aep 69-kv oil-insulated transmission line removal project

AEP 69-kV Oil-Insulated Transmission Line Removal Project

Michael Glueck, PE, American Electric Power Michelle Beckman, Burns & McDonnell Bill Halliburton, PG, Burns & McDonnell

Woody McOmber, PE, Burns & McDonnell C. David Slavin, EIT, Burns & McDonnell

• 2 – 800 MCM HPFF - 69 kV • 5-9/16” CS EW PIPE • 1.1 Mile Each • Somastic Coating w/ ACM

Background

Utility Locate

Splice Joints A & B • 20” x 20” Concrete

Encasement • Grounding Cables

Asbestos and Lead Sampling

Somastic Coating Containing ACM

Soil Sampling • Composite Sample

• 6” and 18” • Intern Labor

(Cheap!!!!!)

DGA Sampling - 2003 • High

Concentrations of Dissolved Gases

• Bubble Formation Due to Low Pressures

• Failure at Nueces Bay Substation

DGA Sampling-2011

• 48-Hour Circulation • Sample Pulled

Every 7 Hours

DGA Test Results - 2011

Sample Date 08/09/11 08/10/11

Sampling Point

Location 0.5qt (1:30) 0.5 qt (8:30) 0.5qt (15:30) 0.5qt (22:30) 0.5qt (5:30) 0.5qt (11:30)

Vial No. x802747042199 x802827052237 x802827062283 x802727072272 x802757082261 x802797092237 x802787102206 x802747112223 x802777122203 x802767132238 x802807142249 x802747152283

METHANE 64 59 165 154 470 455 712 687 381 374 194 185

ETHANE 12 13 27 25 159 155 132 139 110 104 71 69

ETHYLENE 2.8 3.1 29 28 180 177 162 166 121 118 74 73

ACETYLENE 0 0 0.9 1.1 1.8 2.0 1.6 1.7 1.2 1.4 0.8 0.8

PROPANE 15 17 11 12 38 41 31 38 35 36 27 30

PROPYLENE 5.4 6.7 18 22 143 148 112 116 83 84 55 58

iso-BUTANE 0.9 0.8 4.8 5.4 11 12 8 11 5.7 5.8 3.7 4.2

n-BUTANE 1.3 1.5 0.7 1.1 1.5 1.7 1.9 2.5 1.9 2.1 1.6 1.9

t-2-BUTENE 0.4 0.8 1 1 3.2 3.9 2.9 3.1 2.3 2.3 1.2 1.6

1-BUTENE 0 0 1.8 2.1 10 11 7.8 8.1 4.8 5.6 3.8 4.1

ISOBUTYLENE 2.6 2.8 28 32 124 132 93 97 59 63 37 48

HYDROGEN 723,892 689,954 1,218,944 1,159,630 208,945 203,870 1,756,565 1,029,910 708,243 717,870 171,138 166,050

C. MONOXIDE 28 22 84 69 34 32 145 95 65 52 25 21

C. DIOXIDE 147 141 143 121 146 141 136 148 171 174 156 145

OXYGEN 1,254 2,541 1,587 2,354 1,883 1,254 2,541 1,458 2,145 1,254 2,451 1,854

NITROGEN 30,748 49,800 93,847 103,054 26,096 27,560 92,816 74,646 45,716 51,390 16,309 18,780

• Cable Not Fit for Service • Hydrogen Concentrations of Gases

Disposal • Sun #6 Dielectric Mineral Oil

• 48-Hour Circulating Period

• Safety Precautions • Nitrogen? • Flammability • Water • Baker Tank with

Constant %LEL Monitoring

• 20,000-Gallon Baker Tank

• Estimated Seven-Day Pumping Time

Cable Sampling

• 12 Sampling Locations • 3 Phases per Sample • Marking the Sample • Potential PCBs and Asbestos

Cable Pulling • Two Plans

• Pipe Pigging

Device

• Winch Truck

• Preventing Spills

• Roll-off Bin

• Salvaged

Cleaning the Conduit

• Biodegradable Degreaser (Non-Hazardous)

• Temporary Pig Catcher

• Pushed with Compressed Air

Capping the Conduits

• Section of Steel Conduit Replaced and Pressure Tested

• Backfilled with Wet-able Sand & Flowable Fill

Capping the Conduits • Deep Excavations

• 10-12 feet • Valves Installed at North Shore • Gas Powered Vacuum

• Almost Near 0% Air (500 Microns)

• Filled with Nitrogen to 30 Psi

Structures to Be Demolished • Cable Terminations (Riser,

Trifurcator, Pot Heads, Spreaders, etc.)

