MEMORANDUM

To: Tina Ndoh, U.S. EPA/OAQPS/SPPD - Minerals and Manufacturing Group

From: Eastern Research Group, Inc. 

Date: August 20, 2014

Subject: Emissions Data Used in Residual Risk Modeling: Phosphoric Acid and Phosphate 

Fertilizer Production Source Categories

1.0 INTRODUCTION

The U.S. Environmental Protection Agency (EPA), under section 112 of the Clean Air 

Act (CAA), is required to establish maximum achievable control technology (MACT) standards 

for phosphoric acid manufacturing plants (40 CFR part 63, subpart AA) and phosphate fertilizer 

production plants (40 CFR part 63, subpart BB) source categories. Under section 112(d)(6), EPA 

must review, and, if necessary, revise the MACT standards based on a residual risk and 

technology review (RTR). This memorandum describes the methodology used to develop the 

RTR modeling file and baseline emissions for phosphoric acid manufacturing plants and 

phosphate fertilizer production plants. This memorandum is organized as follows:

2.0 Emissions Testing Data Extraction and Compilation 

3.0 Estimated Emissions for Point Sources Not Tested 

4.0 Estimated Emissions for Fugitive Sources Not Tested

5.0 Speciation of Emissions

6.0 Acute Emissions Multiplier

7.0 Estimating MACT-allowable emissions

8.0 Incorporation of Facility Wide National Emissions Inventory Category Data

9.0 Emission Corrections to RTR Modeling File

10.0 Additional Emissions Testing

11.0 Comparison of Facility Emissions to Major Source Thresholds

Appendix A – Excel file “Emission_Data_Phosphate_Sector.xlsx”

EPA used results of stack testing required by an April 13, 2010 section 114 survey and 

testing request to inform the RTR modeling file and baseline emissions for phosphoric acid 

manufacturing plants and phosphate fertilizer production plants. Results of stack testing required 

by a January 24, 2014 section 114 survey and testing request were not used in the development

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of the RTR modeling file and baseline emissions for phosphoric acid manufacturing plants and 

phosphate fertilizer production plants; except for Hg, as noted in section 9.0. Sections 2.0 

through 9.0 and 11.0 of this memorandum only apply to the emissions data received from the 

April 13, 2010 section 114 survey and testing request. Refer to section 10.0 of this memorandum 

for further discussion about the emissions data received from the January 24, 2014 section 114 

survey and testing request.

2.0 EMISSIONS TESTING DATA EXTRACTION AND COMPILATION

The survey responses, test reports received, and a file that contains the standardized data 

received by EPA is available in the docket for this action. The details of the survey, as well as 

standardization of the data received by EPA, are described in a separate memorandum.1 A 

compilation of the emissions test data received is available in Appendix A-1; see those data 

labeled as “Tested” under the “Tested or Estimated” column. The production and feed rates for 

each process unit during the emissions tests are provided in Appendix A-2.

The test data submitted by facilities in response to the section 114 were used to calculate 

hourly emission rates by multiplying the standardized concentration results by the reported 

volumetric flow rates for each emission point that was tested. The corresponding annual hours of 

production reported by facilities in the section 114 survey were then used to estimate the annual 

emissions for each pollutant and emission point tested. Facilities generally conducted three test 

runs for each method and pollutant concentration. Therefore, the average of the test runs was 

used to estimate the annual baseline emissions for each emission point at each facility. 

3.0 ESTIMATED EMISSIONS FOR POINT SOURCES NOT TESTED

As described in a separate memorandum1

, facilities were allowed to test one process in a 

group of identical processes as long as the tested process was representative of those which were 

not tested. For those emission points and processes which were not tested, a ratio based on 

production and annual operating hours was used to determine their estimated emissions. 

For tested emission points the hourly production rates during the test were provided in 

test reports, and the operating hours were provided in the section 114 survey. Note that for 

emission points at the same process unit, operating hours were assumed to be identical. In certain 

situations, hourly production rates were not used. If the production rate during the test was not 

available, the annual production provided in the survey was used instead; in these cases 

operating hours were not used in the equation. For one facility the product flow rates (gallons per 

minute) were available and the flow rates could be attributed to specific emission points. It was 

determined that flow rates would provide the most accurate method for comparison. In this 

instance the operating hours for both units were assumed to be equal and a ratio of the flow rates 

were used to calculate emissions. A brief description of the emission point which was 

determined to be representative and the production data used to calculate emissions for nontested emission points is located in the column labeled “Data Source” in Appendix A-1; refer to 

the emission points labeled as “Estimated” under the “Tested or Estimated” column.

