[Federal Register Volume 64, Number 22 (Wednesday, February 3, 1999)]
[Rules and Regulations]
[Pages 5574-5580]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-2545]



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Part VII





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 61



National Emission Standard for Hazardous Air Pollutants: National 
Emission Standards for Radon Emissions From Phosphogypsum Stacks; Final 
Rule

  Federal Register / Vol. 64, No. 22 / Wednesday, February 3, 1999 / 
Rules and Regulations  

[[Page 5574]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 61

[FRL-6229-4]
RIN 2060-AF04


National Emission Standard for Hazardous Air Pollutants; National 
Emission Standards for Radon Emissions From Phosphogypsum Stacks

AGENCY: Environmental Protection Agency.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (EPA) is promulgating 
revisions to the National Emission Standard for Hazardous Air 
Pollutants (NESHAP) that sets limits on radon emissions from 
phosphogypsum stacks, codified as subpart R of 40 CFR part 61. The 
Agency is taking today's action in response to a petition for 
reconsideration from The Fertilizer Institute (TFI), which critiqued 
the risk assessment EPA performed in support of the version of subpart 
R promulgated in 1992. Today's action raises the limit on the quantity 
of phosphogypsum that may be used for indoor research and development 
from 700 to 7,000 pounds, eliminates current sampling requirements for 
phosphogypsum used in indoor research and development, and clarifies 
sampling procedures for phosphogypsum removed from stacks for other 
purposes.

DATES: These regulations are effective April 5, 1999. Petitions for 
judicial review of this final action must be filed no later than April 
5, 1999.

ADDRESSES: Copies of the two documents entitled ``Risk Assessment for 
Research and Development Uses of Phosphogypsum'' and ``Statistical 
Procedures for Certifying Phosphogypsum for Entry into Commerce'' may 
be obtained by writing to this address. A summary of comments received 
on the proposed rule accompanied by the Agency's responses may be 
obtained by requesting the response to comment document entitled 
``Comments and Response to Comments--NESHAPS; National Emission 
Standards of for Radon Emissions from Phosphogypsum Stacks on 
Amendments to Subpart R.''

FOR FURTHER INFORMATION CONTACT: Pat Tilson; telephone number (202) 
564-9762; address: Radiation Protection Division, Mail Code 6602J, U.S. 
Environmental Protection Agency, Washington, DC 20460; email address: 
[email protected].

SUPPLEMENTARY INFORMATION:

Docket

    Docket No. A-79-11 contains the public record supporting the final 
rule revising 40 CFR Part 61, Subpart R, which EPA issued in 1992 (57 
FR 23305, June 3, 1992). It also contains the August 3, 1992, TFI 
petition, and the EPA response partially granting and partially denying 
the TFI petition (59 FR 14040, March 24, 1994). Docket No. A-94-57 
contains certain documents which led to the May 8, 1996, proposal and 
this final rulemaking. These dockets are available for public 
inspection between the hours of 8 a.m. and 5 p.m., Monday through 
Friday, in room M1500 of Waterside Mall, 401 M Street, SW, Washington, 
DC 20460. A reasonable fee may be charged for copies of documents.

Introduction

Purpose of Today's Action and Summary of Changes to Subpart R

    The Agency is promulgating revisions to those portions of Subpart R 
of 40 CFR part 61 which concern: (1) the distribution and use of the 
substance, phosphogypsum, for indoor research and development purposes; 
(2) the sampling and measurement of radium-226 in phosphogypsum; and 
(3) use of phosphogypsum for outdoor agricultural purposes. The 
Environmental Protection Agency is taking today's action in response to 
issues raised in a petition for reconsideration from The Fertilizer 
Institute which questioned aspects of the risk assessment EPA performed 
in support of the rulemaking that revised Subpart R in 1992. The risk 
assessment was an evaluation of the risk to persons who perform 
research and development activities in a laboratory using 
phosphogypsum. Phosphogypsum--a byproduct of the wet-acid process of 
producing phosphoric acid from phosphate rock--contains naturally 
occurring radiation emitted by uranium-238 and its decay products such 
as radium-226 and radon-222. Exposure to the radiation emitted by these 
and other radionuclides in phosphogypsum can increase an individual's 
probability of developing cancer. If present in quantities above 
certain limits, the radionuclides in phosphogypsum could cause 
unacceptable risks of incurring fatal cancer.
    Specifically, today's action revises Sec. 61.205 to conform to the 
technical findings EPA made when it re-evaluated the risk assessment 
used to promulgate Subpart R in 1992. See 57 FR 23305, June 3, 1992. 
EPA found that the risk assessment contained errors in the calculation 
of the quantity of the radioactive gas, radon-222, that would be 
present in a laboratory in which phosphogypsum was used for indoor 
research and development purposes. Today's action revises the limit set 
by Subpart R on the amount of phosphogypsum that may be used in indoor 
research and development from 700 pounds upward to 7,000 pounds. In 
addition, today's action provides clarification on how to determine 
compliance with the new, 7,000-pound limit, such as whether this limit 
should be applied on a facility-by-facility or on an experiment-by-
experiment basis.
    In addition, the Agency is removing the requirement to sample and 
measure the radium-226 in phosphogypsum that is used for indoor 
research and development activities because Subpart R does not contain 
a corresponding limit on the concentration of radium-226 in 
phosphogypsum when it is used for these activities. Sampling of radium-
226 concentrations must still be performed when phosphogypsum is used 
for outdoor agricultural purposes, as set forth in Sec. 61.204, and 
when application is made to EPA for approval to use phosphogypsum for 
other purposes pursuant to Sec. 61.206. Today's action makes minor 
changes to Secs. 61.204 and 61.205 to draw the distinction more sharply 
between the uses of phosphogypsum which are covered by the respective 
sections.
    In addition, the Agency is revising section 61.207 to establish the 
level of statistical uncertainty that is allowed in measurements of 
radium-226 in phosphogypsum. These measurements are performed in 
connection with outdoor agricultural uses of phosphogypsum and those 
other uses of phosphogypsum that the Agency approves on a case-by-case 
basis.

