SUGGESTED GUIDELINES FOR THE DISPOSAL OF
DRINKING WATER TREATMENT WASTES CONTAINING
NATURALLY OCCURRING .RADIONUCLIDES
U.S"Environmental Protection Agency
Office of Drinking Water
July 1990
Printed on Recycled Paper
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NOTICE
This document provides USEPA's guidance to public water
systems on issues not covered by existing regulations regarding
the disposal of wastes containing naturally occurring
radionuclides. The guidance is a general statement of policy.
It does not establish or affect legal rights or obligations. it
does not establish a binding norm and is not finally deter-
minative of the issues addressed. Agency decisions in any
particular case will be made applying the law and regulations on
the basis of specific facts and actual action.
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TABLE OF CONTENTS
Page
Introduction 1
Purpose and Scope 2
Summary of Treatment Technologies to Remove
Naturally Occurring Radionuclides 3
Radionuclide Characteristics of Wastes Generated
By Water Treatment Plants Removing Naturally
Occurring Radionuclides 6
Current Waste Disposal Practices 12
Rationale and Guidance for the Disposal of Wastes 13
-Liquid Wastes 13
-Solid Wastes 20
Recommended Radiation Guidance for Workers 33
1
References 38
Glossary 42
Appendix -. 44
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ACKNOWLEDGMENTS
Many individuals contributed to the preparation of this
guidance document. EPA acknowledges all participants who have
contributed valuable effort in writing, reviewing and finalizing
this material. Special regard is extended to the following
individuals:
Maze J. Parrotta, Chairman, Radionuclides Waste Disposal
Workgroup, USEPA Office of Drinking Water (ODW),
Wasn:ngton, D.C.
Michael Landrowski, USEPA Region IX, San Francisco
Paul B^.ngser, USEPA Office of the General Counsel
Franco^ae Brasier, USEPA Office of Drinking Water
John Davidson, USEPA Office of Policy Analysis
Peter Lassovszky, USEPA Office of Drinking Water
Jack Russell, USEPA Office of Radiation Programs
Bill Russo, USEPA Office of Radiation Programs
Stan Rydell, USEPA Region I, Boston
Alan Rubin, USEPA Office of Water Regulations and Standards
Betty Shackleford, USEPA Office of Solid Waste
Ben Smith, USEPA Office of Drinking Water
Tom Sorg, USEPA Office of Research and Development, Cincinnati
William Spell, Conference of Radiation Control Program
Directors, Inc.
James Westrick, USEPA Office of Drinking Water, Cincinnati
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•Btroduction
The naturally occurring radionuclides which are of concern
in drinking water are members of three radioactive decay series:
the thorium series, the uranium series and the actinium (U-235)
series. The members of these series are distributed throughout
the earth's crust and have existed since the formation of the
earth. Water supplies may contain high natural concentrations of
one or more members of these series. If treated, chemically or
otherwise, for potable water supply use, the possibility of
concentrating significant levels of naturally-occurring
ra ^.lonuclides exists, even if the treatment was not originally
designed or intended to remove radioactivity.
Not all radionuclides of these natural decay series are of
concern; most have not been found in sources of drinking water
supply at levels indicative of a risk to public health. Thorium,
for example, is virtually insoluble in waters that would be
considered for potable use. However, radium-228, a daughter
product of thorium, may occur in drinking water at levels that
would necessitate treatment for removal. The radionuclides of
most concern in drinking waters and in water treatment plant
wastes include: radium (Ra-226, Ra-228), uranium (U-234, U-235,
U-238), and radon (Rn-220, Rn-222), and the progeny (daughters)
of radon which include isotopes of polonium, lead, and bismuth.
The National Interim Primary Drinking Water Regulations(1)
(NIPDWR) established maximum contaminant levels (MCLs) for radium
and gross alpha radiation levels in drinking water. At that time
uranium and radon were excluded from the regulations due to
insufficient information on their occurrence and toxicity. The
Environmental Protection Agency (EPA) is revising the NIPDWR.
Under the new regulations, the National Primary Drinking Water
Regulations (NPDWR), MCLs for radium and gross alpha will be
revised and the EPA will establish MCLs for radon and uranium.
Water supply systems which distribute water containing
radium, radon or uranium above the MCL will have to implement
corrective measures to comply with the law. Treatment processes
such as ion exchange, lime softening, coagulation/filtration,
reverse osmosis and others are capable of effectively removing
the radionuclides of concern from drinking water. The handling
and disposal of the wastes generated by the treatment
technologies removing naturally occurring radionuclides from
drinking water pose significant concerns to the water supplier,
to local and State governments, and to the public at large.
This document addresses the management of radionuclide
wastes by first describing the potential sources of these wastes
(i.e., water treatment processes). Next there is a brief look at
some of the known information on the radionuclide composition of
fche associated treatment wastes. The text then describes
plausible disposal alternatives and provides background infor-
mation from related programs that should assist facilities in
selecting a responsible option.
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Purpose and Scope
The purpose of these suggested guidelines is to guide water
treatment facilities and State and local regulators toward safe
and responsible waste management practices for water treatment
plant wastes containing radionuclides at concentrations in excess
of background levels. This document is not intended to be
applicable to assessing requirements for hazards posed by other
chemical contaminants. Likewise, it is not intended to address
issues related to the use/disposal of sewage sludge. Separate
regulations addressing the use/disposal of sewage sludge at 40
CFR Part 503 were proposed for public comment (54 Federal
Register 5746; February 6, 1989).
At the present time there are no federal regulations
specifically addressing the disposal of wastes concentrated by
water treatment processes on the basis of their naturally
occurring radionuclide content. Unquestionably, waste by-
products produced by drinking water treatment facilities can be
of sufficiently high radioactivity to warrant disposal guidance.
Regulations and guidelines which address the handling and
disposal of wastes containing naturally occurring radionuclides
originating from industries other than water treatment have been
reviewed by EPA. A number of these sources have been utilized to
develop this guidance. They are referenced in the text.
This guidance is to provide assistance where gaps in
existing regulations may exist. States presently lacking
guidelines may wish to consider these guidelines as a starting
point for the development of their own policies regulating the
disposal of water treatment plant wastes containing naturally
occurring radionuclides. The States of Illinois and
Wisconsin(3) have developed disposal criteria of water treatment
plant wastes containing radium. The Conference of Radiation
Control Program Directors is developing suggested standards for
the disposal of naturally occurring radioactive wastes(4>.
Similarly, New Hampshire^' Colorado(6> and other states have
addressed the disposal of wastes containing naturally occurring
radionuclides.
On the Federal level, EPA's Office of Radiation Programs
(ORP) is expected to propose regulations controlling the disposal
of wastes containing Naturally-Occurring and Accelerator-Produced
Radioactive Material (NARM) with activities in excess of 2000
picocuries per gram (pCi/g), under the authority of the Toxic
Substances Control Act (TSCA), Section 6. NARM wastes of
concentrations above 2,000 pCi/g would be disposed of at Low
Level Waste Facilities or in a facility that is permitted by EPA
or a State to dispose discrete NARM under these regulations. At a
later date, EPA is considering the development of regulations
addressing the disposal and use of wastes that contain less than
2000 pCi/g of naturally occurring radionuclides, which may impact?
the guidance herein.
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.rnarv of Treatment Technologies to Remove Naturally Occurring
ionuclides from Drinking Water
There are a number of different treatment techniques
available to remove naturally occurring radionuclides of concern
from drinking water. Some of these technologies have been used
extensively to remove contaminants other than radionuclides from
water, while others are designed for the removal of a specific
radionuclide. Processes that have been demonstrated to be
effective for the removal of radionuclides include the following.
Cation Exchange for Radium Removal
Cation exchange using natural or synthetic resins to replace
calcium and magnesium ions is a commonly used technology. The
same ion exchange resins that are used to soften water can be
used to remove radium from the drinking water. Experience
indicates that a well operated ion exchange softening plant can
remove up to 97% of the radium from the drinking water*7'8'9'10'11'.
Since radium removal still takes place after the resin is
exhausted for hardness, regeneration of the resin to achieve good
hardness removal will also assure good radium removal.
Greensand Filtration for Radium Removal
This technology has been used to remove iron and manganese
?m the water. The iron and manganese is removed by passing the
r through a greensand filter of natural or synthetic media
after oxidation by potassium permanganate. This is a continuous
process, except when the process is interrupted by filter
backwash. Experience in Iowa(7) and Illinois*8' indicates that up
to 56% of the radium is also removed. In a more recent pilot
plant study, the removal of radium reportedly was improved to 90%
by passing the water through a detention tank after the addition
of potassium permanganate prior to filtration*16'.
Coprecipitation of Radium with Barium Sulfate
Addition of a soluble barium compound, such as barium
chloride, to the water containing radium and sulfates will cause
both the radium and barium to coprecipitate to form a highly
insoluble barium sulfate sludge containing the radium removed
from the water. This process has been primarily used to remove
radium from waste effluents. Experience with mine wastewaters
indicate that this process is capable of removing over 95% of
radium from water. At the present time , there is one full-
scale drinking water treatment plant, located in Midland, South
Dakota, that utilizes this process. Radium levels in the water
at this facility are reduced from 16 picocuries per liter (pCi/L)
to less than 1 pCi/L(18>.
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Anion Exchange for Uranium Removal
Anion exchange resins have been used to recover uranium from
mine process waters. Laboratory and field studies have verified
that anion exchange resins can be suitably adopted to remove
uranium from drinking water. Anion exchange resins have been
shown to remove over 95% of the uranium from water(10'12'13'U).
Anion exchange resins have very large adsorption capacity for
uranium, in some instances exceeding 20,000 bed volumes of
treated water(10).
Coagulation/Filtration for Uranium Removal
This treatment technology has been widely used by the water
treatment industry to make the water suitable for potable use.
Although this technology is not applicable to the removal of
radium from drinking water, limited information indicates that
under suitable operating conditions it can be effective for the
removal of uranium. Results of laboratory studies have demon-
strated that the effectiveness of iron coagulants and alum to
remove uranium from water is highly sensitive to pH(12>13). The
removal efficiency at a specific pH level depends on the
prevailing charge on the floe and the uranium species present.
Best removal efficiencies, 85 to 95%, have been encountered at pH
levels of 6 and 10. Use of coagulant aids, such as polymers has
resulted in improved removal of uranium in an operating water
treatment facility at Arvada, Colorado'13'.
Lime Softening for Radium and Uranium Removal
Lime softening is a commonly used process to remove hardness
from drinking water. Addition of lime removes hardness by the
formation of insoluble calcium carbonate and magnesium hydroxide.
It has been shown that at elevated pH levels lime softening is
very effective in the removal of radium and uranium from drinking
water. Experience in the field and the laboratory demonstrated
that lime softening can remove 75 to 90% of the radium from
(8 O 11\
drinking water provided pH levels are maintained above 10 ' • .
Laboratory studies indicate that lime softening is 85 to 90%
effective in the removal of uranium from drinking water. The
removal efficiency can be improved up to 99% by the presence or
the addition of magnesium carbonate to the water '.
Reverse Osmosis for Radium and Uranium Removal
Reverse osmosis is a process that is commonly used in areas
where water has high total dissolved solids concentrations. This
process uses semi-permeable membranes that allow the passage of
water but reject the dissolved salts. Pressure is required to
force the water through the membranes. The process is
continuous. The treated, or "recovered," water is passed to
storage and to distribution for potable use, and the rejected
concentrate is discharged as a concentrated liquid waste stream.
Reverse osmosis has been shown to be highly effective for
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removing inorganic contaminants, including heavy metals and
radionuclides such as radium and uranium. Reverse osmosis can
remove 87 to 98% of radium and 98 to 99% of uranium from drinking
water(Uf .
Granular Activated Carbon for Radon Removal
Granular activated carbon (GAC) has been used for the
removal of organic contaminants and for taste and odor control.
Recently this technology has been used for the removal of radon
from drinking water. GAC treatment for radon removal was found
to be attractive because most of the adsorbed radon decays within
the carbon bed before breakthrough. Because of radon decay,
effective life of the carbon bed is extended many times over the
life indicated by the adsorption isotherm. However, the decay of
radon on the GAC media results in the build-up of radon-222 decay
products (see p. A-12) such as lead-210. and radiation of low-
level gamma activity near the GAC unitc . The build-up of lead-
210 in GAC has been estimated for various levels of influent
radon concentration, and the result is shown graphically in the
Appendix, p.A-6. The extent of this problem, including the
disposal of spent GAC media containing radionuclides, should be
given full consideration before implementing this technology.
Pilot plant studies have indicated that activated carbon will
also capture some uranium and radium from drinking water, which
further underscores the need to exercise care in the planning of
treatment and waste disposal options. Dependent on design,
granular activated carbon is capable of removing up to 99% of
radon from drinking water.
