Last Word: Sustainable and Resilient Construction and Infrastructure Management
Sustainable design and construction has gained significant momentum in the past few decades due to the wide ranging economic, environmental and social benefits it provides to project owners. Since the early 1990s, thousands upon thousands of construction projects have been certified as green based on their design, construction and operation.
There are certification agencies in nearly every major country across the globe and the green building movement seems to be gaining in popularity. To-date, most of the green construction focus has been on building construction, but there are numerous infrastructure projects that can also qualify as green and sustainable projects, including pipeline infrastructure. Many engineers know this as the triple-bottom line approach that accounts for not only direct costs, but also environmental and social benefits of infrastructure constriction and management. The use of trenchless technologies is a great way to achieve a solid triple-bottom line and help owners to manage their infrastructure in a sustainable manner.
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The first pillar of sustainability is economic, which has historically been the sole driver for all types of construction until recently. The drivers for economics are well understood and in regards to pipeline construction is primarily driven by the availability of qualified contractors and availability of competitive technologies in the marketplace, which tend to drive down costs. For trenchless technologies, some markets are well established and have many competing technologies and contractors in the space. For example, cured-in-place pipe (CIPP) technology for the gravity market is coming up on 50 years in our industry and is a well-established repair tool for all sizes of cities.
For this reason, the costs are very competitive and in most cases the economics favor CIPP over traditional pipe repair methods. There are also newer trenchless techniques —as our industry is one of the more innovative in the construction space — and although these technologies may offer other benefits as discussed below, it typically takes some time before the technology is cost-effective without accounting for social and environmental benefits as well.
The second pillar of sustainability is environmental, which can have multiple meanings when applying it to pipeline infrastructure projects. First, and most directly, many times wastewater repair works are undertaken to either address or prevent environmental contamination from sewer breaks or overflows. Also, drinking water pipeline projects are sometimes undertaken to improve water quality, which can help to improve public health in some cases. Trenchless methods are commonly used to address these types of issues with the direct benefit of reducing potential contamination events.
Environmental sustainability also relates to the nature of the materials being used on a project, their durability, and also the recycling or reuse of materials when possible. Many of the materials used in the trenchless industry are designed to be durable for long life-cycles, typically 50 years, which reduces the need make repairs. This also helps limit the strain on resources, which helps to sustain those raw materials for future generations.
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The third, and final, pillar of sustainability is social, which is a widely publicized benefit of trenchless technology over traditional pipeline infrastructure management methods. I personally could write a thesis on the social benefits of trenchless technology, and have already. Most notable of the social benefits of trenchless technology is the greatly reduced traffic delays due to the limited footprints of trenchless project setups. Numerous studies have been conducted on this topic and regularly show that the delays to travelers, both in vehicles and pedestrians, will typically account for costs well above the direct costs of the pipeline construction itself. That does not even include the costs to businesses which see losses when highly disruptive projects take place near their businesses.
In addition to traffic delays, other social costs that are minimized when using trenchless methods versus traditional methods include lower vehicle operating costs to travelers, less noise and dust pollution, better trench safety, and increased road surface values to name a few.
When it comes to certifying projects as green and sustainable, many engineering professionals are familiar with the LEED system, which is used for building projects. There are however other systems for certifying infrastructure type projects, specifically the Envision system that was developed by the Institute for Sustainable Infrastructure (ISI). Envision aims to foster a dramatic and necessary improvement in the performance and resilience of our physical infrastructure. Projects can be certified all the way up to Envision Platinum if it achieves 50 percent or more points from the 14 subcategories used for rating projects.
Some studies already exist that show projects which use trenchless methods for repairs and assessment greatly increase the sustainability of pipeline projects over their life time. As the focus of project owners continue to move towards sustainable design and construction, the benefits of trenchless technology will continue to rise above traditional methods for both construction and infrastructure management.
Dr. John C. Matthews is the director of the Trenchless Technology Center (TTC) at Louisiana Tech University.