Page 1 of 85

MEMORANDUM

TO: Tina Ndoh, U.S. EPA/OAQPS/SPPD – Minerals and Manufacturing Group

FROM: Eastern Research Group, Inc.

DATE: October 20, 2014

SUBJECT: CAA Section 111(b)(1)(B) and 112(d)(6) Reviews for the Phosphoric Acid 

Manufacturing and Phosphate Fertilizer Production Source Categories

This memorandum summarizes the results of an analysis to identify developments in 

practices, processes, and control technologies that have occurred since the NESHAP and NSPS 

standards were promulgated for the Phosphoric Acid Manufacturing and Phosphate Fertilizer 

Production source categories. This analysis is part of the U.S. Environmental Protection 

Agency’s (EPA) review efforts in accordance with sections 111(b)(1)(B) and 112(d)(6) of the 

Clean Air Act (CAA). This memorandum is organized as follows:

1.0 Background

1.1 Description of the Phosphoric Acid Manufacturing Source Category

1.1.1 Phosphoric Acid Manufacturing NESHAP Requirements

1.1.2 Phosphoric Acid Manufacturing NSPS Requirements

1.2 Description of the Phosphate Fertilizer Production Source Category 

1.2.1 Phosphate Fertilizer Production NESHAP Requirements

1.2.2 Phosphate Fertilizer Production NSPS Requirements

1.3 Facility Overview

2.0 Introduction

3.0 Stack Emissions

3.1 Wet-Process Phosphoric Acid Process Lines

3.2 Superphosphoric Acid Process Lines

3.3 Purified Phosphoric Acid Process Lines

3.4 Phosphate Rock Dryers

3.5 Phosphate Rock Calciners

3.6 Diammonium and/or Monoammonium Phosphate Fertilizer Process Lines

3.7 Triple Superphosphate Lines and Storage Buildings

3.8 Conclusions

4.0 Fugitive Emissions

5.0 References
Page 2 of 85

1.0 BACKGROUND

Section 111 of the CAA requires EPA to establish standards for stationary sources that 

cause or contribute significantly to air pollution which may reasonably be anticipated to 

endanger public health or welfare. These standards must reflect the emission limitation 

achievable through application of the “best system of emission reduction” which the EPA 

determines has been adequately demonstrated. Section 111 also requires the EPA to review these 

standards. Specifically, paragraph 111(b)(1)(B) states: 

(B) ...The Administrator shall, at least every 8 years, review and, if appropriate, revise 

such standards following the procedure required by this subsection for promulgation of 

such standards...

Section 112 of the CAA requires EPA to establish technology-based standards for 

sources of hazardous air pollutants (HAP). These technology-based standards are often referred 

to as maximum achievable control technology, or MACT, standards. Section 112 also contains 

provisions requiring the EPA to periodically revisit these standards. Specifically, paragraph 

112(d)(6) states:

(6) REVIEW AND REVISION. – The Administrator shall review, and revise as 

necessary (taking into account developments in practices, processes, and control 

technologies), emissions standards promulgated under this section no less often than 

every 8 years.

In April 2010, EPA issued a request, pursuant to CAA section 114, to collect information 

from phosphoric acid and phosphate fertilizer manufacturing facilities. Available information

was requested regarding process equipment, control technologies, point and fugitive emissions, 

and other aspects of facility operations. Companies completed the surveys for their facilities and 

submitted the responses to EPA in the fall of 2010. Additionally, EPA requested that the 

facilities conduct emissions tests in 2010 for certain pollutants from specific processes. 

Pollutants tested included hydrogen fluoride (HF), total fluorides (TF), particulate matter (PM),

and most HAP metals. Facilities also conducted analyses of the phosphate rock used in the 

manufacture of phosphoric acid. The results of these tests were submitted to EPA in the fall of 

2010.

On January 24, 2014, EPA issued another section 114 survey and emissions testing 

request to certain facilities in order to gather additional mercury emissions and HF emissions 

from calciner operations, and additional HF emissions from certain wet process phosphoric acid 

(WPPA) lines, superphosphoric acid (SPA) lines, and monoammonium phosphate and 

diammonium phosphate fertilizer (APF) lines. 

For more information regarding the April 2010 section 114 and January 2014 section 114 

requests, please refer to the memorandum entitled “Information Collection and Additional Data 

Received for the Phosphoric Acid and Phosphate Fertilizer Production Source Categories,” 

(ERG, 2014a).
Page 3 of 85

1.1 Description of the Phosphoric Acid Manufacturing Source Category 

The basic step for producing phosphoric acid through the wet phosphoric acid (WPPA) 

process is the acidulation of phosphate rock. Typically, sulfuric acid, phosphate rock, and water 

are reacted together to produce phosphoric acid and gypsum. When phosphate rock is acidulated 

to manufacture WPPA, fluorine contained in the rock is released. Fluoride compounds, including 

HF, are evolved as particulates and gases which are emitted to the atmosphere unless removed 

from the exhaust stream. Some of these same fluoride compounds also remain in the product acid 

and are available for release to the atmosphere during subsequent processing of the acid. 

Gypsum, a by-product of the acidulation reaction, is pumped as a slurry to ponds atop stacks of 

waste gypsum where the liquid separates from the slurry and is decanted for return to the process 

with process cooling water. The gypsum is discarded as a major solid waste stream, and stored in 

large piles that can cover several hundred acres and reach hundreds of feet in height. This 

discarded gypsum is commonly called a,gypstack, or gypsum dewatering stack. WPPA is 

concentrated to make SPA using evaporation.

The federal emission standards that are associated with the Phosphoric Acid 

Manufacturing source category and that were evaluated for this review are:

 National Emission Standards for Hazardous Air Pollutants from Phosphoric Acid 

Manufacturing Plants (40 CFR part 63, subpart AA);

 Standards of Performance for the Phosphate Fertilizer Industry: Wet-Process Phosphoric 

Acid Plants (40 CFR part 60, subpart T); and 

 Standards of Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid 

Plants (40 CFR part 60, subpart U).

1.1.1 Phosphoric Acid Manufacturing NESHAP Requirements

The current National Emissions Standards for Hazardous Air Pollutants (NESHAP) for 

the phosphoric acid manufacturing source category was proposed on December 27, 1996 (61 FR 

68429) and promulgated on June 10, 1999 (64 FR 31358), and codified at 40 CFR part 63, 

subpart AA. As promulgated in 1999, the NESHAP applies to affected sources of HAP 

emissions at phosphoric acid manufacturing plants. The 1999 NESHAP was amended December 

17, 2001 (66 FR 65072), June 12, 2002 (67 FR 40579), June 13, 2002 (67 FR 40817), and April 

20, 2006 (71 FR 20457). The amendments revised the emission limit for calciners and corrected 

an inadvertent error in monitoring requirements. The current NESHAP regulates emissions from 

the following sources at a phosphoric acid manufacturing plant: (1) WPPA process lines 

(including reactors, filters, evaporators, and hot wells), (2) evaporative cooling towers, (3) 

phosphate rock dryers, (4) phosphate rock calciners, (5) SPA process lines (including 

evaporators, hot wells, acid sumps, and cooling tanks), and (6) purified phosphoric acid (PPA)

process lines (including solvent extraction process equipment, solvent stripping and recovery 

equipment, seal tanks, carbon treatment equipment, cooling towers, storage tanks, pumps, and 

process piping). 

The current NESHAP specifies numerical emissions limits for TF for existing WPPA

process lines (0.020 pounds TF per ton of equivalent phosphorus pentoxide (P2O5)); and existing 

vacuum evaporation (0.010 pounds TF per ton of equivalent P2O5) and submerged combustion 
Page 4 of 85

(0.20 pounds TF per ton of equivalent P2O5) processes that are associated with SPA process 

lines. Additionally, emissions limits for PM are specified for existing phosphate rock dryers 

(0.215 pounds PM per ton of equivalent P2O5) and existing rock calciners (0.080 grains per dry 

standard cubic foot). 

The current NESHAP specifies numerical emissions limits for TF for new WPPA process 

lines (0.0135 pounds TF per ton of equivalent P2O5), and new SPA process lines (0.0087 pounds

TF per ton of equivalent P2O5). Additionally, emissions limits for PM are specified for new 

phosphate rock dryers (0.060 pounds PM per ton of equivalent P2O5) and new rock calciners 

(0.040 grains per dry standard cubic foot).

PPA process lines (existing and new sources) are required to comply with the Equipment 

Leak NESHAP (40 CFR 63, subpart H); and are subject to methyl isobutyl ketone (MIBK) 

concentration limitations. Also, the rule does not allow liquid effluent (from any wet scrubbing 

device that is installed to control emissions from process equipment) to be used in evaporative 

cooling towers.

As part of the NESHAP technology review, EPA evaluated HF emissions from emission 

points that have TF emission limits as a surrogate for HF. Data for HF as measured by EPA 

method 26A were received for most emission points. In its previous analysis (see preamble to the 

current NESHAP for phosphoric acid manufacturing at 61 FR 68429), EPA chose to calculate 

MACT floors using TF as a surrogate for HF because the EPA had a large body of existing data 

for the surrogate pollutant TF, and only a limited amount of direct HF emissions data. Also in the 

previous analysis, EPA chose to use PM as a surrogate for the HAP metals. PM is an appropriate 

surrogate for most HAP metals, but is not an adequate surrogate for mercury (Hg) because Hg is 

volatile and not well controlled using emissions control technologies commonly used for other 

HAP metals. In this review, EPA performed a separate evaluation of Hg emissions. 

1.1.2 Phosphoric Acid Manufacturing NSPS Requirements

The EPA promulgated 40 CFR part 60, subpart T for Wet-Process Phosphoric Acid 

Plants on August 6, 1975 (40 FR 33154). The NSPS established standards to control TF

emissions from WPPA plants, including reactors, filters, evaporators, and hot wells. For new 

sources, WPPA plants are limited to 0.020 pounds TF per ton of equivalent P2O5.

The EPA promulgated 40 CFR part 60, subpart U for Superphosphoric Acid Plants on 

August 6, 1975 (40 FR 33155). The NSPS established standards to control TF emissions from 

SPA plants, including evaporators, hot wells, acid sumps, and cooling tanks. For new sources, 

SPA plants are limited to 0.010 pounds TF per ton of equivalent P2O5.

For the NSPS review, EPA evaluated TF emissions from applicable phosphoric acid

manufacturing emission points.

1.2 Description of the Phosphate Fertilizer Production Source Category

Phosphate fertilizers (i.e., diammonium phosphate or monoammonium phosphate, or 

ammonium phosphate fertilizer (APF)) are manufactured by way of three basic steps: reaction 

(where anhydrous ammonia is reacted with phosphoric acid to form diammonium phosphate or 

monoammonium phosphate), granulation (where solidification occurs), and finishing operations 
Page 5 of 85

(where the solid material is dried, cooled, and sent through a screening arrangement for particle 

segregation). Side reactions resulting from the production of APF produce ammonium fluoride, 

ammonium sulfate, and ammonium fluorosilicate. Some of the fluoride contained in the 

phosphate rock is liberated in the process as HF. Another phosphate fertilizer, triple 

superphosphate (TSP), is made as run-of-the-pile-TSP (ROP-TSP) and/or granular TSP (GTSP) 

by reacting phosphoric acid with ground phosphate rock. The phosphoric acid used in the GTSP 

process is appreciably lower in concentration (40 percent P2O5) than that used to manufacture 

ROP-TSP product (50 to 55 percent P2O5). The GTSP process yields larger, more uniform 

particles with improved storage and handling properties than the ROP-TSP process. 

The federal emission standards that are associated with the Phosphate Fertilizer 

Production source category and are subject of this proposed rulemaking are:

 National Emission Standards for Hazardous Air Pollutants from Phosphate Fertilizers 

Production Plants (40 CFR part 63, subpart BB);

 Standards of Performance for the Phosphate Fertilizer Industry: Diammonium Phosphate 

Plants (40 CFR part 60, subpart V);

 Standards of Performance for the Phosphate Fertilizer Industry: Triple Superphosphate 

Plants (40 CFR part 60, subpart W); and

 Standards of Performance for the Phosphate Fertilizer Industry: Granular Triple 

Superphosphate Storage Facilities (40 CFR part 60, subpart X).

1.2.1 Phosphate Fertilizer Production NESHAP Requirements

The current NESHAP for the phosphate fertilizer production source category was 

proposed on December 27, 1996 (61 FR 68429) and promulgated on June 10, 1999 (64 FR 

31358), and codified at 40 CFR part 63, subpart BB. As promulgated in 1999, the NESHAP 

applies to affected sources of HAP emissions at phosphate fertilizer production plants. The 1999

NESHAP was amended December 17, 2001 (66 FR 65072), June 13, 2002 (67 FR 40818), and 

April 20, 2006 (71 FR 20457). The current NESHAP regulates emissions from the following 

sources at a phosphate fertilizer production plant: (1) diammonium and/or monoammonium 

phosphate process lines (including reactors, granulators, dryers, coolers, screens, and mills), (2) 

GTSP process lines (including mixers, curing belts (dens), reactors, granulators, dryers, coolers, 

screens, and mills), and (3) GTSP storage buildings (including storage or curing buildings, 

conveyors, elevators, screens, and mills).