Aeration for Radon Removal
Various aeration processes, such as packed tower aeration,
slat trays, diffused aeration and spray aeration are capable of
removing from 65% to over 99% of radon from drinking water,
depending on the specific design parameters". These processes
have been used widely for the removal of volatile contaminants
and the oxidation of inorganic contaminants such as iron in
drinking water. Some States may limit the use of aeratic \
technologies for radon removal because of concern for huirw.n
exposure due to air emissions. However, preliminary analysis by
EPA indicates that an aeration unit which emits radon a * allows
adequate dispersion of the gas in ambient air would not esu]t in
a significant health risk to the local population. Loca
limitations, concentration of radon in water, emission t^tes,
cost of treatment alternatives, and other site-specific factors
should be given full consideration before implementing any
technology for radon removal.
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Other Technologies
There are other treatment technologies that are capable of
removing radionuclides from water. However, they have not been
extensively used in drinking water treatment, or have been used
industrially or only experimentally. These technologies include
special chemically-selective sorbents(16>21>22) such as acrylic
fibers or resins impregnated with manganese dioxide which remove
radium from water, and electrodialysis. Electrodialysis has been
applied to mining industry wastes containing radionuclides.
Limited experimental studies have shown that activated alumina is
capable of achieving good removal of uranium from drinking water.
Cation exchange resins other than sodium ion exchange (such as
hydrogen-form and calcium-form exchangers) have also demonstrated
effective radium removal capability(23>.
Radionuclide Characteristics of Wastes Generated by Water
Treatment Plants Removing Naturally Occurring Radionuclides
The Resource Conservation and Recovery Act (RCRA) prescribes
a fully integrated set of regulations governing the generation,
management, and disposal of "solid" wastes which meet criteria
for designation as hazardous wastes. In addition, some states
impose additional restrictions on solid wastes which do not meet
criteria for designation as hazardous under RCRA. Nothing in
this manual should be construed to limit in any fashion the
requirements imposed by such programs. This manual is intended
to address management in the absence of regulation. For the
purpose of these guidelines "solid" and "liquid" wastes
containing radioactivity are defined as follows:
Solid wastes will mean the sludges which result from
settling or concentration of solids by mechanical or non-
mechanical means, and the media such as ion exchange resin,
filter bed materials, granular carbon or selective sorbents which
are by-products of water treatment and contain residual
radioactivity.1
Liquid wastes will mean the rinse and backwash waters,
regenerant solutions, supernatants, reject waters, waters removed
during solids concentration procedures or other wastewaters which
are the by-product of water treatment and contain residual
radioactivity.
In general, the amount of any contaminant contained in the
wastes produced by the various treatment processes depend upon a
number of site-specific factors such as:
• Concentration of contaminant in raw water
* Removal efficiency of the treatment process
NOTE: This definition of "solid waste" is distinct from
that which is used under the Resource Conservation and
Recovery Act (RCRA).
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' Frequency of regeneration of exchange resins
• Frequency of filter backwash
8 Frequency of replacement of the carbon or
other sorbent bed
0 Loading capacity of the resin or sorbent
0 Coagulant or lime dosage rate and raw water pH
° Radionuclides retained in sludge and in supernatant
0 Reverse osmosis membrane type and operating pressure
The contaminants removed from water are essentially
concentrated in the wastes produced by the treatment process.
This concentration of contaminants can result in wastes
containing orders of magnitude higher levels of constituents.
As a consequence, wastes require special consideration of the
potential hazards they may pose. This section deals solely with
the radiological properties of water treatment plant wastes.
The following is a more detailed description of the wastes
produced by the various water treatment processes that remove
naturally occurring radionuclides.
Ion exchange wastes
The wastes produced by ion exchange treatment include liquid
waste containing brine, rinse and backwash water, and
contaminants stripped off the resin. In addition, the resin
itself is a solid waste containing the contaminant exchanged. The
amount of radium or uranium contained in the resin is dependent
upon its loading capacity and whether it is disposed prior to or
after regeneration. The volume of waste stream produced by the
cation exchange process to remove radium from drinking water
typically ranges between 2 to 10% of the product water. The
concentration of the radionuclides in the waste stream produced
by the ion exchange process depends upon the amount of radio-
nuclides removed from the resin, the amount of regenerant used
and the frequency of regeneration. In a study performed in Iowa,
the radium levels in the waste streams from the regeneration
process were observed to range from 110 to 530 pCi/L (with a peak
recorded at 3500 pCi/L) in the softener rinse and brine* . Other
data, provided by Wisconsin, indicated average and peak
concentration levels of radium in regenerant wastewater of 23.1
pCi/L and 158.2 pCi/L, respectively. The radioactive buildup in
a cation exchange resin removing radium in the same water
treatment facility was 8.70 pCi/g of combined radium.
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At two facilities employing zeolite softeners, in Illinois
(see App. A, page 2b) , combined radium concentrations in filter
media were measured at 16 pCi/g (dry) and 58 pci/g (dry). The
difference in these two values may be due to the respective times
that the media were in service: 2 years and 10 years.
Anion exchange resins have been found to have a very high
loading capacity for uranium. Experience indicates that these
resins can treat as much as 20,000 bed volumes of water between
regenerations'1 }. Consequently,- the regenerant liquid wastes
will contain high levels of uranium. Experience in a pilot plant
demonstration at a well site showed that, with an influent
uranium concentration of approximately 150 pCi/L, an average
waste stream concentration of 2 mg/L (or 1350 pCi/L) and as much
as 25 mg/L (or 17,000 pCi/L) of uranium would be contained in the
regenerant waste stream, if the resin is operated until
breakthrough<13). Because of their affinity for uranium, high
radioactive buildups will occur in anion exchange resins.
Additional information regarding radium and uranium in ion
exchange wastes are shown in the Appendix, pages A-4 and A-2a.
Lime softening wastes
The wastes generated include lime sludge which is precipi-
tated during the process of removing the radium or uranium.
Additional wastes are generated by the backwashing of the
filters. Liquid wastes include the supernatant from the sludge
and filter backwash. The concentrations of the radium or uranium!
in the lime sludge and the filter backwash sludge may vary
between individual water treatment plants, dependent upon the
concentration of the radionuclides in the source water and the
lime dosage added during the treatment. Experience with
operating lime softening facilities indicate that typical radium
concentration levels range from 1,980 to 2,500 pCi/L in the lime
softening sludge, 6 to 9 pCi/g in the dried sludge and 6 to 50
pCi/L in the filter backwash water. Radium levels in the
supernatant over settled sludge was found to range between 21 and
24.4 pCi/L<24>. For additional data refer to the Appendix. There
are no operating plant data regarding the levels of uranium in
the wastes generated in a lime softening water treatment
facility.
Coagulation/filtration wastes
The wastes generated in this process include iron or alum
sludges from the contact and settling basins and from the filter
backwash. The supernatant from this sludge comprises a liquid
waste. Additional liquid waste is generated when the sludge is
concentrated prior to disposal in a landfill. The amount and
activity of contaminants such as uranium in the sludge, is
dependent upon the removal efficiency of the process, t-the
concentration of contaminants in the raw water, and the dosage o&»
coagulant applied. Uranium concentration in sludges has been
estimated to be from 10,000 to 30,000 pCi/L for uranium raw water"
concentrations in the range of 30 to 50 pCi/L.
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Reverse osmosis and electrodialysis wastes
The wastes from these processes are the reject streams,
which are continuously generated during the treatment process.
The amount of radionuclides in the reject stream is dependent
upon the operating removal efficiency as well as the influent
concentration levels. For instance, if a reverse osmosis (RO)
plant removes 98% of the radionuclides from the drinking water
and rejects 50% of the source water as waste, the concentration
level of radionuclides in the rejected waste water would be 1.96
times greater than the concentration levels of radionuclides in
the raw water. Results of studies by EPA indicated that radium
concentration levels in the reject waters of RO facilities
removing radium from drinking water ranged from 7.8 to 37.9
pCi/L<15). These results are shown in the Appendix (page A-3) .
Greensand filtration wastes
The wastes generated by this process include sludge and
supernatant from the filter backwash, and eventually the
greensand media. Concentration levels of radium in the filter
backwash have been found to range between 65 and 169 pCi/L<25>.
Concentrations of radium in natural greensand media were found,
at one plant (see App. A, page 2b), to range from 28 to 46 pCi/g
(dry) of Ra-226, and at 59 pCi/g (dry) of Ra-228,
Wastes from co-precipitation of radium with barium sulfate
The wastes generated by this process include barium sulfate
precipitant sludge containing the radium removed from the water,
filter backwash, and supernatant from the sludge<26).
Selective sorbent wastes
Selective sorbents used for removal of radium from drinking
water are not regenerated. Experience indicates that the sorbent
loading capacity can produce radium concentration levels within
the media of up to 110,000 pCi/g, dry weight(23>. A recent EPA-
sponsored study found that a particular radium-selective
adsorbent, upon exhaustion, contained 3,600 pCi/g radium <22).
Granular activated carbon (GAG) wastes
GAG that is ussd to remove radon from drinking water will
retain and accumulate the decay products of radon( }, which
include radioactive isotopes of polonium, lead, and bismuth. In
addition, GAG systems in New Hampshire and Maine have shown that
GAG will remove uranium as well as radon from drinking water.
Preliminary data from New Hampshire suggest that GAG also removes
radium. According to these data, the observed uranium
concentration on the carbon was 258.5 uCi/m3 ( , or about 580
pCi/g. The amount of radium and uranium (if present) retained by
the GAG depends upon its loading capacity. This loading capacity
is reached long before th® carbon is expected to be replaced on
the basis of radon adsorbed.
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However, because of its relatively long (20 year) half-life
and ability to stay within the pores of GAC media, lead-210
levels in a carbon bed will increase during the service life of
the carbon. The amount of lead-210 retained by GAC beds removing
radon from drinking water has been estimated (as shown in the
Appendix, page A-6, for a small GAC unit). Lead-210 is a beta
particle emitter that decays to bismuth-210(a beta emitter),
polonium-210(an alpha emitter) and lead-206, which is stable and
non-radioactive. Where relatively small amounts of radon gas is
present in water, it is estimated that it may be several years
before the capacity of a GAC bed for radon decay products is
exceeded. In instances where organic contaminants are present in
the water, the length of the service life of the carbon bed will
be governed by the breakthrough of the organic contaminant.
The following table is a summary of the types of wastes that
would be generated by various drinking water treatment
techniques.
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TABLE 1
Summary of Treatment Technologies and Wastes Produced During
Removal of Naturally Occurring Radionuclides
From Drinking Water
TREATMENT
TECHNOLOGY
CONTAMINANT
REMOVED
WASTE(S) PRODUCED*
Cation
Exchange
Anion
Exchange
Lime
Softening
Coagulation/
Filtration
Reverse
Osmosis
Greensand
Filtration
Coprecipitation
with BaSO,
Granular
Activated
Carbon
Selective
Sorbents
Aeration
Radium
Uranium
Radium
Uranium
Uranium
Radium
Uranium
Radium
Radium
Radon
Uranium
Radium
Radon
Rinse and backwash water,
brine regenerant solution.
Rinse and backwash water,
brine regenerant solution.
Sludge from settling tanks,
filter backwash, supernatants.
Sludge from settling tanks,
filter backwash, supernatant
from settling or concentrating
sludge and filter backwash.
Reject water.
Solids and supernatant from
filter backwash.
Sludge from settling tanks,
filter backwash, supernatant
from settling or concentrating
sludge and filter backwash.
Granular activated carbon
media.
Selective sorbent media.
Radon released into air, or
radon decay products accumu-
lated on off-gas contactors
(i.e.. GAP
*NOTE: Wastes containing radioactivity may also include filter
material, exchange resins, and other disposed materials.
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Current Waste Disposal Practices
Traditionally, waste streams produced by water treatment
have been discharged into sanitary sewers or receiving waters,
injected into deep wells or otherwise disposed of underground,
and sludges either disposed of in landfills or spread on land. In
many areas State and local laws already limit the discharge of
wastes containing radionuclides into the environment. There are
federal regulations that are applicable to the discharge and
disposal of wastes into navigable waters, on land, or by deep
well injection., In some instances, treatment of waste streams
may be required before ultimate disposal by controlled discharge.
Where disposal of water treatment wastes containing radio-
nuclides is restricted, some waste generators have resorted to
the use of evaporating lagoons. However, this method is only
practical if sufficient land is available at low cost and the
evaporation rate exceeds the rainfall. Where land is not
available, sludges generated by the treatment processes have been
dewatered by centrifugation or by vacuum filtration. In many
instances, if good separation occurs, the supernatant from the
settling tanks has been recycled to the intake of the water
treatment plant. This practice reduced the amount of wastes to
be handled and disposed.
Concentration of wastes reduces the volume that has to be
ultimately disposed. However, at the same time, concentrations
of radionuclides and other contaminants in wastes increase.
