34056 Federal Register I Vol. 51, No. 185 I Wednesday, September 24, 1986 I Rules and Regulations 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 61 

[ Ao-fR-3060-7) 

National ~mission Standards for · 

Hazardous Air PoHutant8 (NESHAP&); 

Standards for Radon-222 Emlsslorla 

From Ucenaed Uranium MHI TaiRnga 

AGENCY: Environmental Protection 

Agency (EPA). · 

ACTION: Final rule. 

SUM.MARV: This final rule establishes 

work practices that apply to tailings at 

licensed uranium mill sites. Radon-222 is 

emitted from these tailings in amounts 

sufficient to produce a risk to public 

health. The work practices established 

here will limit the emissions of'radon· 

222 in accordance with Section 112 of 

the Clean Air Act. 

EFFECTIVE DATE: The final rule is 

effective on September 24, 1986. 

ADDRESSEES: The rulemaking record Is 

contained in Docket No. A-79-11. This 

docket is available for public uispection 

between 8:00a.m. and 4:00 p.m .• ~onday 

through Friday, at EPA's Central Docket 

Section. West Tow~r .Lobby. Gallery . 

·One. Waterside_ Mall, 401 M Street, SW., 

Washington, DC 20480. A reasonable fee 

may be charged for copying. 

FOR FUJmtER INFOAMAT10H COHTACT: 

Terrence A. McLaughlin, Chief. 

Environmental Standards Branch. 

Criteria and Standards Division (ANR460). Office of Radiation Programs, U.S. 

Environmental Protection Agency, 

Washington, DC 20480, {Z02) 475-0010. 

SUPPL£MEHTARY INFORMATION: 

1. Supporting Documents 

The draft background information 

document and draft economic analysis 

issued in support of the proposed rule 

have been revised in response to public 

comments and are now issued in final 

form titled. respectively. "Background 

Information Document-Final Rule for 

Radon-222 Emissions from Licensed 

Uranium Mill Tailings" (EPA 520/1-a&-

009) and "Economic Analysis-Final 

Rule for Radon-222 Emissions from 

Licensed Uranium Mill Tailings" (EPA 

520/1-86-010). 

. The documents contain projections of 

radon emissions and the resulting risks 

to nearby Individuals and to populations 

due to the operation of the uranium 

milling industry, a description of radon 

control technology and associated costs, 

and an environmel)tal and economic 

analysis of the effects of alternative 

control strategies on the industry. 

In addition. the Agency's summary of 

public comments on the proposed rule, 

together with Ute Agency's reply to 

these comments. are contained in the 

document "Response to CommentsFinal Rule for Radon-222 Emissions from 

Licensed Uranium Mill Tailings;, (EPA 

520/1-a&-011). 

·single copies of these documents may 

be obtained from the Program 

Management Office (ANR-459), Office 

of Radiation Programs. Environmental 

Protection Agency, Washington. DC 

20460, (202) 475-8386. 

11. Basic Temu Used in the Notice 

Defmitions of basic terms used in this 

notice are given below: 

1. ALARA-A practice in radiation · 

protection that encourages radionuclide 

emissions to be kept "as low as 

reasonably achievable." 

2. Continuous disposal-A method of 

tailings management and disposal in 

which tailings are dewatered by 

mechanical methods soon after 

generation. The dried tailings are then 

placed in trenches or other disposal 

areas and immediately covered. 

3. Covered-Disposal of tailings in 

accordance with specifications required 

by. regulations appearing at 40 CFR Part 

192 and issued under the Uranium Mill 

Tailings Radiation Control Act 

(UMTRCA). 

4. Mill tailings-The waste resulting 

from conventional milling of uranium 

ore. Tailings are classified as either 

sands or slimes depending on particle 

size. Processing 1 ton of ore produces 

approximately 1 ton of tailings. 

5. Phased disposal-A method of 

tailings management and disposal that 

uses a series of small impoundments. 

Taillrigs are pumped to one 

impoundment until it is filled and then 

pumped to the next Impoundment. The 

filled impoundment is actively 

dewatered. or allowed to dry naturally. 

and ~en Immediately reclaimed. 

6. Radon-Radon-222; an inert 

radioactive gas. 

1. Radon decay proclucts-The seven 

principal radionuclides that are 

produced as radon-222 decays to 

nonradioactive lead. Radon-222 shortlived decay products means the four 

radionuclides with half-lives less than 

20 minutes produced as radon-222 

decays to lead-210 . 

8. Single cell disposal-A method of 

tailings management that. uses a large 

impoundment designed to contain all 

tailings generated during the lifetime of 

the mill. At the end of the mill life the 

impoundment is actively dewatered or 

allowed to dry and ls then immediately 

reclaimed. 

9. Tail/ngs pile-The on-site waste 

impoundment in which 'tailings are 

deposited. 

m. Background 

A. Industry Description 

Uranium milling involves the handling 

of large quantities of ore containing 

uranium and its decay products. In this 

ore, the .concentration of uranium and its 

decay products is about one thousand 

times greater than in other rocks and 

soils. Uranium milling recovers the 

uranium In the ore by mechanical and 

chemical processes that generate waste 

tailings. The ore is first crushed, 

blended. and ground to the proper siz!! 

for the leaching process, which extracts 

uranium. Several leaching processes are 

used, including the use of acid. alkali. 

and a combination of the two. After 

uranium is leached from the ore. it ia 

concentrated from the leach~te through 

ion exchange or solvent extraction. The 

concentrated uranium is then extracted 

from the concentrating medium. · 

precipitated. dried. and packaged. The 

depleted ore. in the form of tailings, is 

pumped to a tailings pile aa a slurry. 

Since ore generally contains less than 

0.5 percent uranium by weight, every ton 

of ore processed results in almost a ton 

of tailings. The tailings contain virtually 

aU of the uranium decay products 

present in the ore. including thorium-230 

and radium-226. which decay to radon. 

Previous risk analyses have shown that 

radon presents the highest risk of any 

radionucUde released to air at uranium 

mills and that the tailings pile is the 

most significant source of radon. 

The 26 licensed uranium mills In the 

United States are located in Colorado, 

New Mexico, South Dakota, Texas. 

Utah. Washington. and Wyoming. In 

addition, four mills have been licensed 

but not built. The milling industry is 

depressed due to a decline in the 

demand for uranium and competition 

from low-coat foreign sources. Three 

mills are actively processing ore, 17 are 

on.standby and could process ore in the 

future if market conditions improve, and 

6 are being decommissioned and will no 

longer process ore. The 20 licensed mills 

that are actively processing ore or on 

standby were considered in the 

analyses reported iri the supporting 

documentation. These ZO mills have 

about 35 tailings impoundments 

associated with them. Recently, three of 

theae mills have indicated to the NRC 

that they will no longer process ore and 

intend to reclaim the sites. 

Past milling activities have generated 

about 200 million tons or tailings. . 

Production at conventional mills peaked 
Fecleral Register I Vol. ·st. No. 185 I Wednesday, Septembe~ 24, 1986 I Rules. and Regulations 34057 

in i980. when 2l·mllla recovered more 

than 17 thousand tons of W'8nium and 

generated more thaD 14 miUion tons of 

tailinga. The induatry fa currently 

operatins at about 10 peroent of 

capadty due to the depressed market 

At this level of production. the lndu.try 

fa recoverins about 1.8 thouaarid tons of 

uranium and generating about 1.4 

million tons of new taillnp annually. ·At 

full capacity, the industry could generate 

approximately 14 million tons of taillilga 

a year. 

B. Estimates of Exposure and Risk 

Exposure estimates are based on 

radon emJaalons from tailings plies, 

since emiaalona and riakt from other 

parta of a uranium mill are .amall tn 

comparison. Radon emiaalon rate . estimates are baaed on the radlum-2Z8 

concentration In the tailings uaing the 

relationship of 1 picocurie of radon 

emitted per square meter per second for 

each picocurie of radium-226 per gram of 

tailings. II ia aasumed that the radium· 

2Z8 is evenly mixed throughout the 

tailings and that radon is emitted from 

all dry exposed surfaces of taillnp. The 

radium-2Z8 content of the taillll8S ia 

derived from the relationship of onetenth of one percent of uranium in ore 

equalllns 280 plcocuriea of radium-226 

per gram of ore and the a11umption that 

all the radium·2Z8 in the ore finds its 

way into the tailinp pile. 

aa appropriate. It I~ expressed In terms 

of annual number of fatal cancer cases 

and provides a measure of the overall 

impact on public health. For example, a 

total population impact of 0.5 fatal ~ncer cases per year me'"'s that 

emiuions of the specific pollutant are 

predicted to cause one case of cancer· every z years. As distance from a source 

iilcreaaea, risks to specific persona decre~ae and become extremely emaU: 

but, considering the total population 

exposed, the sums of these risks may be 

significant.· 

The two estimates together provide a 

better description of the magnitude and 

distribution of risk than either number 

alone. "Nearby individual riak" gi.vea an 

estimate of the highest ris.k, but not how 

many people may bear that risk. "Total 

population impact" describes the overall 

estimated health impact on tJ!e entire 

exposed population, but not how much 

riik the moat exposed persona may bear. 

For example, two sources of · radionuclide or chemical emissions 

could have similar population impacta 

but very .different maximum individual 

risks. or vice versa. Both estimates are 

important and both are used In mald.ng 

risk management decisions. The risk 

estimatea should not be viewed as 

precise determinations of likely health 

damage, but rather as a general 

indication of estimated health risk. 

