite and the Lake Hapatacong Intrusive Suite, and are distributed throughout the Highlands,
These two intrusive suites are granitic, syenitic, or monzonitic in composition arid consist of
varying amounts of quartz, several kinds of feldspar, and minor mafic minerals, predominantly
hornblende and clinopyroxene, respectively. Quartz-poor rocks of the Lake Hapatacong Suite are
monzonitic, and are common in north-central New Jersey.
Several kinds of migmatitic rocks not belonging.to the Byram Intrusive Suite are found
throughout the Highlands, but seem more abundant in north-central New Jersey. Charnockitic
rocks are widely distributed in the Highlands, but are most abundant in north-central New Jersey.
these rocks appear granitic, but often have distinct alternating light and dark layers, as well as
discontinuous layers of arnphiboHte.
Along the central axis of the New Jersey Highlands is an area of Devonian and Saurian
sandstones, shales, siltstones, minor carbonates, and conglomerates referred to as the Green Pond
outlier (Herman and Mitchell, 1989). The most prominent units include the Silurian Green Pond
Conglomerate, Longwood Shale, carbonates of the Poxono Island and Berkshire Valley
Formations, the Devonian Connelly Conglomerate, shales of the Esppus Formation, Kanouse
Sandstone, Cornwall Shale, BeUvale Sandstone, and Skunnemunk Conglomerate.
Appalachian Vallev and Ridge Province
The VaUey and Ridge is underlain by northeast-southwest trending belts of limestone, shale,
and sandstone. 'Along the contact with the Reading Prong, faults and folds complexly join rocks
characteristic of the two regions, maidng the boundary poorly defined.
The oldest rocks of the Appalachian VaUey and Ridge are Cambrian in age. These form a
series of narrow, fault-repeated belts along the southeastern edge of the province. The basal
Hardyston Quartzite and the overlying interbedded dolomite and phyllite of the Leithsville
Formation form very narrow bands. Most of the area is underlain by Cambrian rocks, including a
broad central belt of rocks called the Ailentown Dolomite.
Ordovician rocks form a broad belt covering the eastern half of the Valley and Ridge. The
basal Ordovician is composed of very narrow belts of limestone and dolomite of the Beekmantown
Group, including the S tonehenge Formation, Rickenbach Formation, Epler Formation, Ontelaunee
Formation, and the Kittatinny Supergroup. The Beekmantown Group is overlain by sandy and
clayey limestone of the Jacksonburg Limestone, which forms a series of very narrow outcrop
IV-9 Reprinted from USGS OpeibFile Report 93-292-B
-------
belts. Most of the Ordovician outcrop area is underlain by Martinsburg Formation, consisting of
black shale with interbeds of graywacke, sandstone, and siltstone.
The Silurian rocks form an outcrop belt parallel to the northwestern edge of the province
comprising narrow bands of progressively younger units. The basal Shawangunk Formation
unconformably overlies the Ordovician Martinsburg Formation and consists of fluvial quartz
conglomerate grading up'into deltaic sandstone and siltstone. This is overlain by red sandstone,
siltstone, and shale of the Bloomsburg Redbeds. This is overlain by green to gray shale with
sandstone and limestone interbeds of the Poxono Island Formation, followed by clayey limestone
of the Bossardville Limestone. The Bossardville is overlain by calcareous quartz sandstone,
siltstone, and limestone of the Decker Formation. Interbedded clay-rich limestone and dolomite
and calcareous shale of the Rondout Formation comprise the youngest Silurian rocks.
The Devonian rocks of the Valley and Ridge in New-Jersey are restricted to a belt along the
northwest margin of the province, forming narrow bands of formations. The basal part of the
section is limestone, clayey or shaly limestone, and calcareous shale of the Helderburg Group,
including the Coeymans and New Scotland Formations, the Minnisink Limestone, and the Port
Ewen Shale. The Helderburg Group is overlain by the Oriskany Group, consisting of silty
limestone of the Glenarie Formation, the Shriver Chert, and the Ridgely Sandstone. The Glenarie
Formation is the only unit found to the northeast, whereas the Ridgely Sandstone and Shriver
Chert dominate in the southwest The Oriskany Group is overlain by gray to black siltstone and
calcareous siltstone of the Esopus and Schoharie Formations. Limestone and shaly limestone of
the Buttermilk Falls Limestone overlie these units. The uppermost rocks are black shale of the
Marcellus Formation.
Piedmont (Newark Basin")
Late Triassic-early Jurassic continental sedimentary and igneous rocks of the Newark
Supergroup are restricted to the Newark basin, Which forms a broad northeast-trending belt across
the north-central part of the State. The Newark basin is a half graben with a faulted northwestern
margin. The strata dip toward the border fault and are folded into a broad syncline that extends
eastward into New York and another syncline near the Pennsylvania border that extends westward
into Pennsylvania. The stratigraphic sequence of the basin is repeated in two fault blocks that
extend into Pennsylvania. The basal Triassic Stockton Formation forms a narrow band along the
southeastern side of the basin and is repeated in the two fault blocks. The Stockton consists of
fluvial arkosic sandstone, siltstone, and conglomerate. It is more conglomeratic along its basal
contact with older rocks on the southeastern margin of the basin. The Stockton is overlain by the
Triassic Lockatong Formation, which forms a very narrow band in the northeastern part of the
basin and pinches out. The Lockatong forms broader bands to the southwest, where it is repeated
in the fault blocks. The Lockatong consists of lacustrine black and red shales and siltstones with
interbedded arkosic sandstones. The Triassic to Jurassic Passaic Formation overlies the Lockatong
and forms a broad belt of outcrop that underlies most of the basin in New Jersey. The Passaic
consists of red and black lacustrine shale and siltstone intertounging with sandstone and
conglomerate. The Passaic Formation is overlain by a Jurassic sequence of thpleiitic basalt flows
and sedimentary rocks, deformed by synclines along the border fault, and in fault slices that repeat
the stratigraphic section. The Jurassic sequence consists of the Orange Mountain Basalt, Feltville
Formation, Preakness Basalt, Towaco Formation, Hook Mountain Basalt, and Boonton
Formation. The Feltville, Towaco, and Boonton Formations consist of lacustrine black and red
shales interbedded with sandstones. The basalts and the Feltville and Towaco Formations form
IV-10 Reprinted from USGS Open-File Report 93-292-B
-------
narrow outcrop bands, but the Boonton underlies an extensive area in the core of the large syncline
along the border fault. Along the northwestern faulted margin of the basin, all of the formations
intertongue with alluvial fan conglomerates containing clasts of the older rocks immediately outside
of the basin. Jurassic diabase dikes and sheets intrude the sedimentary rocks. The most prominent
diabase body is the Palisades sill, which intrudes approximately along the contact of the Stockton
and Lockatong Formations near the Hudson River. It also forms a large sheet that intrudes along
the contact Of the Lockatong and Passaic Formations near the Delaware River. Smaller diabase
sheets are folded into syncliries along the fault contacts. , . .
GLACIAL GEOLOGY
* ' ' ' ',. -
Glacial deposits of pre-Dlihoian, Dlinoian, and Wisconsinan ages occur in northern New
Jersey (Fullerton, 1986; Stone and others, 1989). The Wisconsinan terminal moraine forms a
nearly continuous ridge of thick till across the State from Perth Amboy north to Denville and west
to Belvidere (Minard and Rhodehamel, 1969). Pre-Ulinqian and niinoian-age glacial deposits
isouth of the moraine are generally discontinuous and weathered to a much greater extent than the
Late Wisconsinan glacial deposits north of the moraine (Minard and Rhodehamel, 1969). Late
Wisconsinan till underlies much of the landscape north of the terminal moraine.
Glacial deposits in New Jersey are divided into three main classes: till, glaciofluvial
deposits, and glaciolacustrine deposits (fig. 5). Till is a nOn-stratified deposit consisting of a
poorly sorted mixture of sand, silt,-clay, and some gravel. Thickness of till in northern New
Jersey ranges from zero to as much as 76 m, but is generally less than 6 m. Till thickness averages
less than 1 m on uplands and 1-3 m beneath stratified meltwater deposits in valleys, and bedrock is
exposed in many places. Till is commonly more than 30 m thick in drumlins in the Newark Basin
area and the Great Valley and 6-20 m thick on the terminal moraine (B.D. Stone, personal
communication, 1993). The composition of .the till generally reflects the underlying bedrock,
although boulders from more distant source areas, called erratics, occur in all glaciated areas. In
the Valley and Ridge province, much of the glacial deposits are composed of shale, slate, and
graywacke in the valleys, and sandstone and conglomerate on many of the ridgetops. Limestone
and dolostone are a major components of the tills in carbonate valleys such as Kittatinny Valley ,
(Wolfe, 1977). In the Highlands, Precambrian gneiss is the major source component of the tills.
