[Federal Register Volume 59, Number 57 (Thursday, March 24, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5993]
[[Page Unknown]]
[Federal Register: March 24, 1994]
_______________________________________________________________________
Part IV
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 61
National Emission Standards for Hazardous Air Pollutants and Radon
Emissions From Phosphogypsum Stacks; Final Rule
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 61
[FRL-4849-9]
National Emission Standards for Hazardous Air Pollutants;
National Emission Standard for Radon Emissions From Phosphogypsum
Stacks
AGENCY: Environmental Protection Agency.
ACTION: Decision concerning petition for reconsideration.
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SUMMARY: On June 3, 1992, EPA issued a final rule revising 40 CFR part
61, subpart R, the National Emission Standard for Radon Emissions From
Phosphogypsum Stacks (57 FR 23305, June 3, 1992). The Fertilizer
Institute (TFI) filed a petition seeking reconsideration of the 1992
rule pursuant to Clean Air Act section 307(d)(7)(B). This notice sets
forth the Agency's decision concerning the TFI reconsideration
petition.
EPA has decided to partially grant and to partially deny the TFI
petition for reconsideration. EPA will reconsider 40 CFR 61.205, the
provision of the final rule which governs distribution and use of
phosphogypsum for research and development, and the formula in 40 CFR
61.207(d). EPA will publish a separate Federal Register notice
convening a proceeding to reconsider these provisions shortly. EPA is
denying the remainder of the TFI petition. In this notice, EPA
summarizes the principal remaining objections by TFI. EPA also explains
why these objections are not of central relevance to the outcome of the
rule and therefore do not constitute a basis for reconsideration.
DATES: Under Clean Air Act sections 307(b)(1) and 307(d)(7)(B), TFI may
seek judicial review of the decision by EPA to partially deny its
August 3, 1992 petition only by filing a petition for judicial review
in the United States Court of Appeals for the District of Columbia
Circuit within 60 days of the date of publication of this notice in the
Federal Register.
FOR FURTHER INFORMATION CONTACT: Jacolyn Dziuban, Air Standards and
Economics Branch, Criteria and Standards Division (6602J), Office of
Radiation and Indoor Air, Environmental Protection Agency, Washington,
DC 20460, (202) 233-9474.
SUPPLEMENTARY INFORMATION:
I. Background
Phosphogypsum is a waste resulting from wet acid phosphorus
production. Phosphogypsum stacks are piles of waste or mines utilized
to store and dispose of phosphogypsum. EPA issued a National Emission
Standard for Hazardous Air Pollutants (NESHAP) applicable to radon
emissions from such stacks in 1989, 40 CFR part 61, subpart R (54 FR
51654, December 15, 1989). As part of that standard, EPA adopted a work
practice requirement that all phosphogypsum be disposed in stacks,
thereby permitting control and measurement of gaseous radon-222 which
is emitted when radium present in the phosphogypsum decays.
Subsequent to issuance of Subpart R, EPA received petitions for
reconsideration from The Fertilizer Institute (TFI), Consolidated
Minerals, Inc., and U.S. Gypsum Company. These petitioners objected to
the requirement that all phosphogypsum be disposed and managed in
stacks, because it operated to preclude various alternative uses of
phosphogypsum, including use of phosphogypsum in agriculture,
construction, and research and development. Because EPA had not fully
considered the implications of its work practice standard for
alternative uses, EPA agreed to convene a reconsideration proceeding in
which the risks associated with alternative uses and the procedures
under which alternative uses might be permitted could be evaluated (54
FR 9612, March 7, 1989).
Rather than setting forth one specific proposal for revision of
subpart R, EPA requested comment on a variety of substantive issues,
including specific types of proposed alternative uses of phosphogypsum
and the health risks associated with these alternative uses. EPA also
requested comment on four general options for regulation of alternative
uses: (1) No change in the work practice requirement, (2) changing the
definition of phosphogypsum to exclude from the work practice
requirement material with radium-226 concentrations up to 10
picocuries/gram (pCi/g), (3) permitting use of phosphogypsum in
research and development on processes to remove radium from the
phosphogypsum, and (4) permitting alternative use of phosphogypsum only
after specific permission from EPA.