History of the NESHAP for Phosphogypsum and TFI's Petition for 
Reconsideration

    EPA first promulgated the NESHAP for phosphogypsum stacks on 
December 15, 1989. At that time, the standard required that all 
phosphogypsum be disposed of in stacks. Phosphogypsum stacks are large, 
on-site disposal piles composed of the excess phosphogypsum formed 
during the wet-acid process. Unlike subsequent versions of Subpart R, 
the 1989 standard did not permit alternate uses of phosphogypsum such 
as for indoor research and development.
    EPA subsequently received several petitions requesting that it 
reconsider setting standards that would permit alternatives to disposal 
of phosphogypsum in stacks. Petitioners argued that EPA had not 
considered the

[[Page 5575]]

implications of these alternatives when it set the 1989 rule. EPA 
agreed to convene a rulemaking to evaluate the attendant risks of these 
alternatives to disposal and establish standards under which these 
alternatives might be permissible. See 55 FR 13480, April 10, 1990. EPA 
promulgated revisions to Subpart R after analyzing the associated risks 
of alternate uses and evaluating the comments received on the proposed 
rule. See 57 FR 23305, June 3, 1992. The revised Subpart R permitted 
uses of phosphogypsum that fall into three categories: (1) Outdoor 
agricultural uses, for example as a conditioner for soils containing 
high quantities of salt or low quantities of calcium and other 
nutrients; (2) indoor research and development activities, for example 
to study the production of road-base and building materials using 
phosphogypsum; and (3) other alternate uses that are approved by EPA on 
a case-by-case basis.
    Subsequently, TFI sought judicial review of the 1992 rule in The 
Fertilizer Institute v. Environmental Protection Agency, No. 92-1320 
(D.C. Cir.). TFI also filed a petition with EPA on August 3, 1992, 
requesting EPA to reconsider the 1992 rule pursuant to section 
307(d)(7)(B). A second suit was brought against the Agency by ManaSota-
88 in ManaSota-88 v. Browner, No. 92-1330 (D.C. Circuit). EPA entered 
settlement discussions with TFI and ManaSota-88, and agreed jointly to 
move the D.C. Circuit Court of Appeals to stay judicial review of the 
1992 rule. The Court granted the motion. As part of that agreement, EPA 
agreed to make a final decision whether to grant or deny TFI's petition 
for reconsideration. EPA decided to partially deny and partially grant 
the petition after careful review of all the objections to the 1992 
rule set forth in the petition for reconsideration. See 59 FR 14040, 
March 24, 1994. The principal purpose of the present rulemaking is to 
effectuate the decision by EPA to partially grant the TFI petition.

Statutory Basis and the Benzene Policy

    EPA initially promulgated the NESHAP for phosphogypsum stacks on 
December 15, 1989 pursuant to Section 112 of the Clean Air Act (CAA). 
In 1990, Section 112 was amended by the Clean Air Act Amendments of 
1990. Section 112(q)(2) of the CAA, as amended, specifically provides 
that Section 112 of the CAA shall remain in effect for, inter alia, 
radionuclide emissions from phosphogypsum stacks.
    Under the CAA, as in effect prior to enactment of the Clean Air Act 
Amendments of 1990, the Agency, in establishing risk-based standards, 
must follow the method specified in the ``Vinyl Chloride decision.'' 
Natural Resources Defense Council v. EPA, 824 F.2d 1146 (D.C. Cir. 
1987). The Vinyl Chloride decision requires that these Section 112 
standards be established in two steps. In the first step, the Agency 
determines a ``safe'' or ``acceptable'' level of risk by considering 
only health-related factors. Next, the Agency may make the standard 
more protective considering costs and technological feasibility. The 
resulting standard must protect public health with an ample margin of 
safety.
    EPA implemented the Vinyl Chloride decision in 1989 with the 
promulgation of the NESHAP for benzene. This rulemaking established the 
``Benzene Policy'' by which EPA sets standards under Section 112 of the 
Clean Air Act, as in effect prior to enactment of the Clean Air Act 
Amendments of 1990. See 54 FR 38044 (September 14, 1989). The Benzene 
Policy sets forth the specific criteria EPA uses when determining the 
safe level of risk set by NESHAPs. Any amendments or revisions to the 
existing NESHAP for phosphogypsum would have to meet these criteria for 
the Agency to consider it adequately protective of public health with 
an ample margin of safety. Included among these criteria is the 
requirement that NESHAPs protect the individual receiving the highest 
lifetime risk to a level of 1 in 10,000.