Disposal of concentrated wastes and high capacity resins or
sorbents that are not regenerable sometimes requires special
handling and disposal because of the accumulation of high
concentrations of radionuclides. Similar precautions have been
warranted with the handling and disposal of spent-granular
activated carbon that has been in service for extended periods
for the removal of radon from drinking water. Accumulation of
radon decay products, and other radionuclides present in the
water such as uranium, have contributed to increased levels of
radioactivity in the carbon bed.
For small water supply systems, disposal of wastes generated
by water treatment has been more difficult. A large number of
small communities do not have resources to build new waste
handling facilities, or are not located on sewage systems. Some
small systems dispose of water treatment by-products into septic
tanks (which is not an EPA suggested disposal method). Such
septic systems are generally not designed to handle the brines or
other wastes generated by water treatment facilities removing
radionuclides from water. Some communities have wastes hauled
away for disposal at an appropriate site.
Table 2, below, summarizes some of the principle disposal
methods used by water treatment facilities with respect to their
wastes containing natural radioactivity.
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TABLE 2
Summary of Current Disposal Practices of Water Treatment
Facilities Removing Naturally Occurring Radionuclides
LIQUID WASTE DISPOSAL
Direct discharge into storm sewers or surface water
Discharge into sanitary sewer
Deep well injection
Drying or chemical precipitation
SOLID WASTE DISPOSAL
Temporary lagooning (surface impoundment)
Disposal in landfill
a) disposal without prior treatment
(resins, filter media, GAG)
b) with prior temporary lagooning
c) with prior mechanical dewatering
Application to land (soil spreading/conditioning)
Disposal at State-licensed low level radioactive waste
facility
Rationale and Guidance for the Disposal of Wastes Containing
Naturally Occurring Radionuclides Generated by Water Treatment
Plants
Federal, State and local laws and regulations governing the
disposal of water treatment wastes must be complied with when
following these guidelines. Regulations that are more stringent,
limiting the options for the disposal of water treatment wastes
based upon its radioactivity or hazardous nature, supersede the
guidelines recommended below.
Liquid wastes
The following is a discussion of the federal standards
applicable to the disposal of radionuclide-bearing wastes. The
rationale used in formulating the disposal guidelines and
respective concentration limits is also presented.
° Disposal into storm sewers and surface waters
Section 402 of the Clean Water Act requires that dischargers
of pollutants to navigable waters obtain National Pollutant
Discharge Elimination System (NPDES) permits containing, at a
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minimum, technology-based effluent limitations reflecting various
levels of wastewater treatment and, where necessary, more
stringent limitations necessary to assure attainment and
maintenance of State water quality standards. EPA has not
"promulgated any rule establishing technology-based effluent
limitations applicable to water treatment plants nationwide. In
the absence of such a categorical standard, limitations are
established on a case-by-case basis using best professional
judgment. After determination of minimum technology-based
requirements, the effect(s) of discharge on the receiving water
is determined, and if necessary more stringent limitations are
established to protect the receiving water quality. In certain
States, water quality standards may include specific criteria for
radionuclides. State water quality standards that require more
stringent discharge limitations must be reflected in any NPDES
permit.
The discharge of water treatment plant wastes into a storm
sewer through to surface waters is subject to the same NPDES
regulatory framework as a discharge directly to surface waters.
As part of the NPDES permitting process, the flow and geometry of
a receiving storm sewer and surface waters as well as potential
uses of the surface water (e.g. drinking water, agriculture)
should be studied. It should be determined that prevailing
conditions of flow and geometry within the storm sewer and the
receiving water body would prevent the buildup of radionuclides
in the water column and/or sediment and would allow adequate
downstream mixing. Based on the above site conditions, a State
or other regulatory agency may use its discretion in determining
a limiting concentration, such as a drinking water MCL, or a
percentage of the background concentration(s) of radionuclides,
such as 10 percent, that would limit the increase of
radionuclides in the water body (and/or the sediments) due to the
discharge of water treatment wastes.
If the conditions of flow and geometry are not adequate to
prevent a buildup of radionuclides in the storm sewer, the
surface water or sediments, to within the limit set by the
regulator, then other solutions need to be studied; these may
include additional waste treatment, waste storage and controlled
discharge measures, in order to produce a waste stream that could
meet the in-stream requirements set by the regulator. Otherwise,
discharge to surface waters should not be allowed and other
options would need to be considered.
° Disposal into sanitary sewers
There are no Federal regulations which specifically control
the discharge of wastes from water treatment plants into sanitary
sewers. However, regulations governing discharges to sanitary
sewers are contained in the General Pretreatment Regulations at
40 CFR Part 403. The pretreatment regulations prohibit discharge
to sewers that would cause a municipal wastewater treatment plant
to violate an NPDES permit, or that would interfere with
wastewater treatment operations or sludge disposal. In addition,
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States or localities may establish more stringent limitations on
the discharge of wastes from water treatment plants into the
sanitary sewer, or may require pretreatment of the waste prior to
release into the sanitary sewer. State or local regulations
limiting the discharge of water treatment wastes containing
naturally occurring radionuclides into sanitary sewers would
govern those discharges.
Beyond such regulations, EPA recommends that all discharges
to sanitary sewers meet regulations established by the Nuclear
Regulatory Commission (NRC) for NRC licensees. NRC limits the
discharge of wastes containing radioactive materials into
sanitary sewers. These are codified in 10 CFR Part 20 (30>. Table
I of Appendix B to Part 20 is incorporated in this guidance. In
addition to the specific standards prescribed by NRC in 10 CFR
20.1 and 20.303, facility operators should make every reasonable
effort to reduce the release of radioactive materials into the
environment to as low a level as reasonably achievable (as NRC
licensees are required, under Part 20). "As low as reasonably
achievable" means taking into account the state of technology to
reduce discharge of contaminants, the cost of improvements and
benefits to public health and safety. In the context of water
treatment plant operations, EPA believes that this means less•
than a 10 percent increase in sewage radioactivity levels.
The following are suggested guidelines based on the above-
cited NRC requirements:
a) The daily quantity of soluble radium-226, diluted by the
average daily quantity of water treatment wastes released
into the sewer, should not exceed 400 pCi/L.
b) The daily quantity of soluble radium-228, diluted by the
average daily quantity of water treatment wastes released
into the sewer, should not exceed 800 pCi/L.
c) The daily quantity of soluble uranium (natural), diluted by
the average daily quantity of water treatment wastes
released into the sewer, should not exceed 1 microcurie per
liter (uCi/L).
d) The above concentrations, once determined, should be applied
to the following relationship. The sum of the ratios should
not exceed "unity", as follows:
£Ra-226 + gRa-228 + CU < 1 where:
400 800
cRa-226 = average daily concentration of soluble radium-226
in the wastewater (pCi/L)
cRa-228 = average daily concentration of soluble radium-228
in the wastewater (pCi/L)
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"~U = average daily concentration of soluble uranium in
the wastewater (uCi/L)
Soluble means readily dispersible in the ambient water or
wastewater (the NRG does not allow discharge to sewer unless
the materials discharged are soluble in water).
Another NRC standard (§20.303(c)) limits the annual quantity
of radioactivity disposed of via sanitary sewers. This may be
applied to water treatment wastes as a guideline:
e) The gross quantity of radioactive material released by the
facility into the sanitary sewer should not exceed 1 curie
per year.
If accumulation of radioactivity in the sanitary sewage
distribution system or in the sewage treatment facility (or
publicly owned treatment works) is observed, discharge of radio-
active wastes into the sanitary sewer should be discontinued
until radiation exposures and possible hazards to personnel
repairing sewage pipelines are evaluated. Discharge of wastes
containing radionuclides into the sanitary sewer will result in
the accumulation of radionuclides in the sludges produced by the
wastewater treatment plant, as shown in the Appendix (page A-5).
Subsurface disposal
Under Part C of the Safe Drinking Water Act (SDWA) EPA is
required to promulgate minimum requirements for effective
Underground Infection Control (UIC) programs to prevent
endangerment of underground sources of drinking water by
subsurface emplacement of fluids through wells. These minimum
requirements are currently promulgated at 40 CFR Parts 124, 144,
145, and 146.
The regulations may be implemented by States that have
adopted requirements at least as stringent as the Federal
requirements and have been given primary enforcement respon-
sibility for the UIC program (Primacy States). For States that
do not have primacy, EPA has promulgated State-specific
regulations that are implemented by EPA regional offices. State-
specific regulations have been codified at 40 CFR Part 147 and
Parts 124, 144 and 146.
A drinking water treatment plant owner interested in
disposing of wastes containing radionuclides into an injection
well in a Primacy State should consult with the appropriate State
Agency first since State regulations may be more stringent than
the Federal requirements and may ban such practice. The plant
owner in other States should consult with the appropriate UIC
Regional Branch office (EPA) before deciding to dispose of wastes
containing radionuclides into an injection well in accordance
with a method recommended below.
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Under the Federal requirements, regulation of .atei
treatment plant wastes containing radionuclides depends on the
concentrations of radionuclides present. Furthermore,
requirements are specified for shallow and for deep well
injection. Shallow wells are defined as those above, or in, an
underground source of drinking water (USDW). USDWs and injection
wells are defined very broadly. A well is any bored, drilled, or
driven hole where the depth of the hole is greater than tne
largest surface dimension. The definition includes septic
systems and cesspools used for disposal of wastes. A USDW is an
aquifer or its portion which supplies any public water system; or
which contains sufficient quantity of water to supply a public
water system and supplies drinking water for human consumption,
or contains fewer than 10,000 mg/L TDS.
Radioactive wastes are treated differently than nonradio-
active wastes under the UIC program. As defined in 40 CFR
§144.3, "Radioactive Waste means any waste which contains
radioactive concentrations which exceed those listed in 10 CFR
Part 20, Appendix B, Table II, Column 2." The concentration for
radium-226 is currently listed as 30 picocuries/L, while the
radioactive concentration for uranium (natural) is 30,000
picocuries/L.
Radioactive wastes as defined by the UIC program (i.e.,
wastes containing Ra-226 greater than 30 pCi/L, Ra-228 greater
than 30 pCi/L; U greater than 30,000 pCi/L) would not be dis-
posed in a shallow well as defined above. Shallow injection of
radioactive wastes (i.e., injection above or into an underground
source of drinking water, or USDW) is a banned practice under the
UIC program. The definitions of USDW and shallow injection would
virtually eliminate any shallow disposal of radioactive waste
that may be contemplated.
Deep well disposal of radioactive waste below a USDW is
considered a Class V well and is under study by EPA as part of
the Class V regulatory development effort. At this time the EPA
is not prepared to make any recommendations regarding these
wells.
The following is suggested guidance for nonradioactive
wastes as defined by the UIC program (i.e., wastes containing
less than 30 pCi/L Ra-226; less than 30 pCi/L Ra-228; less than
30,000 pCi/L uranium):
Well injection of nonradioactive drinking water treatment
plant wastes beneath the lowermost USDW is classified as Class I
practice, provided the waste contains no other hazardous
components. EPA recommends disposal of nonradioactive waste
through a Class I well because these wells must be permitted, and
current permitting requirements for these wells are extensive and
adequately protect USDWs and human health.
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(NOTE: Wells used for shallow injection of wastes deemed
nonradioactive by the injection program are considered Class V
wells. As explained above, the EPA is not making recommendations
regarding Class V wells at this time.)
Other options
If, due to the properties of the liquid wastes or due to
local regulatory restrictions, a liquid waste containing
naturally occurring radionuclides cannot be processed by the use
of one of the above methods, then the treatment operator may need
to choose from other treatment -or disposal options, such as
evaporation of liquid wastes, sand drying or lagooning, chemical
precipitation of contaminants, or other solids separation
techniques. Other State regulations may apply to these
practices. At a minimum, no practice should be less
environmentally protective than the above mentioned options. For
instance, lagooning of radioactive wastes would be analogous to
shallow well injection, if practiced in an unlined unit. Lagoons
or other impoundments should at a minimum be lined to prevent
infiltration. Systems desiring to evaporate a radioactive waste
should design and operate the unit to ensure isolation of the
waste from the water table. In every case, residual solids
should be disposed of as recommended in the following section.
Figure 1, below, contains a flow diagram which summarizes
the decisions per EPA suggested options for the disposal of
liquid wastes which contain naturally occurring radionuclides.
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Figure 1
Summary of Disposed Alternatives For Water Treatment Plant Liquid Wastes
Containing Natural Radioactivity
|WTP LIQUID WASTES
initial monitoring
for radionuclides
NPDES permit
obtained. Stream
flow will prevent
buildup in water
and sediment to
within a State
determined limit
Ra-226<400 pCi/L
Ra-228 <800 pCi/L
•total U(uCi/L) <1
Ra-226+Ra228-HJ <1
"400"SET
Yearly TbtaKl Curie
AND, no accunulation
of radioactivity in
sewerage system
Discharge direct to storm
sewer OR to surface water
YES
Subsurface Disposal
Option -
Is waste classified as
radioactive under
40 CFR 144.3?
NO
Injection below formations
containing USDW**- this is
subject to 40 CFR 144.6(a)(2)
and 144.12(c)
Sanitary
Sewer, NRC
Requirements
at 10 CFR 20
Residual solids
disposal as guided
in next section
Evaporation, drying
(lined facilities),
Precipitation, or
Other treatment
YES
vO
I
Shallow injection is
banned. Injection below
USDW under review for
regulatory action.
