# E C 

# / R Incorporated Providing Environmental Technical Support Since 1989

501 Eastowne Drive, Suite 25 0  Chapel Hill, North Carolina 2751 4 Telephone: (919)484

- 0222  Fax: (919) 484

- 0122 MEMORANDUM

Date: May 28, 2010

Subject: Site visit report for the PSNC Energy Compressor Station in Ruffin, N.C.

From: Robert Vogt, EC/R Incorporated

Phil Norwood, EC/R Incorporated

To: Bruce Moore, EPA/OAQPS/SPPD/CCG

I. INTRODUCTION

The purpose of t his memorandum is to summarize the Environmental Protection Agency (EPA) site visit to the Public Service Company of N.C. (PSNC) compressor station in Ruffin,

North Carolina.

II. LOCATION AND DATE

PSNC Energy

– Ruffin Field Station Ruffin, North Carolin a

February 2 3 , 2010

III. ATTENDEES

PSNC David Knott, Supervisor, Transmission & Compression , Durham Region Douglas G. Hobson, AECOM Environmental Project Manager

Robert T. Sievers, Manager, Engineering, System Design

Tucke r Bullock, Manager, Operations, Durham Region

U.S. Environmental Protection Agency (EPA)

Alex MacPherson

Bruce Moore

David Salman

Jodi Howard

Nick Parsons Rachel Agnew

EC/R Incorporated

Heather Brown

Phil Norwood Robert VogtIV. OVERVIEW OF SITE VISIT

The purpose of this visit was t o gather information about the PSNC facility and its processes, with a focus on the air emissions and equipment, practices and controls that reduce these emissions. Prior to the visit, EPA mailed PSNC a letter 1 which included an outline of

information of interest for the site visit. During the site visit, PSNC provided the EPA with information in response to this outline (See Attachment 1 ).

Upon arrival at the site, Mr. Moore provided a summary of the purpose of the visit and

introductions were made. Thi s was followed by a tour of the facility led by Mr. Sievers. During this tour, p hotographs were taken of facility equipmen t . These photographs are included a s Attachment 2

.

V. SITE AND PROCESSES

PSNC is a wholly owned subsidiary of Scana Energy. The PNSC Ruffin station is a natural gas compressor station. It is one of several compressor stations along the pipeline between the transcontinental pipeline and the natural gas customers in the Raleigh

- Durham,

North Carolina area. The station, which is an unmanned facility controlled from the PSNC office in Gastonia, North Carolina

, ope rates on a seasonal basis.

The PNSC Ruffin station began operations in the early 1960s , and originally housed two 1200 horsepower natural gas

- fired compressor turbines. The facility was renovated between 2008 and 2009, and the existing compressor turbines were replaced with two electric

- start,
Saturn 20

- 1600 natural gas

- fired turbines with a nominal power rating of 1425 hp and a heat input of 17.45 MMBtu/hr each.

V I

. EMISS ION SOURCES, PERMITS, AND REGULATIONS

Air pollutants generated by this facility include PM, NO

x , VOC, CO, SO 2 , and HAPs.

D etailed emissions data and permit conditions for this facility can be found in the attached North Carolina Department of Environmen t and Natural Resources ( NCDE N R ) Air Quality Permit ( see Attachment 3 ). T wo natural gas

- fired compressor turbines are the most significant emissions

sources from thi s facility. Both turbines C3 and C4 are subject to NSPS subpart KKKK

, Standards of Perfor mance for Stationary Combustion Turbines

. This NSPS covers emissions of

NOx and SO 2

.

These turbines have an emission limit of 0.060 lb SO 2 per million Btu. This standard is met by ensuring that fuel for the turbines meets specified fuel quality chara cteristics , which is

verified via tariff sheets.

These turbines have a NO

x emission l imit of 100 ppm at 15% O 2

. Compressor C 3 was tested in July 2008 and had a NO

x emission rate of 43.83 ppm, and compressor C4 was tested in January 2009 and had a NO

x em ission rate of 73.73 ppm. The facility has no applicable

1 Letter from Hustvedt, Kent C., Coatings and Chemicals Group, Office of Air Quality Planning and Standards, United States Environmental Protection Agency, Research Triangle Park, NC, to Sievers, Robert, Public Service Company of North Carolina, Gastonia, NC. Confirmation of Site Visit. February 17, 2010.emissions limits on CO and PM. The facility does not maintain an integrated LDAR (Leak

Detection and Repair) program for VOC emissions reduction.

In addition to compressor turbines, a 2 8 0 kW natur al gas

- fired emergency generator is

located at the facility (Emissions source ID: E

- 1)

. This generator is subject to the requirements

under NSPS subpart JJJJ. The unit was installed prior to January 1 , 2009 and is not subject to NSPS subpart ZZZZ. The gen er ator is operated once per month on a testing basis.

Insignificant/unpermitted air emissions sources at this facility include compressor station

blow downs at shutdown , and a 250,000 Btu/hr natural gas

- fired heater used to preheat natural gas fuel enteri ng the combustion turbine

. This small gas heater is not listed in the permit. Methane is the primary pollutant emitted by these source s

.

In addition to the routine process operations and emissions, startup and shutdown events

were also discussed. The fa cility logged 40 shutdowns of compressor C

- 3 and 35 shutdowns of compressor C

- 4 over a twelve month period prior to the site visit. PSNC maintains a log of start

up and shutdown events. PSNC staff reported that equipment malfun ctions were rare, and were typically isolated to fail

- to

- start malfunctions.

Note: Following the visit, Mr. Sievers confirmed that there was no information discussed during the visit that PSNC considered confidential business information (CBI). A copy of this email confirmation is included as Attachment 4.