MegaProjects and Green Infrastructure: The Trenchless Revolution

MegaProjects and Green Infrastructure: The Trenchless Revolution

Trenchless International catches up with ISTT Immediate Past Chairman Dr Samuel Ariaratnam

Monday, December 19, 2016

It is a truth universally acknowledged that the trenchless industry will be constantly compared to open cut excavation - be it in costs, efficiency or emissions output. However, when Trenchless International caught up with industry stalwart Dr Samuel Ariaratnam prior to his journey to Australia as a course leader, he said the comparison was continuing a steady swing to trenchless' favour. "You can pretty much give a ball-park estimate of 20-30 per cent cost savings for opting for a trenchless method compared to an open-cut method in a built up area," he said. "In some cases there may even be

projects, making it a more competitive market," he continued. "But costs are also coming down because the equipment and technologies have gotten so much better, allowing projects to be completed more efficiently and to a higher standard of quality - a crucial factor because time is money in the construction industry." Dr Ariaratnam cited the horizontal directional drilling (HDD) sector and the ever-evolving HDD rig as evidence of this. "For example, an HDD rig from 15 years ago is different from a rig today. It is both quicker and more efficient, allowing projects more favourable for trenchless from a carbon footprint or environmental perspective, continued Dr Ariaratnam. "Trenchless wins out every time: there is less equipment doing more focused excavation, which results in quicker projects that require minimal surface restoration -  if any," he said. Not only have many studies and technical papers been published around the world on the topic, tools such as carbon calculators have also been developed. Dr Ariaratnam himself has developed a tool known as eCALCTM for HDD rig specialist Vermeer, construction and rehabilitation options, Dr Ariaratnam said price was still unfortunately the overriding factor. However, he said carbon emissions are becoming an increasingly discussed topic. "I think that this is just a matter of changing the myopic thinking of people," he said. "As the world continues to focus on sustainability, you are going to find that the carbon - or environmental footprints in general - are going to be a part of the bidding process of the project. It is not just going to be on cost and schedule, but also environmental impact. I'm not sure exactly how it will be incorporated, but I think it will eventually be incorporated."

TRENCHLESS GOES GREEN Similarly related to the realms of environmental footprints is the increasingly hot topic of `green infrastructure', particularly in urban development and construction. When queried if Trenchless Technology qualified as green infrastructure, Dr Ariaratnam was quick to agree. "Trenchless fits into the idea of green infrastructure very well," he said. "Green infrastructure, in a nutshell, is building within nature. Trenchless construction, installation or rehabilitation is very effective at helping to preserve vegetation and biodiversity. "Whether trying to improve stormwater quality, being an indelible part of a sustainable energy project, or assisting with improving air quality, we are minimising environmental and habitat disruption. It can be thought of as being aligned with nature." While the materials used in trenchless techniques were not necessarily `green' per se,especially concrete, clay, PVC or HDPE, the methods and technological processes certainly fit the bill, said Dr Ariaratnam. "The technologies used in the industry really help - there is a kind of intrinsic value to the infrastructure because we are building within the boundaries of nature. There is also better air quality thanks to reduced emissions." The final way that Trenchless Technology can be considered green is in the vital supporting role it plays in many of the world's renewable energy and sustainability efforts, said Dr Ariaratnam. "Trenchless Technology is also often used to help install pipelines for sustainable energy projects, such as cleaner burning natural gas pipelines or the subterranean cables of renewable energy installations. "It also commonly helps build and rehabilitate stormwater lines and install drainage infrastructure to better reduce flooding. This is all without disrupting the nature and biodiversity systems on the surface."

ON THE EXPLOSIVE DANGER OF CROSS BORES One initiative Dr Ariaratnam is particularly involved with in North America is raising awareness on the extremely dangerous issue of cross bores. "Cross bores generally occur on buildings or houses with sewer laterals or assets that are typically non-metallic and very difficult to locate," he told Trenchless International. "In such an instance, a small gas distribution main is unknowingly installed through the asset, thereby `crossing' or `bisecting' it. Years later, the blocked asset backs up. A plumber is called, who comes in with a mechanised tool and puts it down the toilet and through the asset. They nick the gas line, which could blow up the whole building." To raise awareness of the dangers of cross bores for the civil construction industry, Dr Ariaratnam has been working with organisations such as the Distribution Contractors Association to produce position papers to bring the issue to the attention of government agencies such as the United States Congress. According to Dr Ariaratnam, the issues first arise within the legislation for the responsibility for locating sewer laterals, which is stipulated as being either "the owner or operator of the sewer lateral". "The word `or' is a big problem," explained Dr Ariaratnam. "The owner is the homeowner, but the operator is the utility getting revenue from the sewer. So because of the word `or', you can't expect the homeowner to find a way to locate an asset beyond using a one-call Call Before You Dig service, and then the utility says `well, we don't know where it is and we're not going to locate it because we don't have to', thanks to this word `or'." This stalemate is worrisome for gas utilities, he continued. "We have what we call ticking time bombs. There are a lot of laterals out there in North America that have been bisected - we just haven't hit them yet, or they haven't backed up yet." To stave off a potential disaster, Dr Ariaratnam is helping to raising awareness amongst plumbing and `rotor rooter' contractors. The initiative is large in scope, with Dr Ariaratnam working on it for the better part of a decade.