* These concentrations are the activities diluted by average daily quantity of water treatment plant
liquid waste, per requiranents in 10 CFR 20.
**USUW is underground source of drinking water.
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Solid Wastes
All natural materials contain radioactivity. Based on
sampling at 200 locations, as reported by the National Council of
Radiation Protection ( ', the average concentration of uranium in
soil is about 66 Bacquerel/kg, or 1.8 pCi/g. Unfortunately,
average levels of radium in soil are frequently associated with
high risks from indoor exposures to radon, a gaseous radioactive
decay product of radium. For this reason, wastes that contain
only a few times the average background concentration of radium
should not be disposed of indiscriminately. Because the half-
life of these radionuclides is long, they represent essentially
permanent contaminants in the environment. The half-lives of
some thorium and uranium isotopes are tens of thousands to
billions of years (see Appendix, p. A-10). Special care in the
management of these wastes is essential. The following
discussion summarizes existing regulations, and then identifies
acceptable management practices.
The following disposal guidance is based solely on the
radioactivity of these wastes and does not address any other
potentially hazardous substances they may contain. In regard to
the chemical toxicity of natural uranium, it is believed that at
low level exposures radiotoxicity dominates. According to
information contained in International Commission on Radio-
logical Protection, Publication 30 (1979), it is at high levels
of exposure (not the subject of this document) where chemical
toxicity becomes a dominating factor.
A. Existing Regulatory Framework
Disposal of solid wastes containing naturally occurring
radioactivity, including water treatment wastes, falls under the
authority of the Resource Conservation and Recovery Act (RCRA).
RCRA section 1004(27) specifically refers to sludge from water
supply treatment plants, and it explains that coverage extends to
solid, liquid, semi-solid, or contained gases from various
operations. However, the definition of solid waste on page 6 of
this document is a narrower definition than that used in RCRA.
Under RCRA a "solid waste" is any discarded material that is not
excluded under 40 CFR sections 261.4(a) or 260.30 and 260.31,
which are variance provisions. Under § 261.4(a) "source, special
nuclear and by-product materials," as defined by the Atomic
Energy Act of 1954, as amended, 42 U.S.C. 2011 et sea.. are
excluded from the definition of solid waste under RCRA but are
subject to Atomic Energy Act provisions.
Wastes meeting the RCRA definition of solid waste are also
evaluated against a classification scheme. RCRA solid wastes are
hazardous wastes if they exhibit specified characteristics of
ignitability, corrosivity, reactivity, or toxicity, as defined
under 40 CFR 261, Subpart C, or if they are listed as hazardous
in Subpart D. Radioactivity in solid wastes from drinking water
treatment are not currently regulated as "hazardous" under these
RCRA criteria. It should be noted, however, that if there is
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another contaminant in a particular waste it may cause the waste
to be classified as hazardous under RCRA. Where radioactive waste
is mixed with RCRA hazardous waste, the mixture is subject to
RCRA Land Disposal Restrictions (40 CFR Part 268) which would
limit the available disposal options.
RCRA Subtitle C regulation triggers stringent management
standards and waste manifesting requirements, and restricts
disposal options to certain permitted units. Management of RCRA
hazardous wastes is beyond the scope of this guidance.
Radioactive wastes should not be mixed with RCRA hazardous wastes
prior to disposal because RCRA management requirements may unduly
complicate disposal of the water treatment wastes.
If the water treatment processes covered by these guidelines
are sub-units of facilities subject to RCRA permitting, the
facility may need to monitor and take remedial measures for a
larger class of hazardous constituents. EPA is currently
developing rules, under Subpart S, on corrective action
requirements for solid waste management.
Radioactive releases from wastes could cause a water
treatment plant using on-site waste management to violate the
State groundwater protection criteria adopted in response to the
criteria of 40 CFR 257. The Part 257 criteria are applicable to
radium and gross alpha particle activity (excluding radon and
uranium) as well as for other contaminants for which drinking
water MCLs have been promulgated by EPA. Facilities that violate
the criteria in Part 257 are deemed to pose a reasonable proba-
bility of adverse effect to human health or the environment. For
the above mentioned reasons, it is clear that considerable care
should be exercised when disposing of these wastes in any on-
site operation. The seeming attraction could result in greater
subsequent expenditures if contaminant releases occur.
Regulations are also to be promulgated in regard to off-
site management of solid wastes in municipal solid waste
landfills. EPA proposed new standards under the authority of
RCRA and §405(d) of the Clean Water Act, at 40 CFR 258 (53
Federal Register 33314, August 30, 1988), to apply to landfills
that accept household waste and other types of nonhazardous
waste, including sewage sludge. These regulations would exclude
municipal solid waste landfills from the criteria in Part 257,
and would apply new Part 258 criteria to municipal landfills
which accept both household wastes and sewage sludges. Part 258
regulations would prohibit the disposal of free liquids in
municipal landfills and could involve a water treatment facility
in a cleanup if corrective action were required.
In addition, EPA promulgated in the Federal Register
(December 15, 1989) disposal standards under Section 112 of the
Clean Air Act at 40 CFR 192<32) specifically for the cleanup and
disposal of uranium mill tailings, a sand-like material that
contains radium, uranium, and thorium, usually in concentrations
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of one hundred to a few thousand pci/g, and nonradioactive toxic
substances. The disposal standards apply to the long-term
control of bulk tailings. The disposal standards for uranium
mill tailings may provide useful guidance for the disposal of
water treatment wastes that have radium concentrations from
several tens to several hundreds of pCi/g (although
concentrations of the latter magnitude are expected to be rare in
water treatment wastes).
Tailings, a residue from the partial extraction of uranium
from ore, are deposited in very large "piles" adjacent to uranium
mills. The standards (summarized in Appendix A, pages 14 through
16) serve two major objectives: (l) to clean up tailings that
nature or people have removed from the piles, in order to reduce
existing and potential hazards they may pose, and (2) to dispose
of tailings piles by stabilizing them so as to minimize their
emissions and the potential for human misuse of tailings.
Some States also have programs which license or permit
Naturally-Occurring and Accelerator-Produced Radioactive Material
(NARM) disposal sites. These programs may place limits on the
disposal of radium and/or uranium.
One State, Utah, currently has a licensed disposal
facility for naturally occurring radioactive materials (NORM).
Finally, in 1990 EPA expects to propose, under the authority
of the Toxic Substances Control Act, Section 6, standards for
low-level waste* } that will set requirements for disposal of,
among other things, wastes containing more than 2,000 pCi/g of
naturally occurring radioactive materials.*
B. Disposal Rationale for Radium-bearing Solid Wastes
Minimizing future hazards is essential for radium-bearing
materials because the potential indoor radon hazard is so large.
A radium level in soil of about 1 pCi/g may be associated with an
average indoor radon level of about 1 pCi/L, and a lifetime lung
cancer risk of about 5 x 10"3. Considering house-to-house
variability, several times this risk level is common, even where
the soil radium concentration is not above average. Other
parameters being equal, indoor radon levels will increase in
proportion to soil radium concentration. Radon releases from
radium persist for thousands of years. It is clear, then, that
* In addition, a Nuclear Regulatory Commission Branch
Technical Position(33) presents options for storage of
thorium and uranium waste from past operations. These are
often contaminated soils for which there may be little
practical alternative to on-site burial. The NRC reviews
and approves each licensee's waste disposal activities on a
case-by-case basis. For these and other reasons, the NRC
disposal options may not be appropriate for newly-generated
drinking water treatment wastes.
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even doubling the radium level in soil may have serious health
risk implications, especially if the increase occurs over a large
area.(
Separate from the risk attributable to inhalation of radon
and its decay products, radium-226 in soil at 1 pCi/g can lead to
an estimated lifetime risk level of approximately 2 x 10 " from
direct, external radiation exposure (assuming continuous lifetire
exposure one meter above an infinite plane of soil contaminated
at this level). The other major naturally occurring
radionuclides that may be concentrated by drinking water
treatment plants, uranium and lead-210, do not have radon
associated with them and external exposures are significantly
less. However, lead-210 represents the greatest risk from
ingestion (among the isotopes in the uranium decay chain) and
thus should be controlled at concentrations approximating radium
concentrations. Suggested guidelines for radium may also be
applied to the radon progeny lead-210. Lifetime cancer risks
from background levels, at 1 pCi/g, of U-238 and decay products
are shown in Table 3.
Risks attributable to exposure to radium-228 are similar
in magnitude to those of radium-226. Although radium-223 has-a
relatively short half-life (about 6.7 years), continued
deposition of this isotope may result in long lasting potential
exposures and resultant risks. Therefore, all of the following
discussion concerning radium levels in soil, in wastes, and in
landfilled materials, implies combined radium, i.e., radium-226
and radium-228, and applies to lead-210. as mentioned previously.
Table 3. Risks From Ingestion and External Radiation From
Background Values of U-238 and Decay Products
LIFETIME CANCER RISK
U-238/U-234b Th-230 Ra-226c Pb-210 Po-210
Ingestion* 3xlO'6 IxlO"8 9xlO"7 3xlO"5 3xlO"6
External
Radiation" 3xlO'6 9xlO"8 2xlO"4 3xlO"7 9xlO'10
a Value of all radionuclides are assumed to be 1 pCi/g in soil.
b Includes Th-234, Pa-2341", and Pa-234.
c Includes Rn-222, Pb-214, Bi-214, and Po-214.
d Ingestion factors are from reference 36; it is assumed an
individual obtains his/her total intake of vegetables, meat,
and milk from land contaminated at these levels.
e External radiation estimates are from information provided in
references 37 and 38. 70% dwelling occupancy and 30% shielding
(by dwelling) were assumed for external radiation values.
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Based on the above discussion, the main principles that EPA
has used in determining the safe disposal of naturally occurring
-solid radioactive waste are:
1. Since average soil concentrations for radium already
correspond to a relatively high lifetime risk, average soil
concentrations should not be allowed to increase by more than a
small amount.
2. When higher concentration radium wastes are disposed of,
they should be stabilized in a manner comparable to disposal of
uranium mill tailings to prevent migration and human intrusion so
that risks from direct exposure and ingestion will be minimized.
3. Since there is no radon risk directly associated with
uranium and the risk from direct exposure to uranium is about one
and one-half orders of magnitude less than that from radium, and
about 10 times less than that from lead-210 (Table 3),
concentration limits for uranium could be set about 10 times
higher than for radium and lead-210.
1. Solid Wastes Containing up to 3 pCi/g Radium
Because of the high inherent radon risks posed by normal
radium levels, even "near background" wastes should not be
disposed of indiscriminately.
Wastes containing less than 3 pCi/g (dry wgt) radium may be
placed in a municipal landfill. Wastes should be dewatered prior
to emplacement to avoid migration of contaminants. Sludges should
be spread and mixed with other materials when emp.laced, and when
combined with other radioactive materials placed in the landfill,
should total only a small fraction of the material in the
landfill. This procedure should provide adequate assurance that
any future indoor radon hazard from the material will be minimal,
and would minimize exposure to landfill workers.
EPA does not recommend the application, mixing or otherwise
spreading of water treatment wastes containing naturally
occurring radionuclides onto open land (i.e., farm land, pasture,
orchard or forestry lands, construction sites, roadbeds, etc.).
There are several reasons for this, among them:
1. Data relating to plant, animal, and human uptake, and
potential exposure that may result from land-applied water
treatment wastes containing naturally occurring radionuclides
need to be collected and analysed.
2. The long-term control of and monitoring at a site that
may contain higher than background levels of radionuclides (which
in some cases are very long-lived) cannot be assured.,
3. Diluting of wastes runs counter to EPA's general policy
of concentrating wastes prior to safe disposal.
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4. EPA has not collected or reviewed any data in regard to
the status of surface runoff from sites which host land
application of water treatment wastes.
5. Although certain types of sludges have been found to
have beneficial properties as amendments to agricultural soils,
EPA has not determined that the beneficial results outweigh
potential adverse results such as food-chain contamination,
future misuse of sites for building, and impacts on surface and
groundwater quality.
2. Medium Concentration Radium-bearing Solid Wastes
Disposal of water treatment waste containing radium concen-
trations from 3 pCi/g to about 50 pCi/g should provide reasonable
assurance that people will be protected from radon releases from
the undisturbed waste and that the waste will be isolated to
reduce the risk of disturbance or misuse. At these concentration
levels, the radon risk associated with any building that may be
built on a disposal site containing radium-226 and prolonged
exposure to direct gamma radiation from the material becomes a
concern. Construction directly on the waste or its use in
residential or commercial construction is not appropriate.
