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Ammonia; Ammonium Sulfate (Solution); Ammonium Nitrate (Solution); Water Dissociable Ammonium Salts; Toxic Chemical Release Reporting; Community Right-to-Know

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

 [Federal Register: April 3, 1995]

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 372

[OPPTS-400032A; FRL-4944-8]
RIN 2070-AC00
 
Ammonia; Ammonium Sulfate (Solution); Ammonium Nitrate 
(Solution); Water Dissociable Ammonium Salts; Toxic Chemical Release 
Reporting; Community Right-to-Know


AGENCY: Environmental Protection Agency (EPA).


ACTION: Amended proposed rule.




SUMMARY: EPA is amending its March 30, 1990 proposal to grant a 
petition to delete ammonium sulfate (solution) from the list of toxic 
chemicals subject to reporting under section 313 of the Emergency 
Planning and Community Right-to-Know Act of 1986 (EPCRA). The March 30, 
1990 proposal was based on EPA's belief that releases of ammonium 
sulfate (solution) can be more effectively covered by the EPCRA section 
313 ammonia listing. EPA is amending the proposed rule in order to 
allow the public to comment on data not available or included at the 
time of the original proposal. EPA is also expanding the proposal to 
include the deletion of ammonium nitrate (solution) as a separately 
listed toxic chemical on the EPCRA section 313 list because EPA 
believes that releases of ammonium nitrate (solution) are more 
effectively covered by the EPCRA section 313 listings for ammonia and 
the recently added water dissociable nitrate compounds category. In 
addition, EPA is proposing to modify the ammonia listing to make it 
clear that aqueous ammonia from all water dissociable ammonium salts is 
reportable under the EPCRA section 313 listing for ammonia. In the 
March 30, 1990 proposal, EPA discussed two options for the reporting of 
aqueous ammonia, as total ammonia or as some proportion of total 
ammonia. Today, EPA is proposing that 10 percent of total aqueous 
ammonia be reported under the ammonia listing.


DATES: Written comments must be received by May 3, 1995.


FOR FURTHER INFORMATION CONTACT: Maria J. Doa, Petitions Coordinator, 
202-260-9592, for specific information on this amended proposed rule, 
or for more information on EPCRA section 313, the Emergency Planning 
and Community Right-to-Know Hotline, Environmental Protection Agency, 
Mail Code 5101, 401 M St., SW., Washington, DC 20460, Toll free: 1-800-
535-0202, in Virginia and Alaska: 703-412-9877 or Toll free TDD: 1-800-
553-7672.


SUPPLEMENTARY INFORMATION:


I. Introduction


A. Statutory Authority


    This amended proposal is issued under section 313(d) and (e)(1) of 
the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA), 
42 U.S.C. 11023. EPCRA is also referred to as Title III of the 
Superfund Amendments and Reauthorization Act of 1986 (SARA) (Pub. L. 
99-499).


B. Background


    Section 313 of EPCRA requires certain facilities manufacturing, 
processing, or otherwise using listed toxic chemicals to report their 
environmental releases of such chemicals annually. Beginning with the 
1991 reporting year, such facilities must also report pollution 
prevention and recycling data for such chemicals, pursuant to section 
6607 of the Pollution Prevention Act (42 U.S.C. 13106). When enacted, 
section 313 established an initial list of toxic chemicals that was 
comprised of more than 300 chemicals and 20 chemical categories. 
Section 313(d) authorizes EPA to add chemicals to or delete chemicals 
from the list, and sets forth criteria for these actions. EPA has added 
chemicals to and deleted chemicals from the original statutory list. 
Under section 313(e)(1), any person may petition EPA to add chemicals 
to or delete chemicals from the list. Pursuant to EPCRA section 
313(e)(1), EPA must respond to petitions within 180 days either by 
initiating a rulemaking or by publishing an explanation of why the 
petition is denied.
    EPA issued a statement of petition policy and guidance in the 
Federal Register of February 4, 1987 (52 FR 3479), to provide guidance 
regarding the recommended content and format for petitions. On May 23, 
1991 (56 FR 23703), EPA issued a statement of policy and guidance 
regarding the recommended content of petitions to delete individual 
members of the section 313 metal compound categories. EPA has published 
a statement [[Page 16831]] clarifying its interpretation of the section 
313(d)(2) criteria for adding and deleting chemicals from the section 
313 list (59 FR 61439, November 30, 1994).
    Facilities that manufacture, process, or otherwise use ammonia, 
ammonium sulfate (solution), ammonium nitrate (solution), and other 
water dissociable ammonium salts may be affected by this amended 
proposed rule if they meet the following criteria: (1) The facility has 
the equivalent of 10 or more full-time employees; and (2) the facility 
is included in Standard Industrial Classification (SIC) Codes 20 
through 39; and (3) the facility manufactures (defined to include 
importing), processes, or otherwise uses the chemicals listed above in 
quantities equal to or greater than 25,000 pounds for manufacturing or 
processing and 10,000 pounds for otherwise using.