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Estimated Mercury Emissions for PCS Aurora

Certain emission points at PCS Aurora were not tested for mercury, but after review of 

the available emissions data it was determined that an estimated mercury emissions value was 

necessary. These emission points were associated with ammonium phosphate fertilizer (APF)

production, purified phosphoric acid (PAP) production, and superphosphoric acid (SPA) 

production. For emission points 302 and 303 (APF production), mercury emissions were 

estimated using available total mercury data from APF processes at other facilities. Data from 

eight facilities were used. Emission points 330, 331, and 332 are SPA lines at PCS Aurora and 

were estimated using total mercury data from SPA processes at three facilities. The SPA data 

from Simplot Don-Pocatello were not used because Simplot Don-Pocatello uses a proprietary 

process which was not considered representative. For each emission point related to APF or SPA 

production at the non-Aurora facilities the total mercury emissions (in tons per year) were 

divided by the phosphorus pentoxide (P2O5) production rate (tons per year) to calculate a tons of 

total mercury per ton of P2O5 factor. An average factor using the applicable emission points for 

APF production was calculated and a separate average factor for SPA processes was calculated. 

Each of these factors was then applied to the appropriate emission points at PCS Aurora. The 

details to calculate the average factors are provided in Appendix A-3. 

The emission points at the PAP line were also not tested. PCS Aurora was the only 

facility with a solvent extraction PAP line so representative data were not available. Mercury 

emissions from this process are expected to be low because vent temperatures are low (25 

degrees C). Therefore, emissions were assumed to be at or near the method detection level. To 

estimate total mercury emissions for PAP emission points 502, 504, and 506 the average of all 

non-detect data reported for total mercury using the Ontario Hydro method for all facilities was 

calculated (grains per dry standard cubic foot). The non-detect calculations are also available in 

Appendix A-3. This average concentration value was then multiplied by the flow rate for each 

PAP emission point, as reported in stack test data for other pollutants, and the annual operating 

hours from the survey. After determining the estimated total mercury for the PCS Aurora 

emission points the mercury was speciated according to the procedures described in section 5.0. 

4.0 ESTIMATED EMISSIONS FOR FUGITIVE SOURCES NOT TESTED

Gypsum Dewatering Stack and Cooling Pond Emissions Estimate

For gypsum dewatering stacks and cooling ponds, low, medium, and high estimated 

emission factors (in tons per acre per year) were calculated for hydrogen fluoride. These 

emission factors were derived from open path tunable diode laser or open path fourier transform 

infrared with radial plume mapping tests performed at six different facilities in the U.S. and 

Canada. These test reports are available in the docket for this action. Each of these test reports 

was reviewed and the emission factor data were assigned to gypsum dewatering stacks or cooling 

ponds. Four test reports included data for cooling ponds, and four test reports included data for 

the gypsum dewatering stack and associated gypsum pond area. The test report emission factor 

data specific to gypsum dewatering stacks were used to develop gypsum dewatering stack 

emission factors. Similarly, cooling pond emission factors were used to develop corresponding 

emission factors. The medium emission factor for a cooling pond or a gypsum dewatering stack

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was calculated as the average of all data in the category. For the high estimate, the low outlier 

hydrogen fluoride emission factor values were removed from the estimate. For the low estimate, 

high hydrogen fluoride outlier emission factors were removed. See Appendices A-4 and A-5 for 

details on the emission factor data that were available and the resulting low, medium, and high 

emission factors. 

The high, low, and medium emission factors were then applied to each facility to estimate 

fugitive emissions for each facility. If a facility had specific test data available, and these data 

were lower than the low emission factor calculated, these facility specific data were substituted 

for the low emission factor. Refer to Appendix A-6 for more information regarding the specific 

emission factors applied to each facility. Note that Mosaic New Wales did have facility specific 

data available, which was close to the medium value; in this instance the medium factors were 

used. 

To apply the emission factor, an estimate of the total acreage of all gypsum dewatering 

stacks or cooling ponds at each facility was necessary. These data were provided in the section 

114 survey on Form C-1-b. In most instances the summation of the provided areas were used to 

calculate the actual emissions (tons per year). For a limited number of instances, facilities did not 

provide acreage data for either a cooling pond or gypsum dewatering stack, and when this 

occurred the area was estimated using Google EarthTM. Documentation of when an acreage 

estimate from Google EarthTM was used is provided in Appendix A-6. For closed gypsum 

dewatering stack areas, the estimated area of the associated pond observed on Google EarthTM

was used, rather than the area of the entire gypsum dewatering stack, and the gypsum dewatering 

stack emission factor was applied. The equation below shows the calculation performed for each 

gypsum dewatering stack or cooling pond to determine its actual emissions:

Actual emissions (tons/year) = emission factor (tons/acre/year) * acres

Cooling Towers

Emissions estimates for cooling towers were determined using data provided by each of 

the facilities that operated cooling towers which used water containing fluorides. Cooling tower 

emissions were estimated for four facilities. Three of these facilities appear to use process water 

with relatively high levels of fluoride as the cooling tower water source. One additional facility 

has a relatively low permitted level of fluoride emissions but was included in the data set due to 

the established permit limits. Emissions were estimated from information available in test reports 

or from the total fluoride or hydrogen fluoride emissions limits in the Title V permit. For two 

cooling towers, total fluoride emissions data were provided and it was assumed that 93 percent of 

the total fluoride emissions were attributable to hydrogen fluoride. The permitted emissions 

provided in pounds per day were converted to tons per year using 365 operating days. Details 

regarding the exact method used for each cooling tower are provided Appendix A-7.