Sludges should be dewatered prior to disposal to minimize
migration after emplacement. Furthermore, properly designed
physical barriers are necessary to ensure compliance with the
goals of reducing releases of radiation and inhibiting misuse.
Supplementing such barriers with institutional controls designed
to avoid long-term inappropriate'uses of the site is also
appropriate, but, consistent with EPA policy, such institutional
controls should not be relied on for any assurance of protection
for more than one hundred years.
While the specific measures needed to achieve these goals at
specific sites will vary with the characteristics of the site, a
physical barrier of ten feet of cover of earth or non-radioactive
waste, if properly designed for long-term stability of the waste
and the cover if left undisturbed, should usually suffice to
achieve these objectives.
Full compliance with 40 CFR Part 257 and 258 regulations as
may be promulgated for landfills is in order. The degree of
additional protection a jurisdiction wants, to provide against
intrusion and misuse, may vary with site location, but should be
determined prior to waste disposal. A jurisdiction, for example,
may choose to provide for groundwater protection by specifying
RCRA hazardous waste requirements, such as properly engineered
liners, to prevent seepage of contaminants out of the landfill.
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3. Radium-bearing Solid Wastes With Concentrations Between
50 and 2.000 pCi/q (dry)
Individual situations should be assessed carefully and
disposal options evaluated thoroughly when concentrations exceed
50 pCi/g. Worker safety in waste handling becomes a more sig-
nificant concern. As the radium concentration increases, some of
the assumptions made above become questionable. One needs a
higher degree of assurance that intruders will not be endangered,
ground water and ambient air pathways are adequately controlled,
and the site is adequately secure against natural disturbances,
such as floods. More effective institutional controls against
future misuse of the site are needed than are generally available
for sanitary landfills. Disposal in conformance to the standards
specified for uranium mill tailings at 40 CFR 192(35) should be
considered. A decision not to fully employ such methods should
be based on a demonstration of significant differences between
the quantity and potential for migration of uranium mill tailings
versus water treatment wastes. EPA recommends that water
treatment wastes with radium concentrations exceeding 50 pCi/g be
subject to such individual consideration by appropriate State and
local authorities. At a minimum, disposal in RCRA permitted
hazardous waste units should be considered.
As mentioned above, some States may have NARM disposal sites
which may accept radium-bearing solid wastes in this, or other,
concentration ranges. Sites meeting those criteria should be
considered as the option of choice for wastes containing
radionuclides at this level.
At concentrations approaching 2,000 pCi/g, disposal of
wastes at licensed low-level radioactive waste disposal
facilities should be considered.
Wastes in this category should not be diluted for disposal
by less protective methods. Because of the great waste volume
expansion that this could entail, and the difficulties of
isolating the material from people, disposal methods which may be
useful for low concentration wastes may provide inferior
protection. Furthermore, variations in raw water quality,
treatment performance, or sludge dewatering could elevate
radionuclide levels well beyond planned margins of safety.
4. Wastes Containing More Than 2.000 pCi/q (dry weight) of
Naturally Occurring Radioactivity
Based on draft EPA standards for low-level wastes, drinking
water treatment wastes containing more than 2,000 pCi/g of
naturally-occurring radioactivity should be disposed of in a low-
level radioactive waste disposal facility that is regulated
under the provisions of the Atomic Energy Act or in a facility
that is permitted by EPA or a State to dispose of discrete NARM.
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C. Disposal Rationale for Uranium Contaminated Sludges/Wastes*
The risk from disposal of uranium contaminated solid
wastes on land stems primarily from external gamma radiation and
ingestion of foodstuffs grown or meat and milk from animals
grazing on such land. Risks from background concentrations at 1
pCi/g of radionuclides in the uranium decay chain are summarized
in Table 3 above. In addition to the risks shown in the table,
Ra-226 poses a potential inhalation hazard from indoor radon as
described previously. The risk from radium-226 and its short-
lived decay products dominates the total risk from the uranium
chain. Thus, it is important to establish what the level of
radium-226 and lead-210 is in sludge before applying guidelines
for disposal of sludge contaminated with uranium. Materials
should be disposed of under the most stringent of the applicable
guidelines.
Considering the long-term radiation risk from external
exposure or ingestion of uranium, and assuming there is little
radium-226 present, there are three general approaches to
disposal of uranium bearing solid wastes from water treatment,
if:
' * the concentration is sufficiently low, as defined in the f
following paragraphs, the waste may be placed in municipal
landfills in a manner that affords adequate protection
without institutional controls,
* the wastes may be stabilized so as to provide long-term
isolation against natural migration processes and human
intrusion, or
• the concentration is sufficiently high, uranium wastes may
be processed (i.e., "recovered") for their uranium values.
The same control concepts apply for uranium as for radium
although the concentration levels are increased by a factor of
10. This is due to the lower risk levels associated with uranium,
as compared to radium (Table 3).
Different concentrations of wastes can be disposed of under
these general approaches in a manner that assures public health
and environmental protection as follows:
1. Solid Wastes Containing up to 30 pCi/g (dry weight)
Uranium^
Low concentration uranium contaminated wastes may be
disposed of in a municipal landfill so as to pose essentially no
initial hazard and to minimize the likelihood of hazards from
future use. Solid wastes should be placed so as to assure
dilution in earth if any future activity is ever conducted.
* These guidelines do not address chemical toxicity of uranium.
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2. Solid Wastes Containing 30 to 2.000 pCi/cr (dry weight1
Uranium
The disposal method for solid wastes containing 30 to 2,000
pCi/g of uranium should be determined case-by-case. In general, .
it appears that disposal in a controlled landfill environment,
possibly after waste pretreatment, would assure dilution and
shielding to control external radiation. However, such disposal
should be examined to ensure that sludges, in combination with
other radioactive materials, do not constitute a substantial
fraction (greater than about 10% of the volume) of the total
wastes in the landfill.
For solid wastes in the high end of this range, such as at
concentrations greater than 500 pCi/g, more effective physical
stability and groundwater protection controls and institutional
controls against misuse may be needed. Disposal of wastes in
this range may require such controls as provided by EPA in
standards for uranium mill tailings. Hazardous waste disposal
requirements should be considered.
The Nuclear Regulatory Commission has not specifically •
addressed the licensing of source material (waste containing, by
weight, 0.05% or more uranium) concentrated by water treatment j
works. However, the provisions in 10 CFR Part 40 could be used •
to license, or to exempt from licensing, the source material if
the 0.05% weight concentration is exceeded.
As mentioned above, some States may have licensed HARM
disposal sites which accept radionuclide wastes in this concen-
tration range or at activities greater than 2,000 pCi/g.
3. Solid Wastes Containing More Than 2.000 pCi/q of Uranium
Guided by EPA's draft standards for low-level radioactive
waste, solid wastes with uranium and other natural radioactivity
at concentrations exceeding 2,000 pCi/g should be disposed of in
a low-level radioactive waste disposal facility operated under
the provisions of the Atomic Energy Act or at a facility that is
permitted by EPA or a State to dispose of discrete NARM.
Alternatively, uranium at these concentrations can be considered
a resource, as discussed above.
NRC provisions may be applied for wastes containing more
than 0.05% uranium, by weight.
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D. Disposal Guidelines
The following guidelines apply to the disposal of radio-
active solid wastes from the treatment of drinking water. The
guidelines address only naturally occurring radioactivity, and do
not account for potentially hazardous nonradioactive
constituents of such wastes. Wastes containing mixtures cf
radionuclides should be disposed of under the most stringent
applicable guideline. The concentration of each radionuclide as
well as the combined level of radioactivity in waste residuals
need to be considered. For example, the responsible entity may
wish to use formulae which compute and sum up fractional levels
of each radionuclide, as suggested in the above sanitary sewer
disposal guidance. These guidelines notwithstanding, solid
wastes from drinking water treatment processes should also be
disposed in compliance with EPA and State landfill criteria in 40
CFR 257 and 258, as applicable. All stated concentrations refer
to dry material.
1. Solid Wastes Containing Less Than 3 pCi/g (dry) of
Radium and Lead-210. and Less Than 30 pCi/g (dry) of
Uranium
<
Wastes containing less than 3 pCi/g of radium and lead-210
and less than 30 pCi/g of uranium may be disposed of without the
need for long-term institutional controls in a municipal landfill
if the wastes are first dewatered and then spread and mixed with
other materials when emplaced. The total contribution of
radioac-tive wastes to the landfill should constitute only a small
fraction (less than about 10% of the volume) of the material in
the landfill.
2. Solid Wastes Containing 3 to 50 pCi/q (dry) of Radium
and Lead 210
These wastes should be disposed of with a physical barrier
(i.e., a cover) that would protect against radon release and
isolate the wastes, and provided with institutional controls
designed to avoid inappropriate uses of the disposal site. A
physical barrier consisting of ten feet of cover of earth or non-
radioactive waste, properly designed for long-term stability of
the waste, should suffice.
Sludges should be dewatered prior to disposal to minimize
migration of contaminants. Consideration should be given to the
hydrogeology of the site and other factors affecting long-term
stability of the wastes. Sites that fully comply with EPA's
Subtitle D regulations and guidance under the Resource Conser-
vation and Recovery Act would be adequate disposal sites.
A jurisdiction may choose to ensure groundwater protection
by specifying RCRA hazardous waste requirements, such as properly
lined waste units, or sludge stabilization, to prevent seepage of
contaminants out of the landfill. The degree of additional
protection a jurisdiction wants to provide against intrusion and
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-30-
misuse may vary from site to site, but should be determined prior
to waste disposal.
3. Solid Wastes Containing 50 to 2.000 pCi/g (dryj
of Radium and Lead-210
The disposal method should be determined case-by-case.
Methods that comply with EPA's standards for disposal of uranium
mill tailings should be considered (40 CFR 192). A decision not
to fully employ such methods should be based on a demonstration
of significant differences between the quantity and potential for
migration of uranium mill tailings versus water treatment wastes.
The disposal method should be augmented by long-term
institutional controls to avoid future misuse of disposal sites.
Such institutional controls are not normally already in place at
sanitary landfills. At a minimum, disposal in RCRA permitted
hazardous waste units should be considered.
In States where HARM disposal is licensed or permitted,
disposal at a NARM site should be considered for radium or lead-
210 bearing solid wastes.
• At concentrations approaching 2000 pCi/g, disposal of waste*
within a licensed low-level radioactive waste disposal facility,t
or a facility that is permitted by EPA or a State to dispose of '
discrete NARM, should be considered.
4. Solid Wastes Containing 30 to 2.000 pCi/q (dry weight)
Uranium
(a) The disposal method should be determined case-by-case.
At the low concentration end of this range, such as 30 to 500
pCi/g uranium, disposal at municipal landfill may be considered,
provided that a physical barrier isolates the wastes and
institutional controls are designed to avoid inappropriate usage
of the site; the radioactive solid wastes make up no more than
10% of the total waste volume in a landfill; and ground water
will be adequately protected. At the high concentration end of
this range, such as at concentrations greater than 500 pCi/g,
disposal methods approved for hazardous wastes or uranium mill
tailings should be employed, especially for large waste
quantities. Also, at concentrations approaching 2000 pCi/g,
disposal of wastes within a licensed low-level radioactive waste
disposal facility should be considered.
(b) In States where NARM disposal is licensed or permitted,
that option should be considered for uranium bearing solid
wastes.
(c) Recovery of the uranium resource (i.e., at uranium
milling site) should be considered for wastes containing greater
than 0.05% (by weight) of uranium. NRC may license material at
this uranium concentration (greater than 0.05%) as a "source
material" under the provisions of the Atomic Energy Act.
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5. Solid Wastes Containing More Than 2.000 pCi/g (dry) of
Natural Radioactivity
Wastes with natural radioactivity concentrations exceeding
2,000 pCi/g should be disposed of in a low-level radioactive
waste disposal facility operated under the provisions of the
Atomic Energy Act, as amended, or at a facility that is permitted
by EPA or a State to dispose of discrete NARM.
6. Recordkeeping
It is suggested that water treatment facilities keep records
of the amount and composition of radioactive wastes (solid and
liquid) they generate and of the manner and location of their
disposal. Repositories of wastes containing more than 50 pCi/g
(dry weight) should be permanently marked to ensure long-term
protection against future misuse of the site and/or its
materials. However, this guideline is not meant to cause an
increase in Federal record keeping requirements for water
treatment facilities.
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Figure 2
Guideline Summary For Water Treatment Plant Solid Wastes
Containing Natural Radioactivity
| WTP SOLID WASTES |
[initial screening)
Ra <3 pCi/g
ft>-210 <3
U <30
1
i
Dewatered sludges
to landfill —
spread and mixed*
Ra
ft>-210
U
1
3 to 50
3 to 50
30 to 500
pCi/g
Ra 50 to 2000 pCi/g
ft>-210 50 to 2000
U 500 to 2000
1
>2000 pCi/g
natural
radioactivity
JL
1
Case-by-case
Determination.