The current NESHAP specifies numerical emissions limits for TF for existing 

diammonium and/or monoammonium phosphate process lines (0.060 pounds TF per ton of 

equivalent P2O5); existing GTSP process lines (0.150 pounds TF per ton of equivalent P2O5); and 

existing GTSP buildings (5.0 x 10-4pounds TF per hour per ton of equivalent P2O5 stored). The 

NESHAP specifies numerical emissions limits for TF for new diammonium and/or 

monoammonium phosphate process lines (0.0580 pounds TF per ton of equivalent P2O5); new 

GTSP process lines (0.123 pounds TF per ton of equivalent P2O5); and new GTSP storage 

buildings (5.0 x 10-4pounds TF per hour per ton of equivalent P2O5 stored). Also, the rule does 

not allow fresh GTSP to be shipped from an affected facility.
Page 6 of 85

For the same reasons as discussed in Section 1.1.1 of this memorandum, EPA evaluated 

HF emissions for the NESHAP technology review for those emission points that have a TF limit 

as a surrogate for HF. 

1.2.2 Phosphate Fertilizer Production NSPS Requirements

The EPA promulgated 40 CFR part 60, subpart V for Diammonium Phosphate Plants on 

July 25, 1977 (42 FR 37938). The NSPS established standards to control TF emissions from 

DAP plants, including reactors, granulators, dryers, coolers, screens, and mills. For new sources, 

DAP plants are limited to 0.06 pounds TF per ton of equivalent P2O5 feed.

The EPA promulgated 40 CFR part 60, subpart W for Triple Superphosphate Plants on 

July 25, 1977 (42 FR 37938). The NSPS established standards to control TF emissions from the 

production of ROP-TSP and GTSP, and the storage of ROP-TSP. For new sources, production of 

ROP-TSP and GTSP and the storage of ROP-TSP is limited to 0.20 pounds TF per ton of 

equivalent P2O5 feed.

The EPA promulgated 40 CFR part 60, subpart X for Granular Triple Superphosphate 

Storage Facilities on July 25, 1977 (42 FR 37938). The NSPS established standards to control 

total fluoride emissions from the storage of GTSP, including storage or curing buildings (noted 

as “piles” in subpart X), conveyors, elevators, screens and mills. For new sources, the storage of 

GTSP is limited to 5.0x10-4pounds of TF per hour per ton of equivalent P2O5 stored.

For the NSPS review, EPA evaluated TF emissions from applicable phosphate fertilizer 

production emission points.

1.3 Facility Overview

Today, there are 12 phosphoric acid manufacturing facilities and 10 of the 12 facilities 

also produce phosphate fertilizers. One additional facility only produces phosphate fertilizers. In 

total there are 13 facilities subject to the NESHAP and NSPS rules. We are not aware of any 

facility currently under construction, or in the process of expanding their operations. Appendix A 

provides a list of facilities located in the United States that are considered to be part of the 

phosphoric acid manufacturing and/or phosphate fertilizer production source category. Note, 

there are no facilities that currently operate a GTSP process line, although one facility retains a 

permit to store GTSP.1

2.0 INTRODUCTION

We investigated developments in practices, processes, and control technologies at 

phosphoric acid manufacturing plants and phosphate fertilizer production plants for stack 

emissions of TF, HF, Hg, total metal HAP (excluding Hg and Phosphorous (P)), and PM. This 

review also considered both (1) whether developments in technology or other factors support the 

conclusion that a different system of emissions reduction has become the “best system of 

emissions reduction” and (2) whether emissions limitations and percent reductions beyond those 

required by the standards are achieved in practice.

 

1 The PCS Phosphate Company, Inc., located in Aurora, NC.
Page 7 of 85

For the purposes of this review, we considered any of the following to be a 

“development”:

 Any add-on control technology or other equipment that was not identified and 

considered during development of the original NESHAP and NSPS standards.

 Any improvements in add-on control technology or other equipment (that were 

identified and considered during development of the original NESHAP and NSPS 

standards) that could result in additional emissions reduction. 

 Any work practice or operational procedure that was not identified or considered 

during development of the original NESHAP and NSPS standards. 

 Any process change or pollution prevention alternative that could be broadly applied 

to the industry and that was not identified or considered during development of the 

original NESHAP and NSPS standards.

 Any significant changes in the cost (including cost effectiveness) of applying controls 

(including controls the EPA considered during the development of the original 

NESHAP and NSPS standards).

To identify developments, we examined the data EPA received in response to the section 

114 request from the 13 operating facilities. These data included descriptions of processes and 

detailed information on all control technologies in the source category. Stack test data were also 

collected in response to the section 114 request for TF, HF, PM, and the metal HAP compounds. 

The stack test data was gathered in response to a section 114 request specifically for 

NESHAP development and review. However, this same data were also used when conducting 

the NSPS review because the NESHAP and NSPS rules cover the same sources. We established 

this overlap by comparing the regulatory requirements between the related NSPS and NESHAP 

regulations:

 NSPS subpart T covers the same emission sources at WPPA plants and control the 

same pollutants as NESHAP subpart AA (ERG, 2014d);

 NSPS subpart U covers the same emission sources at SPA plants and control the same 

pollutants as NESHAP subpart AA (ERG, 2014e);

 NSPS subpart V covers the same emission sources at DAP plants and control the 

same pollutants as NESHAP subpart BB (ERG, 2014f);

 With the exception of ROP-TSP which is no longer being produced in North America

(see Section 3.7 of this memorandum), NSPS subparts W and X cover the same 

emission sources at TSP plants and control the same pollutants as NESHAP subpart 

BB (ERG, 2014g). 
Page 8 of 85

Because the NESHAP and NSPS rules cover the same emission sources, the data 

gathered as part of the NESHAP development and technology review is also applicable for the 

NSPS review. 

We also conducted searches of EPA’s RACT/BACT/LAER (Reasonably Achievable 

Control Technology/Best Available Control Technology/Lowest Achievable Emissions Rate) 

(U.S. EPA, 2012) clearinghouse and the Internet for information on phosphoric acid 

manufacturing and phosphate fertilizer production processes, reviewed technologies employed 

by similar industries, and reviewed new or updated NESHAPs for other source categories. 

However, the majority of the information considered for this technology review was submitted in 

response to the section 114 data request. The results of these analyses are presented in the 

following sections.

3.0 STACK EMISSIONS

Based on a search of EPA’s RACT/BACT/LAER database, we have found no new 

developments in practices, processes, and control technologies for phosphoric acid 

manufacturing and phosphate fertilizer production plants.

Wet scrubbing is the primary control technology used across the industry for control of 

TF and HF emissions. However, we examined the stack emissions data provided by industry for

outliers. The primary purpose of this exercise was to determine whether outlier emissions data 

associated with specific stack emission points were related to a control technology (when 

compared to all other emission points). We could not directly calculate control efficiencies due 

to lack of inlet concentration data; however, we compared the outlet TF, HF, total metal 

(excluding Hg and P), Hg, and PM concentrations from the different control technologies based 

on emissions data that EPA received in response to the section 114 data request. In addition, we 

compared normalized emissions. We normalized the concentration data to a production basis

(pounds emitted per thousand tons of P2O5) using each facility’s P2O5 production rate2reported 

during the stack test. Emissions of P were excluded from the total metal HAP emissions analyses 

discussed in this memo because we do not believe the reported P emissions are in the form of the 

HAP white P, but rather in the form of a phosphate which is not a HAP metal. Because we were 

unable to speciate the reported P emissions into HAP P emissions and other non-HAP P 

compound emissions, we did not compare different control technologies based on P emissions 

data that EPA received in response to the section 114 request.

To facilitate this exercise, we created concentration and normalized emission bar charts 

using the stack emissions data provided by industry in response to the section 114 request. 

Appendix B contains bar charts for emission points associated with WPPA process lines. 

Appendix C contains bar charts for emission points associated with SPA process lines. Appendix 

D contains bar charts for emission points associated with APF process lines. We were unable to 

determine outlier stack emissions data associated with PPA process lines, phosphate rock dryers, 

and phosphate rock calciners because EPA only received stack emissions data for these 

operations from one facility. There are no facilities that operate a GTSP process line or storage 

building; therefore, we did not receive and/or analyze stack emissions data for these operations.

 

2 The standard practice in the fertilizer industry is to use the oxide form, i.e., P2O5, to express the available 

phosphate content of the fertilizers made.
Page 9 of 85

Phosphoric acid manufacturing plants and phosphate fertilizer production plants may use 

multiple control technologies to comply with current standards. However, based on a review of 

the section 114 responses, the most common final control technology (i.e., the control 

technology directly prior to the exit stack) used by these facilities is wet scrubbing (no matter 

whether the emission point is associated with a WPPA, APF, SPA, or PPA process). PM and 

acid gases (from waste gas streams of stationary point sources) are removed primarily during wet 

scrubbing through impaction, diffusion, interception and/or absorption of the pollutant onto 

droplets of liquid (U.S. EPA, 2002). The liquid containing the pollutant is then collected for 

disposal. 

There are numerous types of wet scrubbers which remove both acid gas and PM (e.g., 

venturi, impingement, crossflow, or packed bed wet scrubbers). We examined outlier emissions 

data to compare whether one control technology used by phosphate facilities is more or less 

effective than another (and /or whether any anomalies exist between measured emissions and a 

certain type of control technology). Sections 3.1 through 3.7 provide a summary of the various 

control technology used at stack emission points. When possible, we also discuss in these 

sections our observations and conclusions regarding outlier emission data associated with 

fluoride (TF and HF), total metal (excluding Hg and P), Hg, and PM emissions. Section 3.8

provides an overall summary of our conclusions in regards to this analysis (for stack related 

processes).

The outlier emissions analysis was initially conducted using only stack test data from the 

2010 section 114 request. The subsequent section 114 request in 2014 gathered additional HF

and Hg data for a subset of the emission points. Data were only provided for about 14% of the 

total emission points in phosphoric acid or phosphate fertilizer plants, so a comprehensive data 

review was not possible. However, the HF data from 2014 and 2010 were compared to determine 

if using the 2010 HF data were still appropriate or if the 2014 HF data would provide a different 

conclusion. See Appendix F for a comparison of the data. Most of the 2014 HF test data were 

lower than the 2010 HF data, and would therefore not affect the results of the technology review. 

However, HF emissions data for EP-541 at Agrium Nu-West’s SPA process line was 

significantly different between 2010 and 2014, which we believe to be partially due to this 

source being uncontrolled. Therefore, the 2014 HF emissions test data has been incorporated into 

the SPA process line discussion (see section 3.2.2 of this technology review memorandum).

In addition to reviewing the control technology which each facility uses to control 

emissions, we analyzed the elemental composition analyses of phosphate rock collected by each 

facility in response to the section 114 request. We performed this analysis because emissions are 

derived from the metals and fluoride content of the mined phosphate rock. Facilities were 

required to analyze their rock (i.e., phosphate rock ore and beneficiated phosphate rock) for the 

content of certain metals and fluorides. We determined no distinguishable correlation between 

the results of the rock analyses and the emissions test data. Those facilities with high metals or 

fluoride content in their phosphate rock did not necessarily exhibit high concentrations or high

normalized emission rates from their stack test. Similarly, facilities with low metals or fluoride 

content in their phosphate rock did not necessarily have low concentrations or low normalized 

emission rates. These observations are illustrated in the figures presented in Appendix E. Due to 

the fact that no correlation was observed, a facility’s phosphate rock source was not considered 
Page 10 of 85

when performing the technology review to help explain why a particular facility had high or low

concentrations or high or low normalized emission rates.

3.1 Wet-Process Phosphoric Acid Process Lines

A WPPA process line typically consists of a reaction and digestion step (where phosphate 

rock is acidulated with sulfuric acid to form phosphoric acid), a filtration step (where solids are 

separated from the acid to produce about a 30 percent concentrated phosphoric acid), and an 

evaporation step (where the concentration of phosphoric acid is increased to about 54 percent). 

These process steps are controlled by wet scrubbing. However, the quantity and configuration of 

reactors/digesters, filters, and evaporators, as well as the type and configuration of the wet 

scrubbing technology used to control these processes, vary significantly between each facility. 

Because of the inconsistencies in the arrangement of the equipment exhausting to the wet 

scrubbers at WPPA process lines, it was difficult to determine whether outlier emissions data 

associated with each WPPA process line were related to a control technology (when compared to 

all other WPPA process lines). 

EPA received emissions data for 19 different emission points in WPPA process lines. We 

analyzed the arrangement of equipment that exhausts through each of these emission points. We 

determined that in order to evaluate against existing emissions limits, obtain a complete 

representation of total emissions associated with an individual WPPA process line, and to 

perform consistent comparisons between individual process lines, we needed to group some 

emission points (either by summing emissions from the various emission points that the facility 

tested, and/or supplementing representative emissions data for emission points that were not 

tested, but still associated with a facility’s WPPA process line). The specific treatment of these 

emission points are discussed below (if a facility that reported emissions is not discussed below, 

we determined that the facility reported total WPPA process line emissions data in such a way 

that no grouping was necessary). This methodology for consolidating emission points into 

individual process lines is consistent with the method of compliance for the current rule. 

The Mosaic New Wales facility reported emissions from the following two emission 

points: an emission point that is associated with only one of three reactor/filter trains located at 

the facility (EP-11); and an emission point that is associated with all three reactor/filter trains 

located at the facility (EP-22 which captures emissions from clarifiers and tanks). The facility 

did not report emissions from EP-12 (which is also considered a primary emission point for the 

WPPA process line); the emission point was not tested because the facility stated that EP-12 has 

similar emissions to EP-22. In order to account for all emissions associated with only one WPPA 

process line at the Mosaic New Wales facility, we adjusted the reported emissions from emission 

point EP-22 downward by the ratio of P2O5 feed through each of the three reactor/filter trains. 

We used EP-22 as representative emissions data for EP-12, and then combined EP-11, EP-12, 

and EP-22.

