Environmental influences in pipe corrosion (EPiC)

Yorkshire Water (YW), Scottish Water and Dwr Cymru Welsh Water (WW) have extensive networks of clean/waste water pipes made of a variety of materials (ferrous, plastics). It is recognized that pipe failure occurs through a complex set of interactions including corrosion, factors such as geohazards (ground movements), environmental factors (e.g. slope) and other external factors (e.g. traffic vibration, surge demand). When these failures occur it results in loss of supply to properties, causes public highway closures and potentially long-term inconvenience to business and the general public. Changing ground moisture and thermal profiles caused by environmental change may enhance the probability of drought or flooding. In particular, this may increase the impact of ground conditions on the pipe network, exacerbating future failures (causing asset loss, exfiltration undermining of infrastructure and contamination). Increased leakages, particularly in drought years are a potential major concern to the regulator, OFWAT. This project aims to help water companies manage the repair and maintenance of their pipe networks through the development of a spatial model relating pipe failure data to a range of environmental, geohazard and external factors. The model will provide evidence about the primary factors in pipe failure which water companies can use to improve pipe network infrastructure management and resilience within a changing climate.

These outputs can be used by water company engineers (i) to provide information regarding pipe failure that can be used to improve design standards for different pipe materials (e.g. plastic, ferrous, concrete) and installation, (ii) to be used as a screening tool to identify areas where additional factors not related to model covariates are causing high incidences of pipe failure and (iii) to identify areas where additional engineering solutions can be used to build climate resilience into the network, particularly in relation to those geo-hazards most influenced by climate (e.g. shrink-swell clays). The proposed work includes a scoping study and exemplar of how those outputs can be delivered to the for water companies. Advice on functionality and content will be sought from YW and WW. Options include the possible integration of outputs into existing company systems or a stand-alone web based system. The output data could be presented as maps, GIS layers or digital services and will be based on significant model covariates presented as individual factors (GIS layers) or combined maps and hazard information. If a web based system is considered preferable we will provide an exemplar service to the water companies demonstrating how their data may be accessed either on a public good basis (via a public portal such as UKSO.org) or via a secure service to commercial users (secure web map services).

Keywords: pipe network, water leakage, geo-hazards, spatial model,

The impacts of the project outputs will be determined by (i) increased understanding of the factors involved in pipe network failures, the (ii) engineering solutions adopted by the water companies as a result of this project's outcomes and (iii) the subsequent beneficial changes to the infrastructure investment planning.

Measures of success of this project initially will be its ability to inform water companies planning policy and 5 yearly investment plans through:
a. Indication from WW and YW that project results will be incorporated into planning activities (via personal communication)
b. The inclusion of model outputs in YW and WW infrastructure investment strategy
c. Submissions to OFWAT developing awareness of the project, measurable through citations in YW, SW and WW annual reports, conference talks and discussions with other water companies.

Other impacts, over the longer term include:
a. The model methodology creating sufficient interest that there is uptake by other water companies and underground asset holders (e.g. gas)
b. Funding from industry for further development
c. The development of a new UK- wide pipe failure product.
d. Incorporation of model results into existing systems/working practices

For this project proposal we have linked up with three partners that have a genuine interest in our approach to examining the causes of pipe failure within their networks. We have previously worked with YW on a pilot study and they have been very enthusiastic to be involved the next stage of our work. Welsh Water with whom BGS have had previous partnerships with, particularly through our work on sustainable urban drainage (SUDS) were keen to take up our offer of involvement, whilst SW approached us having heard about the project via the infrastructure initiative. We therefore have pre-endorsement from the industry and a strong basis for communicating to other water companies.