EPA's analysis of n.ks·due to radon 

Standard meteorological transport 

modela are uaed to estlmat.e radon . concentrations in air at varioua 

_ emlsa.lons &om existing uranium tailings 

piles concluded: 

1. Lung cancer, which Ia caused by the. short-lived decay products of radon. fa 

the dominant health hazard from 

tailings. Estimated effects of gamma 

radiation and of long-lived decay 

products of radon are leas significant, 

although high gamma racijation 

distances &om the plies. Exposure to 

radon decay producte Ia then eatiDiated 

from the radon concentration In air. The 

final risk estimates are a .,roduct of the 

units of radon decay product exposure 

levela and a risk factor that relates risk 

to a single unit of exposure. 

Two meaaures of human exposure are 

of particular" Interest: "nearby individual 

risk" and "total population impact". The 

former refers to the estimated Increased 

lifetime risk to Individuals wlio spend 

their entire life at the location of existing 

residences where predicted 

concentrations of the pollutant are 

highest Nearby Individual risk Ia 

expressed aa a probability: for example, 

a risk of one in one thousand meant that 

a person spending hit lifetime at the . point of maximum exposure has an 

estimated increased risk of ohe in one 

thou1and qf developing a fatal ·cancer. 

Estimates of nearby Individual risk are 

best e1timate1, and are not upper bound 

estimates. · · · The second measure, "total 

population impact", consider& people e~oaed at all concentrations, low as 

well as high, and It considers people 

exposed throughout the United States, 

exposures may sometimes occur. 

2. Individuals living near an 

uncontrolled tailings pile are subject to 

high risks due to radon emitted from · tailings. Radon contained in th.e ambient 

air enters homes and other structures 

built near the mill through doors and 

.other openings In the structure. The 

resulting radon decay products tend to 

concentrate indoors, .thus exposing the 

occupants to potentially harmful levels . ofthe.ae radioriuclidea. The EPA 

estimates that. at present. some persona 

may' be exposed to rlib that are as high 

as one in one hundred. This estimate ia 

baied on median risk estimates and an 

assumed exposure of 70-years during 

which emission levels remain the same 

as present values. Of course, this time 

period is lo1J8er than aaaunied in EPA's 

"40-year'' analysis. Using the 40-year 

analysis, an exposure poains this .level 

of risk could only occur if an individual . remained at that location for the full 70-

year period, and the pile presenting that· risk was replaced after cloaura by 

another pile preaentfns tlie same risk 

factors. 

3. Based on models for the risk to all 

exposed populations (local. regional, 

and national), about one to five fatal 

cancers per year are e$timated from 

emi11iona ofradon from tailings .at the 

20 mill sites being considered here. if no 

controls are present. If the tailings at all 

sites were to dry out, it is eafunated that 

the risk could rise to about two to nine 

fatal cancers per year. However, not aU 

of the. piles are expected to dry out at 

the same time. Approximately one half 

of these deaths are estimated to occur 

within 80 kilometers of the taili1J8a piles. 

There Is substantial uncertainty In 

these eatlmatea because of uncertainties 

In the emission rates of radon from 

tailings sites, In the exposure people will 

receive from its decay products, and 

from Incomplete knowledge of the 

effects on people due to these . exposures. The values presented here 

represent beat estimates baaed on 

current knowledge. Examples of factor& 

leadill8 to possible underestimation of 

risk Include: the uae.of median rather. than upper. bound risk factors, ignori1J8 

radon sources at a mill aite other than 

the taillnge pile, and not considering 

piles where owners have Indicated · Intent to reclaim their pile but have not 

done eo for lo1J8 periods. Risks could be· overestimated if owners reclaim piles 

faster than EPA assumes, lfradon 

emissions are smaller due to leas .. radlum-Z261n a pile than is estimated, or 

If the radon emanation rate is lower 

than EPA eatj.matealt to be. 

Additionally, s.ince tb,eae estimates are 

baaed on current pile sizes and 

populatlbn distributions, as nearby 

populations increase or decrease in the 

future. the eatimated'impacta would · vary.lf specific information indicates 

radon emissions rates were lower, then 

risk estimates could be 19wer. 

·In general, much more is known about 

the risks from exposure to radiation 

than exposure to most chemicals. While 

there Ia uncertainty In risk estimates 

from a81essmenta of chemical emi11ions 

and radlonuclide emissions, there ia 

much less uncertainty In estimates of 

risk from radionuclide emissions 

because of the extensive data base on 

the effects of human exposure to 

radiation. Therefore. a risk estimate : . resulting from exposure to radionuclides 

l1likely to be more accurate than the . aame estimate for chemical exposures. 

C. History of Standard Development 

The Agency's .standards for Nuclear 

Power Operation (40 CFR Part 190) 
34058 Federal Register I Vol. 51, No: 185 I Wednesday, September 24, 1986 f Rules and Regulatiqns 

Issued under the Atomic Energy Ac1 (4Z 

FR 2858 (January 13, 1977)) limit the total 

individual radiation dose caused by 

emissions from facilities that make up 

the uranium fuel cycle, including 

licensed uranium mills. However. when 

40 CFR Part t90.was promulgated, 

considerable uncertainty existed about 

the public health Impact of existing 

levels of radon in the air. as well as · uncertainty about the best method for 

management of new man-made sources 

of radon. The EPA exempted radon from 

coverage under 40 CFR Part 190 since 

the problems associated with emission• 

of this radionuclide were sufficiently 

different from those of other radioactive 

materials associated with the fuel cycle 

to warrant separate cons!deratlon. 

EPA has. also Issued standards (48 FR 

459Z6 (October 7, 1983)) for uranium and 

thorium mill tailings at commercial 

processing licensed sites under the 

Uranium Mill Tailings Radiation Control 

Act of 1978 (UMTRCA}, which amwnds 

the Atomic Energy Act (AEA}. These 

standards for disposal of tailings require 

stabilization of tailings on final disposal 

so that the associated health hazards 

will be controlled and limited for 1000 

years to the extent reasonably 

achievable, In any case, for at least ZOO 

years. The standards limit releases of 

radon to the air after disposal, and 

require measures to limit releases of 

radionuclides and other hazardous 

substances to water {40 CFR Part 192., 

Subparts D and E). In the preamble to 

these standards. the Agency'diacussed 

the relationship between UMTRCA and 

the Clean Air Act (CAAJ and indicated 

its Intent to publish an Advanced Notice 

of Proposed Rulemaking (ANPR) to 

consider additional control of radon 

emissions during the operational phase 

of mills. 

Section ~zz of the CAA required EPA 

to determine whether or not to regulate 

radioactive pollutants based·on an 

a1111essment of risb to public health. 

After seeking public comment (44 fR 

21704 (April 11, 1979}), EPA listed 

airborne emissions of radionuclidea as 

hazardoua air pollutants under section 

112 or the CAA (44 FR 76738 (December 

Z7, 1979]). Based on that listing, EPA 

subsequently promulgated standards 

under section 112 for Department of 

Energy (DOE) facilities. Nuclear 

Regulatory Commission (NRC) licensed 

facilities and non-DOE Federal facilities, 

elemental phosphorus plants, and 

underground uranium minea (50 FR 5190 

(February e. 1985 and 50 FR 15388 (April 

17, 1985)}. 

On October 31, 1984, EPA issued·fts 

ANPR to Inform interested partie• that 

the Asency was considering iasuins 

standards under the CAA to limit radon 

emission• from licensed uranium mills 

(49 FR 43916 (October 31, 1964)). 

Subsequently, ~A entered Into a 

stipulation with the Sierra Club to 

promulgate such standards, or deliat 

radionuclides, by May 1, 1986. This 

agreement was entered as a consent 

order by the United Statea District Court 

for the Northern District of California 

(Civil No. C-34-0656 WHO). On February zt, 1986. EPA Issued 

proposed standards for radon emissions 

from licensed uranium mUla and · announced a public bearing (51 FR 638Z 

(February zt, 1986)). The bearing was 

held In Denver, Colorado, on March 25, 

1986 (51 FR 8Z05 (March 10, 1986)). A 

transcript of the hearing was placed in 

the Docket and the comment period was 

extended to April 28, 1986. Due to the complexity of the proposed 

rule and the need for an extended 

comment period, EPA and the Sierra 

Club e.ntered into a aecond atipulation to 

extend the deadline to August 15, 1986. 

The district court granted the extension 

on motion of the partie a. 

IV. Summary of Proposed Standards 

A. noted earlier. EPA published a 

proposed rulemaking regarding control 

of radon·ZZZ emissions from tailings 

piles at licensed sites on February Zt, 

1986 (51 FR 6382). That notice 

announced that EPA was considering 

various work practice standards for 

limiting such emissions based on ita 

preliminary conclusions that It ia not 

fea sible to set an emission• standard. 

and that the nature of the risk involved 

warrants a regulatory response. 