After analyzing the risks associated with the various alternative
uses of phosphogypsum which were proposed and evaluating the comments
which were received, EPA issued a final rule revising subpart R (57 FR
23305, June 3, 1992). The approach which EPA ultimately adopted was a
hybrid of the options it had previously identified. For phosphogypsum
use in agriculture, EPA decided that it would be impractical to require
case-by-case approval. Based on its analysis of potential risks
associated with long-term use of phosphogypsum in agriculture, EPA set
a maximum upper limit of 10 pCi/g for radium-226 in phosphogypsum
distributed for use in agriculture. Rather than excluding material at
or below 10 pCi/g from the standard, EPA established sampling,
measurement, and certification procedures permitting such material to
be removed from stacks and sold for agricultural use. Based on analysis
of potential risks associated with the research and development use,
EPA decided to permit use of up to 700 pounds of phosphogypsum for a
particular research and development activity. EPA also decided to adopt
procedures permitting approval of other uses of phosphogypsum on a
case-by-case basis.
After EPA issued its final rule concluding the reconsideration
proceeding and revising subpart R, The Fertilizer Institute (TFI)
sought judicial review of the 1992 revisions of subpart R in The
Fertilizer Institute v. Environmental Protection Agency, No. 92-1320
(D.C. Cir.). TFI also filed a petition dated August 3, 1992 seeking
further reconsideration of the revisions of the rule pursuant to Clean
Air Act section 307(d)(7)(B). TFI, EPA, and ManaSota-88, another
petitioner who sought review of the 1992 rule in ManaSota-88 v.
Browner, No. 92-1330 (D.C. Cir.), later reached an agreement to jointly
move the D.C. Circuit Court of Appeals to stay judicial review of the
1992 rule, and the Court granted the motion. As part of that agreement,
EPA agreed to make a final decision whether to grant or to deny the TFI
petition for reconsideration by January 31, 1994. This notice sets
forth the Agency's decision concerning the TFI reconsideration
petition.
II. Standard for Reconsideration
Under Clean Air Act section 307(d)(7)(B), the EPA Administrator is
required to convene a reconsideration proceeding if: (1) The person
raising an objection to a rule can demonstrate to the Administrator
that it was impracticable to raise such objection within the time
permitted for public comment or the grounds for the objection arose
after the period for public comment, and (2) if the Administrator
determines that the objection is of central relevance to the outcome of
the rule. Therefore, reconsideration is not required if the objections
by a petitioner were raised or could reasonably have been raised during
the pendency of the rulemaking. Moreover, even in the circumstance
where a particular objection could not have been raised earlier,
reconsideration is not required if EPA determines that such objections
would not have altered the outcome of the rule had they been raised
earlier.
TFI argues in its petition that EPA should reconsider the entire
1992 rule revising subpart R because the 1989 notice convening the
reconsideration proceeding did not specify, or provide an opportunity
for comment on, the details of the technical methodology which EPA
subsequently utilized in analyzing the risks associated with
alternative uses of phosphogypsum. However, EPA does not believe that
it was obligated to select and specify each of the technical models to
be utilized in its analysis and to describe all of the analytic
assumptions to be utilized before convening the reconsideration
proceeding. TFI also argues in its petition that a number of the
elements of the rule as it was promulgated were not specifically
proposed for notice and comment. In general, EPA believes that the
provisions of the rule adopted in 1992 were a logical outgrowth of the
options described in the 1989 reconsideration notice and the comments
received concerning those options.
EPA acknowledges that TFI did not have sufficient information to
state many of the detailed technical objections set forth in its
petition for reconsideration within the period provided for public
comment. However, under the criteria set forth in CAA section
307(d)(7)(B), it is still necessary for EPA to assess the substantive
significance of each of these objections to determine whether it is of
central relevance to the outcome of the rule and therefore an
appropriate basis for reconsideration.
Applying the criteria for reconsideration set forth in section
307(d)(7)(B) to the August 3, 1992 TFI petition, EPA has concluded that
certain objections raised by TFI do warrant convening a reconsideration
proceeding concerning particular provisions included in the 1992
revisions to Subpart R, but that the remaining objections by TFI do not
warrant reconsideration of the remaining provisions of the 1992 rule.