Contribution to Source Category Emissions

The largest sources of the hazardous air pollutant (HAP) HF that were identified from 

Phosphoric Acid Manufacturing and Phosphate Fertilizer Production facilities are fugitive 

emission sources, which include gypsum dewatering stacks, cooling ponds, and cooling towers. 

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See Table 1 for the fugitive emissions summary by facility. Fugitive emissions from these three 

sources account for approximately 95 percent of total HF emissions for the Phosphoric Acid 

Manufacturing and Phosphate Fertilizer Production source categories. Fugitive emissions from 

these three sources account for more than 96 percent of total HF emissions for the Phosphoric 

Acid source category and gypsum dewatering stacks and cooling ponds are the two predominant 

sources. 

Table 1. Fugitive HF emissions summary for each facility (medium emission factor)(a).

Facility

Tons HF per year

Gypsum 

Dewatering 

Stacks

Cooling Pond Cooling Tower Total

Agrium Nu-West 45 24 N/A 69

CFI Plant City 78 43 N/A 121

Mississippi Phosphates 15 68 N/A 83

Mosaic Bartow 65 143 N/A 208

Mosaic New Wales 61 156 N/A 218

Mosaic Riverview 101 174 N/A 275

Mosaic Uncle Sam 40 34 N/A 74

PCS Aurora 69 204 5 278

PCS Geismar 49 16 17 83

PCS White Springs 155 298 N/A 453

Simplot Don-Pocatello 88 N/A 116 204

Simplot Rock Springs 85 N/A(b) 4 89

Total 851 1,161 143 2,155

Note:

(a) A range of emission estimates was developed because there was a high amount of variability in the 

submitted emissions testing data. This chart presents the mid range estimates.

(b) Although Simplot Rock Springs does use cooling ponds, sufficient data was not provided to develop an 

emission estimate.

5.0 SPECIATION OF EMISSIONS

Mercury

Facilities reported total and elemental mercury using EPA Method 30B and Hg ASTMD6784-02 (i.e., the Ontario Hydro method) respectively. Where facilities reported elemental or 

total mercury results using both test methods, only the Ontario Hydro results were included in 

the modeling file calculations.

Mercury was speciated in the final modeling file into elemental gaseous mercury, 

gaseous divalent mercury, and particulate divalent mercury using the following procedure. If a 

facility reported both elemental and total mercury, the difference of the two was calculated. It 

was assumed that half of the difference was gaseous divalent mercury, the balance being 

particulate divalent mercury. If a facility only reported total mercury or elemental mercury, it 

5
was assumed that 80 percent of the total mercury was elemental mercury, and the gaseous 

divalent and particulate divalent fractions were each ten percent of the total mercury. 

Chromium

Facilities reported total chromium and hexavalent chromium using EPA Method 29 and 

SW-846 Method 0061 HC respectively. It was assumed that the difference of the total chromium 

and hexavalent chromium was trivalent chromium. In instances where the total chromium 

concentration was less than the hexavalent chromium concentration, it was assumed that all 

chromium was hexavalent, and only the test value for hexavalent chromium was used for the 

modeling file. 

Fluorides

Facilities reported total fluorides and hydrogen fluoride using EPA Method 13B and EPA 

Method 26A respectively. A majority of facilities reported both types of fluoride for each 

emission point. However; in a few instances data were only available for total fluorides. A

conservative one to one molar ratio was used to determine the amount of hydrogen fluoride for 

instances where only data for total fluorides were available. 

6.0 ACUTE EMISSIONS MULTIPLIER

In order to provide maximum emissions for the acute exposure analysis, a multiplier of 

10 times the actual emissions was used for point sources. EPA uses a multiplier of 10 to predict 

worst case emissions during a process upset or control device malfunction. 

For fugitive emissions of hydrogen fluoride from gypsum dewatering stacks, cooling 

ponds and cooling towers, an acute multiplier of one was used for all sources. Fugitive emissions 

are not expected to increase with an increase in production rate, or increase significantly during a 

process upset. For cooling ponds, because of their general homeostatic nature, changes with time 

are expected to be minor. Emissions are expected to be higher during daylight hours. Test data 

for these sources were obtained during the spring and summer seasons, and during daylight 

hours, and therefore emissions would not be expected to increase significantly beyond the levels 

measured during the tests. The range of estimates developed (high, medium, and low) is 

expected to account sufficiently for any changes to emissions as ambient conditions change. 

7.0 ESTIMATING MACT-ALLOWABLE EMISSIONS

To calculate allowable emissions for hydrogen fluoride, metals, and methyl isobutyl 

ketone (MIBK) an appropriate multiplier to the actual emissions was calculated. The multiplier 

was based on the ratio of permit limits to actual emissions for hydrogen fluoride. For metals and 

MIBK, the multiplier was based on a ratio of permitted production to actual production. 

