DRAFT

SUGGESTED GUIDELINES FOR THE DISPOSAL OF

NATURALLY OCCURRING RADIONUCLIDES GENERATED BY

DRINKING WATER TREATMENT PLANTS

U.S Environmental Protection Agency

Office of Drinking Water

Criteria and Standards Division

March 1989

AcelvedwILir Dated Jp .

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TABLE OF CONTENTS

Page

Introduction ........ 1............................... 1

Purpose and Scope ..................................... 2

Summary of treatment technologies to removenaturally occurring radionuclides fromdrinking water ...... **............. .... .............. 3

Characteristics of wastes generated by watertreatment plants removing naturally occurringradionuclides from drinking water ........ .............. 6

Waste disposal alternatives ........... ............. e. 11

Guidance for the disposal of wastes-Liquid wastes ........ ........... 14

-Solid wastes ....................... 22

Radiation guidance for workers ........................ 33

References ............................................37

Glossary ..............................................41

Appendix .................................4

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Introduction

The naturally occurring radionuclides of concern indrinking water are the various members of three radioactivedecay series: the thorium series, the uranium series and theactinium (U-235) series. The members of these series aredistributed throughout the earth's crust and have existedsince the formation of the earth. Problems with water suppliesusually develop where high natural concentrations of one ormore members of these series occur. If waters draining fromor produced within areas of high radionuclide content aretreated for potable water supply use, the possibility ofgenerating significantly radioactive waste products exists,even if the treatment was not intended to remove radioactivity.

Not all radionuclides of these natural decay series areof concern; most have not been found in sources of drinkingwater supply at levels indicative of a risk to public health.Thorium, for example, is virtually insoluble in waters thatwould be considered for potable use. While radium-228, adaughter product of thorium, may occur in drinking water atlevels that would necessitate treatment for removal. Teradionuclides of potential concern in drinking waters or intreatment 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 isotopesof polonium, lead, and bismuth.

The National Interim Primary Drinking Water Regulations(l)(NIPDWR) estabilished maximum allowable contaminant levels(MCLs) for radium and gross alpha radiation levels in drinkingwaters. At that time uranium and radon was excluded from theregulations due to insufficient information on their occurrenceand toxicity. The Environmental Protection Agency(EPA) isrevising the NIPDWR. Under the new regulations the NationalPrimary Drinking Water Regulations (NPDWR), MCLs for radiumand gross alpha will be revised and the EPA will propose MCLsfor radon and uranium.

Water supply systems which distribute waters containingradium, radon or uranium above the tICL will have to implementcorrective measures to comply with the law. Treatment processessuch as ion exchange, lime softening, coagulation/filtration,reverse osmosis and others are capable of effectively removingthe radionuclides of concern from the drinking water. Thehandling and disposal of the wastes generated by the treatmenttechnologies removing naturally occurring radionuclides fromdrinking water, pose significant concerns to the water supplier,the local and State governments and to the public at large.

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Purpose and Scope

At the present time there are no federal regulationsspecifically addressing the disposal of wastes generated bywater treatment facilities on the basis of their naturallyoccurring radionuclide content. Unquestionably, wasteby-products produced by drinking water treatment facilitiescan be of sufficiently high radioactivity to warrant disposalguidance. Regulations and guidelines have been developeddealing with the handling and disposal of wastes containingnaturally occurring radionuclides originating from industriesother than water treatment. A number of these sources havebeen utilized to develop this guidance. They are referredto in the text.

The purpose of this document is to provide guidance to watersuppliers and to State and local governments for the proper hand-ling and disposal of waste byproducts from treatment facilitiesremoving naturally occurring radionuclides from drinking water.This document is not intended to be applicable to the use/disposalof sewage sludge. Separate regulations addressing the use/disposalof sewage sludge at 40 CFR Part 503 were recently proposed forpublic comment (54 Federal Register 5746; February 6, 1989).

This guidance specifically addresses only disposal of wastescontaining naturally occurring radionuclides from public watersupply treatment plants. However, as radiation health safetyis the guiding criteria, this guidance has implications forthe handling, transporting, regenerating, recycling and landapplication of other wastes containing radium, uranium andradon decay products, as well as their ultimate disposal.Similarly, a logical extension in principle to wastes producedby non-public supplies and point-of-use or point-of-entrytreatment of domestic water supplies could be made.

This guidance is to provide assistance where gaps in existingregulations may exist. However this guidance should not be usedto supercede regulations with more stringent provisions in effect.States may utilize these guidelines to assist them to developtheir own policies regulating the disposal of water treatmentplant wastes containing naturally occurring radionuclides.

The States of Illinois(2) and Wisconsin(3) have developeddisposal criteria of water treatment plant wastes containingradium. The Conference of Radiation Control Program Directorsis developing suggested standards for the disposal of naturallyoccurring radioactive wastes(4). Similarly, New Hampshire(5)Colorado(6) and other states have addressed the disposal ofwastes containing naturally occurring radionuclides. The EPAOffice of Radiation Programs (ORP) is expected to propose in1989 regulations controlling the disposal of wastes containingnaturally occurring radionuclides in excess of 2000 pCi/g, underthe authority of the Toxic Substances Control Act (TSCA),Section 6. At a later date, EPA is considering the developmentof regulations addressing the disposal and use of wastesthat contain less than 2000 pCi/g of naturally occurringradionuclides.

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Summary of Treatment Technologies to Remove NaturallyOccurring Radionuclides from Drinking Water

There are a number of different treatment techniquesavailable to remove naturally occurring radionuclides ofconcern from drinking water. Some of these technologies havebeen used extensively to remove contaminants other thanradionuclides from water, while others are designed for theremoval of a specific radionuclide. The processes that areeffective to remove radionuclides include the following.

Cation Exchange for Radium Removal

Cation exchange using natural or synthetic resins to replacecalcium and magnesium ions is a commonly used technology. Thesame ion exchange resins that are used to soften water can beused to remove radium from the drinking water. Experienceindicates that a well operated ion exchange softening plant canremove up to 97% of the radium from the drinking waterl7,8,9,10,11).Since radium removal still takes place after the resin isexhausted for hardness, regeneration of the resin to achievegood hardness removal will also assure good radium removal.

Greensand Filtration for Radium Removal

This technology has been used to remove iron and manganesefrom the water. The iron and manganese is removed by passingthe water through a greensand filter of natural or syntheticmedia after oxidation by potassium permanganate. This is acontinuous process, except when the process is interrupted byfilter backwash. Experience in Iowa(7) and Illinois(8) indicatesthat up to 56% of the radium is also removed. In a more recentpilot plant study, the removal of radium reportedly was improvedto 90% by passing the water through a detention tank afterthe addition of potassium permanganate prior to filtration(l6).

Coprecipitation of Radium with Barium Sulfate

Addition of a soluble barium compound, such as bariumchloride, to the water containing radium and sulfates willcause both the radium and barium to coprecipitate to form ahighly insouble barium sulfate sludge containing the radiumremoved from the water. This process has been primarily usedto remove radium from waste effluents. Experience with minewastewaters indicate that this process is capable of removingover 95% of radium from water. At the present time , thereis one full-scale drinking water treatment plant, located inMidland, South Dakota, utilizes this process. Radium levelsin the water at this facility are reduced from 16 pCi/L toless than 1 pCi/L(18).

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Anion exchange for Uranium Removal

Anion exchange resins have been used to recover uranium frommine process waters. Laboratory and field studies have verifiedthat anion exchange resins can be suitably adopted to removeuranium from drinking water. Anion exchange resins have beenshown to remove over 95% of the uranium from water(lO,1I 2,1 3,14).Anion exchange resins have very large adsorbtion capacity foruranium, in some instances exceeding 20,000 bed volumes of treatedwater(IO).

Coagulation/Filtration for Uranium Removal

This treatment technology has been widely used by the watertreatment industry to make the water suitable for potable use.Although this technology is not applicable to the removal ofradium from drinking water, limited information indicates thatunder suitable operating conditions it can be effective for theremoval of uranium. Results of laboratory studies have demon-strated that the effectiveness of iron coagulants and alum toremove uranium from water is highly sensitive to pH(l2 rl3).The removal efficiency at a specific pH level depends on theprevailing charge on the floc and the uranium species present.Best removal efficiencies, 85 to 95%, have been encountered atpH levels of 6 and 10. Use of coagulant aids, such as polymershas resulted in improved removal of uranium in an operatingwater treatment facility at Arvada, Colorado(l3).

Lime Softening for Radium and Uranium Removal

Lime softening is a commonly used process to remove hardnessfrom drinking water. Addition of lime removes hardness by theformation of insoluble calcium carbonate and magnesium hydroxide.It has been shown that at elevated pH levels lime softening isvery effective to remove radium and uranium from drinking water.Experience in the field and the laboratory demonstrated that limesoftening can remove 75 to 90% of the radium from drinking waterprovided pH levels are maintained above 10(8,9,11).

Laboratory studies indicate that lime softening is 85 to 90%effective in the removal of uranium from drinking water. Theremoval efficiency can be improved up to 99% by the presence orthe addition of magnesium carbonate to the water(l2, 14).

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Reverse Osmosis for Radium and Uranium Removal

Reverse osmosis is a process that is commonly used in areaswhere water has high total dissolved solids concentrations. Thisprocess uses semi-permeable membranes that allow the passage ofwater but reject the dissolved salts. Pressure is required toforce the water through the membranes. The process is continuous,with the treated or "recovered" water passed to storage and todistribution for potable use, and the rejected concentrate dischargedas a concentrated liquid waste stream. Reverse osmosis have beenshown to be highly effective for removing inorganic contaminants,including heavy metals and radionuclides such as radium and uranium.It has been demonstrated that reverse osmosis can remove 87 to 98%of radium and 98 to 99% of uranium from drinking water(l4,l5).

Granular Activated Carbon for Radon Removal

Granular activated carbon (GAC) has been used for the removalof organic contaminants and for taste and odor control. Recentlythis technology has been used for the removal of radon from drinkingwater. GAC treatment for radon removal was found to be attractivebecause most of the adsorbed radon decays within the carbon bedbefore breakthrough. Because of radon decay effective life ofthe carbon bed is extended many times over the life indicated bythe adsorbtion isotherm. However, the decay of radon on the GACmedia may result in the build-up of radon-222 decay products (seep. A-12) such as lead-210, and the radiation of low-level gammaactivity near the GAC unit(l9). The build-up of lead-210 in GAChas been estimated for various levels of influent radon concentration,and the result is shown graphically in the Appendix, pA-6. Theextent of this problem, including the disposal of spent GAC mediacontaining radionuclides, should be given full consideration beforeimplementing this technology. Pilot plant studies have indicatedthat activated carbon will also capture some uranium and radiumfrom drinking water, which further underscores the need to exercisecare in the planning of treatment and waste disposal options.Dependent on design, granular activated carbon is capable of removingup to 99% of radon from drinking water.

Aeration for Radon Removal

Various aeration processes, such as packed tower aeration, slattrays, diffused aeration and spray aeration are capable of removingover 99% of radon from drinking water, dependent on several designparameters(20). These processes have been used widely for the removalof volatile contaminants and the oxidation of inorganic contaminantssuch as iron in drinking water. Some States may limit the use ofaeration technologies for radon removal because of concern for humanexposure due to air emissions. However, preliminary analysis by EPAindicates that an aeration unit which emits radon and allows adequatedispersion of the gas in ambient air would not result in a significanthealth risk to the local population. Local limitations, concentrationof radon in water, emission rates, cost of treatment alternatives,and other site-specific factors should be given full considerationbefore implementing any technology for radon removal.