To account for all emissions associated with Agrium Nu-West’s WPPA process line, we 

combined the emissions from the four emission points reported (EP-283; EP-3241; EP-71; and 

EP-6101). Emissions from EP-3241 were tripled to account for emissions from two similar 

emission points not reported by the facility.
Page 11 of 85

The PCS White Springs facility provided emissions data for three emission points (EP69.01; EP-20.01; and EP-20.02) which encompass two WPPA process lines. We combined the 

emissions from emissions points EP-20.01 and EP-20.02 because these emission points are 

associated with the same WPPA process line. 

The PCS Aurora facility provided emissions data for four emission points (EP-403; EP404; EP-408; and EP-409) which encompass two WPPA process lines. We combined the 

emissions from emissions points EP-403 and EP-404 because these emission points are 

associated with the same WPPA process line. We also combined the emissions from emissions 

points EP-408 and EP-409 because these emission points are associated with the other WPPA 

process line. Emissions from emission points EP-404 and EP-409 were doubled to account for 

emissions from similar emission points not reported by the facility.

The Mosaic Uncle Sam facility is configured to produce high concentration phosphoric 

acid via evaporators; however, the reported emissions (EP-01) do not represent emissions from 

that portion of equipment. Therefore, EP-01 may not be comparable to other WPPA process lines 

examined because EP-01 only represents emissions from the reaction and filtration steps. We 

included this emission point in our analysis. As expected, emissions from this emission point (for 

each pollutant) were low compared to the emissions associated with other WPPA process lines 

(because all other WPPA process lines reported emissions that include high concentration 

phosphoric acid equipment).

The following subsections of this memorandum discuss the emissions from specific

WPPA emission points considered to be outlier emissions data. For the purposes of this analysis, 

we considered emissions data an outlier if the emissions were located in the upper 33 percent of 

the full range of available data (the range was determined by plotting all available emission 

points for a specific pollutant using a uniform, even spread that was based on the lowest and 

highest emissions for that specific pollutant). These outlier emissions data may be more easily 

identified by referencing the charts provided in Appendix B.

3.1.1 Total Fluoride Emission Outliers for Wet Process Phosphoric Acid Emission Points 

Reported

Direct measurements of TF concentration were provided for 11 of the 12 WPPA emission 

points we examined. Table 3.1 shows TF emissions from specific stack emission points with 

outlier emissions data highlighted in red.

Table 3.1: Total Fluoride Emissions from Wet Process Phosphoric Acid Emission Points

Facility EP ID

Total Fluoride

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West Combined 1.25E-03 14.4

CFI Plant City EP-stack 1.20E-03 2.95

Mosaic New Wales Combined 4.11E-03 17.1

PCS Aurora Combined 8.76E-04 10.8

PCS Aurora Combined 7.69E-04 6.52
Page 12 of 85

Facility EP ID

Total Fluoride

(gr/dscf) (lbs/thousand 

tons of P2O5)

PCS White Springs EP-69.01 8.49E-04 3.25

Simplot Don-Pocatello EP-501 1.92E-04 1.08

Mosaic Uncle Sam EP-01 7.74E-05 0.54

PCS White Springs Combined 5.00E-04 6.77

PCS Geismar EP-5 2.05E-05 0.11

Mississippi Phosphates EP-1 NAaNAa

Simplot Rock Springs EP-50 1.47E-04 0.17

a) Total Fluoride analysis for this emission point was not available

The Mosaic New Wales combined emission point (EP-11 and EP-22) emits about seven 

times the TF concentration compared to the average of the rest of the population of TF 

concentration data. When normalized to total F emissions (pounds TF per thousand tons P2O5), 

the Mosaic New Wales combined emission point (EP-11 and EP-22), the Agrium Nu-West 

combined emission point (EP-283; EP-3241; EP-71; and EP-6101), and the PCS Aurora 

combined emission point (EP 401 and EP 404) are each at least four times higher than the 

average of the rest of the population of data. These emissions are still below the current 

NESHAP emission limit of 0.020 pounds TF per ton P2O5.

The outlier TF emissions data may be related to the control technology being used; 

however, it is difficult to discern because each WPPA process line operates a unique equipment 

and control technology configuration (i.e., there are no WPPA process lines that operate similar 

configurations to compare). The three primary emission points associated with Mosaic New 

Wales’s WPPA process line are each controlled by a wet scrubber (EP-11 uses crossflow 

technology to control a reactor, filter, and evaporators; EP-12 uses packed bed technology to 

control tanks and clarifiers; and EP-22 uses packed bed technology to control tanks and 

clarifiers, as well as an extra filtration step). Three of the four primary emission points associated 

with Agrium Nu-West’s WPPA process line are each controlled by a wet scrubber (EP-71 uses 

crossflow technology to control a reactor, filter, evaporator, tanks and clarifiers; EP-6101 uses 

packed bed technology to control an evaporator and tanks; EP-3241 uses an unknown scrubbing 

technology to control a filtration step; and EP-283 is an uncontrolled barometric condenser).

Both emissions points for PCS Aurora are also controlled by wet scrubbers (EP-401 uses a 

cyclone scrubber to control filters and tanks; EP-404 uses a cyclone scrubber to control reactor, 

filter, hot well, barometric condenser, and tank emissions).

3.1.2 Hydrogen Fluoride Emission Outliers for Wet Process Phosphoric Acid Emission 

Points Reported

Direct HF concentration measurements were provided for 11 of the 12 WPPA emission 

points we examined. Table 3.2 shows HF emissions from specific stack emission points with 

outlier emissions data highlighted in red.
Page 13 of 85

Table 3.2: Hydrogen Fluoride Emissions from Wet Process Phosphoric Acid Emission Points

Facility EP ID

Hydrogen Fluoride

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West Combined 3.60E-04 3.82

CFI Plant City EP-stack NAaNAa

Mosaic New Wales Combined 3.58E-03 11.5

PCS Aurora Combined 1.42E-03 12.8

PCS Aurora Combined 1.27E-03 7.65

PCS White Springs EP-69.01 1.46E-03 5.35

Simplot Don-Pocatello EP-501 1.71E-04 1.06

Mosaic Uncle Sam EP-01 2.67E-05 1.91E-01

PCS White Springs Combined 1.05E-03 14.2

PCS Geismar EP-5 1.55E-03 13.5

Mississippi Phosphates EP-1 3.14E-03 9.79

Simplot Rock Springs EP-50 1.31E-04 1.50E-01

a) HF data for this emission point was not available

The Mosaic New Wales combined emission point (EP-11 and EP-22) and the Mississippi 

Phosphates emission point EP-1 each emit about four times the HF concentration compared to 

the average of the rest of the population of HF concentration data. When normalized to HF 

emissions (pounds HF per thousand tons P2O5), the Mosaic New Wales combined emission point 

(EP-11 and EP-22), the PCS Aurora combined emission point (EP 401 and EP 404), the PCS 

White Springs combined emission point (EP-20.01 and EP-20.02), and the PCS Geismar 

emission point EP-5 are each at least three times higher than the average of the rest of the 

population of data.

The outlier HF emissions data may be related to the control technology being used; 

however, it is difficult to discern because each WPPA process line operates a unique equipment 

and control technology configuration (i.e., there are no WPPA process lines that operate similar 

configurations to compare). The three primary emission points associated with Mosaic New 

Wales’s WPPA process line are each controlled by a wet scrubber (EP-11 uses crossflow 

technology to control a reactor, filter, and evaporators; EP-12 uses packed bed technology to 

control tanks and clarifiers; and EP-22 uses packed bed technology to control tanks and 

clarifiers, as well as an extra filtration step). Both emissions points for PCS Aurora are controlled 

by wet scrubbers (EP-401 uses a cyclone scrubber to control filters and tanks; EP-404 uses a 

cyclone scrubber to control reactor, filter, hot well, barometric condenser, and tank emissions).

The two primary emission points associated with PCS White Springs’s WPPA process line are 

each controlled by a wet scrubber (EP-20.01 uses packed bed technology to control reactors, 

filters, evaporators, and tanks; and EP-20.02 uses packed bed technology to control filters, 

evaporators, and tanks). The WPPA process line at the PCS Geismar facility uses seven wet

scrubbers of unknown scrubbing technology to control reactors, filters, evaporators, and tanks. 

The equipment configuration associated with the WPPA process line at the Mississippi 

Phosphates facility is considered confidential.
Page 14 of 85

3.1.3 Total Metals Emission Outliers for Wet Process Phosphoric Acid Emission Points 

Reported

The total metals analysis discussion is based on a review of all the metals data (excluding 

Hg and P) even if non-detect data were present (i.e., metal emission concentrations reported as 

below detection limit or detection level limited were included in the total emissions reported). 

Direct measurements of total metals concentration were provided for all 12 WPPA emission 

points we examined. Table 3.3 shows total metals emissions from specific stack emission points 

with outlier emissions data highlighted in red. It should be noted that even though we have 

identified outlier emissions data, the outlier total metals emissions are very low (i.e., the total 

sum of all total metals emissions reported at WPPA process lines, including outliers, is about 550 

pounds of total metals per year); this analysis was only performed to discern if the outliers are 

related to a control technology (when compared to all other emission points).

Table 3.3: Total Metals Emissions from Wet Process Phosphoric Acid Emission Points

Facility EP ID

Total Metals

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West Combined 5.51E-06 6.10E-02

CFI Plant City EP-stack 8.42E-06 2.28E-02

Mosaic New Wales Combined 1.10E-05 3.57E-02

PCS Aurora Combined 2.82E-06 2.48E-02

PCS Aurora Combined 3.72E-06 3.16E-02

PCS White Springs EP-69.01 6.42E-06 2.46E-02

Simplot Don-Pocatello EP-501 6.70E-06 3.96E-02

Mosaic Uncle Sam EP-01 1.29E-06 9.08E-03

PCS White Springs Combined 7.60E-06 9.81E-02

PCS Geismar EP-5 1.15E-05 9.67E-02

Mississippi Phosphates EP-1 2.88E-05 8.49E-02

Simplot Rock Springs EP-50 2.77E-06 3.18E-03

The Mississippi Phosphates combined emission point EP-1 emits about four and one-half

times higher total metals concentration compared to the average of the rest of the entire 

population of total metals concentration data. When normalized to total metals emissions 

(pounds metals per thousand tons P2O5), the Mississippi Phosphates emission point EP-1, the 

PCS White Springs combined emission points (EP-20.01 and EP-20.02), and the PCS Geismar 

emission point EP-5 are each at least three times higher than the average of the rest of the 

population of data.

The outlier total metals emissions data may be related to the control technology being 

used; however, it is difficult to discern because each WPPA process line operates a unique

equipment and control technology configuration (i.e., there are no WPPA process lines that 

operate similar configurations to compare). The two primary emission points associated with 

PCS White Springs’s WPPA process line are each controlled by a wet scrubber (EP-20.01 uses 

packed bed technology to control reactors, filters, evaporators, and tanks; and EP-20.02 uses 
Page 15 of 85

packed bed technology to control filters, evaporators, and tanks). The WPPA process line at the 

PCS Geismar facility uses seven wet scrubbers of unknown scrubbing technology to control 

reactors, filters, evaporators, and tanks. The equipment configuration associated with the WPPA 

process line at the Mississippi Phosphates facility is considered confidential.

3.1.4 Mercury Emission Outliers for Wet Process Phosphoric Acid Emission Points 

Reported

Direct measurements of Hg concentration (using EPA Method 30B) were provided for 

nine of the 12 WPPA emission points we examined. Direct measurements of Hg concentration 

using the Ontario-Hydro Method were also provided by facilities, but we used the measurements 

associated with Method 30B because the method typically results in better detection limits. Table 

3.4 shows Hg emissions from specific stack emission points with outlier emissions data 

highlighted in red. It should be noted that even though we have identified outlier emissions data, 

the outlier Hg emissions are very low (i.e., the total sum of all Hg emissions reported at WPPA 

process lines, including outliers, is about 4.0 pounds of Hg per year); this analysis was only 

performed to see if the outliers are related to a control technology (when compared to all other 

emission points).

Table 3.4: Mercury Emissions from Wet Process Phosphoric Acid Emission Points

Facility EP ID

Mercury

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West Combined 4.42E-08 4.63E-04

CFI Plant City EP-stack 7.53E-08 1.83E-04

Mosaic New Wales Combined NA NA

PCS Aurora Combined 1.63E-08 1.36E-04

PCS Aurora Combined 3.59E-08 2.48E-04

PCS White Springs EP-69.01 1.65E-07 6.39E-04

Simplot Don-Pocatello EP-501 7.74E-08 4.72E-04

Mosaic Uncle Sam EP-01 NA NA

PCS White Springs Combined 3.99E-08 5.07E-04

PCS Geismar EP-5 NA NA

Mississippi Phosphates EP-1 1.35E-07 4.16E-04

Simplot Rock Springs EP-50 1.57E-08 1.80E-05

The PCS White Springs emission point (EP-69.01) and Mississippi Phosphates combined 

emission point EP-1 each emit about three to four times higher Hg concentration compared to the 

average of the rest of the entire population of total Hg concentration data. When normalized to 

Hg emissions (pounds Hg per thousand tons P2O5), the Agrium Nu-West combined emission 

point (EP-283; EP-3241; EP-71; and EP-6101), and the PCS White Springs emission point (EP69.01) and combined emission point (EP-20.01 and EP-20.02) are each about two to three times 

higher than the average of the rest of the population of data.
Page 16 of 85

The outlier total Hg emissions data may be related to the control technology being used; 

however, it is difficult to discern because each WPPA process line operates a unique equipment 

and control technology configuration (i.e., there are no WPPA process lines that operate similar 

configurations to compare). Three of the four primary emission points associated with Agrium 

Nu-West’s WPPA process line are each controlled by a wet scrubber (EP-71 uses crossflow 

technology to control a reactor, filter, evaporator, tanks and clarifiers; EP-6101 uses packed bed 

technology to control an evaporator and tanks; EP-3241 uses an unknown scrubbing technology 

to control a filtration step; and EP-283 is an uncontrolled barometric condenser). The equipment 

associated with PCS White Springs’s emission point EP-69.01 is configured with a wet scrubber 

that uses crossflow technology to control a reactor, filter, and tanks. The equipment associated 

with PCS White Springs’s emission points EP-20.01 and EP-20.02 are each controlled by a wet 

scrubber (EP-20.01 uses packed bed technology to control reactors, filters, evaporators, and 

tanks; and EP-20.02 uses packed bed technology to control filters, evaporators, and tanks). The

equipment configuration associated with the WPPA process line at the Mississippi Phosphates 

facility is considered confidential.