In.the Piedmont,- the tills are derived primarily from shale, sandstone, conglomerate, basalt, and
. diabase of the Triassic Newark Group (Minard and Rhodehamel, 1969).
Glacial landf orms associated with till include drumlins and moraines. Moraines are broad
ridges of till that form at the margin of a glacier. A terminal moraine averaging 1.5 km in width
and from 8 to 90 m high extends from Perth Amboy north to Denville and west to Belvidere. To
the north, recessional moraines mark former marginal positions of the retreating ice. A
discontinupus recessional moraine crosses Sussex County from Ogdensburg to Culvers Lake,
about 32 km north of the terminal moraine, and continues up Kittatinny Mountain, where it joins
another moraine. Other small recessional moraines are found in Sussex County (Witte, 1991) and
discontinuous moraines are also found in northern Morris and Passaic Counties (Stanford and
others, 1990). Drumlins are streamlined, elongate hills of till that have their long axes oriented
parallel to the direction of glacial movement: Drumlins are found principally in northern Bergen
County (Salisbury, 1902), near Culvers Lake in Kittatinny Valley, and on Kittatinny Mountain
north of Culvers gap (Stanford and others, 1990). .
IV-11 - Reprinted from USGS Open-File Report 93-292-B
-------
5 10
Figure 5. Map of northern New Jersey showing Pleistocene glacial deposits (modified from B D
Mone, written communication, 1992, and information in Stone and others, 1989). ' '
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GENERALIZED MAP OF GLACIAL DEPOSITS IN NEW JERSEY
EXPLANATION
Glaciofluvial deposits^-coarse-grained, sorted and stratified sand and gravel in
outwash, glaciolacustrine deltas and fans, and eskers
Glacial lake bottom deposits—-stratified and sorted fine-grained sand, silt, and clay
Wisconsinan till—non-stratified, poorly sorted mixture of sand, silt, clay, and
some gravel
, ) •' \
| I | niinoian till—non-stratified, poorly sorted mixture of sand, silt, clay, and ,
some gravel
j •
[*x"x| Pre-niinoian till—deeply weathered, non-stratified, poorly sorted mixture of
sand, silt, clay, and some gravel .
———Limit of Late Wisconsinan glacial deposits ' '.•.•;.
— Limit of niinoian glacial deposits . • -..,•'•
—x — Maximum extent of Pleistocene glacial deposits, excluding glacial and postglacial
meltwater deposits that form coarse-grained terrace deposits in- valleys south of the
glaciated area , •
-------
Glaciofluvial deposits are stratified coarse-grained sand and gravel deposited by glacial
meltwater streams. Outwash plains, flat plains of coarse sand and gravel, occur near Plainfield and
in several valleys south of the terminal moraine. Deposits of other glaciofluvial features such as
eskers and kames, generally referred to as ice-contact stratified deposits, occur locally in northern
New Jersey (Stone and others, 1989).
Glaciolacustrine (glacial lake) deposits consist of stratified, fine-grained sand, silt, and clay
deposited on the bottoms of glacial lakes that were dammed by outwash, moraines, or stagnant ice.
One of the largest glacial lakes was Lake Passaic, which occupied the upper Passaic valley between
the New Jersey Highlands and the Second Watchung Mountain. At its maximum extent, glacial
Lake Passaic was about 30 km long, 13-16 km wide, and 50-60 m deep, with a maximum depth of
about 73 m (Salisbury and Kummel, 1895). Other glacial lakes include Lake Hackensack, which
occupied an area east of the Watchung Mountains, north of Staten Island, and west of the
Palisades, and now comprises the Hackensack Meadowlands; and many smaller lakes that
occupied valleys obstructed by glacial drift, outwash, or stagnant ice, many of which still exist as
modern lakes in the lower parts of glacial lake basins or in large kettles. Deposits of features
related to glacial lakes, such as coarse-grained lacustrine deltas, fans, or wave-cut outwash
terraces, are mapped with glaciofluvial features on figure 5. Glaciolacustrine delta and fan deposits
are stratified silt, sand, and gravel that were deposited where a glacial meltwater river entered a
glacial lake.
SOILS
Soils of six orders—Ultisols, Ihceptisols, Alflsols, Entisols, Spqdosols, and Histosols—:
represent most of the soils in New Jersey (Tedrow, 1986). Ultisols are soils with a horizon
containing an appreciable amount of translocated clay and they often have a moist or wet
substratum. Inceptisols are described as soils with weakly developed horizons in which materials
have been altered or removed and may contain horizons of accumulated silica, iron, or bases, but
they generally do not have clayey subsurface horizons. Alflsols are mineral soils with argillic
(clayey) subsurface horizons or fragipans, and may contain plinthic (iron-rich) or calcic horizons in
the subsurface. Entisols are mineral soils with no discernible pedogenic horizons because their
parent material is inert (such as quartz sand) or because the soils are very young. Spodosols are
mineral soils containing spodic horizons, subsurface accumulations of organic matter and
compounds of aluminum and iron. Spodosols may also have argillic horizons or fragipans beneath
the spodic horizon. Histosols are organic soils such as peats or mucks which occur along
coastlines or in river valleys (Soil Survey Staff, 1975). Figure 6 is a generalized map showing soil
regions of New Jersey. The reader is urged to consult U.S. Soil Conservation Service county soil
surveys or county engineering soil reports published by Rutgers University for more detailed maps
and descriptions of soils for specific areas within the State. • ,
The following discussion is condensed mostly from Tedrow (1961,1986). Soils of the
Valley and Ridge, northern New Jersey Highlands, and northern Piedmont provinces are derived
primarily from glacial deposits, but some of the descriptions given in Tedrow (1961,1986) are
based on the characteristics of bedrock and thus do not necessarily reflect the character of the
surficial deposits in much of northern New Jersey. General descriptions of the characteristics of
glacially-derived surficial deposits are given in the previous section; for more detailed soil
information, the reader should consult the previously-mentioned information sources.
IV-14 Reprinted from USGS Open-File Report 93-292-B
-------
VALLEY
& RIDGE
HIGHLANDS
N
Figure 6. Generalized soil map of New Jersey (modified from Tedrow, 1986).
-------
GENERALIZED SOIL MAP OF NEW JERSEY
EXPLANATION
SOILS OF THE VALLEY AND RIDGE—soils formed on glacial till and sedimentary rocks
1. silt loams with moderate permeability
2. stony sandy loams and loams with firm, compact substrata; moderate permeability
3. clayey and sifty loams with moderate to high permeability
4. clays and clay loams, locally gravelly; low to moderate permeability
V-
*o. 0
SOILS OF THE NEW JERSEY HIGHLANDS—soils developed on glacial till and crystalline rocks
5. stony, loamy soils, some with firm substrata; low Jo moderate permeability
6. organic-rich muck; moderate to high permeability, wet
£J 7. gravelly silt loams with moderate to high permeability, locally low permeability
8. sift loams with moderate permeability '
SOILS OF THE PIEDMONT—soils formed on till, glacial lake sediments, and outwash
9. silty, sandy, and gravelly loams with moderate to high permeability
10. stony silt loams with low to moderate permeability
11. clayey and silty loams with low to moderate permeability
12. sandy and gravelly soils with moderate to high permeability
13. loams with low to moderate permeability >
14. silt loams with hard, compact.substrata; moderate permeability
15. stony silt loams with moderate permeability
16. loams and silt loams with moderate permeability
17. wet, compact, silt loams with low to moderate permeability
SOILS OF THE COASTAL .PLAIN—soils developed on sedimentary rocks and loose sediments
18. sands and clayey sands with moderate to locally low permeability
19. sand with moderate to high permeability
20. sand with moderate to high permeability
21. sandy, sifty, and clayey loams with moderate to high permeability, clayey soils have low perm.
22. sands and silts with clayey substrata; moderate permeability '
23. fine sandy and silty soils with somewhat compact substrata; low to moderate permeability
24. medium sands with small quantities of silt and clay; moderate to high permeability
25. sand with moderate to high permeability
26. wet, sandy soils with a thick organic surface layer; moderate permeability
27. sandy loams with moderate to high permeability
28. wet, organic soils of tidal marshes with low to moderate permeability
-------
Soils of the Valley and Ridge Province include silly, sandy, and gravelly soils. Most of the
soils in the Valley and Ridge are developed on glacial till? outwash, and alluvium Bedrock
outcrops occur on ridgetops and in some valleys in the Valley and Ridge. Unit 1 (fig. 6) consists
of deep well-drained, loose, triable, silt loam soils formed on glacial drift denved from sandstone
and limestone. Unit 2 consists of deep, well-drained, stony sandy loams and loams denved
primarily from sandy glacial till. The soils have a loose surface layer and a firm, compact -
substratum. Unit 3 consists of shallow to deep, well-drained, clayey and silty loams developed on
glacial till derived mainly from shale, limestone, and slate. Unit 4 consists of deep, well-drained,
clayey and loamy soils developed on limestone- and dolostone-derived glacial till. • • •
Soils of the New Jersey Highlands consist mostly of loose, friable, sandy and loamy soils
developed on glacial till deriyed from crystalline rocks. SoilunitS (fig. 6) consists of deep, well-
drained loose, friable, stony, loamy soils developed on glacial till derived from crystalline rocks.
