Assessing impacts of the private sewer transfer on UK utilities

Abstract

In October 2011, Section 105A (S105A) of the Water Act of 2003 transferred the ownership of previously privately owned sewers to the ten water and sewerage companies operating in England and Wales. In light of this recent legislative change, this paper discusses the asset management challenges associated with the private sewer transfer before exploring a decision-making framework used by South West Water to establish a more accurate understanding of the extent and likely condition of their newly transferred network. The framework has allowed South West Water to initiate a proactive asset management programme with the aim of addressing the deteriorating condition of these assets while also tackling their associated serviceability performance. Initially, a number of geospatial (GIS) tools are used to provide an estimate of the likely extent of the transferred network before a well-established public sewer deterioration model is used to predict the condition and operational performance of these S105A assets over time. The outputs from this study have better equipped decision makers with information surrounding the deterioration and collapse rates of these newly transferred sewers over time. The information has been used to help formulate strategic business planning decisions, for example, by using cost vs. benefit analysis tools to model different investment scenarios across the network.