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Other technologies

There are a number of other treatment technologies that arecapable of removing radionuclides from drinking water. Howeverthey have not been extensively used in drinking water treatmentor have been used only experimentally. These technologiesinclude the use of selective sorbents(l6,2l,22) such as acrylicfibers or resins impregnated with manganese dioxide for removalof radium from water, and electrodialysis. Limited experimentalstudies have shown that activated alumina is capable of achievinggood removal of uranium from drinking water. In addition, cationexchange resins other than sodium ion exchange have demonstratedeffective radium removal capability(23).

Characteristics of Wastes Generated by Water Treatment PlantsRemoving Naturally Occurring Radionuclides from Drinking Water

In general, the amount of the radionuclides contained inthe wastes produced by the various treatment processes dependupon a number of site-specific factors such as:

o Concentration of contaminant in raw water

o Removal efficiency of the treatment process

o Frequency of regeneration of exchange resins

o Frequency of filter backwash

o Frequency of replacement of the carbon orother sorbent bed

o Loading capacity of the resin or sorbent

O Coagulant or lime dosage rate and raw water pH

* Radionuclides retained in sludge and in supernatant

o Reverse osmosis membrane type and operating pressure

The contaminants removed from the water are essentiallyconcentrated in the wastes produced by the treatment process.With the exception of aeration, the wastes produced by thetreatment processes may include solids (such as sludge) and/orliquids. Aeration produces a gaseous waste stream which, ifreleased to the atmosphere, forms a contaminant plume whicheventually disperses. The concentration of radionuclides (radonand its daughter products) in the plume would depend on influentradon concentrations, design parameters, and atmospheric conditions.

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For the purpose of these guidelines "solid" and "liquid"wastes containing radioactivity are defined:

Solid wastes will mean the sludges which result from settlingor 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 ofwater treatment and contain residual radioactivity.

Liquid wastes will mean the rinse and backwash waters, regener-ant solutions, supernatants, reject waters, waters removed duringsolids concentration procedures or other waste waters which areby-products of water treatment and contain residual radioactivity.

In greater detail, the following is a description of thewastes that are produced by the various water treatment processeswhich remove naturally occurring radionuclides.

Ion exchange wastes

The wastes produced by ion exchange treatment includeliquid waste containing brine, rinse and backwash water, andcontaminants stripped off the resin. In addition, the resinitself is a solid waste containing the contaminant exchanged.The amount of radium or uranium contained in the resin is dependentupon its loading capacity and whether it is disposed prior to orafter regeneration. The volume of waste stream produced by thecation exchange process to remove radium from drinking watertypically ranges between 2 to 10% of the product water. Theconcentration of the radionuclides in the waste stream producedby the ion exchange pocess depends upon the amount of radio-nuclides removed from the resin, the amount of regenerant usedand the frequency of regeneration. In a study performed in Iowa,the radium levels in the waste streams from the regenerationprocess were observed to range from 110 to 530 pCi/L (with apeak recorded at 3500 pCi/l) in the softener rinse and brine(24).Other data, provided by Wisconsin, indicated average and peakconcentration levels of radium in regenerant wastewater of23.1 pCi/L and 158.2 pCi/L, respectively. The radioactive build-up in a cation exchange resin removing radium in the same watertreatment facility was 8.70 pCi/g of combined radium.

Anion exchange resins have been found to have a very highloading capacity for uranium. Experience indicates that theseresins can treat as much as 20,000 bed volumes of water betweenregenerations(l0). Consequently, the regenerant liquid wastes willcontain high levels of uranium. Experience in the laboratory andpilot plant studies have shown that, with an influent uraniumconcentration of approximately 150 pCi/l, an average waste streamconcentration of 2 mg/l (or 1350 pCi/l) and as much as 25 mg/L(or 17,000 pCi/l) of uranium can be contained in the regenerant

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waste stream, if the resin is operated until breakthrough(l3).Because of their affinity for uranium, high radioactive buildupswill occur in anion exchange resins. Additional informationregarding radium and uranium in ion exchange regenerant wastesare shown in the Appendix, p. A-4.

Lime softening wastes

The wastes generated include lime sludge which is precipitatedduring the process of removing the radium or uranium. Additionalwastes are generated by the the backwashing of the filters. Liquidwastes include the supernatant from the sludge and filter backwash.The concentrations of the radium or uranium in the lime sludge andthe filter backwash sludge may vary between individual water treatmentplants, dependent upon the concentration of the radionuclides in thesource water and the lime dosage added during the treatment.Experience with operating lime softening facilities indicate thattypical radium concentration levels range from 1,980 to 2,500 pCi/Lin the lime softening sludge, 6 to 9 pCi/g in the dried sludge and6 to 50 pCi/L in the filter backwash water. Radium levels in thesupernatant over settled sludge was found to range between 21 and24.4 pCi/L(24). For additional data refer to the Appendix. Thereare no operating plant data regarding the levels of uranium in thewastes generated in a lime softening water treatment facility.

Coagulation/filtration wastes

The wastes generated in this process include iron oralum sludges from the contact and settling basins and from thefilter backwash. The supernatant from this sludge comprises aliquid waste. Additional liquid waste is generated when thesludge is concentrated prior to disposal in a landfill. Theamount and activity of contaminants such as uranium in the sludge,is dependent upon the removal efficiency of the process, theconcentration of contaminants in the raw water, and the dosageof coagulant applied. Uranium concentration in sludges has beenestimated to be from 10,000 to 30,000 pCi/l for uranium raw waterconcentrations in the range of 30 to 50 pCi/l.

Reverse osmosis and electrodialysis wastes

The wastes from these processes are the reject streams, whichare continously generated during the treatment process. The amount ofradionuclides in the reject stream is dependent upon the operatingremoval efficiency as well as the influent concentration levels. Forinstance, if a reverse osmosis (RO) plant removes 98% of the radio-nuclides from the drinking water and rejects 50% of the source wateras waste, the concentration level of radionuclides in the rejectedwaste water would be 1.96 times greater than the concentration levelsof radionuclides in the raw water. Results of studies by EPA indicatedthat radium concentration levels in the reject waters of RO facilitiesremoving radium from drinking water ranged from 7.8 to 37.9 pCi/L(15).These results are shown in the Appendix, p. A-3.

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Greensand filtration wastes

The wastes generated by this process include sludge, andsupernatant from the filter backwash. Concentration levels ofradium in the filter backwash have been found to range between65 and 169 pCi/L(25).

Co-precipitation of radium with barium sulfate

The wastes generated by this process include barium sulfateprecipitant sludge containing the radium removed from the water,filter backwash, and supernatant from the sludge(26).

Selective sorbents

Selective sorbents used to remove radium from drinking waterare not regenerated. Experience indicates that the sorbent loadingcapacity can produce radium concentration levels within the mediaof 110,000 pCi/g, dry weight(23).

Granular activated carbon (GAC) wastes

GAC that is used to remove radon from drinking water willretain and accumulate the decay products of radon( 7), which includeradioactive isotopes of polonium, lead, and bismuth. In addition,GAC systems in New Hampshire and Maine have shown that GAC willremove uranium as well as radon from drinking water. Preliminarydata from New Hampshire also suggest that GAC may also removeradium. According to these data, the observed uranium concentra-tion on the carbon was 258.5 uCi/m3 (28), or about 580 pCi/g. Theamount of radium and uranium (if present) retained by the GACdepends upon its loading capacity. This loading capacity isreached long before the carbon is expected to be replaced on thebasis of radon adsorbed.

However, because of its relatively long (20 year) half-life,lead-210 levels in a carbon bed will increase during the servicelife of the carbon. The amount of lead-210 retained by GAC bedsremoving radon from drinking water has been estimated (as shown inthe Appendix, p. A-6, for a small GAC unit). Lead-210 is a betaparticle emitter and decays to bismuth-210(a beta emitter),polonium-210(an alpha emitter) and lead-206, which is stable andnon-radioactive. Because of the relatively small amounts ofradon present in water, it is estimated that it would requireseveral years before the capacity of a GAC bed for radon decayproducts is exceeded. In instances where organic contaminantsare present in the water, the length of the service life of thecarbon bed will be governed by the breakthrough of the organiccontaminant.

The following table is a summary of the types of wastes thatwould be generated by various drinking water treatment techniques.

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TABLE 1

Summary of Treatment Technologies and Wastes ProducedDuring the Removal of Naturally Occurring Radionuclides

from Drinking Water

TREATMENTTECHNOLOGY

CONTAMINANTREMOVED WASTE(S) PRODUCED

CationExchange

AnionExchange

Radium

Uranium

Rinse and backwash water,brine regenerant solution.

Rinse and backwash water,brine regenerant solution.

LimeSoftening

Coagulation/Filtration

ReverseOsmosis

GreensandFiltration

RadiumUranium

Uranium

RadiumUranium

Radium

Sludge from settling tanks,filter backwash, supernatantfrom settling or concentratingsludge and filter backwash.

Sludge from settling tanks,filter backwash, supernatantfrom settling or concentratingsludge and filter backwash.

Reject water

Solids and supernatant fromfilter backwash.

Coprecipitationwith BaSO4

GranularActivatedCarbon

SelectiveSorbents

Aeration

Radium

RadonUranium

Radium

Radon

Sludge from settling tanks,filter backwash, supernatantfom settling or concentratingsludge and filter backwash.

Granular activated carbonmedia

Selective sorbent media

Radon released into air, orradon decay products accumu-lated on off-gas contactors(i.e., GAC media)

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Waste Disposal Alternatives

Traditionally, waste streams produced by water treatmenthave been discharged into sanitary sewers, receiving waters,injected into deep wells or otherwise disposed underground,and the sludges disposed into landfills or spread on land.At present, there are no federal regulations specificallyaddressing the disposal of wastes on the basis of their naturallyoccurring radionuclide content. However, there are otherfederal regulations that are applicable to the discharge anddisposal of water treatment wastes into navigable waters, onland, or by deep well injection. In many areas State and locallaws already limit the the discharge of wastes containingradionuclides into the environment. Disposal of wastes intostreams or sanitary sewers may be limited. In some instances,pretreatment of waste streams may be required before ultimatedisposal by controlled discharge.

Where disposal of water treatment wastes is restricted,the waste generatormay resort to the use of evaporating lagoons. However thismethod is only practical if sufficient land is available at lowcost and the evaporation rate exceeds the rainfall. Where landis not available, sludges generated by the treatment processesmay be dewatered by centrifugation or by vacuum filtration.The concentrated sludge may be disposed of as recommended inthis guide. In many instances, if good separation occurs, thesupernatant from the settling tanks may be recycled to theintake of the water treatment plant. This practice will reducethe amount of wastes to be handled and disposed.

Concentration of wastes will reduce the volume that has to beultimately disposed. However, at the same time, concentrationsof radionuclides and other contaminants in wastes will increase.Disposal of concentrated wastes and sorbents and high capacityresins that are not regenerable may require special handlingand disposal because of the accumulation of high concentrationsof radionuclides. Similar precautions may be warranted with thehandling and disposal of spent granular activated carbon thathas been in service for extended periods for the removal ofradon from drinking water. Accumulation of radon decay products,and other radionuclides present in the water such as uranium,can contribute to increased levels of radioactivity in thecarbon bed.

