To Parallel or Not to Parallel, That Is the Question

A few decades ago, linear infrastructure crisscrossed the American landscape in straight-line routes with little consideration for other existing easements. Occasional crossings occurred, but parallel siting was uncommon because open land was so prevalent.

Today, although the demand for energy infrastructure continues to grow, siting for linear utilities such as transmission lines and pipelines has become more complex as available, undeveloped land becomes scarcer. In addition, the public has become more involved and vocal about preserving natural resources and protecting the environment.

This dilemma requires a more creative siting approach—one in which limited space is used and potential impacts to affected resources are minimized. One of these approaches is paralleling easements with existing infrastructure (or paralleling, for short). Paralleling can incorporate electrical transmission lines, distribution lines, roadways, abandoned and active railways, pipelines, fence lines and even apparent property boundaries.

There are a number of benefits and challenges to consider before determining whether paralleling is the best option for your next siting project.

What Are the Benefits?

One of the most compelling benefits to paralleling existing infrastructure is that it minimizes impacts on sensitive environments and natural resources. New disturbances are avoided, and habitat fragmentation is minimized by abutting easements.

In addition, regulatory agencies tend to view paralleling as beneficial. In fact, in accordance with the Energy Policy Act of 2005, the Bureau of Land Management (BLM) designated 5,000 miles of energy corridors (commonly referred to as “Section 368 energy corridors” or “West-wide energy corridors”) for potential placement of future oil, gas and hydrogen pipelines as well as electric transmission and distribution infrastructure. These designated corridors help reduce the number of greenfield projects located on BLM land.

Generally, it is assumed that greenfield projects may have greater potential impacts on resources such as threatened and endangered species, wetlands or cultural resources. When paralleling a project with an existing easement, however, it will likely have similar impacts to the existing easement, keeping new disturbances to a minimum.

Similar to regulatory agencies, non-government organizations such as the Sierra Club consider parallel routing to be less invasive as compared to a greenfield project. In their Energy Facility Siting Guidelines, the Sierra Club states, “The development of new electric transmission line corridors, as a general principle, should be kept to an absolute minimum. To that end, new transmission lines should, whenever possible, utilize corridors already established for highways, railroads, and pipelines, and/or share previously established electric transmission corridors.”

Construction next to an existing easement may also have benefits. While it may vary from project to project, construction access may be easier with existing, adjacent easements and developed access points or roads. Similarly, some utilities may be able to reduce right-of-way clearing and grading requirements by overlapping existing easement areas.

What Are the Challenges?

Despite best efforts, not all infrastructure is compatible. An electric transmission line, for example, can potentially interfere with the integrity of an oil or gas pipeline when paralleled too closely. Without adequate cathodic protection, the close proximity of a new transmission line can cause the pipeline to corrode. Paralleling incompatible easements can be a major concern for project designers and has the potential to cost the project more than it saves.

Reliability and safety concerns may also preclude paralleling an existing easement. For instance, although transmission lines are typically compatible with other transmission lines, for reliability reasons, electric utility companies do not parallel their own transmission lines for long distances.

Similarly, pipelines have their own minimum offset requirements, both above- and below-ground, to ensure maintenance such as repairs and excavations can be performed safely. And in the presence of a nearby above- and/or below-ground utility line, there are limitations on where construction activities can occur. Additional safety measures must be taken to ensure construction equipment does not come into contact with the existing infrastructure. If spacing between the various infrastructure easements is not adequate, paralleling may not be possible.

Additional constraints like habitable structures, cultural resources and sensitive wetlands near existing infrastructure should also be closely examined. Even if open land is available, if the new infrastructure impacts the surrounding area in ways the previous infrastructure avoided, then paralleling may not be the best option.

Not all parallel infrastructure projects have favorable operational arrangements with adjacent utilities. Project developers must research and coordinate operational and maintenance agreements with adjacent utilities. Sometimes a mutually beneficial agreement cannot be arranged, taking the option of paralleling off the table.  

Another aspect to consider is if there are no existing easements in close proximity to the project. Carefully consider whether it makes sense to route your project an additional 10 miles simply to parallel existing infrastructure.

Construction adjacent to existing infrastructure can also pose constructability challenges. In areas with multiple easements, the infrastructure installed first typically selects the most desirable route (e.g., favorable terrain, limited resource crossings, easy access). In these circumstances, subsequent parallel infrastructure projects are usually relegated to less desirable routes—making constructability a potentially insurmountable challenge.

What’s the Bottom Line?

Deciding whether or not to parallel existing easements is not a simple decision to make. While the benefits could be great, it is always worth researching to determine the context and feasibility of each project on a case-by-case basis. Minimizing environmental impacts continues to be a compelling motivator: it helps ensure regulatory compliance, improves public acceptance and increases sustainability.

However, when deciding whether to parallel or not to parallel, keep in mind that paralleling is not always the best option. Carefully weigh each factor to arrive at the best decision for an optimal long-term project outcome.

Article originally published in the Fall 2020 issue of Currents. Subscribe today to stay current on environmental insights and regulatory updates that impact your projects.