Description of the Final Rule

    Today's action affects those portions of Subpart R which cover the 
use of phosphogypsum in indoor research and development found at 
Sec. 61.205 and the procedures for sampling and measurement of radium-
226 in phosphogypsum found at Sec. 61.207. In addition, today's 
rulemaking revises Sec. 61.204 to clarify that agricultural uses that 
occur in an indoor laboratory must comply with Sec. 61.205, while 
outdoor agricultural uses of phosphogypsum must comply with 
Sec. 61.204.

The New 7,000 Pound Limit on Indoor Research and Development Uses

    Today's action raises the limit set by Sec. 61.205(b)(2) on the 
amount of phosphogypsum that may be used in indoor research and 
development from 700 pounds to 7,000 pounds. The Agency is revising the 
limit to conform to the technical findings it made when it re-evaluated 
the risk assessment used to promulgate Subpart R in 1992. Specifically, 
EPA found that the risk assessment contained errors in the calculation 
of the quantity of the radioactive gas, radon-222, that would be 
present in a laboratory in which phosphogypsum was being used for 
research and development purposes. EPA has revised three of the key 
assumptions used in these calculations. A complete discussion of the 
changed parameters and the effect of these changes on the presence of 
radon-222 are contained in the document, ``Risk Assessment of Research 
and Development Uses of Phosphogypsum.'' First, EPA revised the 
assumption made regarding the number of drums of phosphogypsum that 
would be opened at any one time and from which radon-222 could 
therefore escape to the ambient air in the laboratory. During the 1992 
rulemaking, EPA's risk assessment assumed that five such drums would be 
open. EPA changed this assumption to reflect that at most only one 
single drum would be open under actual conditions in laboratories. 
Public comments on the notice of proposed rulemaking noted that 
laboratories typically use phosphogypsum a few pounds at a time, making 
it unnecessary to have several drums open simultaneously.
    Second, EPA changed the assumption regarding how much of the radon-
222 that is present in the phosphogypsum actually emanates into the 
ambient air of the laboratory. When setting the 1992 rule, EPA had 
assumed that all the radon-222 generated by the radium-226 in 
phosphogypsum would be released. EPA's new risk assessment reconsiders 
such factors as the rate at which air is ventilated from a laboratory, 
the size of the laboratory and the effect of moisture on the rate of 
emanation of radon-222 from the phosphogypsum.
    Third, EPA revised the assumption on the number of hours a 
researcher spends in the laboratory from 4,000 hours down to 1,000 
hours per year. The value of 4,000 hours that was used in the 1992 
rulemaking exceeded by 100 percent the typical occupational year of 
2,000 hours. The value of 1,000 hours was judged to be a more realistic 
estimate.
    By making these three changes and re-calculating the risk, EPA 
found that the use of 7,000 pounds of phosphogypsum for indoor research 
and development purposes would cause a risk that was just slightly 
higher than 1 in 100,000. It was apparent that revising the regulation 
so as to permit 7,000 pounds of phosphogypsum would still meet the 
presumptively safe risk level of 1 in 10,000 that EPA established with 
the Benzene Policy.
    EPA requested public comment on what practical advantages a higher 
limit of 7,000 pounds would provide in the Notice of Proposed 
Rulemaking (61 FR 20775, May 8, 1996). The comments received by the 
Agency indicated that

[[Page 5576]]

the higher limit would permit larger scale experiments yielding results 
which can be applied more accurately to real uses of phosphogypsum. 
Comments also stated that the higher limit would permit a facility to 
keep phosphogypsum in one large, 7,000-pound storage area rather than 
in several smaller separate storage areas associated with each 
individual experiment or activity. (For more on how to apply the 7,000-
pound limit, see discussion below on how regulated parties should 
determine if individual laboratories and experiments are in 
compliance.) Further comments stated that the health risk corresponding 
to 7,000 pounds of phosphogypsum was acceptable, especially given the 
view that EPA's conservative choice of parameter values (e.g., hours 
spent inside a laboratory) led to over-estimates of the risk to persons 
doing research. Other comments expressed concern, however, that doses 
to persons performing radium extraction might be higher than in routine 
handling in other indoor research and development. EPA's revised risk 
assessment nonetheless shows that even handling the large amounts of 
phosphogypsum required for extracting radium would not cause risks in 
excess of the 1 in 10,000 level set by the Benzene Policy, provided 
that the 7,000-pound limit was not exceeded. Based on the public 
comments received and the findings of EPA's revised risk assessment, 
EPA is amending the limit on the amount of phosphogypsum to 7,000 
pounds. For further discussion of the revised risk assessment, see the 
document, ``Risk Assessment of Research and Development Uses of 
Phosphogypsum.''