May dispose of as
uranium mill tail-
ings (40 CFR 192)
or as hazardous
wastes
NARM disposal I
where appropriate!
Stabilized landfill with
10 ft. earth cover or
other physical barriers;
long-term site control*
If U >0.05%, waste is
regulated as "source mat-
er ial"(10CFR40); Uranium
Recovery option available
i
LO
NJ
I
Disposal at low level
radioactive waste
facility or a State or
EPA permitted facility
* Land disposal requirements may apply: 40 CFR 257, 258 and 260=266, which are RCRA requiranents.
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Recommended Radiation Exposure Guidance for Workers
In Water Treatment Facilities
In determining appropriate radiation exposure limits for
water treatment plant workers, there are a number of pertinent
sources of guidance which can be used as a basis for reconnenda-
tions. In general, individuals in the United States receive an
average radiation dose of approximately 360 millirems per year
(mrem/yr) from all sources including radon <40). The
International Commission on Radiological Protection (ICRP)
recommends that additional man-made exposure of members of the
general public due to chronic exposure from all sources excluding
medical exposure and background be limited to 100 mrem/yr, and^
that no single source provide a large fraction of this limit (""'.
As this document provides recommendations for workers, it is
appropriate to cite the "Radiation Protection Guidance to Federal
Agencies for Occupational Exposure," approved by the President in
January of 1987 (4 . That guidance limits doses to workers to an
upper bound of 5,000 mrem/year and further recommends that (a)
doses be as low as reasonably achievable (ALARA), under this
limit, and (b) doses not approach the limit for substantial
portions of a working lifetime. Under the recommendations of thfe
Radiation Protection Guidance, occupational exposure limits which
take into account ALARA may be developed below the limiting
values for specific categories of workers or work situations.
Personnel in water treatment facilities removing naturally
occurring radionuclides from drinking water may be exposed to
higher-than-background radiation levels. The doses that these
workers would receive, however, as discussed in the next section,
are normally very much lower than the upper bounds for workers in
radiation facilities. As there is no need to allow these workers
to receive radiation exposures up to the occupational limits, and
since radiation exposures should be maintained as low as
reasonably achievable, it is appropriate and feasible to limit
these workers to exposure limits much less than 5,000 mrem/yr.
Based on the radiation levels that treatment plant workers
may be exposed to and taking into account the recommendations of
the Radiation Protection Guidance for occupational exposure of
workers, it appears a reasonable objective to keep treatment
plant workers' exposures to well within the levels recommended
for the general public (i.e., 100 mrem/yr) with respect to man-
made sources of radiation. An occupational exposure level of 25
mrem/yr for external and committed effective dose equivalent
would meet these objectives and is reasonably achievable at water
treatment plants.
Gamma survey instruments are usually available from State or
local county health agencies for the purpose of making
measurements to determine direct radiation dose rates at water
facilities which remove radioactivity.
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-34-
Workers who will be exposed to significant levels of
exposure above background should receive proper training and have
their exposures monitored. For protection of workers, it is
necessary to identify areas within the treatment plant where the
suggested limit of 25 mrem/yr may be exceeded. Based on these
requirements, it is suggested that radiation measurements be made
within the plant and that areas which have external radiation
levels which could lead to worker exposures equal to or greater
than the limit of 25 mrem/yr be identified and posted with signs
reading "Caution Radiation." Individuals working in the
designated areas for a significant period of time should have
their exposures assessed and receive general radiation protection
training.
In addition to direct radiation exposures, water treatment
plant workers can be exposed, through inhalation, to harmful
radon gas. Radon screening indoors may be performed easily and
inexpensively by use of simple, commercially-available radon
detectors. EPA recommends to homeowners that they take some
action to permanently reduce radon levels in their homes as much
as reasonably achievable (43>. Based on the ease of achieving low.
levels for drinking water treatment plant workers, it is
recommended that action be taken to reduce airborne radon levels1
in water treatment facilities as much as possible. Because of the
different conditions in work places, the times over which radon
in air concentration is measured and averaged may be less than
one year if appropriate (chosen to correspond to normal working
hours and conditions).
Sources of Radiation in Water Treatment Plants
Water treatment plant operators may be exposed to radiation
other than background near the vicinity of media vessels
containing ion exchange resins, granular activated carbon, and
sand filter beds. All of these media concentrate the radioactive
contaminants to be removed from the water. Additional sources of
radiation include radon gas from stripping towers and aerator/
reservoir basins.
Studies by Bennett concluded that radiation exposure to
operators at water treatment plants which remove radium would not
typically exceed 25 to 100 mrem/yr above background levels.
A study conducted by EPA at the Elgin, Illinois water treatment
plant found significantly higher radiation levels near the sand '
surface of one pressure filter bed that was drained for service.
However, the study concluded that because no worker would be
exposed for any great length of time, such a situation would not
pose an unacceptable hazard. Another study performed by the
State of Wisconsin at a water treatment plant in Elkhorn,
Wisconsin, indicated that gamma radiation exposure levels near
the ion exchange vessels were barely detectable over background
levels. Measurements at the surfaces of settling tanks, along
the bottom and top of the aerator/reservoir, along the sides of
iron filters, and within the general plant area indicated that
gamma radiation was not detectable over background levels.
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Radiation levels higher than background may be encountered
in facilities that utilize exchange or adsorption media that have
a strong affinity to the contaminant to be removed. Anion
exchange resins removing uranium, selective sorbents removing
radium, and granular activated carbon (GAC) used to remove radon
have the capability of accumulating relatively high levels of
radionuclides during their service life. Radiation measurements
have detected gamma radiation levels 2 to 5 times above
background levels in the vicinity of GAC systems removing radon
from drinking water (28). One recent study indicated that
measured gamma radiation at the surface of GAC water treatment
units, with influent radon at approximately 190,000 pCi/1, which
is a very high level, ranged from 1.8 to 16 mrem/hr (bottom and
top of units, respectively)(45>. Another report indicates that an
empirical relationship of 1.0 mrem/hr (maximum gamma on the GAC
vessel) per 10,360 pCi/1 of influent radon was observed, based on
measurements at 10 sites<46). It is noted, however, that gamma
radiation from a GAC unit treating for radon is significantly
reduced within a few feet of the unit.
Personnel removing media from filter beds, ion exchange
vessels, or handling sludges may be exposed to radiation above
background levels during the time the tasks are being performed.
In addition to external exposures to radiation, radon gas within'
the water treatment facility can be a source of internal exposure
to the lungs. Radon gas can build up to high concentrations in
poorly ventilated areas, although proper ventilation should
reduce levels to near background.
Water treatment facilities should generally set work
practices and monitoring as prerequisites of a"n effective ALARA
program. Control of internal exposure may be needed depending on
waste form and activity and employee work practices.
Exposure Guidelines
1. Routine Plant Operations
a. General radiation levels in areas of water treatment
plants removing radionuclides from drinking water should be
monitored at least yearly, using gamma survey instruments or
equivalent monitors.
b. Radiation levels in the vicinity of components
concentrating radioactive materials should be monitored at least
quarterly.
c. Additional measurements should be performed if the
component accumulating the radionuclide is replaced, if the
process is changed, if the length of service is increased, or if
significant increases of radionuclide concentration levels are
experienced in the influent water.
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d. Radiation exposure to personnel working in a drinking
water treatment facility should not exceed 25 mrem/year, and be
kept as far below this level as reasonably achievable.
e. If areas in a treatment plant are identified where an
individual working in the area could receive a short-term
exposure that would be a significant fraction of the above limit,
such as 1 mrem/day, those locations should be boldly marked
"Caution Radiation" and restricted to specified personnel.
f. Persons working in areas marked "Caution Radiation"
should have appropriate radiation protection training and their
radiation exposure monitored through area monitoring or personnel
monitoring, as appropriate.
g. Radon levels in the air should be monitored and action
should be taken, where appropriate, to reduce radon levels in air
as much as possible. Because of short-term conditions that may
result in elevated exposures, such as during maintenance of
treatment units, the time period over which the radon
concentrations are averaged may be chosen to correspond to normal
working hours and conditions. Improved ventilation should be
considered for the reduction of airborne radon.
h. Sludge storage sites, evaporation and drying lagoons
should be fenced to prevent unauthorized intrusion.
2. Handling and Shipping Radioactive Wastes for Disposal
a. When removing and preparing wastes containing
radionuclides for transportation and disposal, the task should be
evaluated to keep radiation exposures as low as reasonably
achievable. This may entail special training, tools, or
shielding. In addition, personal protective equipment, such as
respirators and protective clothing, may be necessary to reduce
exposures in some situations.
b. Granular activated carbon beds used to remove radon from
water should be taken out of service and allowed to stand at
least three weeks before the beds are replaced. This will allow
time for decay of radon and short-lived daughter products. This
precaution will reduce radiation exposure to the personnel
handling the discarded GAC. If system constraints do not allow
the unit to be removed from service for three weeks, alternative
means should be used to reduce exposures from radon and its
daughter products.
c. Only properly trained personnel should handle
radioactive wastes.
d. Personnel handling radioactive wastes should have their
radiation exposure monitored.
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e. Total radiation exposure to personnel working within
water treatment plants, including handling the wastes, should not
exceed 25 mrem/yr and should remain as low as reasonably
achievable.
f. When handling and shipping radioactive wastes, the
appropriate local, State and OSHA regulations should be followed.
g. When shipping radioactive materials whose concen-
trations exceed 2,000 pCi/g, the appropriate Department of
Transportation standards must be followed as prescribed in 49 CFR
Parts 100 - 179.
h. Wastes containing uranium in excess of 0.05% by weight
are considered source materials as defined in 10 CFR Part 40.
Water treatment facilities producing, handling, disposing of and
transporting wastes containing uranium in excess of 0.05% by
weight would have to obtain a license from the U.S. Nuclear
Regulatory Commission, unless conditions defined in 10 CFR 40
("Domestic Licensing of Source Material") are met which exempt or
preclude licensure.
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References
1 National Interim Primary Drinking Water Regulations.
Federal Register. 45(168):573257.
2 Management of Water treatment Sludge Containing Elevated
Levels of Radium. Illinois Department of Nuclear Safety.
December, 1984.
3 Interim Guidelines for the Disposal of Liquid and Solid
Wastes Containing Radium for Wisconsin Water Treatment
Plants. Wisconsin Department of Natural resources, October,
1985.
4 Suggested State Regulations for Control of Radiation.
Conference of Radiation Control Directors, 1982.
5 New Hampshire Rules for the Control of Radiation. State of
New Hampshire, state Department of Health and Welfare,
Concord, NH., April, 1983.
6 Rules and Regulations Pertaining to Radiation Control.
Colorado Department of Health, 1978.
7 R.J. Schliekelman, Determination of Radium Removal
Efficiencies in Iowa Water Supply Treatment Processes,
Technical Note ORP/TAD76-1, EPA. June, 1976.
8 Brinck, W.L. et.al, Radium Removal Efficiencies in Water
Treatment Processes. JAWWA 70(l):31-35, 1978.
9 Manual of Treatment Techniques for Meeting the Interim
Primary Drinking Water Regulations, EPA-600/8-77-005 May,
1977.
10 Lassovszky, P. and Hathaway, S., Treatment Technologies to
Remove Radionuclides from Drinking Water. Preconference
Report for the National Workshop on Radioactivity in
Drinking Water, Easton, Maryland, May 24-28, 1983, U.S. EPA,
Washington, D.C.
11 Ciccone, V.J. and Associates, Technologies and Costs for
the Removal of Radium from Potable Water Supplies. Report
Prepared for the U.S. Environmental Protection Agency, V.J.
Ciccone and Associates, Woodbridge, VA. August, 1983.
12 Bondietti, et.al. Methods of Removing Uranium from Drinking
Water: II Present Municipal Treatment and Potential
Treatment Methods. EPA-570/9-82-003, ORNL/EIS-194.
December, 1982.
13 Hanson, S.W., Wilson, D.B., Gunaji, N.N., Removal of
Uranium from Drinking Water by Ion Exchange and Chemical
Clarification. EPA/600/S2-87/076, Cincinnati, OH. December
1987.
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-39-
14 Ciccone, V.J. and Associates, Technologies and Costs for
the Removal of Uranium from Potable Water Supplies. Report
Prepared for the U.S. Environmental Protection Agency, V.J.
Ciccone and Associates, Woodbridge, VA. October, 1985.
15 Sorg, T.J., Removal of Radium-226 from Drinking Water by
Reverse Osmosis in Sarasota County, Florida, JAWWA, April,
1980.
16 Lauch, R.P. Removal of Radium from Drinking Water, a
Research Summary. U.S. Environmental Protection Agency,
Water Engineering Research Laboratory, Cincinnati, Ohio.
17 Shelley, W.J., Removal of Radium from Water by Direct
Precipitation by a Soluble Barium Compound. Kerr-McGee
Corporation. Letter to George Reed, Director, Bureau of
Water Resources, University of Oklahoma, April 1983.