III. Decision to Partially Grant Petition
In its petition, TFI objects that the EPA analysis of the potential
risks associated with the use of phosphogypsum in research and
development assumes an emanation rate for radon from phosphogypsum in
the laboratory 40 times greater than the rate for phosphogypsum in
stacks, and that EPA has therefore greatly overestimated the risk
presented by the research and development use. TFI also argues that the
analysis by EPA assumed that normal good laboratory practices, such as
segregated storage of hazardous materials, limiting removal of
materials to an as needed basis, appropriate ventilation, and
appropriate disposal of used material, would be disregarded.
The analysis by EPA of the potential risks associated with the
research and development use assumed that all of the free radon
generated by phosphogypsum containing 26pCi/g radium-226 would be
released to a small laboratory room with a total volume of 64 cubic
meters and an air volume of 50 cubic meters. The EPA analysis thus
assumed that none of the radon would be retained in the physical matrix
of the phosphogypsum long enough to permit further decay the radon and
adsorption of the decay products, which would prevent release of
gaseous radon to the laboratory environment. While there are certainly
some experiments or circumstances where all of the radon generated by
decay of radium in the phosphogypsum could be released in the
laboratory, EPA has concluded that this would be unusual and that such
high emanation rates would be infrequent.
In addition, EPA discovered during its review of the analysis of
potential risks associated with the research and development use that
EPA assumed in its estimation of radon emissions to the laboratory
environment that five 700 pound drums would be stored or utilized in
the same area of the laboratory, rather than the single 700 pound drum
permitted by the rule. As a consequence, the portion of the risk to
laboratory personnel attributable to radon emissions was overestimated
by a factor of five. In view of these conclusions, EPA has determined
that the objections by TFI are of central relevance to the provision
limiting use of phosphogypsum in research and development to no more
than 700 pounds, and that EPA should request further comment on the
assumptions to be utilized in analyzing the risks associated with the
research and development use.
In its petition, TFI also argues that it is not clear from the text
of the 1992 rule whether more than one research and development
activity utilizing 700 pounds of phosphogypsum would be permitted at a
single facility, as well as whether or not a single research activity
would be limited to a total of 700 pounds or only to 700 pounds at any
given time. TFI states that it assumes that multiple research and
development activities each utilizing 700 pounds of phosphogypsum would
be permitted at a single facility, and that the 700 pound limit applies
only to the amount of phosphogypsum on hand at any given time, but
requests that EPA clarify the rule. EPA believes that TFI has correctly
construed the rule and questions the need for further clarification of
the existing rule. However, the fact that a given laboratory worker
might be exposed to radiation as a result of more than one research and
development activity utilizing phosphogypsum was not considered in the
EPA risk analysis. Accordingly, EPA has decided that it will also
request comment on whether there should be any limit on multiple
research and development activities at a single facility or by a
particular investigator, and how the possibility of greater exposures
attributable to multiple research and development activities should be
accounted for in the EPA analysis.
In its petition, TFI objects that it is not clear what purpose is
served by requiring owners or operators to conduct sampling or
measurement of radium-226 in phosphogypsum distributed for use in
research and development, because there is no quantitative limit on the
amount of radium-226 which phosphogypsum distributed for this use may
contain. Because there is no limit on the amount of radium permitted in
phosphogypsum distributed for research and development use, EPA assumed
in its analysis of potential risks associated with such use that the
phosphogypsum would contain high levels of radium. EPA believes that in
most instances analysis of the radium-226 content in phosphogypsum
distributed for use in research and development will be necessary as
part of the research activity. However, EPA has concluded that
requiring certification documents accompanying phosphogypsum
distributed for use in research and development to include quantitative
analyses of radium content is not necessary to monitor compliance.
Accordingly, EPA has decided that this objection by TFI is also of
central relevance to the outcome of this provision.
In view of the multiple objections by TFI which are of central
relevance to the outcome of 40 CFR 61.205, the provision of the revised
Subpart R governing distribution of phosphogypsum for use in research
and development, EPA has decided to partially grant the TFI petition by
convening a proceeding to reconsider 40 CFR 61.205. To implement this
decision, EPA is preparing and will publish shortly a notice of
reconsideration specifying the specific subjects on which further
comment will be requested and the range of options to be considered.