How to Determine Compliance With the 7,000-Pound Limit

    Today's action revises Sec. 61.205(b)(2) to clarify how compliance 
is determined with the 7,000 pound limit. Both TFI's petition and many 
public comments on the notice of proposed rulemaking (61 FR 20775, May 
8, 1996) expressed confusion over whether this limit applies to one 
room (i.e., a ``laboratory''), an entire building, etc. In other words, 
is the correct method for determining compliance to add up the total 
pounds of phosphogypsum in use, everywhere for all experiments and 
rooms in a facility, and testing this total against the 7,000-pound 
limit? Or should compliance be determined by separately comparing the 
phosphogypsum used in each experiment and/or room to the 7,000-pound 
limit?
    The Agency first evaluated the health risk implied by each of the 
above two methods of determining compliance. The risk assessment 
examined whether a person working in a facility that had several 
ongoing projects of 7,000 pounds would experience greater risk than a 
person working in a facility having only one such project. The risk 
breaks down to the sum of two types of radiation risks: (1) the risk 
from direct gamma radiation; and (2) the risk from inhaled radon which 
is generated by the presence of radium-226. With respect to gamma 
radiation, the risk assessment assumes that the researcher is exposed 
to 10 drums (7,000 pounds) in the same room for 1,000 hours, at a 
distance of one meter. A researcher might receive additional gamma 
radiation if any other experiments were taking place elsewhere in the 
building. EPA's risk assessment considered this latter possibility. The 
effect of gamma radiation from these additional rooms would, however, 
be substantially decreased the further away a person is located from 
the source. Hence, EPA's risk assessment found that the researcher 
would for the most part only be affected by the gamma radiation from 
the drums in the room he is standing in. The risk due to gamma 
radiation would effectively remain unchanged with either way of 
determining compliance with the 7,000-pound limit.
    The second component of risk, the inhalation of radon-222, would 
not increase if additional experiments took place in nearby rooms 
within the same building. This results from the fact that the air in 
rooms where separate experiments occur would effectively remain 
isolated; the radon-222 in one room would not migrate to other rooms 
and increase the radon-222 concentration found within the other rooms. 
The combined risk from gamma radiation and inhaled radon-222 
effectively would be the same whether the limit applied separately to 
the different projects within a facility or if it limited the total 
phosphogypsum from all research activities within a research complex to 
7,000 pounds. A more in-depth discussion is contained in ``Risk 
Assessment for Research and Development Uses of Phosphogypsum.''
    Based on the findings of the risk assessment and public comments 
received on the notice of proposed rulemaking, EPA revised 
Sec. 61.205(b)(2) of Subpart R so that the 7,000-pound limit applies 
separately to each individual research and development activity. In 
addition, no more than 7,000 pounds may be stored in any room at a 
research and development facility. Thus, a particular facility may 
purchase or possess more than 7,000 pounds of phosphogypsum for use in 
multiple research activities, so long as it does not exceed this limit 
for any individual research activity and no one room within the 
facility contains more than this limit.

Difference in Applicability Between Sections 61.204 and 61.205

    EPA is revising Sec. 61.205(b)(5) to clarify that research and 
development activities authorized by this section must occur indoors in 
a controlled laboratory setting that the public cannot enter freely, 
except on an infrequent basis for tours of the facility. In addition, 
EPA is revising the title of Sec. 61.205 to indicate that this section 
applies to indoor research and development. EPA is making these 
revisions in response to both TFI's petition and public comments. These 
parties expressed uncertainty as to which section of Subpart R would 
apply to agricultural uses of phosphogypsum that are conducted for the 
purpose of research and development. To this end, EPA has added 
clarifying language to Sec. 61.205(b)(5) of the final rule that 
specifies that outdoor agricultural research and development must 
comply with Sec. 61.204, on outdoor agricultural uses. As a compliment 
to this new language, EPA has added language to Sec. 61.204 to specify 
that agricultural research and development that occurs indoors, in a 
laboratory, must comply with Sec. 61.205, on indoor research and 
development in a laboratory.
    To summarize, outdoor uses of phosphogypsum must comply with either 
Sec. 61.204, ``Distribution and use of phosphogypsum for outdoor 
agricultural purposes'' or Sec. 61.206, ``Distribution and use of 
phosphogypsum for other purposes.'' Section 21.206 allows EPA to 
authorize, on a case-by-case basis, indoor and outdoor uses not covered 
or authorized by Secs.  61.204 and 61.205. Phosphogypsum that remains 
in outdoor stacks must comply with the numerical limits of Sec. 61.202.

