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CDEnviro outlines the future of NDD

Large scale investment in Australian infrastructure means that the country’s concrete landscape is set to change. CDEnviro’s Diarmaid Connaire looks at what it could mean for the NDD market.

by Diarmaid Connaire, CDEnviro Business Development Manager

With a AU$50 billion government investment in infrastructure, Australia’s roads and railways are set to change and it is the opportune time to be involved in the construction and civil sectors. Large scale reshaping will be seen across all of Australia, but particularly in New South Wales, Victoria and Queensland.

Examples include the AU$98.4 million investment into Sydney’s Rail Future, AU$500 million towards the widening of the Monash Freeway and the AU$518.4 million allocation for the Moreton Bay Rail Link. These large investments, among many others in Australia, aim to spike economic growth, increase productivity and create new jobs.

As well as increasing productivity and creating jobs, the government plans for the infrastructure investment to ease congestion. Sydney – although known for her unspoilt beaches, mesmerising architecture and thriving restaurants – is infamous for its notoriously congested roads.

Many people believe that congestion is even affecting the quality of life for ‘Sydneysiders’, consuming valuable time with travel to work, school and airports, among other every day destinations. The same could be said for our other major cities, such as Melbourne and Adelaide; however, will the infrastructure investments change things for the better for our cities?

Although the government has promised a remedy for Sydney and other cities’ ‘condition’, it is ironic that congestion is set to get much worse before it can get better. Noisy roadworks will not only stop traffic, but will also require more vehicles to transport waste away from construction sites.

It is clear that congestion will increase in the short-term, but it may be the only way to see long-term improvements.

The non-destructive solution

To minimise the impact on the environment and our communities, non-destructive digging (NDD) is sure to be a common method used across the country for these infrastructure projects. Contractors use high-pressure water and a vacuum to break up and remove earth as a safer and more precise way of excavating, exposing electrical cables and underground pipes without risk of damaging them.

This is a less time consuming and much safer alternative for the infrastructure, as well as the personnel, than using traditional digging machinery. The process also creates less noise and dust pollution for the surrounding community. With increased productivity, efficiency and safety the benefits of NDD are clear, but even this process brings with it some problems.

Challenges on the horizon

NDD, although an effective and safe alternative to conventional digging, is not without its drawbacks. Like any digging or drilling process, NDD produces waste and the logistics of transporting this waste is both expensive and time consuming.

High and rising landfill costs are crippling those involved in NDD. In South Australia, contractors are charged AU$57 per tonne for disposal of their waste; in Victoria this figure is AU$60.52 per tonne, meanwhile New South Wales charges a levy of AU$133.10 per tonne of waste.

With an increased awareness that our resources are finite and that we need to promote a circular economy, landfill costs are likely to rise further in the future. This means that disposal costs for contractors are sure to climb and now, more than ever, is a time to be rethinking what we do with NDD waste.

Disposal costs is not the only problem contractors are faced with when deciding what to do with their NDD waste. The majority of the government’s investments in infrastructure are taking place in cities where the demand for improved transport and roads is highest.

However, the waste depots for drilling muds are often outside of the city and therefore require long journeys. Evidently, both the transport and the manual labour involved incurs costs for the contractor.

In addition to high disposal and transport costs, the consistency of NDD waste brings with it another problem. NDD waste is very wet, making its disposal and management difficult; most landfills will not take the waste in this form and the facilities that do accept NDD muds often have limited capacities to process the waste in its slurry form.

Benefits of waste treatment

With rising disposal costs and hidden costs associated with transport and truck down time, treatment of NDD waste should be more than just an afterthought. Often a popular solution to deal with hydro excavated muds is to simply let it dry.

But this method is neither efficient nor sustainable, particularly in the winter months when the drying process is extended. Treatment of NDD waste allows contractors to recover spadable outputs of washed sand, aggregates and recycled water.

Treatment goes much further than dewatering by adding value to the products for reuse or resell. Through resource recovery, contractors can turn a waste stream into a revenue stream.

Alternatively, the spadable outputs can be kept and reused onsite. Evidently, this means businesses reduce the cost of buying new materials, but less obvious is the savings made from eliminating the need to transport new materials to site.

Localising treatment onsite

Waste treatment significantly reduces expenditure on landfill and transport but an onsite waste treatment system will go one step further, eliminating these costs completely. Having technology in place to treat NDD enables contractors to receive waste material directly from a truck.

Treatment systems, like CDEnviro’s range, can be specifically designed to recycle sand and oversize, condition wastewater, dewater clay and reuse water. Treating the waste onsite is not only easier but also beneficial to the company and to the community.

Localising services stimulates the local economy and the productivity of the individual business. Reduced overheads and eliminated travel costs mean that contractors can pass these savings on to their customers, ultimately making them more competitive in the market.

The future of NDD

NDD has, and will continue to, play a vital role in the improvement of our infrastructure. With the ability to treat NDD waste, the process not only is safer and more effective but can be more profitable too.

Competition in the construction business for the government’s projects will continue to be competitive, but treating NDD waste onsite could allow businesses to become more competitive while benefitting their local community. It is also important to remember that reduced landfill, reduced transport and reusable products not only benefit us at a local level but at a global level, which is essential for a cleaner environment.

For more information visit the CDEnviro website.

If you have company news you would like featured in Trenchless Australasia contact Managing Editor Nick Lovering at

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