Trenchless renewal of Unitywater’s dn100 water main – Narangba

Abstract

Ageing pressure water main infrastructure represents a significant risk to Water Authorities throughout Australia and New Zealand (A/NZ). Asbestos Cement (AC) pipe makes up around 40,000 to 50,000km of these assets across the A/NZ region. Most of these AC assets are reticulation sizes (DN100/150) and, with an average life expectancy of around 60 years, represent a major financial, environmental and social risk as they come to the end of their service life. Unitywater has a significant cohort of these AC water main assets and have been actively searching for a sustainable renewal solution to replace traditional methods such as lift and relay. Traditional methods can be slow, expensive and risky, with no known safe exposure level for asbestos. The RediFlow® technology bundle by Interflow is one such solution to address the desires of Water Authorities, such as Unitywater, for safe and sustainable methods to renew these essential assets. The RediFlow® technology bundle is the amalgamation of Interflow’s innovative die-reduction slip lining technology (TiteFlow® H112) and their patented in-line water stop technology (Infrastop®). Together, this pairing offers a sustainable, trenchless renewal option for existing AC watermains. Recently, Unitywater partnered with Interflow to trial RediFlow® on 481m of DN100 AC reticulation pipe in the suburb of Narangba. This paper will walk through the trial from inception to delivery and share the results of this innovative process, which delivered a cost-effective solution with low environmental and community impacts as well as minimal asbestos exposure risk.