**Anadarko Petroleum Corporation** OCS Air Permit Application for Drilling, Exploration, and Maintenance Activities in the EGOM EPA’s Incompleteness Determination Letter Dated February 27, 2013

Trinity Consultants Page 1 of 3 **Additional Information Regarding Comment No.**  **2**

2. The BACT analyses for diesel engines in section 5 of the application identified Replacement of Older Engines with Newer Engines and EPA Tier 2 Standards as available control technologies. The Replacement of Older Engines with Newer Engines should identify the cleanest engines that are currently available; this may be EPA Tier 2, EPA Tier 3 compliant engines, or another cleaner engine. The BACT analyses for the diesel engines, (specifically DR

- GE

- 07, DR

- GE

- 08, DR

- AC

- 01, DR

- AC

- 02, third party engines, and SV

- PE

- 01 through SV

- PE

- 08), should identify what the cleanest engines are for each applicable unit, and the use of cleanest available engine in the top

down BACT analyses. **Anadarko Response** : Anadarko respo nded to EPA’s comments regarding BACT for DR

- GE

- 07, DR

- AC

01, DR

- AC

- 02, and SV

- PE

- 01 through SV

- PE

- 08 in the response letter submitted on March 27, 2013. This letter provides a response to EPA’s Best Available Control Technology ( BACT ) comments regarding third party engines, t he water blasting engine , and the Remotely Operated Vehicle ( ROV ) emergency g enerator

. **Third P**  **arty Engines**
The t hird party engines do not permanently reside on the drillship. These engines will be leased and brought onboard when they are needed for use and then removed . BACT for the third p arty e ngines (DR

- WL

- 01, DR

- WL

- 02, DR

- EL

- 01, DR

- EL

- 02, DR

- CU

- 01, DR

- CU

- 02, DR

- WC

- 01 through DR

- WC

- 04, DR

- WC

- 07, and DR

- WC

- 08) has been qualitatively determined as compliance with 40 CFR 89 Tier 2 Standard and low NO x engine ( LNE ) design. It is important to note that these t hird party e ngines need to go through several certification pathways before being employed on the drillship

. The certifications could include approval from several authorities such as International Maritime Organization ( IMO ) , Lloyd’s Register (LR), Det No rske Veritas (DNV), Germanischer Lloyd (GL), American Buraeau of Shipping (ABS), and /or Nippon Kaiji Kyokai (NK). These certification requirements could take significant time to accomplish. Anadarko contacted two vendors for each third party engine category to gather information regarding the inventory and identify cleanest available engine for each category of the third party equipment

. The vendors contacted have been utilized in the past b y Anadarko to lease similar third party engines

. The Table below summarizes Anadarko’s findings regarding the cleanest available engine in the vendors’ inventory for each category of third party engines

. The engines complying with all necessary certificat ions (i.e., eng ines ready to be used onboard) are included in the Table below.



### EPN **Third Party IC Engine Equipment**  **Type Cleanest**  **Available Engine in the**  **Category Anadarko**  **Proposed BACT**  **% of inventory if the**  **Cleanest Available Engine is Tier III or Tier IV**  DR

- WC

- 01 Tubing Running Tier II Tier II Not Applicable

DR

- WC

- 02 Fluid Filtration Pump Tier IV Tier II ~5%
DR

- WC

- 04 Slickline Power Pack Tier III Tier II ~15%**Anadarko Petroleum Corporation** OCS Air Permit Application for Drilling, Exploration, and Maintenance Activities in the EGOM EPA’s Incompleteness Determination Letter Dated February 27, 2013

Trinity Consultants Page 2 of 3 

### EPN **Third Party IC Engine Equipment**  **Type Cleanest**  **Available Engine in the**  **Category Anadarko**  **Proposed BACT**  **% of inventory if the**  **Cleanest Available Engine is Tier III or Tier IV**  DR

- WC

- 07 CT Power Pack Tier II Tier II Not Applicable DR

- WC

- 08 CT Pump Tier II Tier II Not Applicable DR

- EL

- 01, DR

EL

- 02, and DR

- WC

- 03 Eline Power Pack Tier III Tier II ~9%

DR

- WL

- 01 and DR

- WL

- 02 Wireline Tier III Tier II ~20% DR

- CU

- 01 and DR

- CU

- 02 Casing Unit Tier II Tier II Not Applicable

As shown in the Table above, EPA Tier II certified engine s w ere found to be the cleanest available engine for the Tubing Running engine, CT P ower Pack engine, CT Pump engine, and Casing Unit engine categories based on Anadarko’s survey. Anadarko proposed to meet the BACT requirements for these engines by the use of EPA Tier II certified engine s , which is the cleanest available engine for these third party engine categories