Some soils in this map unit have a firm, but not clay-rich, substratum. Bedrock outcrops occur on
' ridgetops and in some valleys in this soil area. Unit 6 is organic^rich muck that accumulates in
poorly drained, low-lying areas. Muck occurs in many areas of New Jersey that are too small to
be shown on figure 6. Soilsof unit? are deep,well-drained, gravelly silt loams formed on
extensively weathered pre-Wisconsinan glacial drift derived from crystalline rocks. Unit 8 consists
of deep, well-drained, siltloam soils with well-developed clayey B horizons formed in weathered
glacial deposits derived largely from limestone: , ^ i^n^
Soils of the Piedmont are clayey, silty, sandy, and gravelly soils formed on till, glacial lake
sediments, and outwash. Unit 9 consists of deep, well-drained, sandyand gravelly loams • _
developed on glacial till containing red shale as a major source component, and poorly drained silty
and clayey soils developed on glaciolacustrine deposits. Peat soils occur locally. Unit 10 consists
of relatively shallow, well-drained, acidic, stony, silt loams developed on glacial till and volcanic
bedrock Thisurdtismostlycorifmedtoti:aprockridgessuchastheWatchungMountains,Snake
Mountain, and the Palisades. Soils of unit 11 are deep, poorly drained, clayey and siltyloams,
developed on glacial lake sediments. Most of these soils are slowly permeable, wet, and subject to
flooding. Unit 12 soils are deep, well-drained, sandy and gravelly soils developed on glacial
outwash. These soils are generally highly permeable but Ihey have locally high water tables. Soils
of unit 13 are deep, well-drained, loamy soils formed on weathered'pre-Wisconsman glacial drift
derived largely from red shale and some crystalline rocks. The soils may be firm, especially when
dry Unit 14 consists of shallow, well-drained, silty loams formed on red shale. The subsoil may
be hard and compact, especially when dry. Shale fragments are common. Some soils m this map ,
area are silty loams derived from windblown silts. Soil-unit 15 consists of deep, well-drained,
moderately acid, stony silt loams on traprock ridges. These soUs have strongly developed iron-
rich horizons in the subsurface. Unit 16 consists of deep, mdderately acid, well-drained loams and
silt loams formed on deeply weathered gray sandstone. Soils of unit 17 are wet, compact, silt
loams formed on argfflite. These soils have low permeability and poor drainage.
The Coastal Plain is covered by sandy, silty, and clayey soils developed on sedimentary
rocks and unconsolidated sediments. Soil unit 18 consists of deep, poorly- to weU-drained, loose,
sandy soils. SmalTareas within this map unit are composed of poorly drained and well-drained
clayey sands. Unit 19 consists of well-drained, highly permeable, very sandy soils that commonly
have a thin bleached layer at the surface. Soils of unit 20 are deep, well-drained, acidic sands with
a water table that is typically within 0:75 m of the surface. Most of the area is flat-lying and less
than 6 m above tidewater (Tedrow, 1961). Unit 21 soils occur in a complex pattern in Middlesex
and Monmouth Counties. Soils of this unit are sandy and well-drained in higher areas, whereas
. IV-17 Reprinted from USGS Open-File Report 93-292-B
-------
those In lower areas, are poorly drained and high in silt and clay. Soils of unit 22 are well-drained,
acid, loose sands and silts with a hard, reddish, sandy clay texture below 0.75 m that imparts a
low permeability to the soil. Li low-lying areas these soils tend to be wet. Unit 23 consists of
well-drained, fine sandy and silty soils confined to low terraces along the Delaware River. They
are loose and friable at the surface, but somewhat compact at depth. Soils of this unit that are less
than about 2 meters above river level tend to be wet. Unit 24 soils are deep, well-drained, medium
sands with small quantities of silt and clay formed on Coastal Plain deposits containing glauconite.
Unit 25 consists of deep, acid, sandy soils with little silt and clay formed on dry sands. Soils of
unit 26 are poorly drained, wet, sandy soils formed in sandy depressions and along water courses
in the pine region and cedar swamps of New Jersey. The soils commonly have a thick organic
layer at the surface, with brown sand occurring at a depth of 0.75-1.5 m. Unit 27 consists of soils
formed on red sands of the Coastal Plain. They are deep, well-drained, sandy loams with little
profile development Soil unit 28 consists of wet, organic soils of tidal marshes in the coastal
areas of the State. The thickness of these saline marsh peats and mucks commonly exceeds 8 m.
Coastal beach sands, which occur directly adjacent to the shoreline, are included in this unit
RADIOACTIVITY
An aeroradiometric map of New Jersey compiled from National Uranium Resource
Evaluation program (NURE) fiighdine data (Duval and others, 1989) is given in figure 7. Low
radioactivity (<1.5 ppm eU) is associated with the Tertiary and Quaternary sediments of the Outer
Coastal Plain and some of the Silurian and Devonian sedimentary rocks of the Valley and Ridge.
Moderate radioactivity (1.5-2.5 ppm) covers much of the Inner Coastal Plain and the Jurassic
sedimentary rocks of the Piedmont High radioactivity (> 2.5 ppm) is associated with Cambrian
and Ordovician sedimentary rocks of the Valley and Ridge, gneisses of the New Jersey Highlands,
and Triassic sedimentary rocks of the southern Piedmont Muessig (1989) and Muessig and Bell
(1988) give an excellent review of the NURE radiometric anomalies, the geology associated with
them, and the correlation with indoor radon. The individual anomaly map they have derived from
the NURE data is shown in figure 8. The authors have concluded that geology and NURE
radiometric data correlate well with indoor radon. South of the glacial limit, bedrock geology has a
strong influence over the pattern of the NURE aerial radiometric data. North of the glacial limit
the glacial deposits, their morphology, and their source rock appear to be the principal geologic .
controls on NURE anomalies. Bedrock geology is locally important in areas with thin or no glacial
cover. Muessig and Bell (1988) compared geologic provinces, NURE data, and indoor radon
from the NJDEPE study; their comparison is illustrated in figure 9. The provinces shown in figure
9 include important sub-provinces: the Piedmont has been subdivided into a northern and southern
portion along the limit of glaciation and the Coastal Plain has been subdivided into an Inner and
Outer Coastal Plain along the Vincentown-Kirkwood Formation contact. Provinces with the
highest average indoor radon also had the highest average equivalent uranium. The Valley and
Ridge and the New Jersey Highlands were the two highest provinces.
Cluster areas, those areas within the State in which clusters of homes with very high indoor
radon levels occur, were also examined by Muessig and Bell (1988). Nine areas with anomalously
high indoor radon were ground-truthed by geologic mapping, soil sampling, and ground
radiometric traverses. All the localities were within or immediately adjacent to airborne radiometric
anomalies exceeding 6 ppm equivalent uranium. Muessig and Bell (1988) concluded that high
radioactivity, uranium, radium, and thorium concentrated in some of the faults and breccia zones
IV-18 Reprinted from USGS Open-FUe Report 93-292-B
-------
Figure 7. Aerial radiometric map of New Jersey (after Duval and others, 1989). Contour lines at
1.5 and 2.5 ppm equivalent uranium (elJ). Pixels shaded at 0.5 ppm eU increments; darker
pixels have lower elJ values; white indicates no data. '-,, , .
-------
Valley nnd Ridge
Highlands
Southern Piedmont
Length of anomaly line
Is proportionate to magnitude.
Northern Piedmont
Inner Coastal Plain
Outer Coastal Plain
Figure 8. Map showing locations of NUKE anomalies greater than 2.4 ppm equivalent uranium
(from Muessig and Bell, 1988) ' . ,
-------
Val!
Ridge
7.6
2.5
Highlands
Rn Xs.6
eU ? 2.6
ir
Northern Piedmont
Rn -1.7
eu -2.1
Southern Piedmont
Rn- - 4,9
eU -2.7
Inner Coastal Plai
Rn -2.4
eu -1.8
Outer Coastal Plain
Rn-1.4
«U -1.2
Figure 9 Map of New Jersey showing average NURE equivalent uranium (in ppm) and average
indoor radon level (in pCi/L), by province (After Camp Dresser McKee, 1989, and Muesseg and
Bell, 1988). . : •' . ••;.'. ' •
-------
within limestone are the source of high indoor radon in the Clinton cluster. In the Montgomery,
Ewing, and Princeton clusters, situated over Triassic sediments of the Piedmont province, uranium
in the black shales of the Lockatong Formation and uranium along the contact between the
Lockatong and Stockton Formations are the cause of high indoor radon. Precambrian granitic
gneisses are the source of high indoor radon in the Bethlehem, Hampton, Bernardsville, and
Washington clusters. Muessig and Bell (1988) indicate that uranium-rich hornblende granite and
alaskite are the principal sources of the radon in Bethlehem, Hampton, and Bernardsville. In
Washington, the source of the indoor radon is a 9.5-km-long belt of monazite, a thorium
phosphate mineral that also contains uranium. The Mansfield cluster has complicated geology,
with a fault zone separating two distinctly different geologic areas. Homes in the northern portion
of the cluster have faults and fractures in granite alaskite as the source of the radon, and homes in
the southern part of the area have black, uniformly uraniferous shales of the Ordovician
Martinsburg Formation as the source of the high indoor radon levels.