For small water supply systems, disposal of wastes generatedby water treatment may be more difficult. A large number ofsmall communities do not have sewage systems. Therefore, somedispose their sewage and other water treatment by-products intoseptic tanks (which is not an EPA suggested disposal method).Such facilities may not be able to handle the brines or otherwastes generated by water treatment facilities removing radio-nuclides from water. In instances where radionuclides areconcentrated in the waste stream, discharge into septic tankswould not be an appropriate method of disposal. Other options

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would have to be evaluated, and if appropriate waste disposalsites or waste treatment facilities are not available thesecommunities may be required to have the wastes hauled awayfor disposal at an appropriate site by contractors.

Water treatment plants removing uranium from drinking waterby anion exchange may haul the regenerant waste and discardedion exchange resin to a uranium wastes facility or mill tailingssite. This option of waste disposal may be an economicallyfeasible alternative, provided the uranium facility issufficiently close and is willing to accept the material.

Table 2, below, summarizes current disposal alternativesfor wastes generated by treatment facilities removing naturalradioactivity from drinking water.

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TABLE 2

Summary of Current Disposal AlternativesFor Wastes Generated by Water Treatment Facilities

Removing Naturally Occurring Radionuclides from Water

Liquid Waste Disposal Alternatives

• Direct discharge into storm sewers or surface water

° Discharge into sanitary sewer

o Subsurface disposal

o Drying or chemical precipitation

Solid Waste Disposal Alternatives

o Temporary lagooning (surface impoundment)

° Disposal in landfill (mixed or impounded dependingon concentration of wastes)

a) disposal without prior treatment(resins, filter media, GAC)

b) with prior temporary lagooningc) with prior mechanical dewatering

o Application to land (soil spreading/conditioning)

o Disposal at low level radioactive waste facility

Use Alternative

o Recovery of uranium from resins and regenerants

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Guidance for the Disposal of Wastes Generated by Water TreatmentPlants Removing Naturally Occurring Radionuclides

Federal, State and local laws and regulations governingthe disposal of water treatment wastes must be complied withwhen following these guidelines. Regulations that are morestringent, limiting the options for the disposal of watertreatment wastes based upon its radioactivity or hazardousnature, supersede the guidelines recommended below.

Liquid wastes

The following is a discussion of the federal standardsand the rationale used in. formulating the disposal guidelinesand respective concentration limits suggested herein.

o Disposal into storm sewers and surface waters

Section 402 of the Clean Water Act requires that dischargersof pollutants to navigable waters obtain National PollutantDischarge Elimination System (NPDES) permits containing, ata minimum, technology based effluent limitations reflectingvarious levels of wastewater treatment and, where necessary,more stringent limitations necessary to assure attainment andmaintenance of State water quality standards. EPA has notpromulgated any rule establishing technology-based effluentlimitations applicable to water treatment plants nationwide.In the absence of such a categorical standard, limitationsare established on a case-by-case basis using best professionaljudgment. After determination of minimum technology-basedrequirements, the effect(s) of discharge on the receivingwater is determined, and if necessary more stringent limitationsare established to protect the receiving water quality. Incertain States, water quality standards may include specificcriteria for radionuclides. State water quality standardsthat require more stringent discharge limitations supersedethe ones suggested in this guidance.

EPA has established regulations limiting the discharge ofpollutants, including naturally occurring radionuclides, intonavigable waters from existing and new sources in the oremining and dressing industry. The effluent limits, includingthe discharge of liquid radioactive wastes from the uraniummining industry, are contained in 40 CFR 440, Subpart C. Theeffluent limitations for existing sources represent reductionsattainable by the application of best available technologyeconomically achievable (BAT) for those industries, which isthe Clean Water Act standard for effluent limits. Thesesuggested guidelines for the discharge of liquid wastescontaining radium and/or uranium from water treatment plantsare identical to the discharge limitations contained in 40CFR 440(29).

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The following are suggested guidelines for dischargeof drinking water treatment liquid wastes containing radiumor natural uranium to surface waters and to storm sewers:

a) The maximum daily concentration of Ra-226, dissolved andtotal, should not exceed 10 pCi/1 and 30 pCi/l, respectively.

b) The maximum daily concentration of uranium should notexceed 2700 pCi/l*(or 4 mg/i).

c) The average of daily concentrations of Ra-226, dissolvedand total, for 30 consecutive days should not exceed 3 pCi/land 10 pCi/l, respectively.

d) The average of daily concentrations of uranium for 30consecutive days should not exceed 1350 pCi/l*(or 2 mg/1).

It should be noted that the ore mining standards whichformed the basis for the above guidelines do not addressRa-228 in wastes. It would be appropriate to consider applyingto Ra-228 the same above-stated Ra-226 discharge limits.

* Uranium concentrations in pCi/1 are based on the assumptionthat the overall activity-to-mass ratio for total uranium indrinking water is 0.68 pCi per ug. Concentrations in mg/lare directly taken from the ore mining regulations(40CFR440).

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° Disposal into sanitary sewers

Other than general pretreatment regulations, thereare no specific Federal regulations governing the dischargeof wastes from water treatment plants into sanitary sewers.However, certain States or localities may limit the dischargeof wastes from water treatment plants into the sanitary seweror may require pretreatment of the waste prior to release intothe sanitary sewer. Where they are more restrictive than theguidelines provided here, State or local regulations limiting thedischarge of water treatment wastes containing naturallyoccurring radionuclides into sanitary sewers supersede thelimits recommended herein.

The Nuclear Regulatory Commission (NRC) establishedlimitations on the discharge of wastes containing radioactivematerials, from NRC licensees, into sewer systems. These arecodified in 10 CFR Part 20, sections 20.1(c) and 20.303 30).

The recommended guidelines for the discharge of liquidwastes containing radium and/or uranium from water treatmentfacilities into sanitary sewers are identical to the dischargelimitations contained in 10 CFR 20, listed in Appendix B,Table I. In addition to complying with the recommendedlimits, facility operators should make every reasonableeffort to reduce the release of radioactive materials intothe environment to as low a level as reasonably achievable(as NRC licensees are required, under Part 20). "As low asreasonably achievable" means taking into account the stateof technology to reduce discharge of contaminants, the costof improvements and benefits to public health and safety.

The following are suggested guidelines:

a) The daily quantity of soluble radium-226, diluted by theaverage daily quantity of water treatment wastes releasedinto the sewer, should not exceed 400 pCi/L.

b) The daily quantity of soluble radium-228, diluted by theaverage daily quantity of water treatment wastes releasedinto the sewer, should not exceed 800 pCi/L.

c) The daily quantity of soluble uranium (natural), dilutedby the average daily quantity of water treatment wastesreleased into the sewer, should not exceed 1 uCi/L.

d) The above concentrations, once determined, should beapplied to the following relationship. The sum of theratios should not exceed "unity", as follows:

CRa-226 + CRa-228 + CU < 1 where:400 800

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CRa-226 concentration of soluble radium-226 in the wastewater(pCi/L)

CRa-228 = concentration of soluble radium-228 in the wastewater(pCi/L)

CU = concentration of soluble uranium in the wastewater(uCi/L)

Soluble means readily dispersible in the ambient water orwastewater (the NRC does not allow discharge to sewerage unlessthe materials discharged are soluble in water).

If accumulation of radioactivity in the sanitary sewagedistribution system or in the sewage treatment facility (orpublicly owned treatment works) is observed, discharge ofradioactive wastes into the sanitary sewer should be discontinueduntil radiation exposures and possible hazards to personnelrepairing sewage pipelines are evaluated. Discharge ofwastes containing radionuclides into the sanitary sewerwill result in the accumulation of radionuclides in thesludges produced by the wastewater treatment plant, as shownin the Appendix (p. A-5).

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o Subsurface disposal

Under Part C of the Safe Drinking Water Act (SDWA)EPA is required to promulgate minimum requirementsfor effective Underground Injection Control (UIC) programsto prevent endangerment of underground sources of drinkingwater by subsurface emplacement of fluids through wells.These minimum requirements are currently promulgated at40 CFR Parts 124, 144, 145, and 146.

The regulations may be implemented by States thathave adopted requirements at least as stringent as theFederal requirements and have been given primary enforcementresponsibility for the UIC program (Primacy States).Requirements for States to assume are codified at 40 CFR 145.For States that do not have primacy, EPA has promulgatedState-specific regulations that are implemented by EPA regionaloffices. State-specific regulations have been codified at40 CFR Part 147 and Parts 124, 144 and 146.

A drinking water treatment plant owner interested indisposing of wastes containing radionuclides into aninjection well in a Primacy State should consult with theappropriate State Agency first since State regulations maybe more stringent than the Federal requirements and mayban such practice. The plant owner in a direct implementing(D.I.) State should consult with the appropriate UICRegional Branch office (EPA) before deciding to dispose ofwastes containing radionuclides into an injection well inaccordance with a method recommended below.

Under the Federal requirements, water treatment plantwastes containing radionuclides may or may not be definedunder the UIC program as radioactive, depending on theconcentrations of radionuclides. Radioactive wastes aretreated differently than nonradioactive wastes under theUIC program. As defined in 40 CFR S144.3, "RadioactiveWaste means any waste which contains radioactive concentrationswhich exceed those listed in 10 CFR Part 20, Appendix B,Table II, Column 2." For example, the concentration forradium-226 is currently listed as 30 picocuries/l, whilethe radioactive concentration for uranium (natural) is30,000 picocuries/l.

The following are suggested guidelines:

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1. Radioactive Wastes (Ra-226 >30 pCi/l, U >30,000 pCi/i)

Shallow injection of radioactive wastes (i.e., injectionabove or into an underground source of drinking water, or USDW)is a banned practice under the UIC program. Further, the UICprogram defines both USDWs and injection wells very broadly.A well is any bored drilled or driven hole where the depth ofthe hole is greater than the largest surface dimension. Thedefinition includes septic systems and cesspools used fordisposal of wastes. A USDW is an aquifer or its portionwhich supplies any public water system; or which contains sufficientquantity of water to supply a public water system and suppliesdrinking water for human consumption, or contains fewer than10,000 mg/l TDS. The combination of these two definitions makesit highly unlikely that any shallow disposal of radioactivewaste would ever be permissible under USDW regulation.

Wells used for disposal of radioactive waste below allUSDWs are considered Class V wells and are currently under studyby EPA as part of the Class V regulatory development effort.At this time the EPA is not prepared to make any recommendationsregarding these wells.

2. Nonradioactive Wastes (Ra-226 <30 pCi/l, U <30,000 pCi/l)

Wells used for shallow injection of nonradioactive wastesare considered Class V wells. As explained above, the EPA isnot making recommendations regarding Class V wells at this time.

Well injection of nonradioactive drinking water treatmentplant wastes beneath the lowermost USDW is classified as ClassI. EPA recommends disposal of nonradioactive waste through aClass I well because these wells must be permitted, andcurrent permitting requirements for these wells are extensiveand adequately protect USDWs and human health.

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o Other options

If, due to the properties of the liquid wastes or due tolocal regulatory restrictions, a liquid waste containingnaturally occurring radionuclides cannot be processed by theuse of one of the above methods, then the treatment operatormay 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 solidsseparation techniques. The resultant solids would be disposedof as recommended in the following section.

Figure 1 contains a flow diagram which summarizes thedecisions and options that may be available for the disposalof liquid wastes, according to the suggested guidelines.

.4

Figure 1Summary of Disposal Alternatives For Liquid Water Treatment Plant Wastes

Containing Natural Radioactivity

ILIQUID WP WASTESI

. -ILinitial monitoringfor radionuclides I

ISubsurface DisposalOption -Is waste classified asradioactive under40 CFR 144.3?