II. Description of Petition and Original Proposed Rule


A. Description of Petition


    On January 23, 1989, EPA received a petition from Allied-Signal 
Inc. to delete ammonium sulfate (solution) from the EPCRA section 313 
list of toxic chemicals. The petition was based on Allied-Signal Inc.'s 
contention that ammonium sulfate (solution) does not meet the EPCRA 
section 313 criteria for listing. Specifically, Allied-Signal Inc. 
claimed that: (1) Ammonium sulfate is not known to cause and cannot 
reasonably be anticipated to cause significant adverse acute human 
health effects at concentration levels that are reasonably likely to 
exist beyond facility site boundaries as a result of continuous, or 
frequently recurring releases, (2) ammonium sulfate does not show 
potential for causing in humans cancer or teratogenic effects, serious 
or irreversible reproductive dysfunction, neurological disorders, 
heritable genetic mutations, or other chronic health effects, and (3) 
ammonium sulfate does not show potential for adverse effects on the 
environment due to toxicity, persistency in the environment, and/or 
tendency to bioaccumulate in the environment.


B. Review of Proposed Rule


    On March 30, 1990, EPA issued a proposed rule in the Federal 
Register (55 FR 12144), proposing to delete ammonium sulfate (solution) 
from the EPCRA section 313 list of toxic chemicals. This proposal, 
hereafter referred to as ``the original proposal,'' was based on EPA's 
belief that the only concerns identified for ammonium sulfate 
(solution) were for the aqueous ammonia present in the solution and 
that this aqueous ammonia is more appropriately reported under the 
EPCRA section 313 listing for ammonia. Aqueous ammonia is 
coincidentally manufactured when ammonium salts that dissociate in 
water (such as ammonium sulfate) are dissolved in water. Therefore, 
releases of these ammonium salt solutions are environmentally 
equivalent to the release of aqueous ammonia generated by dissolving 
anhydrous ammonia in water.
    The original proposal and the combined docket for the original 
proposal and this proposed amendment contain complete discussions and 
documentation of EPA's technical review of ammonium sulfate (solution), 
aqueous ammonia, and the options EPA has considered for resolving the 
reporting requirements under the ammonia listing. The following two 
sections summarize EPA's technical evaluation and options as discussed 
in the original proposal.

    

  1.  Summary of technical review. The chemistry of ammonia in water 
(i.e., aqueous ammonia) has been extensively studied and is well 
understood. When anhydrous ammonia or water dissociable ammonium salts 
(such as ammonium sulfate) are dissolved in water an equilibrium is 
reached between two forms of ammonia, the un-ionized form (NH<INF>3) 
and the ionized form (NH<INF>4<SUP>+). The term ``total ammonia'' 
refers to the sum of both the un-ionized and ionized forms of ammonia 
and is synonymous with the term ``aqueous ammonia.'' The relative 
proportions of each form of ammonia are mainly dependent on the pH and 
temperature of the solution, with the amount of the un-ionized form 
increasing with both increased pH and increased temperature. These two 
forms rapidly interconvert and the relative proportions of each form 
change instantly with changes in the pH and temperature of the 
solution. The concentration of the un-ionized form of ammonia increases 
10-fold with each one unit increase in pH and approximately doubles 
with every 10  deg.C increase in temperature. There are differences in 
the concentrations of the un-ionized form of ammonia between equimolar 
solutions of aqueous ammonia generated by dissolving dissociable 
ammonium salts versus anhydrous ammonia. These differences are due to 
the buffering effects (mainly reflected as pH differences) of the 
counter ions from the ammonium salts and disappear when both solutions 
are released to the environment.
    EPA preliminarily concluded that there were no known significant 
human health effects associated with ammonium sulfate (solution). EPA 
also preliminarily concluded that the ecotoxicity concerns for ammonium 
sulfate (solution) were limited to the aqueous ammonia (i.e., total 
ammonia) present in these solutions and that the sulfate portion was 
not of concern. The toxicity of aqueous ammonia to aquatic organisms 
has been extensively studied and is well understood. The toxicity of 
aqueous ammonia solutions is primarily attributable to the un-ionized 
form of ammonia with the ionized form being relatively less toxic. 
Because both the toxicity of aqueous ammonia and the concentration of 
the un-ionized form of ammonia vary with the pH and temperature of the 
solution, aqueous ammonia toxicity cannot be represented solely by the 
concentration of unionized ammonia. Thus, the toxicity of an aqueous 
solution of ammonia cannot be represented by a single value but must be 
expressed as a function of pH and temperature. Since the un-ionized 
ammonia concentration changes with pH and temperature, it is necessary 
to calculate the total ammonia concentration in order to determine the 
toxicity of the solution as the pH and temperature conditions change.
    EPA's Office of Water has conducted a detailed study of the 
toxicity of aqueous ammonia which is provided in the criteria document, 
Ambient Water Quality Criteria for Ammonia - 1984. No new information 
has become available to the Agency that has significantly changed the 
conclusions reached in this document. Therefore, this document remains 
the Agency's aquatic toxicity hazard assessment for aqueous ammonia. 
The criteria developed for this document were derived from toxicity 
tests conducted with several ammonium compounds, including ammonium 
sulfate. The criteria are estimates of the highest concentrations that 
should not cause toxicity to aquatic organisms and are expressed as a 
function of pH and temperature. The criteria are presented in terms of 
both the concentrations of the un-ionized form of ammonia and the 
concentration of total ammonia.
    In the original proposal, EPA reported that the majority (95 
percent) of the ammonium sulfate consumed in the U.S. is used as a 
fertilizer and that, based on reports submitted to the Toxic Release 
Inventory (TRI), in 1987, 90.2 million pounds of ammonium sulfate 
(solution) were released to water and/or publicly-owned treatment works 
(POTWs). EPA conducted a limited exposure assessment based on data 
obtained from the TRI. The assessment focused on releases to surface 
waters [[Page 16832]] and POTWs since these releases will have a direct 
impact on aquatic ecosystems. EPA determined that 30 percent of the 
facilities reviewed were not being regulated through their State 
programs for discharges of ammonia.