Hydrogen Fluoride - Point Sources

To calculate the hydrogen fluoride multiplier to determine allowable emissions, the total 

fluoride limit from the permit was compared to the actual total fluoride emissions which were 

calculated using stack test data. The permit for each facility was examined and the total fluoride 

6
limit for each process unit was documented. Using the permitted total fluoride limit, a ratio of 

permitted to actual emissions was calculated using the following equation:

Hydrogen fluoride multiplier = permitted total fluoride limit (tons/year) / actual total 

fluoride annual emissions (tons/year)

Total fluoride limits are on a process unit level, which may encompass multiple 

emissions. For process units which have multiple emission points the actual total fluoride 

emissions would be the sum of annual total fluoride emissions for each applicable emission 

point.

Metals and Methyl Isobutyl Ketone Multiplier

To calculate allowable emissions for metals and MIBK data, a different procedure was 

necessary since permit limits are not provided for metals or MIBK. Actual emissions were scaled 

up in proportion to the ratio of permitted production to actual production. The following equation 

was used:

Metals multiplier = (permitted production (tons/hour) * 8760 operating hours) / (actual 

production (tons/hour) * actual operating hours)

Each production value generally corresponds to the P2O5 production rate. The actual 

production in tons per hour as reported for the stack test conducted for the section 114 was used 

as the actual hourly production rate. Actual operating hours were provided in the section 114

responses. For some process units, the production rate during the stack test was not available. For 

these process units, the annual production provided in the section 114 survey Excel files was 

used. Note that if annual production was used, then actual operating hours were not used. The 

metals and MIBK multipliers calculated to determine allowable emissions for each emission 

point are provided in Appendix A-8.

Final Allowable Calculation

The allowable emissions were then calculated for each pollutant using the appropriate 

multiplier (either the fluoride or metals multiplier) and the actual emissions. The allowable 

emissions were calculated using the following equation:

Allowable emissions (tons/yr) = actual emissions (tons/yr) * multiplier

8.0 INCORPORATION OF FACILITY WIDE NATIONAL EMISSIONS 

INVENTORY CATEGORY DATA 

Three modeling files were developed for use in the risk review; a file with data for only 

the Phosphoric Acid Manufacturing source category (MACT code 1411), a file with data for 

only the Phosphate Fertilizer Production source category (MACT code 1410), and a facility wide 

modeling file. Data that were submitted for the section 114 request were used as primary data. 

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To create the facility wide modeling file additional emissions data that were not submitted for 

the section 114 request were extracted from the 2005 National Emissions Inventory (NEI). 

NEI data were extracted for all records for all pollutants in the database for the facilities 

identified in this analysis. The records were sorted by MACT code. The standard classification 

code (SCC) codes for the records extracted and sorted were reviewed to identify any mislabeled 

data, and data were re-assigned to a MACT (or non-MACT) category where appropriate. For the 

MACT records in the NEI, records were removed for any pollutants that were included in the test 

results submitted as part of the section 114 request and the data submitted by the facilities as 

described in this memo was substituted. 

The 2008 NEI was also reviewed for pollutants that were not reported in the 2005 NEI; 

any records identified as missing in the 2005 NEI were added from the 2008 NEI data. 

9.0 EMISSION CORRECTIONS TO RTR MODELING FILE

After the RTR modeling file was compiled and the risk assessments were performed, 

certain corrections to the emissions data were identified. These corrections were reviewed on a 

case-by-case basis to determine if they would impact the risk results. In each instance, it was 

determined the RTR modeling file did not need to be revised because the actual emissions for 

each facility decreased, which would result in lower human and ecological risk, or had a 

negligible increase which would not affect human and ecological risk. Since the original 

modeled emissions did not present any risks that were determined to be unacceptable, lower or 

negligibly changed emissions values would not need remodeling as the acceptability is already 

known. Each of the identified corrections are discussed here. Note that while these emission 

corrections were not incorporated into the modeling file, they were used when other emissions 

analyses were conducted, such as the Technology Review.

PCS Aurora Calciner Emissions (EP 201-206)

Emissions for PCS Aurora’s calciners were calculated using emissions data from the one 

calciner tested (EP-203). The emissions for each non-tested calciner were then calculated using 

annual production data. An incorrect annual production value was used for the tested calciner 

(EP-203) so the estimated emissions for the other five calciners are high. The corrected 

emissions for all pollutants were reduced by approximately 46%. Table 2 shows the specific 

correction factor that can be applied to each pollutant emissions value for calciners EP-201, 202, 

204, 204, and 206 in the modeling file to determine the corrected emissions. 

Table 2. Emission Correction Summary for PCS Aurora’s Calciners.