(

.

NO YESRa-226 (dissolved)max. daily <10Ra-226 (total)max. daily <30U maximum daily

<2700Also,averages over30 days re given

YES

*

NO

Ra-226 <400 pCi/l Ra-228 <800 pCi/lTotal UuCi/l) <1Ra-226+Ra228+U <1

400 800

AND, no accumulationof radioactivity in sewerage system

Jo

Discharge direct to stormsewer OR to surface waters- EPA 40 CFR 440 Subpart C

See"SubsurfaceDisposal'

Option Above

SanSewR.N

Injiconimet]40 1

YES NO

itaryser, NRCr. 10CFR 20

ction below formationstaining USDW**- thisIod is subject to:FR 144.6(a)(2)

lt-A

I

Injection below USDW, noguideline: Class V wellsunder study. Shallowinjection is restricted.

Residual solidsdisposal as guidedin next section

Evaporation, dryingIPrecipitation, orother separation

* Concentrations in picocuries per liter.daily quantity of water treatment plant

tahese concentrations are the activities diluted by averageliquid waste. **US(W is underground source of drinking water

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Solid Wastes*

All natural materials contain radioactivity. The nation-wide average concentrations of radium-226, thorium-232, anduranium-238 in soils are each about 1 pCi/g; virtually allState averages are less than 1.5 pCi/g.(3 1 Even averagelevels of soil radium are frequently associated with highrisks from indoor exposures to radon, a gaseous radioactivedecay product of radium. For this reason, in large enoughquantities, wastes that contain only a few times the averagebackground concentration of radium should not be disposed ofindiscriminately. Because the half-life of radium is 1,620years, a long-term perspective of its potential hazard isnecessary. The half-lives of some thorium and uranium isotopesare tens of thousands to billions of years.

A. Existing Regulatory Framework

Disposal of solid wastes containing naturally occurringradioactivity, including water treatment wastes, falls underthe authority of the Resource Conservation and Recovery Act(RCRA). Under RCRA a "solid waste' is any discarded materialthat is not excluded under 40 CFR sections 261.4(a) or 260.30and 260.31, which are variance provisions. Under S 261.4(a)"source, special nuclear and by-product materials," as definedby the Atomic Energy Act of 1954, as amended, 42 U.S.C. 2011et seq., are excluded from the definition of solid waste underRCRA but are subject to Atomic Energy Act provisions.

The Environmental Protection Agency has established aclassification scheme for designating RCRA solid wastes as"hazardous" if they exhibit specified characteristics ofignitability, corrosivity, reactivity, or EP toxicity, asdefined under 40 CFR 261, Subpart C, or if they are listed ashazardous in Subpart D. Radioactive solid wastes from drinkingwater treatment are not currently regulated as "hazardous"under these RCRA criteria. Where radioactive waste is mixed withRCRA hazardous waste, the mixture is subject to RCRA Subtitle Cregulation. Radioactive releases ?-om these wastes could causea solid waste disposal facility to violate the RCRA groundwaterprotection criteria that are set forth in 40 CFR 257. ThePart 257 criteria are applicable to radium and gross alphaparticle activity (excluding radon and uranium) as well asfor other contaminants for which drinking water MCLs havebeen promulgated by EPA. Facilities that violate the criteriain Part 257 are deemed to pose a reasonable probability ofadverse effects on health or the environment. EPA has proposednew standards under the authority of RCRA and S405(d) of theClean Water Act, at 40 CFR 258 (53 Federal Register 33314,August 30, 1988), which would exclude municipal solid wastelandfills from the criteria in Part 257, and would apply Part258 criteria to municipal landfills which accept both householdwastes and sewage sludges. Unless otherwise amended, theseguidelines suggest that the criteria in 40 CFR 257 be appliedto all landfills accepting solid wastes from water treatmentplants.

* The disposal guidance herein is based solely on the radio-activity characteristics of these wastes and does not addressany other potentially hazardous substances they may contain.

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In addition, EPA proposed in the Federal Register (March 7,1989) disposal standards under Section 112 of the Clean Air Actand standards under the Uranium ill Tailings Radiation ControlAct at 40 CFR 192(32) specifically for the cleanup and disposalof uranium mill tailings, a sand-like material that containsradium, uranium, and thorium, usually in concentrations of onehundred to a few thousand pCi/g, and nonradioactive toxicsubstances. Tailings, a residue from the partial extraction ofuranium from ore, are deposited in very large "piles" adjacentto uranium mills. The standards (summarized in Appendix A,p. 14) serve two major objectives: (1) to clean up tailingsthat nature or people have removed from the piles, in order toreduce existing and potential hazards they may pose, and (2) todispose of tailings piles by stabilizing them so as to minimizetheir emissions and the potential for human misuse of tailings.

The disposal standards apply to the long-term control ofbulk tailings. The disposal standards for uranium mill tailingsmay provide useful guidance for the disposal of those watertreatment wastes that have radium concentrations from severaltens to several thousands of pCi/g (although concentrations ofthe latter magnitude are expected to be rare in water treatmentwastes). For reasons described further in the Appendix, themill tailings cleanup standards are not relevant to disposalsituations. They were designed only to reduce the potentialhazard from dispersed tailings to the lowest reasonablyachievable level.

Finally, in 1989 EPA expects to propose, under the authorityof the Toxic Substances Control Act, Section 6, standards forlow-level waste(34) that will provide disposal criteria for,among other things, wastes containing more than 2,000 pCi/g ofnaturally occurring radioactive materials.*

B. Disposal Rationale for Radium-bearing Solid Wastes

Minimizing future hazards is essential for radium-bearingmaterials because the potential indoor radon hazard is so large.The average radium level in soils of about 1 pCi/g is associatedwith an average indoor radon level of about 1 pCi/l, and alifetime 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 releasesfrom radium persist for thousands of years. It is clear, then,that even doubling the radium level in soil can have serioushealth risk implications, especialy if the increase occurs overa large area.(35)

*In addition, a Nuclear Regulatory Commission Branch TechnicalPosition(33) presents options for storage of thorium and uraniumwaste from past operations. These are often contaminated soilsfor which there may be little practical alternative to on-siteburial. The NRC reviews and approves each licensee's wastedisposal activities on a case-by-case basis. For these andother reasons, the NRC disposal options may not be appropriatefor newly-generated drinking water treatment wastes.

a

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Separate from the risk attributable to inhalation of radonand its decay products, radium-226 in soil at background levelsof 1 pCi/g can lead to an estimated lifetime risk level of approxi-mately 3 x 10-5 from ingestion (assuming an individual obtainshis/her total lifetime intake of vegetables, meat, and milkfrom land contaminated at this level) and 2 x 10-~ from direct,external radiation exposure (assuming continuous lifetimeexposure one meter above an infinite plane of soil contaminatedat this level). The other major naturally occurring radionuclidesthat may be generated by drinking water treatment plants,uranium and lead-210, do not have radon associated with them andthe risk from their ingestion or direct exposure is approximately10 times less than that from radium-226 at a given concentration.Lifetime cancer risks from typical background levels of U-238,and decay products, are shown in Table 3.

Table 3. Risks From Ingestion and External Radiation FromTypical Background Valuesa of U-238 and Decay Products

LIFETIME CANCER RISK

U-238/U-234b Th-230 Ra-226c Pb-210 Po-210

Ingestiond 3x10-6 3x10-7 3x10-5 3x10-6 7x10-7

ExternalRadiatione 3x10-6 9x10- 8 2x10-4 3x10-7 9x1O0 1 0

a Value of all radionuclides are assumed to be 1 pCi/g in soil.b Includes Th-234, Pa-234m, 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 inreferences 37 and 38.

Based on the above discussion, the main principles thatEPA has used in determining the safe disposal of naturallyoccurring solid radioactive waste are:

1. Since average soil concentrations for radium alreadycorrespond to a relatively high lifetime risk, average soilconcentrations should not be allowed to increase by more than asmall amount in locations where public access is possible.

2. When wastes contain radium in concentrations abovebackground levels, but of still relatively low concentration,they should be placed in locations where they will not be closelyassociated with or later used beneath or around buildings, dueto the high risk associated with indoor radon.

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3. When h ier concentration radium wites are disposedof, they should be stabilized in a manner comparable to disposalof uranium mill tailings to prevent migration and human intrusionso that risks from direct exposure and ingestion will be minimized.

4. Since there is no radon risk directly associated withuranium and lead-210 and the risk from ingestion of and directexposure to uranium and lead-210 is about 10 times less thanthat from radium, concentration limits for these radionuclidesshould be about 10 times higher than for radium.

1. Low Concentration Radium-bearing Solid Wastes

Because of the high inherent radon risks posed by normalradium levels, even near background" wastes should not bedisposed of indiscriminately. It may be possible, however, toplace them so as to pose essentially no initial hazard and tominimize the likelihood of hazards from future uses. Thisprimarily means to select locations that are unlikely to becomebuilding sites and to configure the material so as to makereuse in large quantities unlikely without mixing it with othermaterials, so that no special controls over future use areneeded.

In this context, it is improbable that materials withconcentrations higher than about 3 pCi/g (a few times naturalbackground levels) could be disposed of without the need forpermanent physical barriers and institutional controls. Whilesuch wastes might readily be placed initially in an innocuouslocation, future hazards could not assuredly be avoided.

In view of the limited quantity in which water treatmentwastes with less than 3 pCi/g (dry weight) of radium are produced,it may be practical to adequately dispose of them in many commonoutdoor construction situations, where future re-excavation islikely to mix the waste with at least an equal amount of uncon-taminated material. Deposition in thin layers promotes futuremixing and reduces the likelihood that large amounts of materialabove the background level might ever be placed below buildings.Thick deposits, such as from filling-in gullies and ravines,should be avoided. Deposition in locales that are generallyflat, where the use of fill prior to new construction is notrequired, would also minimize the likelihood of misuse. Examplesof this method are initial placement in road beds, sewer linebeds, etc. However, due to potential infiltration of radiuminto sewer lines, disposal of low concentration radium-bearingsolid wastes in sewer line beds should not be allowed unless itcan be demonstrated that the maximum level of radioactivitythat could penetrate the line would be equal to or less thanthe level recommended for direct disposal of liquid wastes intoa sanitary sewer (see p. 16-17).

Such wastes may also be placed in a municipal landfill.In this case, the sludges should be spread and mixed with othermaterials when emplaced, and when combined with other radioactivematerials placed in the landfill, should total only a smallfraction of the material in the landfill. This procedureshould provide adequate assurance that any future indoor radonhazard from the material will be minimal.

a eM

-26-

Alternatively, low concentration wastes may be used forsoil conditioning purposes on agricultural cropland (where anon-radiological component of the waste, such as alkalinity,is used to provide agricultural benefit). Ingestion and externalradiation risk estimates, due to average U.S. background levels,are given in Table 3. Here again one depends on the relativelysmall quantity of such wastes as an inherent limit on thepotential harm. To minimize this potential for any individual,the sludge should be deposited in a manner that assures thatthe radium concentration in the soil will not increase by morethan 0.1 pCi/g. At this concentration, the increased radiationrisk to the person with the maximum exposure to the soil would bequite low, i.e. an incremental risk of approximately 10-5.Nevertheless, repeated applications to the same field should beavoided.*

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 reasonableassurance that people will be protected from radon releases fromthe undisturbed waste and that the waste will be isolated toreduce the risk of disturbance or misuse. At these concentrationlevels, the radon risk associated with any building that may bebuilt on the disposal site and prolonged exposure to directgamma radiation from the material becomes a concern. Likewiseconstruction directly on the waste or its use in residentialconstruction is not appropriate. A properly designed physicalbarrier, i.e., a cover, seems best suited to achieve and maintainthe goals of reducing releases of radiation and inhibiting misuse.Supplementing such barriers with institutional controls designedto avoid long-term inappropriate uses of the site is also appro-priate, but, consistent with EPA policy, such institutionalcontrols may not be relied on for any assurance of protectionfor more than one hundred years. While the specific measuresneeded to achieve these goals at specific sites will vary withthe characteristics of the site, a physical barrier of ten feetof cover of earth or non-radioactive waste, if properly designedfor long-term stability of the waste and the cover if leftundisturbed, should usually suffice to achieve these objectives.The degree of protection a jurisdiction wants, to provideagainst intrusion and misuse, may vary with site location.