  2.  Summary of options in the original proposal. EPA considered 
three options for responding to the petition:
    (i) Deny the petition.
    (ii) Grant the petition and propose to delete ammonium sulfate 
(solution) from the EPCRA section 313 list of toxic chemicals.
    (iii) Grant the petition and propose to delete ammonium sulfate 
(solution) while at the same time, use the rulemaking to revise release 
reporting of ammonia.
    EPA recognized that certain facilities might not be aware of the 
chemistry of aqueous solutions of ammonium salts. Therefore, under 
option (iii), EPA discussed three options concerning how to inform the 
regulated community of the technical determination that these solutions 
are equivalent to solutions of aqueous ammonia generated by dissolving 
anhydrous ammonia in water. The options considered were:
    (a) Create an ``ammonium salts'' category to make the technical 
determination more explicit.
    (b) Modify the ammonia listing to read as follows: ammonia 
(includes total ammonia resulting from solutions of water dissociable 
salts).
    (c) Revise EPA's guidance for ammonia reporting.
    EPA believed that creating an ammonium salts category would be 
confusing and could potentially cause problems concerning double 
reporting and reporting on salts that do not dissociate. EPA believed 
that modification of the ammonia listing was not necessary in order to 
capture releases of aqueous ammonium salt solutions and that it would 
reinforce the artificial distinction between releases of aqueous 
solutions of ammonia generated from anhydrous ammonia and those 
generated from water dissociable ammonium salts. EPA, therefore, issued 
technical guidance clarifying the reporting requirements under the 
ammonia listing.
    In the same issue of the Federal Register in which the proposal was 
published, a notice of availability was published (55 FR 12148) 
notifying the public and the regulated community of the availability of 
a guidance document on the reporting of ammonia releases. The guidance 
document explained that manufacturing, processing, or otherwise using 
aqueous solutions of ammonium salts that dissociate in water is 
equivalent to manufacturing, processing, or otherwise using aqueous 
ammonia solutions generated by dissolving anhydrous ammonia (an EPCRA 
section 313 listed toxic chemical) in water. Therefore, those 
facilities that manufacture, process, or otherwise use aqueous 
solutions of ammonium salts that dissociate in water should make 
threshold determinations under EPCRA section 313 to assess whether 
reporting for releases under the ammonia listing is required.
    In the original proposal, EPA also discussed two options for 
reporting releases of aqueous ammonia:
    (1) Report releases of total ammonia; or
    (2) Report a proportion of the releases of total ammonia.
    In discussing the two options, EPA stated that reporting total 
ammonia would allow communities to determine the proportion of unionized 
ammonia and ionized ammonia present in the receiving stream 
based on the pH and temperature characteristics of the stream. This 
information allows communities to easily determine the un-ionized 
ammonia and ionized ammonia loading resulting from facility releases of 
aqueous ammonia. EPA stated that although the ionized form of ammonia 
is less toxic to aquatic organisms than the un-ionized form of ammonia, 
it is present in a higher proportion under environmental conditions and 
may present the greater hazard. EPA also stated that reporting releases 
as a proportion of the amount of un-ionized ammonia released would 
result in data that cannot be used as well since it must be 
extrapolated to determine the amount of total ammonia released.
    EPA proposed the second option in recognition of the fact that the 
un-ionized form of ammonia is more toxic than the ionized form of 
ammonia and that under environmental conditions only a proportion of 
total ammonia contains un-ionized ammonia. EPA requested comment on 
whether a proportion, which would be the same for all facilities, of 
releases of total ammonia should be reported. EPA stated that this 
proportion would be a worst-case estimate of the proportion of the unionized 
form of ammonia present in processing waters reflecting an 
upper bound level of the amount of the un-ionized form of ammonia 
formed. EPA also requested comment on what proportion of total ammonia 
should be used as an estimate.