• Pump House (Control Unit, 500-Gallon Steel Tank, etc.)

North Shore Beach • All Materials Relating to

the Existing Active Cathodic Protection System

• Transmission Pole Treated w/ Creosote

• Junction Boxes • Cable • Guy Wire

Pump House • Asbestos and

Lead Paint Abatement

Project Coordination • Client – American Electric Power

• Subcontractors and Sub-consultants

• Engineering - CH2M Hill • Engineering - PDC • CDB/Construction Management - Power Line Services • Abatement Contractor – Basic • Specialty Contractor – WA Chester • Excavation Contractor – K-West • Hydro Excavator – Hydro-Spy • Barricade Contractor – Highway Barricades • Right-of-Way and Property Ownership – ROW Services

• Governmental Agencies

• POCCA • Nueces County • City of Corpus Christi • Texas Commission on Environmental Quality

Phase II – Future Removal of Conduit Under Ship Channel

North Shore Terminals South Shore Bulkhead

Components of the Feasibility Study • Historical Document Review • Summarization of Discussions with Potential Removal

Contractors • Additional Marine Survey • Adjacent Pipeline Ownership Research • Preparation of a Limited Risk Assessment using EPA’s

BOSCEM Model • Summarization of Risks and Liabilities Associated with

the Project • Preparation of Ownership Transfer Agreement

Historical Document Review

1989 Pipeline Survey, Report on Avery Point Pipeline Survey by Shiner Mosley

and Associates (SMA, 1989)

Additional Marine Survey

2012 Pipeline Survey, Hydrographic Survey of 69-kV Transmission Line Conduit, Port of Corpus Christi, Texas by Chris Ransome &

Associates Inc. (CRA, 2012)

Anomalies

Adjacent Pipeline Ownership Research • Information obtained from Right of Way (ROW)

Services, Railroad Commission of Texas, USACE, Corpus Christi Fire Department, and National Pipeline Mapping System

• Information obtained was incomplete, contradictory, and unreliable

• At least 50 other pipelines that exist in the Inner Harbor portion of the Ship Channel may also have to be removed or deepened

Limited Risk Assessment using EPA’s Risk Model (BOSCEM)

Three Plausible Scenarios:

• Low Risk Scenario – Damaging and causing an oil release from the pipeline nearest (within 1.5 feet) to AEP conduits.

• Less Likely Scenario – Damaging and causing an oil release from the four pipelines nearest (within 8 feet) to AEP conduits.

• Least Likely Scenario – Damaging and causing an oil release from the five pipelines nearest (within 11 feet) to AEP conduits, which includes the largest diameter pipeline (30-inch) in the corridor.

Model incorporates specific factors such as: • Calculated Spill Volume • Oil Type • Cleanup Techniques and Effectiveness • Impacted Medium • Location-specific Socioeconomic Value • Freshwater Vulnerability • Habitat/wildlife Sensitivity • Location Type

Using the Model to calculate the cost estimates, the resulting calculations

for each scenario described are as follows:

Scenario: Estimated Total Cost:

Low-risk case $8 Million

Less likely case $40 Million

Least likely case $167 Million

Summarization of Risk and Liabilities Associated with the Project

• Safety of Divers • Damage to Adjacent Pipelines • Airborne Release of ACM • Stability of North and South Banks • Interruption of Ship Channel Traffic • All Inherent Risks

Feasibility Study Conclusions • Estimated removal costs: $1.1 million to $2.5 million, which only

includes removal costs and does not include costs for AEP’s time, permitting, oversight, or additional consultation, etc.

• Estimated cost of associated risk: $8 million to $167 million • AEP conduits do not currently pose risk to the other pipelines,

the public, or POCCA • AEP’s conduits’ presence in the ship channel does not impede

plans to move forward with the channel deepening project any more than any of the other pipelines.

• It’s in the best interests of POCCA, the community, and AEP to remove AEP’s conduits after the removal of the adjacent lines.

Summary • Environmental Sampling • Removal of Cable and Insulating Fluid • Demolition of Aboveground Structures • Ownership Transfer of Conduit • Evaluation of the Feasibility of the Removal of Conduit under the Ship

Channel • Completed with Adherence to Federal, State, and Local Regulations • Approximately 10,000 Man Hours Worked with Zero OSHA Recordables

Questions?