Where these objectives are met, and depending on sitecharacteristics, the quantity and the concentration of radiumin sludges in this range may not require additional featuresspecifically designed to isolate the waste contaminants fromgroundwater or to further reduce radon emissions to ambient air.A jurisdiction, for example, may choose to provide for groundwaterprotection by specifying RCRA hazardous waste requirements, suchas properly engi neered liners, to prevent seepage of contaminantsout of the landfill.

* This criterion for sludge disposal on agricultural land iscomparable to policies of the State of Illinois (angement ofWater Treatment Plant Sludge Containing Elevated Levels of Radium,Illinois Department of Nuclear Safety, December 1, 1987).

I

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Finally, small volumes of water treatment wastes in thisconcentration range may be diluted with non-contaminatedmaterials, such as ordinary earth, to a level below 3 pCi/g.The resulting material may be disposed of according to theguidance provided above for that category of wastes.

3. Radium-bearing Solid Wastes With Concentrations Between50 and 2,000 pCi/g (dry)

Individual situations should be assessed carefully anddisposal options evaluated thoroughly when concentrations exceed50 pCi/g. As the radium concentration increases, some of theassumptions made above become questionable. One needs a higherdegree of assurance that intruders will not be endangered, thatground water and ambient air pathways are adequately controlled,and that the site is adequately secure against natural disturb-ances, such as floods. More effective institutional controlsagainst future misuse of the site are needed than are generallyavailable, for example, for sanitary landfills. Disposal inconformance to the standards specified for uranium mill tailingsat 40 CFR 192(35) should be considered. A decision not to fullyemploy such methods should be based on a demonstration ofsignificant differences between the quantity and attractivenessfor inappropriate uses of uranium mill tailings and watertreatment wastes. EPA recommends that water treatment wasteswith radium concentrations exceeding 50 pCi/g be subject tosuch individual consideration by appropriate State and localauthorities.

At concentrations approaching 2,000 pCi/g, disposal ofwastes at licensed low-level radioactive waste disposal facilitiesshould be considered.

Wastes in this category should not be diluted below 3 pCi/g,for disposal by methods discussed in section (1), above. Becauseof the great waste volume expansion this would entail, and theattendant difficulties of isolating the material from people,disposal using methods for low concentration wastes may provideinferior protection. However, modest concentration reductions ofwaste materials near the lower end (50 pCi/g) of the rangeconsidered here may be reasonable.

4. Wastes Containing More Than 2,000 pCi/g (dry weight) ofNaturally Occurring Radioactivity

Based on draft standards for low-level wastes, expected tobe proposed by EPA in 1989, drinking water treatment wastescontaining more than 2,000 pCi/g of naturally occurring radio-activity should be disposed of in a low-level radioactive wastedisposal facility that is regulated under the provisions of theAtomic Energy Act.

a

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C. Disposal Rationale for Uranium and Lead-210 ContaminatedSludges/Wastes*

The risk from disposal of uranium or lead-210 contaminatedsolid wastes on land stems primarily from external gamma radiationand ingestion of foodstuffs grown or meat and milk from animalsgrazing on such land. Risks from typical background concentrationsof these and other radionuclides in the uranium decay chain aresummarized in Table 3 above. In addition to the risks shown inthe table, Ra-226 poses a potential inhalation hazard fromindoor radon described previously. The risk from radium-226and its short-lived decay products dominates the total riskfrom the uranium chain. Thus, it is important to establishwhat the level of radium-226 is in sludge before applyingguidelines for disposal of sludge contaminated with uranium orlead-210. Materials should be disposed of under the moststringent of the applicable guidelines.

Considering the long-term radiation risk from externalexposure or ingestion of uranium or lead-210, and assumingthere is little radium-226 present, there are three generalapproaches to disposal of uranium or lead-210 bearing solidwastes from water treatment, if:

° the concentration is sufficiently low, as defined in thefollowing paragraphs, the waste may be placed on land ina manner that affords adequate protection without insti-tutional controls,

o the wastes may be stabilized so as to provide long-termisolation against natural migration processes and humanintrusion, or

O if the concentration is sufficiently high, uranium wastesmay be processed for their uranium values.

The same control concepts apply for uranium and lead-210as for radium although the concentration levels associated witheach set of recommendations is increased by a factor of 10.This is due to the lower risk levels associated with uraniumand lead-210, as compared to radium.

Different concentrations of wastes can be disposed ofunder these general approaches in a manner that assures publichealth and environmental protection as follows:

1. Low Concentration Uranium or Lead-210 ContaminatedSolid Wastes

Low concentration uranium and lead-210 contaminated wastesmay be disposed of on land so as to pose essentially no initialhazard and to minimize the likelihood of hazards from futureuse. For example, land that is unlikely to be used for agricul-ture or buildings would meet this restriction. Further,

* Uranium must also be evaluated in terms of its chemicaltoxicity potential in addition to its radiological impact.These guidelines do not address chemical toxicity of uranium.

*0

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solid wastes should be placed so as to assure dilution in earthif any future activity is ever conducted. For example, spreadingthe wastes as fill material under roads or runways would meetthis restriction. In these situations, it appears reasonableto dispose of solid wastes up to about 30 pCi/g (uranium orlead-210), without need for permanent physical barriers andinstitutional controls.

Alternatively, low concentration wastes may be used forsoil conditioning purposes on agricultural cropland (as describedabove for low concentration radium-bearing solid wastes).Disposal of uranium and lead-210 contaminated wastes on agricul-tural land at 1 pCi/g above background yields an increased lifetimecancer risk from ingestion of vegetables, milk, and meat producedon the land of about 3 in one million. The incremental riskfrom external radiation from uranium is similar, and fromlead-210 about 10-fold less (Table 3).

2. Solid Wastes Containing 30 to 2,000 pCi/g (dry weight)Uranium or Lead-210

The disposal method for solid wastes containing 30 to 2,000pCi/g of uranium or lead-210 should be determined case-by-case.In general, it appears that disposal by standard municipallandfill practices would assure dilution and shielding to controlexternal radiation. However, such disposal should be examinedto ensure that sludges, in combination with other radioactivematerials, do not constitute a substantial fraction (greaterthan about 10%) of the total wastes in the landfill. Moreeffective physical stability and groundwater protection controlsand institutional controls against misuse may be needed wherelarge quantities of wastes are produced at the high concentrationend of this range. Disposal in the manner EPA provides foruranium mill tailings and hazardous wastes should be considered.

3. Solid Wastes Containing More Than 2,000 pCi/q of UraniumOr Lead-210

Guided by EPA's draft standards for low-level radioactivewaste, solid wastes with uranium or lead-210 concentrationsexceeding 2,000 pCi/g should be disposed of in a low-levelradioactive waste disposal facility operated under the provisionsof the Atomic Energy Act. Alternatively, uranium at theseconcentrations can be considered a resource, as discussed above.

D. Disposal Guidelines

The following guidelines apply to the disposal of radioactivesolid wastes from treatment of drinking water. The guidelinesaddress only naturally occurring radioactivity, and do not takeaccount of potentially hazardous nonradioactive constituents ofsuch wastes. Wastes containing mixtures of radionuclidesshould be disposed of under the most stringent applicableguideline. All stated concentrations refer to dry material.These guidelines notwithstanding, solid wastes from drinkingwater treatment processes should also be disposed of in compliancewith EPA landfill criteria in 40 CFR 257.

v

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1. Solid ,4wstes Containing Less Than YpCi/g (dry) of Radium,Or Less Than 30 pCi/g (dry) of Uranium or Lead-210

Wastes containing less than 3 pCi/g of radium or lessthan 30 pCi/g of uranium or lead-210 may be disposed of withoutthe need for long-term institutional controls provided that:

(a) the waste is placed in an initially innocuous location(such as a construction site, with due consideration of thepotential for infiltration of sewers, as mentioned above, p.25)in a manner that would promote mixing with clean material ifthe site were to be used for buildings in the future; or

(b) if deposited in a landfill, the wastes are spread andmixed with other materials when emplaced and, in conjunctionwith other radioactive wastes, constitute only a small fraction(less than about 10%) of the material in the landfill; or

(c) if spread on land for soil conditioning purposes, thewaste is spread and mixed so as to increase, on a cumulativebasis, the radium concentration in the soil by no more than0.1 pCi/g, and the uranium or lead-210 concentrations by nomore than 1 pCi/g.

2. Solid Wastes Containing 3 to 50 pCi/g (dry) of Radium

(a) These wastes should be disposed of with a physicalbarrier, i.e., a cover, that would protect against radon releaseand isolate the wastes, and provided with institutional controlsdesigned to avoid inappropriate uses of the disposal site. Aphysical barrier consisting of ten feet of cover of earth ornon-radioactive waste, properly designed for long-term stabilityof the waste, should suffice. Consideration should also begiven to the hydrogeology of the site and other factors affectinglong-term stability of the wastes. Sites that comply withEPA's Subtitle D regulations under the Resource Conservationand Recovery Act will be adequate disposal sites.

(b) Alternatively, small volumes of wastes in this concen-tration range may be mixed with other non-contaminated materials,such as ordinary earth, to yield a waste that qualifies fordisposal according to the guidelines of section 1, above.

3. Solid Wastes Containing 50 to 2,000 pCi/g (dry)of Radium

The disposal method should be determined case-by-case.Methods that comply with EPA's standards for disposal of uraniummill tailings should be considered (40 CFR 192). A decisionnot to fully employ such methods should be based on a demonstrationof significant differences between the quantity and attractivenessfor inappropriate uses of uranium mill tailings and watertreatment wastes. The disposal method should be augmented bylong-term institutional controls to avoid future misuse ofdisposal sites. Such institutional controls are not normallyalready in place at sanitary landfills.

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In general, dilution of these wastes to lower concentrationsto facilitate disposal should not be considered except where theradium concentration is in the lower end of the range (i.e. near50 pCi/g) to permit disposal as under paragraph 2 above.Very large volume increases should be avoided.

At concentrations approaching 2000 pCi/g, disposal of wasteswithin licensed low-level radioactive waste disposal facilitiesshould be considered.

4. Solid Wastes Containing 30 to 2,000 pCi/g (dry weight)Uranium or Lead-210

(a) The disposal method should be determined case-by-case.Disposal by standard municipal landfill practices may be consid-ered, provided that the radioactive solid wastes make up nomore than 10% of the total waste in a landfill and that groundwater will be adequately protected. At the high concentrationend of this range, disposal methods approved for hazardouswastes or uranium mill tailings may be needed, especially forlarge waste quantities. Also, at concentrations approaching2000 pCi/g, disposal of wastes within a licensed low-levelradioactive waste disposal facility should be considered.