III. Rationale for Amending the Proposal


    The issue of what forms of ammonia should be reportable under the 
ammonia listing has been the source of ongoing discussions between EPA 
and affected parties since the publication of the original proposal. 
This has resulted in a significant amount of additional information 
becoming available to EPA, and is one of the reasons EPA is amending 
the proposed rule. This information has been placed in the docket for 
this rulemaking. Also, due to the recent addition of a nitrate 
compounds category to the EPCRA section 313 list of toxic chemicals (59 
FR 61439, November 30, 1994), EPA believes that it would be appropriate 
to expand the proposed rule to include the deletion of ammonium nitrate 
(solution) as a separately listed chemical under EPCRA section 313. 
Therefore, EPA decided to publish this amended proposal to allow for 
adequate public notice and comment.
    The following sections discuss this additional information as well 
as the expansion of the proposal to include the deletion of ammonium 
nitrate (solution).


A. Additional Information


      

    1.  Average pH and temperature of U.S. waters (Ref. 1). Data 
concerning the pH and temperature of lakes, rivers, and streams in the 
U.S. were not discussed or provided in the original proposal. This 
information is important since the pH and temperature of these 
receiving bodies will determine the proportion of aqueous ammonia that 
will exist in the more toxic un-ionized form. EPA has analyzed data 
tabulated from the Agency's STORET data base for all 50 states and 
found that at the 50th percentile for pH and temperature in surface 
waters, approximately 1 percent of aqueous ammonia would exist in the 
un-ionized form, at the 90th percentile it would be 10 percent, and at 
the 95th percentile it would be 15 percent. This information suggests 
an upper boundary for the amount of the un-ionized form of ammonia that 
will be generated from the releases of aqueous ammonia.

    2.  Toxicity data (Ref. 2). Additional data concerning the toxicity 
of aqueous ammonia to one aquatic organism has become available since 
the original proposal was issued. This new data indicate that the 
amphipod Hyalella azteca shows no dependency towards pH and temperature 
with regards to chronic toxicity from aqueous ammonia. This suggests 
that, for this organism, aqueous ammonia toxicity is not due primarily 
to the un-ionized form of ammonia and that, for this organism, the 
ionized form may be equally as toxic as the un-ionized form.

    3.  Environmental fate of aqueous ammonia (Ref. 3). Aqueous ammonia 
does not persist or bioaccumulate in the [[Page 16833]] environment as 
ammonia. In surface waters the important and competitive processes that 
remove aqueous ammonia are nitrification and volatilization. The rate 
of volatilization of ammonia from surface waters is highest at the 
sources of releases, while nitrification processes tend to be more 
significant in lakes, slow moving rivers, and estuaries. Nitrification, 
which is one process within the nitrogen cycle, involves two steps that 
yield metabolic energy for two specific microorganisms. In the first 
step, Nitrosomonas converts ammonia to nitrite and in the second step, 
Nitrobacter converts nitrite to nitrate. Because the nitrogen cycle is 
dynamic, industrial releases of aqueous ammonia should not result in 
dramatic buildups of ammonia in surface waters. Nitrification is 
responsive to high inputs of ammonia such as those from industrial 
releases. However, it should be noted that high nitrification may lead 
to low levels of dissolved oxygen and the eutrophication of a water 
body. This effect is typically limited to coastal waters and estuaries 
where nitrogen is the limiting nutrient. Aqueous ammonia may also be 
removed by adsorption to particles which then settle to the sediment 
where soil-type processes take over. The ionized form of ammonia is 
also assimilated by most plants.

    4.  Additional exposure information (Ref. 4). EPA has conducted an 
additional exposure analysis of releases of aqueous ammonia to surface 
waters. This exposure assessment analyzed the releases of ammonium 
sulfate (solution) and ammonium nitrate (solution) that were reported 
to the TRI for reporting year 1992. Releases of ammonia reported under 
the ammonia listing were not included since this data are a mixture of 
reports of total ammonia releases and un-ionized ammonia releases and 
EPA has no way to readily determine how a facility calculated its 
releases. Although this exposure assessment represents only a small 
portion of the aqueous ammonia released to surface waters, it was 
helpful in identifying facilities that might be releasing aqueous 
ammonia in concentrations that exceed water quality criteria. The 
results showed that not all facilities with significant releases of 
these ammonium salts are covered by permits that control releases of 
aqueous ammonia and for those that are covered by such permits 
violations of these permits occur.
    EPA has recently clarified how exposure information is used in 
listing and delisting decisions under EPCRA section 313 (59 FR 61432, 
November 30, 1994). EPA does not consider exposure information when 
evaluating whether highly ecotoxic chemicals meet the EPCRA section 
313(d)(2)(C) listing criteria. EPA believes that for highly ecotoxic 
chemicals it is sufficient to consider only hazard when determining 
whether a chemical meets the EPCRA section 313(d)(2)(C) listing 
criteria. EPA only considers exposure information when evaluating low 
or moderately ecotoxic chemicals. EPA considers the un-ionized form of 
ammonia to be highly toxic to aquatic organisms; therefore, EPA did not 
consider exposure information in evaluating whether aqueous ammonia 
from ammonium sulfate (solution) contributes to aquatic toxicity. The 
exposure information provided in this amended proposal and in the 
original proposal was not used as a basis for determining whether 
ammonium sulfate (solution) meets the EPCRA section 313(d)(2)(C) 
listing criteria, but was provided as additional information since many 
states issue permits that require monitoring or limitation of ammonia 
releases.