3.1.5 PM Emission Outliers for PA Emission Points Reported

Direct measurements of PM concentrations were provided for 10 of 12 PA emission 

points we examined. Table 3.5 shows PM emissions from specific stack emission points with 

outlier emissions data highlighted in red.

Table 3.5: Particulate Matter Emissions from Phosphoric Acid Emission Points

Facility EP ID

Particulate Matter

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West Combined 4.90E-04 4.55

CFI Plant City EP-stack NA NA 

Mosaic New Wales Combined 9.80E-03 32.2

PCS Aurora Combined 2.93E-03 25.77

PCS Aurora Combined 2.46E-03 17.4

PCS White Springs EP-69.01 5.32E-03 19.5

Simplot Don-Pocatello EP-501 4.03E-03 22.5

Mosaic Uncle Sam EP-01 2.56E-03 19.0

PCS White Springs Combined 3.18E-03 38.3

PCS Geismar EP-5 3.08E-03 27.2

Mississippi Phosphates EP-1 NA NA 

Simplot Rock Springs EP-50 1.48E-03 1.92

The Mosaic New Wales combined emission point (EP-11 and EP-22) emits about three 

and one-half times higher PM concentration compared to the average of the rest of the entire 

population of PM concentration data. When normalized to PM emissions (pounds particulate per 

thousand tons P2O5), the PCS White Springs combined emission point (EP-20.01 and EP-20.02) 

is about two times higher than the average of the rest of the population of data.
Page 17 of 85

The outlier PM emissions data may be related to the control technology being used; 

however, it is difficult to discern because each WPPA process line operates a unique equipment 

and control technology configuration (i.e., there are no WPPA process lines that operate similar 

configurations to compare). The three primary emission points associated with Mosaic New 

Wales’s WPPA process line are each controlled by a wet scrubber (EP-11 uses crossflow 

technology to control a reactor, filter, and evaporators; EP-12 uses packed bed technology to 

control tanks and clarifiers; and EP-22 uses packed bed technology to control tanks and 

clarifiers, as well as an extra filtration step). The two primary emission points associated with 

PCS White Springs’s WPPA process line are each controlled by a wet scrubber (EP-20.01 uses 

packed bed technology to control reactors, filters, evaporators, and tanks; and EP-20.02 uses 

packed bed technology to control filters, evaporators, and tanks).

3.2 Superphosphoric Acid Process Lines

In general, there is a consistent arrangement of equipment which exhausts to control

technologies at SPA process lines. Most often a SPA process line consists of nothing more than 

additional evaporation steps immediately following a WPPA process line; the additional 

evaporation steps increase the concentration of the phosphoric acid to about 70 percent. 

However, some SPA process lines may also include an oxidation step to remove organic 

impurities from the acid (not every facility has a need to remove organic impurities, and one 

facility calcines their feed rock prior to processing and uses an oxidation step after processing 

due to the high organic content of the phosphate ore). 

For all SPA process lines that we examined, emissions from the evaporators are sent to a 

single wet scrubber. The type of wet scrubbing system varied between each SPA emission point 

(i.e., venturi, crossflow, packed bed, or other wet scrubber type). We analyzed whether outlier 

emissions data associated with each SPA process line were related to a control technology (when 

compared to all other SPA process lines). 

EPA received emissions data for seven different emission points in SPA process lines. 

However, we analyzed the arrangement of equipment that exhausts through each of these 

emission points and determined that it was necessary to combine the Agrium Nu-West emissions 

points EP-541 and EP-522 (i.e., by summing the reported emissions) in order to obtain a 

complete representation of total emissions associated with the individual SPA process line that 

includes an oxidation reactor. After combining the emission points, we could compare the 

emissions to another facility (Simplot Don-Pocatello) that also operates an oxidation reactor as 

part of their SPA process line as indicated in the facility’s Title V permit. This methodology for 

consolidating emission points into individual process lines is consistent with the method of 

compliance for the rule.

The following subsections of this report discuss the emissions from specific SPA

emission points considered to be outlier emissions data. For purposes of this analysis, we 

considered emissions data an outlier if the emissions were located in the upper 33 percent of the 

full range of available data (the range was determined by plotting all available emission points 

for a specific pollutant using a uniform, even spread that was based on the lowest and highest 

emissions for that specific pollutant). These outlier emissions data may be more easily identified 

by referencing the charts provided in Appendix C.
Page 18 of 85

3.2.1 Total Fluoride Emission Outliers for Superphosphoric Acid Emission Points Reported

Direct TF concentration measurements were provided for all six SPA emission points we 

examined. Table 3.6 shows total F emissions from specific stack emission points with outlier 

emissions data highlighted in red.

Table 3.6: Total Fluoride Emissions from Superphosphoric Acid Emission Points

Facility EP ID Control Technology

Total Fluorides

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West1,2 Combined Crossflow Scrubber 4.45E-03 6.84

Simplot Don-Pocatello1,3 EP-401 Packed Bed Scrubber 4.53E-04 4.76E-01

PCS White Springs EP-70.01 Other Scrubber Type 1.62E-03 7.63

PCS Aurora EP-331 Venturi Scrubber 3.34E-04 1.39E-01

PCS Aurora EP-332 Venturi Scrubber 6.13E-04 2.36E-01

Simplot Rock Springs EP-40 Venturi Scrubber 7.69E-04 1.38

Notes:

1. Emissions from the oxidation reactor process are included.

2. Emissions from the oxidation reactor process are uncontrolled.

3. Emissions from the oxidation reactor process are controlled.

The Agrium Nu-West combined emission point (EP-522 and EP-541) emits about six 

times the TF concentration compared to the average of the rest of the population of TF

concentration data. When normalized to TF emissions (pounds TF per thousand tons P2O5), the 

Agrium Nu-West combined emission point (EP-522 and EP-541) and the PCS White Springs 

emission point EP-70.01 are each at least 12 times higher than the average of the rest of the 

population of data. These emissions are still below the current NESHAP emission limit of 0.010

pounds TF per ton P2O5.

We determined that the uncontrolled oxidation process associated with the Agrium NuWest SPA process line only contributes a small percentage to the observed high TF emissions. If 

the emissions associated with just the oxidation process were removed from the analysis, the TF

emissions (pounds TF per thousand tons P2O5) from the Agrium Nu-West SPA process line, 

would still be at least 10 times higher than the average emissions of the rest of the population 

(excluding the PCS White Springs emission point EP-70.01). This outlier TF emissions data may 

be related to the crossflow scrubbing technology being used; however, it is difficult to be certain 

because there are no other emission points that operate a similar scrubber to compare. We are 

unable to conclude whether control technology plays a role on the PCS White Spring outlier TF

emissions data point because we do not know the type of scrubber being used to control this 

specific SPA process line.

3.2.2 HF Emission Outliers for SPA Emission Points Reported

Direct measurements of HF concentration were provided for the six SPA emission points 

we examined. HF emissions data from both the 2010 section 114 testing and 2014 section 114 

testing are included in the HF outlier analysis for Agrium Nu-West. Table 3.7 shows HF 

emissions from specific stack emission points with outlier emissions data highlighted in red.
Page 19 of 85

Table 3.7: Hydrogen Fluoride Emissions from Superphosphoric Acid Emission Points

Facility EP ID Control Device

Hydrogen Fluoride

Test Year (gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West1,2 Combined Crossflow Scrubber 2010 6.80E-03 9.9

Agrium Nu-West1,2 Combined Crossflow Scrubber 2014 1.41E-01 19.7

Simplot Don-Pocatello1,3 EP-401 Packed Bed Scrubber 2010 8.58E-04 6.73E-01

PCS White Springs EP-70.01 Other Scrubber Type 2010 7.59E-04 3.56

PCS Aurora EP-331 Venturi Scrubber 2010 5.66E-04 3.80E-01

PCS Aurora EP-332 Venturi Scrubber 2010 2.00E-03 1.24E+00

Simplot Rock Springs EP-40 Venturi Scrubber 2010 5.95E-04 1.27

Simplot Rock Springs EP-40 Venturi Scrubber 2014 1.08E-03 4.52

Notes:

1. Emissions from the oxidation reactor process are included.

2. Emissions from the oxidation reactor process are uncontrolled.

3. Emissions from the oxidation reactor process are controlled.

The Agrium Nu-West combined emission point (EP-522 and EP-541) emits about seven 

times (referring to 2010 Agrium Nu-West test data) or 144 times (referring to 2014 Agrium NuWest test data) the HF concentration compared to the average of the rest of the population of HF 

concentration data. When normalized to HF emissions (pounds HF per thousand tons P2O5), the 

same emission point is about five times (referring to 2010 Agrium Nu-West test data) or ten

times (referring to 2014 Agrium Nu-West test data) higher than the average of the rest of the 

population of data.

We determined that the uncontrolled oxidation process (EP-541) associated with the 

Agrium Nu-West SPA process line may contribute a significant percentage to the observed high 

HF emissions. While the oxidation process contributed only four percent of the HF emissions 

based on the 2010 test data, the oxidation process contributed 81 percent of the SPA process line 

emissions based on 2014 test data. This 2014 HF data exceed the proposed HF limit for SPA 

process lines in subpart AA. The lack of control technology for the oxidation process is a main

factor when examining the emissions data. If this emission point were controlled by a wet 

scrubber, the Agrium Nu-West SPA process line 2014 HF data would not be considered an 

outlier nor exceed the proposed HF limit. In addition, the use of wet scrubbing technology would

be consistent with other SPA process lines, where all applicable emission points are controlled 

by wet scrubbers.

3.2.3 Total Metals Emission Outliers for Superphosphoric Acid Emission Points Reported

The total metals analysis discussion is based on a review of all the metals data (excluding 

Hg and P) even if non-detect data were present (i.e., metal emission concentrations reported as 

below detection limit or detection level limited were included in the total emissions reported). 

Direct measurements of total metals concentration were provided for all six SPA emission points 

we examined. Table 3.8 shows total metals emissions from specific stack emission points with 

outlier emissions data highlighted in red. It should be noted that even though we have identified 
Page 20 of 85

outlier emissions data, the outlier total metals emissions are very low (i.e., the total sum of all 

total metals emissions reported at SPA process lines, including outliers, is about 170 pounds of 

total metals per year); this analysis was only performed to see if the outliers are related to a 

control technology (when compared to all other emission points).

Table 3.8: Total Metals Emissions from Superphosphoric Acid Emission Points

Facility EP ID Control Technology

Total Metals

(gr/dscf)

(lbs/thousand 

tons of P2O5)

Agrium Nu-West1,2 Combined Crossflow Scrubber 4.54E-06 6.93E-03

Simplot Don-Pocatello1,3 EP-401 Packed Bed Scrubber 1.18E-05 1.10E-02

PCS White Springs EP-70.01 Other Scrubber Type 1.01E-04 4.38E-01

PCS Aurora EP-331 Venturi Scrubber 3.36E-06 1.89E-03

PCS Aurora EP-332 Venturi Scrubber 4.14E-06 4.25E-03

Simplot Rock Springs EP-40 Venturi Scrubber 1.48E-04 3.01E-01

Notes:

1. Emissions from the oxidation reactor process are included.

2. Emissions from the oxidation reactor process are uncontrolled.

3. Emissions from the oxidation reactor process are controlled.

The PCS White Springs emission point EP-70.01 and Simplot Rock Springs emission 

point EP-40 each emit at least 17 times higher total metals concentration compared to the

average of the rest of the entire population of total metals concentration data. When normalized 

to total metals emissions (pounds metals / thousand tons P2O5), these emission points are each at 

least 50 times higher than the average of the rest of the population of data.

We are unable to conclude whether control technology plays a role on the PCS White 

Spring outlier total metals emissions data point because we do not know the type of scrubber 

being used to control this specific SPA process line. As indicated in the facility’s air permit, the 

Simplot Rock Springs emission point EP-40 uses a venturi scrubber. This outlier total metals 

emissions point does not appear to be related to the control technology because there are other 

emission points with similar control technologies that reported much lower emissions. 

3.2.4 Mercury Emission Outliers for Superphosphoric Acid Emission Points Reported

Direct measurements of Hg concentration (using Method 30B) were provided for four of 

the six SPA emission points we examined. Direct measurements of Hg concentration using the 

Ontario-Hydro Method were also provided by facilities, but we used the measurements 

associated with Method 30B because the method typically results in better detection limits. Table 

3.9 shows Hg emissions from specific stack emission points with outlier emissions data 

highlighted in red. It should be noted that even though we have identified outlier emissions data, 

the outlier Hg emissions are very low (i.e., the total sum of all Hg emissions reported at SPA 

process lines, including outliers, is less than 1.0 pound of Hg per year); this analysis was only 

performed to see if the outliers are related to a control technology (when compared to all other 

emission points).
Page 21 of 85

Table 3.9: Mercury Emissions from Superphosphoric Acid Emission Points

Facility EP ID Control Technology

Mercury

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West1,2 Combined Crossflow Scrubber 2.98E-08 4.33E-05

Simplot Don-Pocatello1,3 EP-401 Packed Bed Scrubber 1.84E-07 2.05E-04

PCS White Springs EP-70.01 Other Scrubber Type 2.49E-08 1.35E-04

PCS Aurora EP-331 Venturi Scrubber NA NA

PCS Aurora EP-332 Venturi Scrubber NA NA

Simplot Rock Springs EP-40 Venturi Scrubber 1.53E-07 3.28E-04

Notes:

1. Emissions from the oxidation reactor process are included.

2. Emissions from the oxidation reactor process are uncontrolled.

3. Emissions from the oxidation reactor process are controlled.

The Simplot Don-Pocatello emission point EP-401 and Simplot Rock Springs emission 

point identified EP-40 each emit at least five and one-half times higher Hg concentration 

compared to the average of the rest of the entire population of Hg concentration data. When 

normalized to Hg emissions (pounds Hg per thousand tons P2O5), the Simplot Rock Springs 

emission point identified EP-40 is about two and one-half times higher than the average of the 

rest of the population of data.