Facility 

Name

Process 

Unit

Emission 

Point

Original 

Production 

Value

CORRECTED 

Production 

Value

Correction 

Factor

PCS Aurora 203 EP-203 250,842 365,695 0.6859

PCS Aurora MAP/DAP Emissions (EP-302 and 303)

As discussed in section 3.0 above, mercury was not tested for two APF emission points 

(EP-302 and EP-303) and an estimate was made using mercury data from all APF processes. 

8
Based on a review of data, the mercury emissions for both emission points were overestimated 

because several of the production rates and operating hours were incorrect for the non-PCS 

Aurora APF processes. Correcting these values resulted in a change of the average APF Hg 

emission factor from 2.96E-09 tons Hg per ton of P2O5 to 2.87 tons Hg per ton of P2O5 (see 

Appendix A-2 for the development of the APF Hg emission factor and its application to calculate 

Hg emissions). For EP-302 and EP-303 the corrected emissions would be reduced by 3%. 

Mosaic New Wales (P-5, EP-06)

Emission point EP-06 at process unit P-5 was not tested, and emissions data from a 

representative emission point was used to estimate emissions. However, the production rate used 

to scale emissions for EP-06 was misinterpreted as a P2O5 basis. The corrected emissions for all 

pollutants would be reduced by approximately 62%. Table 3 shows the specific correction factor 

that can be applied to each pollutant emissions value for EP-06 in the modeling file to determine 

the corrected emissions.

Table 3. Emission Correction Summary for Mosaic New Wales.

Facility Name Process 

Unit

Emission 

Point

Original 

Production 

Value

CORRECTED 

Production 

Value

Correction 

Factor

Mosaic New Wales P-5 EP-06 118.3 44.62 0.3772

Mosaic Riverview (P-12, EP-4; P-13, EP-5 and EP-6)

Certain emission points (P-12, EP-4; P-13, EP-5 and EP-6) were not tested, and 

emissions data from a representative emission point was used to estimate emissions. However, 

the production rate used to scale emissions for each of the three emission points was 

misinterpreted as a P2O5 basis. The corrected emissions for all pollutants would be reduced by 

approximately 34% or 54% for each emission point. Table 4 shows the specific correction factor 

that can be applied to each pollutant emissions value for EP-4, EP-5, and EP-6 in the modeling 

file to determine the corrected emissions.

Table 4. Emission Correction Summary for Mosaic Riverview.

Facility Name Process 

Unit

Emission 

Point

Original 

Production 

Value

CORRECTED 

Production 

Value

Correction 

Factor

Mosaic Riverview P-12 EP-4 126.33 83.59 0.6617

Mosaic Riverview P-13 EP-5 133.83 91.66 0.4632

Mosaic Riverview P-13 EP-6 133.83 91.66 0.4632

Mercury Ontario-Hydro Method QA

A detailed review of the Ontario-Hydro Method (OH) Hg data was conducted that 

identified certain issues. Notably, there was a discrepancy in the manner in which testing 

companies handled field blanks or non-detect data. Each facility’s OH Hg data were examined 

and corrected as appropriate so that a consistent protocol was followed. The resulting change in 

emissions for each facility is provided in Table 5. 

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Table 5. Emission Corrections Resulting from Ontario-Hydro Method QA.

Facility Name Process 

Unit

Emission 

Point Pollutant

Hg 

Emissions

from 

Modeling 

File (TPY)

New Hg 

Emissions 

from QA 

(TPY)