In its petition, TFI objects that the formula set forth in 40 CFR
61.207(d), which is used to establish the number of samples necessary
to determine a representative average radium-226 concentration, is
ambiguous, because it does not specify the amount of allowable error.
EPA agrees with this objection. The failure to include an allowable
error component in the formula was an inadvertent omission. EPA
believes that it would not be necessary to convene a reconsideration
proceeding for the sole purpose of correcting this inadvertent
omission, but has decided to include 40 CFR 61.207(d) among the
provisions to be reconsidered. To assist affected facilities in
complying with the existing rule while the reconsideration proceeding
is pending, EPA will provide specific guidance in the notice of
reconsideration concerning selection of an appropriate error component.
IV. Decision to Partially Deny Petition
EPA has carefully reviewed all of the remaining objections set
forth in the TFI petition for reconsideration. Based on that review,
EPA has concluded that none of the remaining technical objections by
TFI to the EPA analysis of the potential risks of phosphogypsum use are
of central relevance to the outcome of the 1992 rule. In addition, EPA
has determined that some of the remaining policy objections by TFI
could have been raised during the public comment period, and that none
of the remaining policy objections is of central relevance to the
outcome of the rule.
Based on its review of the remaining objections in the TFI petition
for reconsideration, EPA is denying the TFI petition with respect to
all provisions in the rule not specifically included in the decision to
grant reconsideration set forth above. The Agency's response to each of
the remaining TFI objections is summarized below.
A. Technical Objections
Objection: The radon emanation coefficient of 0.3 for phosphogypsum
is too high. Field observations (HP91) and the PATHRAE model (EPA87)
suggest the radon emanation coefficient for phosphogypsum in soil
should be 0.2. The coefficient used is 50 percent larger than suggested
by empirical data, but no explanation is given for why the higher value
was selected.
Response: The selection of 0.3 for the radon emanation coefficient
(E) is based on 30 measurements using phosphogypsum from four sites in
central Florida and Texas (RO88). As this reference is not publicly
available, it was not cited in the Background Information Document
(BID). The measurements were made at typical in-situ moistures for
phosphogypsum stacks. The arithmetic average of these data is about
0.35. Thus, the value of 0.3 used in the BID is reasonable and
applicable.
The data and other information (NI82) show the dependence of E on
moisture. At lower moisture levels E increases significantly with
moisture. This is also demonstrated in the work of van Dijk and deJong
(HP91) referenced by TFI. As their Figure 4 shows, E for phosphogypsum
can increase by more than 50 percent as equilibrium moisture increases.
The E values of 0.18 and 0.19, reported in their Table 2 and referenced
by TFI, are for nearly their driest conditions. As they were interested
in the effects of using phosphogypsum in building materials, these
lower values were appropriate. However, the exalation rates that they
measured at higher moistures give E values of about 0.28. This is
consistent with the value of 0.30 used in the risk assessments.
Moisture saturations in soils under residences are expected to be near
the values in the Rogers measurements and closer to the higher moisture
measurements by van Dijk and deJong.
The higher emanation coefficients are further confirmed in field
measurements of the specific radon flux from the surface of
phosphogypsum stacks. In 1985, Dr. C.E. Roessler (University of
Florida) determined that the specific radon flux from phosphogypsum
stacks in central Florida was 1 pCi/m2-s per pCi/g of Ra-226 in
the phosphogypsum. This value requires an E value of at least 0.29.
TFI also commented that an E of 0.2 was used in the PATHRAE model
(EPA87). This value was used in an example problem in the reference.
However, the example problem was for soil, not phosphogypsum, and
should not be construed as a recommendation for all cases.
Objection: The radon diffusion for concrete is given as 16 m2/
y. Published measurements of radon diffusion in concrete (HP80a, HP83)
provide values that are factors of 8 to 15 lower. Use of the lower
radon diffusion coefficients would reduce the indoor radon risks by a
factor of about two.
Response: The value of 16 m2/y (5.1 x 10-3 cm2/s)
for the radon diffusion coefficient of concrete (Dc) is the upper
end of the range of Dc's measured for residential concretes by
Nielson and Rogers (NI91). The upper end of the range was used because
PATHRAE only considers radon diffusion as the entry mechanism for soil
radon. While diffusion may dominate radon entry (TA90, RO90), advective
transport is also a factor and may dominate under some circumstances
(RO90, LO90). The value that was used for Dc in the risk
assessments partially accounts for the radon entry by advection.