The outlier total metals emissions data for Simplot Don-Pocatello may be related to the 

packed bed scrubbing technology being used; however, it is difficult to be certain because there 

are no other emission points that operate a similar scrubber to compare. The Simplot Rock 

Springs emission point EP-40 uses a venturi scrubber; this outlier Hg emission point does not 

appear to be related to the control technology because there are other emission points with 

similar control technologies that reported much lower emissions.

3.2.5 Particulate Matter Emission Outliers for Superphosphoric Acid Emission Points 

Reported

Direct measurements of PM concentration were provided for all six SPA emission points 

we examined. Table 3.10 shows PM emissions from specific stack emission points with outlier 

emissions data highlighted in red.

Table 3.10: Particulate Matter Emissions from Superphosphoric Acid Emission Points

Facility EP ID Control Technology

Particulate Matter

(gr/dscf) (lbs/thousand 

tons of P2O5)

Agrium Nu-West1,2 Combined Crossflow Scrubber 7.73E-04 1.60

Simplot Don-Pocatello1,3 EP-401 Packed Bed Scrubber 4.13E-03 3.92

PCS White Springs EP-70.01 Other Scrubber Type 9.08E-04 5.22

PCS Aurora EP-331 Venturi Scrubber 3.38E-03 2.15E+00

PCS Aurora EP-332 Venturi Scrubber 5.32E-03 2.78
Page 22 of 85

Facility EP ID Control Technology

Particulate Matter

(gr/dscf) (lbs/thousand 

tons of P2O5)

Simplot Rock Springs EP-40 Venturi Scrubber 2.57E-03 5.79

Notes:

1. Emissions from the oxidation reactor process are included.

2. Emissions from the oxidation reactor process are uncontrolled.

3. Emissions from the oxidation reactor process are controlled.

The Simplot Don-Pocatello emission point EP-401 and PCS Aurora emission point EP332 each emit at least two times higher PM concentration compared to the average of the rest of 

the entire population of PM concentration data. When normalized to PM emissions (pounds

particulate per thousand tons P2O5), the Simplot Rock Springs emission point identified as EP-40

and PCS White Springs EP-70.01 are two times higher than the average of the rest of the 

population of data.

The outlier PM emissions data for Simplot Don-Pocatello may be related to the packed 

bed scrubbing technology being used; however, it is difficult to be certain because there are no 

other emission points that operate a similar scrubber to compare. The PCS Aurora emission point 

EP-332 and Simplot Rock Springs emission point EP-40 each use a venturi scrubber. These 

outlier PM emission points do not appear to be related to the control technology because there 

are other emission points with similar control technologies that reported much lower emissions.

We are unable to conclude whether control technology plays a role on the PCS White Spring 

outlier PM emissions data point because we do not know the type of scrubber being used to 

control this specific SPA process line.

3.3 Purified Phosphoric Acid Process Lines

PPA is used in technical and food grade manufacturing, although both technical and food 

grade acid can be produced through other processes. There is only one facility (PCS Aurora) 

located in the United States that produces PPA through a solvent extraction process. The 

following is a description of their operation for which we paraphrased from information provided 

in the section 114 responses. 

The PCS Aurora PPA operations consist of two process lines where phosphoric acid is 

mixed with a solvent in one of two extraction columns operated in parallel. The 

phosphoric acid-solvent extract streams enter one of two release columns (also operated 

in parallel). A stream of purified, low-alkali phosphoric acid is recovered from near the 

middle of each release column; a stream of purified, high-alkali phosphoric acid is 

recovered from near the bottom of each column. The high-alkali acid streams from the 

release columns are passed through stream strippers where residual solvent is removed 

and recycled to solvent storage tanks. These tanks (as well as other process vessels) are 

kept under a nitrogen blanket system that vents to a chilled stack where the solvent is 

condensed for reuse. Spray tower scrubbers control the fluoride emissions from the 

concentrators and defluorination columns in the low alkali acid and high alkali acid 

streams.
Page 23 of 85

As part of the section 114 request, PCS Aurora tested emission point EP-501 (which is 

associated with a chiller used to reclaim solvent), and emission point EP-502 (which is 

associated with a spray tower scrubber that controls emissions from one of their PPA process 

lines). EP-501 was only tested for MIBK. The emissions data are presented in Table 3.11; 

however, it is not possible to discern whether the control technology being used at these emission 

points is more (or less) effective than another because there are no other PPA solvent extraction

process lines to compare.

Table 3.11: Emissions from Purified Phosphoric Acid Solvent Extraction Emission Points

Pollutant

EP-501 EP-502

(gr/dscf) (lbs/thousand 

tons of P2O5)

(gr/dscf) (lbs/thousand

tons of P2O5)

Total Flourides NA NA 5.92E-04 5.00E-01

Hydrogen Flouride NA NA NA NA

Total Metals NA NA 2.03E-06 1.73E-03

Mercury NA NA NA NA

Total Particulate NA NA 1.07E-03 0.95

Methyl Isobutyl 

Ketone NA 44.3 NA NA

3.4 Phosphate Rock Dryers

As part of the section 114 request, PCS Aurora tested emission point EP-210 which is 

associated with a venturi scrubber that controls emissions from a phosphate rock dryer. The 

dryer was used to decrease moisture in the wet phosphate rock (downstream of mining and 

beneficiation) from approximately 10 percent moisture, to less than one percent moisture.

However, following the section 114 submission the facility indicated that the dryer is no longer 

used for the purpose of phosphoric acid production. The emissions data are presented in Table 

3.12; however, it is not possible to discern whether the control technology being used at this 

emission points is more (or less) effective than another because there are no other phosphate rock 

dryer emission data to compare. The PM emissions from EP-210 are below the current NESHAP 

emission limit of 0.215 pounds PM per ton P2O5.

Table 3.12: Emissions from Phosphate Rock Dryer Emission Points

Pollutant

EP-210

(gr/dscf) (lbs/thousand 

tons of P2O5)

Total Flourides 3.09E-04 1.21

Hydrogen Flouride 8.27E-05 2.80E-01

Total Metals 4.93E-05 1.78E-01

Mercury 3.06E-07 1.13E-03

Total Particulate 1.72E-02 54.5
Page 24 of 85

3.5 Phosphate Rock Calciners

There is only one facility (PCS Aurora) located in the United States that operates 

phosphate rock calciners. These fluidized bed calciners (a total of six at PCS Aurora) remove 

organic impurities from the phosphate rock prior to acidulation with sulfuric acid to form 

phosphoric acid. The calciners consist of a pre-heat section, fluidized bed calcination, and a 

cooling compartment for the calcined rock. Emissions from the pre-heat section and the cooling 

compartment of each calciner exhaust through individual cyclones and a venturi scrubber, using 

water as the scrubbing solution. Each calciner is also equipped with a wet electrostatic 

precipitator (WESP) following the scrubber for additional emissions control. These calciners had 

wet scrubbers installed prior to the current NESHP PM limits being promulgated. To meet the 

current PM limits, the facility added WESP in addition to the previously installed wet scrubbers. 

The emissions data are presented in Table 3.13; however, it is not possible to discern whether the 

control technology being used at these emission points is more (or less) effective than another 

because there are no other phosphate rock calciner emission data to compare. The PM emissions 

are below the current NESHAP emission limit of 0.080 grains PM per dry standard cubic foot.

Based on the data submitted by facilities in response to the April 2010 CAA section 114 request, 

PM emissions from these units vary from 0.0012 to 0.0695 grains PM per dry standard cubic 

foot. This range of emissions indicates that the current limits represent expected performance of 

the control technology configuration. Also, the Hg emissions are considerably higher than any 

other emission source located at a phosphoric acid manufacturing plant (i.e., Hg emissions from 

phosphate rock calciners are approximately 98 percent of the total Hg emissions attributed to the 

phosphoric acid manufacturing plant source category).

Table: 3.13: Emissions from Phosphate Rock Calciner Emission Points

Pollutant

EP-203

(gr/dscf) (lbs/thousand 

tons of P2O5)

Total Flourides 1.06E-04 4.46E-01

Hydrogen Flouride 1.66E-04 1.51

Total Metals 6.25E-06 4.57E-02

Mercury 1.44E-05 8.16E-02

Total Particulate 3.80E-03 25.9

3.6 Diammonium and/or Monoammonium Phosphate Fertilizer Process Lines

An APF process line typically consists of a reaction step (where anhydrous ammonia is 

reacted with phosphoric acid to form diammonium phosphate and monoammonium phosphate), a 

granulation step (where solidification occurs), and finishing operations (where the solid material 

is dried, cooled, and sent through a screening arrangement for particle segregation). 

EPA received emissions data for 14 different emission points in APF process lines. We 

analyzed the arrangement of equipment that exhausts through each of these emission points and 

determined that it was necessary to combine (i.e., by summing the reported emissions) the three

Simplot Don-Pocatello emission points (EP-101; EP-102; and EP-103); as well as the two 

Mississippi Phosphates emission points (EP-1 and EP-2), in order to evaluate against existing 
Page 25 of 85

emissions limits, obtain a complete representation of total emissions associated with an 

individual APF process line, and to perform consistent comparisons between individual APF 

process lines. We also determined that CFI Plant City reported two sets of emissions for the 

same emission point (i.e., the facility based these two sets of emissions on the type of APF 

process they tested); therefore, for simplicity we chose to consider only the set with higher 

emissions. This methodology for consolidating emission points into individual process lines is 

consistent with the method of compliance for the current rule.

In general, there is a consistent arrangement of equipment which exhausts to control

technologies at APF process lines. For nine of the 11 APF emission points we examined,

emissions from reactors and granulators are combined before going to a wet scrubber followed 

by another (final) wet scrubber. For these nine APF emission points, the dryer, screen, mill, and 

cooler emissions are fed individually or combined to cyclones, followed by a wet scrubber, and 

are also sent to the final wet scrubber. The primary difference between these nine APF emission 

points is inherent to the type of wet scrubber(s) being used. The remaining APF emission points 

we examined (that are associated with reactors and granulators) operate only one non-packed bed 

wet scrubber. Tables 3.14 through 3.17 show how we categorized each APF emission point 

based on equipment and control technology configuration. Table 3.18 provides a legend for each 

“specific equipment and control technology layout” presented in Tables 3.14 through 3.17. 
Page 26 of 85

Table 3.14: Ammonium Phosphate Fertilizer Emission Point Configuration A

 Reactor/granulator operations vent through at least one venturi scrubber, and always a single packed bed (or impingement) scrubber in series.

 Dryer operations vent through a cyclone, at least one venturi scrubber, and always a single packed bed (or impingement) scrubber in series.

 Screen, Mill, and Cooler operations vent through a cyclone, a venturi scrubber, and a single packed bed scrubber (or impingement) in series.

Facility Process ID EP Specific Equipment and Control Technology Layout Final Control 

Technology

Mosaic New Wales P-2 EP-05 ScrImFW(ScrVPA(PreScrubber(Reactor,Granulator)+Cycl(Screens,Mill)+Cycl(Cooler))+

ScrVPA(Cycl(Dryer)))

Scrubber -

Impingement

CFI Plant City Y-DAP/

Y-MAP EP-stack ScrPBFW(ScrVPW(ScrVPA(Reactor,Granulator))+ScrVPW(ScrVPA(Cycl(Dryer)))+ScrVPA(Cycl(Screens,Mills))+ScrVPW(Cycl(Cooler)))

Scrubber -

Packed Bed

Mosaic Bartow P-23 EP-2

ScrPBPW(ScrVPA(Cycl(Dryer)))+ScrPBPW(ScrVPA((Reactor,Granulator)+Cycl(Screens,Mills))+

ScrVPW(Cycl(Cooler)))

Scrubber -

Packed Bed

PCS Aurora 303 EP-303 ScrPBFW(ScrVPA(Reactor,Granulator)+ScrVPA(Cycl(Screens,Mill)+Cycl(Cooler)))+

ScrPBFW(ScrVPA(Cycl(Dryer)))

Scrubber -

Packed Bed

Simplot Rock 

Springs P-1 EP-10 Not available, PFD is CBI Scrubber -Packed Bed

**This drawing is intended to assist the reader in understanding Configuration A; however, it does not reflect the actual quantity of the equipment and/or 

control technologies located at each facility. For example, the dryer emissions may feed to the same controls used by the screens, mills, and cooler (and not to 

a separate, dedicated set of controls); this example would still be considered Configuration A.**
Page 27 of 85

Table 3.15: Ammonium Phosphate Fertilizer Emission Point Configuration B

 Reactor/granulator operations vent through at least two wet scrubbers in series (no packed bed scrubbers).

 Dryer operations vent through a cyclone, and two wet scrubbers in series (no packed bed scrubbers).

 Screen, Mill, and Cooler operations vent through a cyclone, and two wet scrubbers in series (no packed bed scrubbers).

