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Integrity Management

MPL utilizes comprehensive risk-based integrity management practices to ensure the safety of the facilities and pipelines we operate, with additional emphasis where a release from a pipeline could affect a densely populated area, drinking water, ecological areas, or a commercially navigable waterway. These practices address various threats that could affect the pipelines, including excavator damage, corrosion, operator error, and equipment failure. Routine processes and procedures are employed to maintain the integrity of the pipelines including qualified personnel, sound construction practices, and proactive inspection and maintenance programs.

Operator Qualification Program

Our Operator Qualification Program complies with the requirements of the U.S. Department of Transportation's regulations found in 49 CFR Part 195, Subpart G and 49 CFR Part 192, Subpart N. The program contains guidelines and procedures designed to ensure that all individuals performing operations and maintenance work on MPL's DOT-regulated assets are qualified to perform specific covered tasks. The intent of this program is to reduce the risk of incidents occurring from human error.

Design and Construction Standards

We design and build pipelines to meet or exceed the pipeline construction requirements provided by the Department of Transportation (DOT), Pipeline and Hazardous Material Safety Administration (PHMSA), American Society of Mechanical Engineers (ASME), American Petroleum Institute (API), and others.

Our pipeline construction process involves route selection, regulatory permitting, design, material selection, site preparation, pipeline stringing, trenching, bending, welding, coating, lowering and backfilling, inspection, testing, and site restoration. Our internal standards provide detailed guidelines for each step in the construction process. We use rigorous inspection and quality control procedures to ensure assets are built to operate safely.

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Stage 1: Survey and Pre-Construction

  • Crews begin by surveying the potential route, evaluating ways to minimize ecological and geological impacts.
  • Narrow strips of land called rights of way are acquired for installation of the pipeline and to host on-site construction activity.

Stage 2: Clearing

  • The right of way is cleared of trees, brush and rock.
  • Topsoil is stockpiled for eventual reclamation.
  • The right of way is leveled and graded to provide access for construction equipment.

Stage 3: Trenching

  • A trench is dug with a trencher or excavator.
  • In some areas, the pipe is installed with a trenchless process by boring under waterways, roads or railroads.

Stage 4: Pipe Stringing

  • Individual pieces of pipe are laid out end to end along the right of way.
  • The pipe is bent to fit the terrain using a specialized hydraulic bending machine.

Stage 5: Welding and Pipe Inspection

  • Welders join the pipes together using both manual and automated welding technologies.
  • The welds are then inspected and certified by x-ray or ultrasonics.
  • Protective pipe coating is applied across the welds and inspected for quality assurance.

Stage 6: Lowering Pipe and Backfilling

  • The welded pipe is carefully placed into the trench using heavy equipment and is buried at a minimum depth of four feet.
  • Valves and other fittings are installed on the pipe.
  • The pipe is padded using filtered native soil to keep rock and other impediments from resting along the pipe.
  • Topsoil is replaced in the sequence in which it was removed and the land is re-contoured.

Stage 7: Testing

  • The pipeline is pressure tested using water, and inspection tools are sent through the pipelineto ensure integrity.

Stage 8: Restoration

  • Temporary facilities are removed.
  • All impacted land is reseeded for restoration.

Equipment Inspections and Maintenance

Detailed programs have been developed to ensure equipment in our facilities and along our pipelines operate safely. We complete periodic inspection, testing and preventative maintenance on meters, block valves, pressure relief valves, communication devices and other pipeline equipment to ensure it is of sound integrity and is functioning properly. When necessary, repairs are made to maintain safe operations and additional risk mitigations are implemented.

Cathodic Protection

MPL cathodic protection systems consist of rectifiers and ground beds that send a small electric current through the soil and water to help protect the pipeline from external corrosion. Each year we complete thousands of cathodic protection inspections to ensure our systems are functioning properly and adequately protecting our assets. We capture rectifier and critical bond readings bi-monthly, and complete full cathodic protection surveys of every pipeline annually. Projects and maintenance tasks are scheduled to correct any deficiencies discovered during the surveys.

Damage Prevention and Public Awareness

Any digging activities around underground utilities, including pipelines, could be dangerous. That's why we have made it our focus to support education of the national 811 Call Before You Dig program. With a free call to 811 or a click on, you can (ask - request - schedule) to have your underground utility lines located, preventing accidental damage during excavation, landscaping or any other outdoor project.

Right-of-Way Clearing and Inspection

We perform right-of-way clearing for one reason ‒ public safety. A clear right of way provides an increased ability to visually monitor threats to the pipeline. Right-of-way clearing enables:

  • Aerial Surveillance - Aerial patrols of our rights of way are completed on a weekly basis to detect active or potential excavation activities along the pipeline and visually assure no releases have occurred.
  • Excavation Damage Prevention - A clear pathway provides a visual corridor so the pipeline can be defended from unauthorized excavation and development.
  • Clear Access - Clear access to the pipeline is critical to completing required inspection and maintenance in a safe, efficient and effective manner. It also allows for prompt response in the event of an emergency.
  • Corrosion Protection - Tree roots can wrap around a pipeline, damaging the protective coating of the pipeline. This damage compromises efforts to prevent pipeline corrosion.

Internal Inspections

We have a comprehensive program for monitoring the safety of our pipelines. Multiple inspection tools are used to assess pipeline integrity, including in-line inspection tools or "smart pigs" that perform various maintenance operations on the pipeline. In-line inspection tools travel inside pipelines scanning the walls with technology similar to an ultrasound or an MRI in a doctor's office. These tools scan the entire pipe surface to identify corrosion, dents, cracks and land movement. The information is evaluated by engineers, then field inspection and repair are completed if necessary. Regulated pipelines are inspected at least once every five years.

We also use similar technologies to scan tank floors, walls and roofs to assure continued safe operation. Various coating technologies are used to protect the inside of the tanks. Regulated tanks are inspected at least once every 20 years.

Waterway Crossing Inspections

Waterway crossing inspections are performed to examine pipelines under some streams, rivers and lakes. Divers complete underwater inspection and use specialized equipment to determine the depth of cover above the pipeline. Information is used to help determine which pipelines are prone to erosion and water channel changes. Depth of cover above the pipeline is also monitored at other locations on the pipeline such as in tillable fields.

Hydrostatic Testing

Hydrotest inspections allow us to test the integrity of the pipelines we operate under environmentally safe conditions. During a hydrotest inspection, a portion of the pipeline is filled with water. Pumps are then utilized to increase pressure to test the pipeline for a specific period of time.