Situations in Which Sampling of Radium-226 is Required

    Today's action removes the portions of Secs. 61.205(a) and 
61.207(a) requiring sampling of phosphogypsum that is to be used for 
indoor research and development activities. TFI's petition and many 
public comments on the notice of proposed rulemaking noted that Subpart 
R does not establish any limit on the concentration of radium-226 in 
phosphogypsum used pursuant to Sec. 61.205, only on the number of 
pounds that are used. Hence, these parties noted that the existing 
requirement on sampling would merely add hundreds of dollars of cost 
without

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increasing the assurance that public health is being protected with an 
ample margin of safety.
    By removing this requirement, EPA will not change the level of 
protection afforded to persons who perform indoor research and 
development. The risk assessment EPA performed on indoor research and 
development assumed that the phosphogypsum would have a very high 
concentration of radium-226 (equal to 26 pCi/g) and set a pound limit 
appropriate to this assumption. This high level of radium-226 
represents the radium concentration found in the most radioactive 
phosphogypsum stacks, which are in Florida. The 7,000-pound limit 
controls the radiological cancer risk because it has the effect of 
limiting the total quantity of radium-226 that is present.
    Sampling of radium-226 concentrations must nonetheless still be 
performed when phosphogypsum is used for outdoor agricultural purposes, 
as set forth in Sec. 61.204, and when application is made to EPA under 
Sec. 61.206 for approval of phosphogypsum use for other purposes.

Procedures for Sampling and Measurement of Radium-226

    The Agency is substantially revising Sec. 61.207, on sampling and 
measurement of phosphogypsum, to clarify what levels of statistical 
uncertainty are allowable in measurements of radium-226 in 
phosphogypsum. The 1992 rule established the requirement for 
measurement and sampling of phosphogypsum used for outdoor agricultural 
uses under Sec. 61.204 and for ``other uses'' under Sec. 61.206. TFI's 
petition and the public comments on the notice of proposed rulemaking 
noted that the 1992 rule did not specify the allowable uncertainties. 
Today's action provides clarification on the statistical method that 
must be followed to establish this statistical uncertainty.
    The following discussion relies on several statistical terms. 
Critical value means the percentile value, , of a probability 
distribution above or below which only  per cent of the 
probability lies. Thus there is a .05 probability that a normally 
distributed variable will have a value above the upper 5% critical 
value, which is calculated by summing the product of 1.64 times the 
standard deviation of the distribution to the mean of the distribution. 
When testing an hypothesis,  is the level of significance, and 
determines the critical value.
    Hypothesis testing means a procedure for the statistical 
determination of the validity of an hypothesis. A test statistic, such 
as the standard normal variable, is calculated for the purpose of 
discriminating between a null hypothesis and an alternative.
    Level of significance means the probability,  of rejecting 
the null hypothesis in a test of an hypothesis.
    Sampling distribution means a probability distribution assumed by a 
statistic such as the sample mean, calculated from a sample drawn from 
a population.
    Under this final rule, the procedure for certifying an area of a 
phosphogypsum stack for entry into commerce requires the collection of 
samples of phosphogypsum and the measurement of their radium-226 
content. The samples must be collected from regularly spaced locations 
across the area of the stack being considered for entry into commerce. 
After the radium-226 concentration in each sample is measured, the mean 
and standard deviation of the collected samples must be calculated.
    A decision rule, based on the sampling distribution for the sample 
mean, must be used to determine if the phosphogypsum is acceptable for 
entry into commerce. This rule requires the determination of the 
critical value for a 5% level of significance in the upper, or right 
hand, tail of the sampling distribution. The critical value is the 95th 
percentile of the sampling distribution.
    The decision rule has three outcomes. If the critical value is less 
than or equal to 10 pico-curies per gram (pCi/g), phosphogypsum from 
this area of the stack can be entered into commerce. (By definition, 
one curie of a given radionuclide experiences 37 billion nuclear decays 
per second. A pico-curie (pCi) is one trillionth of one curie.) If the 
mean of the collected samples is greater than or equal to10 pCi/g, 
phosphogypsum from this area of the stack cannot be entered into 
commerce. If the sample mean is less than 10 pCi/g and the critical 
value is greater than 10 pCi/g, the phosphogypsum cannot be entered 
into commerce unless further testing is undertaken. The sample size 
must be increased, and the sample mean and standard deviation 
recalculated. The increased sample size reduces the standard deviation 
of the sampling distribution of the mean, thereby, reducing the 
interval between the mean of the sampling distribution and the critical 
value. This increases the ability of the decision rule to distinguish 
between the mean of the sample and the 10 pCi/g concentration limit, 
thereby improving the chance that the radium-226 concentration can be 
shown to be less than 10 pCi/g.
    The reason for determining the critical value for the upper, or 
right hand, tail of the sampling distribution is the concern that the 
radium-226 concentration in the phosphogypsum not be greater than 10 
pCi/g.
    If a larger sample size is needed to demonstrate that the sample 
mean is less than 10 pCi/g, the number of additional samples required 
increases rapidly as the mean approaches 10 pCi/g, and can be quite 
large in cases where the sample mean is only slightly less than 10 pCi/
g. In such cases the additional cost of certification may become a 
factor in the decision to continue with the attempt to enter the 
phosphogypsum from this area of the stack into commerce.
    Any required additional samples must also be taken from regularly 
spaced locations across the area of the phosphogypsum stack being 
considered for entry into commerce. Once the required number of 
additional samples have been collected, the radium-226 concentrations 
in each additional sample must be measured. The mean and standard 
deviation of the radium-226 concentrations for the entire set of sample 
concentrations (including those previously measured) must be 
recalculated and a new sampling distribution established. The critical 
value for a 5% level of significance in the upper tail is established 
once again. The decision rule must then be revisited. As before, 
phosphogypsum from this area of the stack can be entered into commerce 
only if the critical value is less than or equal to 10 pCi/g.
    Although acceptance for entry into commerce is the objective of 
increasing the sample size and establishing the new sampling 
distribution and critical value, and is the expected outcome of the 
reconsideration, it is possible the recalculated critical value will 
not be less than or equal 10 pCi/g. This is because random variation in 
the new sample concentrations, which can result from nonuniformity in 
the distribution of radium-226 in the phosphogypsum and the random 
nature of radioactive decay, may cause an increased sample mean or 
standard deviation. Either or both of these increases can change the 
critical value so that it is not less than 10 pCi/g. If this is the 
case, either the sample size must be increased once again, and a new 
sampling distribution and critical value determined, or the attempt to 
certify that area of the stack for entry into commerce must be 
abandoned.