(b) Alternatively, solid wastes may be mixed with othersolid materials to yield a product that qualifies for disposalaccording to the provisions of section 1 above.

(c) Recovery of the uranium resource should be consideredfor wastes containing greater than 300 pCi/g or 0.05 percent ofuranium.

5. Solid Wastes Containing More Than 2,000 pCi/g (dry)of Natural Radioactivity

Wastes with natural radioactivity concentrations exceeding2,000 pCi/g should be disposed of in a low-level radioactivewaste disposal facility operated under the provisions of theAtomic Energy Act, as amended.

6. Recordkeeping

Water treatment facilities should keep records of theamount and composition of radioactive wastes (solid and liquid)they generate and of the manner and location of their disposal.However, this guidline is not meant to cause an increasein Federal record keeping requirements for water treatmentfacilities.

a

I

Figure 2Guideline Sunmary For Solid Water Treatment Plant Wastes

Containing Natural Radioactivity

I SOLID WTP WASTES

[initial screeningl

, _ ___.v _ _______ __ _ I

* Land disposal requirements may apply: 40 CFR 257 and 260-266.

- 33 -I/

Recommended Radiation Exposure Limits for WorkersIn Water Treatment Facilities

In determining appropriate radiation exposure limits forwater treatment plant workers, there are a number of pertinentsources of guidance which can be used as a basis for recommenda-tions. In general, individuals in the United Stlates receivean average radiation dose of approximately 360 millirems peryear (mrem/yr) from natural and man-made radionuclides includingradon (40). The International Commission on RadiologicalProtection (ICRP) recommends that additional man-made exposureof members of the general public be limited to 100 mrem/yr,due to chronic exposure from all sources, excluding medicalexposure and background, and that no single source provide alarge fraction of this limit (41).

As this document provides recommendations for workers,more applicable is the Radiation Protection Guidance toFederal Agencies for Occupational Exposure," approved by thePresident in January of 1987. This guidance limits doses toworkers to an upper bound of 5,000 mrem/year and furtherrecommends that (a) doses be as low as reasonably achievable(ALARA), under this limit, and (b) doses not approach thelimit for substantial portions of a working lifetime (43).Under the recommendations of the Radiation Protection Guidance,administrative control levels which take into account ALARAmay be developed below the limiting values for specificcategories of workers or work situations.

Personnel in water treatment facilities removing naturallyoccurring radionuclides from drinking water may be exposed tohigher-than-background radiation levels. The doses thatthese workers would receive, however, as discussed in thenext section, are normally very much lower than the upperbounds for workers in radiation facilities. As there is noneed to allow these workers to receive radiation exposures upto the occupational limits, and since radiation exposuresshould be maintained as low as reasonably achievable, it isappropriate and feasible to limit these workers to exposurelimits much less than 5,000 mrem/yr.

Based on the radiation levels that treatment plant workersmay be exposed to and taking into account the recommendationsof the Radiation Protection Guidance for occupational exposureof workers, it appears a reasonable objective to keep treatmentplant workers' exposures to well within the levels recommendedfor the general public (i.e., 100 mrem/yr) with respect toman-made sources of radiation. An administrative controllevel of 25 mrem/yr would meet these objectives and is reasonablyachievable at water treatment plants.

In order to insure that workers who will be exposed tolevels of exposure above background have proper training andhave their exposures monitored as below the above limit, it

4

-34-

is necessary to identify radiation areas within the treatmentplant. Based on these requirements, it is suggested thatradiation measurements be made within the plant and thatareas which have radiation levels which could lead to workerexposures equal to or greater than the limit of 25 mrem/yrbe identified and posted as radiation areas. Individualsworking in radiation areas for a significant period of timeshould have their exposures assessed and receive propertraining.

In addition to direct radiation exposures, water treatmentplant workers can be exposed to radon gas. The occupationallimit for workers in uranium mines is 4 working level months(WLM) per year. Levels in water treatment plants will normallybe far below such levels. EPA has recommended that homeownerstake some action to reduce levels in their homes when yearlyaverages exceed 4 pCi/L (31). EPA's Standards for RemedialAction at Inactive Uranium Processing Sites require cleanupof buildings with the objective of reducing radon decayproducts to less than 0.02 working levels, or approximately4 pCi/L in air (32). Based on the ease of achieving low levelsfor drinking water treatment plant workers, a limit on radonlevels of 4 pCi/L is reasonable. Because of the differentconditions in work places, however, the times over which radonconcentration is averaged may be less than one year ifappropriate (chosen to correspond to normal working hours andconditions).

Sources of Radiation in Water Treatment Plants

Water treatment plant operators may be exposed toradiation other than background near the vicinity of mediavessels containing ion exchange resins, granular activatedcarbon, and sand filter beds. All of these media concentratethe radioactive contaminants to be removed from the water.Additional sources of radiation include radon gas fromstripping towers and aerator/reservoir basins.

Studies by Bennett concluded that radiation exposure tooperators, above background levels, at water treatment plantswhich remove radium would not typically exceed 25 to 100mrem/yr 42). A study conducted by EPA at the Elgin, Illinoiswater treatment plant found significantly higher radiationlevels near the sand surface of one pressure filter bed thatwas drained for service. However, the study concluded thatbecause no worker would be exposed for any great length oftime, such a situation would not pose an unacceptable hazard.Another study performed by the State of Wisconsin at a watertreatment plant in Elkhorn, Wisconsin, indicated that gammaradiation exposure levels near the ion exchange vessels werebarely detectable over background levels. Measurements atthe surfaces of settling tanks, along the bottom and top ofthe aerator/reservoir, along the sides of iron filters, andwithin the general plant area indicated that gamma radiationwas not detectable over background levels.

.1

-35-

Radiation levels higher than background may be encounteredin facilities that utilize exchange or adsorption media thathave a strong affinity to the contaminant to be removed. Anionexchange resins removing uranium, selective sorbents removingradium, and granular activated carbon (GAC) used to removeradon have the capability of accumulating relatively high levelsof radionuclides during their service life. Radiation measurementshave detected gamma radiation levels 2 to 5 times above backgroundlevels in the vicinity of GAC systems removing radon from drinkingwater (28). One recent study indicated that measured gammaradiation at the surface of GAC water treatment units, with influentradon at approximately 190,000 pCi/l, ranged from 1.8 to 16 mrem/hr(bottom and top of units, respectively)(4 5). Another reportindicates that an empirical relationship of 1.0 mrem/hr (maximumgamma on GAC vessel) per 10,360 pCi/l of influent radon was observed,based on measurements at 10 sites(46). It must be noted, however,that gamma radiation from a GAC unit treating for radon is signifi-cantly reduced within a few feet of the unit.

Personnel removing media from filter beds, ion exchangevessels, or handling sludges may be exposed to radiation abovebackground levels during the time the tasks are being performed.In addition to external exposures to radiation, radon gaswithin the water treatment facility can be a source of internalexposure to the lungs. Radon gas can build up to high concen-trations in poorly ventilated areas, although proper ventilationshould reduce levels to near background.

Exposure Guidelines

1. Routine Plant Operations

a. General radiation levels in areas of watertreatment plants removing radionuclides from drinking watershould be monitored at least yearly.

b. Radiation levels in the vicinity of componentsconcentrating radioactive materials should be monitored atleast quarterly.

c. Additional measurements should be performed ifthe component accumulating the radionuclide is replaced, ifthe process is changed, if the length of service is increased,or if significant increases of radionuclide concentrationlevels are experienced in the influent water.

d. Radiation exposure to personnel working in adrinking 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 wherean individual working in the area could receive a short-termexposure that would be a significant fraction of the above limit,such as 1 mrem/day, those locations should be designated asradiation areas and restricted to specified personnel.

f. Persons working in radiation areas should haveappropriate training and their radiation exposure monitoredthrough either area or personnel monitoring, as appropriate.

-36-

g. Radon levels in the air should be monitored andshould not exceed a yearly average of 4 pCi/L. Because ofshort-term conditions that may result in elevated exposures,such as during maintenance of treatment units, the time periodover which the radon concentrations are averaged may be chosento correspond to normal working hours and conditions.

h. Sludge storage sites, evaporation and drying lagoonsshould be fenced to prevent unauthorized intrusion.

2. Handling and Shipping Radioactive Wastes for Disposal

a. When removing and preparing wastes containingradionuclides for transportation and disposal, the task shouldbe evaluated to keep radiation exposures as low as reasonablyachievable. This may entail special training, tools, orshielding. In addition, personal protective equipment, suchas respirators and protective clothing, may be necessary toreduce exposures in some situation.

b. Granular activated carbon beds used to removeradon from water should be taken out of service and allowedto stand at least three weeks before the beds are replaced.This will allow time for decay of radon and short-liveddaughter products. This precaution will reduce radiation.exposure to the personnel handling the discarded GAC. Ifsystem constraints do not allow the unit to be removed fromservice for three weeks, alternative means should be used toreduce exposures from radon and its daughter products.

c. Only properly trained personnel should handleradioactive wastes.

d. Personnel handling radioactive wastes should havetheir radiation exposure monitored.

e. Total radiation exposure to personnel workingwithin water treatment plants, including handling the wastes,should not exceed 25 mrem/yr and should remain as far belowthat level as is reasonably achievable.

f. When shipping radioactive wastes, the appropriatelocal and State regulations should be followed.

g. When shipping radioactive materials whose concen-trations exceed 2,000 pCi/g, the appropriate Department ofTransportation standards must be followed as prescribed in49 CFR Parts 100 - 179.

h. Wastes containing uranium in excess of 0.05% byweight are considered source materials as defined in 10 CFRPart 40. Water treatment facilities producing, handling,disposing and transporting wastes containing uranium in excessof 0.05% by weight would have to obtain a license from the U.S.Nuclear Regulatory Commission, unless conditions defined in10 CFR 40 are met which exempt or preclude licensure(44).

-37-

References

1 National Primary Drinking Water Regulations. Federal Register.45(168):573257.

2 Management of Water treatment Sludge Containing Elevated Levelsof Radium. Illinois Department of Nuclear Safety. December,1984.

3 Interim Guidelines for the Disposal of Liquid and Solid WastesContaining Radium for Wisconsin Water Treatment Plants. WisconsinDepartment of Natural rescources, October, 1985.

4 Suggested State Regulations for Control of Radiation. Conferenceof Radiation Control Directors, 1982.

5 New Hampshire Rules for the Control of Radiation. State of NewHampshire, State Department of Health and Welfare, Concord, NH.,April, 1983.

6 Rules and Regulations Pertaining to Radiation Control. ColoradoDepartment of Health, 1978.

7 R.J. Schliekelman, Determination of Radium Removal Efficienciesin Iowa Water Supply Treatment Processes, Technical Note ORP/TAD-76-1, EPA. June, 1976.

8 Brinck, W.L. et.al, Radium Removal Efficiencies in Water TreatmentProcesses. JAWWA 70(l):31-35, 1978.

9 Manual of Treatment Techniques for Meeting the Interim PrimaryDrinking Water Regulstioms, EPA-600/8-77-005 May, 1977.

10 Lassovszky, P. and Hathaway, S., Treatment Technologies toRemove Radionuclides from Drinking Water. Preconference Reportfor 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 theRemoval of Radium from Potable Water Supplies. Report Preparedfor the U.S. Environmental Protection Agency, V.J. Ciccone andAssociates, Woodbridge, VA. August, 1983.

12 Bondietti, et.al. Methods of Removing Uranium from DrinkingWater: II Present Municipal Treatment and Potential TreatmentMethods. EPA-570/9-82-003, ORNL/EIS-194. December, 1982.

