Comparing the costs - Trenchless versus traditional methods

As communities and regulators place increasing demand on maintaining and improving infrastructure in cost effective and socially acceptable ways, there is an increasing trend in the development and usage of trenchless technologies to provide the best solutions.

Since 1993, the growth of trenchless technology in Australasia has steadily increased in most industries, with the telecommunication and gas utilities the most significant sector to take advantage of the technology. The potential use and application of trenchless technology in the rehabilitation or renewal of water services in Australasia is staggering, with an estimated 96,000 km of sewer and sewer pressure mains that are approaching or exceeding their design life. As more work has been undertaken and more industry players have become involved, unit costs have generally decreased and proven track records have been established with a wider embrace of trenchless technologies. Recent studies by the Australasian Society for Trenchless Technology (ASTT) have shown there are more than 60 proprietary products and methodologies for trenchless repair and renovation of pipelines, and they are used by more than 70 utilities in Australia and New Zealand.

Fully trenchless or partially trenchless, (where some excavation is required) technologies offer many benefits as a methodology for rehabilitating or renewing pipelines that mitigate some of the social and environmental impacts and often some of the cost of open cut excavations. Competition for space in service corridors, the intensification of urban and residential developments, the risk to the public and contractors, and the impact on property owners and the community environment in a growing number of cases limit the options for open excavation.

This paper discusses the comparisons of cost and the factors that impact on a project, the environment and society that should be considered when selecting the appropriate pipeline construction methodology.