Uranium occurrences in the State are well documented. Bell (1983) has published a
comprehensive review and map of all the known radioactive mineral occurrences in New Jersey.
The sizes of the occurrences range from single outcrops to mineral belts several kilometers long.
Other sources of information on the radioactivity of rocks in New Jersey include: Grauch and
Zarinsky (1976), Turner-Peterson (1980), Olsen (1988), Gundersen (1986), Volkert (1987),
Muessig (1989), and Muessig and others (1992). Most occurrences of uranium enrichment are
located in the New Jersey Highlands. Uraninite and other U-bearing minerals form layers and
disseminations in several kinds of host rocks in the Highlands, including magnetite deposits,
pegmatites, intrusive granitic rocks, marble, veins, faults, shear zones, and biotite-garnet gneiss
with layers of monazite and xenotime. Uranium mineralization in the gneisses and magnetite
deposits may be conformable with the compositional layering. General rock types with overall
elevated uranium include quartz-potassium feldspar gneiss, biotite-garnet gneiss, and most granite,
especially hornblende-bearing granite (Volkert, 1987; Muessig, 1989; Muessig and others, 1992).
Rock types which tend to be low in uranium include amphibolitic gneisses, most marbles, and
tonalitic, syenitic, and trondjhemitic gneisses. Pegmatites and migmatitic rocks of the Byram
Intrusive Suite may also be elevated in uranium.
In several parts of the New Jersey Highlands and in the Valley and Ridge section,
sedimentary rocks of Cambrian through Devonian age comprise the underlying bedrock.
Cambrian and Qrdovician rocks are a marine shelf sequence with basal Cambrian sandstones and
conglomerates followed by a highly variable sequence of interbedded shales, dolomites, and
limestones. Uranium-bearing minerals are found in the basal conglomerates of the Cambrian
Hardyston Quartzite. Many of the black shales in the Paleozoic section, such as the Ordovician
Martinsburg Formation, are elevated in uranium (Muessig, 1988). Carbonate rocks are usually
low in radionuclide elements, but the soils developed from carbonate rocks are often elevated in
uranium and radium. Carbonate soils are derived from the dissolution of the calcium carbonate
(CaCOs) that makes up the majority of the rock. When the CaCOs has been dissolved away, the
soils are enriched in the remaining impurities, predominantly base metals, including radionuclides
(Schultz and others, 1992). Rinds containing high concentrations of uranium and uranium-
minerals can be formed on the surfaces of rocks involved with CaCOs dissolution and
karstification. Karst and cave morphology is also thought to promote the flow and accumulation of
radon. Some of the Cambrian-Ordovician dolomites of New Jersey have been faulted and
hydrothermal deposition of uranium has occurred locally, as in the Clinton cluster of high indoor
radon (McKeown and Klemic, 1953; Popper andBlauvelt, 1980; Muessig, 1989; Muessig and
IV-22 Reprinted from USGS Open-File Report 93-292-B
-------
Bell, 1988; Henry and others, 1991). Two belts of Silurian and Devonian sedimentary rocks are
found in the northwesternmost part of the State in the Valley and Ridge, and in the north-central
part of the State within the New Jersey Highlands. ThesS rocks are composed of conglomerate,
sandstone, shale, and minor limestone. The sandstones and conglomerates are generally low, in
uranium or have very local uranium occurrences in some of the conglomerates and channel
sandstones. Some of the marine black shales, such as the Marcellus Formation, have elevated
uranium (LKB Resources, 1978).
., In the Triassic rocks of the Piedmont Province, lacustrine black shales of the Lockatong
Formation are the principal uranium-bearing rocks (Muessig, 1989; Muessig and others, 1992).
Uranium occurrences have also been noted in the upper Stockton Formation in fluvial sandstones
-associated with gray shale lenses (Turner-Peterson, 1980) and in black shales of the Lower Passaic
Formation (Olsen, 1988). There may also be elevated uranium associated with black shales and ,
gray sandstones of the upper Passaic, Feltville, Towaco, and Boonton Formations (Smoot, J.P.,
pers. comm., 1992). Thermally-altered Paleozoic limestone or conglomerates consisting of
limestone clasts near diabase bodies, as in the area northeast of the Delaware River along the
border fault of the basin, may also have elevated uranium concentrations (Robinson, 1988).
In 1988, the U.S. Geological Survey and the U.S. Environmental Protection Agency
initiated a program to assess the radon potential of the Coastal Plain sediments in the United States
(Gundersen and others, 1991). In New Jersey, radon in soil gas, surface gamma-ray activity, and
permeability were measured, and core and auger samples of soils and sediment were examined.
The highest soil-gas radon concentrations and equivalent uranium (eU) concentrations (measured
by portable gamma-ray spectrometer) were found in the glauconitic sands of the Cretaceous
Englishtown and Navesink Formations, the Mount Laurel Sand, and the Tertiary Hornerstown
Sand. In these units, soil radon exceeded 3000 pCi/L and average eU was greater than 2.5 ppm.
Units that had the lowest soil radon concentrations and eU include the Cretaceous Red Bank Sand
and Magothy Formation, the Tertiary Kirkwood Formation and Cohansey Sand, and Pleistocene
residuum. Soil-gas radon concentrations in these units were generally less than 10QO pCi/L and
eU was generally less than 1 ppm. Low to moderate soil radon and eU ppm concentrations were
measured in the Cretaceous Wenonah and Tertiary Bridgetpn Formations, the Cretaceous
Woodbury Clay, and the Tertiary Vincentown Formation.
INDOORRADON
m 1986, the New Jersey Department of the Environmental Protection and Energy
(NJDEPE) initiated the Statewide Scientific Study of Radon. The study was conducted by the
NJDEPE, Radiation Protection Element, Bureau of Environmental Radiation, with the assistance
of Camp Dresser and McKee, Inc. (CDM). In this comprehensive statistical study, more than
6000 homes and other buildings were randomly sampled for indoor radon using charcoal canisters,
and an extensive database of geologic, soil, political, demographic, meteorological, building
features, and resident behavior was collected and compared with the indoor radon data. Follow-up
detailed sampling was conducted in 200 homes and ground-water sampling was conducted at 300
homes. The State was divided into six geologic provinces (fig, 9) to help organize the sampling
and analyses and compare the data on a geologic basis. The highest average indoor radon was
found in the New Jersey Highlands and the Valley and Ridge Province. More than half of the
indoor radon measurements in these provinces exceeded 4 pCi/L. The Southern Piedmont also had
an average exceeding 4 pCi/L. In every province of the State, at least 5: percent of the readings
IV-23 Reprinted from USGS Open-File Report 93-292-B
-------
were 4 pCi/L or more, and at least one home in every province had more than 30 pCi/L. Within
each province, variability in measurements was high. Figure 10, taken from the COM report,
illustrates the distribution of indoor radon within several different ranges of values.
Since the completion of the CDM work, the NJDEPE has compiled additional indoor radon
data and now has a database of more than 150,000 measurements (Table 1). These data were
supplied to the NJDEPE by commercial vendors and are predominantly lowest living area
screening measurements made by charcoal canister, although some alpha-track and e-perm
measurements are included. Figure 11 shows the NJDEPE indoor radon data by county, and
figure 12 is a map of counties and their names for reference. Homes with indoor radon levels
greater than 4 pCi/L are most prevalent in the Valley and Ridge, the New Jersey Highlands, and
Southern Piedmont Homes with indoor radon levels greater than 20 pCi/L are restricted to parts
of the Valley and Ridge, the Southern Piedmont, the New Jersey Highlands, and certain rock units
of the Inner Coastal Plain. ,,
GEOLOGIC RADON POTENTIAL
A radon potential map was produced by CDM (Camp Dresser and McKee, 1989) from the
extensive data collected during the NJDEPE Statewide Scientific Study of Radon. The map is
reproduced here as figure 13. Low radon potential has been assigned to the upper Tertiary and
Quaternary sediments of the Outer Coastal Plain, the Silurian and Devonian rocks of the Valley and
Ridge, and some of the Triassic and Jurassic sedimentary and igneous rocks of the northern and
southern Piedmont High radon potential has been assigned to most of the New Jersey Highlands,
the eastern and central portions of the Valley and Ridge Province, and the Triassic sedimentary
rocks of the Southern Piedmont and parts of the Northern Piedmont Moderate radon potential has.
been assigned to the sediments of the Inner Coastal Plain, some of the Triassic and Jurassic rocks
of the Piedmont, some of the Ordovician sedimentary rocks of the Valley and Ridge, and
Cambrian-Devonian rocks in the New Jersey Highlands, The NJDEPE has also classified all
municipalities of the State as having high, moderate, or low potential for elevated radon based on
the data given in Table 1, and this map is reproduced in figure 14.
