Critical Infrastructure: Dyke Infrastructure Modification

Modifying the electrical and communication infrastructure of a tailings pond to allow for expansion.

Situation

Dyke tailing ponds act as temporary storage for byproducts from oil production, like sand, clay, water, and bitumen.[1] To avoid environmental mishaps, processing plants are required to keep tailings at least 3 meters below the surface.1

An oil and gas processing facility’s tailing pond kept filling to the freeboard level (2 meters below the surface). This was introducing stress due to environmental concerns and inefficiencies to plant processes. This introduced add-work of monitoring the level and relocating the excess frequently.

A construction company was commissioned as the prime contractor to expand the tailing pond capacity to mitigate this. However, increasing the pond capacity was not all that was required. As part of the reclamation process, industrial facilities use barges fitted with pumps and siphons that decant water and recycle it for other uses at the plant.[2] The tailings pond had E-houses containing switch gear and automation cabinets that needed to be moved for the pond expansion. Due to the electrical and automation functionality of this infrastructure, the prime contractor needed an experienced and adept Operational Technology (OT) integrator to do the job.

Why InnoTech?

The InnoTech team had helped previously relocate barges and e-houses for a similar project, and along with the trust developed with the client, InnoTech was the only team for the job.

Actions taken

The team disconnected and relocated the existing buildings (including all the substations, e-houses, and barges) to the new higher elevation. To address unreliability, the team redesigned the grounding system for certain buildings. The team revised the power calculations for the power system and re-engineered the cable connections to ensure the relocated equipment and buildings could function at the new elevation.

Challenges

Some roadblocks that occurred during this project included:

• Unclear direction: Defining the new locations and elevations for the buildings happened much later in the project.
• Incorrect As-builts: The Arc flash and power system model studies did not account for the former e-house and barge move.
• Stop and start: The client needed extensive time for their decision making, which put the project on hold sporadically. To minimize the rework that could result from this, the project team kept comprehensive notes to ensure they could start from where they left off each time.

Results

The client now has:

• An additional 8-10 meters of capacity in their tailings pond.
• An extended lifespan of approximately 20 years.
• Reduced risk in their grounding system.
• Reliable and up to date As-built, Arc flash, and Power Systems study drawings.

Discussion Questions:

How are you planning for future updates and enhancements before they become a critical need? And do you map out the implementation processes before starting work?

[1] Oil Sands Magazine. (2021, March 3). Tailings ponds 101. Oil Sands Magazine. https://www.oilsandsmagazine.com/technical/mining/tailings-ponds

[2] Vick, S. G. (1990). Planning, design, and analysis of tailings dams. https://damfailures.org/wp-content/uploads/2022/01/Vick_Steven_Planning_Design_Analysis_Tailings_Dams_1990-1.pdf