    5.  Science Advisory Board review (Ref. 5). In order to help resolve 
the scientific issues concerning the reporting of aqueous ammonia under 
the EPCRA section 313 ammonia listing, EPA asked the Agency's Science 
Advisory Board (SAB) to review the issues. The SAB assigned the review 
to the Toxics Reporting Subcommittee of the Ecological Processes and 
Effects Committee which met in Washington, DC on January 4, 1995, in a 
public meeting to discuss the issue. EPA submitted two questions for 
the subcommittee to respond to:
    (i) What is the most appropriate way to report releases of aqueous 
ammonia under EPCRA section 313: as un-ionized ammonia or as total 
ammonia?
    (ii) Does total ammonia meet the EPCRA section 313 listing 
criteria?
    The SAB responded with a letter to the Agency dated February 2, 

    6.  In this letter the SAB concluded that the acute toxicity of the 
un-ionized form of ammonia to aquatic life is approximately 100 times 
greater than the ionized form of ammonia and that the toxicity of the 
two forms is approximately additive. With regard to what form of 
ammonia should be reported under EPCRA section 313, the SAB stated 
that, for aquatic toxicity, reporting concentrations of the un-ionized 
form of ammonia at a standard pH and temperature would address this 
endpoint. The SAB also stated that for other effects such as nitrogen 
nutrient enrichment, the specific forms of ammonia are not very 
relevant since both have the same nutrient enrichment properties. The 
SAB went on to conclude, ``Thus, the question of whether to list or how 
to list ammonia or any of its forms is not a scientific issue but 
strictly a matter of policy for the Agency to decide.''
    With regard to whether total ammonia meets the EPCRA section 313 
criteria, the SAB stated that, based on their evaluation of the 
criteria, total ammonia meets the EPCRA section 313 criteria only if, 
as stated in the statute, the Administrator determines that it causes a 
significant adverse effect on the environment of sufficient seriousness 
to warrant reporting.


B. Proposed Deletion of Ammonium Nitrate (solution)


    Ammonium nitrate (solution) is a solution of aqueous ammonia and 
nitrate ions. On November 30, 1994 (59 FR 61432), EPA added a water 
dissociable nitrate compounds category to EPCRA section 313 . The 
addition of this category and reporting of aqueous ammonia from water 
dissociable ammonium salts under the ammonia listing obviate the need 
to have ammonium nitrate (solution) as a separately listed chemical 
under EPCRA section 313. EPA believes that the aqueous ammonia from 
ammonium nitrate (solution) is more appropriately reported under the 
EPCRA section 313 ammonia listing and that the nitrate portion of 
ammonium nitrate (solution) is more appropriately reported under the 
new water dissociable nitrate compounds category. Although EPA is 
proposing to delete ammonium nitrate (solution), this action would not 
result in any loss of information concerning releases of this material.


IV. Proposed Actions and Rationale


A. Proposed Actions


    EPA is proposing to take the following four actions:

        

      1.  Delete ammonium sulfate (solution) from the EPCRA section 313 
list of toxic chemicals.

      2.  Require that threshold and release determinations for aqueous 
ammonia be based on 10 percent of the total ammonia present in aqueous 
solutions of ammonia.

      3.  Modify the ammonia listing by adding the following qualifier: 
ammonia (includes anhydrous ammonia and aqueous ammonia from water 
dissociable ammonium salts and other sources; 10 percent of total 
aqueous ammonia is reportable under this listing).

      4.  Delete ammonium nitrate (solution) as a separately listed 
chemical on the EPCRA section 313 list of toxic 
chemicals. [[Page 16834]] 


B. Rationale for Proposed Actions


    The rationale for proposing each of these actions is discussed 
below.

          

        1.  Deletion of ammonium sulfate (solution). EPA agrees with the 
petitioner's claim that ammonium sulfate (solution) does not meet the 
human health listing criteria under EPCRA section 313(d)(2)(A) and (B). 
However, EPA does not agree with the petitioner's claim that ammonium 
sulfate (solution) does not show potential for adverse effects on the 
environment because when a facility dissolves ammonium sulfate in 
water, that facility, in effect, manufactures aqueous ammonia. The unionized 
form of ammonia present in aqueous ammonia is highly toxic to 
aquatic organisms and therefore meets the EPCRA section 313(d)(2)(C) 
criteria for listing. An aqueous solution of ammonium sulfate is 
environmentally equivalent to aqueous ammonia generated from anhydrous 
ammonia because when each of these solutions is released to receiving 
waters the amount of un-ionized ammonia present is dependent upon 
environmental conditions. In fact, ammonium sulfate is one of the many 
ammonium salts used by researchers as a source of aqueous ammonia for 
aquatic toxicity studies.
    EPA does not believe that the sulfate portion of ammonium sulfate 
(solution) meets the EPCRA section 313(d)(2)(A), (B), or (C) criteria. 
EPA has previously reviewed the toxicity of sodium sulfate (54 FR 7217 
and 54 FR 25850) and concluded that sulfate from sodium sulfate did not 
meet the EPCRA section 313(d)(2)(A), (B), or (C) criteria.
    EPA believes that the only component of ammonium sulfate (solution) 
that meets the EPCRA section 313 listing criteria is the aqueous 
ammonia present in this solution. EPA believes that this aqueous 
ammonia is more appropriately reported under the EPCRA section 313 
ammonia listing, therefore it is appropriate to delete ammonium sulfate 
(solution) from the EPCRA section 313 list of toxic chemicals. Ten 
percent of the ammonium portion of ammonium sulfate (solution) would 
remain reportable under the ammonia listing.

