Response to Comments, APMC Stockton CoGen Draft PSD permit #SJ 85-04

September 16, 2011

EPA received three comments on the Air Products Manufacturing Corporation Stockton 

Cogeneration facility (Stockton CoGen) PSD permit, #SJ 85-04. EPA’s responses are detailed 

below: 

Commenter #1: Arthur Unger:

Mr. Unger asserted that the proposed PSD permit for the Stockton CoGen plant did not 

comply with PSD regulations and recommended that the permit not be issued. Further, he 

commented that the Ambient Air Quality Impact Report (AAQIR) associated with the Stockton 

CoGen PSD permit incorrectly allowed project netting in reaching its conclusion. 

Response to Commenter #1:

The commenter then suggests that based on an actual-to-potential test, the 

Stockton CoGen plant was subject to PSD permitting for its greenhouse gas (GHG) 

emissions. The source’s potential emissions are calculated by considering the maximum 

amount the source can emit, taking into account any federally enforceable restrictions. 

The basis of the commenter’s potential GHG emissions calculation is a continuous plant 

operating for 24 hours daily, 7 days a week. That is why the commenter calculated 

potential GHG emissions to be above the 75,000 tons per year (TPY) threshold. 

However, this level of operation is not consistent with Stockton CoGen facility’s actual 

operating conditions. 

In the AAQIR, EPA showed that the Stockton CoGen modification did not exceed 

the PSD applicability threshold for criteria pollutants. EPA conducted an actual-toprojected actual test to determine whether the modified source was subject to PSD 

regulation with respect to its GHG emissions. PSD applies if the net emissions increase 

of GHGs from the modifications is equal to or greater than 75,000 TPY on a CO2e basis 

and greater than zero TPY on a mass basis. The projected actual emissions are the 

source’s estimate of the emissions increase directly attributable to the modification. As 

stated in the AAQIR, the facility plans to rely primarily on its natural gas-fired auxiliary 

boiler; and no more than 250 hours of simultaneous operation of its coal-fired circulating 

fluidized bed (CFB) boiler and the auxiliary boiler are contemplated. The estimated 

GHG emissions from the natural gas-fired auxiliary boiler are significantly less than the 

CFB boiler GHG emissions. Under this operating scenario, the estimated emissions are 

much lower than the 75,000 TPY GHG applicability threshold. Thus, the project GHG

emissions do not exceed the PSD applicability threshold.

Although the 250 hour operations limit is a federally enforceable condition in the

Stockton CoGen Title V operating permit, an explicit condition is not included in the 

proposed PSD permit. However, EPA will include a similar condition under Permit 

Condition IX.F Operating Limitations in the final PSD permit to clarify this issue. 
Commenter #2: Rob Simpson:

Mr. Simpson submitted a comment to EPA on August 30, 2011, requesting a 30-day 

extension to the public commenting period because he allegedly was not notified of the proposed 

permit. 

Response to Commenter #2:

EPA’s records show that Mr. Simpson was notified on July 5, 2011, via electronic 

mail, of the availability of the Public Notice and related materials of the Stockton CoGen

permit. Mr. Simpson used the very same electronic mail address to submit the extension 

request. For future notifications, if Mr. Simpson prefers, EPA can arrange that public 

notices be sent to a physical address via the U.S. Postal Service. 

Additionally, the public notice clearly stated that the closing date for public 

comments was August 4, 2011. Since EPA received Mr. Simpson’s request after that 

date, the comment is not timely, and EPA is denying the request. However, there will be 

an opportunity for Mr. Simpson to comment on Stockton CoGen’s Title V operating 

permit when it is eligible for renewal. 

Commenter #3: Air Products Manufacturing Corporation: 

Stockton CoGen submitted the following administrative corrections:

Throughout the document, change the owner to “Air Products Manufacturing 

Corporation” and the facility to “APMC Stockton CoGen:”

In Section IX.B the title is missing the letter “t” at the end of “Equipment;”

Section IX.B is missing the word “SO2” in the last sentence and should read “A minimum 

SO2 removal efficiency...;”

In Section IX.F.1, first sentence, delete the word “provided;”

In Section IX.F.1.a.ii, delete the “1” at the end of “Condition IX.F.1.a.ii.1; ” and

In Section X.C the last line of the address was dropped and should include “Fresno, CA 

93726-0244.”

Response to Commenter #3:

We agree with the administrative corrections. Therefore, EPA has incorporated 

the changes in the final PSD permit.