As part of an Interagency Agreement between the EPA and the USGS, the USGS has
prepared geologic radon potential estimates of the land for each state in the United States. In a few
states, such as New Jersey, comprehensive radon potential programs have been active since the
recognition of indoor radon as a health problem. In the preceding sections, we have presented the
results of the NJDEPE Statewide Scientific Study of Radon, which utilized a wide variety of
important geologic and cultural data to examine the status of radon problems and health risk in the
State, and target future study areas. The following section presents a geologic radon potential •
assessment of the land in New Jersey, concentrating on the geologic factors and using a semi-
quantitative numeric index to rank areas by geologic province. The assessment uses similar data
to, and has been greatly augmented by, the NJDEPE study. The results of the USGS assessment
are similar to those obtained by CDM, with few differences. The USGS assessment examines
only the geologic radon potential of the land and not health risk or exposure. The assessment done
by the USGS is presented in Table 2 and discussed in the following section. The USGS has used
the same basic subdivisions as Muessig and Bell (1988) and Camp Dresser and McKee, Inc.
(1989), and also have separately delineated the Silurian and Devonian-age rocks of the Green Pond
outlier and the western Valley and Ridge.
IV-24 Reprinted from USGS Open-File Report 93-292-B
-------
Jo
•p't
,:5 c
ON
oo
ON
8.
S
J-«£
5 e
.•s p
5
«! _
l!
e =•
c
2 «
e w
c o
U
S
en
2
V
•en
•' C
i-i'
•'8
o
3
s-
00'
I
-------
TABLE 1. Screening indoor radon data for New Jersey compiled by the New Jersey Department
of Environmental Protection and Energy. Data are compiled from vendor reports collected by
NJDEP from 1986 through 1992 and represent primarily 2-7 day charcoal canister measurements,
although some alpha-track and e-perm detector data are also included.
COUNTY
Atlantic
Bergen
Burlington
Camden
Cape May
Cumberland
Essex
Gloucester
Hudson
Hunterdon
Mercer
Middlesex
Monmouth
Morris
Ocean
Passaic
Salem
Somerset
Sussex
Union
Warren
STATEWIDE
NO. OF
MEAS.
225
14887
3631
4029
55
287
10598
1229
1390
9465
11535
12325
11176
27624
997
6031
215
16382
6536
7855
4981
151,453
ARITHMbTiC
MEAN
1.3
1.8
2.2
2.6
1.1
3.5
1.9
3.0
1.5
9.4
6.1
2.8
4.0,
4.5
1.5
2.6
2.6
5,1
6.5
2.2
9.5
4.3
%>4 pCi/L
4
8
12
" 15
4
• 16
8
. 19
5
47
30
19
26
28
4,
17
18
35
41
11
54
25
-------
Bsmt.& 1st Floor Rn
OtolO
8 K\\\\\» 11 to 20
4 ESSS3 21 to 40
3 41 to 60
Bsmt.& 1st Floor Rn
Average Concentration (pCi/L)
6
* " *' 0.0to1.9
2.0 to 4.0
6 K-N?K^a 4.1 to 9-5
100 Miles
Figure 11. Screening indoor radon data compiled by the New Jersey Department of Environmental
Protection and Energy from vendor reports collected by NJDEP from 1986 through 1992. Data
represent primarily 2-7 day charcoal canister measurements, although some alpha-track and e-peim
detector data are also included. Histograms in map legend show the number of counties in each
category. ' .
-------
w-
10 20
30
Figure 12. New Jersey counties (from Facts on File, 1984).
-------
JTTD Low Radon Potential
Medium Radon Potential
High Radon Potential
Radon Screening Level
over 20 pCi/1
Figure 13. Map showing radon potential areas of New Jersey identified by the New Jersey DEP
(from Camp Dresser McKee, 1989).
-------
TIER 1 - HIGH RADON POTENTIAL •
TIER 2 - MODERATE RADON POTENTIAL
TIER 3 - LOW RADON POTENTIAL
Figure 14. Radon potential tier map for New Jersey compiled by the New Jersey Department of
Environmental Protection and Energy. Tiers rankings are based on indoor radon data from more
than^lSO.OOO homes compiled from vendor records and the State's radon testing program. Tier 1
municipalities are those in which 25% or more of the homes have indoor radon levels >4 pCi/L,
Tier 2 municipalities are those in which 5-24% of the homes have indoor radon levels >4 pCi/L,
and municipalities assigned to Tier 3 are those in which 4% or less of the homes have indoor radon
levels >4 pCi/L. Map courtesy of Barbara Plunkett and Herbert Roy, NJDEPE.
-------
For the purpose of this assessment, New Jersey has been divided into eight geologic radon
potential areas and each area assigned a Radon Index (Rwanda Confidence Index (CI) score
(Table 2) using the information outlined in this chapter. Please see the Introduction chapter to this
regional book for a detailed explanation of the Indexes. The RI is a semi-quantitative measure of
radon potential based on geology, soils, radioactivity, architecture, and indoor radon, The CI is a
measure of the relative confidence of the RI assessment based on the quality 'and quantity of the
data used to assess geologic radon potential. , ' '
As can be seen in Table 2, the New Jersey Highlands have been ranked high in geologic
radonpotential. The average screeningmeasurement of indoor radon in this province is expected
to be greater than 4 pCi/L. Screening measurements of indoor radon in the Highlands averaged
86 pO/L in the NJDEPE study. The NURE data for the Highlands indicates many high
equivalent uranium anomalies (>2.5 ppm). Uranium in rocks of the New Jersey Highlands is well-
documented in the literature. Uraninite and other U-bearing minerals form layers and
dissemination's in several kinds of host rocks in the Highlands, including intrusive granitic rocks,
magnetite deposits, pegmatites,.marble, veins, faults, shear zones, and feldspathic
metasedimentary gneiss. Soil permeability is generally moderate to high with a few areas of low
permeability. Glacial deposits in the Highlands are, for the most part, locally derived and, in some
areas, they enhance radon potential because of high permeability. In other areas, glacial deposits
may blanket bedrock and effectively lower the radon potential (Gates and others, 1990).
The Valley and Ridge Province has been divided into two sections for this assessment..
The Silurian and Devonian rocks of the Valley and Ridge and the Green Pond outlier have been
ranked moderate in radon potential. The Silurian and Devonian rocks generally have low to .
moderate equivalent uranium associated with them in the NURE data. They are predominantly
conglomerate, sandstone, shale, and limestone. The shales and local uranium mineral •
accumulations in the sandstones are the most likely source of radon problems. Figure 10 indicates
that only a few homes with indoor radon greater than 20 pCi/Lwere measured in the Silurian and
Devonian rocks. ,,,.,_• 1 •
The Cambrian-Ordovician rocks of the Valley and Ridge have been ranked high in geologic
radonpotential. TheHardyston Quartzite is known.to have local uranium and uranium mineral
deposits and the black shales and carbonate soils are also sources of indoor radon. Screening
measurements of indoor radon in the Valley and Ridge averaged 7.6 pCi/L in the NJDEPE study.
Equivalent uranium from the NURE data is generally moderate to high over the Cambrian and
Ordovician sedimentary rocks. Permeability is generally moderate.
The northern and southern Piedmont provinces together form the Newark Basin. The
basin is underlain by Triassic sandstone, siltstone, and shale, Jurassic basalt and diabase, and
Jurassic siltstone, shale, and sandstone. Of all these rock types, the black shales have the greatest
potential to be a source of radon problems. Black shales are not as abundant in the Northern
Piedmont as in the Southern Piedmont. The average indoor radon from the NJDEPE study for the
Northern Piedmont is 1.7 pCi/L. Indoor radon levels between 4 and 20 pCi/L in the Northern
Piedmont (fig. 10) are probably associated with the black shales of the lower Passaic Formation
and uranium mineralization along the northern border fault and in adjacent rocks. The NURE data
are sparse for the northern Piedmont because the aerial radiometric survey was not flown in.highly
populated urban areas. Sandstones and conglomerates of the upper Passaic Formatipn with low
radon potential dominate the northwestern portion of the Northern Piedmont. Jurassic basalts and
interbedded sandstones and shales with low to moderate radon potential make up the western half
of the Northern Piedmont. Low to moderate radon potential is expected for the eastern half of the
IV-31 Reprinted from USGS Open-File Report 93-292-B
-------
Northern Piedmont, which is underlain by sandstones interbedded with lacustrine shales of the
Passaic Formation and diabase of the Palisades sill that intrudes along the Lockatong Formation-
Stockton Formation contact This thin layer of Lockatong Formation may be responsible for the
single reading over 20 pCi/L found near here. Soil permeability is generally low to moderate in the
Northern Piedmont. The Northern Piedmont Province has been ranked low in geologic radon
'potential overall.