13 Hanson, S.W., Wilson, D.B., Gunaji, N.N., Removal of Uraniumfrom Drinking Water by Ion Exchange and Chemical Clarification.EPA/600/S2-87/076, Cincinnati, OH. December, 1987.

-38-

14 Ciccone, V.J. and Associates, Technologies and Costs for theRemoval of Uranium from Potable Water Supplies. ReportPrepared 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 ReverseOsmosis in Sarasota County, Florida, JAWWA, April, 1980.

16 Lauch, R.P. Removal of Radium from Drinking Water, a ResearchSummary. U.S. Environmental Protection Agency, WaterEngineering Research Laboratory, Cincinnati, Ohio.

17 Shelley, W.J., Removal of Radium from Water by DirectPrecipitation by a Soluble Barium Compound. Kerr-McGeeCorporation. Letter to George Reed, Director, Bureau ofWater Rescources, University of Oklahoma, April 1983.

18 Evaluation of Barium-Radium Coprecipitation as a TreatmentProcess 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 WaterSupplies. Journal of Environmental Engineering, Vol. III,No. 4, August, 1985.

20 Technologies and Costs for the Removal of Radon from PotableWater Supplies. Report Prepared for EPA by Malcolm Pirnie,Inc., Paramus, NJ. January, 1987.

21 Rozelle, R.E. et. al. Potable Water Radium Removal Update onTests in Missouri, Iowa, and Wyoming by the Dow Company.Internal Report, Dow Chemical Company, Midland, Michigan.

22 Rozelle, R.E., Ma, K.W., 1983. A New Potable Water Radium/RadonRemoval System. Paper presented at National AWWA Convention,Las Vegas, Nevada, June, 1983.

23 Snoeynk, V.L. et. al. Removal of Barium and Radium fromGroundwater. Environmental Research Brief. EPA/600/M-86/021.February, 1987.

24 Determination of Radium Removal Efficiencies in IllinoisWater Supply Treatment Processes. U.S. EPA Technical NoteORP/TAD-76-2. June, 1976.

25 Ciccone, V.J. and Assoc. Analysis of Occurrence, Controland/or Removal of Radionuclides in Small Drinking WaterSystems in Virginia. Report prepared for the U.S. EPA,Office of Drinking Water. Woodbridge, VA. September, 1987.

a

-39-

26 Disposal of Radium-Barium Sulfate Sludge from a Water TreatmentPlant in Midland, South Dakota. A technical assistanceprogram 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 CarbonAbsorbtion. Maine Department of Human Services, Division ofHealth Engineering, September, 1986.

28 Memorandum from Thomas Sorg, EPA, WERL.

29 Ore tining and Dressing Point Source Category EffluentLimitations 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 U.S. Environmental Protection Agency and U.S. Department ofHealth and Human Services, "A Citizens Guide to Radon: WhatIt Is and What to Do About It", OPA-86-004, U.S. GovernmentPrinting Office, Washington, D.C. August, 1986.

32 U.S. Environmental Protection Agency, Health and EnvironmentalStandards for Uranium and Thorium Mill Tailings, 40 CFR 192.Preamble for inactive sites -- 40 CFR 192, January 5, 1983;for active sites -- 40 CFR 192, October 7, 1983.

33 U.S. Nuclear Regulatory Commission, Disposal or Onsite Storageof Thorium or Uranium Wastes from Past Operations, 46 FR 52061,October 23, 1981.

34 U.S. Environmental Protection Agency, Advance Notice ofProposed Rulemaking, Environmental Radiation ProtectionStandards for Low-Level Radioactive Waste Disposal, 48 FR 39563,August 31, 1983.

35 Final Environmental Impact Statement for Remedial Action Standardsfor Inactive Uranium Processing Sites (40 CFR 192), Chapters 3and 4, Environmental Protection Agency 520/4-82-013-1, October1982; and Health Physics, Vol. 45, No. 2, August, 1983.

36 U.S. Environmental Protection Agency, FEIS for Standards forthe Control of Byproduct Materials from Uranium Ore Processing,EPA 520/1-83-008-1, September, 1983.

37 National Council on Radiation Protection and Measurements:National Background Radiation in the United States. NCRPReport No. 45, Nov. 1975.

.

- 40 -

.38 Kocher, D.C., Dose Rate Conversion Factors for ExternalExposure to Photon and Electron Radiation from RadionuclidesOccurring in Routine Release from Nuclear Fuel Cycle Facilities.Health Physics Vol. 38, No. 4. April, 1980.

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 RadiationProtection, ICRP Publication 26. January, 1977.

42 Bennett, D.L. The Efficiency of Water Treatment Processes inRadium Removal. JAWWA. December, 1978.

43 U.S. Environmental Protection Agency, Radiation ProtectionGuidance to Federal Agencies for Occupational Exposure:Recommendations Approved by the President. Washington, D.C.1987.

44 Domestic Licensing of Source Material, 10 CFR part 40, FederalRegister, March 29, 1985.

45 Kinner, N.E. et al. Radon Removal From Drinking Water UsingGranular Activated Carbon, Packed Tower Aeration and DiffusedBubble Aeration Techniques. Presented at 1988 Symposium onRadon and Radon Reduction Technology, Denver, CO. October17-21, 1988.

46 Lowry, J.D. et al. New Developments and Considerations forRadon Removal From Water Supplies. Presented at 1988 Symposiumon Radon and Radon Reduction Technology, Denver, CO. October17-21, 1988.

S -

a

< * ¾-' -41

GLOSSARY

Alpha radiation - A helium nucleus, two protons and two neutronsemitted from the nucleus.

Beta radiation - An electron emitted from the nucleus as aresult of neutron decay.

Curie - The activity of one gram of radium, or 3.7 x 1010disintegrations per second.

Daughter - The isotope resulting from radioactive decay.

Dose - Quantity of radiation absorbed, per unit mass, bythe body or by any portion of the body.

Gamma radiation - A form of electromagnetic radiation. Gammadecay will not result in a formation of a new isotope.

GAC - granular activated carbon: a medium useful in treatmentof 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 todecay.

Isotope - Varieties of the same element with different masses.

Ionizing radiation - Radiation that is capable of ionizing orremoving one or more electrons from an atom.

Licensed Material - Source material, special nuclear material,or by-product material received, posessed, used or transferredunder a general or specific license issued by the U.S. NuclearRegulatory Commission.

Natural radioactive series - Sequence of elements that existnaturally and decay in a serial fashion.

Parent - The isotope that undergoes radioactive (alpha orbeta) decay, resulting in a daughter product.

Quality factor () - A factor that roughly approximatesthe relative differential damage that ionizing radiation cando to tissue. For beta particles and all electromagneticradiations (gamma rays and x-rays), 0 = 1. For neutronsfrom spontaneous fission and protons, Q = 10. For alphaparticles and fission fragments, 0 = 20.

Rad - A measure of dose of any ionizing radiation to bodytissues in terms of the energy absorbed per unit mass oftissue. One rad is the dose corresponding to the absorbtionof 100 ergs per gram of tissue.

J6

-42-

Radioactive decay - A process where the nucleus transforms to alower energy state by emitting alpha, beta or gamma radiation.

Rem (Radiation Equivalent Man) - A measure of the dose ofany ionizing radiation to body tissues in terms of its estimatedbiological effect. This term is more descriptive of the actualdamage done to tissues from ionizing radiation. The number ofrems is expressed in terms of a quality factor times the numberof rads. One Millirem (mrem) is one one-thousanth of a rem, or10-3 rem.

Source material - Uranium or thorium in any combinationthereof, in any physical or chemical form or materialsthat contain by weight 0.05% or more uranium, or thoriumor any combination of these two substances.

Working Level(WL) and Working Level Month(WLM) - Any combinationof short-lived radon daughters (through Po-214) per liter of airthat will result in the emission of 1.3E+05 MeV of alpha energy.An activity concentration of 100 picocuries per liter of Rn-222in equilibrium with its daughters corresponds approximately toone WL. A working level month(WLM) is an exposure to a concen-tration of one WL for 170 hours (about 21 work days).

v~~~K-43-

APPENDIX

Estimated Radioactivity and Quantity of Water A-1Treatment Waste Residues

Radium Concentrations in Lime Softening Wastes and A-2Ion Exchange Wastes, 3 Tables

Results of Sarasota Co., Florida, A-3Reverse Osmosis Radium-226 Removal Sampling

EPA Uranium Removal Field Study A-4

Radium Originating from Drinking Water A-5in Wastewater Treatment Plant Sludges

Pb 210 Build-up in GAC Filter A-6

Farmland Application of Fertilizers A-7Containing Natural and AcceleratorProduced Radioac-ive Materials

Sources of Radiation for People in A-8the United States

Range of Nuclear Particles with the A-9Same Energy

Natural Radioactive Decay Series A-10

Engineering Shorthand and Greek Prefixes A-13

Standards for Uranium ill Tailings A-14

9

TABLE 5-I

ESTI&TED MDIMCTIVITt AND QUANTITt o WATER TREAENT WASTE RESIDUES

Raiemtivity Levels a a Function of Quantity of Waste Stream as a Function ofResidue tAlomativlt, of Raw Water, pCI/I TDS of Raw Water, R/I

15 30 50 400 1,000 2,000

Lime-Soda 4.80020.500 6,900-34,100 10,500-51,400 1.800- 3.200 3,100- 6.500 7,600-16.200Softenng(1) pCi/lbs Dry pCi/lbe Dry pCi/lbs Dry Dry lbs/C Dry bs/tIC Dry lbs/KCSludge Sludge Sludge Sludge

Lime-Soda 40-60 130-1S0 245-265 20,000-40.000 20,000- 40.000 20.000-bO.000)*ackwash Water pci/gal pCi/gal pCI/plI Callons/NC Gallons/C Gallons/C

Ion-Exchange 490-2.460 1,140-6,060 2,270-11.360 15,000 gal/"C 30.000 gal/"C 7S.000 gal/NCRegeneration pCI/gal pCi/gal pci/galBrine

Reverse Ososis 280-760 4SLI,020 750-1.1190 60.000 al/"C 60.000-100.000 160,000-260.000)Reject Water pcit/gal pCi/gal pCI/gal gal/KG gal/m;

(1) Wet lime soda softening sludges have been reported to contain between 2 to IS percent solids. After extended lmriolsof storage In a landfill or impoundment, 10 percent solids or greater have been reported. Values reported Isere ordry solids my be converted to values for vet sludge of different percent solids by ultiplying by tle appropriateconversion factor.

(

.

(

source: EPA 60012-77-073. Costs of Radium Removal from Potable Water Supplies.

A-2

SUMMARY OF RADIUH CONCENTRATIONS IN LESOFTENING SLUDGES AND BACKWASH WATERS

Ka226 Ca225 1a226 Ca228

LOCATION S Soli s (DOCi/0 (oCi/l) DCi/a(dryv) Ci(dry)

w. Oes oines. IA(raw water Ra-226, 9.3.pCi/l)Lagoon Sludge 37.6 S,150 S96 10.6 1.3Clarifier Sludge 1.6 t2O '40 *.02 .0Lagoon Sludge NA 2,300 NA NA NABackwash Water NA 6.3 NA NA NA

BushnelI. IL

Clarifier Sudge 19 4,577 (45 21.6 21

Colchester. IL

Clarifier Sludge 12.6 2,038 236 15.0 1.7lackwash Water 0.23 <20 <39 NA NA

Webster City. IA

(raw water Ra-226, 6.1 pCi/1)Sludge VA 980 NA NA NABackwash ater NA so NA NA NA

Peru L .