TFI refers to Dc measurements made by Zapalac (HP83) and
Stranden and Berteig (HP80a). Zapalac reports Dc values of 3.3 x
10-4 cm2/s and 6.0 x 10-4 cm2/s for concretes
with densities of 2.3 and 2.4 g/cm3. The measurements by Rogers
and Nielson (RO90) also give the dependence of Dc on the concrete
density. The residential concretes that they tested had densities
generally of 2.1 g/cm3 or less. For the densities used by Zapalac,
the Rogers and Nielson correlation predicts Dc values of 1.2 x
10-4 and 4.0 x 10-4 cm2/s. Thus, the data used in the
risk assessments are consistent with Zapalac's data.
Stranden and Berteig did not give the densities for their concrete,
so a direct comparison is not possible. However, it is worth noting
that since the Stranden and Berteig measurements relied only on the
radon generated within the concrete, they are not a very sensitive
measure of Dc. Since a significant fraction of residential
concretes have densities less than 2.2 g/cm3, the value of 5.1 x
10-3 cm2/s for Dc is reasonable for the risk
assessments.
Objection: The radon decay product equilibrium fraction of 0.5 is
the upper bound of the range of 0.3 to 0.5 found in the Florida
Statewide Radiation Study. The average indoor radon equilibrium
fraction from houses where the radon concentrations ranged from 0.4 to
>8 pCi/l was 0.42. The National Council on Radiation Protection and
Measurements (NCRP) in its Report 94 and the United Nations Scientific
Committee on the Effects of Atomic Radiation (UNSCEAR) recommend 0.4 as
an indoor equilibrium fraction. The selected value of 0.5 is also
inconsistent with the assumption of 2 air changes per hour. Krisiuk
(HP80b) gives a value of 0.36 for a ventilation rate of 2 air changes
per hour. If other removal mechanisms are considered (e.g., plateout
and deposition), the equilibrium would be even lower. Use of 0.5 for
the equilibrium fraction results in overestimating the risks from
indoor radon exposure by a factor of at least 1.4.
Response: The EPA's radon risk factor incorporates a 0.5
equilibrium fraction. The value of 2 air changes per hour was not
chosen to be consistent with the radon decay product equilibrium
fraction. If they were made consistent, then 1 air change per hour
(HP80b) would have been used. The value of 1 air change per hour is
about the average for residences in the United States (NA88), and
results in an average equilibrium fraction of about 0.5. Thus, the use
of 2 air changes per hour in the risk assessments is non-conservative.
Objection: Based on estimates of the NCRP in Report No. 45, the
PATHRAE model overestimates the effective gamma dose rate by a factor
of 2.5.
Response: For Scenarios 1 and 2, the BID gives an annual external
gamma dose equivalent of 3.5 mrem/y from a soil Ra-226 concentration of
0.69 pCi/g. This is equal to a dose rate of 2.5 urad/h per Pci/g of Ra-
226. TFI references the 1.6 urad/hr per pCi/g value recommended by the
NCRP (NCRP75 and NCRP87). Thus, the NCRP's value is lower than the
PATHRAE results by 36 percent, not the factor of 2.5 claimed by TFI.
The external gamma dose rate at a given distance above soil
containing Ra-226 depends on the source geometry and the self-
absorption of the radiation in the soil. For the conditions being
assessed, an infinite plane best describes source geometry and the
PATHRAE model used an infinite plane dose factor for Ra-226 and its
decay products of 1.67 x 10-4 mrem/y per pCi/m2. As this
value is nearly the same as the value of 1.69 x 10-4 mrem/y per
pCi/m2 used by the DOE (DOE88), it does not appear to be too high.
The effect of self-absorption is quite variable and depends on the soil
density and the low gamma energy cutoff value. The NCRP's theoretical
value is based on work by Beck (BE75), which assumes a soil density of
1.6 g/cm3 and used 50 KeV as the low energy cutoff values. These
differences, particularly the difference in the low energy cutoff
values, account for the differences between the BID and the results
that would be obtained using the NCRP's value of 1.6 urad/hr per pCi/g.
It should also be noted that both values (1.6 urad/hr per pCi/g and 2.5
urad/hr per pCi/g) are within the variability of field measurements.
