MEMORANDUM

TO: Tina Ndoh, OAQPS/SPPD

– Minerals and Manufacturing Group

FROM: Eastern Research Group, Inc.

DATE: August 14, 2012

SUBJECT: S ummary of August 14 , 201 2 US EPA Meeting with PCS Phosphate

1.0 Introduction

On August 14 , 2012

, the U.S. Environmental Protection Agency (EPA) met with representatives of PCS Phosphate

. The purpose of the meeting was to discuss the Risk and Technology Review (RTR) for the Phosph ate Sector. A brief summary of the visit and discussion

is outlined in Section 3 .0 below.

2.0 Attendees

Name Affiliation
John Hewson PCS Phosphate
Ross Smith PCS Phosphate
Barrie Winn PCS Phosphate
Susan Jordan PCS Phosphate Randy Taylor URS
Keith Barnett US EPA
Tina Ndoh US EPA Anne Pope US EPA
James Hirtz US EPA
Donna Lazzari ERG

3.0 Summary of Meeting

EPA gave a brief overview of the Risk and Technology Review process and the status of the review for the phosphate sector. EPA is in the process of con cluding the risk assessment. The ecological risk is still in the process of evaluation. Because the risk and technology review and any changes to the NESHAPs are on a timeline to be proposed by the end of October, and thereMemorandum US EPA Meeting with PCS Phosphate

p. 2 of 2

is an extensive review process, the re is lim ited time for industry to provide additional

information. EPA gave an overview of the process to assess the risks when a persistent bio

accumulative HAP is evaluated in a risk review. A screening process is used in order to predict what the outcome would be of a multipathway risk assessment. A multipathway risk a ssessment takes into account the amount of HAP (in this case mercury) that would be ingested if there is a lake in the vicinity of the plant, and fish from the lake were consumed. The emissions estimates for mercury from the PCS Aurora facility’s phosphat e rock calciners were presented to PCS Phosphate and it was agreed that the estimates were correct and were properly calculated from the stack tests that were submitted by PCS Phosphate

. EPA discussed the necessity to establish a MACT limit for mercury. A MACT limit was

established for phosphate rock calciners for the phosphoric acid NESHAP during the first rulemaking that used particulate matter (PM) as the surrogate for all of the metal HAP. Since PM is not an appropriate surrogate for mercury, a limit f or mercury must be established. The limit

will be evaluated as a MACT floor. Also, EPA is required to conduct a beyond

- the

- floor analysis that considers the cost and availability of emissions controls for further reducing emissions

. The group discussed the techni cal reasons why phosphate rock calciners are used at the Aurora facility and are not used elsewhere in the United States. The organic content of the phosphate ore in North Carolina is much higher than in other sources of phosphate ore. Because
of this, an oxidation process is not capable of removing all of the carbon. Carbon affects the color of the final product and must be removed for some applications. Also, in the purification

system used to produce purified phosphoric acid , the purification solvent wil l dissolve the carbon and will contaminate the solvent over time. PCS has studied other options for removing organics from the North Carolina ore but has not been successful in developing an economic or technical

alternative. PCS commented that phosphate r ock calciners are used in both Morocco and Israel. The group discussed potential methods to control mercury from phosphate rock calciners.

One method being evaluated by EPA at this time is carbon adsorption in a fixed

- bed because carbon injection along with a fabric filter was considered a less desirable option due to the high moisture content of the stack gas. PCS suggested that it may be possible to use carbon injection and capture the carbon in the currently i nstalled wet electrostatic precipitators. Also, t he majority of the mercury is present in the gaseous elemental form, and a carbon that is specific to this form of mercury must be used.