(raw water Ra-226, 5.8 pCi/l)*ackwash Water NA 36.9 NA NA NA

Eluin. It

(raw water Ra-226, 5.6 pCi/l)Active Lagoon Sludge s.3 9,642 9.939 11.3 11.7Inactive Lagoon Sludge 67.1 11.686 12,16? 10.9 11.3Clarifier Sludge 10.3 946 573 5.6 8.0lackwash ater 0.051 *20 '40 c.02 '.04Sludge* NA 6,100 NA NA NAlackwash ater NA 16.3 NA NA NA

Assume specific gravity a 1.0

source~noeyink, VL., et al., "Characteristics and Handling ofWastes from Groundwater Treatment Systems," Sunday Seminaron Experiences with Groundwater Contamination, AWWA NationalConference (1984).

A-2aK'~

2Ra2 2 6 CONCENTRATIONS IN ION EXCHANGE,TREATMENT PLANT WASTEWATER

LOCATION

Average

Brine + Rinse

(DCi/0)

530

Average

Brine Rinse

+ Backwash

00Ci/ I)

420

Average

for Peak

1/4 1/3 of

Regeneration

Cygle oCi/I)

2,000

Peak

Concentration

in Wastewater

DCi C/l)

Raw Water

Concentration

(oCill)

Eldon, IA 3,500

Estherville, IA

Grinnelt, IA

Nolstein, 1A

NA

110

175

52

NA

NA

114

260

576

320 5

320 6

1,100 13

Source: SchieetelanDetermination of Radium Removal Efficienciesin Illinois Water Supply Treatment Processes.EPA Technical Note, ORP/TAD-76-2 (June 1976).

-f A

A-2b

RADIUM CONCENTRATIONS INFILTER MEDIA AND SOFTENER RESINS

LOCATION FILTER/MEDIATYPE

CONCENTRATIONS MEASURED(PCi/g)

Ra-226 Ra-225

Herscher, IL* Iron Filter 111.6 38.9Zeolite Softener 43 15

Lynwood, IL** Zeolite Softener 9.6 6.6

Dwight Correct. Natural Greensand 28-46 59Center, IL

*after 10 yrs. operation*after 2 yrs. operationSource: Bennett, D.L. The Efficiency of Water Treatment

Processes in Radium Removal. JAWWA (December 1978).

A-3

RESULTS OF SARASOTA 00., FLORIDA, REVERSE OSlmOSISRADIUM-226 RM>VAL SAMPLINGt

System Raw Water Raw WaterTDS Ra-226

(Mg/1) (pci/i)

Product Water Ra-226 Reject PercentRa-226 Removal Water Water

(pCi/i) Efficiency Ra-226 Rejected(M) (nCi/1) (%)

SystemCapacity(1000GPD)

Bay Lakes~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Bay LakesEstates kMHP

Venice

Sorrento Shores

Spanish LakesMP

Nokomis School

Bayfront TP

Kings Gate TP

Sarasota BayMHP

2,532

2,412

3,373

1,327

1,442

895

1,620

2,430

3.2

3.4

4.6

10.4

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 93%

40

"h.

7.8

7.9

20.5

11.9

19.4

37.9

46

61

69

72

50

1000

200

70

11.1

12.1

15.7

20.5

0.8

1.6

30

5

(.

tSorg, T.J., et al., JAWWM. April, 1980.

.9 4

A- 4

EPA URANIUM REMOVAL FIELD STUDY(ANION EXCHANGE)

Unit Raw Water Treated Water* Gallonst* BedLocation Uranium Uranium Treated Capacity

(ug/1) (ug/1) (lb Uranium/ft3 )

Ft. Lupton, CO 35. 35. 22,310t* 0.007

Brighton, CO 23. 23. 45,460t* 0.009

Marshdale, CO 28. <0.1 40,610 ---

Cove, AZ 64. 63. 31,400t* 0.017

Church Rock, NM 52. 0.1 20,360 ---

* 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

4A-5

Plaium oricinatiro fra drirkini aterin tater treatrwnt pnt sludges

Louation Source Refs-&,--,-

Sludge frt %astewater plantFord du Lac Wisc.

Cigestei SludeJuneau Wiscorsin

Diestei sludgeLake Mil.s, Wisconin

uster supply31.9958

GrissGr s

Bakash ironfock fr= WLtreaue~nt plant

70.9692

Or sGrw s

Eci/qpCi/Lalphabeta

pCi/qalphabeta

pCl/cpCi/Lalphabeta

dry wt3% solids76.9 i/q83.9 pCi/g

3.3% solids119.6 pCL/g96.8 pCi/q

dry t4.2% olija

100.8 pCi/g79.8 pCi/c

I

I

ICa'niity. ater suMly

31.91565

OrmsSGres s

Digest sludgeColby, Wiscorsin

Ion Exdh. ^ nerationand badcash frcm DWtrneatnt plant

38.5 :i/q 1157 pi/LGrs alphaGrins beta

fry t3% so Lids *184.0 pCi/q1R. 5 i/q

I

Corerqatian tSt gnes, Wisecmin

lon Exch. Renerationard badcash frm Wtreatmnt plant

24.9 - 38.S pCi/q dry wt7SO - 1157 pCi/L 3% olids

Grwss alpha 184.o-3e2.4 pCi/qGriss beta 188.S-389.2 pCi/q

1 Source: Radoactivity n tMnicipl Slugle EP Draft Raprt Of flce ofrater Rqulatiors and Starmarois.

O S

a

4,

50000

40000Influent RnConcent rat lon

Cn_

De

C' 30000CD

°

Cm 20000T-ICU

-

GIVEN 1O0OL/DAYGAC 957. Eff.Pb 0.05. of Rn

A. . ... .. .. . . 0

200K pCt/L

C

as

0 3 6. 9 12

MONTHSLead 210 build-up in GPC Rn removal

tfilter

Source: Sorg, T.J., 1988

.

Farmland APPl ication of Fertil izers Containinq Natural and AcceleratorProduiced Radioactive Materials

I Qeantity gneratedStree per year Specific Chemical/ Nonmrdin-type of activity, physical logical Present

Wante nurIiden I tw0 Kg CI PC'l form, RCKA hasarda "ean* of dposel Coments

A-I1-SI3-9-i5-10-5

Po-210P4-yINPP-2n

14I )I I

None Applied toefrmland. (

AlrIculturalPhn"pholypra"M

PI-22611-238

6^0 1l3.2

2800

24 Soltd14.6 grind

700 Solid

.

potash

None Applied tofarmland.

None Applied tofarmland.

Uncalcined phoaphogypsumfor agricultural purposea.Nuclide ctivities areboed on caicined phocpho-gypsum data.

Potaeh application varieswith oil characteristicsand crop needa.

4070(KiOequiw-alent)

norl Super-Fhoaphate

Triple Super-Phosphate

Ammonium Posphates

Pa-22616-238Ti-210Th-232

315 766

0.2

262210

0.6

2120200.6

11-238Th-210TA-226Th-212

5749211.3

58576

Liquid

Liquid

None Applied tofarmland.

None Applied tofarmland.

None Applied tofarmland.

Fertilizer pplicatlonrange i approamately 30kg POS/hiectore for barley,wheat, and oats and 150 kgP205/hoctare for potatoea.

The quantity of fertiliecrproduced i bed on 1983P205 date for fertilizerproduction and 201 205In ertilizer.

The quantity of fertilizerproduced I based on 1983'20 s data for fertilizerproduction and 471 ?20SIn fertilizer.

The uantity of fertilizerproduced t based on 1913P2°5 data for phosphoricacid production, one-thirdof which to used to produceaamoiu posphate.a end452 20 In fertilizer.

C

U-238Th- 230Ra-226Th-232

3983914121

Z

A-8

Sources of Radiation and Exposure to U.S. Population*

Exposure(mrem/yr)

Natural Background Radiation

Cosmic (protons,muons,high energy e)Cosmogenic (H-3, C-14, B-7)Terrestrial (Ur Th, Ra, K-40)Internal (K-40, Po-210Inhaled (Radon and progeny)

Subtotal

2712839

200300u

Man-made Radiation

includes: medical x-raysnuclear medicineconsumer productsother(occupational, falloutnuclear fuel cycle, misc.)

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Total Exposure= 360 mrem/yr

* from National Council for Radiation Protection and Measurements,Report #93, September 1, 1987.

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Standards for Uranium Mill Tailings (40 CFR 192)

Uranium Mill Tailings contain uranium series radioactiveelements, including radium, and toxic nonradioactive hazardoussubstances, such as molybdenum and selenium. The radiumconcentrations vary from about one hundred to a few thousandpCi/g. The major risk pathways are:

o Diffusion of radon-222 (produced by radium-226) intoindoor air, either directly from a tailings pile orwhere tailings were used in construction. Breathingdecay products of radon can cause lung cancer.

o Direct gamma radiation exposure.

o Dispersal of small particles of tailings material inthe air.

o Waterborne transport of radioactive or nonradioactivetoxic materials.

The major goals of the standards are twofold: (1) Tostabilize tailings piles so as to minimize their emissions andthe potential for human misuse of tailings, and (2) to remediateexisting and potential hazards posed by tailings that nature orpeople have removed from the piles.

Objectives of the standards are summarized morespecifically below. (This is simplified paraphrasing: see40 CR 192 for the exact requirements.)

For Tailings Piles (disposal)

The standards require reasonable assurance of control ofradiological and non-radiological hazards to be

o effective for 1000 years, to the extent reasonablyacheivable, and, in any case, for at least 2000 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 watertable, these conditions may all be satisfied by a liner andthick enough durable cover that is designed to keep radon in andwater out. Importantly, such covers are significant barriers to

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inhibit access for misuse. The standard must be satisfied byphysical means wnose long-term effectiveness does not depend oninstitutional control. The Uranium Mill Tailings RadiationControl Act, which authorized these standards, provides theimportant additional protection of government ownership ofdisposal sites.

Cleanup of Buildings

Tailings have been used in building materials and underbuildings. Radon from these tailings accumulates indoors wherepeople spend most of their time.

O For bildings affected by tailings, take allreasonable measures to reduce indoor radioactivity to0.02 L, primarily by removing the tailings, and thegamma radiation to less than 20 uR/hr above background.

This not only reduces hazards in existing buildings butwould avoid perpetuating the hazard in future replacementbuildings.

Cleanup of Land

Tailings have been removed from piles and deposited on openland by either weathering or deliberate human actions.Weathering tends to disperse tailings in thin layers at lowconcentrations. Human removals, even where tailings were mixedwith other materials, tend to be of bulk materials and to retainhigh concentration.

o Remove tailings deposits from open land if they aregreater than 5 pCi/g within the top 15 cal, or greaterthan 15 pCi/g below.

The objectives are to avoid future hazards from building onsuch land, and to remedy any current unnecessary exposures.Note that the concentration of displaced tailings generallyvaries from their high original concentration of many hundredsof pCi/g to values approaching background (approx. 1 pCi/g).This variation occurs gradually for weathered material, andabruptly at the edges of bulk removals. Therefore, any tailingsnot cleaned up under the standard will generally be no more thanthin deposits, not bulk masses, that are below the concentrationlimits.

The residual hazards will generally be much less than wouldbe expected from ulk material deposits with concentrations atthe cleanup limits. These cleanup standards are designed toreduce the potential hazard from an existing undesirable

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