Objection: The use of a 70 year exposure period for residential
scenarios is inconsistent with the Superfund policy of using 90th
percentile estimates. The 90th percentile value is 30 years.
Response: The BID generally reports lifetime risk per year of
exposure. However, in Scenario 7, the risks for a lifetime of exposure
are presented by multiplying the risk per year of exposure by 70 years.
This is consistent with the EPA's policy under the Clean Air Act which
was explained in the preamble to the 1989 National Emission Standards
for Radon Emissions from Phosphogypsum Stacks (54 FR 51661) and which
has been used in these rulemaking proceedings.
However, as explained in the preamble, the difference that would be
caused by assuming a shorter period of exposure is not very
significant. For an assumed constant rate of exposure, people receive
over 60% of their total lifetime risk during their first nineteen
years. To change the period of exposure from 70 years to the first 19
years of life would change the final results by less than a factor of
two.
Objection: Radioactive decay during the 70-year residential
exposure period is neglected.
Response: Neglecting radioactive decay during the 70-year
residential exposure period introduces a negligible conservatism to the
results. Accounting for radioactive decay would have reduced the
estimated risks by about 1.5 percent.
Objection: The BID fails to account for removal of soil during home
construction at former phosphogypsum use sites.
Response: Some home construction may involve the removal of the
contaminated soil. However, it is more likely that the homes would have
the contaminated soil under or adjacent to them. Since the analysis
focused on the potential risks to the most exposed members of the
population, assuming that the contamination remains under and adjacent
to any homes that are built is reasonable.
Objection: The derivation of the presumptively safe level of 10
pCi/g Ra-226 for phosphogypsum used in agriculture is based on the 95th
percentile application rate of 2,700 lb/acre for 100 years. Using the
90th percentile rate, per Superfund policy, would be more appropriate.
More importantly, the application rate of 2,700 lb/acre is for soil
reclamation rather than soil productivity. Soil reclamation would not
require applications at this rate over a 100-year period. By combining
the application rate for soil reclamation with the frequency rate for
soil productivity the EPA has greatly overestimated the total
phosphogypsum application that would occur over the 100-year period.
Response: Superfund guidance is not necessarily applicable under
this NESHAP. However, TFI has not correctly stated the Superfund
guidance. That guidance for calculating reasonable maximum exposure
calls for the choice of 95th percentile values where available, or 90th
percentile values where 95th percentile values are not available.
The 95th percentile application rate for phosphogypsum used in
agriculture was calculated from data reported by TFI, based on a
questionnaire they sent to users of phosphogypsum (Docket A-79-11, XV-
D-100A, appendix, Tab 38). The 95th percentile was based on considering
application rates for a variety of crops produced in California and for
peanut production in the South, based on the assumption that
agricultural usage of phosphogypsum is about equally split between the
California and the remainder of the U.S. Although the data from
California show much higher application rates than those for peanuts,
we do not believe that California's rates are necessarily associated
with reclamation. Phosphogypsum is used for land reclamation in
California; however, an expert on the use of phosphogypsum in
California estimates that the application rate for reclamation is about
10,000 pounds per acre, considerably higher that the rates reported in
the TFI questionnaire. He also estimates that the application rate for
production is approximately equal to the rates reported in the TFI
questionnaire (Docket A-79-11, XVII-B-41).
Objection: The assessment of agricultural use does not consider the
differing application rates in different geographic areas of the
country.
Response: The risk analysis in the BID gives risks for various
application rates. Use of the 95th percentile application rate to
select a single value for the maximum permissible radium-226 content in
phosphogypsum distributed for agricultural use greatly simplifies
compliance and enforcement procedures.
Objection: The method prescribed for determining Ra-226
concentrations is for airborne effluents, not solids.
Response: The rule references Method 114 in appendix B of part 61.
Method 114 provides requirements for: (1) Stack sampling of effluents;
(2) radiochemical methods for determining the quantity of radionuclides
in a sample; and (3) quality assurance methods. Clearly, the portions
of Method 114 that relate to the collection of the effluent sample are
not applicable to determining the Ra-226 content of phosphogypsum
removed from a stack. However, the portions of Method 114 that relate
to radiochemical methods of determining the quantity of Ra-226 present
in the phosphogypsum (i.e., ``the principles of measurement'') and the
specified quality assurance methods are valid regardless of how the
sample was obtained.