In its proposal, EPA presented three 

work practices, Including improved . methods for disposal of newly generated 

tailings, various timing requirements for 

use of these improved methods, and 

interim covers. The improved methods 

of disposal of newly generated tailings 

were a large, single pile with immediate 

cloaure. phased disposal. and 

continuous disposal involving 

dewatering and covering of tailings. EPA 

at.o atated It was conaidering 

alternatives of allowing new tailings to 

be added to existing pllea over a range 

of times, including 5 years, 10 years, 15 

years and an undefinite period of time . into the future. (An exception from the 

latter requirements was proposed where 

existing tailings Impoundments were 

lined.) · That proposal also discussed two . available optiona for controlling radonZZZ emlasions from existing piles. It 

concluded that earthen coven might be 

placed over dry taillnga beache• and· 

embankments constructed of sand 

tailings. It noted that dry beaches 

typically cover 60 percent of the total 

tailings area during the operational 

phase of a mlll and that this percentage 

could be significantly larger during 

periods of extended shutdown. It also 

noted that use of existing tailings piles 

could be terminated. While a dry out 

period would ensue during which 

emissions would unavoidably increase 

prior to disposal .in accordance with 

Federal standard• under UMTRCA. this 

Ia ao unavoidable result of disposal 

V. Summary of RNJMJDHS To Comment 

The Agency bas reviewed all · aubmittals to the docket and testimony .. 

given at the public hearing. A complete 

discussion of all substantive comments 

and the Agency's ~sponse to them 

appears in "Response to CommentsProposed Rule for Radon-ZZ2 Emissions 

from Licensed Uranium Mills Tailings" 

(EPA 500/1~1); the document may 

be obtained from the Program 

Management Office (ANR--159), Office 

of Radiation Programs. Environmental 

Protection Agency, Washington. DC 

20460. A aummary or major concerns, 

together with the Agency's responses. 

are presented below. 

Legal and Procedura~ 

Many commenters stated that there is 

no need for regulation under the CAA 

because existing regulations developed 

under the AEA and the UMTRCA and 

license conditions administered by the 

NRC and its agreement States .adequately protect the public from risk 

due to radon. The Agency estimates the 

individual lifetime risk may be as high 

as 1 in 100. assuming 70 years of 

exposure. The population risk is 

estimated to be 1 to 5 deatha per year 

under current Industry and regulatory 

conditions. The Agency believes that 

these riska are significant and that there 

Ia a need for standards under the CAA 

to protect public health with an ample 

margin of safety. 

A number of Ci>mmentera addressed 

ground water quallty·and stated that it 

·should not be considered In regulating 

radon under the CAA. The Agency has 

not developed this rule to regulate 

ground water. Ground water protection 

standard• ara currently in force and 

being implemented under the UMTRCA 

standards (40 CFR Part 192). However, 

potential effect• of various alternatives 

on ground water were considered as 

part of the analysis of the Impacts of this 

rule. since EPA has a responsibility to 

consider the lmpacta that Ita rules .may 

have on the total environment In part, 

this is done to ensure that regula tiona do 

not control pollution In one 

environmental medium only to degrade 
Federal Register I Vol. 51; No. 185 I W~dnesday, September 24, 1986 I · Rules and Regulations 34059 

-another. Consequently. there may be 

some additional ground water protection 

incidental to these standards. 

Some commenters stated that EPA 

should not considet cost and technical 

feasibility of regulation under section 

112 ofthe CAA. They maintain that the 

Congressional mandate directs EPA to 

adopt standards based exclusively on protection of public health. The EPA 

int.erprets the requirement of section 112 

to establish emission standards at a 

level which "provides an ample margin 

of safety" as not implying that these 

standards must ensure that there js no remaining levtil of risk. Consequently; 

the standard being adopted today 

requires the use of work practices that 

will reduce radionuclide emissions and · therefore risks to the practical minimum. 

The standard reflects consideration of 

the magnitude of the risks, the costs and 

availability of further controls and 

associated risk reduction potential, and 

the potential societal impacts of 

regulatory alternatives. The Agency, In 

considering the impacts. weighe9 the 

estimated risks achieved by and remaining after application of controls 

and their uncertainties against the costs 

to achieve the emission reduction and 

the potential for widespread closure. 

Some commentera stated that the 

Agency must promulgate an emission 

standard to be consistent with the mill - tailings disposal standards (40 CFR Part 

192), which are·partly in the form of a 

design standard: an emission rate limit 

per square meter of pile surface. These 

comments are based on a misconception 

of the disposal standards. The disposal· 

standards had multiple environmental 

goals including preventing misuse of 

tailings. reducing radon emission& for a long period of time. and protecting 

ground water. The Agency determined 

that the best way to accomplish these 

goals is through the use of a design 

standard based on a thicx barrier. The 

Agency found that a design standard 

limiting the rate of radon release was most appropriate given the many 

variables of location. tailings and earth 

characteristics. For example, a minimum 

thickness of barrier might not provide 

adequate protection under .all 

conditions. The prescribed standard, 

which requires the release of radon not 

to exceed an average of 20 picocuri ee . per square meter per second, is· a design 

standard requiring a certain 

effectivenese from a cover. The Agency 

stated that the standard was not to be · construed as an emission standard. 

"(T)he standard applies to design. · Monitoring.for radon after installation of. 

an appropriately designed cover is not 

required," making it analogous to· a 

work practice standard or design· standard authorized under section 

llZ(e). The Agency, thus, finds no 

inconsistency between the work 

practice standards for operations and 

the design standards for disposal. 

The NRC questioned wby EPA did not 

issue an emission standard. such as already exists in NRC and State 

regulations, instead of proposing a work 

practice standard. The Agency judges 

that it is not feasible to prescribe an emission standard since most of the 

radon emitted by a uranium mill comes 

from the surface of mill taUings.piles. A 

typical pile· may be from a few to 

hundreds of acres in area, and emissions 

from its surface cannot be controlled 

phases. "During· the first six-year phase, 

the operator may continue to place 

tailings' on existing piles. In the second· 

phase, this practice is terminated except 

for certain small piles and for those 

operators that make a satisfactory, 

individualized showing of low interim risk;l~.t the third phase. without 

exception, tailings may only be placed 

in impoundments meeting size and 

operating limitations designed to 

minimize exposed area and associated 

radon emissions. Taken as a whole. this 

scheme provides protection of public . health that meets the Act's requirements · 

of "an ample margin of safety". 

Technical. 

through a conveyance designed and Several commenters, in commenting 

constructed to emit or capture radon. It on the continuous disposal· method, · 

is also not practical to accurately and ·stated that the industry has minimal 

consistently measure emissions because experience with dewatering sands and 

or the large size of the tailings pile and ito experience with dewatering slimes. 

the continued modifications of the pile The Agency has found that although · that take place during operations. For continuous disposal has never been 

these and other reasons. a work practice actually practiced on uranium mill 

standard is being promulgated. It should tailings in the United States; it has been 

be noted that the NRC and State proposed by industry as the preferred 

regulations establish a concentration method of tailings disposal at three 

limit at the site. boundary in units of sites~ These proposals were never put 

quantity per cubic meter of air, but do into pr~ctice because of the down tum in not directly limit the quantity or rate of uranium production. The EPA believes 

radon emissions. · · that these proposals. submitted by 

'A commenter argued that EPA may industry, adequately demonstrate that 

not use a phased application of the work .. continuous disposal can be a viable practice requirements. since section 112 · option. It should be noted that the 

of the CAA permits only a two-year method has been included ·as an 

compliance waiver for the installation of allowable alternative for industry, but Is 

technology to meet an emission not'the sole practice required for new 

standard. However, the two-yl,!ar piles. It was included to provide 

compliance waiver discu.esed by the· industry with flexibility in the 

commenter Is not applicable to the management of new tailings. 

standard adopted. in this rulemaking. . Several commentera said that 

The Administrator has concluded that technology to dewater tailings exists, 

neither of the available interim work but Increased energy and manpower to 

practices, wetting or' interim cover. is an accomplish this are probably not 

appropriate measure to be imposed economically feasible. The Final 

generally under section tlZ. Also, is Background-Information Document and 

discussed in this notice. the the Economic Analysis reflect the 

requirements for new tailings additional costs and uncertainties In 

impoundments cannot be implemented dewatering tailings for the continuous 

'within two years. Consequently. the disposal option. The method has been 

two· year period that section . selected as a suitable work practice that 

112(c)(l)(b)(ii) provides "for the an operator may choose in lieu of 

installation of contrOls" bas no meaning phased disposal. 

or applicability here. As a result, ·the Several commenters stated that EPA's 

Agency has adopted a comprehensive assumption ·or 40 years of standby Is 

set of risk management requirements for excessive. One commenter stated that 

limiting radon emissions that fall under the assumption of a 40-year period 

the general category of "desigri, between the end of~ impoundment's 

equipment. work practice, or operational ueefulllfe and compliance with 

standard[s) ..... section 112(e). These · UMTRCA requirements· if~ reasonable. 

requiren:tents were designed as an The EPA judges that a 40-year standby 

Integrated program to require the period (which in practice could be · · maximum reduction of long-term cancer several different periods totaling 40· incidence attributable to uranium mill years) before ·r:eclamation to Federal 

taUings pilee that can be reasonably standards is a "worst-case" scenario. 

achieved. These standards operate in The Age!icy has estiRlated the f!ltallung 
34060 Federal Register I Vol. 51, No. 185 I Wednesday. September 24. 1986 I Rules and Regulations 

cancers committed under this scenario 

to serve as a point of reference and has 

also evaluated a ZO.year standby period 

scenario. Both periods were considered 

when the final rule was selected. 

Several commenters stated that it 

. would take about &'years to design, 

license and construct a new tailinBS 

management procesa. One commenter 

said it could take more than 10 years, 

and one commenter said 5 years was 

sufficient. The EPA agrees that, based 

on the comments received from the 

NRC. States. and individual companies, 

a 3-year period to design. license, and 

construct a new tailings impoundment Is 

unrealistically short. The Agency tudges 

that a period of 6 years is the time 

needed to desigq, permit. and conatruct 

a new tailings impoundment. Extensions 

to allow more time will be available, if 

due to circumstances beyond their 

control, mill operators are unable to 

complete a new impoundment within' 

that period. 