[[Page 5578]]

Judicial Review

    This rulemaking action promulgates revisions of a national standard 
issued under Clean Air Act Section 112, 42 U.S.C. 7412. Any petition 
for judicial review of this action must be filed no later than April 5, 
1999 in the United States Court of Appeals for the District of Columbia 
Circuit. Under Section 307(d)(7)(B) of the Clean Air Act, only those 
objections to this rule which were raised with reasonable specificity 
during the period for public comment or at the public hearing may be 
raised as part of such judicial review.

Regulatory Analyses

Regulatory Flexibility Act

    EPA has determined that it is not necessary to prepare a regulatory 
flexibility analysis in connection with this rule under section 605(b) 
of the Regulatory Flexibility Act, 5 U.S.C. 605(b). EPA has further 
determined that this final rule will not have a significant economic 
impact on a substantial number of small entities. Small entities 
include small businesses, small not-for-profit enterprises, and small 
governmental jurisdictions. Today's rule will have a positive economic 
impact on the great majority of entities regulated by subpart R, 
including small businesses. Specifically, this rule will allow greater 
quantities of phosphogypsum to be used and reduce costs of 
demonstrating compliance by removing certain regulatory requirements. 
No new restrictions, exclusions or limitations are being added. As 
such, this rule will lessen the regulatory burden on regulated 
entities, including small entities, which existed prior to today's 
action.

Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. 
L. 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local and tribal 
governments and the private sector. Today's final action contains no 
Federal mandates (under the regulatory provisions of Title II of UMRA) 
for State, local or tribal governments or the private sector.

Paperwork Reduction Act

    There are no information collection requirements in this final 
rule.

Review Under Executive Order 12866

    Under Executive Order 12866, 58 FR 51736 (October 4, 1993), EPA 
must determine whether a regulation is ``significant'' and therefore 
subject to review by the Office of Management and Budget. The Order 
defines ``significant regulatory action'' as one that is likely to 
result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    EPA has determined that this action does not meet any of the 
criteria enumerated above, and therefore does not constitute a 
``significant regulatory action'' under the terms of the Order.

Executive Order 13045: Protection of Children From Environmental Health 
Risks and Safety Risks

    Executive Order 13045 applies to any rule that: (1) is determined 
to be ``economically significant'' as defined under E.O. 12866, and (2) 
concerns an environmental health or safety risk that EPA has reason to 
believe may have a disproportionate effect on children. If the 
regulatory action meets both criteria, the Agency must evaluate the 
environmental health or safety effects of the planned rule on children, 
and explain why the planned regulation is preferable to other 
potentially effective and reasonably feasible alternatives considered 
by the Agency.
    This rule is not subject to E.O. 13045 because it is not an 
economically significant rule as defined by E.O. 12866, and because it 
does not involve decisions on environmental health or safety risks that 
may disproportionately affect children.

