By Laura Harvey, Managing Editor, Utility
When it comes to trenchless technologies, most utilities are aware of the core benefits these innovative options offer, but the subtle benefits can sometimes be forgotten. Here, we take a closer look at the triple bottom line benefits trenchless technologies can offer to utilities.
Trenchless technologies arrived in the Australian utility market place in the 1980s, and their capabilities have steadily expanded since then.
Today, utilities can draw on trenchless technologies for the installation of new assets, or the rehabilitation of their existing assets, and use options including horizontal directional drilling (HDD), microtunnelling, auger boring and pipe jacking for new installations; and slip lining, spiral wound lining and cured in place lining for rehabilitation.
Trenchless technologies are often admired for the innovative options that they provide utilities with, but the reality is, these impressive technologies don’t come without a cost premium – which has traditionally held back the wider uptake of trenchless technologies as the installation and rehabilitation methods of choice over open cut methods.
The argument from the trenchless industry is that organisations assessing tenders need to look beyond the bottom line – cost – and consider the triple bottom line of environmental, social and financial impacts.
In today’s climate of increasing awareness of environmental impacts, and the need for a sustainable approach to any construction projects, trenchless technologies have a lot to offer.
Environmental awareness
The environmental impact of new construction projects in utilities has never been more important than it is today. Increasingly, utilities are focused on their impacts on the environment, and the ways in which they can tread lighter.
Environmentally responsible construction can take on many different forms. In the utilities industries, a key focus for limiting the impact of new constructions focuses on limiting the damage and disruption caused to the surrounding environment, and local flora and fauna, during the construction phase.
These are not the only ways that utilities can deliver new assets in an environmentally responsible manner; but they are areas in which trenchless technologies can play a significant role.
In Queensland, the Australia Pacific LNG (APLNG) project and Queensland Curtis LNG (QCLNG) projects both used the trenchless solution of HDD to meet the exacting environmental standards required for the projects to be executed in full.
Both projects involved the construction of large diameter transmission pipelines from the Surat and Bowen basins to the coast of Queensland.
HDD was then used to cross “The Narrows”, a small section between the mainland coast and Curtis Island, where the gas is processed and shipped to Asian markets.
The Narrows HDD crossing involved the installation of two 42-inch transmission pipelines, via HDD, within the environmental footprint usually required to install one pipeline.
Located near the most sensitive terrestrial and marine environment in Australia, the Great Barrier Reef Marine Park, HDD was deemed to be the least invasive method of pipeline construction in this environmentally significant area.
By utilising HDD, the project proponents were able to minimise the amount of terrestrial disruption caused throughout the project, which means less work at the end of the project to replace displaced earth. It also meant that the impact on the surrounding flora and fauna was minimised.
Consider the community
Utilities that are undertaking upgrades, repairs or installing new assets in congested, urban spaces are faced with the challenge of how to execute the works while minimising the impact on the surrounding community.
In many cases, carrying out open trench works – and the associated disruptions to road and foot traffic, and local businesses, among others – will simply not be tolerated.
Trenchless technologies such as HDD, microtunnelling, pipe relining, cured in place lining, pipe jacking and auger boring all operate within a significantly smaller site footprint than traditional open cut trench projects.
Generally, there will be entry and exit points for these technologies, with the ground between these points able to remain undisturbed throughout the duration of works with business able to continue as usual.
Further, because the sheer volume of ground disrupted is minimised, crews are often able to get in, get the job done and close the job site quicker than if full trenches are required – meaning that the already reduced disruption to surrounds will affect the community for a shorter amount of time.
It’s not just the bottom line
In challenging market conditions, cost is often the deciding factor when assessing tenders for construction projects.
However, focusing on the initial construction cost, rather than considering the overall lifetime operating cost, can be a short-sighted approach.
Take for example the installation of sewer mains. Utilities have the option of installing gravity mains, which slope downwards to propel sewage forward, or they can install sewers in which sewage is propelled by pumps.
It’s often cheaper to install a pump propelled sewer line via open trench methods but such an installation will also come with the lifetime cost of maintaining the pumps that propel the sewage, not to mention the energy cost associated with running these pumps.
Installing a gravity sewer by methods such as microtunnelling may have a higher initial installation cost, but once up and running, the ongoing operation and maintenance costs are significantly lower.
Utilities need to consider the overall lifetime costs of any new installation, to ensure they really are securing the best value for their money.
A sustainable choice
Trenchless technologies offer utilities a range of options for the installation and rehabilitation of their assets which offer triple bottom line benefits – environmental, social and financial. In short, they can offer utilities a sustainable choice.
When weighed up against the other options in the market, trenchless solutions offer significant benefits. The lesson to utilities: look beyond the bottom line for your next construction or rehabilitation project, and consider the broader benefits these impressive technologies can offer.
