TO: Tina Ndoh and Keith Barnett, EPA

FROM: ERG

DATE: February 2, 2015

SUBJECT Notes from meeting between EPA and PCS Aurora

Summary:

A meeting was held at EPA-RTP to discuss PCS Aurora’s unique gypsum stack rotation 

operations and management system, and how the proposed definitions (i.e., ‘closed 

gypsum dewatering stack’ versus ‘active gypsum dewatering stack’; and ‘new source’ vs. 

‘existing source’) and requirements in the proposed rule may apply to the system.

Names of participants:

• Tina Ndoh – EPA/OAQPS

• Keith Barnett – EPA/OAQPS

• Tom Walton – EPA/OAQPS

• Ann Johnson – EPA/OP

• Terrence Lee Baker – PCS Aurora

• Susan M. Jordan – PCS Aurora

• Ross M. Smith – PCS Aurora

• Judith Ann George – PCS Aurora (internal council for PCS Aurora)

• Charles T. Wehland – Jones Day (external council for PCS Aurora)

• Jason Renzaglia – ERG

Topics of discussion:

1. EPA and PCS Aurora discussed matters regarding their unique gypsum stack rotation 

operations and management system. These matters were previously addressed in PCS 

Aurora’s comments which are included in the docket, except for the following:

• Details of the functionality related to PCS Aurora’s gypsum stack rotation 

operations and management system was discussed, including how the system

interacts with their mine pit.

• Characteristics of the PCS Aurora mine were discussed, including how it is 

unique to other phosphate ore mines. The PCS Aurora facility has been issued a 

mine permit that requires gypsum reclamation.

• An aerial photo was provided by PCS that illustrates the gypsum stacks at PCS 

Aurora facility (refer to page 3 below). The aerial photo shows gypsum stacks #4, 

#5, #6 make up PCS Aurora’s gypsum stack rotation operations and management 

system. The status of PCS Aurora’s gypsum stacks as depicted in their aerial 

photo is as follows:

o Gypsum Stack #6 – receiving gypsum

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o Gypsum Stack #5 – supplying gypsum for mine reclamation

o Gypsum Stack #4 – in process of being dewatered

• PCS Aurora pointed out that they are concerned about triggering the proposed 

regulation for a ‘new source’ each time they rotate the functionality of their three

gypsum stack sites. For example, PCS Aurora is currently in the process of 

rotating their stacks such that Gypsum Stack #5 would be the receiving, Gypsum 

Stack #6 dewatering, and Gypsum Stack #4 supplying gypsum for mine 

reclamation. During this rotation, the company is concerned that Gypsum Stack 

#5 would be considered a ‘new source’, which would trigger the ratio requirement 

under the proposed rule.

• Two potential options were discussed that could allow for gypsum dewatering 

stack sites to be used for reclamation and not trigger the proposed requirements 

for a “new” gypsum dewatering stack:

o PCS Aurora confirmed that the location and size of the footprint for each 

gypsum stack in their rotation operations and management system does

not change. The proposed definition of “existing” gypsum dewatering 

stack could be revised to incorporate the concept of existing 

acreage/footprint.

o PCS Aurora confirmed that they would be required to obtain a permit to 

construct a new gypsum stack. The proposed definition of “new” gypsum 

dewatering stack could be revised to include permitting language so that 

any existing permitted gypsum dewatering stack could not trigger “new”. 

2. EPA discussed the process it uses for addressing comments.

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