Executive Order 12875: Enhancing the Intergovernmental Partnership

    Under Executive Order 12875, EPA may not issue a regulation that is 
not required by statute and that creates a mandate upon a State, local 
or tribal government, unless the Federal government provides the funds 
necessary to pay the direct compliance costs incurred by those 
governments, or EPA consults with those governments. If EPA complies by 
consulting, Executive Order 12875 requires EPA to provide to the Office 
of Management and Budget a description of the extent of EPA's prior 
consultation with representatives of affected State, local and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create a mandate on State, local or tribal 
governments. The rule does not impose any enforceable duties on these 
entities. Accordingly, the requirements of section 1(a) of Executive 
Order 12875 do not apply to this rule.

Executive Order 13084: Consultation and Coordination With Indian Tribal 
Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected and other representatives of 
Indian tribal governments ``to provide meaningful and timely input in 
the development of regulatory policies on matters that significantly or 
uniquely affect their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. Accordingly, the requirements 
of section 3(b) of Executive Order 13084 do not apply to this rule.

The National Technology Transfer and Advancement Act 2 of 1995 (NTTAA)

    The National Technology Transfer and Advancement Act of 1995 
(NTTAA), Section 12(d) of Pub L. No. 104-113, is designed to encourage 
the

[[Page 5579]]

adoption of standards developed by ``voluntary consensus bodies'' in 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs 
agencies to provide Congress, through OMB, explanations when a decision 
is made not to use available and applicable voluntary consensus 
standards.
    This action does not involve technical standards. Therefore, EPA 
did not consider the use of any voluntary consensus standards.

The Congressional Review Act (CRA)

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, U.S. House of Representatives, 
and the Comptroller General of the United States prior to publication 
of the rule in the Federal Register. A major rule cannot take effect 
until 60 days after it is published in the Federal Register. This 
action is not a ``major rule'' as defined by 5 U.S.C. 804(2). This rule 
will be effective April 5, 1999.

List of Subjects in 40 CFR Part 61

    Environmental protection, Air pollution control, Phosphogypsum, 
Radon, Radium.

    Dated: January 27, 1999.
Carol Browner,
Administrator.

    For the reasons set forth in the preamble, the Environmental 
Protection Agency amends 40 CFR part 61 as follows:

PART 61--[AMENDED]

    1. The authority citation for part 61 continues to read as follows:

    Authority: 42 U.S.C. 7401, 7412, 7413, 7416, 7601 and 7602.

Subpart R--National Emission Standards for Radon Emissions From 
Phosphogypsum Stacks

    2. Amend Sec. 61.204 by revising the section title, introductory 
text, paragraph (c), paragraph (d), and adding paragraph (e) to read as 
follows:


Sec. 61.204  Distribution and use of phosphogypsum for outdoor 
agricultural purposes.

    Phosphogypsum may be lawfully removed from a stack and distributed 
in commerce for use in outdoor agricultural research and development 
and agricultural field use if each of the following requirements is 
satisfied:
* * * * *
    (c) All phosphogypsum distributed in commerce for use pursuant to 
this section by the owner or operator of a phosphogypsum stack shall be 
accompanied by a certification document which conforms to the 
requirements of Sec. 61.208(a).
    (d) Each distributor, retailer, or reseller who distributes 
phosphogypsum for use pursuant to this section shall prepare 
certification documents which conform to the requirements of 
Sec. 61.208(b).
    (e) Use of phosphogypsum for indoor research and development in a 
laboratory must comply with Sec. 61.205.
    3. Amend Sec. 61.205 by revising the section title and paragraphs 
(a) and (b) to read as follows:


Sec. 61.205  Distribution and use of phosphogypsum for indoor research 
and development.

    (a) Phosphogypsum may be lawfully removed from a stack and 
distributed in commerce for use in indoor research and development 
activities, provided that it is accompanied at all times by 
certification documents which conform to the requirements of 
Sec. 61.208. In addition, before distributing phosphogypsum to any 
person for use in indoor research and development activities, the owner 
or operator of a phosphogypsum stack shall obtain from that person 
written confirmation that the research facility will comply with all of 
the limitations set forth in Sec. 61.206(b).
    (b) Any person who purchases and uses phosphogypsum for indoor 
research and development purposes shall comply with all of the 
following limitations. Any use of phosphogypsum for indoor research and 
development purposes not consistent with the limitations set forth in 
this section shall be construed as unauthorized distribution of 
phosphogypsum.
    (1) Each quantity of phosphogypsum purchased by a facility for a 
particular research and development activity shall be accompanied by 
certification documents which conform to the requirements of 
Sec. 61.208.
    (2) No facility shall purchase or possess more than 7,000 pounds of 
phosphogypsum for a particular indoor research and development 
activity. The total quantity of all phosphogypsum at a facility, as 
determined by summing the individual quantities purchased or possessed 
for each individual research and development activity conducted by that 
facility, may exceed 7,000 pounds, provided that no single room in 
which research and development activities are conducted shall contain 
more than 7,000 pounds.
    (3) Containers of phosphogypsum used in indoor research and 
development activities shall be labeled with the following warning: 
Caution: Phosphogypsum Contains Elevated Levels of Naturally Occurring 
Radioactivity.
    (4) For each indoor research and development activity in which 
phosphogypsum is used, the facility shall maintain records which 
conform to the requirements of Sec. 61.209(c).
    (5) Indoor research and development activities must be performed in 
a controlled laboratory setting which the general public cannot enter 
except on an infrequent basis for tours of the facility. Uses of 
phosphogypsum for outdoor agricultural research and development and 
agricultural field use must comply with Sec. 61.204.
* * * * *
    4. Section 61.207 is revised to read as follows:


Sec. 61.207  Radium-226 sampling and measurement procedures.