18 Evaluation of Barium-Radium Coprecipitation as a Treatment
Process for a Domestic Water Supply for Midland, South
Dakota. A report prepared for the Bord of Trustees, Town of*
Midland. Banner Associates, Inc., January 1981.
19 Lowry, J.D. and Brandow, J.E. Removal of Radon from Water
Supplies. Journal of Environmental Engineering, Vol. Ill,
No. 4, August, 1985.
20 Technologies and Costs for the Removal of Radon from Potable
Water Supplies. Report Prepared for EPA by Malcolm Pirnie,
Inc., Paramus, NJ. January, 1987.
21 Rozelle, R.E. et. al. Potable Water Radium Removal Update on
Tests in Missouri, Iowa, and Wyoming by the Dow Company.
Internal Report, Dow Chemical Company, Midland, Michigan.
22 Clifford, D. et al. Evaluating Various Adsorbents and
Membranes for Removing Radium from Groundwater. JAWWA,
July, 1988.
23 Snoeynk, V.L. et. al. Removal of Barium and Radium from
Groundvater. Environmental Research Brief. EPA/600/M-
86/021. February, 1987.
24 Determination of Radium Removal Efficiencies in Illinois
Water Supply Treatment Processes. U.S. EPA Technical Note
ORP/TAD-76-2. June, 1976.
25 Ciccone, V.J. and Assoc. Analysis of Occurrence, Control
and/or Removal of Radionuclides in Small Drinking Water
Systems in Virginia. Report prepared for the U.S. EPA,
Office of Drinking Water. Woodbridge, VA. September, 1987.
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-40-
26 Disposal of Radium-Barium Sulfate Sludge from a Water
Treatment Plant in Midland, South Dakota. A technical
assistance program report prepared for the U.S.
Environmental Agency, Region VIII, Denver, Colorado, Fred C.-
Hart Associates Inc., December, 1982.
27 Radon Removed from Water Using Granular Activated Carbon
Absorbtion. Maine Department of Human Services, Division of
Health Engineering, September, 1986.
28 Memorandum from Thomas Sorg, EPA, WERL.
29 Ore Mining and Dressing Point Source Category Effluent
Limitations Guidelines and New Source Performance Standards,
40 CFR Part 440 [WH-FRL 2232-1]. Federal Register Vol. 47,
No. 233, 54598, December 3, 1982.
30 Standards for Protection Against Radiation, 10 CFR Part 20.
Federal Register, January 31, 1985."
31 National Council of Radiation Protection, Report #94,
December 30, 1987.
32 Uranium Mill Tailings Standards. 40 CFR 192.
33 U.S. Nuclear Regulatory Commission, Disposal or Onsite
Storage of Thorium or Uranium Wastes from Past Operations,
46 FR 52061, October 23, 1981.
34 U.S. Environmental Protection Agency, Advance Notice of
Proposed Rulemaking, Environmental Radiation Protection
Standards for Low-Level Radioactive Waste Disposal, 48 FR
39563, August 31, 1983.
35 Final Environmental Impact Statement for Remedial Action
Standards for Inactive Uranium Processing Sites (40 CFR
192), Chapters 3 and 4, Environmental Protection Agency
520/4-82-013-1, October 1982; and Health Physics, Vol. 45,
No. 2, August, 1983.
36 U.S. Environmental Protection Agency, Environmental Impact
Statement — NESHAPS for Radionuclides, Vol. 1. EPA/520/1-
89-005, September 1989.
37 National Council on Radiation Protection and Measurements:
National Background Radiation in the United States. NCRP
Report No. 45, Nov. 1975.
38 Kocher, D.C., Dose Rate Conversion Factors for External
Exposure to Photon and Electron Radiation from Radionuclides
Occurring in Routine Release from Nuclear Fuel Cycle
Facilities. Health Physics Vol. 38, No. 4. April, 1980.
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39 National Emission Standards for Hazardous Air Pollutants;
Standards for Radionuclides, 40 CFR Part 61 [AD-FRL-2764-
7]. Federal Register. Vol. 50, No. 25, February 6, 1985.
40 National Council for Radiation Protection and Measurements.
Report #93. September 1, 1987.
41 Recommendations of the International Commission on Radiation
Protection, ICRP Publication 26. January, 1977.
42 U.S. Environmental Protection Agency, Radiation Protection
Guidance to Federal Agencies for Occupational Exposure:
Recommendations Approved by the President. Washington, D.C.
1987.
43 Health and Human Services, "A Citizens Guide to Radon: What
It Is and What to Do About It", OPA-86-004, U.S. Government
Printing Office, Washington, D.C. August, 1986.
44 Bennett, D.L. The Efficiency of Water Treatment Processes
in Radium Removal. JAWWA. December, 1978.
45 Kinner, N.E. et al. Radon Removal From Drinking Water Usinp
Granular Activated Carbon, Packed Tower Aeration and
Diffused Bubble Aeration Techniques. Presented at 1988 •
Symposium on Radon and Radon Reduction Technology, Denver,
CO. October 17-21, 1988.
46 Lowry, J.D. et al. New Developments and Considerations for
Radon Removal From Water Supplies. Presented at 1988
Symposium on Radon and Radon Reduction Technology, Denver,
CO. October 17-21, 1988.
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GLOSSARY
Alpha radiation - A helium nucleus, two protons and two neutrons
emitted from the nucleus.
Beta radiation - An electron emitted from the nucleus as a
result of neutron decay.
Curie (Ci) - The activity of one gram of radium, or 3.7 x 1010
disintegrations per second.
Daughter - The isotope resulting from radioactive decay.
Dose - Quantity of radiation absorbed, per unit mass, by the body
or by any portion of the body.
Gamma radiation - A form of electromagnetic radiation. Gamma
decay will not result in a formation of a new isotope.
GAG - granular activated carbon: a medium useful in treatment of
water for the removal (sorption) of some contaminants, including
radon and many organic substances.
Half-life - The time required for one half of the atoms to decay*
Isotope - Varieties of the same element with different masses.
Ionizing radiation - Radiation that is capable of ionizing or
removing one or more electrons from an atom.
Licensed Material - Source material, special nuclear material, or
by-product material received, possessed, used or transferred
under a general or specific license issued by the U.S. Nuclear
Regulatory Commission.
Natural radioactive series - Sequence of elements that exist
naturally and decay in a serial fashion.
Parent - The isotope that undergoes radioactive (alpha or beta)
decay, resulting in a daughter product.
Picocurie fpCi) - One pCi equals 10"12 Curie.
Quality factor (Q) - A factor that roughly approximates the
relative differential damage that ionizing radiation can do to
tissue. For beta particles and all electromagnetic radiations
(gamma rays and x-rays), Q = 1. For neutrons from spontaneous
fission and protons, Q = 10. For alpha particles and fission
fragments, Q = 20.
- A measure of dose of any ionizing radiation to body tissues
in terms of the energy absorbed per unit mass of tissue. One radj
is the dose corresponding to the absorbtion
-------
-43-
Radioactive decay - A process where the nucleus transforms to a
lower energy state by emitting alpha, beta or gamma radiation.
Rem (Radiation Equivalent Man) - A measure of the dose of any
ionizing radiation to body tissues in terms of its estimated
biological effect. This term is more descriptive of the actual
damage done to tissues from ionizing radiation. The number of
rems is expressed in terms of a quality factor times the number
of rads. One Millirem fmrem) is one one-thousandth of a rem, or
10'3 rem.
Source material - Uranium or thorium in any combination thereof,
in any physical or chemical form or materials
that contain by weight 0.05% or -more uranium, or thorium
or any combination of these two substances.
Working Level(WL) and Working Level Month(WLM) - Any combination
of short-lived radon daughters (through Po-214) per liter of air
that will result in the emission of 1.3E+05 MeV of alpha energy.
An activity concentration of 100 picocuries per liter in air of
Rn-222 in equilibrium with its daughters corresponds approxi-
mately to one WL. A working level month(WLM) is an exposure to a
concentration of one WL for 170 hours (about 21 work days).
-------
-44-
APPENDIX
Estimated Radioactivity and Quantity of Water A-l
Treatment Waste Residues
Radium Concentrations in Lime Softening Wastes and A-2
Ion Exchange Wastes, 3 Tables
Results of Sarasota Co., Florida, A-3
Reverse Osmosis Radium-226 Removal Sampling
EPA Uranium Removal Field Study A-4
Radium Originating from Drinking Water A-5
in Wastewater Treatment Plant Sludges
Pb 210 Build-up in GAG Filter A-6
Farmland Application of Fertilizers A-7
Containing Natural and Accelerator
Produced Radioactive Materials
Sources of Radiation for People in A-8
the United States
Range of Nuclear Particles with the A-9
Same Energy
Natural Radioactive Decay Series A-10
Engineering Shorthand and Greek Prefixes A-13
Standards for Uranium Mill Tailings A-14
-------
eSTIMATB IAPIOACTIVITY AND QUANTITY OF WATER TREATMENT WASTE RESIDUES
Residue
Ltn*-Soda
Softening...
Sludge Ul
1. lew-Soda
Backwash Wster
Ion-Exchange
Regeneration
Brine
Reverse Osnoats
Reject Water
Ra«Us*ctlvlty Levels mm m Function of
Radioactivity of Raw Water. pCl/l
15
4,800-20.500
pCi/lbs Dry
Sludge
40-60
pCl/gal
490-2.460
pCl/gal
260-760
pCl/gal
10
6.900-34.100
pCi/lbs Dry
Sludge
130- 150
pCl/gsl
1.140-6.060
pCl/gal
450-1.020
pCl/g.l
50
10.500-51.400
pCl/lbs Dry
Sludge
245-265
pCl/gal
2.270-11.160
pCl/gal
750-1. H90
pel /gal
Quantity of
400
1.800- 1.200
Dry Ibs/MC
20.000-40.000
Gallona/HC
15.000 gal/HC
60.000 gal/NG
Waste Stream aa a Function of
TDS of Raw Water, ag/l
1.000
1.100- 6.500
Dry Ihs/MC
20.000- 40.000
Callona/HC
10,000 gal/HC
60.000-100.000
gal/Hti
2.000
7.600-16.200
Dry Iba/HC
20.000-40.000
Gal ions /HC
75.000 gal/NC
16 0.0 00-260.000
gal/NC
(I) Wet Ila« soda softening sludgea have been reported to contain between 2 to 15 percent aollda. After emended
of storage in a landfill or laipoundacnt. 70 percent aollda or greater have been reported. Valuea reported liere for
dry solids «ay be converted to values for wet sludge of different percent solids by Multiplying by Hie appropriate
conversion factor.
Source: EPA 600/2-77-071. Costs of Radius) Removal from Potable Water Supplies.
-------
A-2
SUKKARY OF RADIUM CONCENTRATIONS IN LIKE
SOFTENING SLUDGES AND BACKWASH WATERS
LOCATION *
u Oes *oines. IA
(raw water Ra-226
Lagoon Sludge
Clarifier Sludge*
lagoon Sludge
Backwash water
Clarifier Sludge
Colchester. IL
Clartfier Sludge
Backwash water
Webster City, IA
(raw water Ra-226
Sludge
Backwash Water •
Peru, It
(raw water Ra-226
Backwash water
etoin. ft
(raw water Ra-226
Active Lagoon Sludge
Inactive Lagoon Sludge
Clarifier Sludge
Backwash Water
Sludge"
Backwash Water
Sol ids
, 9.3
37.6
1.6
NA
NA
19
12.6
0.23
, 6.1
NA
HA
, 5.8
HA
, 5.6
57.3
67.1
10.3
0.051
HA
NA
,.226
(eCi/l)
pCi/1)
5,159
<20
2.300
6.3
4,577
2.038
<20
pCi/1)
980
50
pCi/1)
36.9
pCi/1)
9.642
11,686
948
<20
6.100
18.3
(PCi/l)
596
«40
HA
HA
<45
236
<39
HA
HA
HA
9.939
12,167
873
<40
HA
NA
DCi/a(dry)
10.8
<.02
NA
NA
21.6
15.0
NA
HA
HA
NA
11.3
10.9
8.6
<.02
-HA
HA
•a228
pCi/q(dry)
1.3
<.04
HA
NA
1.7
NA
NA
NA
NA
11.7
. 11.3
8.0
<.04
NA
NA
Assume specific gravity • 1.0
source Snoeyink, V. L. ,
et al..
"Characteristics
and Handling of
Wastes from Groundwater Treatment Systems," Sunday Seminar
on Experiences with Groundwater Contamination, AWWA National
Conference (1984).
-------
A-2a
Ra226 CONCENTRATIONS IN ION EXCHANGE.