·Several commenters stated that more 

acc~rate site-specific emanation factors 

should be used as opposed to using the 

relationship of 1 pCi/m1 -t per pCi Ra226/g tailings. The Agency used a factor 

o£1 pCi/m1-s per pCi Ra-226/g of 

tailings for all dry areas and a factor of 

zero for wet areas. This nme factor was 

used for the UMTRCA rulemaking and is 

the factor used by NRC. An attempt was 

made to develop a formula. using site 

specl.fic characteristics. that would 

provide a more precise estimate of 

emissions. However. the formula bas not 

been verified by the Agency's internal 

review process or by Independent 

experts and data on the site-specific 

characteristics needed to derive such 

estimates are not available. For these 

reasons, the Agency decided to continue 

the use of the previously accepted 

factor. 

The NRC stated that recent literature 

indicates that a water cover may not be 

as effective In reducing radon emissions 

as previously thought. Recent technical 

assessments of radon emissions f.rom 

tailings covered with water are less than 

2 percent of emissions from dry tailings. 

The Agency believes that assuming no 

emi88iona from wet tailings a a compared 

to the more accurate 2 percent emission 

. rete is an Insignificant error in the 

context of this rulemaking. The Agency 

auumed an emission rate of zero for all 

tailings covered with water or saturated 

with water in estimating radon 

emiBBions. 

Risk 

A commenter stated that a sitespecific rule based on a lifetime risk of 

one In a million should be set for each 

mill to determine the allowable exposed 

surface area. The EPA has not accepted 

the proposition that the standard must 

reduce risk to a predefmed value, such 

as a level of one in a million. The EPA 

believes that it must protect' the public 

with an ample margin of safety and that 

this requirement provides the Agency 

with flexibility to consider the 

magnitude of the risks, the practicality 

of measures to reduce risks, and other 

relevant factors. This is a judgment 

based on many facton specific to the 

source category under consideration. 

Several commenters stated that radon 

e:qJosure from mill tailings on a regional 

and national level is overshadowed by 

background radon sources. Therefore, 

regional and national risk estimates are 

meaningless. The EPA agrees that radon 

e:qJosures due to mill tailings, at 

locations distant from mill tailings sites, 

are small compared to exposures from 

some other large sources. However, it 

does not follow that it is meaningless to 

calculate e:qJosure and risk due to 

emissions from such sites. These 

calculations are based on procedures 

generally regarded as sufficiently 

accurate to support the setting of 

regulatory standards. The significance 

of the risk is judged based on the value 

of the individual and population risk. 

and the regulatory options are a88essed 

based on the degree or risk reduction 

and the practicality and reasonableness 

of control measures. . Many commenten stated that the 

significance of effects of radon from mill 

tailings on total population is negligible 

because there are no proven adverse 

health effects. The Agency agrees that 

the adverse health effects due to radon 

emissions from mill tailings piles cannot 

be dil"lctly measured due to the high 

incidence of lung cancer from other 

causes. However. It would be Imprudent 

to use this as a reason not to regulate 

exposure to carcinogens. The risk 

estimates were derived from relative 

risk coefficients, the use of which was 

reco!Jlmended by the Agency's Science 

Advisory Board and represent current 

scientific knowledge. It is EPA's position 

that. based on current scientific 

evidence, excess lung cancers result 

from radon emitted by tailings piles and 

that the projected numbers of cancen 

calculated in the support documents are su.{ficient to support a ·rulemaking. 

Economic 

Several commenteH said that the 

proposed rules will have significant 

adverse effects on industry's ability to 

contain costs and will threaten the 

industry's future. EPA's analysis shows 

that the control me!l81.1res for new 

tailings disposal practices required in 

this rulemaking are similar in cost to 

alternative practices already required 

. by existing regulations and. therefore. 

the control measures required by this 

rule are not expected to affect the 

Industry'• viability. With respect to. 

existing tailings. the major coat of this 

rule to industry is moving the timetable 

for final cover for existing piles forward 

in time because the sooner new work 

practices are implemented, the sooner 

industry must undertake the expense of 

reclamation. Additional costs may arise 

in those cases where new capacity for 

tailings disposal will have to be created 

to replace the capacity lost during 

disposal of the existing piles. As 

Indicated In the Economic Analysis for 

this rulemaking, EPA projects that this 

Impact will not threaten the viability of 

this industry. The Agency concluded 

that the costs are reasonable in relation 

to the benefits derived and that this 

action is consistent with previous 

Agency actions. 

VI. Summary and Rationale of F'mal 

Rule 

A. Summary 

Baaed on currently available 

information, EPA bas determined that it 

is not feasible to prescribe an emission 

standard for radon emissions from 

urenium mills. Radon is emitted from the 

surfaces of tailings piles in a manner 

analogous to fugitive dust emissions and 

cannot be emitted through a conveyance 

deeigned and constructed to capture 

such radori emissions. Instead. EPA is 

requiring an improved work practice for 

the disposal of newly generated tailings 

and Is specifying a date by which all 

newly generated tailings must be 

managed by this work practice. 

EPA expects that, when tailings can 

no lo~er be placed on an existing pile. 

Federal and State regulatory agencies 

will promptly move to require disposal 

of the piles to Federal standards 

established by the EPA and 

Implemented by the NRC under the AEA 

as amended by UMTRCA. 

This work practice requires that new 

tailings be disposed of either in 

impoundments that are no larger than·.w 

acres or by the use of continuous 

disposal in which no more than 10 acres 

of tailings are exposed at .any one time. 

All new tailings impoundments must be 

designed and constructed to meet this 

. work practice. Using the first alternative 

would require a series of impoundments, 

each constructed with earthen dikes or 

In a excavated pit and each having a 

liner as required by .W CFR 192. As each 

Impoundment it filled, It would be dried 

out and covered with earthen materials 

immediately. This design permits the use 
Federal Register I Vol. 51, No. 185 I Wednesday; September .24. 1986 I Rules and Regulations 34061 

of a water cover over aU ·tailings during 

operations without risk of contaminating. 

ground water. The water cover seals in 

the radon. greatly reducing radon 

emi .. ions to air. Also, a series of 

impoundments significantly reduces the 

amount of unreclalmed tailings at the 

end of a miU'slifeUme because only one or two impoundments would still require 

closure. By making final reclamation 

easy, the potential for larser areas of dry 

tailings to remain uncovered Ia avoided. 

and this too. greatly reduces radon 

emissiona. 

The second procedure, continuous 

disposal, is similarly effective. If tailings are dewatered and immediately buried on a continuous basis. radon emissions 

during the operational phase of the mill are greatly reduced. At the end of the 

mill's lifetime, only about 10 acres of 

tailings require· final reclamation. There 

is, thus, no potential for large areas of 

tailings to remain dry. and uncovered as 

a source of radon emissions. A liner is 

used to protect ground water. 

At mill sites where there are existing 

tailings piles. this work practice is to be 

phased in on a reasonable schedule. No 

later than 2 years after the effective date 

of this rule, all owners will either certify 

to the Administrator that they do not 

Intend to build a new tailings 

Impoundment, or if they wish to build new tailings impoundments they must 

apply to the Administrator for approval 

to construct. Within 60 days following 

the Administrator's approval, the owner must apply to the NRC for a license to 

construct. Following the granting of a 

license by NRC. construction must begin 

promptly and must be completed in not 

less than 30 months. The entire process 

must be completed by December 31, 

1992. If the owner is in c:Ompliance with 

this schedule, new tailings can continue 

to be placed on existing piles until the 

new impoundments are ready. Those owners not building new impoundments 

may also continue to use their existing 

piles until December 31, 1992. An exception from the preceding 

schedule allowing for continued uae of an existing tailings pile will be granted 

upon petition to the Administrator. provided the existing pile meets one of 

the following conditions: (1) The existing 

pile is 40 acres or less and Is lined or, (2) 

the ·combined area of all piles· at the site 

Is less than 20 acres. Each exception will 

last for five years, at which time the owner may request a new exception. A discretionary extension for all or some of the milestones on the preceding 

schedule. allowing for continued uae of an existing tailings pile, may be-granted 

upon application to the Administrator 

for one of the following reasons: (1) The owner demonstrates it cannot, due to 

circumstances beyond its control, complete a new Impoundment before a 

construction achedule milestone date or 

(2) the owner or operator demonstrates . 

that an extension Is consistent with the 

CAA. To make such a demonstration, 

the owner must certify that the millis in 

compliance with applicable EPA · 

standards and NRC regulations and 

license conditione. and makes a . submittal showing that the public Ia 

protected with an ample margin of 

safety taking into account the size and 

condition of the pile. riska to nearby 

individuals.and p·opulation.lengtb of 

extension requested, risk reduction 

practices in effect, and the expected 

level of future mill activity. An extension may be granted for a period 

not to exceed 5 years, although the miU owner will be able to apply for more than one extension. 

No exception or extension is effective 

after December 31, zoot and no new 

tailings may be placed on any existing 

tailings pile after that date. 

B. Options CoMidered 

In developing thia rule, EPA reviewed a variety of options in the light of 

comments received on Its proposal. A . fundamental step in this process waa tecognizing that the opportunities for 

regulatory response to the risks Involved were different for existing·tailings and 

for new tailings. EPA's analysis of 

regulatory options proceeded on the 

basil of this recognition. 

With respect to tailings that would be 

generated in the future, EP/i recognize• 

that improved work practices were available that could Umit the period 

during which tailings were exposed . prior to disposal. IJmiting thia exposure 

would correspondingly limit risk to 

health. The work practices that EPA 

examined reduced this exposure In ~o 

ways: _first, by placing the tailings on 

sites smaller than Is now the practice; 

second, by placing cover on the tailings 

continuously or at intervals. EPA 

analyzed options for new tailings that 

varied both 88 a function of size and as 

a function of time. With respect to tailings that already 

existed, EPA's ability to identify .work 

practice improvements that would limit 

emissions was more limited. The most 

direct means for reducing exposures, i.e., a permanent thick earth cover or water 

cover, could conflict with continued uae of the pile or exacerbate ground water 

problems. Measures involving interim or partial use of earth or water covers were also evaluated. These options are 

described elsewhere in this notice. 