The Southern Piedmont is underlain by the uraniferous black shales and siltstones of the
Lower Passaic Formation, the uraniferous black shales of the Lockatong Formation, and the
uraniferous black shales and locally uraniferous sandstones of the Stockton Formation. Average
indoor radon for the Southern Piedmont is high at 4.9 pCi/L. Equivalent uranium from the NUKE
data is also moderate to high. Soil permeability is low to moderate. The Southern Piedmont has
been ranked high in geologic radon potential.
The Inner Coastal Plain Province, consisting of Cretaceous and Lower Tertiary sediments,
has been ranked moderate in radon potential. Screening measurements of indoor radon in the Inner
Coastal Plain averaged 2.4 pCi/L in the NJDEPE study. Equivalent uranium from the NUKE data
is generally moderate. Soil permeability is moderate to high. Soil radon studies indicate that the
glauconitic sediments are significant sources of radon. The highest soil radon concentrations and
ell concentrations were found in the glauconitic sands of the Cretaceous Eriglishtpwn and
Navesink Formations, the Mount Laurel Sand, and the Tertiary Hornerstown Sand.
The Outer Coastal Plain has been ranked low in geologic radon potential. Soil radon studies
of the Tertiary Kirkwood Formation, Cohansey Sand, and Pleistocene residuum indicate that they
are poor sources of radon. Equivalent uranium from the NURE data is generally low. Soil
permeability is moderate to high and the average indoor radon for the province is low (1.4 pCi/L).:
This is a generalized assessment of the State's geologic radon potential and there is no
substitute for having a home tested. The conclusions about radon potential presented in this report
cannot be applied to individual homes or building sites. Indoor radon levels, both high and low,
can be quite localized, and within any radon potential area there will likely be areas with higher or
lower radon potential that assigned to the area as a whole. Any local decisions about radon should
not be made without consulting all available local data. State law requires that residential and
school structures built in municipalities that the State has classified with a high radon potential use
construction techniques that minimize radon entry and facilitate post-construction removal of
radon. For additional information, contact the New Jersey Radon Program at 800-648-0934 (New
Jersey only) or 609-987-6396. More detailed information on state or local geology may be
obtained from the New Jersey geological survey.
IV-32 Reprinted from USGS Open-File Report 93-292TB
-------
TABLE 2. RI and CIscores for geologic radon potential areas of New Jersey.
FACTOR
INDOOR RADON
RADIOACTIVITY
GEOLOGY
- SOIL PERM.
ARCHITECTURE
GFE POINTS
TOTAL
New Jersey
Highlands
RI CI
3
3
2
2
3
2
15
High
3
- 3
2
2
10
High
Cambrian and Ordovician
Valley and Ridge
RI CI
3
3
3
2
3
0
14
High
3
3
' 2
2
10
High
Southern
Piedmont
RI CI
3
3
3
2
* ' • 3
0
14,
.High
3 •
3
3
' 2
11
High
Silurian and Devonian Northern Piedmont
Valley anfl Ridge/Green Pond Outlier
Inner Coastal Plain
CretaCeous-Lower Tertiary
RI
CI
RI
CI
RI
CI
INDOOR RADON
RADIOACTIVITY
GEOLOGY
SOIL PERM.
ARCHITECTURE
GFE POINTS
TOTAL
' 2 ••
2
. 2
2
3
0
11
Mod
3
3
2
3
" .'.
11
High
1
1
2'
2
2
0 .
8
Low
3
1
2
,2
.
••• - •
8
Mod
2
2
2
2
2 .
0
10
Mod
3
2
3
.3
•-
-. -
11
High
Outer Coastal Plain
Upper Tertiary-Quaternary
FACTOR
INDOOR RADON
RADIOACTIVITY
GEOLOGY
SOIL PERM.
ARCHITECTURE
^ GEE POINTS
TOTAL
RI
1
1
1
3
2
0
8 ,
Low
CI
3
2
3
3
1.1
High
RADON INDEX SCORING:
Radon potential category
LOW - 3-8 points
MODERATE/VARIABLE 9-11 points
HIGH > 11 points
Possible range of points =3 to 17
Probable screening indoor
Point ranee radon average for area
<2pO/L
2-4pCi/L
>4pCi/L
CONFIDENCE INDEX SCORING:
LOW CONFIDENCE
MODERATE CONFIDENCE'
HIGH CONFIDENCE
4-6 points
7-9 points
10 - 12 points
Possible range of points = 4 to 12
IV-33 . Reprinted from USGS Open-File Report 93-292-B
-------
REFERENCES CITED IN THIS REPORT
AND OTHER REFERENCES PERTAINING TO RADON IN NEW JERSEY
Anderson, S.B., 1983, Levels of Ra-226 and Rn-222 in well water of Mercer County, New
Jersey: Bachelor's Thesis, Princeton Univ., Princeton, NJ, USA, 59 p.
Bell, Christy, 1983, Radioactive Mineral Occurrences in New Jersey: New Jersey Geological
survey Open-File report No. 83-5, 21p.
Camp Dresser and McKee, Incorporated, 1989, Summary Report-Statewide Scientific Study of
Radon, New Jersey Department of Environmental Protection, Bureau of Environmental
Radiation, upubl. report. -, -
Cohen, B.L. and Gromicko, N., 1988, University of Pittsburgh measurements in New Jersey
and eastern Pennsylvania, in W. J. Makofske and M.R. Edelstein (eds.), Radon and the
environment: Proceedings of Radon and the environment, Mahwah, NJ, May 8-10,1986,
p. 56-61.
Cohen, B.L., 1988, Dissociation between lung cancer and a geological outcrop-discussion and
reply: Health Physics, v. 54, p. 224-226.
Countess, R.Y., 1978, Measurement of 222Rn in water: Health Physics, v. 34, p. 390.
Drake, A.A., Jr., 1984, The Reading Prong of New Jersey and eastern Pennsylvania: An appraisal
of rock relations and chemistry of a major Proterozoic terrane in the Appalachians, in M.J.
Bartholomew (ed.), The Grenville Event in the Appalachians and Related Topics:
Geological Society of America Special Paper 194, p. 94-109.
Drake, A.A., Jr., 1990, The regional geologic setting of the Franklin-Sterling Hill district, in
Proceedings of Character and Origin of the Franklin-Sterling Hill Orebodies, Lehigh
University, Bethlehem, Pennsylvania, Lehigh University, p. 14-30.
Drake, A.A., Jr., Aleinikoff, J.N., and Volkert, R.A., 1990, Syn- and post-kinematic granites of
the New Jersey Highlands: Geological Society of America, Abstracts with Programs,
v. 22, no. 2, p. 12.
Drake, A.A., Jr., Aleinikoff, J.N., and Volkert, R.A., 1991, The Byram Intrusive Suite of the
Reading Prong: Age and tectonic environment: in Drake, A. A., Jr. (ed.), Contributions to
New Jersey Geology: U.S. Geological Survey Bulletin 1952, P. Dl-D-14.
Drake, A.A., Jr., and Volkert, R.A., 1991, The Lake Hopatacong intrusive Suite (Middle
Proterozoic) of the New Jersey Highlands: in Drake, A.A., Jr. (ed.), Contributions to New
Jersey Geology: U.S. Geological Survey Bulletin 1952, P. A-l-A-9. '
Dombrowski, D.R., Jr., 1990, Index of New Jersey geologic maps: New Jersey Geological
Survey Report GSR 24,32 p.
IV-34 Reprinted from USGS Open-File Report 93-292-B
-------
Duval, J.S., 1987, Identification of areas with pptentiaKor indoor radon hazard using gamma-ray
'measurements ofsurface uranium, potassium, andthorium concentrations: Geological
Societyof America, Abstracts with Programs, v. 19, p. 82. - . .
Duval, J.S., Jones, W.J., Riggle, F.R., and Pitkin, J.A., 1989, Equivalent uranium map of
conterminous United States: U.S. Geological Survey Open-File Report 89-478,10 p.
Facts on File Inc., 1984, State Maps on File. ;
Fakundiny, R.H., and Friedman, G.M., 1988 .Workshop on geology and radon: Northeastern
Environmental Science, v. 7, p. 63-69.
• • , i "'"'',.