        2.  Reporting 10 percent of total ammonia. EPA has considered all 
data available to the Agency concerning the chemistry, toxicity, and 
environmental fate of aqueous ammonia and believes that: (1) Aqueous 
ammonia does not persist or bioaccumulate in the environment as 
ammonia, (2) the most toxic form of ammonia is the un-ionized form, (3) 
the un-ionized form of ammonia makes up a relatively small percentage 
of total ammonia under most environmental conditions, (4) reporting a 
percentage of total aqueous ammonia under the ammonia listing would 
adequately represent the toxicity of aqueous ammonia, and (5) reporting 
un-ionized ammonia without pH and temperature data would not provide 
sufficient information to quantify potential hazards from releases. EPA 
believes that reporting aqueous ammonia as 10 percent of total ammonia 
is appropriate since, based on the 90th percentile pH and temperature 
data for U.S. waters, releases of aqueous ammonia will consist of no 
more than approximately 10 percent of the un-ionized form of ammonia. 
Reporting aqueous ammonia as a percentage of total ammonia would also 
allow for easy determination of the amount of total ammonia released. 
The amount of total ammonia released, along with the site-specific pH 
and temperature data for the receiving body, are required in order to 
calculate the amount of un-ionized ammonia released to any one specific 
water body. Under this proposal, facilities would be required to 
include 10 percent of the total ammonia in aqueous solutions in all 
threshold and release determinations under the EPCRA section 313 
listing for ammonia. The proposal to report 10 percent of total ammonia 
is consistent with the original proposal in which EPA asked for comment 
on whether a proportion of total ammonia, that would be the same for 
all facilities, should be reported. This proposal is also consistent 
with the SAB conclusion that reporting un-ionized ammonia under 
standard conditions adequately addresses the aquatic toxicity endpoint. 
Also, users of TRI data who wish to assess the contribution of ammonia 
to nitrogen loading in nitrogen limited waters could extrapolate from 
the reported data.

        3.  Modification of the ammonia listing. In the original proposal, 
EPA discussed three ways to clarify that aqueous ammonia from water 
dissociable ammonium salts is reportable under the ammonia listing. One 
method considered was to add a modifier to the ammonia listing to read: 
ammonia (includes total ammonia resulting from solutions of water 
dissociable salts). EPA was concerned, however that such a modification 
would reinforce the artificial distinction between releases of aqueous 
solutions of ammonia generated from anhydrous ammonia and those 
generated from water dissociable ammonium salts, a distinction which is 
not present under environmental conditions. However, EPA is now 
concerned that without such a qualifier the regulated community might 
not realize that the aqueous ammonia from water dissociable ammonium 
salts is reportable under the ammonia listing. EPA guidance in response 
to inquires concerning what is reportable under the ammonia listing has 
been that aqueous ammonia from water dissociable ammonium salts is 
reportable under the listing. However, even after publishing this 
guidance in 1990 (55 FR 12148), EPA has continued to receive numerous 
inquires regarding what should be reported. Therefore, EPA proposes to 
add a qualifier to the ammonia listing to clarify that aqueous ammonia 
from water dissociable ammonium salts is reportable under the ammonia 
listing. EPA believes that modification of the ammonia listing to 
specify that the listing includes anhydrous ammonia and aqueous ammonia 
from water dissociable ammonium salts and other sources, would aid the 
regulated community in determining whether they are required to report 
and would eliminate any confusion over what is reportable under the 
ammonia listing. This modification would also include the proposal 
discussed above to limit reporting of aqueous ammonia to 10 percent of 
total aqueous ammonia. Upon finalization of this proposed rule, EPA 
will publish a revised guidance document for the ammonia listing.