B. Policy Objections
Objection: The EPA analysis of potential risks and the EPA decision
criteria with respect to the use of phosphogypsum in road construction
are absurd, because even naturally occurring materials would not meet
the EPA standard for a presumptively safe level of exposure to
radioactivity.
Response: It is well known that naturally occurring radium-226
levels in soil can release amounts of radon which are potentially
hazardous to occupants of structures built on such soil. Phosphogypsum
can contain radium-226 levels far in excess of the amount of activity
naturally present in soil. It is not absurd for EPA to take actions to
control the additional risks associated with the higher activity levels
in phosphogypsum simply because naturally occurring construction
materials may also present a risk in some circumstances.
Objection: The requirement that a person generating phosphogypsum
must first place it in a stack, and then measure and certify the radium
activity in the stack, before removing phosphogypsum from the stack and
distributing it for alternative use is cumbersome and unnecessary.
Instead, if phosphogypsum is designated for reuse, segregated, and
routed to a distribution holding point, the radium-226 content of the
phosphogypsum can be measured at either the segregation or the
distribution point.
Response: The provisions permitting distribution of phosphogypsum
for alternative uses are specific exceptions to the work practice
requirements which require persons generating phosphogypsum to dispose
of the material in a stack and to manage the stack in a specified
manner. For the provisions in the rule to operate properly, the
generator of phosphogypsum must determine that a given quantity of
phosphogypsum conforms to all of the requirements for distribution for
alternative uses before such distribution occurs. To the extent that
TFI is suggesting that persons other than those who generated the
phosphogypsum in the first instance should be permitted to measure the
radium-226 activity levels after distribution of the phosphogypsum has
already occurred, this cannot be reconciled with the Agency's objective
to assure safe disposal in managed and monitored stacks of all
phosphogypsum which does not meet the threshold requirements for
distribution for alternative uses.
EPA notes that 40 CFR 61.201(c) defines any pile of phosphogypsum
waste as a phosphogypsum stack. If the person who generates the
phosphogypsum in the first instance wishes to segregate phosphogypsum
designated for alternative use in a separate stack and measure the
activity levels in that stack separately, the rule permits this
approach. However, any materials in any additional stack which are not
lawfully distributed for an alternative use must be managed by the
owner or operator in the manner specified by the rule.
Objection: The limitation to 700 pounds of phosphogypsum for each
specific research and development activity necessarily means that
research and development in the field will be impossible.
Response: EPA notes that it has decided to reconsider the 700 pound
limitation. However, 40 CFR 61.205 was designed to permit research and
development activities involving phosphogypsum to proceed in the
laboratory, not to authorize large scale field research. Proposals to
conduct field studies utilizing phosphogypsum should instead be
submitted for prior EPA approval pursuant to 40 CFR 61.206.
Objection: The procedures for certification in 40 CFR 61.208 are
overly burdensome and unnecessary. They require a multi-party paperwork
trail for materials that are presumptively safe. EPA should just
require the person who generates phosphogypsum to certify at the end of
the year that all of its shipments met applicable legal requirements.
Response: EPA believes that the procedures requiring distributors,
retailers, or resellers to prepare certification documents and to
retain copies of certification documents provided by the person from
whom the phosphogypsum was obtained are necessary to adequately monitor
compliance with the requirements in the rule. Without such
documentation, it would be much more difficult or even impossible to
investigate and take appropriate enforcement action if non-conforming
phosphogypsum is found to have been distributed or sold for an
alternative use. EPA notes that farmers or agricultural end-users who
purchase phosphogypsum for an agricultural use are not required to
prepare or maintain records, but that distributors who sell
phosphogypsum for an agricultural use must do so.
Objection: Risks associated with phosphogypsum use should be
controlled by state and local governments through restrictions on
building construction rather than by EPA.
Response: EPA hopes that state and local governments will adopt
appropriate measures to control hazards associated with radon emissions
at building sites. However, EPA does not believe that it is appropriate
for EPA to sanction specific activities which unduly increase the
radium content of the land and the risks associated with building
construction, based on an assumption that state or local building codes
will mitigate the resultant problem.