Indirect means of reducing exposures 

were also explored. These baeically 

involve limiting the use of the existing 

pile for depoeit.lon of new tailings by 

limiting the period during which new 

tailings could be placed on the piles. On 

analysis. EPA concluded that-volume 

restrictions would prove difficult to 

administer and that a more feasible 

approach would be to limit the future 

use of existing piles. In the end, EPA 

decided that risk reductions should be 

reconciled with continuity of mill 

operations by phasing in the transition 

to new disposal methods. The best 

currently available information . 

indicates that it will require about six 

years for a source to phase in new 

capacity. The specific options -considered are discussed below. 

Interim Cover for Existing Piles 

The Agency's proposed rule contained an alternative work practice for existing 

tailings piles consisting of interim earth 

covers placed on the sides and topJ of 

dry tailings piles. An Interim cover on 

dry tailinga acts to reduce emlasions of 

radon. In a wet pile. water acta to 

prevent radon eqllsslons so that interim covers are not needed for the wet 

surfages. Upon reexamination of the 

interim cover alternatives and after 

consideration of the comments received 

on that issue, the Agency bas . determined that such covers are not an appropriate work practice to be required 

under this. generally applicable rule. 

EPA's model of the interim cover 

alternative used in the analysis of the 

proposed rule was overly simplistic. · 

Sources of error included the following 

factors: 

1. The model did not consider tailings 

piles that go on and orr standby 

repeatedly. In these situations, the ·interim cover is buried under new 

tailings followed by application of a 

new interim cover. 

Z. The model aesumed the dry areas of 

the pile are covered immediately and 

that the pile remained on standby for an extended period of tlm.e. This Ia unlikely, 

because regulatory agencies would require the operator to reclaim sooner 

than 40 years. 

3. Maintenance costs for interim 

covers were ignored. 

4. Covering high. steep slopes with 1 

meter of earth is a difficult engineering 

feat and may be mora expensive and 

impractical than the model assumed it to . be, and in practice may endanger 

workers. 

s. Slimes may underlie taUings 

considered to be dry, making such 

tailings uncoverable because heavy 

equipment necessary to apply the cover 

would sink into the pile. If dry tailings 

cannot be covered, this would reduce 

benefits. 
34062 Federal Register I Vol. 51, No. 185 I Wednesday, September 24, 1986 I Rules and Regulations 

The Final Background Information 

Document and Economic Asseasment 

containe a rnited model that attempts 

to account for these factors. The Agency 

now believes that interim cover is 

inappropriate as a generally applicable work practice. The appropriateness of interim cover 

can only be evaluated on a site-by-site basis. Though ita uae In some cases 

would be practicable and could lead to 

significant risk reduction, in othen it 

would have dubioue riak reduction . benefits, coets that appear unwarranted 

as one of two alternative work practices required by the final rule because it 

reducea health riaka due to radon from 

taUings, providing public health 

protection with an ample margin of 

safety during the operatmslifetlme of a 

uranium mill tailings impoundment. In 

this disposal scheme, a aeries of small 

Impoundments Ia con1tructed over the 

lifetime of a mill. Each small 

impoundment would be consttucted 

with earthen dikes or in an excavated 

pit and, under existing Federal 

regulations. muat be lined to prevent ground water contamination. After each 

impoundment. fills, it will be dried out 

and covered with earth as soon as 

practical. Disposal costs will be ·spread 

over the operating life of the mill. The 

in relation to thoee benefits, and would 

present hazarda to the eafety of workera. 

Moreover, enforcement of a requirement for Interim covers would be difficult and 

controversial because it would not be 

obvious which parts of the pile are dry 

enough to eover and whether future 

operational plana are firm enough &0 

that it ie reasonable to delay application of an Interim cover. 

· design permits the use of a water cover 

over moat of the taUings, with only a 

small risk of contaminating ground 

water. 

The Agency believes that in 

establishing generally applicable standards it should seek permanent solutions rather than temporary ones. 

Interim earth covers are temporary because they are often covered by new 

tailings when the m!U retuma to · operation. The new tailings on top of the · interim cover release radon. removing the beneficial effect of the cover. The 

value of the Interim earth cover is also 

lost when the final cover required by Federal Regulations le put In place. Final 

reclamation normally requires piles with 

steep sand dams to be recontoured to a 

more etable shape. Any interim cover 

would be lost due to mixln8 with the 

tailings during the recontouring. A better 

use for the limited reaources available to 

the producers of uranium would be final 

disposal consistent with federal 

standards. 

The State of New Mexico expressed 

concern about severe additional 

environmental impactt due to the 

diaruption of many additional acres of 

land to obtain cover material. The NRC 

raised serious safety concerns for 

interim coven. The NRC stated that 

interim coven on dams would interfere 

with Important safety practices. such as 

movement monitors for tailin8s dams. 

They also stated that covering of certain 

drain portions of the dams could 

seriously reduce their stability. ·. In 1ummary, the Agency concluded 

that requiring operators of existing tailings piles to immediately add and 

maintain interim earth covers on all dry 

surfaces ia not an appropriate generally applicable work practice. 

Phased Disposal 

The Agency is eelecting phased · disposal for new tailings impoundments 

An important benefit of phased disposal is that it eliminates the 

difficulties and expense of reclaiming large tailings piles at the end of the 

impoundment life. By limiting the size of 

the piles, very large areas of tailings are 

prevented from becoming expoeed to 

air, drying out. and emitting radon 

during extended standby periods. At the 

end of the mill's lifetime, only one or 

two impoundments will still require reclamation. 

These characteristics of phased disposal combine to reduce radon 

emissions. The liner under the tailings pile helps maintain wetness of the 

tailings by preventins water from 

leaching into the sround. This not only 

protects sround water. but also greatly reduces radon emissions by keepins the 

tailings wet Experience with phased disposal shows that the tailings often 

stay so wet that water must be pumped 

out of the impoundments. Since control of radon emissions is 

achieved by keeping the tailings 

saturated or covered with water, it Ia 

important that impoundment liners have 

water retention capability. In most cases 

eligible for thia exception, impermeable synthetic liners will be required. 

However, UMTRCA standards (40 CFR. Part 192) allow an exception from the 

synthetic liner requirement if it is 

demonstrated that ground water 

contamination will not occur. 

The size of the pile also helps reduce 

emisaions. It doee so by reducing the 

time for the dry out and standby period& that precede final cloeure, when radon 

emissions are at their highest. Since the 

piles are smaller, they dry sooner, and 

the expoeed surface area ia reduced. Closure Ia relatively easy and 

inexpensive, reducins the incentive for 

the owner to delay disposal. To further 

reduce the time before closure, this rule 

allows a company to operate a 

maximum of two tailings Impoundments 

at once. Companies can legitimately need two operating piles to work most 

efficiently-(especially when one pile is 

almost full), but by limiting an owner to 

only two operating plies. an owner must 

close ita first pile before it opens ita 

third pile (or close ita second before it 

opens the fourth. etc.). This incentive 

will work to reduce etandby periods. Phased disposal, therefore. is a 

tailings management system in which · tailings are kept wet until they are dried 

and disposed. Radon emissions are 

reduced while the pile Ia in uae and 

while the pile is on standby. This results 

In a large reduction of the total 

emissions from mill tailings pile and, 

therefore, protects public health with an 

ample margin of safety. 

Constructing, filling. and reclaiming tailings impoundments in series coets 

Jess than using a single. large impoundment when a reasonable (5!11i) 

discount rate is used. This lower cost 

reflects the lower Initial capital expenditures for phased disposal. Further coat savings may be realized in 

phased disposal by using excavated 

earth from future impoundments to 

reclaim filled, dry impoundments. Phased disposal is the best available 

demonstrated technology for uranium 

mill tailings management. The two mills 

most recently licensed by the Nuclear 

Regulatory Commisaion use phased disposal designs. The Agency also considered a 20-acre 

limit for each phaaed disposal 

impoundment in the proposal (51 FR 

6382). One commenter found a 20-acre 

limit acceptable but stressed the need 

for economic assessment of size limit a. 

Several commentera argued that the 

Agency should allow flexibility for sitespecific considerations and should not 

dictate a specific limitation. The Agency evaluated both 20- and 40-acre phased disposal options. It found that the 40-

acre impoundment provides about the 

same health protection as the 20-acre 

impoundment, but at a slightly lower 

cost. The Agency concludes that a 40-

acre 'size limit for phased disposal 

protects health with an ample margin of 

safety, as required by section 11Z. The 

40-acre impoundment is the maximum 

size allowed under the rule; an operator 

can choose to build a smaller one. 

The 40-acre phased disposal work 

practice. provldas considerable 

flexibility for constructio~ and operation of tailings impoundments, although all 

existing rules (includins 10 CFR Part 40 

and 40 CFR Part 192) muet still be 

followed. For example, under this work 
Federal Register I Vol. 51, No. 185 I Wednesday, September 24, 1986 I Rules and Regulations 34063 

practice. impoundments can be 

constructed in hollow• by building a 

dam acroea the hollow and storing the 

tailings on the upstream side. The 

standard only limita the total area of 

any impoundment used for storage of 

uranium mill tailings; other lite-specific 

design considerations are not affected. 