        4.  Deletion of ammonium nitrate (solution). EPA is proposing to 
delete ammonium nitrate (solution) because the recent addition of the 
water dissociable nitrate compounds category (59 FR 61432, November 30, 

        5.  and reporting of aqueous ammonia from water dissociable ammonium 
salts under the ammonia listing negate the need for a separate listing 
for this chemical solution. EPA does not believe that this would be a 
significant change since the releases of ammonium nitrate (solution) 
would still be reported under the EPCRA section 313 listing for ammonia 
and the nitrate compounds category. Under the nitrate compounds 
category, the amount of ammonium nitrate in solution would be counted 
in threshold determinations for the category, but only the amount of 
nitrate ion would be counted in release and transfer determinations, 
therefore no double counting of releases would occur. This proposal 
would simply consolidate the reporting of ammonium nitrate (solution) 
under existing EPCRA section 313 listings. The original proposal 
discussed the reporting of water dissociable ammonium salts under the 
ammonia listing. Since ammonium nitrate is a water dissociable ammonium 
salt and since no loss of [[Page 16835]] information would result from 
this deletion, EPA believes that it is appropriate to add this proposal 
to this rulemaking.


V. Effective Dates


    The changes described in this amended proposal (with the exception 
of the deletion of ammonium nitrate (solution)) would be effective on 
the date of publication of the final rule, which EPA expects to occur 
prior to July 1, 1995. These changes would therefore be effective for 
the 1994 reporting year.
    Section 313(d)(4) of EPCRA provides, ``Any revision [to the section 
313 list] made on or after January 1 and before December 1 of any 
calendar year shall take effect beginning with the next calendar year. 
Any revision made on or after December 1 of any calendar year and 
before January 1 of the next calendar year shall take effect beginning 
with the calendar year following such next calendar year.'' EPA 
interprets this delayed effective date provision to apply only to 
actions that add chemicals to the section 313 list; EPA may, at its 
discretion, make deletions from the list and amendments to listings 
immediately effective.
    EPA believes that the purpose behind section 313(d)(4) is to allow 
facilities adequate planning time to incorporate newly added chemicals 
to their TRI release data collection processes. A facility would not 
need additional planning time not to report releases of a delisted 
chemical. Moreover, where EPA has determined that a chemical does not 
satisfy the criteria of section 313(d)(2)(A) through (C), no purpose is 
served by requiring facilities to collect release data or file release 
reports for that chemical, or, therefore, by leaving that chemical on 
the section 313 list for any additional period of time. Nothing in the 
legislative history suggests that section 313(d)(4) was intended to 
apply to deletions as well as additions. Thus, a reasonable 
construction of section 313(d)(4), given the overall purposes and 
structure of EPCRA--to provide the public with information about 
chemicals which meet the criteria for inclusion on the section 313 list 
-- is to apply the delayed effective date requirement only to additions 
to the list. This construction of section 313(d)(4) is also consistent 
with previous rules deleting chemicals from the section 313 list.
    An immediately effective date for the actions in this amended 
proposal is also consistent with 5 U.S.C. 553(d)(1), since a deletion 
from the section 313 list relieves a regulatory burden. EPA believes 
the combined effect of the changes in this amended proposal would be to 
reduce the burden by clarifying what is reportable under the ammonia 
listing and by simplifying the reporting requirements for ammonia. In 
addition, the proposal to require facilities to include 10 percent of 
total ammonia in aqueous solutions in threshold determinations might 
relieve some facilities from the obligation to report for aqueous 
ammonia.
    If EPA were to publish a final rule before July 1, 1995, the 
following effective dates and requirements would apply.

            

          1.  Deletion of ammonium sulfate (solution). The deletion of 
ammonium sulfate (solution) would be effective for the 1994 reporting 
year (reports due July 1, 1995).

          2.  Deletion of ammonium nitrate (solution). The deletion of 
ammonium nitrate (solution) would be effective for the 1995 reporting 
year (reports due July 1, 1996). EPA is proposing to delay the 
effective date of this provision to coincide with the effective date of 
the recently added water dissociable nitrate compounds category (59 FR 
61432, November 30, 1994). The requirement that aqueous ammonia from 
ammonium nitrate (solution) be reported under the ammonia listing as 10 
percent of total aqueous ammonia would also be effective for the 1995 
reporting year.

          3.  Reporting 10 percent of total aqueous ammonia. The requirement 
that 10 percent of total aqueous ammonia be reported under the ammonia 
listing for aqueous ammonia from all water dissociable ammonium salts 
(except ammonium nitrate (solution)) would be effective for the 1994 
reporting year. EPA believes that facilities that have been subject to 
record keeping requirements for ammonium sulfate (solution) already 
have the information needed to calculate threshold and release 
quantities for 10 percent total aqueous ammonia. Specifically, a 
facility would multiply the appropriate ammonium sulfate (solution) 
quantities by 2.7 percent, which represents 10 percent of the weight 
percent of aqueous ammonia from ammonium sulfate (solution).
    Facilities that currently report or make threshold determinations 
for the aqueous ammonia from other water dissociable ammonium salts may 
not be keeping the kind of information in their records that would 
allow them to calculate 10 percent of total aqueous ammonia from their 
un-ionized ammonia data. EPA recognizes that issuance of the final rule 
may come so late in the reporting year that some of these facilities 
may not be able to comply with this requirement before the July 1, 1995 
reporting date. Accordingly, for this one year, such facilities could 
continue to use the pH and temperature of their process and waste 
streams to estimate the quantities of un-ionized ammonia present for 
threshold and release determinations, respectively.
    Facilities that had already reported under the current requirements 
at the time the final rule is issued would not be required to resubmit 
their reports under the new requirements. They could, however, withdraw 
their reports if they did not meet the threshold for ammonia under the 
revised ammonia listing.