Fleischer, R.L., 1986, A possible association between lung cancer and a geological outcrop:
Health Physics, v. 50, p. 823-827. \ . ,
Fullerton, D.S., 1986, Stratigraphy and correlation of glacial deposits from Indiana to New York
and New Jersey, m Sibrava, V., Bowen, D.Q., and Richmond, G.M. (eds.), Quaternary
glaciations in the Northern Hemisphere: Quaternary Science Reviews, v. 5, p. 23-36.
Gates, A.E., Gundersen, L.C.S., and Malizzi, L.D., 1990, Comparison of radioactive element
distribution between similar faulted crystalline terranes: Glaciated versus unglaciated:
Geophysical Research Letters, v. 17, p. 813-816.
George, A.C., and Eng, J., 1983, Indoor radon measurements in New Jersey, New York, and
Pennsylvania: Health Physics, v. 45, p. 397-400.
Grauch, R.I., and Zarinski, K., 1976, Generalized descriptions of uranium-bearing veins,
pegmatites, and disseminations in non-sedimentary rocks, eastern United States: U.S.
Geological Survey Open-File Report 76-582. ,
Gundersen, L.C., 1986, Geology and geochemistry of the Precambrian rocks of the Reading
Prong, New York and New Jersey: Implications for the genesis of iron-uranium and rare-
earth element deposits, in L.M.H. Carter (ed.), Proceedings of Second Annual V.E. _
McKelvey Forum on Mineral and Energy Resources,.Denver, Colorado,, U.S. Geological
Survey Circular 974, p. 19.
Gundersen, L. C.S, Peake, R.T., Latske, G.D., Hauser, L.M., and Wiggs,C.R., 1991, A
statistical summary of uranium and radon in soils from the Coastal Plain of Texas,
Alabama, and New Jersey, in Proceedings of the 1990 International Symposium on Radon
and Radon Reduction Technology,Vplume 2: Symposium Oral Papers,
EPA-600/9-91/026b, p.CVI4-1-13.
Gundersen, L.C.S., 1991, Radon in sheared metamorphic and igneous rocks: in Gundersen,
L.C.S., and Wanty, R.B. (eds.), Field Studies of Radon in Rocks, Soils, and Water;
U.S. Geological Survey Bulletin 1971, p. 38-49.
IV-35 Repiinted from USGS Open-File Report 93-292-B
-------
Gundersen, L.C.S.,JReimer, G.M., and Agard, S.S., 1988, Correlation between geology, radon
in soil gas, and indoor radon in the Reading Prong, in M.A. Marikos and R.H. Hansman
(eds.), Geologic causes of natural radionuclide anomalies: Proceedings of the GEORAD
conference St. Louis, MO, April 21-22,1987, Missouri Department of Natural Resources
Special Publication 4, p. 91-102.
Harley, N.H., and Chittaporn, P., 1989, Sources of indoor radon; subfloor soil gas variability:
Health Physics, v. 56, p. 70.
Harper, 1991 (ed.) Geologic Research in New Jersey, 1991: New Jersey Geological Survey
Open-File Report OFR 91-2.
Herman, G.C., and Mitchell, J.P., 1989, Geology of the Green Pond outlier from Dover to
Greenwood Lake, New Jersey: NJ. Geological Survey open File Report.
Henry, M.li., Kaeding, M., and Monteverde, D., 1989, Radon in soil gas and gamma ray activity
measurements at Mulligan's Quarry, Clinton, New Jersey: Geological Society of America
Abstracts with Programs, v. 21, no. 2, p. 22.
Henry, M.E., Kaeding, M., and Monteverde, D., 1991, Radon in soil gas and gamma ray
activity measurements at Mulligan's Quarry, Clinton, New Jersey^ in Gundersen, L.C.S.,
and Wanty, R.B. (eds.), Field Studies of Radon in Rocks, Soils, and Water; U.S.
Geological Survey Bulletin 1971, p. 65-76.
Hotte, E.D., 1987 , New Jersey's approach to a radon cluster; Clinton: Geological Society of
America, Abstracts with Programs, v. 19, p. 90.
Kroll, R.L., and Brown, J.O. (eds.), 1990, Field Guide and Proceedings, Seventh Annual
Meeting of the Geological Association of New Jersey, collected papers and field guides.
Lapoti, Jill A., 1991, New Jersey radon program, 1991, in The 1991 International Symposium on
Radon and Radon Reduction Technology, Proceedings, Volume 2, Symposium Oral
Papers, Technical Sessions 6 through 10: U.S. Environmental Protection Agency Rept.
EPA/600/9-91/037B, p. 7-38-7-44.
Litt, B.R., Bell, C., and Moser, F.C., 1989 , Investigation of radon-222 in ground water supplies
in the Reading Prong, New Jersey: Health Physics, v. 56, p. 52.
LKB Resources, Inc., 1978, NURE aerial gamma-ray and magnetic reconnaissance survey,
Scranton quadrangle: U.S. Department of Energy NURE Report GJBX-32 (78), 126 p.
McKeown, F.A., and Klemic, H, 1953, Reconnaissance for radioactive minerals in the
northeastern United States during 1952: U.S. Geological Survey Trace Element
Investigations 317-A, 68 p.
IV-36 Reprinted from USGS Open-File Report 93-292-B
-------
Minard, J.P., and Rhodehamel,' E.G., 1969, Quaternary geology of part of northern New Jersey
and the Trenton area, in Subitzky, S. (ed.), Geology of selected areas in New Jersey and
Pennsylvania and guidebook of excursions: New Brunswick, New Jersey,"Rutgers
University Press, prepared for the Geological Society of America, p. 279-313.
Muessig, K., and Bell, C., 1988, Use of airborne radiometric data to direct testing for elevated
indoor radon: Northeastern Environmental Science, v. 7, p. 45-51.
Muessig, K.W., 1989, Uranium cycling in the crust and its relationship to radon hazards in New
Jersey: Geological Society of America, Abstracts with Programs, v. 21, no. 2, p. 53.
Muessig, K., Houghton, H., Monteverde, D., and Volkert, R., 1992, A geologic transect through
the uraniferous provinces of New Jersey and their associated radon hazards: New Jersey
geological Survey Open File 92-2,29 p.
Neiheisel, J., and Battist, L., 1987, Contributory role of Mesozoic tectonic events to radon
sources in the Appalachian region: Geological Society of America, Abstracts with
Programs, v. 19, p. 120. ,
New Jersey Geological Survey, 1984, Geologic map of New Jersey, scale 1:1,000,000.
Nicholls, G.P., and Deieso, D.A., 1987, New Jersey; involving the commercial, sector:
Environment, v. 29, p. 12, 14, 34-37. l> . •
Nicholls, G.P., 1989, The distribution of indoor radon in new Jersey: New Jersey Academy of
Science Bulletin, v. 34, p. 9-16.
Olsen, P.E., 1988, Continuity of strata in the Newark and Hartford basins, in Froelich, A.J., and
Robinson, G.R. Jr, (eds.), Studies of the Early Mesozoic Basins of the Eastern United
States: U.S. Geological Survey Bulletin 1776, p: 6-18.
Popper, G.H.P., and Blauvelt, R.P., 1980, Work plan, Newark Quadrangle, covering parts of
Pennsylvania and New. Jersey: Bendix Field Engineering Corporation, 45 p.
Powell, J.A., and Schutz, D.F., 1987, Pre-construction site qualification for susceptibility to
radon emanation: Geological Society of America, Abstracts with Programs, v. 19, p. 124.
,••*-. .,'•.-.• ' • .. •
Puffer, J.H., and Volkert, R.A-, 1990, Geochemistry of middle Proterozoic tonalite/trondhjemite
suite from the New Jersey Highlands: Geological Society of America, Abstracts with
Programs, v. 22, no. 2, p. 63. ,"
Richmond, G.M., and Fullerton, D.S. (compilers), 1992, Quaternary geologic map of the Hudson
River 4°x6° quadrangle; United States and Canada: U.S. Geological Survey Miscellaneous
Investigations Map 1-1420 (NK-18), scale 1:1,000,000. ,
IV-37 Reprinted from USGS Open-File Report 93-292-B
-------
Robinson, G.R., Jr., 1988, Base and precious metals associated with diabase in the Newark,
Gettysburg, and Culpeper basins of the eastern United States-A review: in Froelich, A.J.,
and Robinson, G.R. (eds.), Studies of the Early Mesozoic basins of the eastern United
States, U.S. Geological Survey Bulletin 1776, p. 303-320.
Salisbury, R.D., 1902, The glacial geology of New Jersey: New Jersey Geological Survey Final
Report, v. 5, 802 p.
Salisbury, R.D., and Kummel, H.B., 1895, Lake Passaic, an extinct glacial lake: Journal of
Geology, v. 3, p. 533-560.