. For the Fluid Filtration Pump engine , Slickline Power Pack engine, Eline Power Pack engine , and Wireline engine, the cleanest available engine was found to be EPA Tier III or Tier IV certified. However, upon further investigation, the vendors noted that EPA Tier III and Tier IV certified engines constitute a small percentage (i.e., appr oximately less than 20%) of the total inventory.
Due to constantly changing schedul e s during the proposed operations, the availability of t hese third party engines change s on short notice. Hence, it is difficult to determine which specific engine would b e brought onboard on any given day . Since availability of the EPA Tier III and Tier IV engines is limited, there is no guarantee that these engines will be available when Anadarko would need them. Restricting these third party engines to EPA Tier III or Tier IV certified engines will significantly impact the operations

. Since EPA Tier II certified engines are more readily available for these engine categories , Anadarko proposes the use of EPA Tier II certified engine s for the Fluid Filtration Pump engine, Slickline Power Pack engine, Eline Power Pack engine , and Wireline engine categories to meet BACT requirements. **Water Blasting Engine (DR**

**- WB** 
**- 01)** 
EPA requested identifying the cleanest available engine in this category as well as a cost of replaceme nt of this engine with the cleanest available engine

. EPA Tier III certified engine is the cleanest available engine in this category based on the information Anadarko gathered. Anadarko proposed use of an EPA Tier II certified engine to meet the BACT requirements for this engine in the submitted application. However, Anadarko would like to update the proposed BACT for this engine to reflect the recent changes. F or this applicat ion , Anadarko proposes use of an EPA Tier II I certified engine to meet the BACT requirements for this engine.**Anadarko Petroleum Corporation** OCS Air Permit Application for Drilling, Exploration, and Maintenance Activities in the EGOM EPA’s Incompleteness Determination Letter Dated February 27, 2013

Trinity Consultants Page 3 of 3 **DR**
**- GE** 
**- 08** 

**– ROV Emergency Generator** 
DR

- GE

- 08 is an EPA Tier 2 certified Remotely Operated Vehicle (ROV) emergency generator

. I t operates intermittently during non emergency situations primarily for maintenance and testing . The proposed operating time for this engine is 1 hr/day and 100 hrs/yr. Given the engine’s minimal operating time, emissions are minimal. For example, the NO X emissions are 0.22 tons tpy. Therefore, Anadarko believed detailed cost infeasibility was not warranted. EPA agreed that a comprehensive cost infeasibility analysis is not required for this equipment; however, EPA requested Anadarko to identify the cleanest available engine in that category and provide a cost of replacement of this engine with the cleanest available engine. Accordingly, Anadarko contacted the engine vendor (i.e. Cummins, Inc.) and confirmed that an engine complying with EPA Tier II standards is the cleanest available engine in this category. Hence, Anadarko proposes the use of an EPA Tier II certified engine to meet the BACT requirements. **Additional Information Regarding Comment No. 6** 
6. Please confirm that there are no welding act ivities that will generate emissions on the OCS
source. If welding activities do occur, the emissions should be accounted for in the emission calculations and in any other applicable sections in the application. **Anadarko Response :**  The welding operations will be performed as a part of maintenance activities. The proposed welding operations will result in minimal increase in short term and long term emissions of PM, PM 10 , PM 2.5 , and HAPs. Moreover , Anadarko would like to add Vertic al Seismic Profile (VSP) engines as additional sources of air pollution and increase operational flexibility of certain air pollution sources, such as the water blasting engine (DR

- WB

- 01) and Emergency Generator engine (DR

- GE

- 07) , by increasing currently r equested operating time. Due to the changes indicated above, the revised Potential to Emit (PTE) of a few pollutants (e.g., PM 10 ) will be greater than the emission rates used for performing a ir dispersion modeling analysis for respective pollutants. Hen ce, Anadarko will submit a permit application addendum including emission calculations for requested changes, revised air dispersion modeling analysis, and other relevant PSD/Title V application package contents in four to six weeks.