VI. Request for Public Comment


    EPA requests public comment on the actions discussed in this 
amended proposed rule. Comments should be submitted to the address 
listed under the ADDRESSES unit. All comments must be received on or 
before May 3, 1995. In developing the final rule, EPA will consider 
comments submitted in response to this amended proposal and comments 
previously submitted on the original proposal.


VII. Rulemaking Record


    The record supporting the original proposal and proposed amendment 
is contained in docket number OPPTS-400032. All documents, including an 
index of the docket, are available in the TSCA Nonconfidential 
Information Center (NCIC), also known as, TSCA Public Docket Office 
from noon to 4 p.m., Monday through Friday, excluding legal holidays. 
TSCA NCIC is located at EPA Headquarters, Rm. NE-B607, 401 M St., SW., 
Washington, DC 20460.


VIII. References


    (1) Data from EPA's STORET water quality data base as tabulated in, 
Industry Comments for the U.S. EPA Science Advisory Board Ecological 
Processes and Effects Committee on Delisting of Ammonium Sulfate Under 
EPCRA Section 313 and Reporting of Ammonia Releases, December 16, 1994, 
by BP Chemicals Inc., Monsanto, and Sterling Chemicals.
    (2) Uwe Borgmann, Chronic Toxicity of Ammonia to the Amphipod 
Hyalella azteca; Importance of Ammonium Ion and Water Hardness, 
Environmental Pollution, 86 (1994) 329-335.
    (3) Summary Review of Health Effects Associated with Ammonia, U.S. 
EPA Office of Health and Environmental Assessment, EPA/600/8-89/052F 
June 1989.
    (4) U.S. EPA, OPPT, EETD, EAB, Water Quality Modeling of Ammonium 
Sulfate (solution) and Ammonium Nitrate (solution) Toxic Release 
[[Page 16836]] Inventory (TRI) Surface Water Releases and Transfers to 
POTWs, March 13, 1995.
    (5) Letter of February 2, 1995 to Carol M. Browner, Administrator 
U.S. EPA from Dr. Genevieve Matanoski, Chair, Executive Committee, 
Science Advisory Board.


IX. Regulatory Assessment Requirements


A. Executive Order 12866


    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to review by the Office of Management and Budget 
(OMB) and the requirements of the Executive Order. Under section 3(f), 
the order defines a ``significant regulatory action'' as an action 
likely to lead to a rule (1) Having an annual effect on the economy of 
$100 million or more, or adversely and materially affecting a sector of 
the economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or communities 
(also referred to as ``economically significant''); (2) creating 
serious inconsistency or otherwise interfering with an action taken or 
planned by another agency; (3) materially altering the budgetary 
impacts of entitlements, grants, user fees, or loan programs; or (4) 
raising novel legal or policy issues arising out of legal mandates, the 
President's priorities, or the principles set forth in this Executive 
Order. Pursuant to the terms of this Executive Order, it has been 
determined that this amended proposed rule is not ``significant'' and 
therefore not subject to OMB review.


B. Regulatory Flexibility Act


    Under the Regulatory Flexibility Act of 1980, the Agency must 
conduct a small business analysis to determine whether a substantial 
number of small entities would be significantly affected by a proposed 
rule. Because the amended proposed rule does not create any new 
requirements and consolidates other requirements, it would not 
significantly affect facilities, including small entities.


C. Paperwork Reduction Act


    This amended proposed rule does not result in any new information 
collection requirements subject to the provisions of the Paperwork 
Reduction Act of 1980, 44 U.S.C. 3501 et seq.


List of Subjects in 40 CFR Part 372


    Environmental protection, Chemicals, Community right-to-know, 
Reporting and recordkeeping requirements, and Toxic chemicals.
    Dated: March 29,1995.


Susan H. Wayland,
Acting Assistant Administrator, Office of Prevention, Pesticides and 
Toxic Substances.


    Therefore it is proposed that, 40 CFR part 372 be amended as 
follows:


PART 372--[AMENDED]


              

            1.  The authority citation for part 372 would continue to read as 
follows:


    Authority: 42 U.S.C. 11023 and 11048.



Sec. 372.65  [Amended]


    2. Sections 372.65(a) and (b) are amended by removing the entire 
entry for ammonium sulfate (solution) and ammonium nitrate (solution) 
and by adding the following language to the ammonia listing ``includes 
anhydrous ammonia and aqueous ammonia from water dissociable ammonium 
salts and other sources; 10 percent of total aqueous ammonia is 
reportable under this listing'' under paragraph (a) and removing the 
entire CAS No. entry for 7783-20-2 and 6484-52-2 under paragraph (b).


[FR Doc. 95-8202 Filed 3-30-95; 1:29 pm]
BILLING CODE 6560-50-F

 
 

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