Sustainable Approach for the Replacement of Water Mains: Environmental, Social and Economic Considerations.

Water mains in many areas of London and some parts of the Thames Valley are still amongst the oldest and in need of replacement. The mains have been susceptible to corrosion, leaks and subsequent breakage, causing water wastage, continuous maintenance cost, social and environmental impact because of disruptions to water supply to local communities, road congestion and damage to the road infrastructure. The aim of this study is to examine the factors, which determine the methods adopted for the replacement of water mains and the economic, environmental and social considerations that underpins the decision-making process. The research method adopted is a mixture of quantitative and qualitative approaches using surveys and interviews. This trenchless techniques are preferred due to lower cost, speed and productivity. Directional drilling was selected due to its cost, speed and productivity but also because it is the most customer driven method to ensure a constant supply of water. There is a need for a sustainable procurement approach incorporating social and environmental factors which affects productivity such as ground conditions, unknown utilities, the impact of water disruption on residents/schools and delays due to obtaining road access permits. Involvement of Local authorities in the design and accessibility discussion can help speed up the process and increase productivity.