Facility Process 

ID EP Specific Equipment and Control Technology Layout Final Control Technology

PCS Aurora 302 EP-302 ScrUFWCa(ScrVProcW(Reactor,Granulator)+ScrUProcW(Cycl(Dryer))+

ScrUProcW(Cycl(Screens,Mills))+ScrUProcW(Cycl(Cooler)))

Scrubber -

Unknown

Mosaic Faustina P-43 EP-07 ScrVPW(ScrU(Reactor)+ScrU(Granulator)+ScrU(Cycl(Dryer))+ScrU(Cycl(Screens,Mill,Cooler)))

Scrubber -

Venturi

MS Phosphatesa P-2 EP-1 Not available, PFD is CBI Baghouse

MS Phosphatesa P-2 EP-2 Not available, PFD is CBI Scrubber -

Unknown

a— In order to use MS Phosphates emissions data, EP-1 and EP-2 were added together because the equipment associated with these emission points are similar to the type of equipment and control as the other configuration B

emission points; however, the emissions exit two stacks instead of one. Note: emissions from EP-2 are only vented through a baghouse in lieu of a cyclone and two scrubbers in series. 

**This drawing is intended to assist the reader in understanding Configuration B; however, it does not reflect the actual quantity of the 

equipment and/or control technologies located at each facility. For example, the dryer emissions may feed to the same controls used by 

the screens, mills, and cooler (and not to a separate, dedicated set of controls); this example would still be considered Configuration B.**
Page 28 of 85

Table 3.16: Ammonium Phosphate Fertilizer Emission Point Configuration C

 Reactor/granulator operations vent through one venturi scrubber.

 Dryer operations vent through one venturi scrubber.

 Screen, Mill, and Cooler operations vent through at least a baghouse.

Facility Process 

ID EP Specific Equipment and Control Technology Layout Final Control Technology

Agrium Nu-West Gran EP-6 ScrVRW(Cycl(Dryer+BH(Cooler,Screens,Mills)))+ScrVRW(Reactor,Granulator)

Scrubber -

Venturi

Simplot DonPocatelloa P-1 EP-101 ScrVProcWPA(Reactor,Granulator)Scrubber -

Venturi

Simplot DonPocatelloa P-1 EP-102 ScrVProcWPA(Dryer)Scrubber -

Venturi

Simplot DonPocatelloa P-1 EP-103 Not available, PFD is CBI Baghouse

a—In order to use Simplot Don-Pocatello emissions data, EP-101, EP-102, and EP-103 were added together because the equipment associated with these emission points are similar to the type of equipment and control as the other 

configuration C emission points; however, the emissions exit three stacks instead of one.

**This drawing is intended to assist the reader in understanding Configuration C; however, it does not reflect the actual quantity of the 

equipment and/or control technologies located at each facility. For example, the dryer emissions may feed to the same venturi scrubber as 

the reactor and granulator (and not to a separate, dedicated venturi scrubber); this example would still be considered Configuration C.**
Page 29 of 85

Table 3.17: Ammonium Phosphate Fertilizer Emission Point Configuration D

 Reactor/granulator operations vent through one venturi scrubber and two packed bed scrubber in series.

 Dryer operations vent through a cyclone, venturi scrubber, and two packed bed scrubber in series.

 Screen and Mill operations vent through a cyclone, venturi scrubber, and two packed bed scrubber in series. (no cooler operations)

Facility Process 

ID EP Specific Equipment and Control Technology Layout

Final 

Control 

Technology

PCS White Springs 32 EP-32 ScrPBCaFW(ScrPBPW(ScrVPA(Reactor,Granulator))+ScrPBPW(ScrVPA(Cycl(Dryer)))+

ScrPBPW(ScrVPA(Cycl(Screens,Mills))))

Scrubber -

Packed Bed

**This drawing is intended to assist the reader in understanding Configuration D; however, it does not reflect the actual 

quantity of the equipment and/or control technologies located at each facility. For example, the dryer emissions may feed to

the same controls used by the screens and mills (and not to a separate, dedicated set of controls); this example would still be 

considered Configuration D.**
Page 30 of 85

Table 3.18: Legend For Specific Control Technology Layout For Ammonium

Phosphate Fertilizer Emission Points

Abbreviations Used For Control Technology Layout

Cycl Cyclone

BH Baghouse

Scr Scrubber

Abbreviations Specific To Scrubbers

Scrubber Types:

U Unknown Scrubber Type, Information Was Not Provided

V Venturi Scrubber

C Crossflow Scrubber

PB Packed Bed Scrubber

Im Impingement Scrubber

Cy Cyclonic Scrubber

ST Spray Tower

Scrubbing Liquid:

PW = Pond Water

FW = Fresh Water

ProcW = Process Water

PA = Phosphoric Acid

Ca = Caustic

RW = Recirculating Water

As an example, a packed bed scrubber which uses pond water as the scrubbing liquid is 

displayed in Tables 3.14 through 3.17 as “ScrPBPW”. In certain cases multiple liquids are used; 

when this occurs, both liquid abbreviations are then provided one after the other.
Page 31 of 85

The following subsections of this report discuss the emissions from specific APF

emission points (grouped by configuration) considered to be outlier emissions data. For the 

purposes of this analysis, we considered emissions data an outlier if the emissions were located 

in the upper 33 percent of the full range of available data (the range was determined by plotting 

all available emission points for a specific pollutant using a uniform, even spread that was based 

on the lowest and highest emissions for that specific pollutant). These outlier emissions data may 

be more easily identified by referencing the charts provided in Appendix D.

3.6.1 Total Fluoride Emission Outliers for Ammonium Phosphate Fertilizer Emission Points 

Reported

Direct measurements of TF concentration were provided for nine of the 11 APF emission 

points we examined. Table 3.19 shows TF emissions from specific stack emission points 

(grouped by configuration) with outlier emissions data highlighted in red. 

Table 3.19: Total Fluoride Emissions from Ammonium Phosphate Fertilizer Emission Points 

Grouped By Configuration

Facility EP ID Configuration

Total Fluorides

(gr/dscf) (lbs/thousand 

tons of P2O5)

Mosaic New Wales EP-05 A 3.42E-03 61.9

CFI Plant City EP-stack A 3.26E-04 8.87

Mosaic Bartow EP-2 A 3.80E-04 6.45

PCS Aurora EP-303 A 6.79E-04 16.0

Simplot Rock Springs EP-10 A 1.40E-04 2.94

PCS Aurora EP-302 B 6.27E-05 1.21

Mississippi Phosphates Combined B NA NA

Mosaic Faustina EP-07 B NA NA

Simplot Don-Pocatello Combined C 2.58E-04 4.39

Agrium Nu-West EP-6 C 3.79E-03 53.4

PCS White Springs EP-32 D 1.17E-03 29.2

The Mosaic New Wales EP-05 and Agrium Nu-West EP-6 emission points each emit at 

least eight times the TF concentration compared to the average of the rest of population of total F 

concentration data. When normalized to TF emissions (pounds TF / thousand tons P2O5), the 

emission points are more than five and one-half times higher than the average of the rest of the 

population of data. 

The Mosaic New Wales emission point follows configuration A and Agrium Nu-West 

emission point EP-6 uses configuration C (see Table 3.16). These outlier TF emissions data do 

not appear to be related to the control technology because there are other emission points of 

similar configurations that reported lower emissions.
Page 32 of 85

3.6.2 Hydrogen Fluoride Emission Outliers for Ammonium Phosphate Fertilizer Emission 

Points Reported

Direct measurements of HF concentration were provided for 10 of the 11 APF emission 

points we examined. Table 3.20 shows HF emissions from specific stack emission points 

(grouped by configuration) with outlier emissions data highlighted in red.

Table 3.20: Hydrogen Fluoride Emissions from Ammonium Phosphate Fertilizer Emission Points 

Grouped By Configuration

Facility EP ID Configuration

Hydrogen Fluoride

(gr/dscf) (lbs/thousand 

tons of P2O5)

Mosaic New Wales EP-05 A 3.38E-03 59.1

CFI Plant City EP-stack A NA NA

Mosaic Bartow EP-2 A 1.36E-03 23.4

PCS Aurora EP-303 A 2.16E-03 42.3

Simplot Rock Springs EP-10 A 2.20E-04 4.89

PCS Aurora EP-302 B 8.07E-05 2.10

Mississippi Phosphates Combined B 2.00E-03 41.9

Mosaic Faustina EP-07 B 3.14E-05 0.86

Simplot Don-Pocatello Combined C 3.03E-04 5.86

Agrium Nu-West EP-6 C 1.52E-02 208.2

PCS White Springs EP-32 D 1.09E-03 22.1

The Agrium Nu-West emission point EP-6 emits about 13 times the HF concentration 

compared to the average of the rest of population of HF concentration data. When normalized to 

HF emissions (pounds HF per thousand tons P2O5), the emission point is about nine times higher 

than the average of the rest of the population of data.

The Agrium Nu-West emission point EP-6 uses the control technology identified in 

configuration C (see Table 3.16). This outlier HF emissions point does not appear to be related to 

the control technology because there are other emission points of similar configuration that 

reported much lower emissions.

3.6.3 Total Metals Emission Outliers for Ammonium Phosphate Fertilizer Emission Points 

Reported

The total metals analysis discussion is based on a review of all the metals data (excluding 

Hg and P) even if non-detect data were present (i.e., metal emission concentrations reported as 

below detection limit or detection level limited were included in the total emissions reported). 

Direct concentration measurements of total metals were provided for all 11 APF emission points 

we examined. Table 3.21 shows total metals emissions from specific stack emission points 

(grouped by configuration) with outlier emissions data highlighted in red. It should be noted that 

even though we have identified outlier emissions data, the outlier total metals emissions are very 

low (i.e., the total sum of all total metals emissions reported at APF process lines, including 
Page 33 of 85

outliers, is about 1.0 ton of total metals per year); this analysis was only performed to see if the 

outliers are related to a control technology (when compared to all other emission points).

Table 3.21: Total Metals Emissions from Ammonium Phosphate Fertilizer Emission Points 

Grouped By Configuration

Facility EP ID Configuration

Total Metals

(gr/dscf) (lbs/thousand 

tons of P2O5)

Mosaic New Wales EP-05 A 1.29E-05 2.42E-01

CFI Plant City EP-stack A 1.79E-05 4.68E-01

Mosaic Bartow EP-2 A 5.96E-06 9.72E-02

PCS Aurora EP-303 A 2.27E-05 4.72E-01

Simplot Rock Springs EP-10 A 3.46E-06 7.36E-02

PCS Aurora EP-302 B 1.02E-05 3.02E-01

Mississippi Phosphates Combined B 8.61E-05 1.76

Mosaic Faustina EP-07 B 1.56E-05 4.41E-01

Simplot Don-Pocatello Combined C 1.12E-05 2.01E-01

Agrium Nu-West EP-6 C 4.39E-06 8.28E-02

PCS White Springs EP-32 D 9.35E-06 1.92E-01

The Mississippi Phosphates combined emission point (EP-1 and EP-2) has a significantly 

higher (about seven times higher) total metals concentration and normalized emissions when 

compared to the average of the rest of the population of total metals data.

The Mississippi Phosphates emission point EP-2 uses the control technology identified in 

configuration B (see Table 3.15). This outlier total metals emissions data point does not appear 

to be related to the control technology because there are other emission points of similar 

configuration that reported much lower emissions.

3.6.4 Mercury Emission Outliers for Ammonium Phosphate Fertilizer Emission Points 

Reported

Direct measurements of Hg concentration (using Method 30B) were provided for six of 

the 11 APF emission points we examined; however, we did not use one of these measurements 

because there were no test method verification tests included with the measurement. Direct 

measurements of Hg concentration using the Ontario-Hydro Method were also provided by 

facilities, but we used the measurements associated with Method 30B because the method 

typically results in better detection limits. Table 3.22 shows Hg emissions from specific stack 

emission points with outlier emissions data highlighted in red. It should be noted that even 

though we have identified outlier emissions data, the outlier Hg emissions are very low (i.e., the 

total sum of all Hg emissions reported at APF process lines, including outliers, is about 38.0 

pounds of Hg per year); this analysis was only performed to see if the outliers are related to a 

control technology (when compared to all other emission points).
Page 34 of 85

Table 3.22: Mercury Emissions From Ammonium Phosphate Fertilizer Emission Points Grouped 

By Configuration

Facility EP ID Configuration

Mercury

(gr/dscf) (lbs/thousand 

tons of P2O5)

Mosaic New Wales EP-05 A NA NA

CFI Plant City EP-stack A 1.23E-07 3.32E-03

Mosaic Bartow EP-2 A NA NA

PCS Aurora EP-303 A NA NA

Simplot Rock Springs EP-10 A 3.03E-08 8.78E-04

PCS Aurora EP-302 B NA NA

Mississippi Phosphates Combined B 2.09E-07 4.65E-03

Mosaic Faustina EP-07 B NA NA

Simplot Don-Pocatello Combined C 5.25E-07 9.96E-03

Agrium Nu-West EP-6 C 4.46E-08 5.75E-04

PCS White Springs EP-32 D 4.01E-08 8.73E-04

The Simplot Don-Pocatello combined emission point (EP-101, EP-102, and EP-103) has 

about six times higher Hg concentration and five times higher normalized emissions when 

compared to the average of the rest of the population of Hg data.

The Simplot Don-Pocatello process line uses the control technology identified in 

configuration C (see Table 3.15). This outlier total metals emissions data point does not appear 

to be related to the control technology because there are other emission points of similar 

configuration that reported much lower emissions.

