Timothy Farewell
Cranfield University
How can leaks from corroded water mains be reduced?
The challenge
Failures in the water distribution network represent a major cost to any water company. A significant proportion of bursts and leaks are associated with the corrosion of cast-iron pipe systems laid without protection earlier this century. In many places, these are now performing so badly that replacement or repair is a matter of urgency.
Replacing water pipes is expensive. To spread the cost, and prioritise the worst situations, there is a need to understand both the degree of intensity of the corrosion process and its spatial extent, and in particular to understand the relationship between soil and climate characteristics and pipe failures.
Failures in the water distribution network represent a major cost to any water company. A significant proportion of bursts and leaks are associated with the corrosion of cast-iron pipe systems laid without protection earlier this century. In many places, these are now performing so badly that replacement or repair is a matter of urgency.
Replacing water pipes is expensive. To spread the cost, and prioritise the worst situations, there is a need to understand both the degree of intensity of the corrosion process and its spatial extent, and in particular to understand the relationship between soil and climate characteristics and pipe failures.
The solution
Researchers at Cranfield University have developed the Leakage Assessment from Corrosivity and Shrinkage (LEACS) system, a valuable tool for reviewing and planning pipework repair or renewal.
LEACS offers a 'geo-spatial' approach, using a Geographical Information System (GIS), and employing powerful tools to assess and visualise the risks of potential mains failure. The LEACS system embodies a number of models (eg soil corrosivity) and draws upon a wide range of environmental data, including soils data from the NSRI's Land Information System (LandIS - the largest computer-based information system of its kind in Europe).
Using GIS models, the data in the LEACS system can be superimposed on a client’s burst locations. A statistical analysis of the correlation of burst location with the NSRI data can then be carried out to help identify areas of highest risk.
The LEACS system has been developed for application across all geographical areas of the United Kingdom, and is used widely throughout the water utility sector to assist in the Asset Management Planning (AMP) process, as well as by the national regulator the Environment Agency.
Resulting benefits
Cranfield researchers recently examined the effects of weather and soils upon the water main network of Anglian Water, which had seen an increase in the number of burst water mains over the period 2008-2012. Using the LEACS system, bursts were compared against a range of soil, environmental vulnerability, and climate datasets.
Cranfield was able to provide Anglian Water with a geohazard assessment of the environmental factors causing increased incidence of burst water mains. This helped the company to identify what measures could be employed to reduce future occurrences, and supported informed decision-making on replacement strategies and upgrade options.
Future directions
To be provided.
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