Liners are required at all new uranium 

tailings impoundments under existing 

rules (40 CFR Part 192). The tradeoff& 

between potential problema and the 

advantages of liners were considered in 

that previoua .rulemaking (48 FR 45926). 

Continuoua Disposal 

The Agency selected continuous 

disposal as an alternative work practice 

under the final rule because It reduces 

health risks from radon from tailings to 

the same extent as phased disposal and 

provides quick reclamation of the sUe. 

This disposal method calls for tailings to 

be dewatered as they are generated. 

placed in pits or on pads, and covered 

with about 3 meters of earthen materials 

on a continuoua baais. Disposal pita or 

pads would be constructed with 

impermeable liners. This method would 

rely on a thick earth cover to reduce 

radon emissions rather than on water as 

in the phased method disposal During 

operation. no more than tO acrea of 

tailings could be uncovered at any given 

time. To aBBure that the water remaining 

in the tailings after dewatering (wblch Ia 

never completely effective) and rain 

water does not seep throiJ8h the tailings 

and contaminate ground water. a 

continuoua disposal impoundment is 

lined in accordance with 40 CFR 192.3Z. 

The potential for ground water 

contamination is nesllglble. 

A second Important benefit of 

continuous disposal is that It would 

eliminate the difficulties of reclaiming 

large tailings piles at the end of the 

impoundment life. By requiring disposal 

of tailings u they are generated, very 

large areas of tailings are prevented 

from beins exposed to air, drying out. 

and emitting radon during extended 

standby periods. 

The technology of continuous disposal 

has not been demonstrated for uranium 

mill tailingS in the United States. 

However. the induatry hae proposed this 

method for use at three aitee. The 

decline in uranium demand is one of the 

major reasons why none of these 

proposals wae put into practice. Tail.i.ngs 

dewaterlns systems have been used 

successfully at nonfenous ore 

beneficiation mille. The Agency believe• 

that these proposals and experience• 

demonetrate that continuous diapo&al 

can be a viable work practice. 

Flexibility ia provided to allow 

designs that can take advantage of site-

. specific characteristics. For example. 

there is no requirement that tailings be 

disposed of below surface level and no 

restrictions that limit the use of 

topographical features of a site as 

tailings dams. However, aU existing 

regulations still apply; 

Although the industry commented that 

continuoua disposal ie not practical. thie 

is not a persua~ve argument, since at 

least three companiea have chosen this 

method as their-preferred disposal 

method in detailed site design plana and 

applications. Also, as noted above, 

dewatering tailiilgs has been performed 

in other extraction industries. The 

Agency decided to allow the industry to 

select either continuoua or phased . 

disposal because both methods provide 

similar levels of radon reduction and 

either method could be preferable to the 

other. depending on the specific 

physical, environmental. or economic 

conditions that exist at the site. 

C. Existing Piles 

The regulation of uranium mill tailings 

disposal piles requirea different 

approaches to new and existing taUinp 

impoundments. From the standpoint of · 

risk reduction. new impoundments can 

readily be designed and operated in · 

order to achieve substantial reduction of 

risk at a reasonable cosl EPA. thua. haa 

adopted atandarda that have the effect 

of limiting the total exposed surface 

area during the active phase of an 

impoundment's existence. Existing 

impoundments present more difficult 

regulatory problems. They were 

constructed over a thirtY. year period. 

range in size from a few acres to several 

hundred acres. and are located in 

different areas with di!ferent 

topography, soil charac.terlstics, tailings 

characteristics, and other factors 

affecting health risks. Consequently, 

they are not auaceptible to a single 

regulatory scheme of the sort adopted 

here for new impoundments. In addition. 

.the NRC and their agreement States 

resulate practices at these sites on a 

site-by-site basis. For example, the NRC 

baa stated In comments that it typically 

requires interim cover for the purpose of 

dust control on appropriate portions of 

existing piles. 

EPA investigated work practices that 

might be imposed generally upon 

existing tailings piles that would reduce 

risks until they are closed and raplaced 

with new piles. Aa discuBBed previously. 

the Agency found that the two principal 

options, wetting and interim cover, 

· made no sense to impose as acrose-the· 

board requirements. While Interim cover 

has theoreticalappUcabillty. Its risk 

reduction is not great in many 

situations, and coats are 

disproportionate to that limited 

reduction of risk. Wetting. particularly 

in unlined impoundments in arid areaa 

or the Southweit, yields some risk 

reduction but again at a 

disproportionate cost. Moreover, wetting 

at unlined impoundments can lead to 

ground water contamination. 

exacerbating a problem that several 

. operators are now trying to ·remedy. 

EPA believe• that the reasonable 

course to deal with these impoundments • 

is to adopt requirements that will 

encourage their closure, in the long tenn. 

in accordance with requirements set by 

EPA and the NRC. At the same time, 

these requirements must be tempered 

with flexibility for the particular 

circumstances of individual 

impoundments. It ia reasonable to do 

this in light of the wide disparity in risk 

from different existing impoundments. 

and the small number of those 

impoundments. · 

Accordingly, the ~I rule senerally 

requires the cessation of disposal of 

tailings at existing impoundments six 

yean after promulgation of these 

resulations. The requirement for 

cessation of disposal will remove any 

obstacle for the NRC or an agreement 

state to require. after an appropriate dry 

out period, fmal closure of the 

Impoundment. since it can no longer be 

used for disposal of newly generated ' 

tailings. In EPA's view, the risk that will result from thia phase in period of 

continued disposal at exiating 

impoundments is consistent with the 

protection of public health with an 

.ample mal'8in of safety. 

Exception for Existing Lined 

Impoundments 

The Agency bas determined that 

certain existing tailings management 

·impoundments presently meet the 

requirements of the new work practice 

standards. Therefore, the Agency is 

providing an exception from the 

schedule requirements. which are 

specified below, for impoundment 

designs that are no larger than 40 acres 

and have a liner meeting the 

specifications of 40 CFR 192.32. This 

requirement assures that the 

impoundment has the capability to 

retain water, thereby keeping tailings 

wet and greatly reducing radon 

emissions. 

Exception for Small Tailinp Piles 

The Agency,ln its examination of the 

uranium milling induatry, has discovered 

that each mUlls unique and that not all 

mills present a significant health risk to 

the public. The Agency found that one of 

the most impo"ant mill characteristics 
· 34064 Federal Resister I Vol. 51, No. 185 I Wednesday, September 24, 1986 I Rules and Regulations 

that affect risk Ia the size of the mill 

tailings pile. The Agency also found that 

milia having combined pile areas 

smaller than 20 acres have very small · radon emissions. The A8ency belie.vea 

that such a mill doea not threaten pubUc . health. Therefore, the Agency has 

decided to except them from the 6-year schedule. Such an exception is 

consistent with protection of public health with an ample margin of safety. 

D. Schedule for Standards 

Implementation 

The Agency Ia requiring that all 

tailings generated at existing millaitea 

after December 31, 1992, be managed by 

one of the work practices specified in 

the final rule. By phasing out existing tailings piles and requiring new tailings generated at existing mill sites to be 

placed in impoundments subfect to the 

new work practice, risks to individuals 

and populations are. reduced and the 

public ia protected with an ample margin of safety. The Agency Ia 

assuming that. when tailings can no 

longer be placed on existing piles, 

Federal and State regulatory agencies will promptly move to require reclamation of the piles to Federal 

standards establiabed under the ·AEA 

through UMTRCA. 

The Agency i8 aware that section 112 

baa provided for only a 2-year compliance waiver. However, it l:a· 

Impossible to design. license, and build 

a new tailings impoundment in that 

short period of time. The opera ton of 

existing mills are given the time 

necessary to install new impoundments. To aSBure that new tailings impoundments are built and used as 

soon as practical, the Agency has 

established a strict schedule witb 

milestones for meeting regulatory requirements and construction of the 

facility. Industry Ia provided with 

sufficient time to prepare new 

impoundments while, simultaneously, 

there is a strict timetable that must be 

met. This timetable is designed to be 

flexible to assure that if time is saved in 

one part of the procesa tlie 

impoundment will be ready sooner. The 

rule also provides an extension 

mechanism to give operators a chance to 

have more time if, due to circumstances 

beyond their control, they are unable to 

meet the schedule. The Agency haa examined the effect 

from the continued use of existing piles during the 8 years required for the 

construction of new tailings impoundments. In performing the 

analyaia of the effect of allowing all 

mills to operate for 8 years, relevant 

radon emissions come only from some 

of the mills. Since EPA's original 

analysis, 3 of the ZO mills have alated an 

Intent to go to closure and. therefore, are 

not effected by this standard. The 

resulting risk from radon emissions in 

allowing all other mill• to operate for 6 

years is not significant. The uae or these 

mills for this short time period 

represents a marginal risk that does not 

justify the economic waste of requiring a 

mill owner to build an Impoundment that the owner has no intention of using. Because bf these low risks, operators of 

exiating pilee who want to continue to 

uae their existing piles may do so for the ~year period. Any owner or operator of a licensed 

uranium mill who wishes to continue to 

use existing tailings impoundments must 

submit an application to the 

Administrator for approval to construct 

8 new impoundment or certify that they do not intend to build 8 new 

impoundment. Thia should be done as 

soon.as possible, b'ut no later than Z 

years after the effective date of this rule. 

This period'ls necesaary to provide the 

time needed for owners to decide 

whether or not to build a new 

Impoundment and. If they decide to 

build a new Impoundment, it also 

provides the time needed for the 

purchase of a site, for the collection of 

site data and for the design and . preparation of licensing material for 

EPA and NRC. Owners not building new 

Impoundments may continue to use their 

existing pilee until December 31, 1992. 