3.6.5 Particulate Matter Emission Outliers for Ammonium Phosphate Fertilizer Emission 

Points Reported

Direct measurements of PM concentration were provided for 10 of the 11 APF emission 

points we examined. Table 3.23 shows PM emissions from specific stack emission points 

(grouped by configuration) with outlier emissions data highlighted in red.

Table 3.23: Particulate Matter Emissions from Ammonium Phosphate Fertilizer Emission Points 

Grouped By Configuration

Facility EP ID Configuration

Particulate Matter

(gr/dscf) (lbs/thousand 

tons of P2O5)

Mosaic New Wales EP-05 A 1.13E-02 203

CFI Plant City EP-stack A NA NA

Mosaic Bartow EP-2 A 8.09E-03 135

PCS Aurora EP-303 A 9.66E-03 211

Simplot Rock Springs EP-10 A 3.48E-03 75.9
Page 35 of 85

Facility EP ID Configuration

Particulate Matter

(gr/dscf) (lbs/thousand 

tons of P2O5)

PCS Aurora EP-302 B 3.50E-03 92.9

Mississippi Phosphates Combined B NA NA

Mosaic Faustina EP-07 B 5.92E-02 1677

Simplot Don-Pocatello Combined C 1.50E-02 263

Agrium Nu-West EP-6 C 1.35E-02 178

PCS White Springs EP-32 D 4.65E-03 108

The Mosaic Faustina emission point EP-07 emits about seven times the PM concentration 

compared to the average of the rest of population of PM concentration data. When normalized to 

PM emissions (pounds particulate per thousand tons P2O5), the emission point is about 10 times 

higher than the average of the rest of the population of data. 

The Mosaic Faustina emission point EP-07 uses the control technology identified in 

configuration B (see Table 3.15). This outlier PM emissions point does not appear to be related 

to the control technology because there are other emission points of similar configuration that 

reported much lower emissions.

3.7 Triple Superphosphate Process Lines and Storage Buildings

TSP is a phosphate fertilizer process, but none of the 11 facilities with APF processes 

have active operations for TSP production or storage based on the section 114 responses. 

Therefore, emissions data and currently used controlled technologies were not available for 

comparison. While one facility is permitted to store GTSP, we do not anticipate that the facility 

will resume GTSP operations at any point in the future because North American production of 

TSP ceased in 2007 (IFA, 2014). Figure 1 below shows how production and consumption of TSP 

have decreased since 2002. Also note that all TSP consumed in North America since 2007 is 

imported. 

However, if a facility were to start producing and storing TSP, the control technologies 

would be the same as those already used at APF process lines because the same, or very similar, 

equipment is used to produce and store TSP as what is used to produce and store APF (U.S. 

EPA, 1996). TSP production and storage emission limits are also only specified for TF, which is 

the same pollutant specified for APF process lines. Because we did not identify any new control 

technologies for APF production, no new control technologies are applicable for TSP production 

and storage processes.
Page 36 of 85

Figure 1. Plot of production and consumption of TSP in North America from 2002 to 2012 (IFA, 

2014).

3.8 Conclusions

Based on a review of the section 114 responses, we have determined that the control 

technologies used at phosphoric acid manufacturing and phosphate fertilizer production plants

have not changed since the original NESHAP and NSPS regulations. For the NESHAP 

technology review specifically, the control technologies used were previously discussed in the 

memorandum entitled National Emission Standards for Hazardous Air Pollutants from 

Phosphoric Acid Manufacturing and Phosphate Fertilizers Production; Proposed Rules – Draft 

Technical Support Document and Additional Technical Information (U.S. EPA, 1996). In 

general, the phosphoric acid manufacturing and phosphate fertilizer production source categories 

still use wet scrubbing technology to control TF and HF emissions from the various processes 

located at these source categories (i.e., WPPA, SPA, PPA, and APF processes). However, the 

type and configuration of the wet scrubbing technology varies significantly between facilities 

and between process lines within a facility. Furthermore, we have not found any developments in 

wet scrubbing methods used at phosphoric acid manufacturing and phosphate fertilizer 

production plants. All control technologies used by each facility are also necessary to comply 

with the current emissions limitations, and revised emissions limitations beyond those currently 

required are not appropriate.

Even though wet scrubbers are the most common control technology used at phosphoric 

acid manufacturing and phosphate fertilizer production plants, a wet scrubber’s ability to control 

Hg emissions is minimal. There are two main control technology options for removal of Hg that 
Page 37 of 85

are currently employed in other industries; activated carbon injection (ACI) with fabric filters, 

and fixed-bed carbon adsorption. Based on information provided in the Sewage Sludge 

Incinerators (SSI) preamble (U.S. EPA, 2011a) and Response to Comments memorandum (U.S. 

EPA, 2011b), the use of ACI may pose challenges for the phosphate industry. It was noted in 

these SSI documents that for streams with high moisture content, the use of ACI was not 

possible due to the plugging of fabric filters which are necessary after ACI to collect the 

activated carbon media. Multiple emission points at phosphoric acid and phosphate fertilizer 

process units have moisture contents between 20 and 40 percent moisture and thus the use of 

ACI may not be practical. For fixed-bed carbon adsorption, while moisture content is certainly a 

factor to consider, it is more manageable to control high moisture streams because a fabric filter 

is not required to collect particulate. Therefore, a case-by-case look at the stream properties 

would be necessary to determine the Hg control technology most suitable for a particular 

emission point; further detail is provided in a separate memorandum entitled “Control Costs and 

Emissions Reductions for Phosphoric Acid and Phosphate Fertilizer Production Source 

Categories” (ERG, 2014b).

For WPPA process lines, the outlier emissions data that we discuss in Section 3.1 of this 

memorandum may be related to the control technology being used; however, it is difficult to 

discern because each WPPA process line operates a unique equipment and control technology

configuration (i.e., there are no WPPA process lines that operate similar configurations to 

compare).

We observed some differences in total F emissions from SPA process lines. However, we 

did not find any patterns in emissions reductions based on control technology used because most 

of the SPA process lines that were tested operate a unique equipment and control technology 

configuration. For all SPA process lines that we examined, emissions from the evaporators are 

sent to a single wet scrubber, but the type of wet scrubber used at these SPA process lines varies. 

Some SPA process lines include an oxidation step to remove organic impurities from the 

acid. For Agrium Nu-West, we noted relatively high HF emissions from a currently uncontrolled 

oxidation process and control technology may be necessary. The application of wet scrubbing 

control technology would be consistent with other SPA process lines, where all applicable 

emission points are controlled by wet scrubbers. We believe the use of wet scrubbing control 

technology would result in a reduction of emission from the identified oxidation process to levels 

consistent with other industry wide SPA emissions. Agrium Nu-West already has wet scrubbing 

technology for their SPA process line, and we believe the facility would only need to install 

additional ductwork from the uncontrolled emission point to the wet scrubber. Therefore, it 

would not be necessary to install a new wet scrubber to control the oxidation process emissions. 

See the memorandum “Control Costs and Emissions Reductions for Phosphoric Acid and 

Phosphate Fertilizer Production Source Categories” (ERG, 2014b) for additional discussion 

regarding the uncontrolled oxidation process. 

For PPA process lines, phosphate rock dryers, and phosphate rock calciners (each 

emission source is discussed separately in Sections 3.3, 3.4, and 3.5 of this memorandum, 

respectively), it is difficult to discern whether the control technology being used at these 

emission points are more (or less) effective than another because there is minimal emission data

to compare.
Page 38 of 85

One could potentially conclude that for APF process lines (as discussed in Section 3.6 of 

this memorandum), APF control technology associated with configuration D (see Table 3.17) 

provides the best level of control for TF, HF, total metal (excluding Hg and P), Hg, and PM 

emissions because there were no outlier emissions data associated with this configuration. 

Configuration D uses two wet scrubbers in series and the final wet scrubber is a packed bed 

scrubber. However, there is only one process line associated with configuration D, so ample 

evidence is not available. In addition, we noted that for every outlier APF emission point that 

uses control technology associated with configurations A, B, or C, there are other emission 

points of similar configuration that reported much lower emissions. This indicates that control 

technology associated with configurations A, B, and C could be designed to be just as good at 

controlling emissions as control technology associated with configuration D.

For APF process lines, configurations B and C have outlier emissions data for all of the 

pollutants. Although in each instance the outlier data is attributed to a different facility, thus 

there is no consistency to determine distinguishing characteristics. Furthermore, even though 

configurations B and C were associated with each outlier emission point for all pollutants 

analyzed, if the outliers are excluded, then comparison of the remaining data shows similar 

concentration and normalized emissions for all control technology and associated configurations.

It is likely that the outlier emissions data discussed in this memorandum, except for one 

SPA process line, are caused by something other than inadequate control technology (e.g., subtle 

differences in sampling and analytical techniques, age of control equipment, and differences in 

facility operation). Without control technology efficiency data it is not possible to truly 

determine which control technologies are more effective at controlling emissions. 

For TSP process lines and storage buildings, none of the facilities with APF processes 

have active operations for TSP. Even so, since TSP equipment is similar to APF equipment and

because we did not identify any new control technologies for APF production, no new control 

technologies are applicable for TSP production and storage.

Although one of the primary purposes of Section 3.0 of this memorandum was to 

determine whether outlier emissions data associated with specific stack emission points were 

related to a control technology (when compared to all other emission points), we also made some 

general observations regarding total stack emissions from various processes located at the 

phosphoric acid manufacturing and phosphate fertilizer production source categories (i.e., 

WPPA, SPA, PPA, and APF processes). We observed that stack emissions contribute only about 

5.5 percent (or 124 tons per year) of the total HF emissions associated with the entire phosphoric 

acid manufacturing and phosphate fertilizer production source categories; the majority (about 95 

percent) of the HF emissions come from fugitive emissions associated with gypsum dewatering 

stacks, cooling ponds, and cooling towers which are discussed in Section 4.0 of this 

memorandum. We also observed that total metals emissions (excluding Hg and P) from all 

WPPA, SPA, PPA, and APF process lines combined equal approximately 1.5 tons per year; and 

the majority of Hg stack emissions (about 80 percent, or 244 pounds per year) come from the 

phosphate rock calciners; only about 12 percent, or 38 pounds Hg per year come from the APF 

process lines, and the remaining 20 pounds of Hg per year come from WPPA, SPA, and PPA 

process lines combined. 
Page 39 of 85

4.0 FUGITIVE EMISSIONS

Fugitive emissions from gypsum dewatering stacks, cooling ponds, and cooling towers 

have been identified as significant sources of HF emissions. Emission factors for gypsum 

dewatering stacks and ponds were derived from radial plume mapping test data performed at six 

facilities in the US and Canada (ERG, 2014c). Emissions from cooling towers were determined 

using data provided by each of the facilities that operated cooling towers which used water 

containing fluorides. The estimates of HF from these sources were approximately 95 percent of 

the total HF emissions for the phosphoric acid and phosphate fertilizer production source 

categories. While these sources have significant HF emissions, they are not regulated under the 

current NESHAP and NSPS and are thus considered unregulated sources. The CAA section 

111(b)(1)(B) and 112(d)(6) reviews are only applicable to currently regulated sources, and as 

such these fugitive emissions sources were not considered for either review.
Page 40 of 85

5.0 REFERENCES

Eastern Research Group, Inc. (ERG). 2014a. Information Collection and Additional Data 

Received for the Phosphoric Acid and Phosphate Fertilizer Production Source Categories. 

Prepared for the U.S. EPA Office of Air Quality Planning and Standards, Research 

Triangle Park, NC. Available at www.regulations.gov in Docket ID No. EPA-HQ-OAR2012-0522.

Eastern Research Group, Inc. (ERG). 2014b. Control Costs and Emissions Reductions for 

Phosphoric Acid and Phosphate Fertilizer Production Source Categories. Prepared for the 

U.S. EPA Office of Air Quality Planning and Standards, Research Triangle Park, NC. 

Available at www.regulations.gov in Docket ID No. EPA-HQ-OAR-2012-0522

Eastern Research Group, Inc. (ERG). 2014c. Phosphoric Acid and Phosphate Fertilizer 

RTR Modeling File Development. Prepared for the U.S. EPA Office of Air Quality 

Planning and Standards, Research Triangle Park, NC. Available at www.regulations.gov 

in Docket ID No. EPA-HQ-OAR-2012-0522.

Eastern Research Group, Inc. (ERG). 2014d. Comparison of 40 CFR Part 60, subpart T 

(Standards of Performance for the Phosphate Fertilizer Industry: Wet-Process Phosphoric 

Acid Plants) and 40 CFR Part 63, subpart AA (National Emission Standards for 

Hazardous Air Pollution from Phosphoric Acid Manufacturing Plants. Prepared for the 

U.S. EPA Office of Air Quality Planning and Standards, Research Triangle Park, NC. 

Available at www.regulations.gov in Docket ID No. EPA-HQ-OAR-2012-0522.

Eastern Research Group, Inc. (ERG). 2014e. Comparison of 40 CFR Part 60, subpart U 

(Standards of Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid 

Plants) and 40 CFR Part 63, subpart AA (National Emission Standards for Hazardous Air 

Pollution from Phosphoric Acid Manufacturing Plants. Prepared for the U.S. EPA Office 

of Air Quality Planning and Standards, Research Triangle Park, NC. Available at 

www.regulations.gov in Docket ID No. EPA-HQ-OAR-2012-0522.

Eastern Research Group, Inc. (ERG). 2014f. Comparison of 40 CFR Part 60, subpart V 

(Standards of Performance for the Phosphate Fertilizer Industry: Diammonium Phosphate 

Plants) and 40 CFR Part 63, subpart BB (National Emission Standards for Hazardous Air 

Pollution from Phosphate Fertilizers Production Plants. Prepared for the U.S. EPA Office 

of Air Quality Planning and Standards, Research Triangle Park, NC. Available at 

www.regulations.gov in Docket ID No. EPA-HQ-OAR-2012-0522.

