RPS delivers important research for UKWIR on Interruptions to Supply

Ofwat defines supply interruptions as a period when properties are without a continuous supply of water. A property is considered to be without a supply of water when it is lost from the first cold water tap – operationally equivalent to ≤3m pressure at the main (adjusted for any difference in ground or property level).

UK Water Companies are required to meet performance targets for ITS incidents and property hours so have an inherent interest in continuous improvement to either prevent incidents or rapidly react to reduce the length of incidents. With an Ofwat mandated Outcome Delivery Incentive (ODI) penalty attached to ITS, there is an economic driver to reduce the occurrence and length of ITS incidents, as well as the customer impact and reputational damage associated with press coverage of large incidents.

What are the potential causes of ITS?

• Mains bursts
• Air locks
• Pressure control failure
• Exceptional demand
• Blockages
• Network operation
• Production outage
•  Reservoir outage
• Planned Maintenance

Some of these causes can be controlled by robust planning processes, however, the unexpected can happen where unpredictable elements have influence, such as extreme weather events. Other elements whilst unforeseen in the case of individual events, can be mitigated through proactive asset maintenance and replacement by implementing structured processes and controls as well as improved asset and network knowledge.

About the Project

The purpose of the project was to provide answers to a numbers of questions which relate to UKWIR BQ3 - Interruptions to Supply - How do we achieve zero interruptions to supply by 2050?:

Provide a clear understanding of the major root causes of ITS across the industry to therefore focus future research appropriately and provide answers to the following questions:

• How do we know how close we are to zero interruptions as an industry and how are we progressing towards this?
• How do we understand the relative ITS impact of different pipeline asset diameters and materials failures?
• How can we better understand the wider range of ITS Root Causes affecting performance?

Working with our project partner AMCL, we engaged with UKWIR project steering group (PSG) members to obtain data from UK and Ireland water companies to be able to undertake analysis and provide answers to the questions.

There were many positive aspects to the project from initiation including the participation of industry colleagues in group workshops which helped to establish a project baseline and initial direction and develop co-operation which provided a deeper insight into the work involved. However, we also faced some challenges in that not all invited Water Companies engaged with the project and the level of engagement was not uniform across contributing Companies. We also found that there was huge differences in the types of ITS incident data collected and it lacked consistency in format, depth and detail.

Much of the incident and investigation information provided was held in excel based formats with limited fields and pick list options which made it difficult to capture levels of detail required for the type of analysis which would provide the insight granularity required to completely answer the questions set out in the project scope.

Something that was commonly identified as a reason behind the difficulty of companies being able to provide this data is that much of it is obtained and processed through different technology and platforms and it was very difficult for them to be able to link burst data to ITS and to extract useful detailed data into a structured format available for analysis.

At the end of the project we felt we could give a qualified indication rather than a clear understanding of the major root causes of ITS with the majority being (unsurprisingly) from network causes, with ‘bursts’ being the significant proportion of those. The ‘qualified’ being down to the consistency and quality of the data provided by all the contributing companies and that not all UK and Ireland water companies had been involved in the project.

What we learnt

• The regulatory framework is based around event duration, reducing the focus on the failure Root Cause Analysis (RCA).
• The detail of ITS and the corresponding RCA data is inconsistent across companies, often only data necessary for incident management is retained.
• ITS data sets in company systems do not always easily support post event analysis or the detailed RCA and classification needed to drive lifecycle decision-making improvements to reduce ITS.
• Data is held in unconnected systems making it difficult to link together or get meaningful datasets.

How did we answer the BQ3 Questions?

Provide a clear understanding of the major root causes of ITS across the industry to therefore focus future research appropriately?

Whilst we couldn’t give a clear and definitive answer due to the limited set of data available to us, there was a clear indication that pipe failure is the largest reason given for ITS incidents across the industry.  For one company, where detailed root cause could be evaluated, over half of ITS were due to network condition, with the next largest causes being business process control. What was clear that future collaborative research into the area would greatly benefit from a much broader and consistent data set, and this was reflected in the recommendations for future industry actions and focus.

How do we know how close are we to zero interruptions as an industry and how are we progressing towards this?

Based on individual ITS details that had been provided, it was evident that  there had been a reduction in incidents over 2020-21 and 2021-22, the prior two full reporting years available for the project. It also seemed evident that overall durations were reducing, but again the same qualification on the quality and breadth of data available, prevented a clearer indication of the situation for the whole of the UK and Ireland water industry.

How do we understand the relative ITS impact of different pipeline asset diameters and materials failures?

The detailed burst data available for analysis was limited so we were unable to give a definitive understanding of the impact of the different diameters and materials that could be applicable to the UK and Ireland industry. The data showed that the significant proportion of ITS incidents where pipe failure was the cause, pipe material was recorded as Polyvinylchloride (PVC), Asbestos Cement (AC) and Cast Iron (CI). These results could only be seen as reflective of the companies that supplied pipe materials data but will likely be applicable and familiar to many other companies.

It was evident that the larger main failures (diameters >200mm) can lead to large scale (complex) and longer ITS incidents, however these are not common and the high frequency of incidents on smaller pipes  (diameters <100mm) is more significant to overall ITS reporting.  More than two thirds of the reported duration was associated with incidents on diameters <225mm.

In terms of pipe material, the greatest impact on ITS duration was associated with AC and PVC pipes. CI, Medium density polyethylene (MDPE) and Black Polyethylene (PE) were the next highest impact materials on ITS incident duration.

Generally, although the CI mains are older, this re-iterates the accepted industry view that AC and PVC mains are a significant problem across the UK and should feature more prominently in asset management decision-making associated with capital interventions.

How can we better understand the wider range of ITS Root Causes affecting performance?

Our main recommendations are around providing a process-based data framework for recording incident details and data as well as decisions made during the RCA process. This will allow for a broader and deeper data set to be available for both individual companies to connect root cause and duration allowing a clearer understanding of how to improve ITS performance and to enhance intervention decision-making around asset maintenance programmes and replacement strategies.

How do we move forward from here?

In the report we make several recommendations with the main one being for UK Water companies to look at how they can improve collecting ITS data in line with the ITS register and investigations standards specification included in the report appendices. This standard was proposed and developed in discussion with representatives from the contributing water companies.

The standard highlights that a consistent, process-based approach is essential for collecting a baseline set of data for each incident including a clearly defined incident root cause and incident duration causes, as well as a structured method of capturing data.

One of the challenges highlighted during our conversations with water companies was that the ability to link data across diverse systems to capture incident insights is not always easy. Throughout the report development and by working with the data provided, it became clear that focus on building interfaces to automatically capture data will provide benefit to companies. The consequence of implementation the recommended process-based approach (including the linking of systems) will be that incident review does not need to include resources deployed to acquire and transform data. Instead, effort can be concentrated on using the data to develop detailed RCA and other quality controlled data feeding into business process and asset planning. This will be key to providing an ever clearer understanding of the major root causes of ITS, and to provide data which is critical for trend and forecasting analysis that would be available in a single location and increase confidence in the data that is available for all asset management decision-making. It will also provide companies with the ability to provide a more comprehensive and representative set of data that can be drawn upon for future research and provide clearer answers to the question.

To know more about how we work within the UK and Ireland water industry, do read about our work in Water Services.