The Agency anticipates an Internal 

review and decision period following submittal of a complete application. After the Agency's approval to 

conatruct. the owner or operator must 

apply to the NRC within 60 days for a 

license to conatruct a new tailing& . impoundment under 10 CFR 40. The 

Agency anticipates that NRC will act 

promptly on the application. Following the receipt of a license from the NRC. 

the owner or operator must then start 

construction of an impoundment within 

90 days, weather permitting, and must 

complete construction within 30 months. 

The Agency proposed alternative 

schedules of immediate, 10 years, 15 

years, and no time limit for mandatory 

use of work practice standards. 

Comments from the NRC and the 

industry agreed that new impoundments probably could be built in 6 years. 

Although one industry commenter 

estimated that it would take more than 

10 years to finish new impoundments, in 

general. the record did not support a toyear option. 

E. Schedule Extension 

The Agency recognizes that strict 

adherence to the achedule may not 

always be possible or reasonable. The 

Agency may grant an extenaion for any · schedule milestone for certain reasons. 

The first reason for the extension Is 

practicality. The Agency is allowing mill 

owners 6 years to build new 

lmpoun«;imenta, because it ia the 

Agency's estimate, aupported by the 

record, that 6 years Ia normally a 

sufficient time to design, license and 

build a new uranium mill tailings Impoundment. But the Agency 

recognizes that, due to circumstances 

beyond the mill owner's control, 

situations can arise that delay . completion. In these situations, the mill 

owner can apply for a schedule 

extension to provide him with sufficient 

time to complete the new impoundment. 

There ere other reasons why an 

extension may be required. For example, 

as previously noted. each mill is unique and individual milia may present amall 

risks to public health. To take care of 

any of these situations. the Agency may 

grant an extension, provided tbat the 

mill owner can demonstrate that the 

extension, under conditions existing at 

the thne of the request, Is consistent 

with protection of public health with an 

ample mafgin of safety as specified in 

t 61.2SZ(e}. This extension may be 

granted for any schedule milestone. For 

example. the Agency expects that 

extensions would be granted £or mills 

with moderately sized piles and that 

have no people living nearby. Such mills · present small riska to maximally exposed individuals and small risks to 

regional and national populations. The 

Agency may grant an extension, 

conditionally if required. only upon 

finding that thla extension p~tects 

public health with an ample margin of · safety. 

The Agency may grant these 

extensions based on an examination of 

factors relating to the overall remaining health risk. including the size, condition, 

and location of the pile. the length of 

extension re~ueated, the expected level 

of future activity, and any risk reduction 

practices the mill owner has undertaken 

or pledges to undertake. 

VII. Implementation of the Final Rule 

Operatorll of new tailings impoundment• constructed after the 

promulgation date of thla rule must 

apply to the Administrator of EPA for 

approval to construct a new 

Impoundment pursuant to aection 61.07 

of the Clean Air Act. 

Operators of existing tailings impoundment should follow the 

implementation 'plan detailed in I 81.252 

(b) or (c). If the Administrator finds, on 

the baals of any available information 

that there is a violation of any 
Federal Register I Vol. 51, No. 185 I Wednesday, .September 24, 1986 I Rules and Regulations 34065 

requirement of an applicable 

implementation plan, the Administrator 

will enforce with remedies described in 

section 113 of the Acl 

Operators of existing tailings pileS 

who wish an exception listed In 

§ 61.252(d) from the schedules listed in 

§ 61.252 (b) or (c) in order to continue to use a pile should write to the · 

Administrator, providing the reason why 

the exception Is warranted. The . 

Administrator will grant. grant with 

conditions. or deny the exception. If 

granted. the owner must reapply to EPA 

every 5 years that It still meets the 

criteria for exception. If at anytime 

neither of the exceptions criteria apply, 

the owner must notify the Agency and 

immediately ceas&""use of the pile. 

Operators of existing tailings piles 

who wish extensions from the schedule 

milestones listed in§ 61.252 {b) or {c) in 

order to continue to use an existing 

tailings pile should write to the 

Administrator providing the reasons why an extension should be granted, 

taking care to provide the infonnation 

requested in § 61.252(e). This must be · done at least 1 year before the milestone 

date for which the extension is 

requested. The Administrator will grant, 

grant with conditions, or deny the 

extension within 9 months. Although 

multiple extensions may be granted. 

each extension will last no more than 5 

years. 

All requests should be sent to the 

Assistant Administrator for Air and 

Radiation (ANR-443), U.S. 

Environmental Protection Agency, 401 M 

Street, Washington, DC 20460. 

No exception or extension will be 

effective after December 31, 2001. This 

deadline allows owners of existing 

tailings impoundments a chance to use 

those impoundments in those cases where to do so would not endanger 

public health. while assuring that the 

system of exceptions and extensions 

will not be subject to any potential 

abuse by mill owners. In this way, the 

rule will cause even greater reduction in 

radon emissions as phased or 

continu~us disposal methods are implemented. 

Nothing In this rule is Intended to 

affect the existing regulatory authority 

of the NRC. EPA hopes that it will be 

able to reach an agreement with NRC to 

allow NRC to take an important role in 

the implementation and enforcement of 

this rule. This would allow EPA to take 

full advantage of NRC's expertise in this 

field and help minimize the duplication 

of effort and conserve administrative 

resources in accord with § 12.2 of the 

Clean Air Act. 

vm. Miscellaneous 

.A. Docket 

The docket is an organi:ed and 

complete file of all infonnation 

considered by EPA fn·the development 

of this proposed standard. The docket 

allows interested persona to identify 

and locate documents so they can 

participate effectively in the rulemaking 

process. It also serves as the record for 

judicial review. 

Transcripts of the hearings, all written 

statements, the Agency's response to 

comments, and other relevant 

documents are placed in the docket and · are available for l.napection and copying 

during nonnal working hours. 

B. Executive Order 1.2291 

Under Executive Order 12Z91, issued 

February 11, 1981, EPA must judge , 

whether a rule is a "major rule" and, 

therefore, subject to the requirement of a Regulatory Impact Analysis. The EPA 

has determined that this rule is not a 

major rule as defined In section l (b) of 

the Executive Order because the annual 

effect of the rule on the ·economy will be 

less than $100 million per year. Also, it 

will not cause a major increase in costs or prices for any geographic region. 

Further, it will not result in any 

significant adverse effects on competition. employment, investment, 

productivity, innovation. or the ability of 

the United States enterprises to compete 

with foreign enterprises in domestic or foreign markets. Under Executive Order 12291, this rule was submitted to the 

Office of Management and Budget 

(OMS) for review. Any comments from 

OMB to EPA and any response to .those 

comments are included In the docket. 

C. Paperwork Reduction Act 

The fmal rule does not impose any 

reporting or recordkeeplng requirements on operators of uranium mills and 

associated tailings piles. 

D. Regulatory Flexibility Analysis 

Section·eoa of the Regulatory 

Flexibility Act, 5 U.S.C. 603, requires 

EPA to prepare and make available for 

comment an "initial regulatory . flexibility analysis" in connection with . any rulemaking for which there is a statutory requirement that a general 

notice or proposed rulemaking be 

published. 

However, section 604(b) of the . Regulatory Flexibility Act provides that 

section 603 "shall not apply to any . proposed . . . rule if the ·head of the 

Agency certifies that the rule will not. if 

promulgated have a significant 

economic impact on a substantial 

number of small entities." 

The EPA believes this final rule will 

have little or no'impact on small 

business ·because the total costs 

associated with the standards will have 

relatively little impact on the total cost 

of producing uranium oxide. 

For the preceding reasons. I certify 

that this rule will not have a significant 

economic impact on a substantial 

number of small entities. 

E. General Provisions 

The general provisions of 40 CFR Part 

61, Subpart A apply to all sources 

regulated by this rule, except as otherwise noted. 

F. State Implementation and 

Enforcement of Emission Standards 

. Under section 112(d)(1) of the CAA. 

any State may develop and submit to 

the Administrator a procedure for 

implementing and enforcing emission 

standards for hazardous air pollutants 

for stationary sources located in such 

State. If the Administrator finds a · State's procedure for implementing the 

standard is adequate, the Federal 

authority then is delegated to the State. 

To streamline this procedure, some of 

EPA's Regional officas have entered into 

agreements with certain States for 

"automatic" delegation of new section 

112 standards. Under this arrangement, 

States are delegated authority to 

implement.and enforce all new section 

112 standards when they are Issued. 

The Agency has decided that 

"automatic" delegation shall not be 

made for the radionuclide NESHAPa. 

When EPA entered into these 

agreements, the State's capabilities and 

expertise with respect to radionuclides were not considered. Therefore, States 

must reapply for delegation in the case of radionuclide NESHAPs. 

G. Relationship to Other Programs 

It Ia important to note that EPA has 

authority to regulate QJining wastes. under the Resource Conservation and 

Recovery Act (RCRA). aa well as the 

CAA and UMI'RCA: Since the consld~rations under each statute may 

vary, the regulatory program for 

uranium mill tailings under the CAA and 

UMTRCA might well differ from the 

program EPA intends to develop for 

mining waste under RCRA. The RCRA 

program will be tailored to the risks 

associated with mining wastes and the 

technical feasibility of various control . options (see 51 FR 24496: July 3, 1986). 

H. Communications 

Communications with the 

Administrator regarding the reporting 

and recordkeeplng requirements of this 

·' 
34066 Federal Register I Vol. 51, No. 185 I Wednesday, September· 24, 1986 I Rules and Regulations 

rule, as well as requests for-waivers, 

shall follow the provisions of Part 61.10, 

except as otherwise noted in this rule. 

This rule is effective immediately for 

new sources and existing facilities. 