Percent 

Change

Agrium Nu-West Gran EP-6 Elemental Gaseous Hg 2.99E-05 4.20E-05 41%

Agrium Nu-West Gran EP-6 Gaseous Divalent Hg 9.88E-06 1.67E-05 69%

Agrium Nu-West Gran EP-6 Particulate Divalent Hg 9.88E-06 1.67E-05 69%

Agrium Nu-West SPA 2Filt Elemental Gaseous Hg 6.51E-07 9.34E-07 43%

Agrium Nu-West SPA 2Filt Gaseous Divalent Hg 2.32E-07 3.77E-07 63%

Agrium Nu-West SPA 2Filt Particulate Divalent Hg 2.32E-07 3.77E-07 63%

Agrium Nu-West SPA 3131 Elemental Gaseous Hg 7.08E-07 1.02E-06 43%

Agrium Nu-West SPA 3131 Gaseous Divalent Hg 2.53E-07 4.11E-07 63%

Agrium Nu-West SPA 3131 Particulate Divalent Hg 2.53E-07 4.11E-07 63%

Agrium Nu-West SPA 3241 Elemental Gaseous Hg 9.38E-07 1.35E-06 43%

Agrium Nu-West SPA 3241 Gaseous Divalent Hg 3.35E-07 5.44E-07 63%

Agrium Nu-West SPA 3241 Particulate Divalent Hg 3.35E-07 5.44E-07 63%

Agrium Nu-West SPA 6101 Elemental Gaseous Hg 5.30E-07 9.15E-07 73%

Agrium Nu-West SPA 6101 Gaseous Divalent Hg 6.62E-08 4.52E-07 582%

Agrium Nu-West SPA 6101 Particulate Divalent Hg 6.62E-08 4.52E-07 582%

Agrium Nu-West SPA EP-283 Elemental Gaseous Hg 5.92E-07 7.48E-07 26%

Agrium Nu-West SPA EP-283 Gaseous Divalent Hg 7.67E-08 1.78E-07 132%

Agrium Nu-West SPA EP-283 Particulate Divalent Hg 7.67E-08 1.78E-07 132%

Agrium Nu-West SPA EP-522 Elemental Gaseous Hg 6.94E-07 1.22E-05 1662%

Agrium Nu-West SPA EP-522 Gaseous Divalent Hg 3.05E-07 3.03E-06 895%

Agrium Nu-West SPA EP-522 Particulate Divalent Hg 3.05E-07 3.03E-06 895%

Agrium Nu-West SPA EP-71 Elemental Gaseous Hg 5.96E-05 8.38E-05 40%

Agrium Nu-West SPA EP-71 Gaseous Divalent Hg 1.89E-05 3.42E-05 81%

Agrium Nu-West SPA EP-71 Particulate Divalent Hg 1.89E-05 3.42E-05 81%

CFI Plant City A-DAP A-DAP Elemental Gaseous Hg 6.60E-05 8.33E-05 26%

CFI Plant City A-DAP A-DAP Gaseous Divalent Hg 3.58E-06 3.87E-06 8%

CFI Plant City A-DAP A-DAP Particulate Divalent Hg 3.58E-06 3.87E-06 8%

CFI Plant City A-PAP A-PAP Elemental Gaseous Hg 1.66E-04 1.94E-04 17%

CFI Plant City A-PAP A-PAP Gaseous Divalent Hg 5.14E-06 6.75E-06 31%

CFI Plant City A-PAP A-PAP Particulate Divalent Hg 5.14E-06 6.75E-06 31%

CFI Plant City B-PAP B-PAP Elemental Gaseous Hg 2.98E-04 3.49E-04 17%

CFI Plant City B-PAP B-PAP Gaseous Divalent Hg 9.22E-06 1.21E-05 31%

CFI Plant City B-PAP B-PAP Particulate Divalent Hg 9.22E-06 1.21E-05 31%

CFI Plant City X-MAP X-MAP Elemental Gaseous Hg 3.75E-03 2.30E-03 -39%

CFI Plant City X-MAP X-MAP Gaseous Divalent Hg 1.77E-05 1.43E-05 -19%

CFI Plant City X-MAP X-MAP Particulate Divalent Hg 1.77E-05 1.43E-05 -19%

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Facility Name Process 

Unit

Emission 

Point Pollutant

Hg 

Emissions

from 

Modeling 

File (TPY)

New Hg 

Emissions 

from QA 

(TPY)

