Mountain Highway AC Water Main Renewal – Demonstration of a New Trenchless Alternative

Abstract

Like Water Utilities throughout Australia, South East Water in Victoria has asbestos cement water mains in its distribution network that are reaching the end of their service life. South East Water’s 1,600 kilometres of AC mains were mostly laid in the 1950’s and 1960s, and like other Water Utilities, were mostly in DN100 and DN150 sizes. South East Water has been one of Australia’s leaders in investigating alternatives for overcoming the unique issues posed by deteriorating asbestos cement pipelines. The danger posed by exposure to asbestos fibres means that the normal trenchless option of replacement by pipebursting isn’t usually acceptable, and excavation and replacement requires extensive safety measures to be implemented. The Co-Operative Research Centre Project to evaluate Cured-in-Place pressure liners and polyurea-based formulations of spray liners addresses this issue. The Mountain Highway AC Water Mains Renewal Project demonstrated another alternative, offered by Interflow Pty Limited for the first time on a substantial project. Some 1.4 kilometres of DN100 AC water mains was lined by diedrawn polyethylene pipe using the Interflow Titeflow process. This Paper details how issues associated with die-drawn polyethylene lining of such a small diameter were addressed and how the result of the project showed that this is a viable alternative for renewal of deteriorated asbestos cement water mains. Page 1 of 6 No-Dig Down Under 2021 Mountain Highway AC Water Main Renewal John Monro