Those facilities that are not in 

compliance with the final rule based on 

infonnation currently available to them, 

may request a compliance waiver from 

the Administrator under the provisions 

of section 112(c)(t). 

List of SubjectS in 40 CFR Put 81 

Air pollution control, Hazardous 

materials, Asbestos, Beryllium, Mercury, 

Vinyl chloride, Benzene, ArseniC: and 

Radionuclides. 

Dated: AIJ8Ual 15, 1986. 

Lee M. Tbomu, 

Administrator. 

PART 61-(AMENDEDJ 

Part 61 of Chapter 1 of. Title 40 of the 

Code of Federal Regulations Ia amended 

as follows: 

t. The authority citation for Part 61 

continues to read as follows: 

Authority: Secll. 112 and 301(a) Clean Air 

:Act, aa amended [42 U.S.C.7412 (a}); 

2. By adding a new Subpart W to read 

as follows: · 

SUbpart W-Naltonll Ern18a1on Standanl for 

Radon-222 Emlselona From Ucensed . Unmlum Mil Tdlnp 

Sec. 

61.Z50 Applicability. 

61.251 Definitions. 

61.2.5Z Standard. 

SUbpart W-Natlonat Emlaalort 

Standard for Radon-222 Emf88lon8 

From Ucensecl Uranium MUI Tailings 

t t1.260 ~. 

This subpart applies to licensed sites 

that manage uranium byproduct 

materials during and following the 

processing of uranium ores, commonly 

referred to as uranium mllla and their 

asaoclated tailings. Thla subpart applies 

during the period of operation. · · 

161.261 Deftnltlons. 

As used in this subpart, all terms not 

defined here shall have the mea.nins 

given them in the Clean ~r Act or 

Subpart A of Part 61. The following 

tenus shall have the following specific meanings: 

(a) "Area'' means the area covered by 

the.vertical projection of the pile upon 

the earth's surface. 

(b) "Commission" means the Nuclear 

Regulatory Commission or its 

Agreement Statea (where applicable). 

(c) "Continuous disposal" means a 

method of talllngs management and 

disposal in which tailings are dewatered 

by mechanical methods immediately 

after generation. The dried tailings are 

then placed in trenches or other disposal 

areas and Immediately covered to 

Federal standards. 

(d) "Covered" means to cover with 

earth sufficient to meet Federal 

standards for the management of 

uranium byproduct materials pursuant 

to 40 CFR 192.32. 

(e) "Dewatered" means to remove the 

water from recently produce~ tailings by 

mechanicel or evaporative methods 

such that the water content of the 

tailings does not exceed 30 percent by weight. 

(f) "Existing tailings pile" means a 

tailings pile that is in operation on the 

effective date of this rule. · 

(g) "Ucensed site" means the area 

contained within the boundary of a 

locetion under the control of persons 

generating or storing uranium byproduct 

materials under a li.cense issued by the 

Commission. This includes such areas 

licensed by Agreement States, i.e., those 

States which have entered into an 

effective agreement under Section 274(b) 

of the Atomic Energy Act of 1954, as 

amended. 

(h) "New tailings" means uranium 

tailings produced ~fter the effective date 

of this rule. · 

(i) ·"New tailings impoundment" 

means any location or structure at 

which uranium mill taillngs are 

temporarily or permanently stored and 

which Is placed in operation after the 

promulgation of this rule. 

m "Operation" means that an 

impoundment Is being used for the 

continued placement of new tailings or 

Ia in standby. An impoundment ia In . 

operation from the day that tailings are 

first placed In the impoundment until the 

day that final cloaure begins. 

(k) "Owner" means any person who 

owns or operate& a uranium ~II or an 

exi8tlng tailings pile or a new 

impoundment. 

(1) "Phased disposal" means a method 

of tailings management and disposal 

which uses lined impoundments meeting 

the requirements of 40 CFR Part 192.32, 

no greater than 40 acres In area, wJlich 

immediately filled, upon becoming dried. 

and covered to Federal standards. 

(m) "Uranium byproduct material" or 

"tailings" means the wastes produced 

by the extraction or concentration of 

uranium from any ore processed 

primarily for its source material content. 

Ore bodies depleted by uranium 

solution extractions and which remain 

unde11round do not conatitute 

byproduct material for the purposes of 

this subpart. 

§61.252 Standard. 

(a) All new tailings·impoundments 

built after the effective date of this rule 

shall be designed and constructed to 

meet one of the two following work 

practice standards and in the following . manner: 

(1) Phased disposal in lined tailings 

impoundme.nts that are no more than 40 

acres in area and meet the requirements 

of 40 CPR 192.32(a). The owner shall 

have no more than two impoundments 

in operation at any one site at any one 

time. . · (2) Continuous disposal of tailings 

such that the tailings a.re dewatered and 

immediately disposed with no more than 

10 acres of tailings being uncovered at 

any time and operated in accordance 

with 40 CFR 192.32{a). 

(b) Owners who build new tailings 

impoundments may continue to place 

new tailings or waste water associated 

with milling or mining activities on 

existing tailings piles only until new 

tailing& impoundments are constructed. 

and only if the owner is In the process of 

designing, licensing. and constructing 

new tailings impoundments in 

accordance with the following schedule: 

(1) As soon as practical. but no later 

than 2 years after the effective date of 

this rule, all owners who wish to build 

new taiUngs impoundments shall apply 

to the Administrator for approval to 

construct under section 61.07. The 

Administrator shall make a 

determination to grerit or deny any 

application for approval in accordance 

with section 6t.OS. except that the time 

limitations of subsections (a) and (d) 

shall not apply. · (2) Within 60 days following the 

Administrator's approval to con~Jtruct a 

new tailinga Impoundment. the owner 

shall apply to the Commission for a 

license to construct a new tailings 

Impoundment. 

(S) Following the granting of a license 

by the Commission, the owner shall 

begin construction of the new tailings 

Impoundment within 90 days unless 

seasonal conditions do not permit, In 

which cese construction shall begin at 

the start of the next construction season. 

This impoundment shall be completed 

and shall be ready to receive new . tailings within 30 months of the date of 

licensing by the Commission. 

(4) In no event shall new tailings be 

placed on existing taUings piles after 

December 31, 1992, unless the owner has 

received an exception or extension from 

the Administrator In accordance with 

paragraphs (d) or (e) of this section. 

(c) Owners who do not Intend to build 

a new tailings impoundment must certify . to the Administrator as soon as · 
Federal Register I Vol. 51. No. 185 I Wednesday. September 24, ·1986 .f Rules and Regulations 34067 

possible. but no later than 2 years such time as neither of the two criteria 

following the effective date of this nile. continue to apply. the owner shall so 

that they do not intend to build a new notify the Administrator, and the 

impoundment at the mill site. Owners · exception shall terminate. 

who make this certification will be able . (e) An owner may ·apply to the 

to use their existing· tailings piles for the Administrator on an impoundment-bydeposition of new tailings or waste impoundment basis. for a.n extension to water associated with milling and continue using an existing tailings pile. mining activities until December 31. {1}{1) An extension may be granted 

1992. unless they receive an exception or upon a showing that; despite a good 

extension from the Administrator in faith effort by the owner. it cannot. due 

accordance with paragraph (d) or (e) of to circumstances beyond Its control. 

this section. in which case the owner. meet any paragraph (b) schedu.le 

may continue to use the existing tailings deadline. 

piles as permitted by the terms of the · (ii) An extension may be granted, for 

exception or extension. · any paragraph (b) or (c) schedule 

(d) An exception for continued use of deadline at the Administrator's an existing tailings pile shall be granted discretion. upon a showing by the owner 

upon application for approval to the that the ·extension is consistent with · 

Administrator provided that: protection of the public health with an (1) The existing tailings pile is 40 ample margin of safety. To make this acres or smaller in area and meets the · showing, the owner must first certify 

requirements of 40 CFR 192.32{a)(1), or that" it is in compliance with applicable 

(2) The combined area of all piles at a existing NRC regulations and license 

licensed site Is less than 20 acres. conditions. In addition, the 

The Administrator will grant. grant with Administrator will also take into 

conditions, or deny the application. lf account: the size and condition of the 

granted, the owner mu!lt certify to the pile, the size a~d location of the nearby 

Administrator every S years that it still population. the length of extension 

meets at least one of the preceding requested, the existence and 

criteria. Following. this certification, the effectiveness of any risk reduction 

Administrator will grant, grant with practices that are or will be taken, and 

conditions or deny the exception. At any the expected level of future mill activity. 

(2) The owner may apply for an 

extension at any time up to I year before 

the cease-use date. The Administrator 

will have 9 months from the date of · application to grant. grant with 

conditions or deny the extension: 

Subject to paragraph {g) of this section. 

no extension will be granted for longer 

than 5 .years, and no extension pursuant · to paragraph {e)(l)(i) shalt be granted for 

any period longer than necessary for the owner to meet applicable paragraph (b) 

requirementi. 

{3) The owner may apply for as many 

extensions· as needed. Each extension 

must be applied for and proven 

separately. 

(4) The Administrator will provide for 

public notice and comment on all 

applications for approval of extensions. 

(f) All applications for approval of 

exceptions or extensions shall be sent to 

the Assistant Administrator for Air and 

Radiation {ANR-443), U.S. 

Environmental Protection Agency, 401 M 

Street, SW., Washington.. DC 20460. 

(g) New tailings shall not be placed on any existing tailings pile after December 

31, 2001, and no ·exception or extension shall be effective after that date. 

· [FR Doc. 88-20193 Filed 9-23-88; 8:45 am} 

IILLIHO COD£~