Percent 

Change

CFI Plant City Y-MAP Y-MAP Elemental Gaseous Hg 3.04E-03 3.43E-03 13%

CFI Plant City Y-MAP Y-MAP Gaseous Divalent Hg 5.84E-05 6.64E-05 14%

CFI Plant City Y-MAP Y-MAP Particulate Divalent Hg 5.84E-05 6.64E-05 14%

CFI Plant City Z-MAP Z-MAP Elemental Gaseous Hg 3.75E-03 2.30E-03 -39%

CFI Plant City Z-MAP Z-MAP Gaseous Divalent Hg 1.77E-05 1.43E-05 -19%

CFI Plant City Z-MAP Z-MAP Particulate Divalent Hg 1.77E-05 1.43E-05 -19%

Mosaic New Wales P-1 EP-22 Elemental Gaseous Hg 2.57E-06 2.46E-06 -4%

Mosaic New Wales P-1 EP-22 Gaseous Divalent Hg 3.21E-07 3.08E-07 -4%

Mosaic New Wales P-1 EP-22 Particulate Divalent Hg 3.21E-07 3.08E-07 -4%

Mosaic New Wales P-2 EP-05 Elemental Gaseous Hg 3.70E-04 4.01E-04 8%

Mosaic New Wales P-2 EP-05 Gaseous Divalent Hg 4.62E-05 5.01E-05 8%

Mosaic New Wales P-2 EP-05 Particulate Divalent Hg 4.62E-05 5.01E-05 8%

PCS Aurora 406 EP-408 Elemental Gaseous Hg 1.81E-06 2.93E-06 62%

PCS Aurora 406 EP-408 Gaseous Divalent Hg 5.09E-07 1.41E-06 178%

PCS Aurora 406 EP-408 Particulate Divalent Hg 5.09E-07 1.41E-06 178%

PCS White Springs 20 20.01 Elemental Gaseous Hg 1.15E-04 1.03E-04 -11%

PCS White Springs 20 20.01 Gaseous Divalent Hg 1.44E-05 6.13E-06 -57%

PCS White Springs 20 20.01 Particulate Divalent Hg 1.44E-05 6.13E-06 -57%

PCS White Springs 20 20.01 Elemental Gaseous Hg 8.70E-05 1.03E-04 18%

PCS White Springs 20 20.01 Gaseous Divalent Hg 1.09E-05 6.13E-06 -44%

PCS White Springs 20 20.01 Particulate Divalent Hg 1.09E-05 6.13E-06 -44%

PCS White Springs 32 EP-32 Elemental Gaseous Hg 2.57E-04 2.93E-04 14%

PCS White Springs 32 EP-32 Gaseous Divalent Hg 3.21E-05 1.36E-05 -57%

PCS White Springs 32 EP-32 Particulate Divalent Hg 3.21E-05 1.36E-05 -57%

PCS White Springs 36 34.01 Elemental Gaseous Hg 1.43E-04 1.38E-04 -3%

PCS White Springs 36 34.01 Gaseous Divalent Hg 1.78E-05 7.01E-06 -61%

PCS White Springs 36 34.01 Particulate Divalent Hg 1.78E-05 7.01E-06 -61%

PCS White Springs 69 69.01 Elemental Gaseous Hg 2.42E-04 2.52E-04 4%

PCS White Springs 69 69.01 Gaseous Divalent Hg 3.03E-05 1.93E-05 -36%

PCS White Springs 69 69.01 Particulate Divalent Hg 3.03E-05 1.93E-05 -36%

PCS White Springs 70 70.01 Elemental Gaseous Hg 1.86E-04 1.80E-04 -3%

PCS White Springs 70 70.01 Gaseous Divalent Hg 2.33E-05 9.16E-06 -61%

PCS White Springs 70 70.01 Particulate Divalent Hg 2.33E-05 9.16E-06 -61%

PCS White Springs EU 008 EP-8 Elemental Gaseous Hg 1.70E-04 1.94E-04 14%

PCS White Springs EU 008 EP-8 Gaseous Divalent Hg 2.12E-05 9.01E-06 -57%

PCS White Springs EU 008 EP-8 Particulate Divalent Hg 2.12E-05 9.01E-06 -57%

Simplot Don-Pocatello P-1 EP-101 Elemental Gaseous Hg 1.11E-05 4.50E-06 -59%

11
Facility Name Process 

Unit

Emission 

Point Pollutant

Hg 

Emissions

from 

Modeling 

File (TPY)

New Hg 

Emissions 

from QA 

(TPY)

Percent 

Change

Simplot Don-Pocatello P-1 EP-101 Gaseous Divalent Hg 1.38E-06 6.01E-07 -56%

Simplot Don-Pocatello P-1 EP-101 Particulate Divalent Hg 1.38E-06 6.01E-07 -56%

Simplot Don-Pocatello P-1 EP-102 Elemental Gaseous Hg 8.33E-05 5.03E-05 -40%

Simplot Don-Pocatello P-1 EP-102 Gaseous Divalent Hg 1.04E-05 1.10E-05 6%

Simplot Don-Pocatello P-1 EP-102 Particulate Divalent Hg 1.04E-05 1.10E-05 6%

Simplot Don-Pocatello P-1 EP-103 Elemental Gaseous Hg 4.75E-06 2.21E-06 -53%

Simplot Don-Pocatello P-1 EP-103 Gaseous Divalent Hg 5.94E-07 1.72E-06 191%

Simplot Don-Pocatello P-1 EP-103 Particulate Divalent Hg 5.94E-07 1.72E-06 191%

Simplot Don-Pocatello P-2 EP-201 Elemental Gaseous Hg 5.76E-05 2.21E-05 -62%

Simplot Don-Pocatello P-2 EP-201 Gaseous Divalent Hg 7.20E-06 1.33E-05 84%

Simplot Don-Pocatello P-2 EP-201 Particulate Divalent Hg 7.20E-06 1.33E-05 84%

Simplot Don-Pocatello P-2 EP-202 Elemental Gaseous Hg 5.76E-05 2.21E-05 -62%

Simplot Don-Pocatello P-2 EP-202 Gaseous Divalent Hg 7.20E-06 1.33E-05 84%

Simplot Don-Pocatello P-2 EP-202 Particulate Divalent Hg 7.20E-06 1.33E-05 84%

Simplot Don-Pocatello P-3 EP-301 Elemental Gaseous Hg 1.19E-05 6.85E-06 -42%

Simplot Don-Pocatello P-3 EP-301 Gaseous Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-3 EP-301 Particulate Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-3 EP-302 Elemental Gaseous Hg 1.19E-05 6.85E-06 -42%

Simplot Don-Pocatello P-3 EP-302 Gaseous Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-3 EP-302 Particulate Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-3 EP-303 Elemental Gaseous Hg 1.19E-05 6.85E-06 -42%

Simplot Don-Pocatello P-3 EP-303 Gaseous Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-3 EP-303 Particulate Divalent Hg 1.49E-06 1.60E-06 8%