V. Judicial Review
The decision by EPA to partially deny the August 3, 1992 TFI
petition for reconsideration is final agency action based on a
determination of nationwide scope or effect. TFI may seek review of the
decision by EPA to partially deny its petition in the United States
Court of Appeals for the District of Columbia Circuit within 60 days
from the date this notice is published in the Federal Register. EPA
notes that TFI has previously agreed that, if TFI seeks judicial review
of the decision by EPA to partially deny its petition for
reconsideration, TFI will move to consolidate such review with the
review of the 1992 rule which is currently pending in The Fertilizer
Institute v. Environmental Protection Agency, No. 92-1320 (DC Cir.) and
ManaSota-88 v. Browner, No. 92-1330 (DC Cir.).
The decision by EPA to partially grant the TFI petition does not
constitute final agency action and is therefore not presently subject
to judicial review. After EPA takes final action in the resulting
reconsideration proceeding, any person who participated in that
proceeding may seek judicial review of such action.
VI. References
BE75 Beck, H.L., ``The Physics of Environmental Gamma Radiation
Fields,'' Proceedings, Natural Radiation in the Environment II,
1975.
DOE88 U.S. Department of Energy, External Dose-Rate Conversion
Factors for Calculation of Dose to the Public, DOE/EH-0070, 1988.
EPA87 U.S. Environmental Protection Agency, Low-Level and NARM
Radioactive Wastes Model--PATHRAE-EPA Methodology and Users Manual,
EPA 520/1-87-028, 1987.
HP80a Stranden, E. and Berteig, L., ``Radon in Dwellings and
Influencing Factors,'' Health Physics 30:275, 1980.
HP80b Krisiuk, E.M., ``Airborne Radioactivity in Buildings,'' Health
Physics 38:199, 1980.
HP83 Zapalac, G.H., ``A Time-Dependent Method for Characterizing the
Diffusion of 222Rn in Concrete,'' Health Physics 45:377, 1983.
HP91 van Dijk, W. and deJong, P., ``Determining the 222Rn
Exhalation Rate of Building Materials Using Liquid Scintillation
Counting,'' Health Physics 61:501, 1991.
LO90 Loureiro, C.O., et al., ``Three-Dimensional Simulation of Radon
Transport into Houses with Basements Under Constant Negative
Pressure,'' Environmental Science and Technology 24:1338, 1990.
NA88 Nazaroff, W.W. and Nero, A.V., Radon and Its Decay Products in
Indoor Air, pp. 131-157, John Wiley & Sons, New York, 1988.
NCRP75 National Council on Radiation Protection and Measurements,
Natural Background Radiation in the United States, NCRP Report No.
45, 1975.
NCRP87 National Council on Radiation Protection and Measurements,
Exposure of the Population in the United States and Canada from
Natural Background Radiation, NCRP Report No. 94, 1987.
NI82 Nielson, K.K., ``Radon Emanation Characteristics of Uranium
Mill Tailings,'' Proceedings of the Fifth Symposium on Mill Tailings
Management, pp. 355-567, Colorado State University Press, 1982.
NI91 Nielson, K.K., and Rogers, V.C., ``Radon Entry into Dwellings
Through Concrete Floors,'' Proceedings of the 1991 International
Symposium on Radon and Radon reduction Technology, Philadelphia, PA,
EPA-600/9-91-37c, 1991.
RO88 Rogers, V.C., Characterization of the Former Borden Property in
Texas City, Texas, Rogers and Associates Engineering Corp., RAE
8602/1-2, 1987.
RO90 Rogers, V.C. and Nielson, K.K., ``Benchmark and Application of
the RAETRAD Model,'' Proceedings of the 1990 International Symposium
on Radon and Radon Reduction Technology, Atlanta, GA, EPA/600/9-90/
005c, 1990.
TA90 Tanner, A.B., ``The role of Diffusion in Radon Entry in
Houses,'' Proceedings of the 1990 International Symposium on Radon
and Radon Reduction Technology, Atlanta, GA, EPA/600/9-90/005c,
1990.
Dated: March 7, 1994.
Carol M. Browner,
Administrator.
[FR Doc. 94-5993 Filed 3-23-94; 8:45 am]
BILLING CODE 6560-50-P