Eastern Research Group, Inc. (ERG). 2014g. Comparison of 40 CFR Part 60, subpart W 

and subpart X (Standards of Performance for the Phosphate Fertilizer Industry: Triple 

Superphosphate Plants and Granular Triple Superphosphate Storage Facilities) and 40 

CFR Part 63, subpart BB (National Emission Standards for Hazardous Air Pollution from 

Phosphate Fertilizers Production Plants. Prepared for the U.S. EPA Office of Air Quality 

Planning and Standards, Research Triangle Park, NC. Available at www.regulations.gov 

in Docket ID No. EPA-HQ-OAR-2012-0522.
Page 41 of 85

International Fertilizer Industry Association (IFA). 2014. Production and trade statistics: 

TSP table. Available at 

http://www.fertilizer.org/ifa/HomePage/STATISTICS/Production-and-trade.

U.S. EPA. 2002. Air pollution control cost manual, 6th ed. EPA/452/B-02-001.

U.S. EPA. 1996. Memorandum: National Emission Standards for Hazardous Air 

Pollutants from Phosphoric Acid Manufacturing and Phosphate Fertilizers Production; 

Proposed Rules – Draft Technical Support Document and Additional Technical 

Information. September 24, 1996. Available at www.regulations.gov in Docket ID No. 

A-94-02. 

U.S. EPA. 2011a. Preamble: EPA, Standards Of Performance For New Stationary 

Sources And Emission Guidelines For Existing Sources: Sewage Sludge Incineration 

Units, Final Rule. March 2011. Available at www.regulations.gov in Docket ID No. 

EPA-HQ-OAR-2009-0559.

U.S. EPA. 2011b. Comments: EPA, Standards Of Performance For New Stationary 

Sources And Emission Guidelines For Existing Sources: Sewage Sludge Incineration 

Units, Summary Of Public Comments And Responses. February 2011. Available at 

www.regulations.gov in Docket ID No. EPA-HQ-OAR-2009-0559.

U.S. EPA. 2012. RACT/BACT/LAER Clearinghouse. Available at 

http://cfpub.epa.gov/RBLC/.
Page 42 of 85

Appendix A
Page 43 of 85

Active Facilities(1) Located In The United States That Are Considered To Be Part Of 

The Phosphoric Acid Manufacturing And/Or Phosphate Fertilizer Production Source Categories

Facility Name Location Process Type(s) At Facility (1)

WPPA SPA PPA APF

Agriphos Fertilizer, LLC (2) Pasadena,

Texas Unknown Unknown Unknown Unknown

Agrium Nu-West Industries, Inc. Soda Springs,

Idaho   NA 

CF Industries, Inc. Plant City,

Florida  NA NA 

J.R. Simplot Company Pocatello,

Idaho    

J.R. Simplot Company Rock Springs,

Wyoming   NA 

Mississippi Phosphates 

Corporation

Pascagoula,

Mississippi  NA NA 

Mosaic Fertilizer, LLC

(Bartow Facility)

Bartow,

Florida   NA 

Mosaic Fertilizer, LLC

(Faustina Facility)

St. James Parish,

Louisiana NA NA NA 

Mosaic Fertilizer, LLC

(Riverview Facility)

Riverview,

Florida   NA 

Mosaic Fertilizer, LLC

(New Wales Facility)

Mulberry,

Florida  NA NA 

Mosaic Fertilizer, LLC

(Uncle Sam Facility)

St. James Parish,

Louisiana  NA NA NA

Potash Corporation (PCS) Aurora,

North Carolina    

Potash Corporation (PCS) Geismar,

Louisiana  NA NA NA

Potash Corporation (PCS) White Springs,

Florida   NA 

NA – Not Applicable

1 – As of April 13, 2010. 

2 – Based on response to the April 13, 2010 Section 114 request, this facility indicated to U.S. EPA that it would be 

shutdown by the end of 2012.
Page 44 of 85

Appendix B

Emissions by WPPA process Line
Page 45 of 85

0.00E+00

5.00E-0 4

1.00E-0 3

1.50E-0 3

2.00E-0 3

2.50E-0 3

3.00E-0 3

3.50E-0 3

4.00E-0 3

4.50E-0 3

Agrium NuWestCFI Plant City Mosaic New 

Wales

PCS Aurora 

P401/404

PCS Aurora 

P406/409

PCS White 

Springs

Simplot DonPocatelloMosaic Uncle 

Sam

PCS White 

Springs

PCS Geismar Mississippi 

Phosphates

Simplot Rock 

Springs

(EP-71; 283; 

3131; ATM; 

3241; & 6101)

(EP-stack) (EP-11; 12; & 

22)

(EP-401; 403; & 

404)

(EP-406; 408; & 

409)

(EP-69.01) (EP-501) (EP-01) (EP-20.01; & 

20.02)

(EP-5 ) (EP-1 ) (EP-50) Concentration (gr/dscf)

Total Fluorides Concentration by WPPA Process Line Not Reported
Page 46 of 85
Page 47 of 85

0.00E+00

5.00E-0 4

1.00E-0 3

1.50E-0 3

2.00E-0 3

2.50E-0 3

3.00E-0 3

3.50E-0 3

4.00E-0 3

Agrium NuWestCFI Plant City Mosaic New 

Wales

PCS Aurora 

P401/404

PCS Aurora 

P406/409

PCS White 

Springs

Simplot DonPocatelloMosaic Uncle 

Sam

PCS White 

Springs

PCS Geismar Mississippi 

Phosphates

Simplot Rock 

Springs

(EP-71; 283; 

3131; ATM; 

3241; & 6101)

(EP-stack) (EP-11; 12; & 

22)

(EP-401; 403; & 

404)

(EP-406; 408; & 

409)

(EP-69.01) (EP-501) (EP-01) (EP-20.01; & 

20.02)

(EP-5 ) (EP-1 ) (EP-50) Concentration (gr/dscf)

Hydrogen Fluoride Concentration by WPPA Process Line Not Reported
Page 48 of 85
Page 49 of 85

0.00E+00

5.00E-0 6

1.00E-0 5

1.50E-0 5

2.00E-0 5

2.50E-0 5

3.00E-0 5

Agrium NuWestCFI Plant City Mosaic New 

Wales

PCS Aurora 

P401/404

PCS Aurora 

P406/409

PCS White 

Springs

Simplot DonPocatelloMosaic Uncle 

Sam

PCS White 

Springs

PCS Geismar Mississippi 

Phosphates

Simplot Rock 

Springs

(EP-71; 283; 

3131; ATM; 

3241; & 6101)

(EP-stack) (EP-11; 12; & 

22)

(EP-401; 403; & 

404)

(EP-406; 408; & 

409)

(EP-69.01) (EP-501) (EP-01) (EP-20.01; & 

20.02)

(EP-5 ) (EP-1 ) (EP-50) Concentration (gr/dscf)

Total Metals (All Data) Concentration by WPPA Process Line
Page 50 of 85
Page 51 of 85
Page 52 of 85
Page 53 of 85
Page 54 of 85
Page 55 of 85

Appendix C

Emissions by SPA Process Line
Page 56 of 85

0.00E+00

5.00E-0 4

1.00E-0 3

1.50E-0 3

2.00E-0 3

2.50E-0 3

3.00E-0 3

3.50E-0 3

4.00E-0 3

4.50E-0 3

5.00E-0 3

Agrium Nu-West Simplot Don-Pocatello PCS White Springs PCS Aurora PCS Aurora Simplot Rock Springs

(EP-522; & 541) (EP-401) (EP-70.01) (EP-331) (EP-332) (EP-40) Concentration (gr/dscf)

Total Fluorides Concentration by SPA Process Line
Page 57 of 85
Page 58 of 85
Page 59 of 85
Page 60 of 85

0.00E+00

2.00E-0 5

4.00E-0 5

6.00E-0 5

8.00E-0 5

1.00E-0 4

1.20E-0 4

1.40E-0 4

1.60E-0 4

Agrium Nu-West Simplot Don-Pocatello PCS White Springs PCS Aurora PCS Aurora Simplot Rock Springs

(EP-522; & 541) (EP-401) (EP-70.01) (EP-331) (EP-332) (EP-40) Concentration (gr/dscf)

Total Metals (All Data) Concentration by SPA Process Line
Page 61 of 85
Page 62 of 85
Page 63 of 85
Page 64 of 85

0.00E+00

1.00E-0 3

2.00E-0 3

3.00E-0 3

4.00E-0 3

5.00E-0 3

6.00E-0 3

Agrium Nu-West Simplot Don-Pocatello PCS White Springs PCS Aurora PCS Aurora Simplot Rock Springs

(EP-522; & 541) (EP-401) (EP-70.01) (EP-331) (EP-332) (EP-40) Concentration (gr/dscf)

Total Particulate Concentration by SPA Process Line
Page 65 of 85
Page 66 of 85

Appendix D

Emissions By APF Process Line
Page 67 of 85
Page 68 of 85
Page 69 of 85

0.00E+00

2.00E-0 3

4.00E-0 3

6.00E-0 3

8.00E-0 3

1.00E-0 2

1.20E-0 2

1.40E-0 2

1.60E-0 2

A A A A A B B B C C D

Mosaic New 

Wales

(EP-05)

CFI Plant City

(EP-stack)

Mosaic Bartow

(EP-2 )

PCS Aurora

(EP-303)

Simplot Rock 

Springs

(EP-10)

PCS Aurora

(EP-302)

Mississippi 

Phosphates

(EP-1; & 2)

Mosaic Faustina

(EP-07)

Simplot DonPocatello

(EP-1; 2; & 3)

Agrium Nu-West

(EP-6 )

PCS White Springs

(EP-32) Concentration (gr/dscf)

Hydrogen Fluoride Concentration by APF Process Line Not Reported
Page 70 of 85
Page 71 of 85

0.00E+00

1.00E-0 5

2.00E-0 5

3.00E-0 5

4.00E-0 5

5.00E-0 5

6.00E-0 5

7.00E-0 5

8.00E-0 5

9.00E-0 5

1.00E-0 4

A A A A A B B B C C D

Mosaic New 

Wales

(EP-05)

CFI Plant City

(EP-stack)

Mosaic Bartow

(EP-2 )

PCS Aurora

(EP-303)

Simplot Rock 

Springs

(EP-10)

PCS Aurora

(EP-302)

Mississippi 

Phosphates

(EP-1; & 2)

Mosaic Faustina

(EP-07)

Simplot DonPocatello

(EP-1; 2; & 3)

Agrium Nu-West

(EP-6 )

PCS White Springs

(EP-32) Concentration (gr/dscf)

Total Metals (All Data) Concentration by APF Process Line
Page 72 of 85
Page 73 of 85
Page 74 of 85
Page 75 of 85
Page 76 of 85
Page 77 of 85

Appendix E

Reported Phosphate Rock Concentration Compared 

To Reported Emissions Data
Page 78 of 85

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

0 5 0 100 150 200 250 300 Beneficiated Phosphate Rock Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

HF

APF Process Lines

PA Process Lines

SPA Process Lines
Page 79 of 85

0

5000

10000

15000

20000

25000

30000

0 5 0 100 150 200 250 300 Phosphate Ore Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

HF

APF Process Lines

PA Process Lines

SPA Process Lines
Page 80 of 85

0

500

1000

1500

2000

2500

0.00 0.10 0.20 0.30 0.40 0.50 0.60 Beneficiated Phosphate Rock Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

Total Metals

APF Process Lines

PA Process Lines

SPA Process Lines
Page 81 of 85

0

100

200

300

400

500

600

700

800

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Phosphate Ore Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

Total Metals

APF Process Lines

PA Process Lines

SPA Process Lines
Page 82 of 85

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.00E+00 5.00E-0 4 1.00E-0 3 1.50E-0 3 2.00E-0 3 2.50E-0 3 3.00E-0 3 Beneficiated Phosphate Rock Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

Mercury-30B 

APF Process Lines

PA Process Lines

SPA Process Lines
Page 83 of 85

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.00E+00 5.00E-0 4 1.00E-0 3 1.50E-0 3 2.00E-0 3 2.50E-0 3 3.00E-0 3 3.50E-0 3 4.00E-0 3 4.50E-0 3 5.00E-0 3 Phosphate Ore Concentration (ppm)

Normalized Process Line Emissions (lbs of emissions/thousand tons of P2O5)

Mercury-30B

APF Process Lines

PA Process Lines

SPA Process Lines
Page 84 of 85

Appendix F

Comparison of 2010 and 2014 Emissions Data
Page 85 of 85

COMPARISON OF 2014 DATA TO 2010 DATA FOR WPPA, SPA, AND APF PROCESS LINES

Process Line Facility Process Unit & EP

2010 2014

Notes HF 

(gr/dscf)

HF 

(lb / ton 

P2O5)

HF 

(gr/dscf)

HF 

(lb / ton 

P2O5)

Method 26A Method 320

WPPA PCS White Springs 69 (EP-69.01) 1.46E-03 5.33E-03 5.54E-04 1.45E-03

WPPA Mosaic New Wales Combined 3.58E-03 1.15E-02 1.89E-03 2.95E-03 EP-11 & EP-22

SPA Agrium Nu-West Combined 6.80E-03 9.91E-03 1.41E-01 1.99E-02 EP-522 & EP-541

SPA Simplot Rock Springs P-4 (EP-40) 5.95E-04 1.27E-03 1.08E-03 4.52E-03

APF Agrium Nu-West Gran (EP-6) 1.52E-02 2.08E-01 1.38E-03 1.43E-02

APF Mosaic New Wales P-2 (EP-05) 3.38E-03 5.92E-02 3.54E-03 5.66E-02