Simplot Don-Pocatello P-4 EP-401 Elemental Gaseous Hg 1.80E-05 1.46E-05 -19%

Simplot Don-Pocatello P-4 EP-401 Gaseous Divalent Hg 2.25E-06 2.44E-06 8%

Simplot Don-Pocatello P-4 EP-401 Particulate Divalent Hg 2.25E-06 2.44E-06 8%

Simplot Don-Pocatello P-5 EP-501 Elemental Gaseous Hg 1.27E-04 4.97E-05 -61%

Simplot Don-Pocatello P-5 EP-501 Gaseous Divalent Hg 1.59E-05 -3.22E-05 -303%

Simplot Don-Pocatello P-5 EP-501 Particulate Divalent Hg 1.59E-05 -3.22E-05 -303%

Simplot Rock Springs P-4 EP-40 Elemental Gaseous Hg 5.54E-06 6.98E-06 26%

Simplot Rock Springs P-4 EP-40 Gaseous Divalent Hg 1.59E-06 8.72E-07 -45%

Simplot Rock Springs P-4 EP-40 Particulate Divalent Hg 1.59E-06 8.72E-07 -45%

10.0 ADDITIONAL EMISSIONS TESTING DATA

As described in a separate memorandum1, on January 24, 2014, EPA issued a section 114 

survey and testing request in order to gather additional mercury and hydrogen fluoride emissions 

12
data from calciner operations, and additional hydrogen fluoride emissions data from certain 

WPPA, SPA, and APF lines. 

Hourly emission rates were calculated by multiplying the standardized concentration 

results by the reported volumetric flow rates for each emission point that was tested. The 

corresponding annual hours of production reported by facilities in the section 114 survey were 

then used to estimate the annual emissions for each pollutant and emission point tested. For 

calciner operations, the facility conducted three tests using EPA Method 30B for mercury, and 

two tests using EPA Method 320 for hydrogen fluoride (each test consisting of three consecutive 

one-hour runs). For hydrogen fluoride testing on WPPA, SPA, and APF process lines, facilities

conducted one test using EPA Method 320 consisting of three consecutive one-hour runs. The 

average of the test runs was used to estimate the annual baseline emissions for each emission 

point at each facility. 

As described in a separate memorandum2

, the additional mercury data were used to 

inform the maximum achievable control technology (MACT) floor determinations for mercury 

for phosphate rock calciners in the phosphoric acid manufacturing plants (40 CFR part 63, 

subpart AA) source category. 

The hydrogen fluoride emissions data were used to investigate whether hydrogen fluoride

emission limits could be used as an alternative to the total F emission limits in 40 CFR part 63, 

subpart AA and subpart BB. The EPA is proposing to translate the current total F limit (lbs total 

F/ton P2O5 feed) into the equivalent HF limit (lbs HF/ ton P2O5 feed).

The additional mercury emissions were used to advise an updated risk analysis. The 

multipathway modeling methodology has been updated since the original modeling was 

conducted for this project. Given the new mercury test data that was collected from calciner units 

as part of the 2014 section 114 testing request and the updated modeling methodology, corrected 

calciner mercury emissions were used for multipathway modeling. None of the HF data collected 

in the 2014 ICR testing request were incorporated into the modeling file to re-run the risk 

assessments. This is because all HF emissions from 2014 were less than or similar to the 

emissions from 2010. Therefore, we do not expect any significant impact on the risk assessment 

results nor a change to the proposed rule revisions.

11.0 COMPARISON OF FACILITY EMISSIONS TO MAJOR SOURCE 

THRESHOLDS

When evaluating the facilities that would be included in the analyses conducted for the 

phosphoric acid and phosphate fertilizer RTR, the available emissions data were reviewed. These 

emissions data were reviewed to examine how facility emissions compared to the thresholds for 

major source applicability. Facilities are major sources if a single HAP has emissions greater 

than 10 tons per year, or if total HAP emissions are greater than 25 tons per year. Most 

phosphoric acid and phosphate fertilizer facilities easily exceeded these thresholds. However, 

Mosaic Uncle Sam and Mississippi Phosphates reported in their 2010 section 114 responses that 

they are area sources and thus not subject to NESHAP subpart AA or NESHAP subpart BB. A 

table comparing the available emissions data is provided in Appendix A-9. This table includes 

2005, 2008, and 2011 NEI emissions data along with the estimated emissions from the modeling

file for each facility. Because the HF emissions for Mosaic Uncle Sam and Mississippi 

13
Phosphates show the potential to exceed the 10 tons per year threshold for major sources, we

determined it was appropriate for these facilities to be included in all analyses conducted to 

support the RTR development. Therefore, the available data from all 13 phosphoric acid 

manufacturing and phosphate fertilizer production facilities were used in all analyses conducted. 

12.0 REFERENCES 

1. ERG, 2014. “Information Collection and Additional Data Received for the Phosphoric 

Acid and Phosphate Fertilizer Production Source Categories.” May 2014. 

2. ERG, 2014. “Maximum Achievable Control Technology (MACT) Floor Analysis for 

Phosphate Rock Calciners at Phosphoric Acid Manufacturing Plants.” May 2014.

14