    (a) Before removing phosphogypsum from a stack for distribution in 
commerce pursuant to Sec. 61.204, or Sec. 61.206, the owner or operator 
of a phosphogypsum stack shall measure the average radium-226 
concentration at the location in the stack from which phosphogypsum 
will be removed. Measurements shall be performed for each such location 
prior to the initial distribution in commerce of phosphogypsum removed 
from that location and at least once during each calendar year while 
distribution of phosphogypsum removed from the location continues.
    (1) A minimum of 30 phosphogypsum samples shall be taken at 
regularly spaced intervals across the surface of the location on the 
stack from which the phosphogypsum will be removed. Let n1 
represent the number of samples taken.
    (2) Measure the radium-226 concentration of each of the 
n1 samples in accordance with the analytical procedures 
described in 40 CFR part 61, appendix B, Method 114.
    (3) Calculate the mean, x1, and the standard deviation, 
s1, of the n1 radium-226 concentrations:

[[Page 5580]]

[GRAPHIC] [TIFF OMITTED] TR03FE99.054


Where x1 and s1 are expressed in pCi/g.

    (4) Calculate the 95th percentile for the distribution, 
x*, using the following equation:
[GRAPHIC] [TIFF OMITTED] TR03FE99.055

Where x* is expressed in pCi/g.

    (5) If the purpose for removing phosphogypsum from a stack is for 
distribution to commerce pursuant to Sec. 61.206, the owner or operator 
of a phosphogypsum stack shall report the mean, standard deviation, 
95th percentile and sample size. If the purpose for removing 
phosphogypsum from a stack is for distribution to commerce pursuant to 
Sec. 61.204, the additional sampling procedures set forth in paragraphs 
(b) and (c) of this section shall apply.
    (b) Based on the values for x1 and x* 
calculated in paragraphs paragraphs (a)(3) and (4) of this section, 
determine which of the following conditions will be met:
    (1) If x1 < 10 pCi/g and x*  10 pCi/g; 
phosphogypsum may be removed from this area of the stack for 
distribution in commerce pursuant to Sec. 61.204.
    (2) If x1, < 10 pCi/g and x* > 10 pCi/g, the owner or 
operator may elect to follow the procedures for further sampling set 
forth in paragraph (c) of this section:
    (3) If x1  10 pCi/g; phosphogypsum shall not 
be removed from this area of the stack for distribution in commerce 
pursuant to Sec. 61.204.
    (c) If the owner or operator elects to conduct further sampling to 
determine if phosphogypsum can be removed from this area of the stack, 
the following procedure shall apply. The objective of the following 
procedure is to demonstrate, with a 95% probability, that the 
phosphogypsum from this area of the stack has a radium-226 
concentration no greater than 10 pCi/g. The procedure is iterative, the 
sample size may have to be increased more than one time; otherwise the 
phosphogypsum cannot be removed from this area of the stack for 
distribution to commerce pursuant to Sec. 61.204.
    (1)(i) Solve the following equation for the total number of samples 
required:
[GRAPHIC] [TIFF OMITTED] TR03FE99.056

    (ii) The sample size n2 shall be rounded upwards to the 
next whole number. The number of additional samples needed is 
nA = n2-n1.
    (2) Obtain the necessary number of additional samples, 
nA, which shall also be taken at regularly spaced intervals 
across the surface of the location on the stack from which 
phosphogypsum will be removed.
    (3) Measure the radium-226 concentration of each of the 
nA additional samples in accordance with the analytical 
procedures described in 40 CFR part 61, appendix B, Method 114.
    (4) Recalculate the mean and standard deviation of the entire set 
of n2 radium-226 concentrations by joining this set of 
nA concentrations with the n1 concentrations 
previously measured. Use the formulas in paragraph (a)(3) of this 
section, substituting the entire set of n2 samples in place 
of the n1 samples called for in paragraph (a)(3) of this 
section, thereby determining the mean, x2, and standard 
deviation, s2, for the entire set of n2 
concentrations.
    (5) Repeat the procedure described in paragraph (a)(4) of this 
section, substituting the recalculated mean, x2, for 
x1, the recalculated standard deviation, s2, for 
s1, and total sample size, n2, for n1.
    (6) Repeat the procedure described in paragraph (b) of this 
section, substituting the recalculated mean, x2 for 
x1.

[FR Doc. 99-2545 Filed 2-2-99; 8:45 am]
BILLING CODE 6560-50-P