TREATMENT PLANT WASTEWATER
Average
Average far Peak
Average Brine » Rinse 1/4 • 1/3 of
Brine » Rinse * Backwash Regeneration
Peak
Concentration Raw water
in Wastewater Concentration
LOCATION
Eldon, IA
Estherville, IA
Grmnell, I A
Holstem, IA
(oCi/l)
530
NA
110
175
(DCl/l)
420
52
NA
NA
Cvcle^ (oCi/t)
2,000
114
260
' 576
(oCi/l)
3,500
320
320
1,100
toe t / 1 )
46
5
6
13
source: schilekeiman : Determinacion of Radium Removal Efficiencies
in IlTinois Water Supply Treatment Processed.
EPA Technical Note, ORP/TAD-76-2 .(June 1976)j.
-------
A-2b
RADIUM CONCENTRATIONS IN
FILTER MEDIA AND SOFTENER RESINS
LOCATION FILTER/MEDIA CONCENTRATIONS MEASURED
TVTPE (pCi/q)
Herscher, IL*
Lynwood, IL**
Dwight Correct.
Iron Filter
Zeolite Softener
Zeolite Softener
Natural Greensand
Ra-226
111.6
43
9.6
28-46
Ra-228
33.9
15
6.6 -
59
Center, IL
*after 10 yrs. operation
**after 2 yrs. operation
Source: Bennett, D.L. The Efficiency of Water Treatment
Processes in Radium Removal. JAWWA (December 1978).
-------
A-3
PARTIAL RESULTS OF SARASOTA CO., FLORIDA, REVERSE OSMOSIS
RADIUM-226 REMOVAL SAMPLING!
System
Raw Water Raw Water Product Water Ra-226 Reject Percent System
TDS Ra-226 Ra-226 Removal Water Water Capacity
(mg/1) (pCi/1) (pCi/1) Efficiency Ra-226 Rejected (lOOOGPD;
_<*>_ (pci/i) (%)
Bay Lakes
Estates MHP
Venice
Sorrento Shores
Spanish Lakes
,MHP
Nokomis School
Bayfront TP
Kings Gate TP
Sarasota Bay
MHP
2,532
2,412
3,373
1,327
1,442
895
1,620
2,430
3.2
3.4
4.6
10.4
11.1
12.1
15.7
20.5
0.1
0.3
0.2
1.2
0.5
0.6
2.0
0.3
97
91
96
88
95
95
87
98
Average 93Z
40
t
7.8 46 * 1000
i
7.9 61 ' 200
20.5 69 70
11.9 - 0.8
19.4 72 1.6
30
37.9 50 5
TSorg, T.J., et al., JAWWA. April, 1980.
-------
A-4
EPA URANIUM REMOVAL FIELD STUDY'
(ANION EXCHANGE)
Unit
Location
Ft. Lupton, CO
Brighton, CO
Marshdale, CO
Cove, AZ
Church. Rock, NM
Raw Water
Uranium
(uq/1)
35.
23.
28.
64.
52.
Treated Water*
Uranium
(ug-/l)
35.
23.
<0.1
63.
0.1
Gallonst*
Treated
22,310t*
45,460t*
40,610
31,400t*
20,360
Bed
Capacity
(Ib Uranium/ft3)
0.007
0.009
0.017.
f
t
*
* Uranium concentration at indicated gallons treated
t* Test terminated at resin exhaustion
Capacity of bed not exhausted
Source: S.W. Hathaway and P. Lassovszky, 1982
-------
A-5
Radiun originating fron drirfcing water
in wastewater treatrvnt plant sludges
Location
Source
Sludge fro-. waste«ater plant
Fond du Lac Wise.
Ccmniry
v*ter supply
31.9 pCi/g dry wt
958 pCi/L 3% solids
Gross alpha 76.9 pCi/g
Gross beta 83.9 pCi/g
Digested Sludge
Juneau Wisconsin
Digested sludge
Lake Mills, Wisconsin
Backv*sh of- iron
flock firon DW
treacnent plant
Ccrrcmiry
water supply
70.9 pCi/g ery *.
692 pCi/L 3.3% solids
Gross alpha 119.6 pCi/g
Cress beta 96.8 pCi/g
31.9 pCi/g dry wt
1365 pCi/L 4.2% solids
Gross alpha 10°.8 pCi/g
Gross beta 79.8 pCi/g
Digested sludge
Colby, Wisconsin
Ion Exch. Regeneration
and back%*sh from DW
treatnent plant
38.5 pCi/g dry wt
1157 pCi/L 31 solids
Gross alpha 1H4.0 pCz/g
Gross beta IflR. 5 pCi/g
Concregation of
St Agrees, v&scemin
Ion Exch. Regeneration
and tadc%«sh frcn DW
treatment plant
24.9 - 38.5 pCi/g dry wt
750 - 1157 pCi/L 3% solids
Gross alpha 184.0-382.4 pCi/g
Gross beta 188.5-389.2 pCi/g
1 Williams, M. 1985. The Fate of Rad1um-226 and Rad1um-228 In the Wastewater
Treatment Process. A Survey. Wisconsin Department of Natural
Resources, Bureau of Solid Waste Management. August, 1985.
-------
50000i
40000
o 30000
o
I
o 20000
11
CVJ
.0
o.
10000
GIVEN 1000L/OPY
GRC 957. Eff.
Pb 0.057. of Rn
InfluL-nt Rn
Cone em rat Ion
300K pCi/L
ttONTHS
Lead 210 build-up in GflC Rn removal filter
Qnrn T 1 1 QRfl
-------
farmland Application of Fertilizers ("nntaininn Natural ami Accol oralor
Produced Kadioctd ive^l^rur ials (1)
Uaalr
Urd
4- II- 12
>-•-*
J-IO-1
grlcultoral
hoaph«a.ypau«>
Quantity generated
ftnutc* prr year
nur ILIra IIIOO H« Cl
r«-2IO
Po-JIO
ro-210
•a-22« *W 17
U-23M 1.2
Specific
activity.
pCl/|
14
1)
II
24
4.*
Cheat cat/
pliyalcal
fora. «C«A
Solid
$rlad
Monradlo-
loglcal Preeent
liaianla aeane of dlapoaal Coanente
Nona Applied to
farmland.
Mo«« Applied to Uncalclned phoephonypaua
faraiaod. for a|r {cultural purpoeea.
otauli
R-40
4070
<*,0
aioo
700 Solid
to
farvlaad.
duel Ida actlvllU* ara
baaed on calclntd photpho-
data.
fotaah application ««rlt«
with ooll cnaractcrlatlc*
and crop n««da.
•raft
rlpU
aaluai
•a-22t
11-2)1
TV no
IU-2J2
u-m
Tli-110
«a-m
1I.-2J2
U-211
lh-210
4JJ
•••0
0.2
24
22
10
O.t
m
3*1
41
21
21
20
20
0.4
4*
21
1.3
J8
37
4
3
Li^Hld
MOM
Hoao
I) Derived from "The Radiological Aspects of Fertilizer
Utilization. Richard J. Guimond. NURBG/CP-OOOl. August 1978.
FcrCllUar appt leal Ion
ran|a !• approilMltlr )»
•I C|0|/lirctaro fur barley,
wheat, and oat a and l>0 b|
PjOj/haetara far potataee.
Applied to ' The quant Ity of fertlllter
farmland. produced la baaed on I»»J
fjOi data for ferllllier
production and 201 rjOt
I* familiar.
Applied to Tlie quantity of fertllltrr
farailand. produced la baaed on I9>3
r20) data fur ferllllter
production and 471 r>iOj
la fertlllter.
Applied to The quantity of ferllllier
faralaod. produced la baaed on !••)
fjOj data fur pliukpliorlc
acid product Ion. une-third
of Mlilcli la uacil lo produca
ua plioeplialve. end
r,U» in fartlllter.
-------
A-8
Sources of Radiation and Exposure to U.S. Population*
Exposure(mrem/yr)
Natural Background Radiation
Cosmic (protons,muons,high energy e~) 27
Cosmogenic (H-3, C-14, B-7) 1
Terrestrial (U, Th, Ra, K-40) 28
Internal (K-40, Po-210 39
Inhaled (Radon and progeny) 200
Subtotal TOU
Man-made Radiation 60
includes: medical x-rays
nuclear medicine
consumer products
other(occupational, fallout
nuclear fuel cycle, misc.)
Total Exposure* 360 mrem/yr
from National Council for Radiation Protection and Measurements,
Report 193, September 1, 1987.
-------
A-9
<-
f
/
iir I r
0 10cm 1m 10m 100m 1000m
Ptftir* (UAf« of fuicl«*r y«rticl*« in «ir vltn th« •••• «n«tfy (J NtV)
-------
A-10
THE URANIUM SERIES
-------
A-U
THE THORIUM SERIES
90
1.9yr
88
3.6da
220pn
88
56««c
232Th
90
1.4x10'°yr
228Ac
89
6.1hr
228Ra
88
8.7yr
212Po
84
3.0x10**sec
-------
A-12.
THE ACTINIUM SERIES
; 23SU?
72
7.1x10«yr
227JH
90
18da
223ft!
88
11da
86
4 s«c
216po
84
1.8x10'3««c
1
2nPb
82
231 Fa:
M
3;3x104yr
231 Th
90
26hr
227Ac
89
22yr:
-------
A-13
Engineering shorthand and greek prefixes.
GREEK PREFIX
maga
kilo
milli
micro
nano
pico
famto
ABBREVIATION
M
k
m
n
P
f
VALUE
1,000,000
1,000
1
1000
t
1,000,000
1
1,000,000,000
i /i .moiMri.floo.ooo
ENGINEERING
SHORTHAND
10*
10*
10'* C
10- c
10'* 0
10-"
ONE PART PER THOUSAND
ONE PART PER MILLIONlppm
ONE PART PER BILLION(ppb)
1/1,000,000,000.000,000
-------
Standards for Uranium Mill Tailings (40 CF3 192)
Uranium Mill Tailings contain uranium series radioactive
elements, including radium, and toxic nonradioactive hazardous
substances, sucb as molybdenum and selenium. The radium
concentrations vary from about one hundred to a few thousand
pCi/g. The major .risk pathways are:
o Diffusion of radon-222 (produced by radium-226) into
indoor air, either directly from a tailings pile or
where tailings were used in construction. Breathing
decay products of radon can cause lung cancer.
o Direct gamma radiation exposure.
o Dispersal of small particles of tailings material-in
the air. f
t
o waterborne transport of radioactive or nonradioactiive
toxic materials.
The major goals of the standards are twofold: (1) To
stabilize tailings piles so as to minimize their emissions and
the potential for human misuse of tailings, and (2) to remediate
existing and potential hazards posed by tailings that nature or
people have removed from the piles.
Objectives of the standards are summarized more
specifically below. (This is simplified paraphrasing; see
40 CFR 192 for the exact requirements.)
For Tailings Piles (disposal)
The standards require reasonable assurance of control of
radiological and non-radiological hazards to be
o effective for 1000 years, to the extent reasonably
acheivaoie, and, in any case, for at least 200 years,
o Reduce radon emissions to less than 20 pCi/m2secs,
o Conform to groundwater and surface water standards, and
o Eliminate excess gamma exposure.
In a stable location that is sufficiently above the water
table, these conditions may all be satisfied by a liner and
thick enough durable cover that is designed to keep radon in an?
water out. Importantly, such covers are significant barriers to
-------
A-15
inhibit access for misuse. The standard must be satisfied by
physical means rfnose long-term effectiveness does not depend on
institutional control. The Uranium Mill Tailings Radiation
Control Act, which authorized these standards/ provides the
important additional protection of government ownership of
disposal sites.
Cleanup of Buildings
Tailings have been used in building materials and under
buildings. Radon from these tailings accumulates indoors where
people spend most of their time.
o For buildings affected by tailings, take all
reasonable measures to reduce indoor radioactivity to
0.02 WL, primarily by removing the tailings, and the
gamma radiation to less than 20 uR/hr above background.
This not only reduces hazards in existing buildings but'
would avoid perpetuating the hazard in future replacement
buildings.
Cleanup of Land
Tailings have been removed from piles and deposited on open
land by either weathering or deliberate human actions.
weathering tends to disperse tailings in thin layers at low
concentrations. Human removals, even where tailings were mixed
with other materials, tend to be of bulk materials and to retain
high concentration.
o Remove tailings deposits from open land if they are
greater than 5 pCi/g within the top 15 c..i, or greater
than 15 pCi/g below.
The objectives are to avoid future hazards from building on
such land, and to remedy any current unnecessary exposures.
Note that the concentration of displaced tailings generally
varies from their high original concentration of many hundreds
of pCi/9 to values approaching background (aoprox. 1 pCi/g).
This variation occurs gradually for weathered material, and
abruptly at the edges of bulk removals. Therefore/ any tailings
not cleaned up under the standard will generally be no more than
thin deposits, not bulk masses, that are below the concentration
limits.
The residual hazards will generally be much less than would
be expected frora oulk material deposits with concentrations at
the cleanup limits. These cleanup standards are designed to
reduce the potential hazard from an existing undesirable
------- |