Schultz, A.P., Wiggs, C.R., and Brower, S.D., 1992, Geologic and environmental implications
of high soil-gas radon concentrations in the Great Valley, Jefferson and Berkeley Counties,
West Virginia, in Gates, A.E., and Gundersen, L.C.S. (eds), Geologic controls on radon:
Geological Society of America Special Paper 271, p. 29-44.
Schutz, D.F., and Powell, J.A., 1988, The influence of geologic environment on the distribution
of uranium/radon in New Jersey, in W. J. Makofske and M.R. Edelstein (eds.), Radon and
the environment: Proceedings of Radon and the Environment, Mahwah, NJ, May 8-10,
1986, p. 35-47.
Sextro, R.G., and Turk, B.H., 1989, Variability in soil radon concentrations and air
permeabilities: Eos, Transactions, American Geophysical Union, v. 70, p. 721.
Shafer, P.H., 1983, Distribution of radon-222 and radium-226 in the Carnegie Lake system,
Princeton, New Jersey: unpublished Bachelor's Thesis, Princeton Univ., Princeton, NJ,
55p.
Smoot, J.P., 1991, Sedimentary facies and depositional environments of early Mesozoic Newark
Supergroup basins, eastern North America: Paleogeography, Paleoclimatology,
Paleoecology, v. 84, p. 394-423.
Soil Survey Staff, 1975, Soil taxonomy: U.S. Department of Agriculture, Soil Conservation
Service Agriculture Handbook 436,754 p.
Stanford, S.D., Witte, R.W., and Harper, D.P., 1990, Hydrologic character and thickness of the
glacial sediment of New Jersey: New Jersey Geological Survey Open-File Map 3, scale
1:000^000.
Stone, B.D., Stanford, S.D., and Witte, R.W., 1989, Preliminary surficial geologic map of
northern New Jersey: Geological Society of America, Abstracts with Programs, v. 21,
no. 2, p. 69.
Subitzky, Seymour, (ed.), 1969, Geology of selected areas in New Jersey and eastern
Pennsylvania and guidebook of excursions: Rutgers University Press, 382 p.
IV-38 Reprinted from USGS Open-File Report 93-292TB
-------
Szabo, Z., and Sapecza, O.S., 1987, Relation between natural radionuclide activities and
' chemical constituents in ground water of the Newark Basin, New Jersey, in B. Graves
(ed.), Radon, radium, and other radioactivity in ground water: Lewis Publishers,
p, 283-308. :
Szabo, Z., and Zapecza, O.S., 1991, Geologic and geochemical factors controlling uranium,
radium-226, arid radon-222 in ground water, Newark basin, New Jersey: in Gundersen,
L.C.S., and Wanty R.B. (eds.), Field Studies of Radon in Rocks, Soils, and Water; U.S.
Geological Survey Bulletin 1971, p. 243-265.
Tedrow, J.C.F., 1961, New Jersey soils: New Jersey Agricultural Experiment Station Circular
•,6pi,2o p. ".:'
' • , > , •"
Tedrow, J.C.F., 1986, Soils of New Jersey: Malabar, Ha., Robert E. Krieger Publishing
Company, 479 p. - •
Terry, D.B,, and Shumeyko, R.D., 1988, Geologic correlation with elevated indoor radon
occurrence, Bergen County, New Jersey: Northeastern Environmental Science, v. 7,
p. 10. , , ."'... .
Turner-Peterson, C.E., 1980, Sedimentology and uranium mineralization in the Triassic-Jurassic
Newark Basin, Pennsylvania and New Jersey: in Turner-Peterson, C. (ed.), Uranium in .
Sedimentary Rocks, Application of the Facies Concept to Exploration: Society of Economic
Paleontologists and Mineralogists, Rocky Mountain Section, Short Course, Notes,
p. 149-175. , .
Turner-Peterson, C.E., Olsen, P.E., and Nuccio, V.F., 1988, Modes of uranium occurrence in
the Newark basin, New Jersey and Pennsylvania,: in Robinson, G.R., Jr., and Froelich,
AJ. (eds.), Proceedings of the Second U.S. Geological Survey workshop on early
Mesozoic basins of the eastern United States: U.S., Geological Survey Circular, 946,
• p. 120-124. , , ' , . '.;•
U.S. Soil Conservation Service, 1987, Soils: U.S. Geological Survey National Atlas sheet
38077-BE-NA-07M-00, scale 1:7,500,000.
Volkert, R.A., 1987, Geology, ground water occurrence^ and ground water quality in the Middle
Proterozoic rocks of the New Jersey Highlands: Proceedings of a short course on the
geology and hydrology of New Jersey, Part JJ, Geology and Hydrology of the New Jersey
Valley and Ridge, Highlands, and Lowlands Provinces, Rutgers University Cook College*
Continuing Professional Education, p. B-l—B-35.
Volkert, R.A., and Drake, A.A., Jr., 1990, New Geologic Map of the New Jersey Highlands:
Geological Society of America, Abstracts with Programs, v. 22, no. 2, p. 76.
IV-39 . Reprinted from USGS Open-File Report 93-292-B
-------
Wanty, R.B., Briggs, P.H., and Johnson, S.L., 1989, Influence of water-rock reactions on the
availability of radon-222 and its parent radionucUdes to ground water; an example from
the vicinity of Glen Gardner, N. J.: Geological Society of America, Abstracts with
Programs, v. 21, p. 73-74.
Witte, R.W., 1991, Deglaciation of the Kittatinny and Minisink Valley area of northwestern New
Jersey: Stagnant and active ice at the margin of the Kittatinny and Minisink Valley lobes:
Geological Society of America, Abstracts with Programs, v. 23, no. 1, p. 151.
Wolfe, P.E., 1977, The geology and landscapes of New Jersey: New York, NY, Crane Russak
Publishers, 351 p.
Young, D.A., 1971, Precambrian rocks of the Lake Hopatcong area, New Jersey: Geological
Society of America Bulletin, v. 82, p. 143-158.
Young, D.A., 1978, Precambrian salic intrusives of the Reading Prong: Geological Society of
America Bulletin, v. 89, p. 1502-1514.
Zapecza, O.S., and Szabo, Z., 1987 , Source and distribution of natural radioactivity in ground
water of the Newark Basin, New Jersey in B. Graves (ed.), Radon, radium, and other
radioactivity in ground water: Lewis Publishers, Inc., p. 47-68.
IV-40 Reprinted from USGS Open-File Report 93-292-B
-------
EPA's Map of Radon Zones
The USGS' Geologic Radon Province Map is;the technical foundation for EPA's Map
of Radon Zones. The Geologic Radon Province Map defines the radon potential for
approximately 360 geologic provinces. EPA has adapted this information to fit a county
boundary map in order to produce the Map of Radon Zones. . .
: The Map of Radon Zones is baaed on the same range of predicted screening levels of
indoor radon as USGS' Geologic Radon Province Map. EPA.defines the three zones as
follows: Zone One areas have an average predicted indoor radon screening potential greater
than 4 pCi/L. Zone Two areas are predicted to have an average indoor radon screening
potential between 2 pCi/L-and 4 pCi/L. Zone Three areas are predicted to have an average
indoor radon screening potential less than 2 pCi/L. , '
Since the geologic province boundaries cross state and county boundaries, a strict
translation of .counties from the Geologic Radon Province-Map to the Map of Radon Zones
was not possible. For counties that have variable radon potential (i.e., are located in two or
more provinces of different rankings), the counties were assigned to a zone based on the
predicted radon potential of the province in which most of its areajies. (See Part I for more
details.)
NEW JERSEY MAP OF RADON ZONES ' ,. ; .
The New Jersey Map of Radon Zones and its supporting.documentation (Part IV of •
this report) have received extensive review by New Jersey geologists and radon program
experts. The map for New Jersey generally reflects current State knowledge about radon for
its counties. Some States have been able to conduct radon investigations.in areas smaller than
geologic provinces and counties, so it is important to consult locally available data.
Several counties in New Jersey do not strictly follow the methodology for adapting the
geologic provinces to county boundaries. EPA and the State of New Jersey's Department of .
* Environmental Protection and Energy have decided to change several of the county zone
designations based on the increased radon potential that is demonstrated-by the elevated
indoor radon measurements. Cumberland, Gloucester, Salem, Camden, Burlington, Union,
Essex, Hudson, Passaic and Bergen have been designated as Zone 2 based on,this
supplemental data.
-Although-the. information provided in Part IV of tliis report ~ the State chapter entitled
"Preliminary Geologic Radon Potential Assessment.of New Jersey"— may appear to be quite
specific, it cannot be applied to determine th'e radon levels of a neighborhood, housing tract,
individual house, etc. THE ONLY WAY TO DETERMINE IF A HOUSE HAS
ELEVATED INDOOR RADON IS TO TEST. Contact the Region 2 EPA office or the
New Jersey radon program for information on testing and fixing homes. Telephone numbers.
and addresses can be found in Part II of this .report. • -..'•'• , '
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